WorldWideScience

Sample records for critical pathways radionuclides

  1. Critical Radionuclide and Pathway Analysis for the Savannah River Site, 2016 Update

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hartman, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-08

    During the operational history of Savannah River Site, many different radionuclides have been released from site facilities. However, as shown in this analysis, only a relatively small number of the released radionuclides have been significant contributors to doses to the offsite public. This report is an update to the 2011 analysis, Critical Radionuclide and Pathway Analysis for the Savannah River Site. SRS-based Performance Assessments for E-Area, Saltstone, F-Tank Farm, H-Tank Farm, and a Comprehensive SRS Composite Analysis have been completed. The critical radionuclides and pathways identified in those extensive reports are also detailed and included in this analysis.

  2. CRITICAL RADIONUCLIDE AND PATHWAY ANALYSIS FOR THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, T.

    2011-08-30

    This report is an update to the analysis, Assessment of SRS Radiological Liquid and Airborne Contaminants and Pathways, that was performed in 1997. An electronic version of this large original report is included in the attached CD to this report. During the operational history (1954 to the present) of the Savannah River Site (SRS), many different radionuclides have been released to the environment from the various production facilities. However, as will be shown by this updated radiological critical contaminant/critical pathway analysis, only a small number of the released radionuclides have been significant contributors to potential doses and risks to offsite people. The analysis covers radiological releases to the atmosphere and to surface waters, the principal media that carry contaminants offsite. These releases potentially result in exposure to offsite people. The groundwater monitoring performed at the site shows that an estimated 5 to 10% of SRS has been contaminated by radionuclides, no evidence exists from the extensive monitoring performed that groundwater contaminated with these constituents has migrated off the site (SRS 2011). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people. In addition, in response to the Department of Energy's (DOE) Order 435.1, several Performance Assessments (WSRC 2008; LWO 2009; SRR 2010; SRR 2011) and a Comprehensive SRS Composite Analysis (SRNO 2010) have recently been completed at SRS. The critical radionuclides and pathways identified in these extensive reports are discussed and, where applicable, included in this analysis.

  3. Critical pathway studies for selected radionuclides. Part of a coordinated programme on environmental monitoring for radiological protection in Asia and the Far East

    International Nuclear Information System (INIS)

    Bhat, I.S.

    1980-04-01

    The programme carried out critical pathway studies for selected radionuclides ( 60 Co, 63 Ni, 59 Fe, 54 Mn, sup(110m)Ag, 106 Ru and 144 Ce) and assessed population exposure in the vicinity of Tarapur Atomic Power Station. The following topics are covered under the programme. (i) Demographic study of dietary habits and consumption data for Tarapur population. (ii) Concentration and accumulation of radionuclides in food products. (iii) Determination of radionuclides in sea water, silt, marine algae and marine organisms at Tarapur Atomic Power Station (TAPS) Site. (iv) Behaviour of radionuclides released to marine environment. (v) Evaluation of critical exposure pathway. (vi) Population exposure in the vicinity of Tarapur Atomic Power Station

  4. Transfer of radionuclides to man through environmental pathways

    International Nuclear Information System (INIS)

    Mitchell, N.T.

    1974-01-01

    The most widely accepted method in current use for the evaluation of environmental impact from releases of radioactivity that may cause human radiation exposure used an environmental pathway model. The more important aspects of the model involve the use of critical pathway techniques to set controls on the releases of radioactive material to the environment and to assess the human radiation exposure arising as a consequence. The basic concepts of the environmental pathway model and its application are discussed. The model depends on achieving an understanding of radionuclide behavior in the environment, from the moment of release up to the time when contamination results in radiation exposure to the public. Exposure may be as a result of contaminated material entering the body-as air, water or a foodstuff; alternatively, it may be due to radiation whose source is external to the body. For each of these types of exposure pathway the sequence of events can be divided up into a number of compartments, between which transfer takes place. Transfer along the pathway is a dynamic process and can be described mathematically in terms of transfer functions between interacting compartments. Alternatively, for the situation of a regular discharge resulting in a steady-state condition the relationship between compartments can be expressed as a 'concentration factor'. The derivation of both of these terms is described and some aspects of their use are discussed. The paper then goes on to discuss the types of environmental pathway that are encountered as a result of release of radionuclides to the atmospheric and aquatic environments. Disposal to the ground is regarded as a special case of release to the aquatic environment. Some ot the literature on the subject is reviewed in discussingthe better known pathways showing what, to date, have been the most important mechanisms of transfer of radionuclides to man. (author)

  5. Human dose pathways of radionuclides in forests

    International Nuclear Information System (INIS)

    Rantavaara, A.

    2009-01-01

    Forest soil, understorey vegetation and trees are all sources of radionuclides and human radiation doses after contaminating atmospheric deposition. People are exposed to radiation externally from sources outside the body and internally via ingestion and inhalation of radionuclides. Understorey vegetation contributes to ingestion doses through berries, herbs, wild honey, mushrooms and game meat; also trees provide feed to terrestrial birds and big game. During stay in forests people are subject to external radiation from forest floor and overstorey, and they may inhale airborne radioactive aerosol or gaseous radionuclides in ground level air. In the early phase of contamination also resuspended radionuclides may add to the internal dose of people via inhalation. People in Nordic countries are most exposed to radiation via ingestion of radionuclides in wild foods. The distribution of radionuclides in forests is changed by environmental processes, and thereby also the significance of various dose pathways to humans will change with time. External exposure is received in living environment from contaminated stemwood used as building timber and for manufacturing of furniture and other wood products. The aim of this paper is to outline the significance of various human dose pathways of radionuclides in forests considering the public and workers in forestry and production of bioenergy. Examples on effective doses are given based on two historical events, atmospheric nuclear weapon tests (mostly in 1950's and in 1960's) and the Chernobyl nuclear power plant accident in 1986. (au)

  6. Human dose pathways of radionuclides in forests; Forests ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, A. (Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, Helsinki (Finland))

    2009-06-15

    Forest soil, understorey vegetation and trees are all sources of radionuclides and human radiation doses after contaminating atmospheric deposition. People are exposed to radiation externally from sources outside the body and internally via ingestion and inhalation of radionuclides. Understorey vegetation contributes to ingestion doses through berries, herbs, wild honey, mushrooms and game meat; also trees provide feed to terrestrial birds and big game. During stay in forests people are subject to external radiation from forest floor and overstorey, and they may inhale airborne radioactive aerosol or gaseous radionuclides in ground level air. In the early phase of contamination also resuspended radionuclides may add to the internal dose of people via inhalation. People in Nordic countries are most exposed to radiation via ingestion of radionuclides in wild foods. The distribution of radionuclides in forests is changed by environmental processes, and thereby also the significance of various dose pathways to humans will change with time. External exposure is received in living environment from contaminated stemwood used as building timber and for manufacturing of furniture and other wood products. The aim of this paper is to outline the significance of various human dose pathways of radionuclides in forests considering the public and workers in forestry and production of bioenergy. Examples on effective doses are given based on two historical events, atmospheric nuclear weapon tests (mostly in 1950's and in 1960's) and the Chernobyl nuclear power plant accident in 1986. (au)

  7. Determination of key radionuclides and parameters related to dose from the Columbia River pathway

    International Nuclear Information System (INIS)

    Napier, B.A.

    1993-03-01

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. These scoping calculations may include some radionuclides and pathways that were included in the Phase 1 Columbia River pathway dose evaluations, as well as other potential exposure pathways being evaluated for possible inclusion in future Hanford Environmental Dose Reconstruction Project (HEDR) modeling efforts. This scoping calculation (Calculation 009) examines the contributions of numerous radionuclides to dose via environmental exposures and accumulation in water, fish, and other aquatic biota. Addressed in these calculations are the contributions to effective dose from (1) external exposure to contaminated river water, ( 2) ingestion of contaminated drinking water, and (3) ingestion of contaminated resident Columbia River fish. Additional information on contamination of anadromous fish and waterfowl is provided

  8. PATHWAY: a simulation model of radionuclide-transport through agricultural food chains

    International Nuclear Information System (INIS)

    Kirchner, T.B.; Whicker, F.W.; Otis, M.D.

    1982-01-01

    PATHWAY simulates the transport of radionuclides from fallout through an agricultural ecosystem. The agro-ecosystem is subdivided into several land management units, each of which is used either for grazing animals, for growing hay, or for growing food crops. The model simulates the transport of radionuclides by both discrete events and continuous, time-dependent processes. The discrete events include tillage of soil, harvest and storage of crops,and deposition of fallout. The continuous processes include the transport of radionuclides due to resuspension, weathering, rain splash, percolation, leaching, adsorption and desorption of radionuclides in the soil, root uptake, foliar absorption, growth and senescence of vegetation, and the ingestion assimilation, and excretion of radionuclides by animals. Preliminary validation studies indicate that the model dynamics and simulated values of radionuclide concentrations in several agricultural products agree well with measured values when the model is driven with site specific data on deposition from world-wide fallout

  9. Applicability of the Critical pathway analysis usually used for nuclear installations, to the control marine environment pollution by heavy metals

    International Nuclear Information System (INIS)

    Franca, E.P.; Pfeiffer, W.C.; Fiszman, M.; Lacerda, L.D. de

    1984-01-01

    The methodology of the controlling radionuclide releases from nuclear facilities by the critical pathway criteria, is given. The use of this methodology for the environmental impact studies for an industry that causes pollution is discussed. (M.A.) [pt

  10. Features of geologic structure of 'Lira' object territory and possible radionuclide migration pathways

    International Nuclear Information System (INIS)

    Belyashov, D.N.; Mokhov, V.A.; Melent'ev, M.I.; Kislyj, B.I.

    1999-01-01

    In the upper part of Karachaganak salt couple on the Lira object there are 6 artificially created chambers designed for gas condensate store at the depth 850-900 m. The chambers were created with help of underground nuclear explosions. At present a general assessment of radionuclide migration pathways from underground points of an explosion on the surrounding territories in the Lira vicinage is done. On the basis of analysis of geological and hydrogeological data by the Lira area the 4 stratigraphical and hypsometric level of possible radionuclide migration pathways could be marked out. The first of these levels related with Upper Permian saliferous sediments and it covers depths about 1 km up to couple roofing. Here the radionuclide migration will take part by tectonic breaks and fractured reservoirs, activated by energies of conducted explosions. Higher stratigraphic and hypsometric levels have been related with sediments of trias, Jurassic and partially of Cretaceous (second level), pliocene and pliocene-under Quaternary age (third level) and Quaternary sediments of Ural, Ilek and Berezovka rivers terraces (fourth level) where it is possible considerable lateral radionuclide migration in the northern and southern directions toward the couple's framing carvings

  11. Environmental radiological surveillance in perspective: the relative importance of environmental media as a function of effluent pathway and radionuclides

    International Nuclear Information System (INIS)

    Denham, D.H.

    1977-10-01

    Most published guidelines for environmental surveillance emphasize the collection and analysis of specific media (e.g. air, water, milk, direct radiation) without total regard for the potential dose impact of the radionuclides expected in or actually present in the effluent streams from nuclear facilities. To determine the relative importance of medium/nuclide combinations in environmental surveillance, the experience at major ERDA sites and at operating nuclear power plants was reviewed. Typical release rates for nuclide groupings (tritium, noble gases, radioiodine, mixed fission or activation products, and transuranics) in those effluent streams were followed through various environmental pathways. By using this scheme the environmental medium which is most prominent in the critical dose pathway to man was determined. It was also possible to determine points of short-or long-term contaminant accumulation. Following these calculations, each medium was ranked for a given nuclide/effluent pathway combination providing the relative importance of sampling specific environmental media with emphasis on the radiation dose to a critical population group. Finally, the results of these environmental pathway studies are presented in tabular form to provide ready reference for environmental surveillance program design or evaluation

  12. Environmental radiological surveillance in perspective: the relative importance of environmental media as a function of effluent pathway and radionuclides

    International Nuclear Information System (INIS)

    Denham, D.H.

    1977-01-01

    Most published guidelines for environmental surveillance emphasize the collection and analysis of specific media (e.g. air, water, milk, direct radiation) without total regard for the potential dose impact of the radionuclides expected in or actually present in the effluent streams FR-om nuclear facilities. To determine the relative importance of medium/nuclide combinations in environmental surveillance, the experience at major ERDA sites and at operating nuclear power plants was reviewed. Typical release rates for nuclide groupings (tritium, noble gases, radioiodine, mixed fission or activation products, and transuranics) in those effluent streams were followed through various environmental pathways. By using this scheme the environmental medium which is most prominent in the critical dose pathway to man was determined. It was also possible to determine points of short-or long-term contaminant accumulation. Following these combination providing the relative importance of sampling specific environmental media with emphasis on the radiation dose to a critical population group. Finally, the results of these environmental pathway studies are presented in tabular form to provide ready reference for environmental surveillance program design or evaluation

  13. Evaluation of critical pathways, radionuclides, and remedial measures for reducing the radiological dose to returning populations at a former nuclear test site

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W. L., LLNL

    1997-11-01

    Bikini Island, the major residence island at Bikini Atoll, was contaminated with radioactive fallout as a result of the BRAVO test conducted on March 1, 1954. We have identified the critical radionuclides and supplied radiological data needed to develop dose estimates for all possible exposure pathways. These estimates show that the major dose to returning populations would result from ingestion of cesium-137 (137 Cs) in locally grown terrestrial foods where the predicted population average effective dose exceeds current federal guidelines. Consequently, we designed several long-term field experiments to develop and evaluate methods to reduce the 137 Cs content in locally grown foods.This paper gives a general outline of the remediation experiments with a more detailed description of a preferred combined option. Our comparative evaluation on various remedial methods show that the combined option--potassium treatment of the entire islands with limited excavation of soil in village an d housing areas--will be effective in reducing the dose to about 10% of pretreatment levels, and offers very significant benefits with respect to adverse environmental impacts as well as savings in overall costs, time, and required expert resources.

  14. Exposure of critical group of population to water radionuclides in area affected by uranium ore mining

    Energy Technology Data Exchange (ETDEWEB)

    Hladka, E; Zavadsky, M; Solnicka, H; Heroldova, J

    1985-08-01

    Waste waters from the uranium industry are decontaminated and then discharged into water courses. Inhabitants of the nearest village on the river form the critical group with regard to radiation burden. The critical radionuclides are Usub(nat), Ra 226, Pb 210 and Po 210 whose concentrations were determined in drinking water, in the water course and in plants watered with water from the river. From obtained data on the consumption of foods of own production and of water for drinking and cooking, a weighted sum was made of the intake of critical radionuclides per year on the conservative assumption that ingestion is the sole form of intake (permissible ingestion under Notice 59/72, Coll. of Laws). Under the said criteria the intake of radionuclides from water and foods of own production is for the critical population group 27 times less than the permissible intake for the population. Decontaminated waste waters from the operation of uranium industries contribute to the radiation burden of the population only negligibly. Radionuclides from the investigated sources represent a minute fraction of permissible intake.

  15. Pathways to man for radionuclides released from disposal sites on land

    International Nuclear Information System (INIS)

    Hill, M.D.

    1986-01-01

    To predict the potential radiological impact on man of the disposal of radioactive wastes it is necessary to identify all the events and processes that could cause releases of radionuclides into the environment, to estimate their probabilities of occurrence and to calculate their consequences, for both individuals and populations. This paper briefly reviews the types of releases that have to be considered for land disposal sites and describes the mathematical models used to calculate rates of transport of radionuclides through the environment and doses to man. The difficulties involved in predicting environmental conditions in the far future are discussed, in the light of the ways in which the results of consequence calculations will be used. Assessments of land disposal of long-lived and highly radioactive wastes are briefly reviewed, with the aim of identifying the most important radionuclides and exposure pathways, and the areas where the models and their databases require improvement. (author)

  16. Sensitivity and uncertainty analysis of the PATHWAY radionuclide transport model

    International Nuclear Information System (INIS)

    Otis, M.D.

    1983-01-01

    Procedures were developed for the uncertainty and sensitivity analysis of a dynamic model of radionuclide transport through human food chains. Uncertainty in model predictions was estimated by propagation of parameter uncertainties using a Monte Carlo simulation technique. Sensitivity of model predictions to individual parameters was investigated using the partial correlation coefficient of each parameter with model output. Random values produced for the uncertainty analysis were used in the correlation analysis for sensitivity. These procedures were applied to the PATHWAY model which predicts concentrations of radionuclides in foods grown in Nevada and Utah and exposed to fallout during the period of atmospheric nuclear weapons testing in Nevada. Concentrations and time-integrated concentrations of iodine-131, cesium-136, and cesium-137 in milk and other foods were investigated. 9 figs., 13 tabs

  17. Pathway cross-talk network analysis identifies critical pathways in neonatal sepsis.

    Science.gov (United States)

    Meng, Yu-Xiu; Liu, Quan-Hong; Chen, Deng-Hong; Meng, Ying

    2017-06-01

    Despite advances in neonatal care, sepsis remains a major cause of morbidity and mortality in neonates worldwide. Pathway cross-talk analysis might contribute to the inference of the driving forces in bacterial sepsis and facilitate a better understanding of underlying pathogenesis of neonatal sepsis. This study aimed to explore the critical pathways associated with the progression of neonatal sepsis by the pathway cross-talk analysis. By integrating neonatal transcriptome data with known pathway data and protein-protein interaction data, we systematically uncovered the disease pathway cross-talks and constructed a disease pathway cross-talk network for neonatal sepsis. Then, attract method was employed to explore the dysregulated pathways associated with neonatal sepsis. To determine the critical pathways in neonatal sepsis, rank product (RP) algorithm, centrality analysis and impact factor (IF) were introduced sequentially, which synthetically considered the differential expression of genes and pathways, pathways cross-talks and pathway parameters in the network. The dysregulated pathways with the highest IF values as well as RPpathways in neonatal sepsis. By integrating three kinds of data, only 6919 common genes were included to perform the pathway cross-talk analysis. By statistic analysis, a total of 1249 significant pathway cross-talks were selected to construct the pathway cross-talk network. Moreover, 47 dys-regulated pathways were identified via attract method, 20 pathways were identified under RPpathways with the highest IF were also screened from the pathway cross-talk network. Among them, we selected 8 common pathways, i.e. critical pathways. In this study, we systematically tracked 8 critical pathways involved in neonatal sepsis by integrating attract method and pathway cross-talk network. These pathways might be responsible for the host response in infection, and of great value for advancing diagnosis and therapy of neonatal sepsis. Copyright © 2017

  18. The Potential Pathways of Radionuclide Transformations On The Location Candidate of Nuclear Power Plants in Muria Peninsula

    International Nuclear Information System (INIS)

    Simandjuntak, A.G.; Syahrir

    1998-01-01

    The potential pathways of radionuclide transformations on the location candidate of nuclear power plants in Muria peninsula proposed to explain the potential of radionuclide pathways in the ecosystem to human based on annual effective dose calculations with elimination factor ≥ 1 of dose limit 50 mSv per year. The effective dose equivalent calculations used the program package Genll. The datum found from Bureau of Statistic Centre and NEWJEC was taken into calculations. The result of this study is very useful for radiological impact and environmental impact analysis. (author)

  19. Long-Term Assessment of Critical Radionuclides and Associated Environmental Media at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, G. T.; Baker, R. A.; Lee, P. L.; Eddy, T. P.; Blount, G. C.; Whitney, G. R.

    2012-11-06

    During the operational history of the Savannah River Site (SRS), many different radionuclides have been released from site facilities. However, only a relatively small number of the released radionuclides have been significant contributors to doses and risks to the public. At SRS dose and risk assessments indicate tritium oxide in air and surface water, and Cs-137 in fish and deer have been, and continue to be, the critical radionuclides and pathways. In this assessment, indepth statistical analyses of the long-term trends of tritium oxide in atmospheric and surface water releases and Cs-137 concentrations in fish and deer are provided. Correlations also are provided with 1) operational changes and improvements, 2) geopolitical events (Cold War cessation), and 3) recent environmental remediation projects and decommissioning of excess facilities. For example, environmental remediation of the F- and H-Area Seepage Basins and the Solid Waste Disposal Facility have resulted in a measurable impact on the tritium oxide flux to the onsite Fourmile Branch stream. Airborne releases of tritium oxide have been greatly affected by operational improvements and the end of the Cold War in 1991. However, the effects of SRS environmental remediation activities and ongoing tritium operations on tritium concentrations in the environment are measurable and documented in this assessment. Controlled hunts of deer and feral hogs are conducted at SRS for approximately six weeks each year. Before any harvested animal is released to a hunter, SRS personnel perform a field analysis for Cs-137 concentrations to ensure the hunter's dose does not exceed the SRS administrative game limit of 0.22 millisievert (22 mrem). However, most of the Cs-137 found in SRS onsite deer is not from site operations but is from nuclear weapons testing fallout from the 1950's and early 1960's. This legacy source term is trended in the SRS deer, and an assessment of the ''effective'' half-life of Cs-137 in deer

  20. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Baes, C.F. III

    1987-01-01

    The Remedial Action Program (RAP) at Oak Ridge National Laboratory will include well drilling, facility upgrades, and other waste management operations likely to involve soils contaminated with radionuclides. A preliminary protocol and generalized criteria for handling contaminated soils is needed to coordinate and plan RAP activities, but there exists only limited information on contaminate nature and distribution at ORNL RAP sites. Furthermore, projections of long-term decommissioning and closure options for these sites are preliminary. They have adapted a pathway analysis model, DECOM, to quantify risks to human health from radionuclides in soil and used it to outline preliminary criteria for determining the fate of contaminated soil produced during RAP activities. They assumed that the site could be available for unrestricted use immediately upon decontamination. The pathways considered are consumption of food grown on the contaminated soil, including direct ingestion of soil from poorly washed vegetables, direct radiation from the ground surface, inhalation of resuspended radioactive soil, and drinking water from a well drilled through or near the contaminated soil. We will discuss the assumptions and simplifications implicit in DECOM, the site-specific data required, and the results of initial calculations for the Oak Ridge Reservation

  1. Doses in various parts of the biosphere due to long-lived radionuclides originating from deep geological repositories

    International Nuclear Information System (INIS)

    Bergstroem, U.; Karlsson, Sara; Nordlinder, S.

    1999-01-01

    Turnover of radionuclides and resulting doses to man were modelled for various parts of the biosphere. This was made for different scenarios of leakage of radionuclides from a deep geological repository for spent nuclear fuel and other waste. In previous studies, the emphasis was on doses from contaminated ground water represented by a well or various surface waters. This was because radionuclides were assumed to be released directly to surface water, the use of which subsequently formed the major pathway for radionuclides to agricultural areas. In the present study, radionuclides were considered to reach lakes, running waters, coastal areas, agricultural areas and peat areas. The inflow of radionuclides to agricultural areas was supposed to be from below. Doses due to direct use of contaminated ground water from a well were also considered. Altogether 44 radionuclides contained in the waste were assumed to be released during 10,000 years, with a rate of 1 Bq/year of each radionuclide, to each of the above mentioned biospheric parts. During that time, the biospheric conditions were assumed to be the same as they are today. Doses to the critical group were calculated by exposure pathways specific for each entry-point All calculations were performed with estimation of confidence due to time-dependent parameter variation and uncertainty in input values. The results indicate that drinking water from wells is not a critical exposure pathway for all studied radionuclides. Instead, inflow of contaminated water to soil and peat bogs may be crucial for illustration of doses for geological high-level waste disposal. Improved knowledge of processes at the geosphere-biosphere interface is therefore important

  2. Some considerations on the mobility of radionuclides

    International Nuclear Information System (INIS)

    Gera, F.

    1978-01-01

    The existence of radioactive substances is usually assumed to present some risk for man and the environment. As long as radionuclides are successfully contained, no harm can occur; but every containment system has a finite probability of failure. Therefore, the mobility of radionuclides along the pathways that lead from the locations of large accumulations of radioactive substances to human populations is one of the critical parameters in any realistic risk evaluation. The largest inventories of radioactive substances are in nuclear facilities such as reactors and reprocessing plants and in storage or disposal facilities for waste or spent fuel. Eventually, most radioactive materials will end up in geologic disposal facilities; therefore, the long-term risk is particularly dependent on the mobility of long-lived radionuclides in geological media. (author)

  3. Aquatic pathway variables affecting the estimation of dose commitment from uranium mill tailings

    International Nuclear Information System (INIS)

    Lush, D.L.; Snodgrass, W.J.; McKee, P.

    1982-01-01

    As one of a series of studies being carried out for the Atomic Energy Control Board of Canada, the environmental variables affecting population dose commitment and critical group dose rates from aquatic pathways were investigated. A model was developed to follow uranium and natural thorium decay series radionuclides through aquatic pathways leading both to long-term sediment sinks and to man. Pathways leading to man result in both a population dose commitment and a critical group dose rate. The key variables affecting population dose commitment are suspended particulate concentrations in the receiving aquatic systems, the settling velocities of these particulates and the solid-aqueous phase distribution coefficient associated with each radionuclide. Of secondary importance to population dose commitment are the rate at which radionuclides enter the receiving waters and the value of the water to food transfer coefficients that are used in the model. For the critical group dose rate, the rate at which the radionuclides leave the tailings, the water to food transfer coefficients, the rate of water and fish consumption and the dose conversion factors for 210 Pb and 210 Po are of secondary importance (author)

  4. Biosphere assessment due to radionuclide release in waste disposal repository through food chain pathways

    International Nuclear Information System (INIS)

    Ko, H. S.; Kang, C. S.

    2000-01-01

    The long-term safety of radioactive waste disposal is assessed by the consequence analysis of radionuclides release, of which the final step is carried out by the biosphere assessment. the radiation dose is calculated from the food chain modeling which especially necessitates site-specific input database and exposure pathways. A biosphere model in consideration of new exposure pathways has been analyzed, and a program for food chain calculation has been developed. The up-to-data input data are reflected and the new exposure pathways are considered in the program, so the code shows more realistic and reliable results

  5. TERMOD II: an interactive code for analysing intake of radionuclides by man through terrestrial pathways

    International Nuclear Information System (INIS)

    Zach, R.

    1978-11-01

    An interactive code, TERMOD II, has been written in FORTRAN IV for the PDP 10. This code allows calculation of the time-dependent input of radionuclides through terrestrial pathways to man following an acute or accidental release. TERMOD II calculates daily input rates of radioactivity and the total intake rate over specified periods. To calculate these rates, TERMOD II uses the TERMOD model developed at Oak Ridge National Laboratory. This model includes three food types which can be contaminated by fallout radionuclides. Food crops and grass can be contaminated by direct foliar deposition and by root uptake. Milk and beef can be contaminated by direct foliar deposition and by root uptake. Milk and beef can be contaminated via ingestion of contaminated grass. The user of TERMOD II can choose from 78 different radionuclides. Additional radionuclides can be added as more data become available. Summaries of intake rates can be displayed at a local terminal or at an auxiliary high-speed printer. (author)

  6. Critical level of radionuclides pollution estimation for different soil type of Ukrainian Polessye

    International Nuclear Information System (INIS)

    Kravets, A.; Pavlenko, Y.

    1996-01-01

    The successive development and adaptation of general algorithm of calculation of doses from intake 137 Cs and 90 Sr as a function of pollution level and a type of soil as a source of the human trophycal chains and its use in solution of reverse problem, namely- estimation of the critical level of radionuclides pollution for the main type of soil of Ukrainian Polessye has been proposed. Calculation was realized as a combination of dynamic model of migration of radionuclides in soil and spreadsheet form with Quattro Pro, version 4.0. (author)

  7. Personnel dosimetry in internal radiation exposure by excretory radionuclide measurement

    International Nuclear Information System (INIS)

    Balonov, M.I.; Bruk, G.Ya.; Korelina, N.F.; Likhtarev, I.A.; Repin, V.S.

    1986-01-01

    The collaboration with the SAAS resulted in the development of a mathematical method to calculate radiation doses in human tissues attributed to inhaled radionuclides concerning their retention dynamics in the respiratory system and their uptake into the blood as well as the metabolic pathways in the organs. 'Sanep-stations' and radiation protection service elaborated nomograms for the determination of the commitment doses in the critical organs based on the radionuclide content of a 24-hours urinalysis without intermediate calculations. Recommendations for the use of the method and the nomograms for various radionuclides (solubility classes D and N with MAAD of 1 and 10 μm) are given in the methodological document: 'Indirect dosimetry of inhaled radionuclides in workers'. A calculation method for the annual dose of internal irradiation in tritium workers is also cited

  8. Statistical analysis of fallout radionuclides transfer to paddy-field rice

    International Nuclear Information System (INIS)

    Takahashi, T.; Morisawa, S.; Inoue, Y.

    1996-01-01

    Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

  9. Assessment of SRS radiological liquid and airborne contaminants and pathways

    International Nuclear Information System (INIS)

    Jannik, G.T.

    1997-04-01

    This report compiles and documents the radiological critical-contaminant/critical-pathway analysis performed for SRS. The analysis covers radiological releases to the atmosphere and to surface water, which are the principal media that carry contaminants off site. During routine operations at SRS, limited amounts of radionuclides are released to the environment through atmospheric and/or liquid pathways. These releases potentially result in exposure to offsite people. Though the groundwater beneath an estimated 5 to 10 percent of SRS has been contaminated by radionuclides, there is no evidence that groundwater contaminated with these constituents has migrated offsite (Arnett, 1996). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people

  10. Long-Term Assessment of Critical Radionuclides and Associated Environmental Media at the Savannah River Site - 13038

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, G.T.; Baker, R.A.; Lee, P.L. [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Eddy, T.P.; Blount, G.C. [Savannah River Nuclear Solutions, Savannah River Site, Aiken, SC 29808 (United States); Whitney, G.R. [US Department of Energy, Savannah River Operations, Aiken, SC 29808 (United States)

    2013-07-01

    During the operational history of the Savannah River Site (SRS), many different radionuclides have been released from site facilities. However, only a relatively small number of the released radionuclides have been significant contributors to doses and risks to the public. At SRS dose and risk assessments indicate tritium oxide in air and surface water, and Cs-137 in fish and deer have been, and continue to be, the critical radionuclides and pathways. In this assessment, statistical analyses of the long-term trends of tritium oxide in atmospheric and surface water releases and Cs-137 concentrations in fish and deer are provided. Correlations also are provided with 1) operational changes and improvements, 2) geopolitical events (Cold War cessation), and 3) recent environmental remediation projects and decommissioning of excess facilities. For example, environmental remediation of the F- and H-Area Seepage Basins and the Solid Waste Disposal Facility have resulted in a measurable impact on the tritium oxide flux to the onsite Fourmile Branch stream. Airborne releases of tritium oxide have been greatly affected by operational improvements and the end of the Cold War in 1991. However, the effects of SRS environmental remediation activities and ongoing tritium operations on tritium concentrations in the environment are measurable and documented in this assessment. Controlled hunts of deer and feral hogs are conducted at SRS for approximately six weeks each year. Before any harvested animal is released to a hunter, SRS personnel perform a field analysis for Cs-137 concentrations to ensure the Hunter's dose does not exceed the SRS administrative game limit of 0.22 milli-sievert (22 mrem). However, most of the Cs-137 found in SRS onsite deer is not from site operations but is from nuclear weapons testing fallout from the 1950's and early 1960's. This legacy source term is trended in the SRS deer, and an assessment of the 'effective' half-life of Cs

  11. Metabolism of radionuclides in domestic animals

    International Nuclear Information System (INIS)

    Wirth, E.; Leising, C.

    1986-01-01

    The reactor accident at Chernobyl has shown that shortly after the contamination of the environment radionuclides can be found in animal products. The main contamination pathways of domestic animas are: uptake of radionuclides by foodstuffs; uptake of radionuclides by contaminated drinking water; uptake of radionuclides by inhalation; uptake of radionuclides through skin; uptake of radionuclides by ingestion of soil particles. Generally the uptake of radionuclides by food is the dominant exposure pathway. In rare cases the inhalation of radionuclides or the uptake by drinking water may be of importance. The metabolism of incorporated radionuclides is comparable to the respective metabolism of essential mass or trace elements or heavy metals. Radioisotopes of essential elements are for instance iron 55, manganese 54, cobalt 58 and cobalt 60. Other elements are typical antagonists to essential elements, e.g. strontium 90 is an antagonist to calcium or cesium 137 to potassium. Lead 210 and plutonium 239 behave similarly as heavy metals. Generally the knowledge of the metabolism of trace and mass elements, of antagonistic and synergistic elements and heavy metals can be applied to these radionuclides

  12. Link 'soil-plant' as critical in formation committed doses from uptake of long-lived radionuclides

    International Nuclear Information System (INIS)

    Kravetz, A. P.; Pavlenko, Y. A.; Grodzinsky, D. M.

    1994-01-01

    General algorithm of calculation dose from intake 137 Cs and 90 Sr depending upon level of pollution and agrochemical type of soil where trophycal chains to begin with, have been proposed. This methods consider link 'soil → plant' as critical in formation of doses from the intake long-lived radionuclides. Calculation of committed dose as function of type of soil and level of radionuclide pollution have been realized for seven main soil types of the White Russian and Ukrainian Wooded district. (author)

  13. Link 'soil-plant' as critical in formation committed doses from uptake of long-lived radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Kravetz, A P; Pavlenko, Y A; Grodzinsky, D M [Institute of Cell Biology and Genetic Engineering AS Vasilcovsky st 31/17, Kiev 252022 (Ukraine)

    1994-11-01

    General algorithm of calculation dose from intake {sup 137}Cs and {sup 90}Sr depending upon level of pollution and agrochemical type of soil where trophycal chains to begin with, have been proposed. This methods consider link 'soil {yields} plant' as critical in formation of doses from the intake long-lived radionuclides. Calculation of committed dose as function of type of soil and level of radionuclide pollution have been realized for seven main soil types of the White Russian and Ukrainian Wooded district. (author)

  14. 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)

  15. 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)

  16. RAMM: a system of computer programs for radionuclide pathway analysis calculations

    International Nuclear Information System (INIS)

    Lyon, R.B.

    1976-09-01

    A generalized system of computer programs, designated RAMM (Radioactive Materials Management) system, has been developed to assist in the analysis of the movement of radionuclides through the environment to man. RAMM incorporates the GASP IV continuous/discrete simulation system. A nodal approach is used whereby the system to be analyzed is split up into parts small enough that the distribution of nuclides within the node may be taken to be homogeneous. Pathways are defined between nodes, and appropriate transfer coefficients are input or generated. Output includes the time dependent contents of the nodes and dose rates, integrated doses and dose commitments of selected nodes. (author)

  17. 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.

  18. Radionuclide fixation mechanisms in rocks

    International Nuclear Information System (INIS)

    Nakashima, S.

    1991-01-01

    In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

  19. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...... using insulin signalling as a model system....

  20. Idaho radionuclide exposure study: Literature review

    International Nuclear Information System (INIS)

    Baker, E.G.; Freeman, H.D.; Hartley, J.N.

    1987-10-01

    Phosphate ores contain elevated levels of natural radioactivity, some of which is released to the environment during processing or use of solid byproducts. The effect of radionuclides from Idaho phosphate processing operations on the local communities has been the subject of much research and study. The literature is reviewed in this report. Two primary radionuclide pathways to the environment have been studied in detail: (1) airborne release of volatile radionuclides, primarily 210 Po, from calciner stacks at the two elemental phosphorus plants; and (2) use of byproduct slag as an aggregate for construction in Soda Springs and Pocatello. Despite the research, there is still no clear understanding of the population dose from radionuclide emissions, effluents, and solid wastes from phosphate processing plants. Two other potential radionuclide pathways to the environment have been identified: radon exhalation from phosphogypsum and ore piles and contamination of surface and ground waters. Recommendations on further study needed to develop a data base for a complete risk assssment are given in the report

  1. Evaluation of radionuclide releases from underground waste repositories using the method of status vectors

    International Nuclear Information System (INIS)

    Zappe, D.

    1983-01-01

    For safety analyses of underground repositories for radioactive wastes various possible release scenarios have to be defind and anticipated consequences to be calculated and compared. Normally only the main exposure pathways (i.e. the critical pathways) of the radionuclides disposed of in the repository are calculated using deterministic methods and varying the parameters. It is proposed to evaluate all the individual pathways including those differing considerably from the critical pathway by forming weighted averages of their consequences. This offers the possibility of including, without any restriction, in the evaluation of the repository the various possible events and processes that influence the function of barriers for the retention of radionuclides. Various states (scenarios) of a repository in a salt formation, which might occur in the course of time have been used as an example. The consequences related to these states and the probabilities of their occurrence or the scenario weights form the components of 'status vectors'. For low- and intermediate-level wastes the overall consequences obtained from these calculations are negligibly small, for high-level wastes they are about 3 x 10 - 5 Sv a - 1 /GW a. These values are reached if at least a part of the barriers is effective. Variations of the weighting factors for the states and their influence on the overall consequences are given. (author)

  2. PATHWAY: a dynamic foodchain model to predict radionuclide ingestion after fallout deposition. Final report, September 17, 1979-December 31, 1985

    International Nuclear Information System (INIS)

    Whicker, F.W.; Kirchner, T.B.

    1986-01-01

    This paper describes the structure and basis for parameter values of a computerized foodchain transport model for radionuclides. The model, called ''PATHWAY,'' estimates the time-integrated intake by humans of twenty radionuclides after a single deposition of radioactive material from the atmosphere to the landscape. The model solves a set of differential equations to estimate the inventories and concentrations of radionuclides in three soil layers and numerous types of vegetation, animal tissues and animal products as a function of time following a deposition event. Dynamic processes considered in the model include foliar interception, weathering and absorption; plant growth, uptake, harvest and senescence; soil resuspension, percolation, leaching and tillage; radioactive decay; livestock ingestion, absorption, excretion; and etc. An age- and sex-specific human diet is embodied in the model to permit calculation of time-dependent radionuclide ingestion rates, which are then numerically integrated. 3 figs., 10 tabs

  3. 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

  4. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Baes, C.F. III.

    1987-01-01

    The uncertainty regarding radionuclide distributions among Remedial Action Program (RAP) sites and long-term decommissioning and closure options for these sites requires a flexible approach capable of handling different levels of contamination, dose limits, and closure scenarios. We identified a commercially available pathway analysis model, DECOM, which had been used previously in support of remedial activities involving contaminated soil at the Savannah River Plant. The DECOM computer code, which estimates concentrations of radionuclides uniformly distributed in soil that correspond to an annual effective dose equivalent, is written in BASIC and runs on an IBM PC or compatible microcomputer. We obtained the latest version of DECOM and modified it to make it more user friendly and applicable to the Oak Ridge National Laboratory (ORNL) RAP. Some modifications involved changes in default parameters or changes in models based on approaches used by the EPA in regulating remedial actions for hazardous substances. We created a version of DECOM as a LOTUS spreadsheet, using the same models as the BASIC version of DECOM. We discuss the specific modeling approaches taken, the regulatory framework that guided our efforts, the strengths and limitations of each approach, and areas for improvement. We also demonstrate how the LOTUS version of DECOM can be applied to specific problems that may be encountered during ORNL RAP activities. 18 refs., 2 figs., 3 tabs

  5. Decreasing medical complications for total knee arthroplasty: Effect of Critical Pathways on Outcomes

    Directory of Open Access Journals (Sweden)

    Solomon Daniel H

    2010-07-01

    Full Text Available Abstract Background Studies on critical pathway use have demonstrated decreased length of stay and cost without compromise in quality of care. However, pathway effectiveness is difficult to determine given methodological flaws, such as small or single center cohorts. We studied the effect of critical pathways on total knee replacement outcomes in a large population-based study. Methods We identified hospitals in four US states that performed total knee replacements. We sent a questionnaire to surgical administrators in these hospitals including items about critical pathway use and hospital characteristics potentially related to outcomes. Patient data were obtained from Medicare claims, including demographics, comorbidities, 90-day postoperative complications and length of hospital stay. The principal outcome measure was the risk of having one or more postoperative complications. Results Two hundred ninety five hospitals (73% responded to the questionnaire, with 201 reporting the use of critical pathways. 9,157 Medicare beneficiaries underwent TKR in these hospitals with a mean age of 74 years (± 5.8. After adjusting for both patient and hospital related variables, patients in hospitals with pathways were 32% less likely to have a postoperative complication compared to patients in hospitals without pathways (OR 0.68, 95% CI 0.50-0.92. Patients managed on a critical pathway had an average length of stay 0.5 days (95% CI 0.3-0.6 shorter than patients not managed on a pathway. Conclusion Medicare patients undergoing total knee replacement surgery in hospitals that used critical pathways had fewer postoperative complications than patients in hospitals without pathways, even after adjusting for patient and hospital related factors. This study has helped to establish that critical pathway use is associated with lower rates of postoperative mortality and complications following total knee replacement after adjusting for measured variables.

  6. Limitation of radioactive discharges from NPP based on radionuclide specific monitoring

    International Nuclear Information System (INIS)

    Bucina, I.; Malatova, I.; Vidlakova, J.

    1998-01-01

    Monitoring of gaseous and liquid discharges from nuclear power plants based on particulate-iodine-gas measurements and gross beta or gamma plus tritium measurements is being improved by performing radionuclide specific measurements using semiconductor gamma and beta spectrometers and radiochemical methods. A new concept of regulatory effluent limits is being developed. The activities of all the relevant radionuclides discharged during a years, multiplied by the appropriate Sv/Bq conversion coefficient based on a standard multi-pathway model, are summed up, and the effective dose is compared with the new limit. Such limits should be laid down as the per capita collective commitment effective dose in the plant surroundings for atmospheric discharges, and as the committed effective dose to a critical group member for the hydrospheric releases

  7. Incorporation of additional radionuclides and the external exposure pathway into the BECAMP [Basic Environmental Compliance and Monitoring Program] radiological assessment model

    International Nuclear Information System (INIS)

    Ng, Yook C.; Rodean, H.C.; Anspaugh, L.R.

    1988-11-01

    The Nevada Applied Ecology Group (NAEG) Model of transport and dose for transuranic radionuclides was modified and expanded for the analysis of radionuclides other than pure alpha-emitters. Doses from internal and external exposures were estimated for the inventories and soil distributions of the individual radionuclides quantified in Areas 2 and 4 of the Nevada Test Site (NTS). We found that the dose equivalents via inhalation to liver, lungs, bone marrow, and bone surface from the plutonium isotopes and 241 Am, those via ingestion to bone marrow and bone surfaces from 90 Sr, and those via ingestion to all the target organs from 137 Cs were the highest from internal exposures. The effective dose equivalents from 137 Cs, 152 Eu, and 154 Eu were the highest from the external exposures. The 60 Co, 152 Eu, 154 Eu, and 155 Eu dose estimates for external exposures greatly exceeded those for internal exposures. The 60 Co, 90 Sr, and 137 Cs dose equivalents from internal exposures were underestimated due to the adoption of some of the foodchain parameter values originally selected for 239 Pu. Nonetheless, the ingestion pathway contributed significantly to the dose estimates for 90 Sr and 137 Cs, but contributed very much less than external exposures to the dose estimates for 60 Co. Therefore, the use of more appropriate values would not alter the identification of important radionuclides, pathways, target organs, and exposure modes in this analysis. 19 refs., 13 figs., 12 tabs

  8. Radionuclide partitioning in environmental systems: a critical analysis

    International Nuclear Information System (INIS)

    Cremers, A.; Maes, A.

    1986-01-01

    A survey is given of some of the important processes involved in the solid-liquid distribution behaviour of radionuclides in both well-defined adsorbents and multicomponent natural systems. The thermodynamic significance of distribution coefficients is analyzed and the various parameters affecting partition behaviour are discussed in relation to possible retention mechanisms. Attention is being given to factors such as solid/liquid ratio, pH-Eh, reversibility, liquid phase composition and speciation effects. Various processes are discussed such as ion exchange and complex formation involving clays, oxides, humic acids. It is shown that, only in rare cases, Ksub(D) values can be rationalized in terms of process mechanistics. In addition, it is indicated that, in general, radionuclide distribution coefficients cannot be considered as constants unless the conditions are restricted to very small loading intervals. It is furthermore suggested that, in order to produce meaningful data on radionuclide partitioning behaviour, efforts should be made to operate under conditions which are representative for the 'in situ' situation. (author)

  9. [Ranking of radionuclides and pathways according to their contribution to the dose burden to the population resulting from NPP releases].

    Science.gov (United States)

    Spiridonov, S I; Karpenko, E I; Sharpan, L A

    2013-01-01

    Approaches are described towards estimating the consequences of radioactive contamination of ecosystems by nuclear fuel cycle enterprises with the rationale for the optimal specification level for nuclear power plants (NPP) operating in the normal mode. Calculations are made based on the initial data of the IAEA project, INPRO ENV, dealing with the ranking of radionuclides escaping to the environment from the operating NPPs. Influence of various factors on rankings of radionuclides and pathways of public exposure is demon- strated. An important factor is the controlled radionuclide composition of atmospheric NPP releases. It has been found that variation in the dose coefficients for some radionuclides leads to significant changes not only in the ranking results but also in the estimates of total dose burdens. Invariability is shown of the estimation concerning the greatest contribution of the peroral route to the population dose of irradiation in the situation considered. A conclusion was drawn on the need of taking into consideration uncertainties of different factors when comparing effects on the environment from enterprises of conventional and innovative nuclear fuel cycles.

  10. Transport of radionuclides in the biosphere

    International Nuclear Information System (INIS)

    Bundi, A.

    1983-10-01

    The dispersion of radionuclides in the biosphere and their uptake by man via various nutritional pathways is studied using a compartment model. The sample environment is the area of the lower Limmat and Aare valleys. General considerations of the compartmental description of the biosphere are made. The problem of the description of surface features, in particular soil, sediment and water, is studied in detail using the code BIOPATH. This study is intended to be an example of how a model of the biosphere could be constructed. It is shown that this is a reasonable model to calculate the spreading of radionuclides in the biosphere and that it indicates the relative significance of individual compartments, pathways and radionuclides. Calculated values of dose committment, however, should not be used as reference data for safety analyses. (Auth.)

  11. Biosphere Dose Conversion Factors for Reasonably Maximally Exposed Individual and Average Member of Critical Group

    International Nuclear Information System (INIS)

    K. Montague

    2000-01-01

    The purpose of this calculation is to develop additional Biosphere Dose Conversion Factors (BDCFs) for a reasonably maximally exposed individual (RMEI) for the periods 10,000 years and 1,000,000 years after the repository closure. In addition, Biosphere Dose Conversion Factors for the average member of a critical group are calculated for those additional radionuclides postulated to reach the environment during the period after 10,000 years and up to 1,000,000 years. After the permanent closure of the repository, the engineered systems within the repository will eventually lose their abilities to contain radionuclide inventory, and the radionuclides will migrate through the geosphere and eventually enter the local water table moving toward inhabited areas. The primary release scenario is a groundwater well used for drinking water supply and irrigation, and this calculation takes these postulated releases and follows them through various pathways until they result in a dose to either a member of critical group or a reasonably maximally exposed individual. The pathways considered in this calculation include inhalation, ingestion, and direct exposure

  12. Release of airborne radionuclides from Olympic Dam operations and exposure assessment for members of the public

    International Nuclear Information System (INIS)

    Harris, F.F.; Chandler, W.P.

    1992-01-01

    Olympic Dam Operations, a copper, uranium, silver and gold producing project, is situated in a semi-arid area 550 km north of Adelaide. Airborne dispersal is the major transport pathway of operation-related radionuclides to members of the public, and as such has become the focus of a major environmental monitoring program. Major emissions consist of radon and its associated daughters and radionuclides in dust that originate from mine, metallurgical plant, ore and mullock stockpiles and the tailings retention system. Dispersion modelling and measured ground level concentrations have been utilised to calculate the effective dose equivalent for three critical groups. All critical groups exposures are less than 0.2 mSv by the most conservative calculation and are well below the legislative limit of 1 mSv applicable to members of the public. 12 refs., 5 gabs., 12 figs

  13. Selection of critical group in relation to the release of radionuclides from nuclear spent fuel reprocessing plant

    International Nuclear Information System (INIS)

    Ohmomo, Y.

    1980-01-01

    In respect of internal radiation due to the coastal release of radionuclides, survey on marine food consumption is most useful for the selection of critical group. Species of marine organisms they usually eat is fully over 100 in the coastal area of Ibaraki prefecture where the fuel reprocessing plant is located. Though it gives only a spot datum, one day's consumption survey a season is of convenience to obtain cooperation from housewives and is of use to pick up critical organisms and those who eat much of them. However, long-term survey is required to estimate ordinary intake of the critical foods or those who are supposed critical people. One day's consumption survey makes it easy to perform the subsequent long-term one

  14. Radionuclide transfer in terrestrial animals

    International Nuclear Information System (INIS)

    DiGregorio, D.; Kitchings, T.; Van Voris, P.

    1978-01-01

    The analysis of dispersion of radionuclides in terrestrial food chains, generally, is a series of equations identifying the fractional input and outflow rates from trophic level to trophic level. Data that are prerequisite inputs for these food chain transport models include: (1) identification of specific transport pathway, (2) assimilation at each pathway link, and (3) the turnover rate or retention function by successive receptor species in the appropriate food chain. In this report, assimilation coefficients, biological half-lives, and excretion rates for a wide variety of vertebrate and invertebrate species and radionuclides have been compiled from an extensive search of the available literature. Using the information accumulated from the literature, correlations of nuclide metabolism and body weight are also discussed. (author)

  15. Critical pathways of change in fruit export regions at desert margin (Chile)

    DEFF Research Database (Denmark)

    Frederiksen, Peter

    The purpose is to elucidate how critical pathways function in a fruit export region at the desert margin in Chile. The region was investigated at the system level as an open land system with managed fruit plantations in a geographically complex valley. Data collection procedures included total...... change changed pathways. Pathways resulted from a combination of global value chains, the adoption of innovations, past climate change, and regional conditions at different scales. Main pathways of change were upgrade and downgrade of the fruit export region and irrigation systems, whereas the breaking...... areas and not in others. The probable future is expected to be increased separation of intraregional pathways and a more imbalanced region. The conclusion is that openness is the main property responsible for critical pathways of change in the region....

  16. Effects of radionuclide decay on waste glass behavior: A critical review

    International Nuclear Information System (INIS)

    Wronkiewicz, D.J.

    1993-12-01

    This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

  17. Application of nuclear analysis technique to determine radionuclide contents in critical food stuff

    International Nuclear Information System (INIS)

    Sri Murniasih; Sukirno; Agus Taftazani

    2010-01-01

    Rice, cassava, grist, corn and salt are Indonesian critical food stuff. The analysis of nature radionuclide in rice, cassava, grist, corn and salt measurements were carried out by gamma spectrometry with Germanium Lithium (GeLi) detector equipped by MESTROTM software and Multi Channel Analyzer (MCA) to analysis radionuclide and gamma gross. Analysis beta gross have been done using Low Background Counter (LBC) with Geiger Muller (GM) detector and Analog Digital Converter (ADC). Activity of K-40 on all samples range from 28.40 ± 2.06 to 4.22 ± 1.67 mBq/g; Th-232 range from 0.92 ± 0.57 to 6.63 ± 0.98 mBq/g; Pb-212 range from 0.38 ± 0.18 to 0.81 ± 0.10 mBq/g; Pb-214 range from 1.92 ± 1.28 - 5.17 ± 0.14 mBq/g. While beta gross and gamma gross activities range from 0.12 ± 0.09 to 0.31 ± 0.13 mBq/g and 101.73 ± 13.35 to 199.81 ± 9.21 mBq/g. Comparing with reference data from various countries, it can be concluded that radionuclide activity content in all of rice, cassava, grist, corn and salt samples doesn't difference significantly so that they are safe to be consumed. Using statistic test of ANOVA (α = 0.05) method, it found that the difference of sample has influence significant on the activity of TI-208, Pb-212, Pb-214 , gross beta and gamma gross radioactivity while on K-40 there is no significant influence on sample difference. (author)

  18. Virtual Institute of Microbial Stress and Survival: Deduction of Stress Response Pathways in Metal and Radionuclide Reducing Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-04-17

    The projects application goals are to: (1) To understand bacterial stress-response to the unique stressors in metal/radionuclide contamination sites; (2) To turn this understanding into a quantitative, data-driven model for exploring policies for natural and biostimulatory bioremediation; (3) To implement proposed policies in the field and compare results to model predictions; and (4) Close the experimental/computation cycle by using discrepancies between models and predictions to drive new measurements and construction of new models. The projects science goals are to: (1) Compare physiological and molecular response of three target microorganisms to environmental perturbation; (2) Deduce the underlying regulatory pathways that control these responses through analysis of phenotype, functional genomic, and molecular interaction data; (3) Use differences in the cellular responses among the target organisms to understand niche specific adaptations of the stress and metal reduction pathways; (4) From this analysis derive an understanding of the mechanisms of pathway evolution in the environment; and (5) Ultimately, derive dynamical models for the control of these pathways to predict how natural stimulation can optimize growth and metal reduction efficiency at field sites.

  19. Radionuclide migration pathways analysis for the Oak Ridge Central Waste Disposal Facility on the West Chestnut Ridge site

    International Nuclear Information System (INIS)

    Pin, F.G.; Witherspoon, J.P.; Lee, D.W.; Cannon, J.B.; Ketelle, R.H.

    1984-10-01

    A dose-to-man pathways analysis is performed for disposal of low-level radioactive waste at the Central Waste Disposal Facility on the West Chestnut Ridge Site. Both shallow land burial (trench) and aboveground (tumulus) disposal methods are considered. The waste volumes, characteristics, and radionuclide concentrations are those of waste streams anticipated from the Oak Ridge National Laboratory, the Y-12 Plant, and the Oak Ridge Gaseous Diffusion Plant. The site capacity for the waste streams is determined on the basis of the pathways analysis. The exposure pathways examined include (1) migration and transport of leachate from the waste disposal units to the Clinch River (via the groundwater medium for trench disposal and Ish Creek for tumulus disposal) and (2) those potentially associated with inadvertent intrusion following a 100-year period of institutional control: an individual resides on the site, inhales suspended particles of contaminated dust, ingests vegetables grown on the plot, consumes contaminated water from either an on-site well or from a nearby surface stream, and receives direct exposure from the contaminated soil. It is found that either disposal method would provide effective containment and isolation for the anticipated waste inventory. However, the proposed trench disposal method would provide more effective containment than tumuli because of sorption of some radionuclides in the soil. Persons outside the site boundary would receive radiation doses well below regulatory limits if they were to ingest water from the Clinch River. An inadvertent intruder could receive doses that approach regulatory limits; however, the likelihood of such intrusions and subsequent exposures is remote. 33 references, 31 figures, 28 tables

  20. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    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. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  1. 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

  2. Studies on distribution coefficient (Kd) of naturally occurring radionuclides in geological matrices

    International Nuclear Information System (INIS)

    Pandit, G.G.

    2014-01-01

    Accurate prediction of fate and transport of toxic and radioactive metals in the subsurface of uranium tailing pond sites is critical to the assessment of environmental impact and to the development of effective remediation technologies. The mobility of radionuclides and toxic metals is enhanced by acidification of tailings due to sulphide oxidation catalysed by microbial activity. Due to infiltration of water, there is a possibility of leaching of these radionuclides and toxic metals from the tailings pond to the ground water. Sorption onto mineral surfaces is an important mechanism for reducing radionuclide concentrations along ground water flow paths and retarding radionuclide migration to the accessible environment. Reactive transport of ground water contaminants often assume that the reaction governing the retardation of a particular contaminant or radionuclide can be described by simple partitioning constant, K d . This constant is assumed to account for all the reversible sorption processes affecting transport of the contaminant. Experimental determination of site-specific K d values is absolutely essential for the accurate estimation of reactive transport of these contaminants. The results of such studies would be helpful to model migration of these pollutants and to estimate the radiation dose to members of the public through groundwater drinking pathway at different distances from the tailings pond. In the present study it is clearly observed that K d values of most of the radionuclides are strongly dependent on different soil and ground water parameters. The relationships generated between distribution coefficient values of different radionuclides and different soil and ground water parameters can be used to generate look up table. And these relationships can also be used for the prediction of K d values of different radionuclides by using the different physico-chemical parameters of soil and ground water of the particular location

  3. MARFA user's manual: Migration analysis of radionuclides in the far field

    International Nuclear Information System (INIS)

    Painter, S.; Mancillas, J.

    2013-12-01

    The computer code Migration Analysis of Radionuclides in the Far Field (MARFA) uses a particle-based Monte Carlo method to simulate the transport of radionuclides in a sparsely fractured geological medium. The algorithm uses non-interacting particles to represent packets of radionuclide mass. These particles are moved through the system according to rules that mimic the underlying physical transport and retention processes. The physical processes represented in MARFA include advection, longitudinal dispersion, Fickian diffusion into an infinite or finite rock matrix, equilibrium sorption, decay, and in-growth. Because the algorithm uses non-interacting particles, the transport and retention processes are limited to those that depend linearly on radionuclide concentration. Multiple non-branching decay chains of arbitrary length are supported, as is full heterogeneity in the transport and retention properties. Two variants of the code are provided. These two versions differ in how particles are routed through the computational domain. In MARFA 3.2.3, transport is assumed to occur along a set of trajectories or pathways that originate at radionuclide source locations. The trajectories are intended to represent the movement of hypothetical, advectively transported groundwater tracers and are typically calculated by pathline tracing in a discrete fracture network flow code. The groundwater speed and retention properties along each pathway may change in time, but the pathway trajectories are fixed. MARFA 3.3.1 allows the transport effects of changing flow directions to be represented by abandoning the fixed pathways and performing node routing within MARFA. (orig.)

  4. 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.

  5. Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

    Science.gov (United States)

    Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

  6. The fate and importance of radionuclides produced in nuclear events

    Energy Technology Data Exchange (ETDEWEB)

    Shore, B; Anspaugh, L; Chertok, R; Gofman, J; Harrison, F; Heft, R; Koranda, J; Ng, Y; Phelps, P; Potter, G; Tamplin, A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1969-07-01

    Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

  7. The fate and importance of radionuclides produced in nuclear events

    International Nuclear Information System (INIS)

    Shore, B.; Anspaugh, L.; Chertok, R.; Gofman, J.; Harrison, F.; Heft, R.; Koranda, J.; Ng, Y.; Phelps, P.; Potter, G.; Tamplin, A.

    1969-01-01

    Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

  8. Critical success factors in implementing clinical pathways/case management.

    Science.gov (United States)

    Choo, J

    2001-07-01

    With the advent of casemix reimbursement implementation, rapid technological changes, an ageing population and changing consumer behaviour, the Singapore health care industry is faced with the impetus to provide a cost-effective and efficient care delivery system. One ubiquitous tool used is the establishment of a clinical pathway/case management programme within the hospital. As the concept of clinical pathway for patient care is a relatively new concept in Singapore, several critical factors must be considered to ensure successful implementation of clinical pathway/case management programme. One key success factor lies in continued clinician support and acceptance. Other factors include top management leadership and support and a dedicated team of case managers, nurses and paramedical professionals.

  9. Radionuclide Retention in Concrete Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    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 waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form 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 waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  10. Critical look at studies of radionuclide migration in fractured granite cores

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.; Failor, R.

    1983-05-01

    A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of /sup 85/Sr, /sup 95m/Tc, and /sup 137/Cs relative to /sup 3/H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems.

  11. Critical look at studies of radionuclide migration in fractured granite cores

    International Nuclear Information System (INIS)

    Isherwood, D.; Failor, R.

    1983-05-01

    A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of 85 Sr, /sup 95m/Tc, and 137 Cs relative to 3 H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems

  12. Design and validation of a critical pathway for hospital management of patients with severe traumatic brain injury.

    Science.gov (United States)

    Espinosa-Aguilar, Amilcar; Reyes-Morales, Hortensia; Huerta-Posada, Carlos E; de León, Itzcoatl Limón-Pérez; López-López, Fernando; Mejía-Hernández, Margarita; Mondragón-Martínez, María A; Calderón-Téllez, Ligia M; Amezcua-Cuevas, Rosa L; Rebollar-González, Jorge A

    2008-05-01

    Critical pathways for the management of patients with severe traumatic brain injury (STBI) may contribute to reducing the incidence of hospital complications, length of hospitalization stay, and cost of care. Such pathways have previously been developed for departments with significant resource availability. In Mexico, STBI is the most important cause of complications and length of stay in neurotrauma services at public hospitals. Although current treatment is designed basically in accordance with the Brain Trauma Foundation guidelines, shortfalls in the availability of local resources make it difficult to comply with these standards, and no critical pathway is available that accords with the resources of public hospitals. The purpose of the present study was to design and to validate a critical pathway for managing STBI patients that would be suitable for implementation in neurotrauma departments of middle-income level countries. The study comprised two phases: design (through literature review and design plan) and validation (content, construct, and appearance) of the critical pathway. The validated critical pathway for managing STBI patients entails four sequential subprocesses summarizing the hospital's care procedures, and includes three components: (1) nodes and criteria (in some cases, indicators are also included); (2) health team members in charge of the patient; (3) maximum estimated time for compliance with recommendations. This validated critical pathway is based on the current scientific evidence and accords with the availability of resources of middle-income countries.

  13. Approaches to modelling radionuclide transfer in agricultural systems

    International Nuclear Information System (INIS)

    Mitchell, N. G.

    1995-01-01

    Radiological dose assessment requires information describing the concentration and distribution of radionuclides in the environment. This information can be obtained from monitoring but is also evaluated with the aid of mathematical models. In such models the pathways of radionuclides from the release point to man are described in terms of transfer between compartments. The main pathways to be considered include: deposition to vegetation and soils; transfer from soil-to-plant; uptake and turnover in domestic animals; and, intake by man. The development of mathematical models for simulating transfer via these pathways depends on: an understanding of the system under study, in particular for those processes that are most important in the overall transfer to man; the availability of data to determine the structure and parameters for the model; the computing systems available; the knowledge of the user of the model; and, the application of the model. (author)

  14. Evaluation of skin and ingestion exposure pathways

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, Rosanne [Pacific Northwest Laboratory, Richland, WA (United States); Logsdon, Joe E [United States Environmental Protection Agency, Office of Radiation Programs, Washington, DC (United States)

    1989-06-01

    After a nuclear accident when there has been a release of radionuclides into the atmosphere with consequential deposition on the ground, decisions are necessary on whether protective action guides should be implemented. In order to do this, several pathways for radiation exposure must be evaluated to determine the projected dose to individuals. The objective of this study, conducted by Pacific Northwest Laboratories for the U.S. Environmental Protection Agency, is to provide background information on exposure pathways for use in the development of Protective Action Guides. The relative importance of three exposure pathways that are usually considered to be unimportant compared to other pathways expected to control relocation decisions following a nuclear power plant accident is evaluated. The three pathways are the skin dose from contact with radionuclides transferred from the ground, the skin dose from radionuclides on the ground surface, and ingestion of radionuclides transferred directly to the mouth from the hands or other contaminated surfaces. Ingestion of contaminated food is not included in this evaluation, except for situations where the food is contaminated as a result of actions by the person who consumes the food (e.g., transfer of contamination from hands to food). Estimates of skin and ingestion doses are based on a source term with a radionuclide mix predicted for an SST2-type nuclear accident in an area where the first year reference whole-body dose equivalent from whole body external exposure to gamma radiation plus the committed effective dose equivalent from inhalation of resuspended radionuclides is 1 rem. Appendixes have been included to allow the reader to examine dose factor calculations, source-term data, and quantification of contact and ingestion parameters in more detail.

  15. Evaluation of skin and ingestion exposure pathways

    International Nuclear Information System (INIS)

    Aaberg, Rosanne; Logsdon, Joe E.

    1989-06-01

    After a nuclear accident when there has been a release of radionuclides into the atmosphere with consequential deposition on the ground, decisions are necessary on whether protective action guides should be implemented. In order to do this, several pathways for radiation exposure must be evaluated to determine the projected dose to individuals. The objective of this study, conducted by Pacific Northwest Laboratories for the U.S. Environmental Protection Agency, is to provide background information on exposure pathways for use in the development of Protective Action Guides. The relative importance of three exposure pathways that are usually considered to be unimportant compared to other pathways expected to control relocation decisions following a nuclear power plant accident is evaluated. The three pathways are the skin dose from contact with radionuclides transferred from the ground, the skin dose from radionuclides on the ground surface, and ingestion of radionuclides transferred directly to the mouth from the hands or other contaminated surfaces. Ingestion of contaminated food is not included in this evaluation, except for situations where the food is contaminated as a result of actions by the person who consumes the food (e.g., transfer of contamination from hands to food). Estimates of skin and ingestion doses are based on a source term with a radionuclide mix predicted for an SST2-type nuclear accident in an area where the first year reference whole-body dose equivalent from whole body external exposure to gamma radiation plus the committed effective dose equivalent from inhalation of resuspended radionuclides is 1 rem. Appendixes have been included to allow the reader to examine dose factor calculations, source-term data, and quantification of contact and ingestion parameters in more detail

  16. Report on the Oak Ridge sewage sludge land-farming experience. Part II. Pathways analysis

    International Nuclear Information System (INIS)

    Oakes, T.W.; Ohnesorge, W.F.; Daniels, K.L.; Braunstein, H.M.; Kitchings, J.T.; Alexander, W.A.

    1984-08-01

    The data presented in Part I was used to analyze the potential hazard to humans from the transport of radioactive material from the sludge disposal area into the surrounding environment. A number of environmental pathways were examined to determine the possible radiation dose that humans might incur if radionuclides from the disposal site were concentrated in an environmental medium other than soil. Subsequent to the data assessment, calculations were made to delineate the potential dose received from exposure to five different environmental pathways: (a) direct radiation from the field; (b) inhalation of dust emissions from the sludge disposal area; (c) ingestion of water resulting from radionuclides being leached from the soil and transported via surface runoff into Melton Hill Lake; (d) ingestion of fish caught in Melton Hill Lake; and (e) ingestion of deer meat from animals which might graze on the contaminated site. Results of analyses from these four pathways showed the total annual exposure to be 4.2 mrem to the endostial cells (critical organ) and 1.1 mrem to the total body. 5 references, 7 tables

  17. Biosphere transport of radionuclides. First modelling by using a selected example

    International Nuclear Information System (INIS)

    Bundi, A.

    1984-12-01

    The dispersion of radionuclides in the biosphere and their uptake by man via various nutritional pathways is studied using a compartment model. The sample environment is the area of the lower Limmat and Aare valleys. General considerations of the compartmental description of the biosphere are made. The problem of the description of surface features, in particular soil, sediment and water, is studied in detail using the code BIOPATH. This study is intended to be an example of how a model of the biosphere could be constructed. It is shown that this is a reasonable model to calculate the spreading of radionuclides in the biosphere and that it indicates the relative significance of individual compartments, pathways and radionuclides. Calculated values of doses to man, however, should not be used as reference data for safety analyses. (author)

  18. Radionuclide Retention in Concrete Wasteforms - FY13

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

    2013-10-15

    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. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  19. Radionuclides in the environment: Risks and opportunities

    International Nuclear Information System (INIS)

    Elzerman, A.W.

    1993-01-01

    Environmental chemistry plays a critical role in the open-quotes nuclear ageclose quotes. It makes a vital contribution to understanding of the sources, fate and effects of radionuclides in the environment, both man-made and natural. Risk assessment of radionuclides in the environment relies heavily on the tools of environmental chemistry. On the other hand, radionuclides provide unique opportunities to exploit in environmental chemistry investigations due to their well-defined sources, traceability in environmental processes, analytical sensitivities, and open-quotes built-inclose quotes radioactive decay open-quotes clocksclose quotes. In some cases naturally present radionuclides are utilized, while in others tracers are deliberately added or have already been added by the nuclear fuel cycle or nuclear testing. Several examples in each of these categories are discussed to spotlight the current status of environmental chemistry and radionuclides in the environment as an example application

  20. The speciation, stability, solubility and biodegradation of organic co-contaminant radionuclide complexes: A review

    International Nuclear Information System (INIS)

    Keith-Roach, Miranda J.

    2008-01-01

    The potential migration of radionuclides is of concern at contaminated land sites and, in the long term, waste repositories. Pathways of migration need to be characterised on a predictive level so that management decisions can be made with confidence. A pathway that is relatively poorly understood at present is radionuclide solubilisation due to complexation by organic complexing agents that are present in mixed radioactive wastes, and at radioactively contaminated land sites. Interactions of the complexing agents with radionuclides and the host environment, and the response to changes in the physicochemical conditions make their role far from simple to elucidate. In addition, chemical and biodegradation of the organic materials may be important. In this paper, key co-contaminant organics are reviewed with emphasis on their environmental fate and impact on radionuclide migration

  1. The speciation, stability, solubility and biodegradation of organic co-contaminant radionuclide complexes: A review

    Energy Technology Data Exchange (ETDEWEB)

    Keith-Roach, Miranda J. [Biogeochemistry and Environmental Analytical Chemistry Group/Consolidated Radio-isotope Facility, School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: mkeith-roach@plymouth.ac.uk

    2008-06-15

    The potential migration of radionuclides is of concern at contaminated land sites and, in the long term, waste repositories. Pathways of migration need to be characterised on a predictive level so that management decisions can be made with confidence. A pathway that is relatively poorly understood at present is radionuclide solubilisation due to complexation by organic complexing agents that are present in mixed radioactive wastes, and at radioactively contaminated land sites. Interactions of the complexing agents with radionuclides and the host environment, and the response to changes in the physicochemical conditions make their role far from simple to elucidate. In addition, chemical and biodegradation of the organic materials may be important. In this paper, key co-contaminant organics are reviewed with emphasis on their environmental fate and impact on radionuclide migration.

  2. Estimation of radionuclide ingestion: Lessons from dose reconstruction for fallout from the Nevada Test Site

    International Nuclear Information System (INIS)

    Breshears, D.D.; Whicker, F.W.; Kirchner, T.B.; Anspaugh, L.R.

    1994-01-01

    The United States conducted atmospheric testing of nuclear devices at the Nevada Test Site from 1951 through 1963. In 1979 the U.S. Department of Energy established the Off-Site Radiation Exposure Review Project to compile a data base related to health effects from nuclear testing and to reconstruct doses to public residing off of the Nevada Test Site. This project is the most comprehensive dose reconstruction project to date, and, since similar assessments are currently underway at several other locations within and outside the U.S., lessons from ORERP can be valuable. A major component of dose reconstruction is estimation of dose from radionuclide ingestion. The PATHWAY food-chain model was developed to estimate the amount of radionuclides ingested. For agricultural components of the human diet, PATHWAY predicts radionuclide concentrations and quantities ingested. To improve accuracy and model credibility, four components of model analysis were conducted: estimation of uncertainty in model predictions, estimation of sensitivity of model predictions to input parameters, and testing of model predictions against independent data (validation), and comparing predictions from PATHWAY with those from other models. These results identified strengths and weaknesses in the model and aided in establishing the confidence associated with model prediction, which is a critical component risk assessment and dose reconstruction. For fallout from the Nevada Test Site, by far, the largest internal doses were received by the thyroid. However, the predicted number of fatal cancers from ingestion dose was generally much smaller than the number predicted from external dose. The number of fatal cancers predicted from ingestion dose was also orders of magnitude below the normal projected cancer rate. Several lessons were learned during the study that are relevant to other dose reconstruction efforts

  3. RIVER-RAD, Radionuclide Transport in Surface Waters

    International Nuclear Information System (INIS)

    1996-01-01

    1 - Description of program or function: RIVER-RAD assesses the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. 2 - Method of solution: A compartmental linear transfer model is used in RIVER-RAD. The river system model in the code is divided into reaches (compartments) of equal size, each with a sediment compartment below it. The movement of radionuclides is represented by a series of transfers between the reaches, and between the water and sediment compartments of each reach. Within each reach (for both the water and sediment compartments), the radionuclides are assumed to be uniformly mixed. Upward volatilization is allowed from the water compartment, and the transfer of radionuclides between the reaches is determined by the flow rate of the river. Settling and resuspension velocities determine the transfer of absorbed radionuclides between the water and sediment compartments. Radioactive decay and decay-product buildup are incorporated into all transport calculations for all radionuclide chains specified by the user. Each nuclide may have unique input and removal rates. Volatilization and radiological decay are considered as linear rate constants in the model. 3 - Restrictions on the complexity of the problem: None noted

  4. Radionuclide fate and effects

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The studies reported here deal with the full range of contaminant behavior and fate, from the initial physicochemical factors that govern radionuclide availability in terrestrial and aquatic environments to studies of contaminant transport by biological means. By design, we focus more on the biologically and chemically mediated transport processes and food-chain pathways than on the purely physical forms of contaminant transport, such as transport by wind and water

  5. Numerical modeling of the radionuclide water pathway with HYDRUS and comparison with the IAEA model of SR 44.

    Science.gov (United States)

    Merk, Rainer

    2012-02-01

    This study depicts a theoretical experiment in which the radionuclide transport through the porous material of a landfill consisting of concrete rubble (e.g., from the decommissioning of nuclear power plants) and the subsequent migration through the vadose zone and aquifer to a model well is calculated by means of the software HYDRUS-1D (Simunek et al., 2008). The radionuclides originally contained within the rubble become dissolved due to leaching caused by infiltrated rainwater. The resulting well-water contamination (in Bq/L) is calculated numerically as a function of time and location and compared with the outcome of a simplified analytic model for the groundwater pathway published by the IAEA (2005). Identical model parameters are considered. The main objective of the present work is to evaluate the predictive capacity of the more simple IAEA model using HYDRUS-1D as a reference. For most of the radionuclides considered (e.g., ¹²⁹I, and ²³⁹Pu), results from applying the IAEA model were found to be comparable to results from the more elaborate HYDRUS modeling, provided the underlying parameter values are comparable. However, the IAEA model appears to underestimate the effects resulting from, for example, high nuclide mobility, short half-life, or short-term variations in the water infiltration. The present results indicate that the IAEA model is suited for screening calculations and general recommendation purposes. However, the analysis of a specific site should be accompanied by detailed HYDRUS computer simulations. In all models considered, the calculation outcome largely depends on the choice of the sorption parameter K(d). Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Effect of different combining patterns of radionuclides in marine organisms

    International Nuclear Information System (INIS)

    Ueda, T.; Suzuki, Y.; Nakamura, R.; Nakahara, M.

    1981-01-01

    Information on the environmental factors (level of radioactivity in sea water, salinity, temperature, etc.), the biological factors (growth stage, species of organism, etc.), and the metabolism of radionuclides in marine organisms should be taken into account so as to understand the mechanism of radioactive contamination of marine organisms. From this viewpoint, the combining of radionuclides with constituents in marine organisms was studied, indicating the differences as follows: (a) Different appearances of radioactive cobalt in the liver of the abalone due to chemical forms: From the gel filtration profiles on Sephadex it was observed that 57 Co accumulated in the liver of the abalone from sea water labelled by complexed 57 Co combines with a constituent in the liver that has a molecular weight of about 40,000. However, 60 Co taken up from sea water containing ionic 60 Co combines with other constituents in the liver. (b) Appearance of radionuclides in fish due to pathways (sea water and food): In fish liver, most 137 Cs from both sea water and food combines with only one constituent substance; the molecular weight of this substance was estimated at 1100-1300. Cobalt-60 from both sea water and food associates with two different molecular weight constituents, but 65 Zn made a considerable difference in the gel filtration profiles between sea water and food. These results indicate that the metabolism of radionuclides in marine organisms may possibly be varied by the chemical forms of radionuclides in sea water and the pathways of radionuclides. (author)

  7. Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Meck, Robert A. [U.S. Nuclear Regulatory Commission

    2008-10-01

    This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intake or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently

  8. Transient simulation and sensitivity analysis for transport of radionuclides in a saturated-unsaturated groundwater flow system

    International Nuclear Information System (INIS)

    Chen, H.H.

    1980-01-01

    Radionuclide transport by groundwater flow is an important pathway in the assessment of the environmental impact of radioactive waste disposal to the biosphere. A numerical model was developed to simulate radionuclide transport by groundwater flow and predict the radionuclide discharge rate to the biosphere. A sensitivity analysis methodology was developed to address the sensitivity of the input parameters of the radionuclide transport equation to the specified response of interest

  9. Sellafield waste radionuclides in Irish sea intertidal and salt marsh sediments.

    Science.gov (United States)

    Mackenzie, A B; Scott, R D

    1993-09-01

    Low level liquid radioactive waste discharges from the Sellafield nuclear fuel reprocessing plant in north west England had generated environmental inventories of about 3 × 10(16) Bq of(137)Cs, 6.8 × 10(14) Bq of(239,240)Pu and 8.9 × 10(14) Bq of(241)Am by 1990. Most of the(239,240)Pu and(241)Am and about 10% of the(137)Cs has been retained in a deposit of fine marine sediment close to the discharge point. The quantities of radionuclides discharged annually from Sellafield decreased by two orders of magnitude from the mid-1970s to 1990 but estimated critical group internal and external exposure decreased by less than one order of magnitude over this period. This indicates that during the period of reduced discharges, radionuclides already in the environment from previous releases continued to contribute to the critical group exposure and highlights the need to understand processes controlling the environmental distribution of the radionuclides.Redistribution of the contaminated marine sediment is potentially of major significance in this context, in particular if it results in transport of radionuclides to intertidal areas, where contact with the human population is relatively likely.A review is presented of published work relating to Sellafield waste radionuclides in Irish Sea sediments. Data on temporal and spatial trends in radionuclide concentrations and activity ratios are collated from a number of sources to show that the dominant mechanism of radionuclide supply to intertidal areas is by redistribution of the contaminated marine sediment. The implications of this mechanism of supply for trends in critical group radiation exposure are considered.

  10. Introduction [Nuclear data for the production of therapeutic radionuclides

    International Nuclear Information System (INIS)

    Qaim, S.M.

    2011-01-01

    Radioactivity plays an important role in medical science in terms of beneficial applications in both diagnosis and therapy. The former entails the introduction of a short lived radionuclide attached to a suitable pharmaceutical into the patient, and measurement of the accumulation and movement of activity from outside. This process is called emission tomography and involves the measurement of either a single low energy γ ray (i.e. single photon computed emission tomography) or coincidences between the two 511 keV photons formed in the annihilation of a positron (i.e. positron emission tomography (PET)). The major governing principle in all diagnostic studies is that the radiation dose to the patient is as low as possible. Two modalities exist in the therapeutic use of radioactivity. The first and most commonly followed procedure involves the use of external beams of electrons, X rays and γ rays from radioactive sources (e.g. 60 Co), high energy γ rays from accelerators, and hadrons (e.g. neutrons, protons and heavy ions). The second modality involves the introduction of certain radionuclides to a given part of the body (e.g. joints, organ and tumour) either mechanically or via a biochemical pathway. Mechanical introduction is called brachytherapy, whereas the biochemical pathway is known as endoradiotherapy. External radiation therapy is outside the scope of the present studies. The concerted and collaborative efforts described here deal specifically with the production and use of radionuclides. An earlier coordinated research project (CRP) of the IAEA was devoted to diagnostic radionuclides. The present effort is related to therapeutic radionuclides.

  11. Use of a simplified pathways model to improve the environmental surveillance program at the radioactive waste management complex of the Idaho National Engineering Laboratory (INEL)

    International Nuclear Information System (INIS)

    Case, M.J.; Rope, S.K.

    1985-01-01

    Systems analysis, including a simple pathways model based on first-order kinetics, is a useful way to design or improve environmental monitoring networks. This method allows investigators and administrators to consider interactions that may be occurring in the system and provides guidance in determining the need to collect data on various system components and processes. A simplified pathways model of radionuclide movement from low-level waste and transuranic waste buried at the Radioactive Waste Management Complex was developed (1) to identify critical pathways that should be monitored and (2) to identify key input parameters that need investigation by special studies. The model was modified from the Savannah River Laboratory DOSTOMAN code. Site-specific data were used in the model, if available. Physical and biological pathways include airborne and waterborne transport of surface soil, subsurface migration to the aquifer, waste container degradation, plant uptake, small mammal burrowing, and a few simplified food chain pathways. The model was run using a set of radionuclides determined to be significant in terms of relative hazard. Critical transport pathways which should be monitored were selected based on relative influence on model results. Key input parameters were identified for possible special studies by evaluating the sensitivity of model response to the parameters used to define transport pathways. A description of the approaches used and the guidance recommended to improve the environmental surveillance program are presented in this paper. 5 references, 1 figure, 2 tables

  12. Natural radionuclides in the UK marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Rollo, S F.N.; Camplin, W C; Allington, D J; Young, A K [Ministry of Agriculture, Fisheries and Food, Lowestoft (United Kingdom). Fisheries Radiobiological Lab.

    1992-01-01

    The importance of natural radionuclides giving rise to radiation exposure of man from marine consumption pathways has been known for some time. However, the extent of surveys of levels in marine biota has been limited. This paper presents new data on concentrations of natural radionuclides in fish, shellfish and seaweeds taken from coastal sampling locations in the U.K. Sampling included areas where levels due to natural sources would be predominant, but efforts were made to study potential sources of technologically enhanced discharges to seas and rivers, particularly the phosphogypsum plant at Whitehaven in Cumbria. The highest concentrations (up to 371 Bq.kg[sup -1] (wet) [sup 210]Po) were observed in winkles near Whitehaven. The general levels at sites remote from known sources were much lower. Monthly concentrations in molluscs at a single location were elevated by approximately a factor of 2 during the summer months. An assessment of the expected doses to members of the public from marine consumption pathways is made. (author).

  13. 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

  14. 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

  15. 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

  16. 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

  17. Radionuclide distribution and transport in terrestrial and aquatic ecosystems. A critical review of data

    International Nuclear Information System (INIS)

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

    1984-01-01

    These volumes present the results of a study undertaken for the Commission of the European Communities. The aim was to review available data concerning the movement of radionuclides through the environment and to recommend values of parameters for use in environmental transport models. The elements reviewed all have radioactive isotopes which could contribute significantly to the radiological impact of chronic releases of radioactivity from nuclear installations within the countries of the European community, i.e. the major activation and fission products. In dividing these elements between volumes an effort has been made to take account of the method of production of their major radioisotopes, together with their chemical similarities and environmental interactions. This volume covers the radionuclide distribution of americium and curium. The main areas which are covered include the deposition of radionuclides on plants and soils, transport in soils, uptake and translocation in plants via the roots and foliage, metabolism in domestic animals and radionuclide transfers through the main physical and biotic components of the aquatic environment. In reviewing these subject areas, account has been taken not only of the literature relating to specific radionuclides, but also of the literature relating to the stable element of which they are radioisotopes. (Auth.)

  18. Radionuclide transport modelling for a buried near surface low level radioactive waste

    International Nuclear Information System (INIS)

    Terzi, R.

    2004-01-01

    The disposal of radioactive waste, which is the last step of any radioactive waste management policy, has not yet been developed in Turkey. The existing legislation states only the discharge limits for the radioactive wastes to be discharged to the environment. The objective of this modelling study is to assist in safety assessment and selecting disposal site for gradually increasing non-nuclear radioactive wastes. This mathematical model has been developed for the environmental radiological assessment of near surface disposal sites for the low and intermediate level radioactive wastes. The model comprised of three main components: source term, geosphere transport and radiological assessment. Radiation dose for the babies (1 years age) and adults (≥17 years age) have been computed for the radionuclides Cesium 137 (Cs-137) and Strontium 90 (Sr-90), having the activity of 1.10 12 Becquerel(Bq), in radioactive waste through transport of radionuclide in liquid phase with the various pathways. The model consisted of first order ordinary differential equations was coded as a TCODE file in MATLAB program. The radiation dose to man for the realist case and low probability case have been calculated by using Runge-Kutta solution method in MATLAB programme for radionuclide transport from repository to soil layer and then to the ground water(saturated zone) through drinking water directly and consuming agricultural and animal products pathways in one year period. Also, the fatal cancer risk assessment has been made by taking into account the annual dose received by people. Various dose values for both radionuclides have been found which depended on distribution coefficient, retardation factor and dose conversion factors. The most important critical parameters on radiological safety assessment are the distribution coefficient in soil layer, seepage velocity in unsaturated zone and thickness of the unsaturated zone (soil zone). The highest radiation dose and average dose to

  19. Developments in Bioremediation of Soils and Sediments Pollutedwith Metals and Radionuclides: 2. Field Research on Bioremediation of Metals and Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.; Tabak, Henry H.

    2007-03-15

    Bioremediation of metals and radionuclides has had manyfield tests, demonstrations, and full-scale implementations in recentyears. Field research in this area has occurred for many different metalsand radionuclides using a wide array of strategies. These strategies canbe generally characterized in six major categories: biotransformation,bioaccumulation/bisorption, biodegradation of chelators, volatilization,treatment trains, and natural attenuation. For all field applicationsthere are a number of critical biogeochemical issues that most beaddressed for the successful field application. Monitoring andcharacterization parameters that are enabling to bioremediation of metalsand radionuclides are presented here. For each of the strategies a casestudy is presented to demonstrate a field application that uses thisstrategy.

  20. Preclosure probabilistic assessment of the Canadian concept for used fuel disposal focussing on key radionuclides and exposure pathways for routine emissions

    International Nuclear Information System (INIS)

    Russell, S.B.

    1996-01-01

    The Canadian Nuclear Fuel Waste Management Program was initiated in 1978 to develop a concept for safe disposal of nuclear fuel waste (intact used nuclear fuel or high-level waste from any future reprocessing of used fuel) from CANDU reactors. The concept includes the immobilization of nuclear fuel waste and emplacement of the waste in an engineered vault, deep underground in a stable rock formation within the Canadian Shield. In 1994, AECL submitted an environmental and safety assessment of the disposal concept in the form of an Environmental Impact Statement or EIS for regulatory, scientific and public reviews. Ontario Hydro's contribution to the EIS included the preclosure assessment consisting of the safety and environmental implications of the construction, operation and decommissioning (closure) of a conceptual used-fuel disposal centre (UFDC), plus transportation of used fuel from storage at reactor sites to the UFDC. In the EIS, the environmental impact from routine emissions from the UFDC during the operation phase was calculated in a deterministic mode using single-valued constants representing the geometric mean or the average value of the input parameters in the preclosure model PREAC (Preclosure Radiological Environmental Assessment Code). A qualitative estimate of the range of uncertainty associated with the preclosure model dose predictions was about an order of magnitude based on a review of the expected range of input parameter values. This paper examines the time-behaviour of the preclosure system and provides a quantitative estimate of the uncertainty, as determined through the use of probabilistic techniques, associated with the potential radiological impact from the same chronic UFDC radionuclide emissions during the preclosure phase. The individual dose to a member of the critical group assumed to be living near the UFDC has been assessed for selected key radionuclides and exposure pathways identified in the EIS. The purpose of this post

  1. Radionuclide characterization and associated dose from long-lived radionuclides in close-in fallout delivered to the marine environment at Bikini and Enewetak Atoll

    International Nuclear Information System (INIS)

    Noshkin, V. E.; Robison, W. L.

    1998-01-01

    Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the United States as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 Mt (Mt TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive fission and particle activated products, and unspent radioactive nuclear fuel that entered the aquatic environment of the atolls. Today, the sediments in the lagoons are reservoirs for 10's of TBq of the transuranics and some long-lived fission and activation products. The larger amounts of contamination are associated with fine and coarse sediment material adjacent to the locations of the high yield explosions. Radionuclides are also distributed vertically in the sediment column to various depths in all regions of the lagoons. Concentrations greater than fallout background levels are found in filtered water sampled over several decades from all locations and depths in the lagoons. This is a direct indication that the radionuclides are continuously mobilized to solution from the solid phases. Of particular importance is the fact that the long-lived radionuclides are accumulated to different levels by indigenous aquatic plants and organisms that are used as food by resident people. One might anticipate finding continuous high contamination levels in many of the edible marine organisms from the lagoons, since the radionuclides associated with the sediments are not contained and are available to the different organisms in a relatively shallow water environment. This is not the case. We estimate that the radiological dose from consumption of the edible parts of marine foods at Enewetak and Bikini is presently about 0.05% of the total 50-year integral effective dose from all other exposure pathways that include ingestion of terrestrial foods and drinking water, external exposure and inhalation. The total radiological dose from the marine pathway is dominated by

  2. Uranium and thorium decay series radionuclides in human and animal foodchains - a review

    International Nuclear Information System (INIS)

    Linsalata, P.

    1994-01-01

    Human exposures along plant and animal pathways to isotopes of U, Th, Ra, Pb, and Po are reviewed. The range and variability of intakes among human populations resulting from dietary sources are presented. Also discussed are the sources of intake among fare animals reared for consumption. Under most circumstances, the soil-plant-human pathway is the predominant route of intake for humans and livestock. Radionuclide distributions within livestock and human tissues, and the transfer factors used to model intakes along various food chain pathways an summarized. Bone is the major site of deposition in livestock and humans. Where possible, summary data and conclusions from previous reviews are considered along with some notable gaps in the data base for natural series radionuclides. 67 refs., 4 figs., 6 tabs

  3. Fate of major radionuclides in the liquid wastes released to coastal waters

    International Nuclear Information System (INIS)

    Bhat, I.S.; Verma, P.C.; Iyer, R.S.; Chandramouli, S.

    1980-01-01

    131 I, 134 Cs, 137 Cs and 60 Co have been reported as the major radionuclides in the low level liquid wastes released to coastal waters from atomic power stations. Silt absorption and desorption of the radionuclides were investigated. The exchangeability of the silt absorbed radionuclides and its dependence on particle size were also studied. More than 80% instantaneous absorpt;.on of 60 Co by suspended silt and less than 5% exchangeability of absorbed 60 Co were observed. Biological uptake of the radionuclides by the marine organisms present in sea waters was studied to evaluate radiation exposure pathways. A few benthic and crustacean organisms wnich are consumed by coastal population as fresh sea food, were observed to concentrate the radionuclides to a greater extent than other organisms. (H.K.)

  4. Understanding Radionuclide Interactions with Layered Materials

    Science.gov (United States)

    Wang, Y.

    2015-12-01

    Layered materials play an important role in nuclear waste management and environmental cleanup. Better understanding of radionuclide interactions with those materials is critical for engineering high-performance materials for various applications. This presentation will provide an overview on radionuclide interactions with two general categories of layered materials - cationic clays and anionic clays - from a perspective of nanopore confinement. Nanopores are widely present in layered materials, either as the interlayers or as inter-particle space. Nanopore confinement can significantly modify chemical reactions in those materials. This effect may cause the preferential enrichment of radionuclides in nanopores and therefore directly impact the mobility of the radionuclides. This effect also implies that conventional sorption measurements using disaggregated samples may not represent chemical conditions in actual systems. The control of material structures on ion exchange, surface complexation, and diffusion in layered materials will be systematically examined, and the related modeling approaches will be discussed. This work was performed at Sandia National Laboratories, which is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the DOE under contract DE-AC04-94AL8500.

  5. Airborne radionuclides in the proglacial environment as indicators of sources and transfers of soil material.

    Science.gov (United States)

    Łokas, Edyta; Wachniew, Przemysław; Jodłowski, Paweł; Gąsiorek, Michał

    2017-11-01

    A survey of artificial ( 137 Cs, 238 Pu, 239+240 Pu, 241 Am) and natural ( 226 Ra, 232 Th, 40 K, 210 Pb) radioactive isotopes in proglacial soils of an Arctic glacier have revealed high spatial variability of activity concentrations and inventories of the airborne radionuclides. Soil column 137 Cs inventories range from below the detection limit to nearly 120 kBq m -2 , this value significantly exceeding direct atmospheric deposition. This variability may result from the mixing of materials characterised by different contents of airborne radionuclides. The highest activity concentrations observed in the proglacial soils may result from the deposition of cryoconites, which have been shown to accumulate airborne radionuclides on the surface of glaciers. The role of cryoconites in radionuclide accumulation is supported by the concordant enrichment of the naturally occurring airborne 210 Pb in proglacial soil cores showing elevated levels of artificial radionuclides. The lithogenic radionuclides show less variability than the airborne radionuclides because their activity concentrations are controlled only by the mixing of material derived from the weathering of different parent rocks. Soil properties vary little within and between the profiles and there is no unequivocal relationship between them and the radionuclide contents. The inventories reflect the pathways and time variable inputs of soil material to particular sites of the proglacial zone. Lack of the airborne radionuclides reflects no deposition of material exposed to the atmosphere after the 1950s or its removal by erosion. Inventories above the direct atmospheric deposition indicate secondary deposition of radionuclide-bearing material. Very high inventories indicate sites where transport pathways of cryoconite material terminated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. 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

  7. Radionuclide characterization and associated dose from long-lived radionuclides in close-in fallout delivered to the marine environment at Bikini and Enewetak Atolls

    International Nuclear Information System (INIS)

    Robison, W.L.; Noshkin, V.E.

    1999-01-01

    Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the US as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 million t (million t TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive fission and particle activated products, and unspent radioactive nuclear fuel that entered the aquatic environment of the atolls. Today, the sediments in the lagoons are reservoirs for tens of TBq of the transuranics and some long-lived fission and activation products. The larger amounts of contamination are associated with fine and coarse sediment material adjacent to the locations of the high yield explosions. Radionuclides are also distributed vertically in the sediment column to various depths in all regions of the lagoons. Concentrations greater than fallout background levels are found in filtered water sampled over several decades from all locations and depths in the lagoons. This is a direct indication that the radionuclides are continuously mobilized to solution from the solid phases. Of particular importance is the fact that the long-lived radionuclides are accumulated to different levels by indigenous aquatic plants and organisms that are used as food by resident people. One might anticipate finding continuous high contamination levels in many of the edible marine organisms from the lagoons, since the radionuclides associated with the sediments are not contained and are available to the different organisms in a relatively shallow water environment. This is not the case. We estimate that the radiological dose from consumption of the edible parts of marine foods at Enewetak and Bikini is presently approximately 0.05% of the total 50-year integral effective dose from all other exposure pathways that include ingestion of terrestrial foods and drinking water, external exposure and inhalation. The total radiological dose from the marine pathway is

  8. Cleanup standards and pathways analysis methods

    International Nuclear Information System (INIS)

    Devgun, J.S.

    1993-01-01

    Remediation of a radioactively contaminated site requires that certain regulatory criteria be met before the site can be released for unrestricted future use. Since the ultimate objective of remediation is to protect the public health and safety, residual radioactivity levels remaining at a site after cleanup must be below certain preset limits or meet acceptable dose or risk criteria. Release of a decontaminated site requires proof that the radiological data obtained from the site meet the regulatory criteria for such a release. Typically release criteria consist of a composite of acceptance limits that depend on the radionuclides, the media in which they are present, and federal and local regulations. In recent years, the US Department of Energy (DOE) has developed a pathways analysis model to determine site-specific soil activity concentration guidelines for radionuclides that do not have established generic acceptance limits. The DOE pathways analysis computer code (developed by Argonne National Laboratory for the DOE) is called RESRAD (Gilbert et al. 1989). Similar efforts have been initiated by the US Nuclear Regulatory Commission (NRC) to develop and use dose-related criteria based on genetic pathways analyses rather than simplistic numerical limits on residual radioactivity. The focus of this paper is radionuclide contaminated soil. Cleanup standards are reviewed, pathways analysis methods are described, and an example is presented in which RESRAD was used to derive cleanup guidelines

  9. Factors influencing the transfer of radionuclides in agricultural food chains

    International Nuclear Information System (INIS)

    Vandecasteele, C.M.; Zeevaert, Th.; Kirchmann, R.

    1991-01-01

    The applications of nuclear energy have led and will continue to lead to routine or accidental discharges of radioactive elements into the atmospheric and/or aquatic environment resulting in the exposure of populations to ionising radiations. The radionuclides released into the atmosphere are transported downwind, dispersed by the atmospheric mixing phenomena and progressively settled by deposition processes. During the passage of the radioactive cloud, people are irradiated externally as well as internally by inhalation. After the passage of the cloud, exposure of the population continues via three main pathways: external irradiation from the radionuclides deposited on the ground, inhalation of resuspended contaminated particles and ingestion of contaminated food products. When discharged into aquatic systems, the radionuclides can be partly removed from the aqueous phase by adsorption on suspended solids and bottom sediments. As the radioactivity disperses, there is a continuing exchange between water and solid phases. The contaminated sediments deposited on the banks of rivers, lakes and coastal area lead to external irradiation of people spending time at these sites. The residual activity in water exposes man internally through the ingestion of drinking water and food products, contaminated by irrigation of vegetation and ingestion of water by livestock. Among the various exposure pathways, the main route of entry of fission products and most other artificial radionuclides into man has been identified as uptake from the diet. Since agricultural products constitute the basic diet of most populations, the fate and behavior of radionuclides in agricultural ecosystems are of primary importance when assessing the exposure risk of man from environmental releases of radioactivity. 69 refs., 4 figs

  10. Soil-plant-relationships and ecological forecast of human internal doses from long-lived radionuclides. Dose 'cost' of the transformation of radionuclides bioavailability

    International Nuclear Information System (INIS)

    Kravets, A.P.; Grodzinsky, D.M.

    1999-01-01

    Soil pathway of radionuclides pollution of agricultural production becomes the main one at the recovery stage of postaccidental period. For this stage dynamics of the human foodstuffs cleaning and rate of internal dose due to consumption are results , of the interaction of three main factors, namely, the rate of the decrease of soil contamination, structure of soil use and transformations of bioavailability of radionuclides. Representation of these ideas in quantitative form, documentation and analysis of the main ecological causes that determine the intensity of the radionuclides mobility in the biological cycle is essential increase the accuracy of the long-term forecast of human dose formation and promote the development of adequate strategies for countermeasures. General formal model and practical method of the ecological forecast of human internal doses has been proposed and used for estimation. Refs. 5 (author)

  11. Review Paper of Radionuclide Monitoring in Food Sample

    International Nuclear Information System (INIS)

    Noor Fadzilah Yusof; Abdul Kadir Ishak; Wo, Y.M.; Nurrul Assyikeen Mohd Jaffary

    2011-01-01

    The uncontrolled release of radionuclides into the atmospheric and aquatic environments may occur as the result of a nuclear or radiological accident. Monitoring of the accidental release at its source and especially direct monitoring of the environmental contamination with radionuclides is necessary for assessment and application of public protective actions and longer term countermeasures as well as emergency workers' protection. In areas historically contaminated with long lived radionuclides monitoring it is essential to protect the public and substantiation of any radiological incidents. Also, dietary pathways can be contaminated with radioactive materials resulting from natural occurrence or man-made applications especially during routine operation, accidents and migration of radionuclides from radioactive waste disposal repositories into the biosphere. Therefore, efforts should be made to determine the presence of radionuclides in a potentially high radiation area especially in operational nuclear facilities. This paper will review the strategies for food monitoring that has been adapted in most countries to obtain baseline data for future reference. Also, this study is discussing the type of food selection commonly collected as sample for radionuclide analysis in different countries over the years. Sampling procedure and analysis also included in this review for better understanding of the analysis. Stake holders' involvement is considered as an important asset in the establishment of monitoring strategies. As a conclusion, future plans for food monitoring programme in Malaysia are recommended as a preparation to embark on the Nuclear Power Plant programme. (author)

  12. White matter pathways critical for language are also critical for resolving proactive interference in working memory

    Directory of Open Access Journals (Sweden)

    Stephanie Kathleen Ries

    2014-04-01

    Full Text Available Background White matter pathways connecting brain regions involved in language processing in the left prefrontal (PFC and temporal cortices have been found to play a critical role in language comprehension (Turken and Dronkers, 2011. Among the frontal brain regions associated with language processing, the left inferior frontal gyrus (lIFG has also been strongly associated with resolving proactive interference in working memory (Jonides and Nee, 2006. Here we investigated whether the white matter pathways connecting the lIFG to the left temporal lobe found to be important in language comprehension were also critical for resolving proactive interference in working memory. Methods We tested 4 patients with left PFC damage involving the lIFG, 5 with left temporal damage and 6 age-matched controls. Critically, 2 left PFC patients and 1 left temporal patient had lesions involving a complete disconnection between the lIFG and the left temporal cortex and the remaining patients had partial disconnection only. Performance was assessed using the Recent Probes test (Monsell, 1978: 4 visually-presented letters are followed by a probe: one central letter. The task was to decide whether or not the probe was part of the immediately preceding set of letters. Whether or not the probe was also part of the previous trial and elicited a positive or negative response was then manipulated and created recent negative (RN and recent positive trials, respectively. RN trials generated interference in trial n compared to non-recent negative (NN trials. Behavioral results were reported using error rates as the dependent variable. Results When the groups were separated based on which cortical lobe was damaged, there was a significant main interference effect (F(1,12=24.94, p <.001, where RN trials were associated with worse performance than NN trials, and a main effect of group (F(2,12=4.65, p <.05, where performance was worse for patients than for controls, but there was

  13. Compilation of poultry and egg parameters for the PATHWAY code

    International Nuclear Information System (INIS)

    Ikenberry, T.A.

    1982-08-01

    The PATHWAY computer code was developed as a part of the foodchain pathway analysis task. The objective was to estimate radionuclide ingestion rates of residents of Lincoln (Nevada), Washington (Utah), and Iron (Utah) counties during the period 1951-1962, which resulted from explosion of nuclear devices at the Nevada Test Site (NTS). Estimation of radionuclide ingestion rates involves determination of radionuclide concentrations in dietary items as a function of time and geographic area, and consumption rates of such items as a function of age and lifestyle. Poultry and eggs may have been relatively significant dose contributors to humans, because of the fairly large consumption rates of these products, and because of potential radionuclide concentration in them. This paper describes nuclide-dependent and nuclide-independent parameters related to poultry products, and the determination of specific values of these parameters. 17 figs., 10 tabs

  14. Uptake of radionuclides and stable elements from paddy soil to rice: a review

    International Nuclear Information System (INIS)

    Uchida, S.; Tagami, K.; Shang, Z.R.; Choi, Y.H.

    2009-01-01

    The critical paths for radionuclides and the critical foods in Asian countries differ from those in Western countries because agricultural products and diets are different. Consequently, safety assessments for Asian countries must consider rice as a critical food. As most rice is produced under flooded conditions, the uptake of radionuclides by rice is affected by soil conditions. In this report, we summarize radionuclide and stable element soil-to-plant transfer factors (TFs) for rice. Field observation results for fallout 137 Cs and stable Cs TFs indicated that while fallout 137 Cs had higher TF than stable Cs over several decades, the GM (geometric mean) values were similar with the GM of TF value for 137 Cs being 3.6 x 10 -3 and that for stable Cs being 2.5 x 10 -3 . Although there are some limitations to the use of TF for stable elements under some circumstances, these values can be used to evaluate long-term transfer of long-lived radionuclides in the environment. The compiled data showed that TF values were higher in brown rice than in white rice because distribution patterns for elements were different in the bran and white parts of rice grains.

  15. Regional and global environmental behaviour of radionuclides from the nuclear fuel cycle

    International Nuclear Information System (INIS)

    1983-02-01

    The operation of nuclear fuel cycle facilities entails the discharge of radioactive effluents to both the atmosphere and aquatic environment. These effluents may contain radionuclides which may be subject of concern for their long-range environmental consequences, in particular, in assessing the health detriment to populations in regions beyond the local environment. The present document reviews information on radionuclides, their environmental pathways and processes and related models and summarizes experiences and studies in this field

  16. Agriculture products as source of radionuclides and some monitoring principles of agriculture near nuclear facilities

    International Nuclear Information System (INIS)

    Aleksakhin, R.M.; Korneev, N.A.; Panteleev, L.I.; Shukhovtsev, B.I.

    1985-01-01

    Migration of radionuclides into agriculture products in regions adjoining the nuclear facilities depends on a large number of factors. Among them is the complex of ecological conditions: meteorological factors, type of soils etc., as well as biological peculiarities of agriculture plants and animals. It is possible to control the radionuclide content administered to man's organism with agriculture products changing large branches of agriculture and varying within the range of seprate branches of industry, taking into account the most effective ways of radionuclide pathways

  17. Radionuclide behavior in the environment

    International Nuclear Information System (INIS)

    Tveten, U.

    1991-09-01

    The purpose of this report is to document the results of the following task: Review for quality and consistency the available data on measurements of initial ground contamination of Chernobyl radionuclides in various parts of Norway and subsequent concentrations of these radionuclides in various environmental media as functions of time. Utilize the data obtained to verify the existing models, or to improve them, for describing radionuclide behavior in the environment. Some of the processes standard were: migration into soil; weathering; resuspension; food-chain contamination; and loss or reconcentration by run-off. The task performed within this contract has been to use post-Chernobyl data from Norway to verify or find areas for possible improvement in the chronic exposure pathway models utilized in MACCS. Work has consisted mainly of collecting and evaluating post-Chernobyl information from Norway or other countries when relevant; but has also included experimental work performed specifically for the current task. In most connections the data available show the models and data in MACCS to be appropriate. A few areas where the data indicate that the MACCS approach is faulty or inadequate are, however, pointed out in the report. These should be examined carefully, and appropriate modifications should eventually be made. 14 refs., 12 figs., 22 tabs

  18. 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)

  19. Radiological assessment of long lived radionuclides transferred through aquatic pathways

    International Nuclear Information System (INIS)

    Florou, H.; Kritidis, P.; Polikarpov, G.G.; Triulzi, C.; Nonnis-Marzano, F.

    1997-01-01

    In this study the main routes of the late Chernobyl debris from the pollution source to the Mediterranean are evaluated, in relation to the long lived radionuclides 137 Cs mainly, while some data on 90 Sr dispersion are also given. The decrease trend of the Chernobyl impact on a closed aquatic system is also evacuated in relation to the 137 Cs deposition during May 1986 over Greece and following measurements during 1987 and 1989

  20. Review of the ecological parameters of radionuclide turnover in vertebrate food chains

    International Nuclear Information System (INIS)

    Kitchings, T.; DiGregorio, D.; Van Voris, P.

    1976-01-01

    Ecological studies of radionuclides in the environment have a long tradition in developing the capability to identify and predict movement and concentration of nuclides in agricultural food chains leading to man. Food chain pathways and transfer coefficients for the nonagricultural portions of natural and managed ecosystems characteristic of affected habitats adjacent to nuclear facilities have not been adequately characterized to establish reliable models for radionuclide releases. This information is necessary in order to assess the impact that such installations will have on the biota of natural ecosystems. Since food chains are the major processes transferring elements from one trophic level to another in terrestrial ecosystems, information is needed on the (a) food-chain transfer pathways, (b) bioconcentration by each trophic component and (c) turnover rates by receptor organisms. These data are prerequisite inputs for food-chain transport models and can be correlated with species characteristics (e.g., body weight and feeding habits), to provide indices for predictive calculations. Application of these models for radionuclide transfer can aid in the assessment of radioactive releases from nuclear reactor facilities to terrestrial nonagricultural food chains

  1. Natural radionuclides in select matrices of terrestrial food chain around Kudankulam nuclear power station, India

    International Nuclear Information System (INIS)

    Ross, E.M.; Wesley, S.G.

    2016-01-01

    Natural radionuclides entering the food chain are mostly derived from the soil. There is a variation in soil radionuclide content in different geographic regions. Uptake of radionuclides by plants also varies from species to species and depends on many factors. Human food and animal feed derived from such regions may have varying levels of radionuclides. Intake of food/feed will be reflected in the next consumer level of the food chain. Such studies are essential around a nuclear power plant where there can be exposure from natural as well as artificial radionuclides. In this study an effort was taken to study the intake and excretion of 40 K, 226 Ra and 228 Ra levels along the soil-grass-cow pathway

  2. Critical Role of the Sphingolipid Pathway in Stroke: a Review of Current Utility and Potential Therapeutic Targets.

    Science.gov (United States)

    Sun, Na; Keep, Richard F; Hua, Ya; Xi, Guohua

    2016-10-01

    Sphingolipids are a series of cell membrane-derived lipids which act as signaling molecules and play a critical role in cell death and survival, proliferation, recognition, and migration. Sphingosine-1-phosphate acts as a key signaling molecule and regulates lymphocyte trafficking, glial cell activation, vasoconstriction, endothelial barrier function, and neuronal death pathways which plays a critical role in numerous neurological conditions. Stroke is a second leading cause of death all over the world and effective therapies are still in great demand, including ischemic stroke and hemorrhagic stroke as well as poststroke repair. Significantly, sphingolipid activities change after stroke and correlate with stroke outcome, which has promoted efforts to testify whether the sphingolipid pathway could be a novel therapeutic target in stroke. The sphingolipid metabolic pathway, the connection between the pathway and stroke, as well as therapeutic interventions to manipulate the pathway to reduce stroke-induced brain injury are discussed in this review.

  3. Recent research involving the transfer of radionuclides to milk

    International Nuclear Information System (INIS)

    Ward, G.M.

    1989-01-01

    The radionuclides in milk, which result from exposure of dairy cows to radioactive fallout, are a major factor in assessment of internal radiation of humans. To evaluate the radionuclide intake of people from fallout-contaminated milk requires information about feed sources and milk distribution. Pasture intake and the shelf-life of milk are important factors in the case of a short-lived radionuclide like 131 I. Large-scale human radiation assessment studies are underway, all of which consider the dairy food chain as a critical component. These include retrospective studies of fallout from nuclear weapons testing at the Nevada site in the 1950s and the impact of the Chernobyl accident on April 26, 1986

  4. Natural analogue approach for estimating the health risks from release and migration of radionuclides from radioactive waste

    International Nuclear Information System (INIS)

    Gilbert, T.L.

    1983-01-01

    The health risks from radioactive waste may be expressed as a sum of products of transfer factors that characterize the causal chain of events between disposal of radionuclides in a waste field and the consequent health effects. Model estimates for the transfer factors are commonly obtained by modeling transport and other mechanisms in the subsystems that form the links in the causal chain. Natural estimates of some conversion factors for naturally occurring radionuclides can be obtained from data on the concentrations of naturally occurring radionuclides in soil, food, and the human body. These model and natural estimates can be used with scaling procedures to estimate the uncertainties and to obtain better estimates of the values. The scaling procedures take into account the differences in the source characteristics for radionuclides in a waste field of limited size and for radionuclides generally distributed in the natural environment. The ratios of the natural estimates to the model estimates for several transfer factors and several radionuclides belonging to the U-238 decay series have been determined. These ratios range from 1/8 to 4/1 for food-concentration/source-concentration transfer factors for the food pathways and from 1 to 77 for dose-rate/source-concentration transfer factors for the internal radiation dose pathways to various organs. 14 references

  5. Distribution of radionuclides by organs of wild animals

    International Nuclear Information System (INIS)

    Kudryashov, V.P.; Korol', R.A.; Bykovskij, V.V.; Bazhanov, V.A.

    2008-01-01

    The distribution of radionuclides by organs of wild animals, are studied, for evacuation zone of Chernobyl NPP. The distribution of Cs 137 have a total character, Sr 90 are distributed on critical organs, us a rule. (authors)

  6. Aspects of radiation exposure amongst the population after release of radionuclides from terminal stores

    International Nuclear Information System (INIS)

    Proehl, G.; Mueller, H.; Paretzke, H.G.

    1989-08-01

    The release of radionuclides from terminal stores may lead to the contamination of ground water lying close to the surface, after the radionuclides have migrated within the covering rock. Use of this water can result in radiation exposure for human beings along many exposure pathways. In order to assess the radiation exposure from these exposure pathways the model ECOSYS-87-B was developed, as an extension of ECOSYS (Jacobi et al. 1985). On the basis of a standardized contamination of the ground water, the potential radiation exposure of a one-year-old and an adult are calculated, under the assumption that the entire food supply of these persons was produced using radioactively contaminated water. Special questions on the transfer of radionuclides in food chains are discussed, and, in particular, the mineral content of the water and the influence of the chemical form of the radionuclides dissolved in the ground water on their transfer within the food chain are explained. There is also a study of the extent to which various physiologically-based nutritional habits influence the radiation exposure of a human being. Various criteria for the evaluation of radiation exposure are discussed. (orig./HP) [de

  7. Association between mutations of critical pathway genes and survival outcomes according to the tumor location in colorectal cancer.

    Science.gov (United States)

    Lee, Dae-Won; Han, Sae-Won; Cha, Yongjun; Bae, Jeong Mo; Kim, Hwang-Phill; Lyu, Jaemyun; Han, Hyojun; Kim, Hyoki; Jang, Hoon; Bang, Duhee; Huh, Iksoo; Park, Taesung; Won, Jae-Kyung; Jeong, Seung-Yong; Park, Kyu Joo; Kang, Gyeong Hoon; Kim, Tae-You

    2017-09-15

    Colorectal cancer (CRC) develops through the alteration of several critical pathways. This study was aimed at evaluating the influence of critical pathways on survival outcomes for patients with CRC. Targeted next-generation sequencing of 40 genes included in the 5 critical pathways of CRC (WNT, P53, RTK-RAS, phosphatidylinositol-4,5-bisphosphate 3-kinase [PI3K], and transforming growth factor β [TGF-β]) was performed for 516 patients with stage III or high-risk stage II CRC treated with surgery followed by adjuvant fluoropyrimidine and oxaliplatin chemotherapy. The associations between critical pathway mutations and relapse-free survival (RFS) and overall survival were analyzed. The associations were further analyzed according to the tumor location. The mutation rates for the WNT, P53, RTK-RAS, PI3K, and TGF-β pathways were 84.5%, 69.0%, 60.7%, 30.0%, and 28.9%, respectively. A mutation in the PI3K pathway was associated with longer RFS (adjusted hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.36-0.99), whereas a mutation in the RTK-RAS pathway was associated with shorter RFS (adjusted HR, 1.60; 95% CI, 1.01-2.52). Proximal tumors showed a higher mutation rate than distal tumors, and the mutation profile was different according to the tumor location. The mutation rates of Kirsten rat sarcoma viral oncogene homolog (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), and B-Raf proto-oncogene serine/threonine kinase (BRAF) were higher in proximal tumors, and the mutation rates of adenomatous polyposis coli (APC), tumor protein 53 (TP53), and neuroblastoma RAS viral oncogene homolog (NRAS) were higher in distal tumors. The better RFS with the PI3K pathway mutation was significant only for proximal tumors, and the worse RFS with the RTK-RAS pathway mutation was significant only for distal tumors. A PI3K pathway mutation was associated with better RFS for CRC patients treated with adjuvant chemotherapy, and an RTK

  8. Holistic assessment to put mobile radionuclides in perspective

    International Nuclear Information System (INIS)

    Umeki, H.

    2009-01-01

    Some radionuclides are inherently more mobile than others in the near- and far-field of repository systems and hence, if long-lived, tend to dominate the calculated doses in normal evolution scenarios. High mobility generally a consequence of high solubility coupled to low sorption does not, however, necessarily mean that a particular radionuclide is problematic in terms of repository safety. A more holistic approach, considering the entire safety case, gives a better indication of the critical nuclides and the R and D required to strengthen the assurance of safety. (author)

  9. Evaluation Of Groundwater Pathways And Travel Times From The Nevada Test Site To The Potential Yucca Mountain Repository

    International Nuclear Information System (INIS)

    K.F. Pohlman; J. Zhu; M. Ye; J. Chapman; C. Russell; D.S. Shafer

    2006-01-01

    Yucca Mountain (YM), Nevada, has been recommended as a deep geological repository for the disposal of spent fuel and high-level radioactive waste. If YM is licensed as a repository by the Nuclear Regulatory Commission, it will be important to identify the potential for radionuclides to migrate from underground nuclear testing areas located on the Nevada Test Site (NTS) to the hydraulically downgradient repository area to ensure that monitoring does not incorrectly attribute repository failure to radionuclides originating from other sources. In this study, we use the Death Valley Regional Flow System (DVRFS) model developed by the U.S. Geological Survey to investigate potential groundwater migration pathways and associated travel times from the NTS to the proposed YM repository area. Using results from the calibrated DVRFS model and the particle tracking post-processing package MODPATH, we modeled three-dimensional groundwater advective pathways in the NTS and YM region. Our study focuses on evaluating the potential for groundwater pathways between the NTS and YM withdrawal area and whether travel times for advective flow along these pathways coincide with the prospective monitoring timeframe at the proposed repository. We include uncertainty in effective porosity, as this is a critical variable in the determination of time for radionuclides to travel from the NTS region to the YM withdrawal area. Uncertainty in porosity is quantified through evaluation of existing site data and expert judgment and is incorporated in the model through Monte Carlo simulation. Since porosity information is limited for this region, the uncertainty is quite large and this is reflected in the results as a large range in simulated groundwater travel times

  10. Recommendations concerning classification of and discharge standards for radionuclide laboratories

    International Nuclear Information System (INIS)

    1985-01-01

    In the report recommendations are made for the limitation of the radioactive gaseous and liquid effluents from radionuclide laboratories. The recommended values are based on a radiation exposure for members of a critical group in the population corresponding to 1% of the dose limit for individual members of the public as recommended by the ICRP. Based on these standards a classification of radionuclide laboratories is proposed. It is recommended to retain the present Dutch classification in A-, B-, C- and D-laboratories. The report contains appendices with detailed data about the transport routes of radionuclides in the environment and the subsequent irradiation of members of the public. (orig.)

  11. Radionuclide Content of Pasteurized Milk Sold in Mafikeng, South Africa

    International Nuclear Information System (INIS)

    Olobatoke, R.; Mathuthu, M.

    2015-01-01

    Many food animals which are important components of human food chain are effective collectors of radionuclides from the environment particularly contaminated forages, and therefore represent a significant pathway for the transfer of radionuclides to humans. Many important radionuclides are readily transferred to milk thus the product is considered as one of the basic food items recommended for the assessment of radionuclide exposure within a population. The current study aimed at assessing the radionuclide content of commercial milk commonly sold in South Africa in other to set a baseline data for radionuclide concentration of the products. Three popular brands of commercial milk (A, B and C) were sampled, with two samples obtained for each brand. The concentration of individual radionuclide in the milk samples, particularly "1"3"1I, "1"3"7Cs and "2"3"5U was measured by gamma spectroscopy. The results showed that brand A had the highest concentrations of "2"3"5U and "1"3"7Cs (203 and 324 mBq/l respectively) but the lowest concentration of "1"3"1I (6.4 mBq/l). The highest concentration of "1"3"1I (148 mBq/l) was detected in brand B whereas both "2"3"5U and "1"3"1I were not detected in brand C. All the values however were well below the new standard limits for individual radionuclides in milk established by the Japanese Ministry of Health, Labour and Welfare. This study indicates that the commercial milk brands assessed pose no radiation health threat to the consumers. (author)

  12. 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.

  13. Analysis of radionuclide dispersion at normal condition for AEC 1000 MW reactor power

    International Nuclear Information System (INIS)

    Sri Kuntjoro

    2010-01-01

    Analysis for radionuclide dispersion for the Atomic Energy Agency (AEC) 3,568 MWth Power Reactor, equal to the 1,000 MWe at normal condition has been done. Analysis was done for two piles that is separated by 500 m distance and angle of 90° one to other. Initial pace in doing the analysis is to determine reactors source term using ORIGEN2 and EMERALD NORMAL. computer code program. ORIGEN2 applied to determine radionuclide inventory emerged in the reactor. Hereinafter, by using Emerald Normal Computer code is calculated source term reaching the reactor stack. To analyze dose received by population is done by using PC-CREAM computer code. Calculation done for one and two PLTN attached in site candidate of plants. The result showed is that the highest radionuclide release for one PLTN is at 1 km distance and to 9 th zone toward ( 19.25° ) and for two PLTN is at 1 km distance and to 10 th zone toward (21.75° ). Radionuclide which up to population through two pathways that are foodstuff and inhalation. To foodstuff comes from radionuclide I 131 , and the biggest passed from milk product with 53.40 % for one and also two PLTN For inhalation pathway the highest radionuclide contribution come from Kr 85m is about 53.80 %. The highest total dose received by population is at 1 Km distance received by baby that is 4.10 µSi and 11.26 µSi for one and two PLTN respectively. Those result are very small compared to the maximum permission dose to population issued by regulatory body that is equal to 1 mSi. (author)

  14. RIVER-RAD: A computer code for simulating the transport of radionuclides in rivers

    International Nuclear Information System (INIS)

    Hetrick, D.M.; McDowell-Boyer, L.M.; Sjoreen, A.L.; Thorne, D.J.; Patterson, M.R.

    1992-11-01

    A screening-level model, RIVER-RAD, has been developed to assess the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. The purpose of this report is to provide a description of the model and a user's manual for the FORTRAN computer code

  15. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  16. Implementing critical pathways and a multidisciplinary team approach to cardiovascular disease management.

    Science.gov (United States)

    Peterson, Eric D; Albert, Nancy M; Amin, Alpesh; Patterson, J Herbert; Fonarow, Gregg C

    2008-09-08

    According to several medical registries, there is a need to improve the care of post-myocardial infarction (MI) patients, especially those with left ventricular dysfunction (LVD) and heart failure. This can potentially be achieved by implementing disease management programs, which include critical pathways, patient education, and multidisciplinary hospital teams. Currently, algorithms for critical pathways, including discharge processes, are lacking for post-MI LVD patients. Such schemes can increase the use of evidence-based medicines proved to reduce mortality. Educational programs are aimed at increasing patients' awareness of their condition, promoting medication compliance, and encouraging the adoption of healthy behaviors; such programs have been shown to be effective in improving outcomes of post-MI LVD patients. Reductions in all-cause hospitalizations and medical costs as well as improved survival rates have been observed when a multidisciplinary team (a nurse, a pharmacist, and a hospitalist) is engaged in patient care. In addition, the use of the "pay for performance" method, which can be advantageous for patients, physicians, and hospitals, may potentially improve the care of post-MI patients with LVD.

  17. Assessment of atmospherically-released radionuclides using the computerized radiological risk investigation system

    International Nuclear Information System (INIS)

    Nelson, C.B.; Sjoreen, A.L.; Miller, C.W.; Baes, C.F. III.

    1986-01-01

    For radionuclides, the standards are in terms of an annual dose, and the regulations require assurance that no member of the general public receives a dose in excess of that standard. Thus, spatial variations in the population around an emission source must be considered. Furthermore, for most chemical pollutants the standards are written in terms of an air concentration while for radionuclides other pathways of exposure, e.g., uptake of the airborne emissions by terrestrial food chains must also be considered. The remainder of this paper discusses the computer codes that make up the CRRIS and how they are used to perform an assessment of the health impacts on man of radionuclides released to the atmosphere

  18. Probabilistic Criticality Consequence Evaluation

    International Nuclear Information System (INIS)

    P. Gottlieb; J.W. Davis; J.R. Massari

    1996-01-01

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development (WPD) department with the objective of providing a comprehensive, conservative estimate of the consequences of the criticality which could possibly occur as the result of commercial spent nuclear fuel emplaced in the underground repository at Yucca Mountain. The consequences of criticality are measured principally in terms of the resulting changes in radionuclide inventory as a function of the power level and duration of the criticality. The purpose of this analysis is to extend the prior estimates of increased radionuclide inventory (Refs. 5.52 and 5.54), for both internal and external criticality. This analysis, and similar estimates and refinements to be completed before the end of fiscal year 1997, will be provided as input to Total System Performance Assessment-Viability Assessment (TSPA-VA) to demonstrate compliance with the repository performance objectives

  19. Radionuclides in sporocarps of medicinaly important fungi of Fruska Gora hill

    International Nuclear Information System (INIS)

    Karaman, M.; Matavulj, M.; Čonkić, L.

    2002-01-01

    The content of radionuclides in six lignicolous saprophytic and parasitic fungal species was analyzed. Samples were collected in 1999 autumn at two sites of the Fruska Gora Hill. Since fungi absorb radionuclides mostly from the substrate, soil and tree samples were also collected and analyzed. Certain characteristics of fungal species play an important role in the process of radionuclide absorption. On the other hand, the degree of radionuclide accumulation is very important for the fungi of potential pharmaceutical significance. The results on the radioactivity concentration in the analyzed fungi could be used both for the bioindication investigations, soil and substrate contamination in particular, and for estimation of the forest ecological status. The activity concentration level of most critical radionuclide 137Cs was about ten times lower in these species then in Pholiota squarrosa, characterized by the highest activity concentration level of 55(4) Bq/kg (d.m.) [sr

  20. Methods of separating short half-life radionuclides from a mixture of radionuclides

    International Nuclear Information System (INIS)

    Bray, L.A.; Ryan, J.L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of 223 Ra and 225 Ac, from a radionuclide ''cow'' of 227 Ac or 229 Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ''cow'' forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ''cow'' from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ''cow''. In one embodiment the radionuclide ''cow'' is the 227 Ac, the at least one daughter radionuclide is a 227 Th and the product radionuclide is the 223 Ra and the first nitrate form ion exchange column passes the 227 Ac and retains the 227 Th. In another embodiment the radionuclide ''cow'' is the 229 Th, the at least one daughter radionuclide is a 225 Ra and said product radionuclide is the 225 Ac and the 225 Ac and nitrate form ion exchange column retains the 229 Th and passes the 225 Ra/Ac. 8 figs

  1. Radionuclide transfer to fruit in the IAEA TRS No. 472

    Directory of Open Access Journals (Sweden)

    Giosuè S.

    2012-04-01

    Full Text Available This paper describes the approach taken to present the information on fruits in the IAEA report TRS No. 472, supported by the IAEA-TECDOC-1616, which describes the key transfer processes, concepts and conceptual models regarded as important for dose assessment, as well as relevant parameters for modelling radionuclide transfer in fruits. Information relate to fruit plants grown in agricultural ecosystems of temperate regions. The relative significance of each pathway after release of radionuclides depends upon the radionuclide, the kind of crop, the stage of plant development and the season at time of deposition. Fruit intended as a component of the human diet is borne by plants that are heterogeneous in habits, and morphological and physiological traits. Information on radionuclides in fruit systems has therefore been rationalised by characterising plants in three groups: woody trees, shrubs, and herbaceous plants. Parameter values have been collected from open literature, conference proceedings, institutional reports, books and international databases. Data on root uptake are reported as transfer factor values related to fresh weight, being consumption data for fruits usually given in fresh weight.

  2. Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

    Science.gov (United States)

    Ge, Yue; Bruno, Maribel; Haykal-Coates, Najwa; Wallace, Kathleen; Andrews, Debora; Swank, Adam; Winnik, Witold; Ross, Jeffrey A.

    2016-01-01

    Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses and protein response-based biochemical pathways represents a key mechanism through which nickel induces cytotoxicity and carcinogenesis. To identify protein responses and biochemical pathways that are critical to nickel-induced toxicity responses, we measured cytotoxicity and changes in expression and phosphorylation status of 14 critical biochemical pathway regulators in human BEAS-2B cells exposed to four concentrations of nickel using an integrated proteomic approach. A subset of the pathway regulators, including interleukin-6, and JNK, were found to be linearly correlated with cell viability, and may function as molecular determinants of cytotoxic responses of BEAS-2B cells to nickel exposures. In addition, 128 differentially expressed proteins were identified by two dimensional electrophoresis (2-DE) and mass spectrometry. Principal component analysis, hierarchical cluster analyses, and ingenuity signaling pathway analysis (IPA) identified putative nickel toxicity pathways. Some of the proteins and pathways identified have not previously been linked to nickel toxicity. Based on the consistent results obtained from both ELISA and 2-DE proteomic analysis, we propose a core signaling pathway regulating cytotoxic responses of human BEAS-2B cells to nickel exposures, which integrates a small set of proteins involved in glycolysis and gluconeogenesis pathways, apoptosis, protein degradation, and stress responses including inflammation and oxidative stress. PMID:27626938

  3. Review of the ecological parameters of radionuclide turnover in vertebrate food chains

    International Nuclear Information System (INIS)

    Kitchings, T.; DiGregorio, D.; Van Voris, P.

    1975-01-01

    Ecological studies of radionuclides in the environment have a long tradition in developing the capability to identify and predict movement and concentration of nuclides in agronomic food chains leading to man. Food chain pathways and transfer coefficients for the non-agronomic portions of natural and managed ecosystems characteristic of affected habitats adjacent to nuclear facilities have not been adequately characterized to establish reliable dispersion models for radionuclide releases. This information is necessary in order to assess the impact that such installations will have on the biota of natural ecosystems. Since food chains are the major processes transferring elements from one trophic level to another in terrestrial ecosystems, information is needed on the food-chain transfer pathways, bioconcentration by each trophic component, and turnover rates by receptor organisms. These data are prerequisite inputs for food-chain transport models and can be correlated with species characteristics (e.g., body weight and feeding habitats), to provide indices for predictive dispersion calculations. Application of these models for radionuclide transfer can aid in the assessment of radioactive releases from nuclear reactor facilities to terrestrial non-agronomic food chains. (U.S.)

  4. Methods of separating short half-life radionuclides from a mixture of radionuclides

    Science.gov (United States)

    Bray, Lane A.; Ryan, Jack L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

  5. Biological pathways of exposure and ecotoxicity values for uranium and associated radionuclides: Chapter D in Hydrological, geological, and biological site characterization of breccia pipe uranium deposits in Northern Arizona

    Science.gov (United States)

    Hinck, Jo E.; Linder, Greg L.; Finger, Susan E.; Little, Edward E.; Tillitt, Donald E.; Kuhne, Wendy

    2010-01-01

    This chapter compiles available chemical and radiation toxicity information for plants and animals from the scientific literature on naturally occurring uranium and associated radionuclides. Specifically, chemical and radiation hazards associated with radionuclides in the uranium decay series including uranium, thallium, thorium, bismuth, radium, radon, protactinium, polonium, actinium, and francium were the focus of the literature compilation. In addition, exposure pathways and a food web specific to the segregation areas were developed. Major biological exposure pathways considered were ingestion, inhalation, absorption, and bioaccumulation, and biota categories included microbes, invertebrates, plants, fishes, amphibians, reptiles, birds, and mammals. These data were developed for incorporation into a risk assessment to be conducted as part of an environmental impact statement for the Bureau of Land Management, which would identify representative plants and animals and their relative sensitivities to exposure of uranium and associated radionuclides. This chapter provides pertinent information to aid in the development of such an ecological risk assessment but does not estimate or derive guidance thresholds for radionuclides associated with uranium. Previous studies have not attempted to quantify the risks to biota caused directly by the chemical or radiation releases at uranium mining sites, although some information is available for uranium mill tailings and uranium mine closure activities. Research into the biological impacts of uranium exposure is strongly biased towards human health and exposure related to enriched or depleted uranium associated with the nuclear energy industry rather than naturally occurring uranium associated with uranium mining. Nevertheless, studies have reported that uranium and other radionuclides can affect the survival, growth, and reproduction of plants and animals. Exposure to chemical and radiation hazards is influenced by a

  6. Health risks from radionuclides released into the Clinch River

    International Nuclear Information System (INIS)

    Thomas, B.A.; Hoffman, F.O.; Miller, L.F.

    1999-01-01

    The purpose of this work is to estimate off-site radiation doses and health risks (with uncertainties) associated with the release of radionuclides from the X-10 site. Following an initial screening analysis, the exposure pathways of interest included fish ingestion, drinking water ingestion, the ingestion of milk and meat, and external exposure from shoreline sediment. Four representative locations along the Clinch River, from the White Oak Creek Embayment to the city of Kingston, were chosen. The demography of the lower Clinch River supplied information dealing with land use that aided in the determination of sites on which to focus efforts. The locations that proved to be the most significant included Jones Island at Clinch River Mile (CRM) 20.5, Grassy Creek and K-25 (CRM 14), Kingston Steam Plant (CRM 3.5), and the city of Kingston (CRM 0). These areas of interest have historically been and are still primarily agricultural and residential areas. Reference individuals were determined with respect to the pathways involved. The primary radionuclides of interest released from the X-10 facility into the Clinch River via White Oak Creek were identified in the initial screening analysis as 137 Cs, 90 Sr, 60 Co, 106 Ru, 144 Ce, 131 I, 95 Zr, and 95 Nb. Of these radionuclides, 137 Cs, 60 Co, 106 Ru, 90 Sr, 144 Ce, 95 Zr, and 95 Nb were evaluated for their contribution to the external exposure pathway. This study utilized an object-oriented modeling software package that provides an alternative to the spreadsheet, providing graphical influence diagrams to show qualitative structure of models, hierarchical models to organize complicated models into manageable modules, and intelligent arrays with the power to scale up simple models to handle large problems. The doses and risks estimated in this study are not significant enough to cause a detectable increase in health effects in the population. In most cases, the organ does are well below the limits of epidemiological

  7. Dependence on age at intake of committed dose equivalents from radionuclides

    International Nuclear Information System (INIS)

    Adams, N.

    1981-01-01

    The dependence of committed dose equivalents on age at intake is needed to assess the significance of exposures of young persons among the general public resulting from inhaled or ingested radionuclides. The committed dose equivalents, evaluated using ICRP principles, depend on the body dimensions of the young person at the time of intake of a radionuclide and on subsequent body growth. Representation of growth by a series of exponential segments facilitates the derivation of general expressions for the age dependence of committed dose equivalents if metabolic models do not change with age. The additional assumption that intakes of radionuclides in air or food are proportional to a person's energy expenditure (implying age-independent dietary composition) enables the demonstration that the age of the most highly exposed 'critical groups' of the general public from these radionuclides is either about 1 year or 17 years. With the above assumptions the exposure of the critical group is less than three times the exposure of adult members of the general public. Approximate values of committed dose equivalents which avoid both underestimation and excessive overestimation are shown to be obtainable by simplified procedures. Modified procedures are suggested for use if metabolic models change with age. (author)

  8. Uptake of radionuclides by farm animals close to a major nuclear installation

    International Nuclear Information System (INIS)

    Sumerling, T.J.; Green, N.; Dodd, N.J.

    1984-01-01

    A field investigation of the transfer of artificially produced radionuclides in the pasture-cow-milk pathway has been made at a farm close to the nuclear fuel reprocessing installation at Sellafield. The routine discharges from the plant have resulted in enhanced levels of several artificial radionuclides in the local environment. The annual depositions of 90 Sr and 137 Cs at the farm were a factor of about five higher than the average deposition of these radionuclides in the UK. Even if extremely cautious assumptions concerning local eating habits are made, the consumption of meat and dairy products from this farm would give rise to an annual activity intake of less than one percent of the limit for adult members of the public. (orig./HP)

  9. Criteria of reference radionuclides for safety analysis of spent fuel waste disposal

    International Nuclear Information System (INIS)

    Suryanto

    1998-01-01

    Study on the criteria for reference radionuclides selection for assessment on spent fuel disposal have done. The reference radionuclides in this study means radionuclides are predicted to contribute of the most radiological effect for man if spent fuel waste are discharged on deep geology formation. The research was done by investigate critically of parameters were used on evaluation a kind of radionuclide. Especially, this research study of parameter which relevant disposal case and or spent fuel waste on deep geology formation . The research assumed that spent fuel discharged on deep geology by depth 500-1000 meters from surface of the land. The migration scenario Radionuclides from waste form to man was assumed particularly for normal release in which Radionuclides discharge from waste form in a series thorough container, buffer, geological, rock, to fracture(fault) and move together with ground water go to biosphere and than go into human body. On this scenario, the parameter such as radionuclides inventory, half life, heat generation, hazard index based on maximum permissible concentration (MPC) or annual limit on intake (ALI) was developed as criteria of reference radionuclides selection. The research concluded that radionuclides inventory, half live, heat generated, hazard index base on MPC or ALI can be used as criteria for selection of reference Radionuclide. The research obtained that the main radionuclides are predicted give the most radiological effect to human are as Cs-137, Sr-90, I-129, Am-243, Cm-244, Pu-238, Pu-239, Pu-240. The radionuclides reasonable to be used as reference radionuclides in safety analysis at spent fuel disposal. (author)

  10. Present status and perspective of radiochemical analysis of radionuclides in Nordic countries

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Olsson, Mattias; Togneri, Laura

    2016-01-01

    Radiochemical analysis plays a critical role in the determination of pure beta and alpha emitting radionuclides for environmental monitoring, radioecology, decommissioning, nuclear forensics and geological dating. A remarkable development on radiochemical analysis has been achieved in the past...... of radionuclides, especially in Nordic countries; some requirements from nuclear industries and research organizations, as well as perspectives on the development of radiochemical analysis are discussed....

  11. Risk methodology for geologic disposal of radioactive waste: model description and user manual for Pathways model

    International Nuclear Information System (INIS)

    Helton, J.C.; Kaestner, P.C.

    1981-03-01

    A model for the environmental movement and human uptake of radionuclides is presented. This model is designated the Pathways-to-Man Model and was developed as part of a project funded by the Nuclear Regulatory Commission to design a methodology to assess the risk associated with the geologic disposal of high-level radioactive waste. The Pathways-to-Man Model is divided into two submodels. One of these, the Environmental Transport Model, represents the long-term distribution and accumulation of radionuclides in the environment. This model is based on a mixed-cell approach and describes radionuclide movement with a system of linear differential equations. The other, the Transport-to-Man Model, represents the movement of radionuclides from the environment to man. This model is based on concentration ratios. General descriptions of these models are provided in this report. Further, documentation is provided for the computer program which implements the Pathways Model

  12. Protecting Critical Infrastructure by Identifying Pathways of Exposure to Risk

    Directory of Open Access Journals (Sweden)

    Philip O’Neill

    2013-08-01

    Full Text Available Increasingly, our critical infrastructure is managed and controlled by computers and the information networks that connect them. Cyber-terrorists and other malicious actors understand the economic and social impact that a successful attack on these systems could have. While it is imperative that we defend against such attacks, it is equally imperative that we realize how best to react to them. This article presents the strongest-path method of analyzing all potential pathways of exposure to risk – no matter how indirect or circuitous they may be – in a network model of infrastructure and operations. The method makes direct use of expert knowledge about entities and dependency relationships without the need for any simulation or any other models. By using path analysis in a directed graph model of critical infrastructure, planners can model and assess the effects of a potential attack and develop resilient responses.

  13. Radionuclide trap

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1978-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition

  14. Plant rhizosphere processes influencing radionuclide mobility in soil

    International Nuclear Information System (INIS)

    Cataldo, D.A.; Cowan, C.E.; McFadden, K.M.; Garland, T.R.; Wildung, R.E.

    1987-10-01

    Native vegetation associated with commercial low-level waste disposal sites has the potential for modifying the soil chemical environment over the long term and, consequently, the mobility of radionuclides. These effects were assessed for coniferous and hardwood tree species by using plants grown in lysimeter systems and examining their influence on soil solution chemistry using advanced analytical and geochemical modeling techniques. The study demonstrated formation of highly mobile anionic radionuclide complexes with amino acids, peptides, and organic acids originating from plant leaf litter and roots. The production of complexing agents was related to season and tree species, suggesting that vegetation management and exclusion may be appropriate after a site is closed. This research provides a basis for focusing on key complexing agents in future studies to measure critical affinity constants and to incorporate this information into mathematical models describing biological effects on radionuclide mobility. 26 refs., 5 figs., 23 tabs

  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. Natural uranium-series radionuclide inventories in coastal and oceanic waters of the south-western Pacific - insights into trace metal flux and removal pathway analysis

    International Nuclear Information System (INIS)

    Szymczak, R.; Jeffree, R.A.; Peck, G.A.

    2003-01-01

    Participate scavenging of trace metals plays a major role in determining their ecosystem flux and incident dissolved concentrations. Differences in the half-lives and biogeochemical behaviour of natural uranium series radioisotope pairs (eg. 238 U/ 234 Th, 210 Pb/ 210 Po) allow their application as oceanic process tracers. Coincidental measurements of dissolved and particulate trace element concentrations and inventories of radionuclides in the Noumea coral lagoon and adjacent offshore waters were used to quantify water column flux rates and provide insights on removal pathway analysis. Understanding prevailing pathways and respective flux rates of pollutants in specific coastal and oceanic systems will assist to establish the fate and consequence of pollutants and allow sustainable management strategies to be developed. Both natural and pollutant chemical species introduced to the marine environment may either remain benign in solution or undergo physiological uptake by biota, but most often associate with colloids and fine particles, which subsequent undergo aggregation, sedimentation and removal to the sea floor

  17. AIR AND RADON PATHWAY MODELING FOR THE F-AREA TANK FARM

    International Nuclear Information System (INIS)

    Dixon, K; Mark Phifer, M

    2007-01-01

    The F-Area Tank Farm (FTF) is located within F-Area in the General Separations Area (GSA) of the Savannah River Site (SRS) as seen in Figure 1. The GSA contains the F and H Area Separations Facilities, the S-Area Defense Waste Processing Facility, the Z-Area Saltstone Facility, and the E-Area Low-Level Waste Disposal Facilities. The FTF is a nearly rectangular shaped area and comprises approximately 20 acres, which is bounded by SRS coordinates N 76,604.5 to N 77,560.0 and E 52,435.0 to E 53,369.0. SRS is in the process of preparing a Performance Assessment (PA) to support FTF closure. As part of the PA process, an analysis was conducted to evaluate the potential magnitude of gaseous release of radionuclides from the FTF over the 100-year institutional control period and 10,000-year post-closure compliance period. Specifically, an air and radon pathways analysis has been conducted to estimate the flux of volatile radionuclides and radon at the ground surface due to residual waste remaining in the tanks following closure. This analysis was used as the basis to estimate the dose to the maximally exposed individual (MEI) for the air pathway per Curie (Ci) of each radionuclide remaining in the combined FTF waste tanks. For the air pathway analysis, several gaseous radionuclides were considered. These included carbon-14 (C-14), chlorine-36 (Cl-36), iodine-129 (I-129), selenium-79 (Se-79), antimony-125 (Sb-125), tin-126 (Sn-126), tritium (H-3), and technetium-99 (Tc-99). The dose to the MEI was estimated at the SRS Boundary during the 100 year institutional control period. For the 10,000 year post closure compliance period, the dose to the MEI was estimated at the 100 m compliance point. For the radon pathway analysis, five parent radionuclides and their progeny were analyzed. These parent radionuclides included uranium-238 (U-238), plutonium-238 (Pu-238), uranium-234 (U-234), thorium-230 (Th-230), and radium-226 (Ra-226). The peak flux of radon-222 due to each parent

  18. A model for radionuclide transport in the Cooling Water System

    International Nuclear Information System (INIS)

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA

  19. Studies on influence of biological factors on concentration of radionuclides

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    Biological factors influencing the concentration of radionuclides were studied from the points of uptake through digestive tract, food as pathways, and metabolic activities. The uptake of radionuclides by marine fishes through digestive tract was determined by whole body counter. 137 Cs, 65 Zn, 131 I, 54 Mn, 60 Co, 85 Sr, and 144 Ce were used as tracers and was given with solid feed. The feed given was excreated 24 to 48 hours later in small of middle sized fishes, and 20 to 48 hours later in large sized fishes. The uptake rate of 137 Cs and 65 Zn was high absorption of 20 to 80 per cent, that of 131 I, 60 Co and 54 Mn was not remarkable, and that of 85 Sr and 144 Ce was low absorption. The biological concentration of 137 Cs through pathways of food. In fishes taking up radionuclides through contaminated food, concentration factor increased in accordance with contamination level. In addition, radionuclides with small uptake but delayed excretion and those with high concentration rate could be the factors to decide the concentration factors of marine organisms. In order to study the relationship between metabolic activities and concentration, the uptake of one-year old fishes and adult fishes, and fishes fed and those non-fed were compared. One-year fishes took up large amount of 85 Sr during short period, however, concentration by metabolism in adult fishes was slow. Comparing feeding group and non-feeding group, the former showed 85 Sr concentration factor of 1.5 to 2 times that of the later, and the later showed 137 Cs concentration factor of 2 to 4 times that of the former. However, both uptake and excretion were rapid suggesting that taking food activated the metabolism of substances. (Kanao, N.)

  20. Influence of the composition of radionuclide mixtures on the maximum permissible concentration

    International Nuclear Information System (INIS)

    Schillinger, K.; Schuricht, V.

    1975-08-01

    By dividing radionuclides according to their formation mechanisms it is possible to assess the influence of separate partial mixtures on the maximum permissible concentration (MPC) of the total mixture without knowing exactly their contribution to the total activity. Calculations showed that the MPC of a total mixture of unsoluble radionuclides, which may occur in all fields of peaceful uses of nuclear energy, depends on the gastrointestinal tract as the critical organ and on the composition of the fission product mixture. The influence of fractionation on the MPC can be reglected in such a case, whereas in case of soluble radionuclides this is not possible

  1. Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

    Energy Technology Data Exchange (ETDEWEB)

    Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

    1985-01-01

    Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.

  2. Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

    International Nuclear Information System (INIS)

    Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

    1985-01-01

    Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates

  3. Radiological consequences of radionuclide releases to sewage systems from hospitals in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Rodolfo; Cruz, Idalmis de la [Facilia AB (Sweden); Bergman, Synnoeve [Vattenfall Power Consultants AB (Sweden); Hasselblad, Serena [Callido AB (Sweden)

    2007-08-15

    The report addresses radioactive discharges to sewers originating from hospitals, mainly in the form of the excretion of patients treated with radioisotopes for diagnostic or therapeutic purposes. Assessments of doses to the public, including sewage workers, arising from such discharges are performed. Doses are compared against the exemption level of 10 {mu}Sv/a and the dose constraint of 100 {mu}Sv/a. As a basis for the dose assessments, information on the use of radionuclides in Swedish hospitals during the period 1999-2004 is presented and estimates of discharges to the sewage systems are derived. Current sewage treatment practices in Sweden are summarised focusing particularly on the fate of sewage sludge, both in the sewage plant and outside. Radiological impact assessments are performed in two steps. The assessments in the first stage are performed using a simple screening model, not intending to predict exposures realistically but only to identify exposure pathways and radionuclides that are potentially relevant and require further consideration in the more detailed assessments. Results show that only a few of those radionuclides used in the period 1999-2004 in Swedish hospitals for radiotherapy and radiodiagnostics could lead to potentially significant doses (P-32, Y-90, Tc-99m, In-111, I-123, I-131 and Tl-201). Relevant exposure pathways are the external exposure of sewage workers (for Tc- 99m, I-123, I-131, In-111 and Tl-201) and the exposure of the public via ingestion of water (I-131) and fish (P-32, Y-90 and In-111 and I-131). The objective of the second stage is to perform realistic assessments of the doses to sewage workers and to the public through the use of contaminated agricultural sludge and through the contamination of drinking water. For this purpose, the LUCIA model was developed. This model dynamically addresses the behaviour of radionuclides in the different process steps of a sewage plant. The model can address continuous releases as well

  4. Effect of cycloheximide and actinomycin D on radionuclide 235U-induced apoptosis

    International Nuclear Information System (INIS)

    Fu Qiang; Zhang Lansheng; Zhu Shoupeng

    1999-01-01

    Objective: The mechanism of apoptosis induced by radionuclide 235 U was studied. Methods: MTT and JAM assay were used to analyse the cell viability and quantification of fragmented DNA. Results: The inhibitor of protein cycloheximide (CHX), and the inhibitor of RNA synthesis, actinomycin D. cannot inhibit the apoptosis induced by 235 U, but CHX can partly inhibit apoptotic cells DNA fragmentation. Conclusion: The pathway of apoptosis induced by radionuclide 235 U is different from X-and γ-ray external irradiation, protein synthesis is not essential for it, but synthetic endonuclease is necessary for DNA fragmentation of apoptotic cells

  5. Environmental effects of radionuclides - observations on natural ecosystems

    International Nuclear Information System (INIS)

    Copplestone, D.; Toal, M.E.; Johnson, M.S.; Jackson, D.; Jones, S.R.

    2000-01-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137 Cs, 238 Pu, 239+240 Pu and 241 Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d -1 ) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10 -3 mGy d -1 , 2.2x10 -3 mGy d -1 and 1.0x10 -3 mGy d -1 respectively. The values are at least three orders of magnitude lower than the 1 mGy d -1 level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

  6. Environmental effects of radionuclides--observations on natural ecosystems.

    Science.gov (United States)

    Copplestone, D; Toal, M E; Johnson, M S; Jackson, D; Jones, S R

    2000-03-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137Cs, 238Pu, 239+240Pu and 241Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d(-1)) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0 x 10(-3) mGy d(-1), 2.2 x 10(-3) mGy d(-1) and 1.0 x 10(-3) mGy d(-1) respectively. The values are at least three orders of magnitude lower than the 1 mGy d(-1) level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed.

  7. 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)

  8. Model feasibility study of radioactive pathways from atmosphere to surface water

    International Nuclear Information System (INIS)

    Smith, R.E.; Summer, R.M.; Ferreira, V.A.

    1990-03-01

    A feasibility study of the atmosphere to surface-water radionuclide pathways was performed for small catchments, using a physically-based hydro-ecosystem model, Opus. Detailed time-intensity precipitation records from Arizona and Georgia were used as input to drive the model. Tests of model sensitivity to distribution coefficients, Kd, for Cs-137, Cs-134, and Sr-90 illustrated different vegetation-soil-erosion-runoff pathways, in response to agricultural management practices. Results reflected the fact that low Kd values allow a radionuclide to infiltrate into the soil profile and isolate it from subsequent runoff and erosion. Of the radionuclides and physical settings studied, only the Sr-90, with low Kd values, is sufficiently mobile and long-lived to be removed from the system via percolation below the root zone. Conversely, highly-adsorbed radionuclides were subject to removal by adsorption to sediment particles and subsequent runoff. Comparison of different effective half-lives of I-131 demonstrated the importance of the timing of an erosion-runoff storm event during or immediately after a fallout event. Seasonal timing of a fallout event and crop management also affect the fate of this short-lived radionuclide. Removal by solution to surface-water runoff was negligible for all nuclides studied. 34 refs., 14 figs., 2 tabs

  9. 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

  10. Geologic waste disposal and a model for the surface movement of radionuclides

    International Nuclear Information System (INIS)

    Helton, J.; Iman, R.; Brown, J.; Schreurs, S.

    1979-01-01

    A model for the surface movement of radionuclides is presented. This model, which is referred to as the Pathways Model, was constructed in a NRC project to develop a methodology to assess the risk associated with the goelogic disposal of high-level radioactive waste. The methodology development involves work in two major areas: (a) models for physical processes, and (b) statistical techniques for the use and assessment of these models. The presentation of the Pathways Model involves topics from both areas

  11. Evaluation of radionuclide migration in the homogeneous system of a geological repository

    International Nuclear Information System (INIS)

    Prvakova, S.; Duran, J.; Necas, V.

    2005-01-01

    The aim of this paper is to study radionuclide migration and release from a deep underground repository situated in a clay formation. An insight into the processes influencing the radionuclide transport in the near field and far field will be presented. For the calculation, a set of radionuclides has been chosen, considering the half-life, decay chains, capacity of the sorption, solubility limits and diffusion coefficients. The migration of radionuclides is dependent on transport properties of the particular nuclide. Due to the low hydraulic conductivity of the backfill material and clay geological formation, the transport in the repository occurs mainly by diffusion. The migration rate will be influenced by the water chemistry, solubility, retardation and diffusive properties of the nuclides, and the water flow rate in the clay. The release rates of radionuclides from the geosphere to the biosphere will be converted into the indicative dose rates using dose conversion factors for ingestion. The impact of the critical group is considered via consumption of meat, root vegetables and drinking water from wells. (author)

  12. Safety assessment for deep underground disposal vault-pathways analysis

    International Nuclear Information System (INIS)

    Lyon, R.B.; Rosinger, E.L.J.

    1980-01-01

    The concept verification phase of the Canadian programme for the disposal of nuclear fuel waste encompasses a period of about three years before the start of site selection. During this time, the methodology for Environmental and Safety Assessment studies is being developed by focusing on a model site. Pathways analysis is an important component of these studies. It involves the prediction of the rate at which radionuclides might be released from a disposal vault and travel through the geosphere and biosphere to reach man. The pathways analysis studies cover three major topics: geosphere pathways analysis, biosphere pathways analysis and potentially-disruptive-phenomena analysis. Geosphere pathways analysis includes a total systems analysis, using the computer program GARD2, vault analysis, which considers container failure and waste leaching, hydrogeological modelling and geochemical modelling. Biosphere pathways analysis incorporates a compartmental modelling approach using the computer program RAMM, and a food chain analysis using the computer program FOOD II. Potentially-disruptive-phenomena analysis involves the estimation of the probability and consequences of events such as earthquakes which might reduce the effectiveness of the barriers preventing the release of radionuclides. The current stage of development of the required methodology and data is discussed in each of the three areas and preliminary results are presented. (author)

  13. 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

  14. Model to estimate the local radiation doses to man from the atmospheric release of radionuclides (LWBR development program)

    International Nuclear Information System (INIS)

    Rider, J.L.; Beal, S.K.

    1977-04-01

    A model was developed to estimate the radiation dose commitments received by people in the vicinity of a facility that releases radionuclides into the atmosphere. This model considers dose commitments resulting from immersion in the plume, ingestion of contaminated food, inhalation of gaseous and suspended radioactivity, and exposure to ground deposits. The dose commitments from each of these pathways is explicitly considered for each radionuclide released into the atmosphere and for each daughter of each released nuclide. Using the release rate of only the parent radionuclide, the air and ground concentrations of each daughter are calculated for each position of interest. This is considered to be a significant improvement over other models in which the concentrations of daughter radionuclides must be approximated by separate releases

  15. Half-life data--a critical review of TECDOC-619 update

    International Nuclear Information System (INIS)

    Woods, M.J.; Collins, S.M.

    2004-01-01

    An accurate knowledge of selected nuclear decay data is critical to a wide range of processes involving radionuclides. An IAEA publication in 1991 was dedicated to the evaluation of half-lives and specific gamma-ray emission probabilities for 39 selected radionuclides considered to be important for detector efficiency calibrations. A new exercise was initiated in December 1998 to update this previous evaluation and to include a number of new radionuclides of interest; 62 radionuclides were considered along with specific parent-daughter combinations (to give a total of 64 radionuclides). That work is now being completed and a new set of recommended data is being prepared for publication. A critical comparison of the 1991 and 2003 half-life data suggests that there has not been any significant improvement in the accuracy of the recommended data. The possible reasons for this situation are discussed together with the evaluation procedure and the quality of the available data. Proposals are made for concerted actions that could lead to a significant improvement in these recommended half-life data

  16. Global deposition of fallout radionuclides and their dietary intake

    International Nuclear Information System (INIS)

    Morisawa, Shinsuke

    1993-01-01

    Japanese foods depend largely on foreign countries and domestic food supply now is no more than 30 percents if feedstuffs for live-stocks are included. Therefore not only ecological/natural but also social, e.g., human activities related, transportation of fallout radionuclides are to be taken into accounts for estimation of baseline internal irradiation dose and health risks of Japanese peoples through dietary intake of radionuclides. In this study, mathematical model is developed and examined for practical application on estimating Japanese dietary intake level of fallout strontium-90, which is accumulated in various kinds of foodstuffs and is transported to Japan associated with worldwide trades of foods, under appropriate limitations such that direct deposition on plants and seafood intake pathways are not evaluated. Deposition of strontium-90 onto the surface soil was simulated using the model, the compartment model described by a set ordinary differential equations, and the estimates were examined by comparing them with the observed data colleted and complied by the global scale environmental monitoring networks. Sensitivity analysis is also practised to find possible reduction of dietary intake of fallout radionuclides and the related potential health risks. (author)

  17. Development of computer model for radionuclide released from shallow-land disposal facility

    International Nuclear Information System (INIS)

    Suganda, D.; Sucipta; Sastrowardoyo, P.B.; Eriendi

    1998-01-01

    Development of 1-dimensional computer model for radionuclide release from shallow land disposal facility (SLDF) has been done. This computer model is used for the SLDF facility at PPTA Serpong. The SLDF facility is above 1.8 metres from groundwater and 150 metres from Cisalak river. Numerical method by implicit method of finite difference solution is chosen to predict the migration of radionuclide with any concentration.The migration starts vertically from the bottom of SLDF until the groundwater layer, then horizontally in the groundwater until the critical population group. Radionuclide Cs-137 is chosen as a sample to know its migration. The result of the assessment shows that the SLDF facility at PPTA Serpong has the high safety criteria. (author)

  18. 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

  19. Rest and exercise radionuclide angiography for diagnosis in chronic ischemic heart disease

    International Nuclear Information System (INIS)

    Gibbons, R.J.

    1991-01-01

    Rest and exercise radionuclide angiography is frequently employed for the diagnosis of chest pain syndromes. Its value and limitations in this regard have been well studied, but proper utilization of the technique requires an understanding of five critical concepts: (1) Radionuclide angiography is superior to treadmill exercise testing and probably equivalent to thallium scintigraphy, although the published series did not use current methods. (2) The true specificity of radionuclide angiography is about 80%, intermediate between the early optimistic estimates and the later pessimistic ones. (3) The peak exercise ejection fraction is the preferred test parameter for diagnosis, although exercise hemodynamics, symptoms, and electrocardiographic changes should also be considered. (4) Although radionuclide angiography is clearly helpful for noninvasive diagnosis, significant numbers of patients will continue to fall in an uncertain category. (5) The proper application of the technique requires recognition of its limitations and careful attention to technical details. When properly applied, this modality can make an important contribution to clinical decision making. 58 references

  20. Environmental effects of radionuclides - observations on natural ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Copplestone, D. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom). E-mail: copplest at liv.ac.uk; Toal, M.E.; Johnson, M.S. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom); Jackson, D.; Jones, S.R. [Westlakes Scientific Consulting, Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

    2000-03-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d{sup -1}) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10{sup -3} mGy d{sup -1}, 2.2x10{sup -3} mGy d{sup -1} and 1.0x10{sup -3} mGy d{sup -1} respectively. The values are at least three orders of magnitude lower than the 1 mGy d{sup -1} level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

  1. The sources and fate of radionuclides emitted to the atmosphere

    International Nuclear Information System (INIS)

    Sandalls, J.

    2001-01-01

    The thesis represents an account of the sources and fate of radionuclides entering the atmosphere, and indicates where the candidate, through his own work, has contributed to the overall picture. The sources of the natural and man-made radionuclides found in the atmosphere are identified. New data on emissions from UK coal-fired power stations and UK steel works are reported. Radionuclides produced in nuclear fission and released to the atmosphere in the detonation of nuclear weapons, in nuclear accidents, and through routine discharges from nuclear sites have added to the atmospheric burden of radioactive materials; both acute and chronic low-level emissions are discussed. The various natural processes which remove radionuclides from the atmosphere are described. Soon after release, many radioactive materials become attached to the atmospheric aerosol, but others undergo gas-phase reactions. Some gases are sufficiently long-lived in the troposphere as to find their way into the stratosphere where their fate may be determined by the short-wave radiation from the sun. The nature of the particles of fuel emitted to the atmosphere in the explosion and fire at the Chernobyl nuclear power plant in 1986 are discussed, together with the associated environmental problems. The ground is the major sink for radionuclides leaving the atmosphere, and the behaviour of the more radiologically important radionuclides following deposition is described with special reference to: (i) fallout in both the urban and living environments; (ii) the pathways which may lead to contamination of the food chain; (iii) how the fuel particle fallout from Chernobyl was unique in nuclear accidents; (iv) soil-to-plant transfer of radioelements and (v) how radiation exposure of man can be mitigated in both the contaminated urban and rural environments. (author)

  2. Transfer of radionuclides into and their removal from agricultural products

    Energy Technology Data Exchange (ETDEWEB)

    Hisamatsu, Shun-ichi [Akita Univ. (Japan). School of Medicine; Takizawa, Yukio

    1996-12-31

    Transfer of radionuclides to agricultural products and their removal before ingestion are reviewed briefly. Ingestion of {sup 137}Cs through various food groups were intensively has been studied from 1960s. The results of these studies indicated that cereals were relatively important food groups in Japan, while dairy products were a critical food group in Western countries. However, Westernization of Japanese diet and other factors recently make dairy products more important. In the case of {sup 137}Cs ingestion from the Chernobyl accident, 43% of total {sup 137}Cs intake was ingested through dairy products. The removal of radionuclides from food by washing, preparing and cooking is also discussed. (author)

  3. Historical emissions critical for mapping decarbonization pathways

    Science.gov (United States)

    Majkut, J.; Kopp, R. E.; Sarmiento, J. L.; Oppenheimer, M.

    2016-12-01

    Policymakers have set a goal of limiting temperature increase from human influence on the climate. This motivates the identification of decarbonization pathways to stabilize atmospheric concentrations of CO2. In this context, the future behavior of CO2 sources and sinks define the CO2 emissions necessary to meet warming thresholds with specified probabilities. We adopt a simple model of the atmosphere-land-ocean carbon balance to reflect uncertainty in how natural CO2 sinks will respond to increasing atmospheric CO2 and temperature. Bayesian inversion is used to estimate the probability distributions of selected parameters of the carbon model. Prior probability distributions are chosen to reflect the behavior of CMIP5 models. We then update these prior distributions by running historical simulations of the global carbon cycle and inverting with observationally-based inventories and fluxes of anthropogenic carbon in the ocean and atmosphere. The result is a best-estimate of historical CO2 sources and sinks and a model of how CO2 sources and sinks will vary in the future under various emissions scenarios, with uncertainty. By linking the carbon model to a simple climate model, we calculate emissions pathways and carbon budgets consistent with meeting specific temperature thresholds and identify key factors that contribute to remaining uncertainty. In particular, we show how the assumed history of CO2 emissions from land use change (LUC) critically impacts estimates of the strength of the land CO2 sink via CO2 fertilization. Different estimates of historical LUC emissions taken from the literature lead to significantly different parameterizations of the carbon system. High historical CO2 emissions from LUC lead to a more robust CO2 fertilization effect, significantly lower future atmospheric CO2 concentrations, and an increased amount of CO2 that can be emitted to satisfy temperature stabilization targets. Thus, in our model, historical LUC emissions have a

  4. What is the role of the bystander response in radionuclide therapies?

    Directory of Open Access Journals (Sweden)

    Darren eBrady

    2013-08-01

    Full Text Available Radionuclide therapy for cancer is undergoing a renaissance, with a wide range of radionuclide and clinical delivery systems currently under investigation. Dosimetry at the cellular and subcellular level is complex with inhomogeneity and incomplete targeting of all cells such that some tumour cells will receive little or no direct radiation energy. There is now sufficient preclinical evidence of a bystander response which can modulate the biology of these unirradiated cells with current research demonstrating both protective and inhibitory responses. Dependence upon fraction of irradiated cells has also been found has and the presence of functional gap junctions appears to be import for several bystander responses. The selection of either high or low LET radionuclides may be critical. While low LET radionuclides appear to have a bystander response proportional to dose, the dose-response from high LET radionuclides are more complex. In media transfer experiments a U shaped response curve has been demonstrated for high LET treatments. However this U shaped response has not been seen with co-culture experiments and its relevance remains uncertain. For high LET treatments there is a suggestion that dose rate effects may also be important with inhibitory effects noted with 125I labelling study and a stimulatory seen with 123I labelling in one study.

  5. Radionuclide administration to nursing mothers: mathematically derived guidelines

    International Nuclear Information System (INIS)

    Romney, B.M.; Nickoloff, E.L.; Esser, P.D.; Alderson, P.O.

    1986-01-01

    We determined a formula to establish objective guidelines for the administration of radionuclides to nursing mothers. The formula is based on the maximum permissible dose to the infant's critical organ, serial measurements of breast milk activity, milk volume, and dose to the critical organ per microcurie in milk. Using worst-case assumptions, we believe that cessation of nursing for 24 hours after administration of technetium labeled radiopharmaceuticals is sufficient for safety. Longer-lived agents require greater delays. Iodine-123 radiopharmaceuticals are preferable to iodine-131 agents and should always be used when studying the unblocked thyroid

  6. Human radiation dose resulting from forests contaminated by radionuclides: generic model and applications to the Chernobyl ecosystems

    International Nuclear Information System (INIS)

    Linkov, I.; Harvard Univ., Cambridge, MA; Schell, W.R.

    1996-01-01

    Forest ecosystems have been found to contribute significantly to the human radiation dose in the intermediate and long teens following radionuclide releases. Evaluation of the internal and external radiation dose for these critical population groups requires knowledge of radionuclide transport processes in forest ecosystems, as well as the extent of forest utilization by these populations. The high complexity of the problem requires the use of models to define and analyze the properties of the forest as well as to evaluate the ecosystem response to possible human intervention. A generic FORESTPATH model is used to calculate the internal and external radiation doses for different critical groups of consumers at different times following radionuclide release. The model is tested using the information available for contaminated forests in Belarus. Uncertainty of the model predictions are estimated by means of Monte-Carlo simulations. (author)

  7. ALMERA Proficiency Test: Determination of Gamma Emitting Radionuclides in Simulated Air Filters

    International Nuclear Information System (INIS)

    2010-01-01

    The activity concentration of radionuclides in air is a critical factor in assessing the air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to radioactivity. Radioactivity may be present in the atmosphere due to natural processes; intentional (low level) anthropogenic release; or as a consequence of nuclear or radiological incident. The resulting environmental impact should be considered carefully to ensure safety and compliance with environmental regulations. A reliable determination of radionuclides in air is necessary for regular monitoring of air quality to comply with radiation protection and environmental regulations. This proficiency test (PT) is one of the series of the ALMERA network proficiency tests organised on regular basis by the Terrestrial Environment Laboratory in Seibersdorf, designed to assess the technical capacity of ALMERA Members in analysing radionuclides to identify any analytical problems and to support ALMERA laboratories to maintain their preparedness to provide rapid and reliable analytical results. The range of simulated air filters used in this PT for analysis has been mainly at environmental level. The PT set consisted of four filters. The participating laboratories were requested to analyze Mn-54, Co-57, Fe-59, Co-60, Zn-65, Cd-109, Ba-133, Cs-134, Cs-137, Eu-152 and Am-241 in filters 01, 02 and 03. The participants were informed that only some of the listed radionuclides were present in the filters and the levels of the radionuclides were such that they could be measured within a 6-hour measurement period using a conventional HPGe gammaspectrometer of 35% relative efficiency. Filter 04, was containing only Co-60 and Ba-133 with known activities to the participants, had to be used as a control for the efficiency calibration. The tasks of IAEA were to prepare and distribute the simulated air filters to the participating laboratories, to collect and interpret

  8. Methods of assessing total doses integrated across pathways

    International Nuclear Information System (INIS)

    Grzechnik, M.; Camplin, W.; Clyne, F.; Allott, R.; Webbe-Wood, D.

    2006-01-01

    Calculated doses for comparison with limits resulting from discharges into the environment should be summed across all relevant pathways and food groups to ensure adequate protection. Current methodology for assessments used in the radioactivity in Food and the Environment (R.I.F.E.) reports separate doses from pathways related to liquid discharges of radioactivity to the environment from those due to gaseous releases. Surveys of local inhabitant food consumption and occupancy rates are conducted in the vicinity of nuclear sites. Information has been recorded in an integrated way, such that the data for each individual is recorded for all pathways of interest. These can include consumption of foods, such as fish, crustaceans, molluscs, fruit and vegetables, milk and meats. Occupancy times over beach sediments and time spent in close proximity to the site is also recorded for inclusion of external and inhalation radiation dose pathways. The integrated habits survey data may be combined with monitored environmental radionuclide concentrations to calculate total dose. The criteria for successful adoption of a method for this calculation were: Reproducibility can others easily use the approach and reassess doses? Rigour and realism how good is the match with reality?Transparency a measure of the ease with which others can understand how the calculations are performed and what they mean. Homogeneity is the group receiving the dose relatively homogeneous with respect to age, diet and those aspects that affect the dose received? Five methods of total dose calculation were compared and ranked according to their suitability. Each method was labelled (A to E) and given a short, relevant name for identification. The methods are described below; A) Individual doses to individuals are calculated and critical group selection is dependent on dose received. B) Individual Plus As in A, but consumption and occupancy rates for high dose is used to derive rates for application in

  9. Radionuclide generators

    International Nuclear Information System (INIS)

    Lambrecht, R.M.; Wollongong Univ.; Tomiyoshi, K.; Sekine, T.

    1997-01-01

    The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radio-immunotherapeutic pharmaceuticals: and advances with ultra-short lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent: and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn → 62 Cu, 66 Ni → 66 Cu, 103m Rh → 103 Rh, 188 W → 188 Re and the 225 Ac → 221 Fr → 213 Bi generators are predicted to be emphasized for future development. Coverage of the 99 Mo → 99m Tc generator was excluded, as it the subject of another review. The literature search ended June, 1996. (orig.)

  10. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2009

    International Nuclear Information System (INIS)

    2010-01-01

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office operates the Nevada Test Site (NTS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NTS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NTS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NTS. After nuclear testing ended in 1992, NTS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of tritium were also emitted to air at the NLVF, an NTS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy facility to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation not related to NTS activities. Unrelated doses could come from naturally occurring radioactive elements or from sources such as medically or commercially used radionuclides. The NTS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the sole method used since 2005. Six locations on the NTS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo-critical receptor stations, because no

  11. Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum

    International Nuclear Information System (INIS)

    Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

    1980-01-01

    Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes

  12. Mediterranean Region proficiency test on the determination of radionuclides in air filters. IAEA-CU--2008-02

    International Nuclear Information System (INIS)

    2009-01-01

    The IAEA helps the Member States laboratories to maintain their readiness and improving the quality of the analytical results by producing reference materials, by development of standardized methods for sample collection and analysis, and by conducting interlaboratory comparisons and proficiency tests as a tool for external quality control of analytical results. The Chemistry Unit of the Physics, Chemistry and Instrumentation Laboratory in the International Atomic Energy Agency's Seibersdorf Laboratories in Austria, has the programmatic responsibility to support global radionuclide measurement systems. To fulfil this obligation and ensure a reliable worldwide, rapid and consistent response, the Chemistry Unit organises interlaboratory studies and proficiency tests. The activity concentration of radionuclides in the air is a critical factor in assessing the air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to pollutants. Radioactivity may be present in the atmosphere due to natural processes; intentional (low level) anthropogenic release; or as a consequence of nuclear or radiological incident. Within the frame of the IAEA Technical Cooperation project RER/8/009 'Air Pollution Monitoring in the Mediterranean Region', several Member States expressed their interest in establishing close cooperation among Mediterranean countries in the field of harmonization of air pollution monitoring systems and creation of a common database, since they share geographical position and mutual interest in the environmental conditions of the Mediterranean region. Such cooperation will also promote and enhance the exchange of experience/information. This report summarizes the results of the IAEA-CU-2008-02 Mediterranean Region proficiency test on the determination of radionuclides in air filters

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

    International Nuclear Information System (INIS)

    Gaefvert, T.; Holm, E.

    2002-01-01

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

  14. Monte Carlo simulation of age-dependent radiation dose from alpha- and beta-emitting radionuclides to critical trabecular bone and bone marrow targets

    Science.gov (United States)

    Dant, James T.; Richardson, Richard B.; Nie, Linda H.

    2013-05-01

    Alpha (α) particles and low-energy beta (β) particles present minimal risk for external exposure. While these particles can induce leukemia and bone cancer due to internal exposure, they can also be beneficial for targeted radiation therapies. In this paper, a trabecular bone model is presented to investigate the radiation dose from bone- and marrow-seeking α and β emitters to different critical compartments (targets) of trabecular bone for different age groups. Two main issues are addressed with Monte Carlo simulations. The first is the absorption fractions (AFs) from bone and marrow to critical targets within the bone for different age groups. The other issue is the application of 223Ra for the radiotherapy treatment of bone metastases. Both a static model and a simulated bone remodeling process are established for trabecular bone. The results show significantly lower AFs from radionuclide sources in the bone volume to the peripheral marrow and the haematopoietic marrow for adults than for newborns and children. The AFs from sources on the bone surface and in the bone marrow to peripheral marrow and haematopoietic marrow also varies for adults and children depending on the energy of the particles. Regarding the use of 223Ra as a radionuclide for the radiotherapy of bone metastases, the simulations show a significantly higher dose from 223Ra and its progeny in forming bone to the target compartment of bone metastases than that from two other more commonly used β-emitting radiopharmaceuticals, 153Sm and 89Sr. There is also a slightly lower dose from 223Ra in forming bone to haematopoietic marrow than that from 153Sm and 89Sr. These results indicate a higher therapy efficiency and lower marrow toxicity from 223Ra and its progeny. In conclusion, age-related changes in bone dimension and cellularity seem to significantly affect the internal dose from α and β emitters in the bone and marrow to critical targets, and 223Ra may be a more efficient

  15. Decision analysis of countermeasures for the milk pathway after an accidental release of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, M.; Sinkko, K.; Kostiainen, E.; Salo, E.; Liskola, K.; Haemaelaeinen, R.P.; Mustajoki, J

    2001-12-01

    A facilitated workshop was arranged to plan countermeasures that could reduce the dose arising from the consumption of radionuclide-contaminated milk products. It was assumed that a hypothetical accident in a nuclear facility had led to the release of considerable amounts of radionuclides, which subsequently spread across one of Finland's most important agricultural regions and contaminated the milk produced there. The participants in the workshop, interest groups on food issues, considered all the factors influencing the countermeasure decision, not only radiological or monetary ones but less tangible psychosocial effects as well. The participants preferred the countermeasures provision of uncontaminated fodder and production control to banning and disposal. The analysis showed that these countermeasures could be implemented even if the radionuclide concentrations in foodstuffs were below internationally recommended intervention levels. Banning and withdrawal of milk products from sale was not a favourable option, because of the high costs and disadvantages to producers and the industry, and because the disposal of enormous amounts of milk causes a considerable environmental problem. The study revealed the need to further develop methods to realistically assess the radiological and cost implications of food countermeasures. The feasibility and constraints of actions also need further investigation. The experience gained strongly supports the format of a facilitated workshop to tackle a decision problem that concerns different stakeholders. The participants considered the workshop and the decision analysis very useful in exercises. They also expected a similar approach to be applicable in a real situation, although the suitability was not rated as high as for exercises. It is concluded that a facilitated workshop is a valuable instrument for emergency management and in exercises, when revising emergency plans or in order to identify issues that need to be

  16. 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.)

  17. Deduction and Analysis of the Interacting Stress Response Pathways of Metal/Radionuclide-reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jizhong [University of Oklahoma; He, Zhili [University of Oklahoma

    2010-02-28

    Project Title: Deduction and Analysis of the Interacting Stress Response Pathways of Metal/Radionuclide-reducing Bacteria DOE Grant Number: DE-FG02-06ER64205 Principal Investigator: Jizhong (Joe) Zhou (University of Oklahoma) Key members: Zhili He, Aifen Zhou, Christopher Hemme, Joy Van Nostrand, Ye Deng, and Qichao Tu Collaborators: Terry Hazen, Judy Wall, Adam Arkin, Matthew Fields, Aindrila Mukhopadhyay, and David Stahl Summary Three major objectives have been conducted in the Zhou group at the University of Oklahoma (OU): (i) understanding of gene function, regulation, network and evolution of Desulfovibrio vugaris Hildenborough in response to environmental stresses, (ii) development of metagenomics technologies for microbial community analysis, and (iii) functional characterization of microbial communities with metagenomic approaches. In the past a few years, we characterized four CRP/FNR regulators, sequenced ancestor and evolved D. vulgaris strains, and functionally analyzed those mutated genes identified in salt-adapted strains. Also, a new version of GeoChip 4.0 has been developed, which also includes stress response genes (StressChip), and a random matrix theory-based conceptual framework for identifying functional molecular ecological networks has been developed with the high throughput functional gene array hybridization data as well as pyrosequencing data from 16S rRNA genes. In addition, GeoChip and sequencing technologies as well as network analysis approaches have been used to analyze microbial communities from different habitats. Those studies provide a comprehensive understanding of gene function, regulation, network, and evolution in D. vulgaris, and microbial community diversity, composition and structure as well as their linkages with environmental factors and ecosystem functioning, which has resulted in more than 60 publications.

  18. Radionuclide data

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Chapter 8 presents tables on selected alpha, beta, gamma and x-ray emitters by increasing energy; information on specific activity for selected radionuclides; naturally occurring radionuclides; the natural decay series; and the artificially produced neptunium series. A table of alpha emitters is listed by increasing atomic number and by energy. The table of β emitters presented is useful in identifying β emitters whose energies and possibly half-lives have been determined by standard laboratory techniques. It is also a handy guide to β-emitting isotopes for applications requiring specific half-lives and/or energies. Gamma rays for radionuclides of importance to radiological assessments and radiation protection are listed by increasing energy. The energies and branching ratios are important for radionuclide determinations with gamma spectrometry detectors. This section also presents a table of x-ray energies which are useful for radiochemical analyses. A number of nuclides emit x-rays as part of their decay scheme. These x-rays may be counted with Ar proportional counters, Ge planar or n-type Ge co-axial detectors, or thin crystal NaI(T1) scintillation counters. In both cases, spectral measurements can be made and both qualitative and quantitative information obtained on the sample. Nuclear decay data (energy and probability by radiation type) for more than one hundred radionuclides that are important to health physicists are presented in a schematic manner

  19. Modelling of radionuclide migration in forest ecosystems. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Avila, R.; Moberg, L.; Hubbard, L.

    1998-03-01

    The Chernobyl accident has clearly shown the long-term effects of a radioactive contamination of forest ecosystems. This report is based on a literature review of models which describe the migration of radionuclides, radioactive caesium in particular, in forest ecosystems. The report describes the particularities of the forest ecosystem, the time dynamics of the contamination, the transfer processes and factors influencing caesium migration. This provides a basis for a discussion of different approaches for modelling caesium migration in the forest. It is concluded that the studied dynamic models include the most relevant transfer processes both for the acute and the long-term phase after a radioactive deposition. However, most models are site specific and do not consider some of the factors responsible for the differences in radionuclide behaviour and distribution in different types of forests. Although model improvements are constrained by the availability of experimental data and by the lack of knowledge of the migration mechanisms some possible improvements are discussed. This report is part of the LANDSCAPE project. -An integrated approach to radionuclide flow in the semi-natural ecosystems underlying exposure pathways to man. 42 refs, 3 tabs, 9 figs.

  20. Modelling of radionuclide migration in forest ecosystems. A literature review

    International Nuclear Information System (INIS)

    Avila, R.; Moberg, L.; Hubbard, L.

    1998-03-01

    The Chernobyl accident has clearly shown the long-term effects of a radioactive contamination of forest ecosystems. This report is based on a literature review of models which describe the migration of radionuclides, radioactive caesium in particular, in forest ecosystems. The report describes the particularities of the forest ecosystem, the time dynamics of the contamination, the transfer processes and factors influencing caesium migration. This provides a basis for a discussion of different approaches for modelling caesium migration in the forest. It is concluded that the studied dynamic models include the most relevant transfer processes both for the acute and the long-term phase after a radioactive deposition. However, most models are site specific and do not consider some of the factors responsible for the differences in radionuclide behaviour and distribution in different types of forests. Although model improvements are constrained by the availability of experimental data and by the lack of knowledge of the migration mechanisms some possible improvements are discussed. This report is part of the LANDSCAPE project. -An integrated approach to radionuclide flow in the semi-natural ecosystems underlying exposure pathways to man

  1. Integrated report on radionuclide migration at the Savannah River shallow land burial site

    International Nuclear Information System (INIS)

    Towler, O.A. Jr.

    1989-03-01

    The impact of the SRP Solid Radioactive Waste Burial Ground on the environment has been studied since the early 1970s in four subtasks: subsurface monitoring of groundwater, lysimeter tests of waste, soil-water chemistry effects, and radionuclide transport modeling. This document summarizes and integrates the results of the four subtasks. More information has been gathered on the behavior of radionuclides in a solid waste disposal facility located in a humid region than from any other waste disposal site in the world. The design of closure for the SRP Burial Ground has been given a firm technical basis. The limiting pathways for radionuclide migration have been determined to be infiltrating rainwater and root penetration. Closure designs must therefore address both these factors. The designs for new storage/disposal facilities have also been given a firm technical basis. The major conclusions are that tritium will be stored for decay and not allowed to contact the groundwater, waste containing long-lived radionuclides such as iodine-129 must be stored for later geologic disposal, and above and below ground concrete vaults should be used for disposal of other low-level radioactive waste. 61 refs., 18 figs. 8 tabs

  2. Consideration for modelling studies of migration of accidentally released radionuclides in a river watershed

    International Nuclear Information System (INIS)

    Matsunaga, Takeshi; Tsuduki, Katsunori; Yanase, Nobuyuki; Hanzawa, Yukiko; Ueno, Takashi

    2004-01-01

    Concerning radionuclides that might be released in an event of an accident from a nuclear facility, much attention has been paid to the migration pathways including the atmospheric deposition and subsequent inflow to surface water bodies since the Chernobyl nuclear accident in 1986. In European countries, computer-coded systems for predicting the migration including those pathways and providing scientific supports for decision makers to manage the contamination have been developed. This report is a summary of presentations and discussion made at the occasion of the visit of Dr. Monte in order to have directions related to the current subject of research, development of a mathematical model of the behavior of radionuclides in a river watershed. Those presentations and discussions were made at JAERI and also at prominent universities and institutes of Japan involved in this study field. As a result of these discussions, distinct advantages and key issues in use of a mathematical model for prediction of the migration of radionuclides in a river watershed have been identified and analyzed. It was confirmed that the use of mathematical modeling has distinct advantages. Re-arrangement of the existing experimental knowledge on the environment in an ordered way according to a theory (a mathematical model) will lead to a new angle to consider a problem in that environment, despite several gaps in the data array. A model to assess the radionuclide behaviour in contaminated aquatic ecosystems is a basis of decision analysis tools for helping decision-makers to select the most appropriate intervention strategies for the ecosystems. Practical use of a mathematical model and continuous effort in its validation were recognized as crucial. (author)

  3. Radionuclide generators

    International Nuclear Information System (INIS)

    Lambrecht, R.M.

    1983-01-01

    The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

  4. Collection and preparation of marine samples for radionuclide analysis

    International Nuclear Information System (INIS)

    Holm, E.

    1997-01-01

    The ultimate goal of research in radioecology is to be able to predict the pathways of radioactive material in the environment and hence estimate possible doses to the population in various regions. Knowledge of levels of contamination are necessary to maintain control of operations of nuclear facilities. Correct methods of sample collection, handling and preparation are among the most important parts for a correct assessment. On basis of the final results of radionuclide concentrations, scientific, medical and political decisions are taken. (author)

  5. Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

    International Nuclear Information System (INIS)

    Gibson, J.A.B.; Wrixon, A.D.

    1979-01-01

    Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

  6. Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

    Science.gov (United States)

    Widel, M

    2017-01-01

    For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

  7. Review and assessment of models for predicting the migration of radionuclides through rivers

    International Nuclear Information System (INIS)

    Monte, Luigi; Boyer, Patrick; Brittain, John E.; Haakanson, Lars; Lepicard, Samuel; Smith, Jim T.

    2005-01-01

    The present paper summarises the results of the review and assessment of state-of-the-art models developed for predicting the migration of radionuclides through rivers. The different approaches of the models to predict the behaviour of radionuclides in lotic ecosystems are presented and compared. The models were classified and evaluated according to their main methodological approaches. The results of an exercise of model application to specific contamination scenarios aimed at assessing and comparing the model performances were described. A critical evaluation and analysis of the uncertainty of the models was carried out. The main factors influencing the inherent uncertainty of the models, such as the incompleteness of the actual knowledge and the intrinsic environmental and biological variability of the processes controlling the behaviour of radionuclides in rivers, are analysed

  8. Soil-to-plant transfer factors of stable elements and naturally occurring radionuclides. (2) Rice collected in Japan

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Tagami, Keiko; Hirai, Ikuko

    2007-01-01

    The critical paths of radionuclides and the critical foods in Japan are different from those in European and North American countries because agricultural products and food customs are different. Consequently, safety assessment in Japan is required to consider rice and vegetables as the critical foods. In this study, we measured soil-to-plant transfer factors (TFs) for rice using naturally existing elements as analogues of radionuclides under equilibrium conditions. Rice and associated soil samples were collected from 50 sampling sites throughout Japan and TFs of 36 and 34 elements for brown rice and white rice, respectively, were calculated on dry weight basis. Probability distributions of TFs of elements for brown rice and white rice were a log normal type. Except for As and Mo, the TFs for brown rice were usually lower than those for wheat and barley especially for K, Fe, Sr (t-test: p 90 Sr and 137 Cs observed in field experiments. Thus, the TFs of naturally existing elements can be used as TFs of those radionuclides which have been in contact with the environment for a long time and have reached equilibrium conditions. (author)

  9. Paving the way to personalized medicine. Production of some theragnostic radionuclides at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Srivastava, S.C.

    2011-01-01

    This paper introduces a relatively novel paradigm that involves specific individual radionuclides or radionuclide pairs that have emissions that allow pre-therapy low-dose imaging plus higher-dose therapy in the same patient. We have made an attempt to sort out and organize a number of such theragnostic radionuclides and radionuclide pairs that may potentially bring us closer to the age-long dream of personalized medicine for performing tailored low-dose molecular imaging (SPECT/CT or PET/CT) to provide the necessary pre-therapy information on biodistribution, dosimetry, the limiting or critical organ or tissue, and the maximum tolerated dose (MTD), etc. If the imaging results then warrant it, it would be possible to perform higher-dose targeted molecular therapy in the same patient with the same radiopharmaceutical. A major problem that remains yet to be fully resolved is the lack of availability, in sufficient quantities, of a majority of the best candidate theragnostic radionuclides in a no-carrier-added (NCA) form. A brief description of the recently developed new or modified methods at BNL for the production of four theragnostic radionuclides, whose nuclear, physical, and chemical characteristics seem to show great promise for personalized cancer therapy are described.

  10. 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

  11. Radionuclide scanning

    International Nuclear Information System (INIS)

    Shapiro, B.

    1986-01-01

    Radionuclide scanning is the production of images of normal and diseased tissues and organs by means of the gamma-ray emissions from radiopharmaceutical agents having specific distributions in the body. The gamma rays are detected at the body surface by a variety of instruments that convert the invisible rays into visible patterns representing the distribution of the radionuclide in the body. The patterns, or images, obtained can be interpreted to provide or to aid diagnoses, to follow the course of disease, and to monitor the management of various illnesses. Scanning is a sensitive technique, but its specificity may be low when interpreted alone. To be used most successfully, radionuclide scanning must be interpreted in conjunction with other techniques, such as bone radiographs with bone scans, chest radiographs with lung scans, and ultrasonic studies with thyroid scans. Interpretation is also enhanced by providing pertinent clinical information because the distribution of radiopharmaceutical agents can be altered by drugs and by various procedures besides physiologic and pathologic conditions. Discussion of the patient with the radionuclide scanning specialist prior to the study and review of the results with that specialist after the study are beneficial

  12. Health impacts of large releases of radionuclides. Proceedings

    International Nuclear Information System (INIS)

    Lake, J.V.; Bock, G.R.; Cardew, Gail

    1997-01-01

    There have been various large-scale releases of radionuclides into the environment in the 20th century. Some of these have been accidental and some deliberate. In order to minimize the risk to human health of such releases, it is important that we understand how these substances are transported throughout the terrestrial and aquatic environments and the ways in which they can ultimately affect human health. This book contains contributions from the world's leading radioecologists and health scientists who discuss the progress in understanding these transport processes and exposure pathways of radionuclides to humans; the problems and latest techniques of quantitating retrospectively the actual doses received by individuals; the time course of effects of exposure in relation to structure and function at the cellular tissue, organ and whole organism level; the genetic effects, and effects on reproductive health, in populations and individuals, including fetal effects in pregnant women and inherited genetic effects; and scientific approaches to evaluate the important problem of the mental health consequences of perceived risk of radiation damage to health. (author)

  13. A study on the radionuclide transport through fractured porous media based on the network resistance model

    International Nuclear Information System (INIS)

    Hwang, Ki Ha

    2000-02-01

    Before the actual construction of radioactive waste repository, analysis of radionuclide transport is required to predict the radiological effect on public and environment. Many models have been developed to predict the realistic radionuclide transport through the repository. In this study, Network Resistance Model (NRM) that is similar to electrical circuit network is adopted to simulate the radionuclide transport. NRM assume the media of repository as the resistance of the radionuclide transport and describes the transport phenomena of radionuclide by connecting the resistance as network. NRM is easy to apply to describe complex system and take less calculation time compared to the other model. The object of this study is to develop the fast, simple and efficient calculation method to simulate the radionuclide with the newly adopted concept using network resistance. New system configuration specially focused on rock edge region is introduced by dividing the rock matrix. By dividing the rock edge from the main rock matrix region, the rock edge region is more carefully analyzed and compared. Rock edge region can accelerate radionuclide transport due to the reducing effect on the total resistivity of rock matrix. Therefore, increased radioactive dose is expected when we apply NRM methodology in the performance assessment of the repository. Result of the performance assessment can be more conservative and reliable. NRM can be applied to other system configuration and for more complex pathways. NRM is simple to us e and easy to modify than any other modeling method

  14. Environmental pathways of radioactivity to man

    International Nuclear Information System (INIS)

    Johns, T.F.

    1979-12-01

    The report reviews and discusses the environmental pathways by which radioactive materials can lead to the irradiation of man, in a way that should be understood by non-specialists who have neither the time nor the knowledge to study all of the relevant literature on this subject. The role of these environmental pathways in the general structure of radiological protection is considered, and the various mechanisms which lead to the dispersion or re-concentration of radioactive materials are discussed at some length. Particular groups of radionuclides from the nuclear power industry are considered in some detail. Similarly the question of the corresponding pathways from naturally-occurring radioactive materials is covered. The doses to animals and plants resulting from the nuclear industry are examined, and it is concluded that there is no reason to expect that these doses will lead to significant harm. Finally a summary is presented, and it is noted that it has been possible to obtain a very extensive knowledge of the behaviour of radionuclides in the environment only because of the extreme sensitivity of the techniques available for their detection, identification and assay. As a result a fund of knowledge has been built up about the behaviour of radioactive materials in the environment which is far more extensive than our knowledge of the behaviour of many highly toxic chemicals which are also discharged into the environment. (UK)

  15. Drift-Scale Radionuclide Transport

    International Nuclear Information System (INIS)

    Houseworth, J.

    2004-01-01

    The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

  16. MARFA version 3.2.2 user's manual: migration analysis of radionuclides in the far field

    International Nuclear Information System (INIS)

    Painter, Scott; Mancillas, James

    2009-12-01

    The computer code Migration Analysis of Radionuclides in the Far Field (MARFA) uses a particle-based Monte Carlo method to simulate the transport of radionuclides in a sparsely fractured geological medium. Transport in sparsely fractured rock is of interest because this medium may serve as a barrier to migration of radionuclides to the accessible environment. The physical processes represented in MARFA include advection, longitudinal dispersion, Fickian diffusion into an infinite or finite rock matrix, equilibrium sorption, decay, and in-growth. Multiple non-branching decay chains of arbitrary length are supported. This document describes the technical basis and input requirements for MARFA Version 3.2.2. MARFA Version 3.2 included new capabilities to accommodate transient flow velocities and sorption parameters, which are assumed to be piecewise constant in time. Version 3.2.1 was a minor change from Version 3.2 to allow a more convenient input format for sorption information. New capabilities in Version 3.2.2 include an option to specify a non-zero start time for the simulation, an optional input parameter that decreases the amount of retention within a single fracture because of flow channeling, and an alternative method for sampling the radionuclide source. MARFA uses the particle on random streamline segment algorithm /Painter et al. 2006/, a Monte Carlo algorithm combining time-domain random walk methods with pathway stochastic simulation. The algorithm uses non-interacting particles to represent packets of radionuclide mass. These particles are moved through the system according to rules that mimic the underlying physical transport and retention processes. The set of times required for particles to pass through the geological barrier are then used to reconstruct discharge rates (mass or activity basis). Because the algorithm uses non-interacting particles, the transport and retention processes are limited to those that depend linearly on radionuclide

  17. Chapter 2. Radionuclides in the biosphere

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with role of radionuclides in the biosphere. Chapter consists of next parts: (1) Natural radionuclides in biosphere; (2) Man-made radionuclides in the biosphere; (3) Ecologically important radionuclides; (4) Natural background; (5) Radiotoxicity and (6) Paths of transfer of radionuclides from the source to human

  18. Modelling and analysis of radionuclide dispersion from PWR on abnormal condition in Bojanegara Serang site

    International Nuclear Information System (INIS)

    Sri Kuntjoro

    2010-01-01

    Additional of electrical power especially Nuclear Power Plant will give radiological consequence sto population and environment due to radioactive release in normal and abnormal condition. In consequence the management of nuclear power plant must supply data and strong argumentation to clarify the safety of nuclear power plant to environment. For that purpose it needs to be carried out an analysis of abnormal condition in nuclear power plant and its radiological consequences to the environment. That analysis is done using abnormal condition simulation model postulated on 1000 MWe nuclear power plant.That simulation model is used also to evaluate environmental potential as site capability in supporting the radiological consequences. Radionuclide transport modeling from reactor core to containment uses EMERALD computer code. Other computer codes are Wind rose, PC-COSYMA and Arc View are used to simulate meteorology condition, radionuclide release to population distribution of food production and consumption and distribution of radiation dose received to population around nuclear power plant. Application of that simulation is carried out to NPP candidate site in Bojanegara-Kramatwatu, Serang Banten peninsula. Using source term data, meteorology data, dispersion data and pathways modeling are resulting radionuclide dispersion model and radiation pathway acceptance at the surrounding nuclear power plant site (Bojanegara-Serang peninsula). The result shows that maximum radiation dose received is lower than dose permitted in accordance with regulatory body (BAPETEN). (author)

  19. The history of critical group doses from the consumption of freshwater fish at Trawsfynydd, North Wales

    International Nuclear Information System (INIS)

    Leonard, D.R.P.

    1992-01-01

    Radionuclides discharged into the aquatic environment from Trawsfynydd power station are, as for all UK facilities, subject to statutory controls to ensure that the resulting public radiation exposure complies with nationally-accepted criteria. Environmental monitoring by MAFF has shown that near this facility the consumption of freshwater fish is radiologically the most important pathway with Cs-137 the dominant radionuclide. Information gathered from consumers over a twenty-five year period has been interpreted so as to derive doses to the public. Committed effective doses (CEDs) are presented using ICRP 1990 methodology and compared with the recommended dose limit of 1 mSv year -1 . Doses to the critical group are shown to have exceeded 1 mSv year -1 for two years but do not exceed this limit when averaged over a period of 5 years. Because of the changing habits of the consumers it is suggested that the average annual CED over the lifetime of any member of the public will not exceed 1 mSv year -1 during the operation of the station. (author)

  20. RADBASE: A PC-based radionuclide data base for environmental site assessment

    International Nuclear Information System (INIS)

    Dundon, S.T.; Heger, A.S.

    1992-01-01

    A personal computer-based code, RADBASE, is being developed as a tool for reviewing environmental risk data. RADBASE has been designed to display the properties of radionuclides encountered in environmental restoration programs. The code contains five major features that display (a) physical properties, (b) pathways and toxicity data, (c) means of production and common uses, (d) federal radiation protection standards and action levels, and (e) bibliographic information. The benefits of the radionuclide data base contained in this code include time efficiency and update capability. This code separates itself from similar codes on the basis of its interactive data files, windows environment, and content. The user must only be equipped with basic information on a site and possess a minimum amount of user knowledge to operate and access additional data applicable to the constituents at the site

  1. Influence of fracture networks on radionuclide transport from solidified waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Seetharam, S.C., E-mail: suresh.seetharam@sckcen.be [Performance Assessments Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, B-2400 Mol (Belgium); Perko, J.; Jacques, D. [Performance Assessments Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, B-2400 Mol (Belgium); Mallants, D. [CSIRO Land and Water, Waite Road – Gate 4, Glen Osmond, SA 5064 (Australia)

    2014-04-01

    investigated system, radionuclide properties and the imposed water flow boundary conditions, results demonstrate that: (i) magnitude of peak radionuclide fluxes is less sensitive to the fracture network geometry, (ii) timing of the peak radionuclide fluxes is possibly sensitive to the fracture networks, (iii) a uniform flow model represents a limiting case of a porous medium with large number of fine fractures, (iv) the effect of fracture width on the radionuclide flux depends on the ratio of fracture to matrix conductivity and is less sensitive if the ratio is large and the width is higher than a certain critical size, and (v) increased dispersivity in fractured media influences the transport behaviour differently compared to non-fractured media; in particular, the behaviour depends on the nature of fracture network.

  2. Influence of fracture networks on radionuclide transport from solidified waste forms

    International Nuclear Information System (INIS)

    Seetharam, S.C.; Perko, J.; Jacques, D.; Mallants, D.

    2014-01-01

    investigated system, radionuclide properties and the imposed water flow boundary conditions, results demonstrate that: (i) magnitude of peak radionuclide fluxes is less sensitive to the fracture network geometry, (ii) timing of the peak radionuclide fluxes is possibly sensitive to the fracture networks, (iii) a uniform flow model represents a limiting case of a porous medium with large number of fine fractures, (iv) the effect of fracture width on the radionuclide flux depends on the ratio of fracture to matrix conductivity and is less sensitive if the ratio is large and the width is higher than a certain critical size, and (v) increased dispersivity in fractured media influences the transport behaviour differently compared to non-fractured media; in particular, the behaviour depends on the nature of fracture network

  3. Effect of Concrete Waste Form Properties on Radionuclide Migration

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Skinner, De'Chauna J.; Cordova, Elsa A.; Wood, Marcus I.

    2009-01-01

    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 waste form performance is affected by the full range of environmental conditions within the disposal facility, the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility, the effect of waste form 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 waste forms come in contact with groundwater. Numerous sets of tests were initiated in fiscal years (FY) 2006-2009 to evaluate (1) diffusion of iodine (I) and technetium (Tc) from concrete into uncontaminated soil after 1 and 2 years, (2) I and rhenium (Re) diffusion from contaminated soil into fractured concrete, (3) I and Re (set 1) and Tc (set 2) diffusion from fractured concrete into uncontaminated soil, (4) evaluate the moisture distribution profile within the sediment half-cell, (5) the reactivity and speciation of uranium (VI) (U(VI)) compounds in concrete porewaters, (6) the rate of dissolution of concrete monoliths, and (7) the diffusion of simulated tank waste into concrete.

  4. 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

  5. Rancho Seco liquid effluent pathway aquatic and terrestrial dietary survey report

    International Nuclear Information System (INIS)

    Eagle, R.J.; Wong, K.M.; Noshkin, V.E.

    1984-01-01

    This report is a detailed summary of a survey conducted to identify all environmental pathways that may lead to any potential radiological dose to individuals utilizing aquatic and terrestrial components possibly contaminated with radionuclides contained in the liquid effluents that have been routinely discharged since 1980 to Clay Creek from the Rancho Seco Nuclear Generating Station. All land users and identified residents who obtain food from the creeks or use the creek water for irrigation or recreation were interviewed. Site specific usage parameters for the consumption of different food products and for direct exposure to individuals at downstream locations were identified and are discussed in this report. These usage parameters will be used with appropriate radionuclide concentration data to estimate radiological dose to man from the identified liquid effluent pathways

  6. Application od scaling technique for estimation of radionuclide inventory in radioactive waste

    International Nuclear Information System (INIS)

    Hertelendi, E.; Szuecs, Z.; Gulyas, J.; Svingor, E.; Csongor, J.; Ormai, P.; Fritz, A.; Solymosi, J.; Gresits, I.; Vajda, N.; Molnar, Zs.

    1996-01-01

    Safety studies related to the disposal of low- and intermediate waste indicate that the long term risk is determined by the presence of long-lived nuclides such as 14 C, 59 Ni, 63 Ni, 99 Tc, 129 I and the transuranium elements. As most of these nuclides are difficult to measure, the correlation between these critical nuclides and some other easily measurable key nuclides such as 60 Co and 137 Cs has been investigated for typical waste streams of Paks Nuclear Power Plant (Hungary) and scaling factors have been proposed. An automated gamma-scanning monitor has been purchased and calibrated to determine the gamma-emitting radionuclides. Radiochemical methods have been developed to determine significant difficult-to-measure radionuclides. The radionuclides of interest have been 3 H, 14 C, 90 Sr, 55 Fe, 59 Ni, 99 Tc, 129 I and TRUs. The measurements taken so far have revealed brand new information and data on radiological composition of waste of WWER-type reactors. The reliability of the radioanalytical methods was checked by an international intercomparison test. For all radionuclides the Hungarian results were in the average range of the total data set. (author)

  7. Foodstuffs, radionuclides, monitoring

    International Nuclear Information System (INIS)

    Denisikov, A.I.

    2000-01-01

    Radionuclide contamination of water and food stuffs as a result of the Chernobyl accident and permissible contents of 90 Sr and 137 Cs are considered in brief. A method of radiation monitoring of food stuffs and water for the radionuclides mentioned is suggested. The method permits employment of the simplest and cheapest radiometric equipment for analysis, whole the high degree of radionuclide concentration using fiber sorbents permits using the instrumentation without expensive shields against external radiation. A description of ion-exchange unit for radiation monitoring of liquid samples of food stuffs or water, is provided [ru

  8. Generator for radionuclide

    International Nuclear Information System (INIS)

    Weisner, P.S.; Forrest, T.R.F.

    1985-01-01

    This invention provides a radionuclide generator of the kind in which a parent radionuclide, adsorbed on a column of particulate material, generates a daughter radionuclide which is periodically removed from the column. This invention is particularly concerned with technetium generators using single collection vials. The generator comprises a column, a first reservoir for the eluent, a second reservoir to contain the volume of eluent required for a single elution, and means connecting the first reservoir to the second reservoir and the second reservoir to the column. Such a generator is particularly suitable for operation by vacuum elution

  9. Probabilistic calculations and sensitivity analysis of parameters for a reference biosphere model assessing the potential exposure of a population to radionuclides from a deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, Christian; Kaiser, Jan Christian [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Munich (Germany); Proehl, Gerhard [International Atomic Energy Agency, Division of Radiation, Transport and Waste Safety, Wagramerstrasse 5, 1400 Vienna (Austria)

    2014-07-01

    Radioecological models are used to assess the exposure of hypothetical populations to radionuclides. Potential radionuclide sources are deep geological repositories for high level radioactive waste. Assessment time frames are long since releases from those repositories are only expected in the far future, and radionuclide migration to the geosphere biosphere interface will take additional time. Due to the long time frames, climate conditions at the repository site will change, leading to changing exposure pathways and model parameters. To identify climate dependent changes in exposure in the far field of a deep geological repository a range of reference biosphere models representing climate analogues for potential future climate states at a German site were developed. In this approach, model scenarios are developed for different contemporary climate states. It is assumed that the exposure pathways and parameters of the contemporary biosphere in the far field of the repository will change to be similar to those at the analogue sites. Since current climate models cannot predict climate developments over the assessment time frame of 1 million years, analogues for a range of realistically possible future climate conditions were selected. These climate states range from steppe to permafrost climate. As model endpoint Biosphere Dose conversion factors (BDCF) are calculated. The radionuclide specific BDCF describe the exposure of a population to radionuclides entering the biosphere in near surface ground water. The BDCF are subject to uncertainties in the exposure pathways and model parameters. In the presented work, probabilistic and sensitivity analysis was used to assess the influence of model parameter uncertainties on the BDCF and the relevance of individual parameters for the model result. This was done for the long half-live radionuclides Cs-135, I-129 and U-238. In addition to this, BDCF distributions for nine climate reference regions and several scenarios were

  10. 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

  11. PABLM: a computer program to calculate accumulated radiation doses from radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1980-03-01

    A computer program, PABLM, was written to facilitate the calculation of internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. This report contains details of mathematical models used and calculational procedures required to run the computer program. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides in the environment after the releases have ended. Radioactive decay is considered during the release of radionuclides, after they are deposited on the plants or ground, and during holdup of food after harvest. The radiation dose models consider several exposure pathways. Doses may be calculated for either a maximum-exposed individual or for a population group. The doses calculated are accumulated doses from continuous chronic exposure. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and MPC's of each radionuclide. The radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption that the contaminated medium is large enough to be considered an infinite volume or plane relative to the range of the emitted radiations. The equations for calculations of the radiation dose from external exposure to shoreline sediments include a correction for the finite width of the contaminated beach.

  12. PABLM: a computer program to calculate accumulated radiation doses from radionuclides in the environment

    International Nuclear Information System (INIS)

    Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1980-03-01

    A computer program, PABLM, was written to facilitate the calculation of internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. This report contains details of mathematical models used and calculational procedures required to run the computer program. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides in the environment after the releases have ended. Radioactive decay is considered during the release of radionuclides, after they are deposited on the plants or ground, and during holdup of food after harvest. The radiation dose models consider several exposure pathways. Doses may be calculated for either a maximum-exposed individual or for a population group. The doses calculated are accumulated doses from continuous chronic exposure. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and MPC's of each radionuclide. The radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption that the contaminated medium is large enough to be considered an infinite volume or plane relative to the range of the emitted radiations. The equations for calculations of the radiation dose from external exposure to shoreline sediments include a correction for the finite width of the contaminated beach

  13. Boundary conditions for pathways, safety analysis and basic criteria for low-level radiation waste site selection

    International Nuclear Information System (INIS)

    Saverot, P.

    1994-01-01

    There are three successive periods in the life of a disposal facility: the operating period, the institutional control period and the unrestricted site access period. The purpose of safety analysis of the disposal facility is to ensure that the radiological impacts for each period in the life of the facility are acceptable under all circumstances. Founded on a deterministic approach, this analysis leads to a determination of the maximum quantity of each radionuclide present in the facility at the beginning of the institutional control period in order for the impacts to be considered acceptable. Safety analysis involves the calculation of the radiological impacts of a given radiological inventory under a selected scenario, from all plausible scenarios of radionuclide migration to the environment in both normal and accident conditions, and taking into account other specified variables. The calculation itself involves an assessment of the quantities of radionuclides that could be released to the environment under the specific scenario selected and following identified pathways, and a determination of the resultant exposure, both internal and external, to the public. An iterative approach is used in the performance of pathways analyses. If the pathways analyses result in unacceptable radiological impacts, either the radiological inventory of the site is reduced or barrier characteristics not previously factored into the analysis are taken into account. New pathways analyses are then performed until the results are within the acceptable range. Once accepted by the safety authorities, the radiological inventory becomes the radiological capacity, which is the approved quantities of specific radionuclides that may be disposed of at the site. The following elaborates on the boundary conditions used in safety analyses and describes the types of pathways analyses performed for a LLW disposal facility

  14. Pathways to man

    International Nuclear Information System (INIS)

    Harley, J.H.

    1980-01-01

    The study of radionuclide pathways leading to man generally has the goal of allowing us to predict human exposure from measurements of the radionuclide concentration in some segment of the environment. This modelling process provides a valuable tool in both the regulatory and health protection fields. However, most of the models in the regulatory field and in the health physics profession were designed to maximize exposure estimates. It is preferable to have scientifically defensible estimates and to add suitable safety factors at the end. Thus we are still faced with the development and validation of suitable models for many of the radionuclides of interest. The most useful models will include means of assessing variability and uncertainty. In this case variability might be considered as the differences in behavior due to age, sex or other factors in animals or man and those differences among plant species or animal species that determine their uptake factors. The uncertainty, on the other hand, would be the estimate of possible error in the experimental measurements. Model parameters would always have some variability even for site-specific cases and broad averages for population groups would have to include a factor expressing the possible variabilty and uncertainity. Thus any exposure calculation would have to be expressed with some range and valid assessments of this range are required

  15. Miscellaneous applications of radionuclide imaging

    International Nuclear Information System (INIS)

    Mishkin, F.S.; Freeman, L.M.

    1984-01-01

    The procedures discussed in this chapter are either developmental, in limited clinical use, or frankly moribund. A number of radionuclide imaging techniques have proved disappointing when approached from a purely anatomic point of view. This is particularly evident to our colleagues with the explosive growth of the noninvasive imaging procedures, magnetic resonance imaging (NMR), CT, and ultrasound, and the introduction of the less invasive digital radiographic approach to vascular opacification, all of which are capable of providing exquisite anatomic or tissue detail beyond the reach of current or reasonably priced nuclear medicine imaging systems. Yet, most nuclear medicine procedures possess the unique advantage of portraying a physiologic function without interfering with that function. Moreover, the procedures can be employed under conditions of stress, which are likely to bring out pathophysiologic abnormalities that remain masked when unchallenged. Information concerning form without functional data has less meaning than both together. The physiologic information inherent in nuclear medicine imaging may often provide not only key diagnostic information but also illuminate a therapeutic trail. Yet, it is often slighted in favor of the anatomic quest. While mastery of the nuances of imaging details remains critical, radionuclide image interpretation must rest upon a firm physiologic foundation. For this reason, this chapter emphasizes the physiologic approach

  16. Radionuclide transfer from mother to embryo

    International Nuclear Information System (INIS)

    Toader, M.; Vasilache, R.A.; Scridon, R.; Toader, M.L.

    1998-01-01

    The transfer of radionuclides from mother to embryo is still a matter of high interest. Therefore, the relation was investigated between the amount of radionuclides in the embryo and the dietary intake of the mother, this for two scenarios: a recurrent intake of variable amounts of radionuclides, and a long-term intake of a relatively constant amount of radionuclides, the radionuclide being 137 Cs. In the first case, the amount of radionuclides present in the embryo increases with the age of the embryo and with the intake of the mother. In the second case, no correlation could be found between the age of the embryo and its radioactive content; only the correlation between the intake of the mother and the radionuclide content of the embryo remained. (A.K.)

  17. Radionuclide diagnosis of emergency states

    International Nuclear Information System (INIS)

    Ishmukhametov, A.I.

    1985-01-01

    Solution of emergency state radionuclide diagnostics from the technical point of view is provided by the application of the mobile quick-operating equipment in combination with computers, by the use of radionuclides with acceptable for emergency medicine characteristics and by development of radionuclide investigation data propcessing express-method. Medical developments include the study of acute disease and injury radioisotope semiotics, different indication diagnostic value determining, comparison of the results, obtained during radionuclide investigation, with clinicolaboratory and instrumental data, separation of methodical complex series

  18. Sorption/ desorption studies of some radionuclides between disposal soil fractions and ground water. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    El-Reefy, S A; Ali, A [Hot Lab. Centre, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The radioactive waste management program in egypt includes shallow land disposal area for waste package disposal. The proposed site is located to the east of the Hot laboratory centre at Inchas. Assessment of the efficiency of the different sediments and rocks found in this area as a barrier against release of radioactive nuclide to the environment is of major importance. This study is related to evaluate the migration of Cs, Co, and Am within the environment of this site. In this concern, seven soil fractions were taken from a digging well from the proposed disposal site at different depths down to the basalt sheets. A column was constructed containing the soil fractions representing the stratigraphic successions taken from the site. The radionuclides; Cs-137, Co-60, and Am-241 were in this investigation representatives for mono, di- and tri-valent elements and also represented the radionuclides which are mostly associated with radioactive wastes. The sorption/ desorption studies of these radionuclides with the different soil fractions and ground water from the proposed disposal site were carried out. The results obtained were used to predict the migration pathways of these radionuclides within the disposal environment. 2 figs., 1 tab.

  19. Sorption/ desorption studies of some radionuclides between disposal soil fractions and ground water. Vol. 3

    International Nuclear Information System (INIS)

    El-Reefy, S.A.; Ali, A.

    1996-01-01

    The radioactive waste management program in egypt includes shallow land disposal area for waste package disposal. The proposed site is located to the east of the Hot laboratory centre at Inchas. Assessment of the efficiency of the different sediments and rocks found in this area as a barrier against release of radioactive nuclide to the environment is of major importance. This study is related to evaluate the migration of Cs, Co, and Am within the environment of this site. In this concern, seven soil fractions were taken from a digging well from the proposed disposal site at different depths down to the basalt sheets. A column was constructed containing the soil fractions representing the stratigraphic successions taken from the site. The radionuclides; Cs-137, Co-60, and Am-241 were in this investigation representatives for mono, di- and tri-valent elements and also represented the radionuclides which are mostly associated with radioactive wastes. The sorption/ desorption studies of these radionuclides with the different soil fractions and ground water from the proposed disposal site were carried out. The results obtained were used to predict the migration pathways of these radionuclides within the disposal environment. 2 figs., 1 tab

  20. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions, Calendar Year 2010

    International Nuclear Information System (INIS)

    2011-01-01

    limit by using environmental measurements of radionuclide air concentrations at critical receptor locations (U.S. Environmental Protection Agency (EPA) and DOE, 1995). This method was approved by the EPA for use on the NNSS in 2001(EPA, 2001a) and has been the sole method used since 2005. Six locations on the NNSS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo-critical receptor stations, because no member of the public actually resides at these onsite locations. Compliance is demonstrated if the measured annual average concentration is less than the NESHAP Concentration Levels (CLs) for Environmental Compliance listed in 40 CFR 61, Appendix E, Table 2 (CFR, 2010a). For multiple radionuclides, compliance is demonstrated when the sum of the fractions (determined by dividing each radionuclide's concentration by its CL and then adding the fractions together) is less than 1.0. In 2010, the potential dose from radiological emissions to air, resulting from both current and past NNSS activities, at onsite compliance monitoring stations was well below the 10 mrem/yr dose limit. Air sampling data collected at all air monitoring stations had average concentrations of radioactivity that were a fraction of the CL values. Concentrations ranged from less than 1 percent to a maximum of 17 percent of the allowed NESHAP limit. Because the nearest member of the public resides about 20 kilometers from potential release points on the NNSS, dose to the public would be only a small fraction of that measured on the NNSS. The potential dose to the public from NLVF emissions was also very low at 0.000032 mrem/yr, more than 300,000 times lower than the 10 mrem/yr limit.

  1. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions, Calendar Year 2011

    International Nuclear Information System (INIS)

    2012-01-01

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan. Radionuclides from the Fukushima nuclear power plant were detected at the NNSS in March 2011 and are discussed further in Section III. The NNSS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the EPA for use on the

  2. Radionuclide evaluation of left ventricular function with nonimaging probes.

    Science.gov (United States)

    Wexler, J P; Blaufox, M D

    1979-10-01

    Portable nonimaging probes have been developed that can evaluate left ventricular function using radionuclide techniques. Two modes of data acquisition are possible with these probe systems, first-pass and gated. Precordial radiocardiograms obtained after a bolus injection can be used to determine cardiac output, pulmonary transit time, pulmonary blood volume, left ventricle ejection fraction, and left-to-right shunts. Gated techniques can be used to determine left ventricular ejection fraction and sytolic time intervals. Probe-determined indices of left ventricular function agree excellently with comparable measurements determined by conventional camera-computer methods as well as by invasive techniques. These have begun to be used in a preliminary manner in a variety of clinical problems associated with left ventricular dysfunction. This review discusses the types of probe systems available, the methods used in positioning them, and details the specifics of their data acquisition and processing capacity. The major criticisms of probe methods are that they are nonimaging and that they measure global rather than regional left ventricular function. In spite of these criticisms, probe systems, because of their portability, high sensitivity, and relatively low cost are useful supplements to conventional camera-computer systems for the measurement of parameters of left ventricular performance using radionuclide techniques.

  3. 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.

  4. Radionuclide daughter inventory generator code: DIG

    International Nuclear Information System (INIS)

    Fields, D.E.; Sharp, R.D.

    1985-09-01

    The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs

  5. Field investigations of the uptake of radionuclides by a dairy herd

    International Nuclear Information System (INIS)

    Dodd, N.J.

    1983-01-01

    A brief outline is given of a current study of the transfer of radionuclides in the pasture-cow-milk pathway at a farm situated close to the Sellafield nuclear installation. Samples collected include airborne dust, rainwater, herbage, supplementary feed, milk and tissue, bone and organs from slaughtered cows. Data collected so far have been used to derive coefficients that quantify the transfer of 90 Sr, 137 Cs, 239 Pu and 241 Am to meat and milk. (U.K.)

  6. A compilation of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways and the suggested default values for the RESRAD code

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.Y.; Biwer, B.M.; Yu, C.

    1993-08-01

    The ongoing development and revision of the RESRAD computer code at Argonne National Laboratory requires update of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways. Default values for these transfer factors used in published radiological assessment reports are compiled and compared with values used in RESRAD. The differences among the reported default values used in different radiological assessment codes and reports are also discussed. In data comparisons, values used in more recent reports are given more weight because more recent experimental work tends to be conducted under better-defined laboratory or field conditions. A new default value is suggested for RESRAD if one of the following conditions is met: (1) values used in recent reports are an order of magnitude higher or lower than the default value currently used in RESRAD, or (2) the same default value is used in several recent radiological assessment reports.

  7. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    Energy Technology Data Exchange (ETDEWEB)

    P. Goodell; J. Walton; P.J. Rodriguez

    2005-07-11

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration.

  8. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    International Nuclear Information System (INIS)

    Goodell, P.; Walton, J.; Rodriguez, P.J.

    2005-01-01

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration

  9. Transport of Gas Phase Radionuclides in a Fractured, Low-Permeability Reservoir

    Science.gov (United States)

    Cooper, C. A.; Chapman, J.

    2001-12-01

    The U.S. Atomic Energy Commission (predecessor to the Department of Energy, DOE) oversaw a joint program between industry and government in the 1960s and 1970s to develop technology to enhance production from low-permeability gas reservoirs using nuclear stimulation rather than conventional means (e.g., hydraulic and/or acid fracturing). Project Rio Blanco, located in the Piceance Basin, Colorado, was the third experiment under the program. Three 30-kiloton nuclear explosives were placed in a 2134 m deep well at 1780, 1899, and 2039 m below the land surface and detonated in May 1973. Although the reservoir was extensively fractured, complications such as radionuclide contamination of the gas prevented production and subsequent development of the technology. Two-dimensional numerical simulations were conducted to identify the main transport processes that have occurred and are currently occurring in relation to the detonations, and to estimate the extent of contamination in the reservoir. Minor modifications were made to TOUGH2, the multiphase, multicomponent reservoir simulator developed at Lawrence Berkeley National Laboratories. The simulator allows the explicit incorporation of fractures, as well as heat transport, phase change, and first order radionuclide decay. For a fractured two-phase (liquid and gas) reservoir, the largest velocities are of gases through the fractures. In the gas phase, tritium and one isotope of krypton are the principle radionuclides of concern. However, in addition to existing as a fast pathway, fractures also permit matrix diffusion as a retardation mechanism. Another retardation mechanism is radionuclide decay. Simulations show that incorporation of fractures can significantly alter transport rates, and that radionuclides in the gas phase can preferentially migrate upward due to the downward gravity drainage of liquid water in the pores. This project was funded by the National Nuclear Security Administration, Nevada Operations Office

  10. Radionuclide release from low-level waste in field lysimeters

    International Nuclear Information System (INIS)

    Oblath, S.B.

    1986-01-01

    A field program has been in operation for 8 years at the Savannah River Plant (SRP) to determine the leaching/migration behavior of low-level radioactive waste using lysimeters. The lysimeters are soil-filled caissons containing well characterized wastes, with each lysimeter serving as a model of a shallow land burial trench. Sampling and analysis of percolate water and vegetation from the lysimeters provide a determination of the release rates of the radionuclides from the waste/soil system. Vegetative uptake appears to be a major pathway for migration. Fractional release rates from the waste/soil system are less than 0.01% per year. Waste-to-soil leach rates up to 10% per year have been determined by coring several of the lysimeters. The leaching of solidified wasteforms under unsaturated field conditions has agreed well with static, immersion leaching of the same type waste in the laboratory. However, releases from the waste/soil system in the lysimeter may be greater than predicted based on leaching alone, due to complexation of the radionuclides by other components leached from the wastes to form mobile, anionic species

  11. Biological implications of radionuclides released from nuclear industries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-08-15

    The development of nuclear power technologies has led to a rapid increase in the number of reactors and other installations including fuel reprocessing and radioactive waste treatment plants in operation. Associated with these developments are the concomitant possibilities for release of radionuclides in the environment, which in turn might exert some biological impacts including late somatic and genetic effects on man. The principal objective of the Agency's symposium was, therefore, to review critically the current information on the biological effects of exposure to low levels of incorporated radionuclides and the radiation doses absorbed from them. The purpose of this review was to provide a sound scientific basis on which to evaluate radiation safety standards, risk-benefit analysis, as well as the regulatory control and management of nuclear wastes. The major part of the discussions centered around the problems of the radiobiology, radio-oncology, radio-ecology and toxicology of the transuranic such as such as plutonium, americium, curium as well as radionuclide species like tritium, krypton and iodine among others, which are expected to be released from these nuclear installations. Current data and practical information obtained through suitably designed animal studies and also from epidemiological, ecological and food-chain analyses and other relevant follow-up surveys of late effects in accidentally exposed occupational personnel were reported for discussion and risk evaluation.

  12. Information on biological health effects of ionizing radiation and radionuclides: the rule of a web site

    International Nuclear Information System (INIS)

    Comte, A.; Gaillard-Lecanu, E.; Flury-Herard, A.; Ourly, F.; Hemidy, P.; Lallemand, J.

    2006-01-01

    The purpose of this project is to provide a source of information on biological and health effects of radionuclides and ionizing radiation in an easy to use format. Reported work is made up of two distinct parts: data sheets for selected radionuclides and a web file. Data sheets: Specific radiation data sheets provide an overview of the properties, the environmental behaviour, the different pathways of human exposure and the biological and health consequences of selected radionuclides. Radionuclides that have been selected are those commonly dealt with in nuclear industry (and in other areas such as medicine) and released to the environment or naturally occurring (plutonium, tritium, carbon 14). Data sheets corresponding to the different radionuclides are based on the main sources of scientific information in dosimetry, epidemiology, radiobiology and radiation protection. These data sheets are intended for radiation protection specialists and physicians. They include: main physical and chemical characteristics, main radiation protection data: dose coefficients (public, workers), dose limits sources, total released estimate (nuclear industry, atmospheric tests, main pathway of human exposure and biological behaviour, biological and health effects, medical supervision, treatment a list of the main references, appendix providing accurate information. Web file: http://www-dsv.cea.fr/doc/carmin_ext/fond.php This web file provides a source of information on biological and health effects of ionizing radiation and biological basic knowledge of radiation protection. Available for consultation via Internet, compiled information provides, in a same file, subjects as varied as biological mechanisms, ionizing radiations action, biological and health effects, risk assessment This file is mainly intended to assist in informing and training of non-specialist readership (students, teaching on radiation protection basic knowledge. This electronic document is divided in three

  13. 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.

  14. General review of literature relevant to coastal water discharges

    International Nuclear Information System (INIS)

    Pentreath, R.J.

    1985-01-01

    This review on the behaviour of radionuclides released into coastal water from the radioactive discharges, prepared on the basis of existing publications and documents, is divided into parts on pathways of exposure, behaviour of radionuclides in coastal environments, biological avialability of radionuclides, habit surveys and critical groups, assessment of dose to man and the effects of radiation on aquatic organisms

  15. Evaluation of the absorbed doses in conditions of external and internal contamination with radionuclides

    International Nuclear Information System (INIS)

    Milivojevic, K.; Stojanovic, D.; Markovic, P.

    1981-01-01

    In experimental conditions of contamination with radionuclides of the skin and skin injuries, an evaluation of the degree of local irradiation in decontamined region and doses absorbed in organs of selective accumulating was carried out by use of mathematical models and tissue-equivalent thermoluminescent dosemeters. The evaluation of the absorbed doses based on conception, that in adequate analyses of decontamination effect, as a most efficient medico-prophilactic measure from local and total irradiation, should be taken into account the total body burden of the penetrated radionuclide, selective accumulating in critical organs or tissues, as well as the residual radioactivity in decontaminated region. (author)

  16. Residual neutron-induced radionuclides in a soil sample collected in the vicinity of the criticality accident site in Tokai-mura, Japan: A Progress Report

    International Nuclear Information System (INIS)

    Nakanishi, Takashi; Hosotani, Risa; Komura, Kazuhisa; Muroyama, Toshiharu; Kofuji, Hisaki; Murata, Yoshimasa; Kimura, Shinzo; Kumar Sahoo, Sarata; Yonehara, Hidenori; Watanabe, Yoshito; Ban-nai, Tada-aki

    2000-01-01

    Residual neutron-induced radionuclides were measured in a soil sample collected in the vicinity of the location where a criticality accident occurred (in Tokai-mura, from 30 September to 1 October, 1999). Concentrations of 24 Na, 140 La, 122 Sb, 59 Fe, 124 Sb, 46 Sc, 65 Zn, 134 Cs and 60 Co in the soil sample were determined by γ-ray spectrometry, and neutron activation analysis was carried out for selected target elements in the sample. Tentative estimates of the apparent thermal and epithermal neutron fluences which reached the sample were obtained through combined analyses of 59 Fe/ 58 Fe, 124 Sb/ 123 Sb, 46 Sc/ 45 Sc, 65 Zn/ 64 Zn, 134 Cs/ 133 Cs and 60 Co/ 59 Co

  17. Extrapolation of experimental data on late effects of low-dose radionuclides in man

    International Nuclear Information System (INIS)

    Kalistratova, V.S.; Nisimov, P.G.

    1997-01-01

    The situation of living of population on radionuclide contamination areas was simulated in the experimental study using white strainless rats of different ages. The significance of age for late stochastic effects of internal radionuclide contamination with low doses of 131 I, 137 Cs, 144 Ce and 106 Ru was studied. Some common regularities and differences in late effects formation depending on age were found. Results of the study showed that the number of tumors developed increased in groups of animals exposed at the youngest age. The younger animal at the moment of internal radionuclide contamination, the higher percentage of malignant tumors appeared. It was especially so for tumors of endocrine glands (pituitary, suprarenal,- and thyroid). Differences in late effects formation related to different type of radionuclide distribution within the body were estimated. On the base of extrapolation the conclusion was made that human organism being exposed at early postnatal or pubertal period could be the most radiosensitive (1.5-2.0 or sometimes even 3-5 times higher than adults). Data confirmed the opinion that children are the most critical part of population even in case of low dose radiation exposure. (author)

  18. Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through hydrological processes

    Science.gov (United States)

    Onda, Yuichi; Kato, Hiroaki; Patin, Jeremy; Yoshimura, Kazuya; Tsujimura, Maki; Wakahara, Taeko; Fukushima, Takehiko

    2013-04-01

    Previous experiences such as Chernobyl Nuclear Power Plant accident have confirmed that fallout radionuclides on the ground surface migrate through natural environment including soils and rivers. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers should be monitored. However, such comprehensive studies on migration through forests, soils, ground water and rivers have not been conducted so far. Here, we present the following comprehensive investigation was conducted to confirm migration of radionuclides through natural environment including soils and rivers. 1)Study on 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 5)Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use 6)Study on paddy-to-river transfer of radionuclides through suspended sediments 7)Study on river-to-ocean transfer of radionuclides via suspended sediments 8)Confirmation of radionuclide deposition in ponds and reservoirs

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  20. Critical groups - basic concepts

    International Nuclear Information System (INIS)

    Carter, M.W.

    1992-01-01

    The potential exposure pathways from the land application site to man are presented. It is emphasised that the critical group is not necessary the population group closest to the source. It could be the group impact by the most significant pathways(s). Only by assessing the importance of each of these pathways and then combining them can a proper choice of critical group be made. It would be wrong to select a critical group on the basis that it seems the most probable one, before the pathways have been properly assessed. A calculation in Carter (1983) suggested that for the operating mine site, the annual doses to an Aboriginal person, a service worker and a local housewife, were all about the same and were in the range 0.1 to 0.2 mSv per year. Thus it may be that for the land application area, the critical group turns out to be non-Aboriginal rather than the expected Aboriginal group. 6 refs., 3 figs

  1. Imprecision of dose predictions for radionuclides released to the environment: an application of a Monte Carlo simulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, G; Hoffman, F O

    1980-01-01

    An evaluation of the imprecision in dose predictions for radionuclides has been performed using correct dose assessment models and knowledge of model parameter value uncertainties. The propagation of parameter uncertainties is demonstrated using a Monte Carlo technique for elemental iodine 131 transported via the pasture-cow-milk-child pathway. Results indicated that when site-specific information is unavailable, the imprecision inherent in the predictions for this pathway is potentially large. (3 graphs, 25 references, 5 tables)

  2. Conditions and processes affecting radionuclide transport

    Science.gov (United States)

    Simmons, Ardyth M.; Neymark, Leonid A.

    2012-01-01

    Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths beneath Yucca Mountain are controlled by dissolution reactions, silica and calcite precipitation, and ion-exchange reactions. Radionuclide concentrations along flow paths from a repository could be limited by (1) low waste-form dissolution rates, (2) low radionuclide solubility, and (3) radionuclide sorption onto geological media.

  3. Field investigations of the uptake of radionuclides by a dairy herd

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, N J [National Radiological Protection Board, Harwell (UK)

    1983-11-01

    A brief outline is given of a current study of the transfer of radionuclides in the pasture-cow-milk pathway at a farm situated close to the Sellafield nuclear installation. Samples collected include airborne dust, rainwater, herbage, supplementary feed, milk and tissue, bone and organs from slaughtered cows. Data collected so far have been used to derive coefficients that quantify the transfer of /sup 90/Sr, /sup 137/Cs, /sup 239/Pu and /sup 241/Am to meat and milk.

  4. MARFA version 3.2.2 user's manual: migration analysis of radionuclides in the far field

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott; Mancillas, James (Center for Nuclear Waste Regulatory Analyses, Southwest Research Inst., San Antonio, TX (United States))

    2009-12-15

    The computer code Migration Analysis of Radionuclides in the Far Field (MARFA) uses a particle-based Monte Carlo method to simulate the transport of radionuclides in a sparsely fractured geological medium. Transport in sparsely fractured rock is of interest because this medium may serve as a barrier to migration of radionuclides to the accessible environment. The physical processes represented in MARFA include advection, longitudinal dispersion, Fickian diffusion into an infinite or finite rock matrix, equilibrium sorption, decay, and in-growth. Multiple non-branching decay chains of arbitrary length are supported. This document describes the technical basis and input requirements for MARFA Version 3.2.2. MARFA Version 3.2 included new capabilities to accommodate transient flow velocities and sorption parameters, which are assumed to be piecewise constant in time. Version 3.2.1 was a minor change from Version 3.2 to allow a more convenient input format for sorption information. New capabilities in Version 3.2.2 include an option to specify a non-zero start time for the simulation, an optional input parameter that decreases the amount of retention within a single fracture because of flow channeling, and an alternative method for sampling the radionuclide source. MARFA uses the particle on random streamline segment algorithm/Painter et al. 2006/, a Monte Carlo algorithm combining time-domain random walk methods with pathway stochastic simulation. The algorithm uses non-interacting particles to represent packets of radionuclide mass. These particles are moved through the system according to rules that mimic the underlying physical transport and retention processes. The set of times required for particles to pass through the geological barrier are then used to reconstruct discharge rates (mass or activity basis). Because the algorithm uses non-interacting particles, the transport and retention processes are limited to those that depend linearly on radionuclide

  5. Relative importance of food and water pathways in the bio-accumulation of zinc

    International Nuclear Information System (INIS)

    Renfro, W.C.; Fowler, S.W.; Heyraud, M.; LaRosa, J.

    1974-01-01

    The relative importance of the food versus water pathway as a source of radionuclides to aquatic organisms is studied through laboratory experiments allowing groups of animals to accumulate 65 Zn from the two pathways simultaneously in the same simulated ecosystem. Mean whole body concentration factors of 65 Zn and stable zinc in shrimp, crab, fish and mussels are recorded. In shrimp and fish accumulation of 65 Zn through the food pathway is reported more than the water pathway though fluctuations in food quality and feeding rates could alter zinc absorption kinetics

  6. Evaluation of data on the transfer of radionuclides in the food chain post-Chernobyl action

    International Nuclear Information System (INIS)

    Desmet, G.; Sinnaeve, J.

    1992-01-01

    During the accident at Chernobyl large amounts of radioactive materials were released into the atmosphere and distributed all over Europe. Depending on the trajectories of the radioactive clouds and the large variation of rainfall during its passage through, large local and regional differences in deposition were observed, leading to an enhanced contamination of soil and plants. Consequently, the radionuclides entered the foodchain by several pathways. The radiological consequences of radionuclides discharged from nuclear installations usually are evaluated using doses assessment models. In these models the passage from one compartment into another, e.g. the transfer from soil into plants, from plants into milk or meat is defined by transfer factors, which are influenced by various parameters. From the long term point of view only the long-lived nuclides like 134/137 Cs are important for long term radiation risk assessment after the Chernobyl accident. In this accident the release of radioactive materials took place over a longer time period and varied in rate and radionuclide composition. Some regions of Europe were contaminated several times. To improve radiation dose prediction the CEC has initiated the Post-Chernobyl radiation protection programme 'Evaluation of Data on the Transfer of Radionuclides in the Foodchain' including five main items to be studied by different laboratories: 1. Impact of chemical speciation on the radionuclide transfer in terrestrial ecosystems after a core disruptive accident, especially in soils and plants. 2. Transfer paths of radionuclides in seminatural and natural ecosystems and their role in contaminating the foodchain. 3. Validation of soil-to-plant parameters. 4. Transfer of radionuclides to animals and animal products. 5. Transfer paths in aquatic systems and their importance for the contamination of the foodchain

  7. Ventral aspect of the visual form pathway is not critical for the perception of biological motion

    Science.gov (United States)

    Gilaie-Dotan, Sharon; Saygin, Ayse Pinar; Lorenzi, Lauren J.; Rees, Geraint; Behrmann, Marlene

    2015-01-01

    Identifying the movements of those around us is fundamental for many daily activities, such as recognizing actions, detecting predators, and interacting with others socially. A key question concerns the neurobiological substrates underlying biological motion perception. Although the ventral “form” visual cortex is standardly activated by biologically moving stimuli, whether these activations are functionally critical for biological motion perception or are epiphenomenal remains unknown. To address this question, we examined whether focal damage to regions of the ventral visual cortex, resulting in significant deficits in form perception, adversely affects biological motion perception. Six patients with damage to the ventral cortex were tested with sensitive point-light display paradigms. All patients were able to recognize unmasked point-light displays and their perceptual thresholds were not significantly different from those of three different control groups, one of which comprised brain-damaged patients with spared ventral cortex (n > 50). Importantly, these six patients performed significantly better than patients with damage to regions critical for biological motion perception. To assess the necessary contribution of different regions in the ventral pathway to biological motion perception, we complement the behavioral findings with a fine-grained comparison between the lesion location and extent, and the cortical regions standardly implicated in biological motion processing. This analysis revealed that the ventral aspects of the form pathway (e.g., fusiform regions, ventral extrastriate body area) are not critical for biological motion perception. We hypothesize that the role of these ventral regions is to provide enhanced multiview/posture representations of the moving person rather than to represent biological motion perception per se. PMID:25583504

  8. Environmental impact of nuclear industry. Results of research on environmental radionuclide transfer

    International Nuclear Information System (INIS)

    Bovard, P.; Grauby, A.

    1977-01-01

    Among the various activities of nuclear industry, uranium mining and milling raise a particular problem as they release radium, a radionuclide with high radiotoxicity. Besides, radioactive releases into the environment are accompanied by a significant chemical load. A 3 year study was therefore carried out in order to assess the environmental impact of both types of plants. The data obtained showed: a high level of radium 226 in waters, even after full dilution of the effluents in the available flow of the receiving watercourse, in excess of the MPC population. The effects of the released chemical load (metals) on environmental behavior of radium, viz: radium reconcentration on bottoms with possibility of going into solution again, under certain conditions (swelling of rivers) or possible contamination of underground water; a particular mode of contamination of aquatic species (fish especially) liable to result in high levels in this food chain. Besides operational monitoring, a radioecological inventory should be carried out at the levels of water, sediments, aquatic flora and fauna, soils and agricultural produces in order to identify the pathways to man, to set up monitoring as a function of the critical pathways to man, to propose a release program (dilution and treatment) likely to reduce hazards as low as possible. The instance of radium contamination processes in an aquatic ecosystem demonstrates that before operation, a radioecological study of the future mining site should be carried out in order to avoid high concentrations at the various biological food chain levels [fr

  9. Caesium Radionuclide Uptake from Wet Soil to Kangkung Plant (Ipomoea sp)

    International Nuclear Information System (INIS)

    Putu Sukmabuana; Poppy Intan Tjahaja

    2009-01-01

    Caesium radionuclide transfer from soil to kangkung plant (Ipomoea sp) generally consumed by people had been examined to obtain transfer factor value for internal radiation dose assessment via soil-plant-human pathway. The kangkung plants were cultivated on watered soil medium containing 134 Cs with concentration of about 80 Bq/g, and the 134 Cs uptake by plants, i.e root, stem, and leaves, were measured using gamma spectrometer. The 134 Cs plant uptake was expressed as transfer factor, i.e. ratio of plant 134 Cs concentration to 134 Cs concentration on soil medium. From this research it was obtained transfer factor value of 134 C from soil to plant is 0.07, and the transfer factor for root, stem, and leaves are 0.34 ; 0.05 ; 0,03 respectively, after 45 days cultivation. The transfer factor values are less than one, indicate that kangkung plant do not accumulate Cs radionuclide from soil. (author)

  10. Guidance on offsite emergency radiation measurement systems. Phase 2: The milk pathway

    International Nuclear Information System (INIS)

    1984-04-01

    This document provides guidance to State and local governments and to Federal agencies on offsite emergency measurement of radionuclides after an accident involving a light-water nuclear power plant; in particular, this document provides guidance on determining the dose commitment from the milk pathway. Protective action levels proposed by the Food and Drug Administration (FDA) for milk are used as the basis for monitoring requirements. Measurement of radionuclides in milk should be made at the earliest practical point in the production chain: dairy farms, receiving and transfer stations, processing plants or marketing facilities. Early monitoring will provide data to keep significantly contaminated milk out of distribution and will provide the basis for the most timely emergency response action. Radioiodine plus four other radionuclides, cesium-134, cesium-137, strontium-89, and strontium-90, contribute significantly to dose via the milk pathway; of the most severe potential accident, the short-term dose via the milk pathway from radioiodine is significantly greater than that of cesium or strontium. There is no emergency field monitoring instrumentation available for accurately monitoring cesium and strontium, particularly in the presence of radioiodine. Radioiodine can be a potential contamination problem in liquid milk, whereas radiocesium and radiostrontium can be a contamination problem in processed milk products. Monitoring for the long half-life nuclides such as cesium and strontium requires sophisticated equipment or chemistry procedures which are only available in a laboratory. 2 references, 21 figures, 21 tables

  11. 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

  12. Impact assessment of radionuclides released to environment from the European Spallation Source

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S.; Andersson, K. [Technical University of Denmark (Denmark); Ene, D. [European Spallation Soure AB - ESS, Lund (Sweden)

    2014-07-01

    The European Spallation Source (ESS) is a large science and technology infrastructure project currently under construction in Lund, Sweden, with operation planned by 2019. The facility design and construction includes a linear proton accelerator, a heavy-metal target station, neutron instruments, laboratories, and a data management and software development centre. During operation the ESS will produce a wide range of radionuclides via spallation and activation processes. Radiological assessments are needed to ensure that operational discharges and releases from potential incidents/accidents are within acceptable limits. The spectrum of radionuclides produced at ESS is quite different from that produced in nuclear power plants and assessment work has therefore been challenged by lack of information on less well-known radionuclides. Traditional assessment methodologies have been applied focusing on releases to air and public sewer systems and calculating radiation doses to representative persons living in and near Lund close to the ESS site. Exposure pathways considered include external radiation from radionuclides in air, external radiation from radionuclides deposited on ground and skin, inhalation of radionuclides and ingestion of locally produced contaminated food. Atmospheric dispersion has been simulated with the Gaussian plume model which is considered adequate within a few kilometres. Effects of release height have been investigated and site specific values of other parameters such as wind speed, wind direction, rain fall etc. have been used. Contamination of food has been calculated from the (ECOSYS) food dose model used in the RODOS and ARGOS decision support systems. The food dose model does not contain specific data for a number of ESS relevant radionuclides, e.g. {sup 7}Be, {sup 32}P and {sup 35}S. The data required include mobility of these isotopes, soil-to-plant concentration ratios and equilibrium transfer factors of daily intake by ingestion of meat

  13. Phytoremediation of radionuclides: an emerging alternative

    International Nuclear Information System (INIS)

    Singh, Shraddha

    2013-01-01

    Proliferation of nuclear power industry, nuclear weapon testing, dismantling of existing nuclear weapons and occasional accidents have contributed to an enhancement in the level of radionuclides in the environment. The radionuclides due to their long half life and transfer through the food chain effect adversely to normal biological systems. Hence, it is essential to effectively remove the radionuclides from contaminated soils and solutions. Phytoremediation - the use of plants for remediation of toxic metals and radionuclides has been recognized as an aesthetically pleasing, low cost and environment friendly in situ method. Phytoremediation is an umbrella term which covers several plant based approaches. Plants have shown the potential of remediation of these radionuclides from spiked solutions, low level nuclear waste and soil. Various aspects of phytoremediation as well as potential of various plants for remediation of radionuclides will be discussed here. (author)

  14. Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

    Energy Technology Data Exchange (ETDEWEB)

    Napier, Bruce A.; Fellows, Robert J.; Krupka, Kenneth M.

    2007-10-01

    This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by

  15. Environmental pathways of radioactivity to man

    International Nuclear Information System (INIS)

    Johns, T.F.

    1983-01-01

    An attempt has been made to discuss environmental pathways and their significance in a way which will be understood by non-specialists. The role of these pathways in the general structure of radiological protection is explained and the more important pathways to man from releases into the air and the aquatic environment are discussed generally. The various mechanisms which lead to the dispersion or reconstruction of radioactive materials are discussed and their importance stressed. The more important pathways for particular groups of radionuclides from the nuclear power industry are dealt with in detail and information resulting from many theoretical and practical studies of the situations at particular locations summarized. There is detailed discussion about the doses to local population groups and about worldwide doses as a result of the release of certain long-lived radioactive species. The corresponding pathways and resulting doses from natural radiation are detailed to illustrate that the doses from the nuclear power industry are small in comparison, and brief consideration is given to animal and plant doses from the industry. (U.K.)

  16. Radionuclide migration test using undisturbed aerated soil

    International Nuclear Information System (INIS)

    Yamamoto, Tadatoshi; Ohtsuka, Yoshiro; Ogawa, Hiromichi; Wadachi, Yoshiki

    1988-01-01

    As one of the most important part of safety assessment on the shallow land disposal of lowlevel radioactive waste, the radionuclide migration was studied using undisturbed soil samples, in order to evaluate an exact radionuclide migration in an aerated soil layer. Soil samples used in the migration test were coastal sand and loamy soil which form typical surface soil layers in Japan. The aqueous solution containing 60 CoCl 2 , 85 SrCl 2 and 137 CsCl was fed into the soil column and concentration of each radionuclide both in effluent and in soil was measured. Large amount of radionuclides was adsorbed on the surface of soil column and small amount of radionuclides moved deep into the soil column. Difference in the radionuclide profile was observed in the low concentration portion particularly. It is that some fractions of 60 Co and 137 Cs are stable in non-ionic form and move downward through the soil column together with water. The radionuclide distribution in the surface of soil column can be fairly predicted with a conventional migration equation for ionic radionuclides. As a result of radionuclide adsorption, both aerated soil layers of coastal sand and loamy soil have large barrier ability on the radionuclide migration through the ground. (author)

  17. 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)

  18. Integration into JRODOS the models of radionuclide transport in rivers, reservoirs and coastal waters to support the emergency response in early accidental stages

    Energy Technology Data Exchange (ETDEWEB)

    Zheleznyak, M.; Bezhenar, R.; Boyko, O.; Ievdin, I.; Koshebutsky, V.; Maderich, V. [Institute of Mathematical Machines and Systems, National Academy of Sciences of Ukraine (Ukraine); Raskob, W.; Trybushnyi, D. [Karlsruhe Institute of Technology, Institut fuer Kern- und Energietechnik (Germany)

    2014-07-01

    The decision support system for offsite nuclear emergency management RODOS (Real-time on-line decision support), developed under several EC RTD Framework Programs, contains many models related to support decision making in case of a nuclear or radiological emergency. Based on the request of the end users, it was re-engineered based on the JAVA technology and further named JRODOS. The consequences of the Fukushima Daiichi Nuclear Power Plant accident clearly demonstrated the importance of modeling tools predicting the radionuclide transport in marine and freshwater environment and assessing the doses to the public via the aquatic food chain to improve decision making in general. As a consequence, such an activity was launched as part of the European project PREPARE aiming to integrate the 3-dimensional model THREETOX for the radionuclide transport in coastal waters, estuaries, deep lakes, and reservoirs into hydrological model chain of JRODOS - JHDM (JRODOS Hydrological Dispersion Module). So far JHDM contains several aquatic radionuclide transport models describing the sequence of the processes 'atmospheric fallout to watershed' - 'radionuclide inflow to a river net' - 'radionuclide transport in river' - 'doses via aquatic pathways'. The implementation of the THREETOX model into this chain by developing also a user friendly interface will extend the applicability of JRODOS to deep fresh water bodies and marine coastal waters. This paper describes the assessment capabilities of this advanced model chain for two examples of the JRODOS implementation in Ukraine. JRODOS is installed in the emergency centers for two Ukrainian Nuclear Power Plants (NPP) - Zaporizzhya NPP (ZNPP) and Rivne NPP (RNPP). The different models of the JHDM were customized for these NPPs taking into account the characteristics of the water bodies in the surroundings of the NPPs. For the RNPP, located at the bank of the Sozh River which is a tributary of the

  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. 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

  1. Recommended Henry’s Law Constants for Non-Groundwater Pathways Models in GoldSim

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-06-20

    This memorandum documents the source and numerical value of Henry’s law constants for volatile radionuclides of interest used in the non-groundwater (air and radon) pathways models for the 2018 E-Area Performance Assessment.

  2. Illicit Trafficking of Natural Radionuclides

    Science.gov (United States)

    Friedrich, Steinhäusler; Lyudmila, Zaitseva

    2008-08-01

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium (20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces.

  3. Illicit Trafficking of Natural Radionuclides

    International Nuclear Information System (INIS)

    Friedrich, Steinhaeusler; Lyudmila, Zaitseva

    2008-01-01

    Natural radionuclides have been subject to trafficking worldwide, involving natural uranium ore (U 238), processed uranium (yellow cake), low enriched uranium ( 20% U 235), radium (Ra 226), polonium (Po 210), and natural thorium ore (Th 232). An important prerequisite to successful illicit trafficking activities is access to a suitable logistical infrastructure enabling an undercover shipment of radioactive materials and, in case of trafficking natural uranium or thorium ore, capable of transporting large volumes of material. Covert en route diversion of an authorised uranium transport, together with covert diversion of uranium concentrate from an operating or closed uranium mines or mills, are subject of case studies. Such cases, involving Israel, Iran, Pakistan and Libya, have been analyzed in terms of international actors involved and methods deployed. Using international incident data contained in the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) and international experience gained from the fight against drug trafficking, a generic Trafficking Pathway Model (TPM) is developed for trafficking of natural radionuclides. The TPM covers the complete trafficking cycle, ranging from material diversion, covert material transport, material concealment, and all associated operational procedures. The model subdivides the trafficking cycle into five phases: (1) Material diversion by insider(s) or initiation by outsider(s); (2) Covert transport; (3) Material brokerage; (4) Material sale; (5) Material delivery. An Action Plan is recommended, addressing the strengthening of the national infrastructure for material protection and accounting, development of higher standards of good governance, and needs for improving the control system deployed by customs, border guards and security forces

  4. Effects of processing on radionuclide content of food -implications for radiological assessments

    International Nuclear Information System (INIS)

    Green, N.; Wilkins, B.T.

    1996-01-01

    Published information on the effects of processing on the radionuclide content of food has been reviewed. Data are scarce: the majority of the available information concerns 137 Cs, 90 Sr and 131 I, with some dealing with 35 S, 210 Pb and 210 Po. For broad assessments of doses to critical groups from controlled releases, processes that can be carried out on a domestic or local scale are of greatest relevance. In this case, food can be prepared in various ways and cooking liquors can also be consumed, either directly or in the form of sauces. Consequently, when making estimates of intakes of activity, it would be reasonable to assume that, that for the majority of food items and most radionuclides, effectively no loss occurs as a result of processing, provided that the activity concentrations in the foodstuff relate to the edible portion. More information on the behaviour of potentially volatile radionuclides during cooking would however be useful. Recommendations are made about the presentation of data on food processing. (Author)

  5. Atmospheric transport of radionuclides

    International Nuclear Information System (INIS)

    Crawford, T.V.

    1977-01-01

    The chairman and contributors are members of the Working Group on Atmospheric Dispersion, Deposition, and Resuspension. This group examined the mathematical approaches for determining the direct and indirect pathways to man of releases of pollutants to the atmosphere. The dose-to-man limitations promulgated by the Nuclear Regulatory Commission, the Environmental Protection Agency, and the Energy Research and Development Administration were presented. The present status of research was discussed, and recommendations for future work were made. Particular emphasis was placed on the need for additional experimental work to develop confidence limits leading to acceptable probability statements of critical pathways for determining the dose-to-man

  6. Atmospheric transport of radionuclides

    International Nuclear Information System (INIS)

    Crawford, T.V.

    1978-01-01

    The chairman and contributors are members of the Working Group on Atmospheric Dispersion, Deposition, and Resuspension. This group examined the mathematical approaches for determining the direct and indirect pathways to man of releases of pollutants to the atmosphere. The dose-to-man limitations promulgated by the Nuclear Regulatory Commission, the Environmental Protection Agency, and the Energy Research and Development Administration were presented. The present status of research was discussed, and recommendations for future work were made. Particular emphasis was placed on the need for additional experimental work to develop confidence limits leading to acceptable probability statements of critical pathways for determining the dose-to-man

  7. Safety analysis for the Abadia de Goias repository: alternative evaluation of the ingestion dose rate critical distance; Analise de seguranca para o repositorio de Abadia de Goias: avaliacao alternativa da distancia critica de taxa de dose de ingestao

    Energy Technology Data Exchange (ETDEWEB)

    Martin Alves, A.S. de; Passos, E.M. dos [NUCLEN, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    An alternative calculation of the ingestion dose rate critical distance due to a hypothetical release of Cs-137 from the structure of the Repository of Abadia de Goias is presented. The release pathway considers the repository - groundwater region - well - and food chain. The main adopted modification comparing to the previous work is the inclusion of the convective and molecular diffusion terms in the radionuclide transport equation in addition to the radioactive decay term. (author). 6 refs, 1 tab.

  8. Inwardly Rectifying Potassium (Kir) Channels Represent a Critical Ion Conductance Pathway in the Nervous Systems of Insects.

    Science.gov (United States)

    Chen, Rui; Swale, Daniel R

    2018-01-25

    A complete understanding of the physiological pathways critical for proper function of the insect nervous system is still lacking. The recent development of potent and selective small-molecule modulators of insect inward rectifier potassium (Kir) channels has enabled the interrogation of the physiological role and toxicological potential of Kir channels within various insect tissue systems. Therefore, we aimed to highlight the physiological and functional role of neural Kir channels the central nervous system, muscular system, and neuromuscular system through pharmacological and genetic manipulations. Our data provide significant evidence that Drosophila neural systems rely on the inward conductance of K + ions for proper function since pharmacological inhibition and genetic ablation of neural Kir channels yielded dramatic alterations of the CNS spike discharge frequency and broadening and reduced amplitude of the evoked EPSP at the neuromuscular junction. Based on these data, we conclude that neural Kir channels in insects (1) are critical for proper function of the insect nervous system, (2) represents an unexplored physiological pathway that is likely to shape the understanding of neuronal signaling, maintenance of membrane potentials, and maintenance of the ionic balance of insects, and (3) are capable of inducing acute toxicity to insects through neurological poisoning.

  9. Determination of alpha radionuclides in fish

    International Nuclear Information System (INIS)

    Pernicka, L.; Matel, L.; Rosskopfova, O.

    2001-01-01

    In atmospheric water, external water and undercurrent the occurrence of radionuclides is usual. It is an important factor of quality of the environment. Plants ingest radionuclides from water and with they everyone. And it arises radioactivity infest food-chain. Radiotoxicity of this radionuclides is very deer sometimes. The sensitive radiochemical procedures for their determination are necessarily important. The poster presents the combined procedure used at our laboratory for determination of alpha radionuclides in biological samples. (authors)

  10. Migration pathways in soils

    International Nuclear Information System (INIS)

    Gronow, J.R.

    1986-01-01

    This study looked at diffusive migration through three types of deformation; the projectile pathways, hydraulic fractures of the sediments and faults, and was divided into three experimental areas: autoradiography, the determination of diffusion coefficients and electron microscopy of model projectile pathways in clay. For the autoradiography, unstressed samples were exposed to two separate isotopes, Pm-147 (a possible model for Am behaviour) and the poorly sorbed iodide-125. The results indicated that there was no enhanced migration through deformed kaolin samples nor through fractured Great Meteor East (GME) sediment, although some was evident through the projectile pathways in GME and possibly through the GME sheared samples. The scanning electron microscopy of projectile pathways in clay showed that emplacement of a projectile appeared to have no effect on the orientation of particles at distances greater than two projectile radii from the centre of a projectile pathway. It showed that the particles were not simply aligned with the direction of motion of the projectile but that, the closer to the surface of a particular pathway, the closer the particles lay to their original orientation. This finding was of interest from two points of view: i) the ease of migration of a pollutant along the pathway, and ii) possible mechanisms of hole closure. It was concluded that, provided that there is no advective migration, the transport of radionuclides through sediments containing these defects would not be significantly more rapid than in undeformed sediments. (author)

  11. Fully coupled modeling of radionuclide migration in a clayey rock disturbed by alkaline plume

    International Nuclear Information System (INIS)

    Pellegrni, D.; Windt, L. de; Lee, J.V.D.

    2002-03-01

    The disposal of radioactive wastes in clayey formations may require the use of large amounts of concrete and cement as a barrier to minimize corrosion of steel containers and radionuclide migration and for supporting drifts and disposal vaults. In this context, reactive transport modeling of the interactions between cement or concrete and the argillaceous host rock aims at estimating the evolution in time of the containment properties of the multi-barriers system. The objectives of the paper are to demonstrate that integrating radionuclides migration in the modeling of strongly coupled geochemical processes of cement-clay stone interactions is feasible and that it represents an efficient way to assess the sensitivity and modification of the classical Kd and solubility parameters with respect to the chemical evolutions. Two types of modeling are considered in the paper: i): calculation of intrinsic solubility limits and Kd values backing up on the results of modeling of cement/clay stone interactions (radionuclides are assumed to be present over the whole domain at any time whatever the scenario), ii) full mechanistic modeling which explicitly introduces radionuclides in the calculation with ad hoc assumptions on radionuclide inventory, canister failure, migration pathway, etc. The reactive transport code HYTEC, based on the geochemical code CHESS, is used to simulate both the cement-clay stone interaction processes and the radionuclide migration in 1-D and 2-D configurations. Convective/dispersive and diffuse transport can be simulated for solutes and colloids. A wide range of processes such as aqueous chemistry, redox, dissolution/precipitation, surface complexation and ion exchange can be modeled at equilibrium or with kinetic control. In addition, HYTEC is strongly coupled, i.e. the hydrology (flow and diffusion) may change when mineral precipitation or dissolution changes the local porosity. (authors)

  12. Atmospheric Pathway Screening Analysis for Saltstone Disposal Facility Vault 4

    International Nuclear Information System (INIS)

    COOK, JAMES

    2004-01-01

    A sequential screening process using a methodology developed by the National Council on Radiation Protection and Measurements, professional judgment and process knowledge has been used to produce a list of radionuclides requiring detailed analysis to derive disposal limits for the Saltstone Disposal Facility based on the atmospheric pathway

  13. Radionuclide usage survey 1979-80

    International Nuclear Information System (INIS)

    Woods, M.J.

    1980-08-01

    Details of a survey by the Life Sciences Working Group of the International Committee for Radionuclide Metrology (ICRM) on radionuclide usage by medical physicists in 11 countries are presented. The results indicate that the radionuclide which will be of most significance in the future will be F-18, Fe-52, Ga-67, Ga-68, Kr-81m, Tc-99m, In-111, I-123, Xe-127 and Tl-201, (U.K.)

  14. Criteria for requesting specific radionuclide analysis through gross α and gross β concentration measurements in environmental samples

    International Nuclear Information System (INIS)

    Ferreira, E.G.

    1988-01-01

    This paper suggests some criteria for the decision to proceed with the analysis of specific radionuclides based on results of the determination of gross α and β concentrations in environmental samples of aerosols, water, dairy and agricultural products, soil and sediments. The samples considered are provenient from the environmental surveillance of uranium mining and milling facilities as well as the mining and processing plants of monazite sands. The radionuclides to be analysed are those considered to be the most critical to human health, that is: U-nat; Th-nat; Th-230; Ra-228; Ra-226; Po-210; Pb-210. The measured gross α and β concentrations will be compared with the Maximum Allowable Concentrations for some defined radionuclides. Radiochemical analysis of specific radionuclides may then become necessary, depending upon the results of this comparison. The main goal of the proposed guide is to simplify and to discipline the execution of environmental surveillance programs in a safe and economical way, avoiding unnecessary analysis. (author) [pt

  15. Radionuclides: Accumulation and Transport in Plants.

    Science.gov (United States)

    Gupta, D K; Chatterjee, S; Datta, S; Voronina, A V; Walther, C

    Application of radioactive elements or radionuclides for anthropogenic use is a widespread phenomenon nowadays. Radionuclides undergo radioactive decays releasing ionizing radiation like gamma ray(s) and/or alpha or beta particles that can displace electrons in the living matter (like in DNA) and disturb its function. Radionuclides are highly hazardous pollutants of considerable impact on the environment, food chain and human health. Cleaning up of the contaminated environment through plants is a promising technology where the rhizosphere may play an important role. Plants belonging to the families of Brassicaceae, Papilionaceae, Caryophyllaceae, Poaceae, and Asteraceae are most important in this respect and offer the largest potential for heavy metal phytoremediation. Plants like Lactuca sativa L., Silybum marianum Gaertn., Centaurea cyanus L., Carthamus tinctorius L., Helianthus annuus and H. tuberosus are also important plants for heavy metal phytoremediation. However, transfer factors (TF) of radionuclide from soil/water to plant ([Radionuclide]plant/[Radionuclide]soil) vary widely in different plants. Rhizosphere, rhizobacteria and varied metal transporters like NRAMP, ZIP families CDF, ATPases (HMAs) family like P1B-ATPases, are involved in the radio-phytoremediation processes. This review will discuss recent advancements and potential application of plants for radionuclide removal from the environment.

  16. Method of separating short half-life radionuclides from a mixture of radionuclides

    Science.gov (United States)

    Bray, L.A.; Ryan, J.L.

    1999-03-23

    The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

  17. 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

  18. Radionuclide transport processes in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1983-01-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

  19. Liquid discharges from the use of radionuclides in medicine (diagnosis)

    International Nuclear Information System (INIS)

    Barquero, R.; Agulla, M.M.; Ruiz, A.

    2008-01-01

    The production and discharge of liquid radioactive wastes as excreta from patients undergoing Nuclear Medicine Diagnostic (NMD) in a hospital were studied. Instantaneous and accumulated activity, discharged from the hospital to the sewage system, has been estimated keeping in mind radionuclide decay. This study would enable estimation of the environmental impact due to NMD procedures. Annual accumulated activities of 2.2 GBq ( 131 I), 1.847 GBq ( 99m Tc), 0.743 GBq ( 123 I), 0.337 GBq ( 67 Ga), 0.169 GBq ( 111 In) and 0.033 GBq ( 201 Tl) result from our model when applied to a European hospital. A comparison is made with calculations by other authors that do not consider the radionuclide decay and who overestimate by two orders of magnitude. Doses to critical people as sewage treatment workers are also significantly reduced. So, our results stress the importance of including the decay in the calculations

  20. Dosimetry in radionuclide therapies with 90Y-conjugates. The IEO experience

    International Nuclear Information System (INIS)

    Cremonesi, M.; Ferrari, M.; Chinol, M.; Bartolomei, M.; Sacco, E.; Fiorenza, M.; Tosi, G.; Paganelli, G.; Stabin, M. G.

    2000-01-01

    The basis for successful radionuclide therapy is a high and stable uptake of the radiopharmaceutical in the target tissue along with low activity concentration in other normal organs. The contribution of dosimetry in radionuclide therapy is to predict before the treatment the absorbed doses in tumor and normal organs, to identify the critical organs, to minimize any possible toxicity and to evaluate the maximum tolerated dose. In this article is reported the experience concerning pharmacokinetics and dosimetry of two 90 Y-therapeutic protocols: 3-step pretargeting radioimmunotherapy (RIT) according to the biotin-avidin system and receptor mediated radionuclide therapy with the somatostatin analogue (DOTA-D-Phe 1 -Tyr 3 ) octreotide named DOTATOC. For the dosimetric analysis, analogous approaches for the two radiolabeled compounds due to the similar pharmacokinetic characteristics were adopted; the MIRD formalism was applied, taking into account both the physical and the biological characteristics of the radio conjugate and patients' metabolism. In order to determine biological clearance, serial blood samples and complete urine collection were obtained up to 48 hours after injection; to evaluate biodistribution, several whole body scans were acquired. Both therapies showed the advantageous characteristics of a fast blood clearance and a predominantly renal excretion of the radiopharmaceuticals thus lowering the irradiation of the total body. Although pharmacokinetic characteristics were similar, different critical organs were found for the two therapies: in particular, some considerations regarding red marrow, spleen and kidneys were required. The results of the studies indicate that high activities of 90 Y-biotin (3-step RIT) and 90 Y-DOTATOC can be administered with acceptable radiation doses to normal organs

  1. 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

  2. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

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

  4. Artificial radionuclides in soil, flora and fauna

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Sources and ways of soil contamination by radionuclides, as well as the main regularities of radionuclide behaviour in soils, are discussed. Ways of radionuclide uptake by plants are discussed in detail, since radionuclide contamination of vegetation, and agricultural plants and pastures in particular, is one of the main factors, determining sanitary value of environmental contamination by radioactive substances

  5. Simple evaluation of groundwater flow and radionuclide transport at Aespoe

    International Nuclear Information System (INIS)

    Dverstorp, B.; Geier, J.; Voss, C.

    1996-12-01

    A simple evaluation of groundwater flux and potential for radionuclide transport at the Aespoe site, from fundamental hydrologic principles, indicates that, based upon data that are available from surface-based investigations, it is not possible to confirm that the bedrock has a high capacity to retard radionuclide release to the surface environment. This result is primarily due to the high spatial variability of hydraulic conductivity, and high uncertainty regarding the relationship among hydrologic and transport parameters within conductive elements of the bedrock. A comparison between Aespoe and seven other study sites in Sweden indicates that it is difficult or impossible to discriminate among these sites in terms of the geologic barrier function, based upon the types of data that are available from present-day methods of site characterization. Groundwater flux is evaluated by a one-dimensional application of Darcy's law to a set of simple, potential pathways for groundwater flow from the repository, which are chosen to yield an appraisal of the wide bounds of possible system behaviour. The configurations of the pathways are specified based on simple assumptions of flow-field structure, and hydraulic driving forces are specified from consideration of regional and local topographic differences. Results are expressed in terms of a parameter group that has been shown to control the barrier function. Comparisons with more detailed hydrological modelling of Aespoe show that, although a reduction in uncertainty is achieved, this reduction is not sufficient to distinguish between good and poor performance of the geologic barrier at the site. 38 refs

  6. The relative importance of ingestion for multiple pathway dose assessments

    International Nuclear Information System (INIS)

    Wicker, W.; Grogan, H.; Bergstroem, U.; Hoffman, O.

    1991-01-01

    The general purpose of this report is to examine the relative importance of ingestion pathways, and particularly food chain transport in overall dose assessment. The importance of ingestion pathways is examined for various release scenarios and radionuclides because the findings are expected to differ with circumstances. The degree to which contaminated food products contribute to the total dose will affect the importance of accuracy and uncertainty of food chain model predictions, which is the main thrust of the Biospheric Model Validation Study (BIOMOVS). This analysis requires that all modes of radiation exposure be examined, including inhalation, external exposure, and the various ingestion pathways. (2 figs., 2 tabs.)

  7. Environmental behaviour of radionuclides and transfer to man

    International Nuclear Information System (INIS)

    Smith, H.

    1982-01-01

    The environmental behaviour of the radionuclides making the major contribution to man's irradiation through diet is described. The following stages are emphasized: transfer of radionuclides to plants; transfer of radionuclides to animals; metabolism of inhaled or ingested radionuclides in animals providing food for man; transfer of radionuclides through the aquatic environment; application of food chain models. (43 references)

  8. 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

  9. Inverse problem in radionuclide transport

    International Nuclear Information System (INIS)

    Yu, C.

    1988-01-01

    The disposal of radioactive waste must comply with the performance objectives set forth in 10 CFR 61 for low-level waste (LLW) and 10 CFR 60 for high-level waste (HLW). To determine probable compliance, the proposed disposal system can be modeled to predict its performance. One of the difficulties encountered in such a study is modeling the migration of radionuclides through a complex geologic medium for the long term. Although many radionuclide transport models exist in the literature, the accuracy of the model prediction is highly dependent on the model parameters used. The problem of using known parameters in a radionuclide transport model to predict radionuclide concentrations is a direct problem (DP); whereas the reverse of DP, i.e., the parameter identification problem of determining model parameters from known radionuclide concentrations, is called the inverse problem (IP). In this study, a procedure to solve IP is tested, using the regression technique. Several nonlinear regression programs are examined, and the best one is recommended. 13 refs., 1 tab

  10. Determination of radionuclide solubility limits to be used in SR 97. Uncertainties associated to calculated solubilities

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, J.; Cera, E.; Duro, L.; Jordana, S. [QuantiSci S.L., Barcelona (Spain); Pablo, J. de [DEQ-UPC, Barcelona (Spain); Savage, D. [QuantiSci Ltd., Henley-on-Thames (United Kingdom)

    1997-12-01

    The thermochemical behaviour of 24 critical radionuclides for the forthcoming SR97 PA exercise is discussed. The available databases are reviewed and updated with new data and an extended database for aqueous and solid species of the radionuclides of interest is proposed. We have calculated solubility limits for the radionuclides of interest under different groundwater compositions. A sensitivity analysis of the calculated solubilities with the composition of the groundwater is presented. Besides selecting the most likely solubility limiting phases, in this work we have used coprecipitation approaches in order to calculate more realistic solubility limits for minor radionuclides, such as Ra, Am and Cm. The comparison between the calculated solubilities and the concentrations measured in relevant natural systems (NA) and in spent fuel leaching experiments helps to assess the validity of the methodology used and to derive source term concentrations for the radionuclides studied. The uncertainties associated to the solubilities of the main radionuclides involved in the spent nuclear fuel have also been discussed in this work. The variability of the groundwater chemistry; redox conditions and temperature of the system have been considered the main factors affecting the solubilities. In this case, a sensitivity analysis has been performed in order to study solubility changes as a function of these parameters. The uncertainties have been calculated by including the values found in a major extent in typical granitic groundwaters. The results obtained from this analysis indicate that there are some radionuclides which are not affected by these parameters, i.e. Ag, Cm, Ho, Nb, Ni, Np, Pu, Se, Sm, Sn, Sr, Tc and U

  11. Physico-chemical and hydraulic mechanisms of radionuclide mobilization in aquatic systems

    International Nuclear Information System (INIS)

    Konoplev, A.V.; Bulgakov, A.A.; Comans, R.N.J.; Hilton, J.; Smith, J.; Madruga, M.J.; Voitsekhovich, O.V.; Sansone, U.; Kudelsky, A.V.

    1996-01-01

    This paper presents main results of joint studies carried out in frame of EC-coordinated ECP-3 Project 'Modelling and study of the mechanisms of the transfer of radioactive material from the terrestrial ecosystem to and in water bodies around Chernobyl' in part of geochemical pathways. Physico-chemical models of specific migration processes are developed and recommended for application as sub models for inclusion in the decision support system (JSP-1). Main parameters, determining the behaviour of radionuclides in aquatic ecosystems are identified and methods for their estimation in |emergency situations are proposed

  12. Nevada Test Site National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2008

    International Nuclear Information System (INIS)

    Warren, Ronald; Grossman, Robert F.

    2009-01-01

    The Nevada Test Site (NTS) is operated by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office. From 1951 through 1992, the NTS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NTS activities has been monitored since the initiation of atmospheric testing. Limitation to under-ground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NTS. After nuclear testing ended in 1992, NTS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by winds) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of tritium were also emitted to air at the North Las Vegas Facility (NLVF), an NTS support complex in the city of North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations (CFR) Part 61 Subpart H) (CFR, 2008a) limits the release of radioactivity from a U.S. Department of Energy facility (e.g., the NTS) to 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation not related to NTS activities. Unrelated doses could come from naturally occurring radioactive elements or from other man-made sources such as medical treatments. The NTS demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations. This method was approved by the U.S. Environmental Protection Agency for use on the NTS in 2001 and has been the sole method used since 2005. Six locations on the NTS have been established to act as critical receptor locations to demonstrate compliance with the NESHAP limit. These locations are actually pseudo-critical

  13. 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

  14. Use of critical pathway models and log-normal frequency distributions for siting nuclear facilities

    International Nuclear Information System (INIS)

    Waite, D.A.; Denham, D.H.

    1975-01-01

    The advantages and disadvantages of potential sites for nuclear facilities are evaluated through the use of environmental pathway and log-normal distribution analysis. Environmental considerations of nuclear facility siting are necessarily geared to the identification of media believed to be sifnificant in terms of dose to man or to be potential centres for long-term accumulation of contaminants. To aid in meeting the scope and purpose of this identification, an exposure pathway diagram must be developed. This type of diagram helps to locate pertinent environmental media, points of expected long-term contaminant accumulation, and points of population/contaminant interface for both radioactive and non-radioactive contaminants. Confirmation of facility siting conclusions drawn from pathway considerations must usually be derived from an investigatory environmental surveillance programme. Battelle's experience with environmental surveillance data interpretation using log-normal techniques indicates that this distribution has much to offer in the planning, execution and analysis phases of such a programme. How these basic principles apply to the actual siting of a nuclear facility is demonstrated for a centrifuge-type uranium enrichment facility as an example. A model facility is examined to the extent of available data in terms of potential contaminants and facility general environmental needs. A critical exposure pathway diagram is developed to the point of prescribing the characteristics of an optimum site for such a facility. Possible necessary deviations from climatic constraints are reviewed and reconciled with conclusions drawn from the exposure pathway analysis. Details of log-normal distribution analysis techniques are presented, with examples of environmental surveillance data to illustrate data manipulation techniques and interpretation procedures as they affect the investigatory environmental surveillance programme. Appropriate consideration is given these

  15. Analyses of human exposures to alpha-emitting radionuclides from nuclear fuel cycles

    International Nuclear Information System (INIS)

    Cuddihy, R.G.; McClellan, R.O.; Griffith, W.C.; Hoover, M.D.

    1977-01-01

    Human populations may potentially be exposed to alpha-emitting radionuclides released to the environment from a variety of activities associated with nuclear fuel cycles. Generally, the most important exposure pathway is by way of inhalation. This can occur soon after release of these substances or after they have been deposited on ground surfaces and resuspended with soil particles. Estimating the potential magnitude of these exposures is usually done through the use of mathematical models accounting for the dispersion of the released material through the environment and its uptake by people living near the nuclear facilities. Studies described in this paper suggest that these exposures can probably be estimated within a factor of 10 based upon our previous experience with measured human organ levels of other trace metals taken up from the environment. It should also be noted that variability among individuals within the population may result in a few percent accumulating more than 10 times the geometric mean of the internal organ radionuclide burdens

  16. Definition of critical periods for Hedgehog pathway antagonist-induced holoprosencephaly, cleft lip, and cleft palate.

    Directory of Open Access Journals (Sweden)

    Galen W Heyne

    Full Text Available The Hedgehog (Hh signaling pathway mediates multiple spatiotemporally-specific aspects of brain and face development. Genetic and chemical disruptions of the pathway are known to result in an array of structural malformations, including holoprosencephaly (HPE, clefts of the lip with or without cleft palate (CL/P, and clefts of the secondary palate only (CPO. Here, we examined patterns of dysmorphology caused by acute, stage-specific Hh signaling inhibition. Timed-pregnant wildtype C57BL/6J mice were administered a single dose of the potent pathway antagonist vismodegib at discrete time points between gestational day (GD 7.0 and 10.0, an interval approximately corresponding to the 15th to 24th days of human gestation. The resultant pattern of facial and brain dysmorphology was dependent upon stage of exposure. Insult between GD7.0 and GD8.25 resulted in HPE, with peak incidence following exposure at GD7.5. Unilateral clefts of the lip extending into the primary palate were also observed, with peak incidence following exposure at GD8.875. Insult between GD9.0 and GD10.0 resulted in CPO and forelimb abnormalities. We have previously demonstrated that Hh antagonist-induced cleft lip results from deficiency of the medial nasal process and show here that CPO is associated with reduced growth of the maxillary-derived palatal shelves. By defining the critical periods for the induction of HPE, CL/P, and CPO with fine temporal resolution, these results provide a mechanism by which Hh pathway disruption can result in "non-syndromic" orofacial clefting, or HPE with or without co-occurring clefts. This study also establishes a novel and tractable mouse model of human craniofacial malformations using a single dose of a commercially available and pathway-specific drug.

  17. Assessment of hydrologic transport of radionuclides from the Rio Blanco underground nuclear test site, Colorado

    International Nuclear Information System (INIS)

    Chapman, J.; Earman, S.; Andricevic, R.

    1996-10-01

    DOE is operating an environmental restoration program to characterize, remediate, and close non-Nevada Test Site locations used for nuclear testing. Evaluation of radionuclide transport by groundwater is part of preliminary risk analysis. These evaluations allow prioritization of test areas in terms of risk, provide a basis for discussions with regulators and the public about future work, and provide a framework for assessing site characterization data needs. The Rio Blanco site in Colorado was the location of the simultaneous detonation of three 30-kiloton nuclear devices. The devices were located 1780, 1899, and 2039 below ground surface in the Fort Union and Mesaverde formations. Although all the bedrock formations at the site are thought to contain water, those below the Green River Formation (below 1000 in depth) are also gas-bearing, and have very low permeabilities. The transport scenario evaluated was the migration of radionuclides from the blast-created cavity through the Fort Union Formation. Transport calculations were performed using the solute flux method, with input based on the limited data available for the site. Model results suggest that radionuclides from the test are contained entirely within the area currently administered by DOE. This modeling was performed to investigate how the uncertainty in various physical parameters affect radionuclide transport at the site, and to serve as a starting point for discussion regarding further investigation; it was not intended to be a definitive simulation of migration pathways or radionuclide concentration values. Given the sparse data, the modeling results may differ significantly from reality. Confidence in transport predictions can be increased by obtaining more site data, including the amount of radionuclides which would have been available for transport (i.e., not trapped in melt glass or vented during gas flow testing), and the hydraulic properties of the formation. 38 refs., 6 figs., 1 tab

  18. Modelling for radiological and radioecological consequences of an accidental radionuclide release at Sea

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1997-01-01

    Full text: Scenarios concerning accidental releases of radionuclides into water bodies can be found in the open literature, mostly in connection with nuclear power plants located either onshore or inland. However, meager attention has been given to nuclear reactors used as energy sources for propulsion at sea, which are also subject to accidents. Such potential accidents may involve the loss of part of the reactor core to the surrounding water body. In addition of the initial instantaneous releases, one can estimate delayed source terms based on the rate at which radionuclides are dissolved or leached from the solidified material, like part of the core or structural materials in contact with water. Most of such solidified material might be a mixture of uranium, zirconium, iron, calcium, silica, fission and activation products, and transuranium elements as oxides, forming a glassy type solid. Transport models were used to calculate radionuclide concentrations in water resulting from short and delayed source terms. Oceanographic data used in the calculations were taken either from the open literature or from unclassified reports of the Brazilian Navy, being, however, as generic as possible. Time-dependent concentration functions for radionuclides in aquatic food following an accidental release reflect the net result of intake and elimination processes. However, to avoid the complexities of multiple parameters involved in such processes, the model accounts only for trophic transfer of radionuclides, and yet avoids the necessity of analyzing the details of each transfer step used to determine fish, crustacea, molluscs and seaweed accumulation. Swimming and other aquatic sports are not included in the model used for dose calculations because of theirs relatively low importance in comparison with the pathways concerning ingestion of aquatic food

  19. Measurement of radionuclides in waste packages

    Science.gov (United States)

    Brodzinski, R.L.; Perkins, R.W.; Rieck, H.G.; Wogman, N.A.

    1984-09-12

    A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

  20. Mathematical simulation of sediment and contaminant transport in surface waters. Annual report, October 1977--September 1978

    International Nuclear Information System (INIS)

    Onishi, Y.; Arnold, E.M.; Serne, R.J.; Cowan, C.E.; Thompson, F.L.; Mayer, D.W.

    1979-01-01

    Various pathways exist for exposure of humans and biota to radioactive materials released from nuclear facilities. Hydrologic transport (liquid pathway) is one element in the evaluation of the total radiation dose to man. Mathematical models supported by well-planned field data collection programs can be useful tools in assessing the hydrologic transport and ultimate fate of radionuclides. Radionuclides with high distribution coefficients or radionuclides in surface waters with high suspended sediment concentrations are, to a great extent, adsorbed by river and marine sediments. Thus, otherwise dilute contaminants are concentrated. Contaminated sediments may be deposited on the river and ocean beds creating a significant pathway to man. Contaminated bed sediment in turn may become a long-term source of pollution through desorption and resuspension. In order to assess migration and accumulation of radionuclides in surface waters, mathematical models must correctly simulate essential mechanisms of radionuclide transport. The objectives of this study were: (1) to conduct a critical review of (a) radionuclide transport models as well as sediment transport and representative water quality models in rivers, estuaries, oceans, lakes, and reservoirs, and (b) adsorption and desorption mechanisms of radionuclides with sediments in surface waters; (2) to synthesize a mathematical model capable of predicting short- and long-term transport and accumulation of radionuclides in marine environments

  1. Limitation of radioactive discharges from NPP based on radionuclide specific monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bucina, I; Malatova, I; Vidlakova, J [National Radaition Protection Institute, Prague (Czech Republic)

    1996-12-31

    Monitoring of nuclear power plants (NPP) discharges into atmosphere and hydrosphere based on particulate-iodine-gas (PIG) measurements and gross beta and gamma plus tritium measurements respectively is being improved by nuclide specific measurements employing semiconductor gamma and alpha spectrometry and radiochemical methods. In connection with the progress new concept of authorized effluent limits and the related regulations is being implemented in the Czech Republic. Activities of all principally contributing to the effective dose radionuclides discharges during a year multiplied by a Sv/Bq conversion coefficient based on a standard model are summed up and the effective dose is compared with the new limit. These limits should be authorized for discharges into atmosphere as per caput collective committed effective dose in the NPP surrounding or as its value multiplied by the number of surrounding segment providing thus committed effective dose to member of a vital critical group and into the hydrosphere as committed effective dose to the critical group member. The criteria for obligatory evaluation of the specific radionuclide contribution and the resulting requirements on minimum detectable activities for both the shorter and longer monitoring intervals are included in the new regulations. The PIG and gross activity measurement results will be compared with investigation levels only and no more used for limitation purposes. (authors).

  2. Resettlement of Bikini Atoll U.S. Nuclear Test Site

    International Nuclear Information System (INIS)

    Robinson, W.L.; Conrado, C.L.; Stuart, M.L.; Stoker, A.C.; Hamilton, T.F.

    1999-01-01

    The US conducted a nuclear testing program at Bikini and Enewetak Atolls in the Marshall Islands from 1946 through 1958. Several atolls, including Bikini, were contaminated as a result of the nuclear detonations. Since 1974 the authors have conducted an extensive research and monitoring program to determine the radiological conditions at the atolls, identify the critical radionuclides and pathways, estimate the radiological dose to current or resettling populations, and develop remedial measures to reduce the dose to atoll populations. This paper describes exposure pathways and radionuclides; composition of atoll soils; radionuclide transport and dose estimates; remedial measures; and reduction in dose from a combined option

  3. Pathways and estimated consequences of radionuclide releases from a nuclear power plant

    International Nuclear Information System (INIS)

    Nilsson, Mats.

    1981-03-01

    The radioactive corrosion products 60 Co, 58 Co, 54 Mn, 65 Zn, 51 Cr and 110 Agsp(m) which are released from Barsebaeck Nuclear Power Plant (Sweden) into the marine environment have been studied. The brown seaweed Fucus vesiculosus has been found to be excellent bioindicator for these radionuclides. The distribution of activation products along the west coast of Sweden has been studied and can very well be described with a power function. Uptake and retention of the activation products in Fucus have been studied and results are reported. The activity concentration in Fucus well reflects the disharge rate from the power plant. Other bioindicators have been studied ; mainly the crustaceans Idothea and Gammarus. A simulation of 131 I-release following a fictious BWR 1 accident is described as well as a model for estimation of the individual and collective dose equivalents arising from intake of contaminated milk. (Author)

  4. Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry

    International Nuclear Information System (INIS)

    Gbadago, J K; Darko, E O; Faanhof, A; Schandorf, C

    2011-01-01

    The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits. The environmental impact of the radionuclides is therefore expected to be low in this mining environment.

  5. Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gbadago, J K; Darko, E O [Ghana Atomic Energy Commission, PO Box LG 80, Legon, Accra (Ghana); Faanhof, A [South African Nuclear Energy Corporation, PO Box 582, Pretoria 0001 (South Africa); Schandorf, C, E-mail: jgbada@yahoo.com [School of Nuclear and Allied Sciences, University of Ghana, Legon, Accra (Ghana)

    2011-09-01

    The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits. The environmental impact of the radionuclides is therefore expected to be low in this mining environment.

  6. Speciation of radionuclides in the environment

    International Nuclear Information System (INIS)

    Gunten, H.R. von; Benes, P.

    1994-02-01

    Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g. by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e. in the atmosphere, hydrosphere and lithosphere. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions). (author)

  7. Radionuclide transport in a single fissure

    International Nuclear Information System (INIS)

    Eriksen, T.E.

    1983-01-01

    Radionuclide migration have been studied in natural fissures orieted parallel to the axis of granite drill cores. A short pulse of the radionuclides solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. After several hundred fissure volumes water had been pumped through the fissure following the radionuclide pulse the activity distribution on the fissure surfaces was measured. From the retardation of 152 Eu, 235 Np and 237 Pu it is concluded that these radionuclides are transported in the oxidation states Eu(III), Pu(IV) and Np(V). The distribution coefficients K sub (d) calculated from flow and activity distribution data on the basis of geometric surface area/volume ratios are of the same order as published K sub (d) values obtained from batch equilibrium experiments. (Author)

  8. Environmental pathways and radiological dosimetry for biota

    International Nuclear Information System (INIS)

    Blaylock, B.G.

    1997-01-01

    Radionuclides entering the environment as a result man's activities may be transported, cycled, and/or concentrated in the biotic and abiotic compartments of the ecosystem. Organisms in an environment contaminated with radioactive waste may be irradiated externally by radionuclides in air, water, vegetation, soil or sediment and internally by radionuclides accumulated within their bodies by inhalation or by direct absorption through their skin. The purpose of this paper is to examine the pathways in which biota are exposed to radioactive releases to the environment and to review the methods used to calculate radiation doses to the biota. In general, the methodology for estimating radiation doses to biota in their natural environment is better developed for aquatic biota than for terrestrial biota. The different methodologies which have been used for calculating radiation doses to aquatic biota were reviewed. If the protection of non-human biota is an issue in addressing environmental assessments of nuclear facilities, then the methodology for estimating radiation doses to biota should be improved. It is recommended that dose calculations should be simplified and standardized by developing dose conversion factors for a number of generic aquatic and terrestrial organisms. (author)

  9. Measurement of anthropogenic radionuclides in the atmosphere with a radionuclide monitoring network for nuclear tests

    International Nuclear Information System (INIS)

    Yonezawa, Chushiro; Yamamoto, Yoichi

    2011-01-01

    A worldwide radionuclide monitoring network for nuclear tests has detected the anthropogenic radioactive materials released in the atmosphere due to the accident of the Fukushima Daiichi Nuclear Power Plant impacted by the Great East Japan Earthquake on March 11, 2011. After four months have passed since the accident occurred, most overseas stations do not detect the radionuclides of Fukushima origin any more. The Takasaki station in Japan, however, is still detecting them every day. This paper describes radionuclide monitoring stations and the network of them as part of the International Monitoring System (IMS) in the Comprehensive Nuclear Test Ban Treaty (CTBT), as well as the measurement results of radionuclide particulates and radioactive isotopes of xenon released from the Fukushima Daiichi Nuclear Power Plant with the monitoring network. (J.P.N.)

  10. 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)

  11. A vector Wiener filter for dual-radionuclide imaging

    International Nuclear Information System (INIS)

    Links, J.M.; Prince, J.L.; Gupta, S.N.

    1996-01-01

    The routine use of a single radionuclide for patient imaging in nuclear medicine can be complemented by studies employing two tracers to examine two different processes in a single organ, most frequently by simultaneous imaging of both radionuclides in two different energy windows. In addition, simultaneous transmission/emission imaging with dual-radionuclides has been described, with one radionuclide used for the transmission study and a second for the emission study. There is thus currently considerable interest in dual-radionuclide imaging. A major problem with all dual-radionuclide imaging is the crosstalk between the two radionuclides. Such crosstalk frequently occurs, because scattered radiation from the higher energy radionuclide is detected in the lower energy window, and because the lower energy radionuclide may have higher energy emissions which are detected in the higher energy window. The authors have previously described the use of Fourier-based restoration filtering in single photon emission computed tomography (SPECT) and positron emission tomography (PET) to improve quantitative accuracy by designing a Wiener or other Fourier filter to partially restore the loss of contrast due to scatter and finite spatial resolution effects. The authors describe here the derivation and initial validation of an extension of such filtering for dual-radionuclide imaging that simultaneously (1) improves contrast in each radionuclide's direct image, (2) reduces image noise, and (3) reduces the crosstalk contribution from the other radionuclide. This filter is based on a vector version of the Wiener filter, which is shown to be superior [in the minimum mean square error (MMSE) sense] to the sequential application of separate crosstalk and restoration filters

  12. Gas and aerosol radionuclide transfers in complex environments: experimental studies of atmospheric dispersion and interfaces exchanges

    International Nuclear Information System (INIS)

    Maro, Denis

    2011-01-01

    In situations of chronic or accidental releases, the atmosphere is the main pathway of radioactive releases from nuclear facilities to the environment and, consequently, to humans. It is therefore necessary to have sufficient information on this pathway to accurately assess the radiological impact on man and his environment. Institute for Radioprotection and Nuclear Safety develops its own tools of dispersion and atmospheric transfer for its expertise, under normal operation conditions of a facility, but especially in crisis or post-accident. These tools must have a national and international recognition in particular through scientific validation against benchmark experiments performed internationally, nationally or within the IRSN. The Radioecology Laboratory of Cherbourg-Octeville provides, and will increasingly make, a significant contribution to the scientific influence of the Institute in this field. The work presented in this report has contributed to the development or improvement of experimental techniques in the fields of atmospheric dispersion of radionuclides and transfer at interfaces, in complex environments (complex topography, urban area). These experimental techniques, applied during field campaigns, have allowed to acquire new data in order to get a better understanding of radionuclide transfers in the form of gases and aerosols. (author)

  13. Radionuclides in Canada goose eggs

    International Nuclear Information System (INIS)

    Rickard, W.H.; Sweany, H.A.

    1975-01-01

    Low levels of radionuclides were measured in Canada goose eggs taken from deserted nests from Columbia River islands on the Energy Research and Development Administration's Hanford Reservation. Potassium-40, a naturally occurring radionuclide, was the most abundant radionuclide measured in egg contents and egg shell. Strontium-90 was incorporated into egg shells and cesium-137 into inner egg contents. Manganese-54, cobalt-60, and zinc-65 were more abundant in inner egg contents than in egg shell. Cerium-144 was detected in egg shell but not in inner shell

  14. Observation-based estimate of the Fukushima radionuclide in the North Pacific

    Science.gov (United States)

    Yoshida, Sachiko; Jayne, Steven; Macdonald, Alison; Buesseler, Ken; Rypina, Irina

    2014-05-01

    Contaminated waters from Fukushima nuclear power plant (FNPP) were discharged directly into the North Pacific Ocean in March 2011. Coastal current system in this region and time scale of the water exchange with the open ocean is not well understood, however both observational evidence and numerical model simulation results indicate relatively rapid advection of contaminants eastward into the highly energetic mixed water region in the confluence of the Kuroshio and Oyashio. Surface drifters deployed near the FNPP in early summer 2011 show trajectories crossing the North Pacific generally following the large scale ocean circulation after one year. Previously obtained cesium (Cs) samples from multiple cruises near FNPP and off shore region between 2011 and 2013 are collected and evaluated to diagnose the propagating Cs signal crossing North Pacific Ocean. In this presentation, we use radionuclides of Fukushima origin as a tracer to understand the North Pacific circulation and mixing process after two years of release. Large numbers of the observation are repeatedly took place near shore where Cs shows still relatively higher about 10-30 Bq/m3 in 2013. Temperature-salinity (T-S) properties for the available hydrographic data indicate that the majority of the samples were obtained in the region where the water is highly influenced by the warm-salty Kuroshio origin water. Depth profiles of 35N section in March-May 2013 cruise of the U.S. Climate Variability and Predictability and Carbon (CLIVAR) repeat Hydrography sections are examined to track the radionuclide penetration into the subsurface ocean and the subduction pathways along isopycnal surfaces. Available large drifter datasets that accumulated over decades of field work can guide us in estimating the spread of these radionuclides. By applying an innovative statistical analysis to the drifter data, we investigate the spreading of radionuclides in the Pacific Ocean over 5-year time scales.

  15. Sensors and Automated Analyzers for Radionuclides

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.

    2003-01-01

    The production of nuclear weapons materials has generated large quantities of nuclear waste and significant environmental contamination. We have developed new, rapid, automated methods for determination of radionuclides using sequential injection methodologies to automate extraction chromatographic separations, with on-line flow-through scintillation counting for real time detection. This work has progressed in two main areas: radionuclide sensors for water monitoring and automated radiochemical analyzers for monitoring nuclear waste processing operations. Radionuclide sensors have been developed that collect and concentrate radionuclides in preconcentrating minicolumns with dual functionality: chemical selectivity for radionuclide capture and scintillation for signal output. These sensors can detect pertechnetate to below regulatory levels and have been engineered into a prototype for field testing. A fully automated process monitor has been developed for total technetium in nuclear waste streams. This instrument performs sample acidification, speciation adjustment, separation and detection in fifteen minutes or less

  16. Parameters used in the environmental pathways (DESCARTES) and radiological dose (CIDER) modules of the Hanford Environmental Dose Reconstruction Integrated Codes (HEDRIC) for the air pathway

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S.F.; Farris, W.T.; Napier, B.A.; Ikenberry, T.A.; Gilbert, R.O.

    1992-09-01

    This letter report is a description of work performed for the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project was established to estimate the radiation doses to individuals resulting from releases of radionuclides from the Hanford Site since 1944. This work is being done by staff at Battelle, Pacific Northwest Laboratories (Battelle) under a contract with the Centers for Disease Control (CDC) with technical direction provided by an independent Technical Steering Panel (TSP). The objective of this report is to-document the environmental accumulation and dose-assessment parameters that will be used to estimate the impacts of past Hanford Site airborne releases. During 1993, dose estimates made by staff at Battelle will be used by the Fred Hutchinson Cancer Research Center as part of the Hanford Thyroid Disease Study (HTDS). This document contains information on parameters that are specific to the airborne release of the radionuclide iodine-131. Future versions of this document will include parameter information pertinent to other pathways and radionuclides.

  17. Parameters used in the environmental pathways (DESCARTES) and radiological dose (CIDER) modules of the Hanford Environmental Dose Reconstruction Integrated Codes (HEDRIC) for the air pathway

    International Nuclear Information System (INIS)

    Snyder, S.F.; Farris, W.T.; Napier, B.A.; Ikenberry, T.A.; Gilbert, R.O.

    1992-09-01

    This letter report is a description of work performed for the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project was established to estimate the radiation doses to individuals resulting from releases of radionuclides from the Hanford Site since 1944. This work is being done by staff at Battelle, Pacific Northwest Laboratories (Battelle) under a contract with the Centers for Disease Control (CDC) with technical direction provided by an independent Technical Steering Panel (TSP). The objective of this report is to-document the environmental accumulation and dose-assessment parameters that will be used to estimate the impacts of past Hanford Site airborne releases. During 1993, dose estimates made by staff at Battelle will be used by the Fred Hutchinson Cancer Research Center as part of the Hanford Thyroid Disease Study (HTDS). This document contains information on parameters that are specific to the airborne release of the radionuclide iodine-131. Future versions of this document will include parameter information pertinent to other pathways and radionuclides

  18. Risk governance on radionuclide contamination in food in Japan

    International Nuclear Information System (INIS)

    Sekizawa, Jun

    2012-01-01

    A large scale nuclear power plant accident happened after the great earthquake in Fukushima in March 2011. There was several critical mismanagement of the accident which resulted in the radio-nuclides release in the environment. Furthermore the information delay and the lack in delivery of clear and comprehensible explanation of the risk have been causing huge anxieties and worries among people living near to the site, and also people in the nation. Risk assessment appeared not to meet appropriately requests of risk management authorities and also people. Author has been trying to straighten the large amounts of data on radionuclide contamination in foods so as for people to easily understand the real situation with succinct messages explaining risk and to take appropriate actions in facing the risk. Appropriate responses and coordination among the risk managing authorities are indispensable especially in this kind of huge accident which may entail vast scale and long lasting risk and a new paradigm of the food safety governance is required in Japan. (author)

  19. Radionuclide deposition control

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

  20. Radionuclide transfer

    International Nuclear Information System (INIS)

    Gerber, G.B.

    1993-01-01

    The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG) [de

  1. Radionuclides in the study of marine processes

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Woodhead, D.S.

    1991-01-01

    For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. The primary objective of the symposium is to provide a forum for an open discussion of the insights concerning processes in the marine environment which can be gained from studies of radionuclide behaviour. Papers have been grouped within the following principal themes; the uses of radionuclides as tracers of water transport; scavenging and particulate transport processes in the oceans as deduced from radionuclide behaviour; processes in the seabed and radionuclides in biological systems. (Author)

  2. Chemical speciation of radionuclides migrating in groundwaters

    International Nuclear Information System (INIS)

    Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

    1994-04-01

    In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

  3. Critical Dose of Internal Organs Internal Exposure - 13471

    Energy Technology Data Exchange (ETDEWEB)

    Grigoryan, G.; Amirjanyan, A. [Nuclear and Radiation Safety Centre (Armenia); Grigoryan, N. [Yerevan State Medical University 4Tigran Mets,375010 Yerevan (Armenia)

    2013-07-01

    The health threat posed by radionuclides has stimulated increased efforts to developed characterization on the biological behavior of radionuclides in humans in all ages. In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age specific biokinetic models for environmentally important radioelements. Radioactive substances in the air, mainly through the respiratory system and digestive tract, is inside the body. Radioactive substances are unevenly distributed in various organs and tissues. Therefore, the degree of damage will depend not only on the dose of radiation have but also on the critical organ, which is the most accumulation of radioactive substances, which leads to the defeat of the entire human body. The main objective of radiation protection, to avoid exceeding the maximum permissible doses of external and internal exposure of a person to prevent the physical and genetic damage people. The maximum tolerated dose (MTD) of radiation is called a dose of radiation a person in uniform getting her for 50 years does not cause changes in the health of the exposed individual and his progeny. The following classification of critical organs, depending on the category of exposure on their degree of sensitivity to radiation: First group: the whole body, gonads and red bone marrow; Second group: muscle, fat, liver, kidney, spleen, gastrointestinal tract, lungs and lens of the eye; The third group: bone, thyroid and skin; Fourth group: the hands, forearms, feet. MTD exposure whole body, gonads and bone marrow represent the maximum exposures (5 rem per year) experienced by people in their normal activities. The purpose of this article is intended dose received from various internal organs of the radionuclides that may enter the body by inhalation, and gastrointestinal tract. The biokinetic model describes the time dependent distribution and excretion of different

  4. Mobility and Bioavailability of Radionuclides in Soils

    International Nuclear Information System (INIS)

    Iurian, A.; Olufemi Phaneuf, M.; Mabit, L.

    2016-01-01

    It is crucial to understand the behavior of radionuclides in the environment, their potential mobility and bioavailability related to long-term persistence, radiological hazards, and impact on human health. Such key information is used to develop strategies that support policy decisions. The environmental behavior of radionuclides depends on ecosystem characteristics. A given soil’s capacity to immobilize radionuclides has been proved to be the main factor responsible for their resulting activity concentrations in plants. The mobility and bioavailability of radionuclides in soils is complex, depending on clay-sized soil fraction, clay mineralogy, organic matter, cation exchange capacity, pH and quantities of competing cations. Moreover, plant species have different behaviors regarding radionuclide absorption depending on soil and plan characteristics

  5. Radionuclides deposition over Antarctica

    International Nuclear Information System (INIS)

    Pourchet, M.; Magand, O.; Frezzotti, M.; Ekaykin, A.; Winther, J.-G.

    2003-01-01

    A detailed and comprehensive map of the distribution patterns for both natural and artificial radionuclides over Antarctica has been established. This work integrates the results of several decades of international programs focusing on the analysis of natural and artificial radionuclides in snow and ice cores from this polar region. The mean value (37±20 Bq m -2 ) of 241 Pu total deposition over 28 stations is determined from the gamma emissions of its daughter 241 Am, presenting a long half-life (432.7 yrs). Detailed profiles and distributions of 241 Pu in ice cores make it possible to clearly distinguish between the atmospheric thermonuclear tests of the fifties and sixties. Strong relationships are also found between radionuclide data ( 137 Cs with respect to 241 Pu and 210 Pb with respect to 137 Cs), make it possible to estimate the total deposition or natural fluxes of these radionuclides. Total deposition of 137 Cs over Antarctica is estimated at 760 TBq, based on results from the 90-180 deg. East sector. Given the irregular distribution of sampling sites, more ice cores and snow samples must be analyzed in other sectors of Antarctica to check the validity of this figure

  6. 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.)

  7. Estimation of critical loads for radiocaesium in Fennoscandia and Northwest Russia

    International Nuclear Information System (INIS)

    Howard, B.J.; Wright, S.M.; Barnett, C.L.; Skuterud, L.; Strand, P.

    2002-01-01

    The application of the critical loads methodology for radioactive contamination of Arctic and sub-arctic ecosystems, where natural and semi-natural food products are important components of the diet of many people, is proposed and discussed. The critical load is herein defined as the amount of radionuclide deposition necessary to produce radionuclide activity concentrations in food products exceeding intervention limits. The high transfer of radiocaesium to reindeer meat gives this product the lowest critical load, even though the intervention limit is relatively high compared with other products. Ecological half-lives of radiocaesium in natural and semi-natural products are often very long, and it is therefore important to take account of contamination already present in the event of an accident affecting areas where such products are important. In particular, the long ecological half-life for radiocaesium in moose meat means that the critical load is highly sensitive to prior deposition. An example of the potential application of the method for emergency preparedness is given for the Chernobyl accident

  8. Radionuclide-migration model for buried waste at the Savannah River Plant

    International Nuclear Information System (INIS)

    King, C.M.; Root, R.W. Jr.

    1982-01-01

    Solid waste has been buried at the Savannah River Plant burial ground since 1953. The solid waste is contaminated with alpha-emitting transuranium (TRU) nuclides, with beta-gamma-emitting activation and fission products, and with tritium. To provide guidance for the current use and eventual permanent retirement of the burial site from active service, a radionuclide environmental transport model has been used to project the potential influence on man if the burial site were occupied after decommissioning. The model used to simulate nuclide migration includes the various hydrological, animal, vegetative, atmospheric, and terrestrial pathways in estimating dose to man as a function of time. Specific scenarios include a four-person home farm on the 195-acre burial ground. Key input to the model includes site-specific nuclide migration rates through soil, nuclide distribution coefficients, and site topography. Coupled with literature data on plant and animal concentration factors, transfer coefficients reflecting migration routes are input to a set of linear differential equations for subsequent matrix solution. Output from the model is the nuclide-specific decayed curie intake by man. To discern principal migration routes, model-compartment inventories with time can also be displayed. Dose projections subsequently account for organ concentrations in man for the nuclide of interest. Radionuclide migration has been examined in depth with the dose-to-man model. Movement by vegetative pathways is the primary route for potential dose to man for short-lived isotopes. Hydrological routes provide a secondary scheme for long-lived nuclides. Details of model methodology are reviewed

  9. Evaluation of the radionuclide tracer test conducted at the project Gnome Underground Nuclear Test Site, New Mexico

    International Nuclear Information System (INIS)

    Pohll, G.; Pohlmann, K.

    1996-08-01

    A radionuclide tracer test was conducted in 1963 by the U.S. Geological Survey at the Project Gnome underground nuclear test site, approximately 40 km southeast of Carlsbad, New Mexico. The tracer study was carried out under the auspices of the U.S. Atomic Energy Commission (AEC) to study the transport behavior of radionuclides in fractured rock aquifers. The Culebra Dolomite was chosen for the test because it was considered to be a reasonable analogue of the fractured carbonate aquifer at the Nevada Test Site (NTS), the principal location of U.S. underground nuclear tests. Project Gnome was one of a small number of underground nuclear tests conducted by the AEC at sites distant from the NTS. The Gnome device was detonated on December 10, 1961 in an evaporate unit at a depth of 360 m below ground surface. Recently, the U.S. Department of Energy (DOE) implemented an environmental restoration program to characterize, remediate, and close these offsite nuclear test areas. An early step in this process is performance of a preliminary risk analysis of the hazard posed by each site. The Desert Research Institute has performed preliminary hydrologic risk evaluations for the groundwater transport pathway at Gnome. That evaluation included the radioactive tracer test as a possible source because the test introduced radionuclides directly into the Culebra Dolomite, which is the only aquifer at the site. This report presents a preliminary evaluation of the radionuclide tracer test as a source for radionuclide migration in the Culebra Dolomite. The results of this study will assist in planning site characterization activities and refining estimates of the radionuclide source for comprehensive models of groundwater transport st the Gnome site

  10. 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

  11. 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

  12. 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...

  13. Radionuclide transport in a single fissure

    International Nuclear Information System (INIS)

    Eriksen, T.E.

    1984-01-01

    Radionuclide migration has been studied in natural fissures running parallel to the axes of granitic drill cores. A short pulse of radionuclide solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. At the end of each experiment the fissure was opened and the radionuclide distribution on the fissure surfaces measured. The retardation of 241 Am(III) at pH 8.2 as well as the variation in 235 Np(V) retardation with pH are found to be in good agreement with K d-values obtained in batch experiments. The reduction of (TcO - 4 ) to Tc(IV) leads as expected to increasing retardation.(author)

  14. Ingestion Pathway Transfer Factors for Plutonium and Americium

    International Nuclear Information System (INIS)

    Blanchard, A.

    1999-01-01

    Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site

  15. Radionuclide migration in water reservoirs

    International Nuclear Information System (INIS)

    Rodionova, L.F.

    1983-01-01

    Toxicity degree and radiation effect of different radionuclides depend on multiple factors, whose interaction can strengthen or weaken the effects through the mechanism of nuclide accumulation by hydrobiontes. Stage of development of an aquatic organism, its age, mass and sex as well as lifetime and residence time of the organism in the given medium are of importance. The radionuclide build up depends on illumination, locale of the bioobject residence, on the residence nature. The concentration of radionuclides in aquatic organisms and bionts survival depend on a season, temperature of the residence medium, as well as salinity and mineral composition of water influence

  16. Effective equivalent dose in the critical group due to release of radioactive effluents

    International Nuclear Information System (INIS)

    Santos, John W.A. dos; Varandas, Luciana R.; Souza, Denise N.; Souza, Cristiano B.F.; Lima, Sandro Leonardo N.; Mattos, Marcos Fernando M.; Moraes, Jose Adenildo T.

    2005-01-01

    To ensure that the emissions of radioactive material by liquid and gaseous pathways are below applicable limits it is necessary to evaluate the effective equivalent dose in the critical group, which is a magnitude that takes into consideration the modeling used and the terms radioactive activity source. The calculation of this dose considers each radionuclide released by the activity of Nuclear plant, liquid and gaseous by, and the sum of the values obtained is controlled so that this dose does not exceed the goals of the regulatory body, the CNEN and the goals established by the Nuclear power plant. To hit these targets various controls are used such as: controls for effluent monitors instrumentation, environmental monitoring programs, effluent release controls and dose calculation in the environment. According to the findings, it is concluded that during the period of operation of the plants, this dose is below of the required limits

  17. Radionuclide Air Emissions Report for 2012

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, Linnea [Ernest Orlando Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

    2013-05-01

    Berkeley Lab operates facilities where radionuclides are produced, handled, store d, and potentially emitted . These facilities are subject to the EPA radioactive air emission regulations in 40 CFR 61, Subpart H (EPA 1989a). Radionuclides may be emitted from stacks or vents on buildings where radionuclide production or use is authorized or they may be emitted as diffuse sources. In 2012, all Berkeley Lab sources were minor sources of radionuclides (sources resulting in a potential dose of less than 0.1 mrem/yr [0.001 mSv/yr]) . These minor sources include d about 140 stack sources and no diffuse sources . T here were no unplanned airborne radionuclide emissions from Berkeley Lab operations . Emissions from minor sources were measured by sampling or monitoring or were calculated based on quantities used, received for use, or produced during the year. Using measured and calculated emissions, and building- specific and common parameters, Laboratory personnel applied the EPA -approved computer code s, CAP88-PC and COMPLY , to calculate doses to the maximally exposed individual (MEI) at any offsite point where there is a residence, school, business, or office. Because radionuclides are used at three noncontiguous locations (the main site, Berkeley West Bio center, and Joint BioEnergy Institute), three different MEIs were identified.

  18. Radionuclide supply of the progeny via mother's milk

    International Nuclear Information System (INIS)

    Ovcharenko, E.P.

    1982-01-01

    While examining transition of radioactive substances from material organism to milk and then radionuclide administration with milk to progeny, a number of relationships had been revealed. They are similar to those discovered by the author during his study on transplacental radionuclide kinetics. The quantity of transition through placental and milk barriers of group 2 Periodical system radionuclides is inversally proportional to radionuclide mass number. There is evidence for the increase of radionuclide transition per different kinds of animal progeny mass unit during pregnancy as well as during lactation [ru

  19. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 3. Inventory of radionuclides underground at the atolls

    International Nuclear Information System (INIS)

    1998-08-01

    The objective of Working Group 3 was to independently estimate the underground inventories of radionuclides, at the French nuclear test site on the atolls of Mururoa and Fangataufa, and to estimate the distribution of radionuclides between four major components - lava, rubble, gas and water - that determines the mobility of radionuclides in the geosphere. The group also provided a summary of the critical damage dimensions, such as the cavity radius, fissure zone radius and the height of the chimney. As a lot of dimensional data were provided by the French Liaison Office the focus of this report has been to compare these data with experience gained from other test sites in the world

  20. Water, soil, crops and radionuclides. Studies on the behavior of radionuclides in the terrestrial environments

    International Nuclear Information System (INIS)

    Uchida, Shigeo

    2008-01-01

    In order to predict the migration of artificially-produced radionuclides into a human body and its radiation dose rates of human body and to decrease the exposed radiation doses of human body, the behavior of radionuclides in the environment must be elucidated. In National Institute of Radiological Sciences (NIRS), the environmental radioecological research group of Nakaminato Laboratory for Marine Radioecology has progressed the survey and research on the behavior of artificially-produced radionuclides in the terrestrial environment. This article describes the research results (the radioactivity of water, soil, and crops) made so far at Nakaminato Laboratory for Marine Radioecology. (M.H.)

  1. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.

    2013-06-10

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) (CFR 2010a) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan in 2011. NNSA/NFO demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations on the NNSS (U.S. Environmental Protection Agency [EPA] and DOE 1995). This method was approved by the EPA for use on the NNSS in 2001 (EPA 2001a) and has

  2. National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.

    2014-06-04

    The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitations to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) (CFR 2010a) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include radiation unrelated to NNSS activities. Unrelated doses could come from naturally occurring radioactive elements, from sources such as medically or commercially used radionuclides, or from sources outside of the United States, such as the damaged Fukushima nuclear power plant in Japan in 2011. NNSA/NFO demonstrates compliance with the NESHAP limit by using environmental measurements of radionuclide air concentrations at critical receptor locations on the NNSS (U.S. Environmental Protection Agency [EPA] and DOE 1995). This method was approved by the EPA for use on the NNSS in 2001 (EPA 2001a) and has

  3. Identification of cell proliferation, immune response and cell migration as critical pathways in a prognostic signature for HER2+:ERα- breast cancer.

    Directory of Open Access Journals (Sweden)

    Jeffrey C Liu

    Full Text Available Multi-gene prognostic signatures derived from primary tumor biopsies can guide clinicians in designing an appropriate course of treatment. Identifying genes and pathways most essential to a signature performance may facilitate clinical application, provide insights into cancer progression, and uncover potentially new therapeutic targets. We previously developed a 17-gene prognostic signature (HTICS for HER2+:ERα- breast cancer patients, using genes that are differentially expressed in tumor initiating cells (TICs versus non-TICs from MMTV-Her2/neu mammary tumors. Here we probed the pathways and genes that underlie the prognostic power of HTICS.We used Leave-One Out, Data Combination Test, Gene Set Enrichment Analysis (GSEA, Correlation and Substitution analyses together with Receiver Operating Characteristic (ROC and Kaplan-Meier survival analysis to identify critical biological pathways within HTICS. Publically available cohorts with gene expression and clinical outcome were used to assess prognosis. NanoString technology was used to detect gene expression in formalin-fixed paraffin embedded (FFPE tissues.We show that three major biological pathways: cell proliferation, immune response, and cell migration, drive the prognostic power of HTICS, which is further tuned by Homeostatic and Glycan metabolic signalling. A 6-gene minimal Core that retained a significant prognostic power, albeit less than HTICS, also comprised the proliferation/immune/migration pathways. Finally, we developed NanoString probes that could detect expression of HTICS genes and their substitutions in FFPE samples.Our results demonstrate that the prognostic power of a signature is driven by the biological processes it monitors, identify cell proliferation, immune response and cell migration as critical pathways for HER2+:ERα- cancer progression, and defines substitutes and Core genes that should facilitate clinical application of HTICS.

  4. Radionuclides and stable elements in the sediments of the Yesa Reservoir, Central Spanish Pyrenees

    Energy Technology Data Exchange (ETDEWEB)

    Navas, Ana; Gaspar, Leticia; Palazon, Leticia [Estacion Experimental Aula Dei (EEAD- CSIC), Zaragoza (Spain). Dept. of Soil and Water; Valero-Garces, Blas [Instituto Pirenaico de Ecologia (IPE-CSIC), Zaragoza (Spain)

    2011-09-15

    radionuclides, sediment components and stable elements provided evidence of a stronger influence of the dynamics of sediment supply by floods in the central areas closer to the main channel (cores) than in the littoral areas (profile). Conclusions: The radionuclide distributions were consistent with the history of the reservoir infilling and with the processes of transport and accumulation of sediments. Compared to the natural radionuclides, the artificial radionuclide {sup 137}Cs varied the most and showed distinctive patterns. The methods used allowed the identification of natural inputs into the system and its differentiation from fluvial transport and reservoir deposition. The results provide insights into the pathways and processes involved in the mobilization of radionuclides in the environment. (orig.)

  5. Abscess detection with radionuclides

    International Nuclear Information System (INIS)

    Alavi, J.B.

    1988-01-01

    Radionuclide studies may aid in the diagnosis and localization of intra-abdominal infections. Despite the introduction of new radiographic and ultrasound methods, there are several clinical situations in which radionuclide scans have proved useful. Those include detection of postoperative intra-abdominal abscess, evaluation of liver abscess, differentiation between pancreatic pseudocyst or abscess, evaluation of fever of unknown origin, and evaluation of inflammatory bowel disease. Each clinical situation is discussed separately here

  6. 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

  7. Impact of kinetics and flow path heterogeneity on nanoparticle/radionuclide migration

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Florian M.

    2011-11-29

    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

  8. Natural and Synthetic Barriers to Immobilize Radionuclides

    International Nuclear Information System (INIS)

    Um, W.

    2011-01-01

    The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

  9. Therapy for incorporated radionuclides: scope and need

    International Nuclear Information System (INIS)

    Smith, V.H.

    1981-03-01

    In the United States the recent termination of funding for research on therapy for incorporated radionuclides has virtually halted progress on improved or new agents and procedures for removing radioactivity from the body. Research was eliminated, but is still needed on new removal agents, improved delivery system, in vitro test systems, and the toxicology of treatments. For many radionuclides, no adequate therapy exists. The relationship between radionuclide removal and reduction in cancer risk is still unanswered. Without proper research support, needed improvements in the treatment for incorporated radionuclides in the US are uncertain

  10. Mathematical modeling of radionuclide release through a borehole in a radioactive waste repository

    International Nuclear Information System (INIS)

    Choi, Heui Joo

    1996-02-01

    The effects of inadvertent human intrusion as a form of direct drilling into a radioactive waste repository are discussed in this thesis. It has been mentioned that the inadvertent direct drilling into the repository could provide a release pathway for radionuclides even with its low occurrence probability. The following analyses are carried out regarding the problem. The maximum concentration in a water-filled borehole penetrating a repository is computed with a simple geometry. The modeling is based upon the assumption of the diffusive mass transfer in the waste forms and the complete mixing in the borehole. It is shown that the maximum concentrations of six radionuclides in the borehole could exceed the Maximum Permissible Concentration. Also, the diffusive mass transport in a water-filled borehole is investigated with a solubility-limited boundary condition. An analytic solution is derived for this case. Results show that the diffusive mass transport is fast enough to justify the assumption of the complete mixing compared with the considered time span. The axial diffusive mass transport along a water-filled borehole is modeled to compute the release rate taking account of the rock matrix diffusion. The results show that the release of short-lived radionuclides are negligible due to the low concentration gradient in early time and the rock matrix diffusion. The release rates of four long-lived radionuclides are computed. It is also shown that the model developed could be applied to a borehole at a non-cylindrically shaped repository and the off-center drilling of a cylindrical repository. The release rates of long-lived nuclides through a porous material-filled borehole are computed. The results show that the release of all the long-lived nuclides is negligible up to half million years in the case that the borehole is filled with the porous material. The radiological effects of the nuclides released through the borehole penetrating the repository are computed

  11. Effects of radionuclides on non-human biota and natural ecosystem

    International Nuclear Information System (INIS)

    Garnier-Laplace, J.; Adam, C.; Gilbin, R.; Denison, F.; Fortin, C.; Simon, O.

    2004-01-01

    The need for a system of radiological protection of the environment drives regulators to urge scientists on conceptualisation of methods to demonstrate that the environment is protected against radioactive contaminants. One of the major difficulties in the implementation of ecological risk assessment for radioactive pollutants is the lack of data for wildlife chronic internal exposure to alpha or beta emitters. Situations of such chronic internal exposure at low levels are likely to cause toxic responses distinct from those observed after acute exposure at high doses because of the bioaccumulation phenomena. Biochemical mechanisms can lead to a gradual accumulation of elements present at trace level in the external medium, inducing a highly localised deposit within tissues or cells. These highly localised accumulations of radionuclides, coupling radiological and chemical toxicities, particularly for heavy elements such as actinides, may give rise to particular biological responses of a cell group, capable of causing functional or structural abnormalities at higher hierarchical levels. The assessment of these bioaccumulation phenomena investigated within the ENVIRHOM programme launched two years ago at the Institute for Radioprotection and Nuclear Safety, is primordial with regard to internal exposure to radionuclides since they increase locally both the radionuclide concentration and the biological effect of the delivered dose. Gaps of knowledge within this field constitute a strong limitation to our capability to make a reasonable risk estimate. Internal doses cannot be accurately calculated and potentially associated biological effects at any organization level remain fairly unknown. As a result, derivation of ecologically relevant and knowledge-based predicted no-effect concentrations becomes a critical issue in ERA. The scope of this paper is to illustrate the relevance of the development of a greater depth of understanding of radionuclide fate and biological

  12. Phytoremediation of soils contaminated with radionuclides

    International Nuclear Information System (INIS)

    Yamaguchi, Isamu

    2004-01-01

    Aiming at efficient phytoremediation of soils contaminated with radionuclides, we examined the effect of soil microbes on the uptake ability of plants using the multitracer technique to find that tomato rhizofungi in Fusarium spp. can stimulate the uptake of 85 Sr and 137 Cs by the plants. The synergic effect of a nonpathogenic strain of F. oxysporum on the uptake of radionuclides by plants proved to be enhanced by introducing a phytochelatin synthase gene into the fungus. Since soil contamination by radionuclides is still an unsolved problem in many parts of the world. Studies on phytoremediation of polluted soil environment will be important for developing effective strategies and devising adequate techniques to reduce human risks caused by food contamination of radionuclides. (author)

  13. Assessments for high dose radionuclide therapy treatment planning

    International Nuclear Information System (INIS)

    Fisher, D.R.

    2003-01-01

    Advances in the biotechnology of cell specific targeting of cancer and the increased number of clinical trials involving treatment of cancer patients with radiolabelled antibodies, peptides, and similar delivery vehicles have led to an increase in the number of high dose radionuclide therapy procedures. Optimised radionuclide therapy for cancer treatment is based on the concept of absorbed dose to the dose limiting normal organ or tissue. The limiting normal tissue is often the red marrow, but it may sometimes be the lungs, liver, intestinal tract, or kidneys. Appropriate treatment planning requires assessment of radiation dose to several internal organs and tissues, and usually involves biodistribution studies in the patient using a tracer amount of radionuclide bound to the targeting agent and imaged at sequential timepoints using a planar gamma camera. Time-activity curves are developed from the imaging data for the major organ tissues of concern, for the whole body and sometimes for selected tumours. Patient specific factors often require that dose estimates be customised for each patient. In the United States, the Food and Drug Administration regulates the experimental use of investigational new drugs and requires 'reasonable calculation of radiation absorbed dose to the whole body and to critical organs' using the methods prescribed by the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Review of high dose studies shows that some are conducted with minimal dosimetry, that the marrow dose is difficult to establish and is subject to large uncertainties. Despite the general availability of software, internal dosimetry methods often seem to be inconsistent from one clinical centre to another. (author)

  14. National Low-Level Waste Management Program Radionuclide Report Series

    International Nuclear Information System (INIS)

    Rudin, M.J.; Garcia, R.S.

    1992-02-01

    This volume serves as an introduction to the National Low-Level Radioactive Waste Management Program Radionuclide Report Series. This report includes discussions of radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha-emitting transuranics with half-lives greater than five years). Each report includes information regarding radiological and chemical characteristics of specific radionuclides. Information is also included discussing waste streams and waste forms that may contain each radionuclide, and radionuclide behavior in the environment and in the human body. Not all radionuclides commonly found at low-level radioactive waste sites are included in this report. The discussion in this volume explains the rationale of the radionuclide selection process

  15. Biosphere modelling for a deep radioactive waste repository: site-specific consideration of the groundwater-soil pathway

    International Nuclear Information System (INIS)

    Grogan, H.A.; Baeyens, B.; Mueller, H.; Dorp, F. van

    1991-07-01

    Scenario evaluations indicate that groundwater is the most probable pathway for released radionuclides to reach the biosphere from a deep underground nuclear waste repository. This report considers a small valley in northern Switzerland where the transport of groundwater to surface soil might be possible. The hydrological situation has been examined to allow a system of compartments and fluxes for modelling this pathway with respect to the release of radionuclides from an underground repository to be produced. Assuming present day conditions the best estimate surface soil concentrations are calculated by dividing the soil into two layers (deep soil, surface soil) and assuming an annual upward flux of 10 mm from the groundwater through the two soil layers. A constant unit activity concentration is assumed for the radionuclides in the groundwater. It is concluded that the resultant best estimate values must still be considered to be biased on the conservative side, in view of the fact that the more typical situation is likely to be that no groundwater reaches the surface soil. Upper and lower estimates for the surface soil radionuclide concentrations are based on the parameter perturbation results which were carried out for three key parameters, i.e. precipitation surplus, upward flux and solid-liquid distribution coefficients (K d ). It is noted that attention must be given to the functional relationships which exist between various model parameters. Upper estimates for the surface soil concentration are determined assuming a higher annual upward flux (100 mm) as well as a more conservative K d value compared with the base case. This gives rise to surface soil concentrations more than two orders of magnitude higher than the best estimate values. The lower estimated are more easily assigned assuming that no activity reaches the surface soil via this pathway. (author) 18 figs., 4 tabs., refs

  16. Final report on the Pathway Analysis Task

    International Nuclear Information System (INIS)

    Whicker, F.W.; Kirchner, T.B.

    1993-04-01

    The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University's Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere

  17. Final report on the Pathway Analysis Task

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, F.W.; Kirchner, T.B. [Colorado State Univ., Fort Collins, CO (United States)

    1993-04-01

    The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University`s Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere.

  18. Iodine Pathways and Off-Gas Stream Characteristics for Aqueous Reprocessing Plants – A Literature Survey and Assessment

    Energy Technology Data Exchange (ETDEWEB)

    R. T. Jubin; D. M. Strachan; N. R. Soelberg

    2013-09-01

    Used nuclear fuel is currently being reprocessed in only a few countries, notably France, England, Japan, and Russia. The need to control emissions of the gaseous radionuclides to the air during nuclear fuel reprocessing has already been reported for the entire plant. But since the gaseous radionuclides can partition to various different reprocessing off-gas streams, for example, from the head end, dissolver, vessel, cell, and melter, an understanding of each of these streams is critical. These off-gas streams have different flow rates and compositions and could have different gaseous radionuclide control requirements, depending on how the gaseous radionuclides partition. This report reviews the available literature to summarize specific engineering data on the flow rates, forms of the volatile radionuclides in off-gas streams, distributions of these radionuclides in these streams, and temperatures of these streams. This document contains an extensive bibliography of the information contained in the open literature.

  19. Remediation of radionuclide pollutants through biosorption - an overview

    Energy Technology Data Exchange (ETDEWEB)

    Das, Nilanjana [Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore (India)

    2012-01-15

    The development of nuclear science and technology has led to the increase of nuclear wastes containing radionuclides to be released and disposed in the environment. Pollution caused by radionuclides is a serious problem throughout the world. To solve the problem, substantial research efforts have been directed worldwide to adopt sustainable technologies for the treatment of radionuclide containing wastes. Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. A variety of biomaterials viz. algae, fungi, bacteria, plant biomass, etc. have been reported for radionuclide remediation with encouraging results. This paper reviews the achievements and current status of radionuclide remediation through biosorption which will provide insights into this research frontier. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50 MeV

    International Nuclear Information System (INIS)

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

    2016-01-01

    The excitation functions were measured for the "n"a"tCu(α,x)"6"6","6"7Ga,"6"5Zn,"5"7","5"8","6"0Co reactions in the energy range of 16.5 −50 MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications. - Highlights: • New measurements of gallium radionuclides for monitor reactions. • Production of cobalt radionuclides via alpha route on natural Copper. • Extensive critical review of earlier reported cross-sections.

  1. Initial site characterization and evaluation of radionuclide contaminated soil waste burial grounds

    International Nuclear Information System (INIS)

    Phillips, S.J.; Reisenauer, A.E.; Rickard, W.H.; Sandness, G.A.

    1977-02-01

    A survey of historical records and literature containing information on the contents of 300 Area and North Burial Grounds was completed. Existing records of radioactive waste location, type, and quantity within each burial ground facility were obtained and distributed to cooperating investigators. A study was then initiated to evaluate geophysical exploration techniques for mapping buried waste materials, waste containers, and trench boundaries. Results indicate that a combination of ground penetrating radar, magnetometer, metal detector, and acoustic measurements will be effective but will require further study, hardware development, and field testing. Drilling techniques for recovering radionuclide-contaminated materials and sediment cores were developed and tested. Laboratory sediment characterization and fluid transport and monitoring analyses were begun by installation of in situ transducers at the 300 North Burial Ground site. Biological transport mechanisms that control radionuclide movement at contaminated sites were also studied. Flora and fauna presently inhabiting specific burial ground areas were identified and analyzed. Future monitoring of specific mammal populations will permit determination of dose rate and pathways of contaminated materials contained in and adjacent to burial ground sites

  2. Radionuclide injury to the lung

    International Nuclear Information System (INIS)

    Dagle, G.E.; Sanders, C.L.

    1984-01-01

    Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequently observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. 88 references

  3. Analytical sensitivity of Tc99m radionuclide 'milk' scanning in the detection of gastro-oesophageal reflux

    Energy Technology Data Exchange (ETDEWEB)

    Paton, J.Y.; Nanayakkara, C.S.; Cosgriff, P.S.

    1985-09-01

    The analytical sensitivity of radionuclide ''milk'' scans for detecting gastro-oesophageal reflux (GOR) has been assessed using an in vitro simulation test. Five factors were found to affect the ability to detect simulated reflux: isotope concentration, absolute gamma camera sensitivity, absorber thickness overlying the ''oesophagus'' and volume and duration of reflux. We found that a critical volume-duration product must be exceeded for reflux to be detected. Radionuclide milk scanning appears to be much less sensitive in detecting transient events like GOR than might be expected from previously reported static simulation studies.

  4. The vertical distribution of radionuclides in a Ribble Estuary saltmarsh: transport and deposition of radionuclides

    International Nuclear Information System (INIS)

    Brown, J.E.; McDonald, P.; Parker, A.; Rae, J.E.

    1999-01-01

    Routine discharges of low-level liquid radioactive waste by British Nuclear Fuels plc (BNFL) at Sellafield and Springfields have resulted in enhanced levels of radionuclides in sediments of the Ribble Estuary, NW England, UK. Variations in radionuclide concentrations ( 137 Cs, 230 Th, and 239240 Pu) with depth in a mature saltmarsh core were analysed in order to investigate historical discharge trends and waste-dispersal mechanisms. Core samples from Longton/Hutton Marsh were analysed by gamma-spectrometry and α-spectrometry for radionuclides and by laser granulometry to establish grain-size variations with depth. Distinct subsurface maxima were present for 137 Cs and 239240 Pu with activities as high as 4500 Bq kg -1 for 137 Cs and 600 Bq kg -1 for 239240 Pu. Thorium-230 exhibited complex activity profiles with depth, specific activities ranging between 200 and 2400 Bq kg -1 . The vertical distributions of Sellafield-derived radionuclides ( 137 Cs and 239240 Pu) in mature saltmarsh deposits reflect the time-integrated discharge pattern from Sellafield, implying a transport mechanism that has involved the mixing of sediment labelled with radioactivity from recent discharges and sediment labelled from historical discharge events before deposition. A mechanism involving the transport of contaminated silt therefore seems to dominate. The vertical distribution of Springfields-derived 230 Th in the same areas reflects the annual gross-α discharge pattern from BNFL Springfields. In contrast to the Sellafield-derived radionuclides, a fairly rapid transport mechanism from source to sink is implied, with little or no time for mixing with radionuclides discharged years earlier. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Columbia River Pathway Dosimetry Report, 1944-1992

    International Nuclear Information System (INIS)

    Farris, W.T.; Napier, B.A.; Simpson, J.C.; Snyder, S.F.; Shipler, D.B.

    1994-04-01

    The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. One objective of the HEDR Project is to estimate doses to individuals who were exposed to the radionuclides released to the Columbia River (the river pathway). This report documents the last in a series of dose calculations conducted on the Columbia River pathway. The report summarizes the technical approach used to estimate radiation doses to three classes of representative individuals who may have used the Columbia River as a source of drinking water, food, or for recreational or occupational purposes. In addition, the report briefly explains the approaches used to estimate the radioactivity released to the river, the development of the parameters used to model the uptake and movement of radioactive materials in aquatic systems such as the Columbia River, and the method of calculating the Columbia River's transport of radioactive materials. Potential Columbia River doses have been determined for representative individuals since the initiation of site activities in 1944. For this report, dose calculations were performed using conceptual models and computer codes developed for the purpose of estimating doses. All doses were estimated for representative individuals who share similar characteristics with segments of the general population

  6. Evaluation of the anthropogenic radionuclide concentrations in sediments and fauna collected in the Beaufort Sea and northern Alaska

    International Nuclear Information System (INIS)

    Efurd, D.W.; Miller, G.G.; Rokop, D.J.

    1997-07-01

    This study was performed to establish a quality controlled data set about the levels of radio nuclide activity in the environment and in selected biota in the U.S. Arctic. Sediment and biota samples were collected by the National Oceanic and Atmospheric Administration (NOAA), the National Biological Service, and the North Slope Borough's Department of Wildlife Management to determine the impact of anthropogenic radionuclides in the Arctic. The results summarized in this report are derived from samples collected in northwest Alaska with emphasis on species harvested for subsistence in Barrow, Alaska. Samples were analyzed for the anthropogenic radionuclides 90 Sr, 137 Cs, 238 Pu, 239 Pu, 240 Pu and 241 Am. The naturally occurring radionuclides 40 K, 212 Pb and 214 Pb were also measured. One goal of this study was to determine the amounts of anthropogenic radionuclides present in the Beaufort Sea. Sediment samples were isotopically fingerprinted to determine the sources of radio nuclide activities. Biota samples of subsistence and ecological value were analyzed to search for evidence of bio-accumulation of radionuclides and to determine the radiation exposures associated with subsistence living in northern Alaska. The anthropogenic radio nuclide content of sediments collected in the Beaufort Sea was predominantly the result of the deposition of global fallout. No other sources of anthropogenic radionuclides could be conclusively identified in the sediments. The anthropogenic radio nuclide concentrations in fish, birds and mammals were very low. Assuming that ingestion of food is an important pathway leading to human contact with radioactive contaminants and given the dietary patterns in coastal Arctic communities, it can be surmised that marine food chains are presently not significantly affected

  7. Field investigations of the transfer of caesium-137 in the pasture-cow-milk pathway in West Cumbria

    International Nuclear Information System (INIS)

    Sumerling, T.J.

    1983-01-01

    Routine discharges from the nuclear fuel reprocessing installation at Sellafield provide an opportunity to study the behaviour in the environment of several artificially produced radionuclides. Two investigations of the transfer of radionuclides in the pasture-cow-milk pathway are described. The uptake of 137 Cs by cattle grazing sea-washed pasture near Ravenglass has been investigated by in vivo measurements of the animals. A very low coefficient of transfer from feed to meat was estimated. The transfer of several radionuclides, notably 90 Sr, 137 Cs, 239 Pu and 241 Am, is being studied at a dairy farm near Sellafield. Preliminary results for 137 Cs are reported and are found to be in reasonable agreement with model predictions. (author)

  8. Development of an Ingestion Pathway Model for AXAIRQ

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.

    1999-01-13

    AXAIRQ is a dose mode code used for prospective accident assessment at the Savannah River Site and is primarily used to show regulatory compliance. For completeness of pathway analysis, an ingestion model, AXINGST, has been developed for use with, and incorporation in, AXAIRQ. Currently available ingestion models were referenced as a basis for AXINGST. AXINGST calculates a conservative ingestion dose following an atmospheric release of radionuclides and includes site specific variables where applicable.

  9. Interpretation of biological-rate coefficients derived from radionuclide content, radionuclide concentration and specific activity experiments

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.

    1976-01-01

    Rigorous expressions are derived for the biological-rate coefficients (BRCs) determined from time-dependent measurements of three different dependent variables of radionuclide tracer experiments. These variables, which apply to a single organism, are radionuclide content, radionuclide concentration and specific activity. The BRCs derived from these variables have different mathematical expressions and, for high growth rates, their numerical values can be quite different. The precise mathematical expressions for the BRCs are presented here to aid modelers in selecting the correct parameters for their models and to aid experiments in interpreting their results. The usefulness of these three variables in quantifying elemental uptakes and losses by organisms is discussed. (U.K.)

  10. Research on sorption behavior of radionuclides under shallow land environment. Mechanism and standard methodologies for measurement of distribution coefficients of radionuclides

    International Nuclear Information System (INIS)

    Sakamoto, Yoshiaki; Tanaka, Tadao; Takebe, Shinichi; Nagao, Seiya; Ogawa, Hiromichi; Komiya, Tomokazu; Hagiwara, Shigeru

    2001-01-01

    This study consists of two categories' research works. One is research on sorption mechanism of radionuclides with long half-life, which are Technetium-99, TRU elements and U series radionuclides, on soil and rocks, including a development of database of distribution coefficients of radionuclides. The database on the distribution coefficients of radionuclides with information about measurement conditions, such as shaking method, soil characteristics and solution composition, has been already opened to the public (JAERI-DATABASE 20001003). Another study is investigation on a standard methodology of the distribution coefficient of radionuclide on soils, rocks and engineering materials in Japan. (author)

  11. Automated multi-radionuclide separation and analysis with combined detection capability

    Science.gov (United States)

    Plionis, Alexander Asterios

    The radiological dispersal device (RDD) is a weapon of great concern to those agencies responsible for protecting the public from the modern age of terrorism. In order to effectively respond to an RDD event, these agencies need to possess the capability to rapidly identify the radiological agents involved in the incident and assess the uptake of each individual victim. Since medical treatment for internal radiation poisoning is radionuclide-specific, it is critical to identify and quantify the radiological uptake of each individual victim. This dissertation describes the development of automated analytical components that could be used to determine and quantify multiple radionuclides in human urine bioassays. This is accomplished through the use of extraction chromatography that is plumbed in-line with one of a variety of detection instruments. Flow scintillation analysis is used for 90Sr and 210Po determination, flow gamma analysis is used assess 60 Co and 137Cs, and inductively coupled plasma mass spectrometry is used to determine actinides. Detection limits for these analytes were determined for the appropriate technique and related to their implications for health physics.

  12. 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

  13. Radionuclide carrier

    International Nuclear Information System (INIS)

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

    1978-01-01

    A physiologically acceptable particulate radionuclide carrier is described. It comprises a modified anionic starch derivative with 0.1% to 1.5% by weight of a reducing agent and 1 to 20% by weight of anionic substituents

  14. Chapter 13. Radionuclides in medicine

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with problems connected with using of radionuclides in medicine. Methods of treatment with using of radionuclides are reviewed. Chapter consists of next parts: (1) Remotion of thyroid gland; (2) Treatment of cerebrally tumour in nuclear reactor; (3) Artificial heart

  15. Box modelling approach for evaluation of influence of ice transport of radionuclides for doses to man

    International Nuclear Information System (INIS)

    Iospje, M.

    2002-01-01

    Modelling of the ice transport of radionuclides, which is a unique pathway in the Arctic ocean and adjacent sea areas, is limited by necessity to describe complete processes of incorporation of radioactivity into ice and ice sediment. Freezing / melting processes and transport of 'clean' ice can be described with a good accuracy for relatively short time scale on the basis of the present level of modelling, but detailed description of the sediment entrainment into ice based on the Reynolds equations with attention to coagulation processes is limited by low concentration of particles (grease ice cannot be described) and time scale up to 5 . 10 -2 s (1 . 10 -9 y) what is not available for large time scale and ice masses. Adding the radioactivity incorporation into the ice with following description of transport and fate of radionuclides will lead to further increasing of the complexity of the modelling. Therefore, it is necessary to develop an alternative approach for purposes of radiological assessment on the basis of the box modelling to describe the incorporation of radioactivity into ice and ice sediment, transport of radioactivity by ice and incorporation of radioactivity into sea areas through melding processes. It is shown that the ice transport of radionuclides can be a significant factor for some scenarios and radionuclides. The influence of the ice transport increases with increasing K d values for radionuclides. It is necessary to note that the content and structure of the sediment load in ice vary within wide limits, and therefore, sensitivity and uncertainty analysis can improve the possibility to represent model results satisfactorily. (LN)

  16. Naturally occurring radionuclides in food

    International Nuclear Information System (INIS)

    Djujic, I.

    1995-01-01

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

  17. Radionuclide Sensors for Subsurface Water Monitoring. Final report

    International Nuclear Information System (INIS)

    Timothy DeVol

    2006-01-01

    Contamination of the subsurface by radionuclides is a persistent and vexing problem for the Department of Energy. These radionuclides must be measured in field studies and monitored in the long term when they cannot be removed. However, no radionuclide sensors existed for groundwater monitoring prior to this team's research under the EMSP program. Detection of a and b decays from radionuclides in water is difficult due to their short ranges in condensed media

  18. Uptake by plants of radionuclides from FUSRAP waste materials

    International Nuclear Information System (INIS)

    Knight, M.J.

    1983-04-01

    Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables

  19. Uptake by plants of radionuclides from FUSRAP waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Knight, M.J.

    1983-04-01

    Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables.

  20. Determination of natural occurring radionuclides concentrations

    International Nuclear Information System (INIS)

    Stajic, J.; Markovic, V.; Krstic, D.; Nikezic, D.

    2011-01-01

    Tobacco smoke contains certain concentrations of naturally occurring radionuclides from radioactive chains of uranium and thorium - 214 Pb, 214 Bi, 228 Ac, 208 Tl, 226 Ra, 232 Th and 40 K. Inhaling of tobacco smoke leads to internal exposure of man. In order to estimate absorbed dose of irradiation it is necessary to determine concentrations of radionuclides present in the tobacco leaves. In this paper specific activities of naturally occurring radionuclides were measured in tobacco samples from cigarettes which are used in Serbia. [sr

  1. Manual of bioassay procedures for radionuclides

    International Nuclear Information System (INIS)

    Pleskach, S.; Petkau, A.

    1986-06-01

    A monitoring program is described by which atomic radiation workers ar monitored for internal contamination with radionuclides in the workplace. The program involves analytical procedures for measuring alpha, beta and gamma activity in biological specimens, usually urine. Radionuclides are identified by their characteristic radiation using liquid scintillation counting, and alpha, beta and gamma spectrometry. Examples of calculating the minimum detectable activity for specific radionuclides are given and used to derive call-in-criteria in accordance with which the different groups of workers are monitored each month

  2. Radionuclides in ground-level air

    International Nuclear Information System (INIS)

    Sinkko, K.

    1987-01-01

    In the air surveillance programme the concentrations of artificial radionuclides are monitored in the air close to the ground to obtain the necessary basic data for estimating the exposure of the Finnish population to fall-out radionuclides and also to detect atmospheric traces of radioactive materials caused by their use or production. Airborne dust is collected on filters with high-volume air samplers and the concentrations of gamma-emitting radionuclides in the air are evaluated. In the first quarter of 1986 only long-lived cesium, caused by earlier atmospheric nuclear explosions was detected. The concentrations of cesium were very low. In January and March a small amount of short-lived, fresh fission and activation products were also observed

  3. Biological sampling for marine radioactivity monitoring

    International Nuclear Information System (INIS)

    Fowler, S.W.

    1997-01-01

    Strategies and methodologies for using marine organisms to monitor radioactivity in marine waters are presented. When the criteria for monitoring radioactivity is to determine routes of radionuclide transfer to man, the ''critical pathway'' approach is often applied. Alternatively, where information on ambient radionuclide levels and distributions is sought, the approach of selecting marine organisms as ''bioindicators'' of radioactivity is generally used. Whichever approach is applied, a great deal of knowledge is required about the physiology and ecology of the specific organism chosen. In addition, several criteria for qualifying as a bioindicator species are discussed; e.g., it must be a sedentary species which reflects the ambient radionuclide concentration at a given site, sufficiently long-lived to allow long-term temporal sampling, widely distributed to allow spatial comparisons, able to bioconcentrate the radionuclide to a relatively high degree, while showing a simple correlation between radionuclide content in its tissues with that in the surrounding waters. Useful hints on the appropriate species to use and the best way to collect and prepare organisms for radioanalysis are also given. It is concluded that benthic algae and bivalve molluscs generally offer the greatest potential for use as a ''bioindicator'' species in radionuclide biomonitoring programmes. Where knowledge on contribution to radiological dose is required, specific edible marine species should be the organisms of choice; however, both purposes can be served when the edible species chosen through critical pathway analysis is also an excellent bioaccumulator of the radionuclide of interest. (author)

  4. Interception and translocation of radionuclides in major food crops for Koreans

    International Nuclear Information System (INIS)

    Choi, Y. H.; Lim, K. M.; Park, H. G.; Choi, H. J.; Lee, H. S.

    2002-01-01

    In order to investigate the direct plant contamination pathway of 54 Mn, 57 Co, 85 Sr, 103 Ru and 134 Cs in major food crops for Koreans, rice, soybean and radish plants at different growth stages were sprayed with radioactive solutions in a greenhouse. The interception factor and the translocation factor were quantified as the fraction of the total deposition that is initially retained on the aboveground plant surface and the fraction of the total initial plant activity that is contained in the edible part at harvest, respectively. In rice and radish, interception factors increased as plants grew old to harvest. In soybean, however, rapid defoliation in old plants made interception factors decrease with increasing age during the later part of the growth. There was little difference in the interception factor among radionuclides. Translocation factors decreased in the order of 134 Cs ≥> 57 Co > 54 Mn ≥ 85 Sr > 103 Ru in general and varied with radionuclides by factors of 6-4000, depending on application time and plant species. Translocation factors for rice seeds were the highest when radionuclides were applied at the active seed growth stage and those for soybean seeds were the highest following the application at the early pod-filling stage except for 103 Ru. For radish roots, translocation factors were on the whole the highest following the early- growth-stage application. The obtained data can be used for parameter values in food-chain dose assessment models especially for Koreans and many other Asian people

  5. Interception and translocation of radionuclides in major food crops for Koreans

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Y. H.; Lim, K. M.; Park, H. G.; Choi, H. J.; Lee, H. S. [KAERI, Daejon (Korea, Republic of)

    2002-07-01

    In order to investigate the direct plant contamination pathway of {sup 54}Mn, {sup 57}Co, {sup 85}Sr, {sup 103}Ru and {sup 134}Cs in major food crops for Koreans, rice, soybean and radish plants at different growth stages were sprayed with radioactive solutions in a greenhouse. The interception factor and the translocation factor were quantified as the fraction of the total deposition that is initially retained on the aboveground plant surface and the fraction of the total initial plant activity that is contained in the edible part at harvest, respectively. In rice and radish, interception factors increased as plants grew old to harvest. In soybean, however, rapid defoliation in old plants made interception factors decrease with increasing age during the later part of the growth. There was little difference in the interception factor among radionuclides. Translocation factors decreased in the order of {sup 134}Cs {>=}> {sup 57}Co > {sup 54}Mn {>=} {sup 85}Sr >{sup 103}Ru in general and varied with radionuclides by factors of 6-4000, depending on application time and plant species. Translocation factors for rice seeds were the highest when radionuclides were applied at the active seed growth stage and those for soybean seeds were the highest following the application at the early pod-filling stage except for {sup 103}Ru. For radish roots, translocation factors were on the whole the highest following the early- growth-stage application. The obtained data can be used for parameter values in food-chain dose assessment models especially for Koreans and many other Asian people.

  6. Selected radionuclides important to low-level radioactive waste management

    International Nuclear Information System (INIS)

    1996-11-01

    The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237

  7. Selected radionuclides important to low-level radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

  8. Consideration of In-Growth of Radionuclides for Facility Hazard Categorization

    International Nuclear Information System (INIS)

    Mr. Robert E. Miller

    2007-01-01

    This paper addresses issues associated with the effects of daughter product in-growth on the hazard categorization of facilities in accordance with DOE-STD-1027-92, 'Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports'. There is a list of issues that occur when performing facility hazard categorizations at DOE facilities. The first issue is when radionuclides are concentrated outside of their natural decay schemes, and the resulting daughter products exceed the hazard category three threshold quantity values (HC3 TQVs) while their parents do not. The second issue is if a parent nuclide is evaluated for the inhalation pathway, and the daughter product is evaluated using a different pathway and methodology. The third issue is when the parent and daughter are evaluated using the same pathway for exposure, but the daughter is significantly more radiotoxic than the parent. Lastly, when the TQVs were derived for hazard categorization, the methodology used involved a 24 hour exposure period during which, for the sake of simplicity, no consideration was given to decay and the subsequent in-growth of daughter products. Facility hazard categorization is a snapshot in time and does not provide an accurate inventory for long term operations and/or storage

  9. Measurements for modeling radionuclide transfer in the aquatic environment

    International Nuclear Information System (INIS)

    Kahn, B.

    1976-01-01

    Analytical methods for measuring radionuclides in the aquatic environment are discussed for samples of fresh water and seawater, fish and shellfish, biota such as algae, plankton, seaweed, and aquatic plants, and sediment. Consideration is given to radionuclide collection and concentration, sample preservation, radiochemical and instrumental analysis, and quality assurance. Major problems are the very low environmental levels of the radionuclides of interest, simultaneous occurrence of radionuclides in several chemical and physical forms and the numerous factors that affect radionuclide levels in and transfers among media. Some radionuclides of importance in liquid effluents from nuclear power stations are listed, and sources of radiochemical analytical methods are recommended

  10. Radiological dose assessment for bounding accident scenarios at the Critical Experiment Facility, TA-18, Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    1991-09-01

    A computer modeling code, CRIT8, was written to allow prediction of the radiological doses to workers and members of the public resulting from these postulated maximum-effect accidents. The code accounts for the relationships of the initial parent radionuclide inventory at the time of the accident to the growth of radioactive daughter products, and considers the atmospheric conditions at time of release. The code then calculates a dose at chosen receptor locations for the sum of radionuclides produced as a result of the accident. Both criticality and non-criticality accidents are examined

  11. Deep-ocean disposal of high-activity nuclear wastes: a conservative assessment of the seafood critical pathway

    International Nuclear Information System (INIS)

    Baxter, M.S.; Economides, B.

    1984-01-01

    This paper applies conventional 'worst-case' assumptions to modelling the effects of possible future disposal of high-activity wastes in the oceans. It otherwise uses previously published and generally accepted data to assess the possible intakes of the waste nuclides via consumption of seaweeds, molluscs, crustaceans, plankton and fish. Model-predicted intakes for critical groups generally exceed ICRP-recommended limits, with 244 Cm, 241 Am and 137 Cs being the most potentially hazardous nuclides. The various seafood consumption pathways are found to rank, in decreasing order of potential hazard, as seaweeds > molluscs > plankton > fish > crustaceans. (Auth.)

  12. Transfer into the biosphere of radionuclides released from deep storage of radioactive wastes. Bibliographical study

    International Nuclear Information System (INIS)

    Guedon, V.; Siclet, F.

    1995-03-01

    Most countries with civilian nuclear programs today are encountering difficulty in implementing a nuclear waste management policy that is both technically safe in the long term and accepted by the public. To meet both criteria, the solution most generally envisaged is deep storage either of untreated spent nuclear fuel or of highly radioactive wastes resulting from reprocessing. In order to predict the potential impact of such storage on man, one needs to understand the path followed by radionuclides in the geosphere, and later in the biosphere. Given the time scales involved and the critical nature of the elements concerned, it is indispensable to turn to mathematical modeling of the phenomena. This, however, does not preclude the essential need for in-depth knowledge of the phenomena and of the physico-chemical characteristics of radionuclides. This report presents what is hoped to be a complete inventory of the radionuclides contained in ''high level'' wastes (categories B AND C). The elements concerned in studies on deep storage are essentially long-life radionuclides (both actinides and certain fission and activation products). Their physico-chemical characteristics and their behavior in various ecological compartments are examined. Bibliographical data bearing on: solubility (in an oxidizing, reducing medium), distribution factors (water/rock-sediment-soil), concentration and transfer factors (in aquatic and terrestrial mediums), dose conversion factors (in the case of internal and external irradiation), principal paths of exposure for each radionuclide studied, are presented in this report. Initial results from international projects to model what happens to radionuclides in the biosphere are also presented. In general, they are optimistic as to the future, but nonetheless point to a need to improve the conceptual base of the models, to ensure that all major phenomena and processes are taken into consideration and to examine any possible amplification

  13. Accumulation of radionuclides by lichen symbionts

    Energy Technology Data Exchange (ETDEWEB)

    Nifontova, M G; Kulikov, N V [AN SSSR, Sverdlovsk. Inst. Ehkologii Rastenij i Zhivotnykh

    1983-01-01

    The aim of investigation is the quantitative estimation of ability and role of separate symbionts in the accumulation of radionuclides. As investigation volumes, durably cultivated green lichen alga Trebouxia erici and lichen fungi extracted from Cladonia rangiferina, Parmelia caperata and Acarospora fuscata are used. The accumulation of radioactive isotopes with fungi and seaweeds is estimated according to accumulation coefficients (AC) which are the ratio of radiation concentration in plants and agarized medium. Radionuclide content (/sup 90/Sr and /sup 137/Cs) is determined radiometrically. A special series of experiments is done to investigate radionuclide accumulation dependences with lichen seaweed and fungi on light conditions. It is shown that both symbionts of lichen-seaweed and fungus take part in the accumulation of radionuclide from outer medium (atmospheric fall-out and soil). However fungus component constituting the base of structural organization of thallus provides the greater part of radionuclides accumulated by the plant. Along with this the violation of viability of seaweed symbionts particularly in the case of light deficiency brings about the reduction of /sup 137/Cs sorption by seaweeds and tells on the total content of radiocesium in plant thallus.

  14. Targeted Radionuclide Therapy

    Directory of Open Access Journals (Sweden)

    David Cheng

    2011-10-01

    Full Text Available 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.

  15. Targeted Radionuclide Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ersahin, Devrim, E-mail: devrimersahin@yahoo.com; Doddamane, Indukala; Cheng, David [Department of Diagnostic Radiology, School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06520 (United States)

    2011-10-11

    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.

  16. 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)

  17. 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

  18. Radionuclides in house dust

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-04-01

    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 authorising 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, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  19. Targeted radionuclide therapy for solid tumors: An overview

    International Nuclear Information System (INIS)

    De Nardo, Sally J.; De Nardo, Gerald L.

    2006-01-01

    Although radioimmunotherapy (RIT) has been effective in non-Hodgkin's lymphoma (NHL) as a single agent, solid tumors have shown less clinically significant therapeutic response to RIT alone. The clinical impact of RIT or other forms of targeted radionuclide therapy for solid tumors depends on the development of a high therapeutic index (TI) for the tumor vs. normal tissue effect, and the implementation of RIT as part of synergistic combined modality therapy (CMRIT). Preclinical and clinical studies have provided a wealth of information, and new prototypes or paradigms have shed light on future possibilities in many instances. Evidence suggests that combination and sequencing of RIT in CMRIT appropriately can provide effective treatment for many solid tumors. Vascular targets provide RIT enhancement opportunities and nanoparticles may prove to be effective carriers for RIT combined with intracellular drug delivery or alternating magnetic frequency (AMF) induced thermal tumor necrosis. The sequence and timing of combined modality treatments will be of critical importance to achieve synergy for therapy while minimizing toxicity. Fortunately, the radionuclide used for RIT also provides a signal useful for nondestructive quantitation of the influence of sequence and timing of CMRIT on events in animals and patients. This can be readily accomplished clinically using quantitative high-resolution imaging (e.g., positron emission tomography [PET])

  20. Radionuclide accumulation peculiarities demonstrated by vegetable varieties

    International Nuclear Information System (INIS)

    Kruk, A.V.; Goncharenko, G.G.; Kilchevsky, A.V.

    2004-01-01

    This study focused on ecological and genetic aspects of radionuclide accumulation demonstrated by a number of vegetable varieties. The researches resulted in determining the cabbage varieties which were characterised by the minimal level of radionuclide accumulation. It was shown that the above varieties manifested the relation between radionuclide accumulation and morphobiological characteristics such as vegetation period duration and yield criteria. The study specified the genotypes with high ecological stability as regards to radionuclide accumulation: 'Beloruskaya 85' cabbage and 'Dokhodny' tomato showed the best response to Cs 137, while 'Beloruskaya 85', 'Rusinovka', 'Amager 611' cabbage varieties and 'Sprint' tomato showed the minimal level of Sr 90 accumulation. (authors)

  1. 2008 LANL radionuclide air emissions report

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David P.

    2009-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2008. This report meets the reporting requirements established in the regulations.

  2. 2010 LANL radionuclide air emissions report /

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David P.

    2011-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2010. This report meets the reporting requirements established in the regulations.

  3. Preparation of porous materials for radionuclides capture

    International Nuclear Information System (INIS)

    Bajzikova, Anna; Smrcek, Stanislav; Kozempel, Jan; Vlk, Martin; Barta, Jan

    2015-01-01

    Porous materials showing promise for radionuclide capture from water at contaminated sites were prepared. Nanoporous materials (size of pores 1-100 nm) and some polymers are well suited to this purpose owing their affinity for selected radionuclides. Nanoporous metal oxides and silica gel with styrene-divinylbenzene-TODGA-modified surface were prepared, characterized and tested for radionuclide ( 227 Ac, 227 Th, 223 Ra) capture efficiency. (orig.)

  4. Radionuclide Data Centre. Tasks and problems of obtaining the most reliable values of the nuclear physics characteristics of radionuclides and radiation physics parameters of radionuclide sources

    International Nuclear Information System (INIS)

    Chechev, V.P.

    1994-01-01

    Information is provided on the establishment of the Radionuclide Data Centre under the V.G. Khlopin Radium Institute. Its functions and areas of activity are discussed. The paper focuses on the procedure of obtaining the evaluated values of the decay and radiative characteristics of the widely used radionuclides. (author)

  5. Total Inventory of Selected Radionuclides in Old Solvent Tanks S1 Through S22

    International Nuclear Information System (INIS)

    Leyba, J.D.

    2001-01-01

    The total inventory of fourteen radionuclides, three metals, and volatile organic compounds (VOCs) has been calculated for the twenty-two Old Solvent Tanks (OSTs). The inventory calculations are based upon extensive characterization data of the multiple liquid and sludge samples taken from the OSTs. In addition, the total inventory of sixteen actinides (including error) has been calculated. The actinide inventory will be useful for criticality safety considerations

  6. 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

  7. 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

  8. Mathematical Teaching Strategies: Pathways to Critical Thinking and Metacognition

    OpenAIRE

    Su, Hui Fang Huang " Ricci, Frederick A; Mnatsakanian, Mamikon

    2015-01-01

    A teacher that emphasizes reasoning, logic and validity gives their students access to mathematics as an effective way of practicing critical thinking. All students have the ability to enhance and expand their critical thinking when learning mathematics. Students can develop this ability when confronting mathematical problems, identifying possible solutions and evaluating and justifying their reasons for the results, thereby allowing students to become confident critical thinkers. Critical th...

  9. Table of radionuclides (Vol. 4 - A = 133 to 252)

    International Nuclear Information System (INIS)

    Be, M.M.; Chiste, V.; Dulieu, Ch.; Browne, E.; Chechev, V.; Kuzmenko, N.; Kondev, F.G.; Luca, A.; Galan, M.; Pearce, A.; Huang, X.

    2008-01-01

    with this monograph contains the evaluators' comments for each radionuclide in addition to the data tables included in the monograph. The work involved in evaluating nuclear data is on-going and the recommended values are updated on the LNHB web site at http://www.nucleide.org/DDEP_WG/DDEPdata.htm. The publication of further volumes of Monograph 5 is envisaged as and when necessary to add new radionuclide data or re-evaluations in a more permanent format that can be referenced easily. Although other data sets may still be used when evaluating radionuclide activity, use of this common, recommended data set should help to reduce the uncertainties in activity evaluations and lead to more coherent results for comparisons. In order to update the data of the nuclides already present and to add new evaluations, the Laboratoire National Henri Becquerel (LNHB, France) and the Physikalisch-Technische Bundesanstalt (PTB, Germany) established a cooperative agreement; they were then joined by the Idaho National Engineering and Environmental Laboratory (INEEL, USA), the Lawrence Berkeley National Laboratory (LBNL, USA) and the Khlopin Radium Institute (KRI, Russia). This international collaboration is base d on an informal agreement, the initial work of this group was to discuss and to agree on a methodology t o be used in these evaluations. The data and associated uncertainties were evaluated from all available experiments and taking into account theoretical considerations. The main steps for the evaluation of the data and their uncertainties are: - a critical analysis of all available original publications in order to accept or not each value and it s uncertainty reduced to the combined standard uncertainty; - the determination of the best value which is either the weighted or the unweighted average of the retained values, this is decided after examination of the reduced χ 2 value. For a weighted average of discrepant data, each weight is limited to 50 %, and the uncertainty

  10. General program for the advancement of the radionuclide technology

    International Nuclear Information System (INIS)

    1979-12-01

    The 'General Program for the Advancement of the Radionuclide Technology' was elaborated in 1978 by the 'Arbeitsgemeinschaft zur Foerderung der Radionuklidtechnik' (AFR) (Association for the Promotion of Radionuclide Technology). In addition to an inventory of the major applications of radionuclide technology, this General Program includes a comprehensive description of tasks relating to the central topics of raw materials, environment, technology and materials, health and nutrition, scientific developments of radionuclide technology. The 'General Program for the Advancement of the Radionuclide Technology' serves inter alia as a basis of evaluation in opinions on funding applications filed with the Federal Ministry for Research and Technology (BMFT) with respect to the provision of advanced techniques involving radionuclides for industrial application. (orig.) [de

  11. 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...

  12. Geochemistry and radionuclide migration

    International Nuclear Information System (INIS)

    Isherwood, D.

    1978-01-01

    Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

  13. Short description of the BIOS-model, and selection of biosphere parameters to be used in radionuclide transport and dose

    International Nuclear Information System (INIS)

    Jong, E.J. de; Koester, H.W.; Vries, W.J. de.

    1990-02-01

    In the framework of the PACOMA-project (Performance assessment of confinements for medium and alpha waste), initiated by the European Commission, possible future radiation doses, due to contamination of the biosphere by radionuclides originating from radioactive waste disposed in salt-formations, were calculated. In all cases considered radionuclides coming out of the geosphere enter a river. For the biosphere calculations the BIOS-model, developed by the NRPB in England, is used. A short description of the model, as well as of the adjustments made at the RIVM to calculate the total individual and collective doses and the subdoses of different exposure pathways is given. The values of biosphere parameters selected for the model are presented, together with the literature consulted. (author). 17 refs., 3 figs.; 2 tabs

  14. DKPRO: A radionuclide decay and reprocessing code

    International Nuclear Information System (INIS)

    Wootan, D.; Schmittroth, F.A.

    1997-01-01

    The DKPRO code solves the general problem of modeling complex nuclear wastes streams using ORIGEN2 radionuclide production files. There is a continuing need for estimates of Hanford radionuclides. Physical measurements are one basis; calculational estimates, the approach represented here, are another. Given a known nuclear fuel history, it is relatively straightforward to calculate radionuclide inventories with codes such as the widely-used Oak Ridge National Laboratory code ORIGEN2

  15. Assessment of doses due to radionuclides in sewage sludge for different scenario of its use

    International Nuclear Information System (INIS)

    Lydagiene, R.; Morkunas, G.; Pilkyte, L.

    2003-01-01

    Assessment of doses due to radionuclides in sewage sludge for different scenarios of its use was made for sewage plant storage in Visaginas, Rimses district, Karlu village. Calculations of individual and collective doses were made on the basis of results of measurements. Two potential exposure pathways from radionuclides in sewage sludge were considered and two scenarios descriptions were made. The first scenario is when the sludge is using for fertilization, and the second one - the sludge is covered with soil. Using program Environ-Calc made by American Chemical Society the number of samples needed to be sampled was optimized. 38 sewage samples were collected for gamma spectrometrical measurements and 10 samples - for measurements of tritium activity. Results of measurements pointed out that the sludge has no higher activity of tritium that background ones. The only two man made radionuclides 60 Co and 137 Cs were found by gamma spectrometry in the sludge. Average activity for the fresh weight in the samples of 60 Co was 42 Bq/kg, 137 Cs - 10 Bq/kg. Concentration of natural radionuclides was in the same range as in any soil samples from Lithuania. The dose for the first scenario for 1 years child will be 12 μSv, for adult - 9,4 μSv. In another scenario doses for the workers in sewage plant were estimated as 0,76 mSv. Collective dose in case of use of sewage sludge for fertilizers will be 4,4*10 -3 man Sv. The lowest doses will be when the sewage storage is covered using soil. (author)

  16. Transfer of radionuclides into human milk

    International Nuclear Information System (INIS)

    Steiner, M.; Wirth, E.

    1998-01-01

    Up until now the potential radiation exposure to breast-fed babies due to contaminated human milk has not been taken into account, when deriving international limit values and reference levels for radionuclides in foodstuffs, in air at monitored work places or for exposures in the medical field. It was the aim of the research project 'Transfer of radionuclides into human milk' to quantify the transfer of incorporated radionuclides into mother's milk, and develop simple models to estimate the radiation exposure of babies through the ingestion of human milk. The study focused on considerations of the radiation exposure due to the ingestion of contaminated foodstuffs by the mother, the inhalation of radionuclides at monitored work places, and the administration of radiopharmaceuticals to breast-feeding mothers. The blocking of infant thyroid glands by stable iodine in the case of accidental releases of radioiodine was considered as well. (orig.) [de

  17. A cross-study gene set enrichment analysis identifies critical pathways in endometriosis

    Directory of Open Access Journals (Sweden)

    Bai Chunyan

    2009-09-01

    Full Text Available Abstract Background Endometriosis is an enigmatic disease. Gene expression profiling of endometriosis has been used in several studies, but few studies went further to classify subtypes of endometriosis based on expression patterns and to identify possible pathways involved in endometriosis. Some of the observed pathways are more inconsistent between the studies, and these candidate pathways presumably only represent a fraction of the pathways involved in endometriosis. Methods We applied a standardised microarray preprocessing and gene set enrichment analysis to six independent studies, and demonstrated increased concordance between these gene datasets. Results We find 16 up-regulated and 19 down-regulated pathways common in ovarian endometriosis data sets, 22 up-regulated and one down-regulated pathway common in peritoneal endometriosis data sets. Among them, 12 up-regulated and 1 down-regulated were found consistent between ovarian and peritoneal endometriosis. The main canonical pathways identified are related to immunological and inflammatory disease. Early secretory phase has the most over-represented pathways in the three uterine cycle phases. There are no overlapping significant pathways between the dataset from human endometrial endothelial cells and the datasets from ovarian endometriosis which used whole tissues. Conclusion The study of complex diseases through pathway analysis is able to highlight genes weakly connected to the phenotype which may be difficult to detect by using classical univariate statistics. By standardised microarray preprocessing and GSEA, we have increased the concordance in identifying many biological mechanisms involved in endometriosis. The identified gene pathways will shed light on the understanding of endometriosis and promote the development of novel therapies.

  18. Uptake of uranium and thorium series radionuclides by the waterlily, Nymphaea violacea

    International Nuclear Information System (INIS)

    Pettersson, H.B.L.

    1993-01-01

    The waterlily Nymphaea violacea is a major aquatic macrophyte in the waters of the Alligator Rivers Region, Northern Territory, Australia. It is also a traditional Aboriginal diet item, and is considered to be potentially one of the main contributors to the effective dose equivalent arising from consumption of so called bush food in the region. Because of the proximity of the Ranger Uranium Mine (RUM), the activity concentrations of the U and Th series radionuclides have been studied in water, sediment and waterlily during different seasons at five sites downstream of the mine site. The objectives of the study are: 1. To identify the major source of radionuclide uptake by the plant; i.e. water or sediment; 2. To assess the concentration factors/ratios needed for predicting the radiation exposure of the critical group resulting from any discharge of water to the aquatic environment from the Ranger uranium mine; 3. To estimate the natural radiation exposure of the public arising from consumption of waterlilies. (Author)

  19. Radionuclide migration in crystalline rock fractures

    International Nuclear Information System (INIS)

    Hoelttae, P.

    2002-01-01

    Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

  20. The fast multiple-path NUCTRAN model -- Calculating the radionuclide release from a repository

    International Nuclear Information System (INIS)

    Romero, L.; Moreno, L.; Neretnieks, I.

    1995-01-01

    The NUCTRAN model has been applied to the Swedish KBS-3 nuclear waste repository concept, where the migration of radionuclides is through various barriers and pathways. The escape of the nuclides from the canister occurs through a small hole. This hole controls the release of nuclides from the repository. NUCTRAN is a useful tool to calculate the nonstationary transport in a repository for high-level nuclear waste. The advantage of this model is the use of a coarse compartmentalization of the repository, which makes it flexible and easy to adapt to different geometries. The several radionuclide release calculations made with NUCTRAN have shown the capability of this to handle different situations rapidly and easily. The particularity of these calculations is the high accuracy obtained by using a coarse compartmentalization of the Swedish KBS-3 repository and the small requirements of computing time. At short times for short-lived nuclides, the calculated releases are exaggerated. The error can be considerably reduced by an additional subdivision of large compartments into a few compartments

  1. Gastroesophageal reflux in children: radionuclide gastroesophagography

    International Nuclear Information System (INIS)

    Blumhagen, J.D.; Rudd, T.G.; Christie, D.L.

    1980-01-01

    Sixty-five symptomatic infants and children underwent radionuclide gastroesophagography, acid reflux testing, and barium esophagography with water-siphon testing to evaluate the clinical efficacy of the scintigraphic technique in detecting gastroesophageal reflux. After ingesting /sup 99m/Tc sulfur colloid in fruit juice, patients rested beneath the gamma camera for 30 to 60 min while esophageal activity was monitored continuously. By using the acid reflux test as a standard of comparison, the senstivity of radionuclide gastroesophagography was 75%. Because of its physiologic nature, low radiation exposure, and convenience, radionuclide gastroesophagography warrants further evaluation as a screening test for gastroesophageal reflux

  2. Soil - plant experimental radionuclide transfer factors

    International Nuclear Information System (INIS)

    Dobrin, R.I.; Dulama, C.N.; Toma, Al.

    2006-01-01

    Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

  3. The behaviour of long-lived redox sensitive radionuclides in soil-plant system during the process of climate change

    Energy Technology Data Exchange (ETDEWEB)

    Semioshkina, N.; Staudt, C.; Kaiser, C. [Helmhotz Zetrum Muenchen (Germany); Proehl, G. [International Atomic Energy Agency - IAEA (International Atomic Energy Agency (IAEA)); Noseck, U.; Fahrenholz, C. [Gesellschaft fuer Anlagen- und Reaktorsicherheit - GRS (Germany)

    2014-07-01

    One important aspect of climate changes for the long-term safety assessment of radioactive waste repositories is its impact on exposure pathways for humans in the future, which are dependent on the environmental characteristics mentioned. It is conceivable that effects or processes occurring during climate changes lead to an increased accumulation and/or release of radionuclides in the biosphere resulting in higher doses compared to that calculated for discrete climate states. In order to shed light on this question key processes are identified which might lead to such an increased accumulation and/or release of radionuclides. The transition from one climate to another can cause changes in the physicochemical composition of radionuclides: some of them may become more available for plant uptake and due to this, their activity concentration in the plants increases. Other radionuclides maybe stronger bound to soil and their activity concentration in plants decreases. Such changes might also cause remobilization of radionuclides from localised areas with contaminated sediments, their re-suspension and transfer to the surrounding areas. A suitable illustration of the processes related to the changes of the redox potential is the examination of a dry lake or fen bed for agricultural purposes as pasture or ameliorated pasture. In these cases the accumulation of radionuclides in the lake or fen sediment is followed by their release and increasing mobility after agricultural processing of the dry bed of lake or fen. Ploughing of the soil leads to increased supply of oxygen to previous anoxic soil layers causing an increase in redox potential. The presented model describes a scenario, where the land is initially very humid and very low Eh-values cause high sorption and accumulation of radionuclides in soil particles. Then this land is dried out, the redox potential increases and redox sensitive radionuclides change their speciation and their behaviour. Such processes might

  4. Sources of anthropogenic radionuclides in the environment: a review

    International Nuclear Information System (INIS)

    Hu Qinhong; Weng Jianqing; Wang Jinsheng

    2010-01-01

    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 on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides 99 Tc and 129 I, as well as geochemical behavior for radionuclides 99 Tc, 129 I, and 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.

  5. Transuranic radionuclides dispersed into the aquatic environment, a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Stoker, A.C.; Wong, Kai M. [and others

    1994-04-01

    The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. Our intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions (i.e., site specific) in terrestrial, aquatic and atmospheric environments An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of our literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments. On the basis of our reviews, we have arbitrarily outlined five general source terms. These are fallout, fuel cycle waste, accidents, disposal sites and resuspension. Resuspension of the transuranic radionuclides is a unique source term, in that the radionuclides can originate from any of the other source terms. If these transuranic radionuclides become resuspended into the air, they then become important as a source of inhaled radionuclides.

  6. Use of the food-chain model FOOD III and the soil model SCEMR to assess irrigation as a biosphere pathway

    International Nuclear Information System (INIS)

    Sheppard, S.C.

    1985-02-01

    Irrigation of contaminated water onto crop land is a relatively direct pathway for radionuclides to deliver a radiation dose to man. Irrigation was not originally included in the SYVAC assessment model for the Precambrian Shield because no irrigation is currently practised in the region. This report re-evaluates this decision. An analysis of meteorological data shows that crop yield in northern Ontario would benefit from irrigation. Thus, incentives are present for subsistence-scale, and perhaps commercial-scale, irrigation of surface or well water. A food-chain analysis indicated that irrigation with contaminated water could deliver a dose comparable to direct consumption (drinking) of the same water, for some radionuclides. Long-term contamination of soil through irrigation was predicted to be a substantial hazard, even when soil leaching was incorporated into the food-chain model. This report presents parameter estimates that could be used to incorporate irrigation as a pathway in the SYVAC code and will constitute the basis for further decisions concerning this pathway

  7. Parameters used in the environmental pathways (DESCARTES) and radiological dose (CIDER) modules of the Hanford Environmental Dose Reconstruction Integrated Codes (HEDRIC) for the air pathway. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S.F.; Farris, W.T.; Napier, B.A.; Ikenberry, T.A.; Gilbert, R.O.

    1992-09-01

    This letter report is a description of work performed for the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project was established to estimate the radiation doses to individuals resulting from releases of radionuclides from the Hanford Site since 1944. This work is being done by staff at Battelle, Pacific Northwest Laboratories (Battelle) under a contract with the Centers for Disease Control (CDC) with technical direction provided by an independent Technical Steering Panel (TSP). The objective of this report is to-document the environmental accumulation and dose-assessment parameters that will be used to estimate the impacts of past Hanford Site airborne releases. During 1993, dose estimates made by staff at Battelle will be used by the Fred Hutchinson Cancer Research Center as part of the Hanford Thyroid Disease Study (HTDS). This document contains information on parameters that are specific to the airborne release of the radionuclide iodine-131. Future versions of this document will include parameter information pertinent to other pathways and radionuclides.

  8. Parameters used in the environmental pathways and radiological dose modules of the Phase I air pathway code

    International Nuclear Information System (INIS)

    Shindle, S.F.; Ikenberry, T.A.; Napier, B.A.

    1992-05-01

    This report is a description of work performed for the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project was established to estimate radiation doses to individuals resulting from releases of radionuclides from the Hanford Site since 1944, when facilities there first began operating. An independent Technical Steering Panel directs the project, which is conducted by Battelle staff from the Pacific Northwest Laboratory. The objective of Phase 1 of the HEDR Project was to demonstrate through calculation that adequate models and support data existed or could be developed to allow estimation of realistic doses to individuals from historical Hanford Site radionuclide releases. The HEDR Phase 1 computer code was used to model the transport of iodine-131 released to the atmosphere from the Hanford Site facilities, through environmental pathways to points of human exposure. Output from the code was preliminary estimates of doses received by members of the public living in the vicinity of the Hanford Site. Later project work continues to build upon Phase 1 progress in order to refine dose estimates

  9. Development of scheme for predicting atmospheric dispersion of radionuclides during nuclear emergency by using atmospheric dynamic model

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Haruyasu; Chino, Masamichi; Yamazawa, Hiromi (Japan Atomic Energy Research Inst., Tokyo (Japan))

    1999-07-01

    The meteorological forecast models are critically important for the accuracy of predicting the atmospheric dispersion of radionuclides discharged into atmosphere during nuclear emergencies. Thus, this paper describes a new scheme for predicting environmental impacts due to accidental release of radionuclides by using an atmospheric dynamic model PHYSIC. The advantages of introducing PHYSIC are, (1) three-dimensional local meteorological forecasts can be conducted, (2) synoptic meteorological changes can be considered by inputting grid data of synoptic forecasts from Japan Meteorological Agency to PHYSIC as initial and boundary conditions, (3) forecasts can be improved by nudging method using local meteorological observations, and (4) atmospheric dispersion model can consider the variation of the mixed layer. (author)

  10. Development of scheme for predicting atmospheric dispersion of radionuclides during nuclear emergency by using atmospheric dynamic model

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Chino, Masamichi; Yamazawa, Hiromi

    1999-01-01

    The meteorological forecast models are critically important for the accuracy of predicting the atmospheric dispersion of radionuclides discharged into atmosphere during nuclear emergencies. Thus, this paper describes a new scheme for predicting environmental impacts due to accidental release of radionuclides by using an atmospheric dynamic model PHYSIC. The advantages of introducing PHYSIC are, (1) three-dimensional local meteorological forecasts can be conducted, (2) synoptic meteorological changes can be considered by inputting grid data of synoptic forecasts from Japan Meteorological Agency to PHYSIC as initial and boundary conditions, (3) forecasts can be improved by nudging method using local meteorological observations, and (4) atmospheric dispersion model can consider the variation of the mixed layer. (author)

  11. Radionuclide characterization of environmental air around nuclear facilities

    International Nuclear Information System (INIS)

    Gede Sutresna Wijaya; Anung Muharini

    2015-01-01

    Air is an important environmental component in human life. Presence of air pollutants or contaminants will have a negative impact on human health. According to the existence of a nuclear facility in Yogyakarta, the characterization of radionuclides in the air is absolutely necessary to ensure the safety of people and the environment and also to supervise the safe operation of the facility. In this research the characterization of radionuclides in the air was carried through the air sampling by using High Volume Air Sampler equipped with filter TFA 2133, followed by analysis using combination of a gamma and alpha spectrometers. The concentration of radioactivity in the air fluctuates depending on the time and duration of sampling. Characterization of gamma emitting radionuclides in the air is dominated by radon progeny radionuclides such as 214 Pb, 214 Bi with activity 20.09 ± 1.23 until 32.91 ± 4.87 Bq/m 3 and 31.22 ± 1.76 until 44.25 ± 4.91 Bq/m 3 . Alpha emitter radionuclide was dominated by 214 Po (7.69 MeV) which is also radon progeny and a primordial radionuclides. It can be concluded that the presence of radionuclides in the environmental air not as a product resulting from the operation of nuclear facilities in Yogyakarta. (author)

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tamponnet, C. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France)], E-mail: christian.tamponnet@irsn.fr; Martin-Garin, A.; Gonze, M.-A. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France); Parekh, N. [Center for Ecology and Hydrology, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Vallejo, R.; Sauras-Yera, T.; Casadesus, J. [Department of Plant Biology, University of Barcelona, 08028 Barcelona (Spain); Plassard, C.; Staunton, S. [INRA, UMR Rhizosphere and Symbiosis, Place Viala, 34060 Montpellier (France); Norden, M. [Swedish Radiation Protection Institute, 171 16 Stockholm (Sweden); Avila, R. [Facilia AB, Valsgaerdevaegen 12, 168 53 Bromma, Stockholm (Sweden); Shaw, G. [Division of Agricultural and Environmental Sciences University Park, Nottingham NG7 2RD (United Kingdom)

    2008-05-15

    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{sub 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

  14. An approach to the calculation of dose commitment arising from different methods for the long-term management of uranium mill tailings through aquatic pathways

    International Nuclear Information System (INIS)

    1983-01-01

    This report describes the development and use of the aquatic pathway portion of a diagnostic model. The model was developed as part of a study intended to improve methods for estimating the environmental dispersion of radionuclides from uranium mill tailings disposal sites. This, the aquatic portion of the study, investigates radionuclide dispersion through aquatic pathways from a hypothetical mill tailings disposal site and presents dose commitment calculations for human exposure to the simulated patterns of radionuclide concentrations over time. Dose commitment estimates are made, based on the simulated geochemical behaviour of the hypothetical site and tailings, aquatic dispersion from the generic site located in northern Ontario and human exposure to and utilization of aquatic products (fish, water). The dose commitment estimates are presented based upon a range of input variable assumptions. This, the 'Aquatic Technical Appendix', describes all important aspects of: the aquatic portion of the diagnostic model, the modelling of the hypothetical tailings site and tailings mass, and findings resulting from use of the models. This report does not predict real radiation doses, or real radionuclide dispersion patterns for any site whether existing or projected

  15. UFOING: A program for assessing the off-site consequences from ingestion of accidentally released radionuclides

    International Nuclear Information System (INIS)

    Steinhauer, C.

    1988-12-01

    The program UFOING estimates foodchain-related consequences following accidental releases of radionuclides to the atmosphere. It was developed as a stand-alone supplement to the accident consequence assessment program system UFOMOD to allow faster and more detailed investigations of the consequences arising from the foodchain pathways than possible with the version of UFOING which is implemented in UFOMOD. For assumed releases at different times of the year, age dependent individual doses, collective doses, individual risks for fatal stochastic somatic health effects as a function of time, the total numbers of the effects, and the areas affected by foodbans together with the estimated duration of the bans are calculated. In addition, percentage contributions of radionuclides and foodstuffs to the doses and risks can be evaluated. In the first part of this report, an overview over the program is given. The other parts contain a user's guide, a program guide, and descriptions of the data employed and of the version of UFOING which is implemented in UFOMOD. (orig.) [de

  16. A basic toxicity classification of radionuclides

    International Nuclear Information System (INIS)

    1963-01-01

    In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs

  17. A basic toxicity classification of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    1963-04-01

    In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs.

  18. Method of preparing radionuclide doses

    International Nuclear Information System (INIS)

    Kuperus, J.H.

    1987-01-01

    A method is described of preparing aliquot dosea of a tracer material useful in diagnostic nuclear medicine comprising: storing discrete quantities of a lyophilized radionuclide carrier in separate tubular containers from which air and moisture is excluded, selecting from the tubular containers a container in which is stored a carrier appropriate for a nuclear diagnostic test to be performed, interposing the selected container between the needle and the barrel of a hypodermic syringe, and drawing a predetermined amount of a liquid containing a radionuclide tracer in known concentration into the hypodermic syringe barrel through the hypodermic needle and through the selected container to dissolve the discrete quantity of lyophilized carrier therein to combine the carrier with the radionuclide tracer to form an aliquot dose of nuclear diagnostic tracer material, as needed

  19. Sensitivity analysis on a dose-calculation model for the terrestrial food-chain pathway

    International Nuclear Information System (INIS)

    Abdel-Aal, M.M.

    1994-01-01

    Parameter uncertainty and sensitivity were applied to the U.S. Regulatory Commission's (NRC) Regulatory Guide 1.109 (1977) models for calculating the ingestion dose via a terrestrial food-chain pathway in order to assess the transport of chronically released, low-level effluents from light-water reactors. In the analysis, we used the generation of latin hypercube samples (LHS) and employed a constrained sampling scheme. The generation of these samples is based on information supplied to the LHS program for variables or parameters. The actually sampled values are used to form vectors of variables that are commonly used as inputs to computer models for the purpose of sensitivity and uncertainty analysis. Regulatory models consider the concentrations of radionuclides that are deposited on plant tissues or lead to root uptake of nuclides initially deposited on soil. We also consider concentrations in milk and beef as a consequence of grazing on contaminated pasture or ingestion of contaminated feed by dairy and beef cattle. The radionuclides Sr-90 and Cs-137 were selected for evaluation. The most sensitive input parameters for the model were the ground-dispersion parameter, release rates of radionuclides, and soil-to-plant transfer coefficients of radionuclides. (Author)

  20. 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.)

  1. Understanding pathways of exposure using site-specific habits surveys, particularly new pathways and methodologies

    International Nuclear Information System (INIS)

    Grzechnik, M.; McTaggart, K.; Clyne, F.

    2006-01-01

    Full text of publication follows: UK policy on the control of radiation exposure via routine discharges from nuclear licensed sites has long been based on ICRP recommendations that embody the principles of justification of practices, optimisation of protection, and dose limitation. Radiological protection of the public is based on the concept of a critical group of individuals. This group is defined as those people who, as a result of the area they reside and their habits, receive the highest radiation dose due to the operations of a site. Therefore, if the dose to this critical group is acceptable in relation to relevant dose limits and constraints, then other members of the public will receive lower doses. Thus, the principle of critical groups provides overall protection for the public. Surveys to determine local habits involve an integrated methodology, whereby the potential radioactive exposure pathways from liquid and gaseous discharges and direct radiation from the site are investigated. Surveys to identify these habits must be undertaken rigorously for consistency, and have been known to reveal unexpected pathways of radiation exposure. Pathways typically include consumption of local foodstuffs and external exposure. Furthermore, a number of critical groups ma y be identified within a single survey area if the habits of one group do not adequately describe those of the other inhabitants of the area. Survey preparation involves the initial identification of high producers and consumers of local foods in a geographically defined area surrounding the nuclear facility. Pathways can be broken down into three general groups, which include exposure arising from; 1) Terrestrial (gaseous) discharges surveyed within 5 km of the site 2) Direct radiation surveyed within 1 km of the site 3) Aquatic (liquid) discharges surveyed within local areas affected by the discharges, including seas, rivers and sewage works. The survey fieldwork involves interviewing members of the

  2. Predicting soil-to-plant transfer of radionuclides with a mechanistic model (BioRUR)

    Energy Technology Data Exchange (ETDEWEB)

    Casadesus, J. [Servei de Camps Experimentals, Universitat de Barcelona, Avda Diagonal 645, 08028 Barcelona (Spain); Sauras-Yera, T. [Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal 645, 08028 Barcelona (Spain)], E-mail: msauras@ub.edu; Vallejo, V.R. [Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avda Diagonal 645, 08028 Barcelona (Spain); Centro de Estudios Ambientales del Mediterraneo, Charles Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain)

    2008-05-15

    BioRUR model has been developed for the simulation of radionuclide (RN) transfer through physical and biological compartments, based on the available information on the transfer of their nutrient analogues. The model assumes that radionuclides are transferred from soil to plant through the same pathways as their nutrient analogues, where K and Ca are the analogues of Cs and Sr, respectively. Basically, the transfer of radionuclide between two compartments is calculated as the transfer of nutrient multiplied by the ratio of concentrations of RN to nutrient, corrected by a selectivity coefficient. Hydroponic experiments showed the validity of this assumption for root uptake of Cs and Sr and reported a selectivity coefficient around 1.0 for both. However, the application of this approach to soil-to-plant transfer raises some questions on which are the effective concentrations of RN and nutrient detected by the plant uptake mechanism. This paper describes the evaluation of two configurations of BioRUR, one which simplifies the soil as an homogeneous pool, and the other which considers that some concentration gradients develop around roots and therefore ion concentrations at the root surface are different from those of the bulk soil. The results show a good fit between the observed Sr transfer and the mechanistic simulations, even when a homogeneous soil is considered. On the other hand, Cs transfer is overestimated by two orders of magnitude if the development of a decreasing K profile around roots is not taken into account.

  3. Predicting soil-to-plant transfer of radionuclides with a mechanistic model (BioRUR)

    International Nuclear Information System (INIS)

    Casadesus, J.; Sauras-Yera, T.; Vallejo, V.R.

    2008-01-01

    BioRUR model has been developed for the simulation of radionuclide (RN) transfer through physical and biological compartments, based on the available information on the transfer of their nutrient analogues. The model assumes that radionuclides are transferred from soil to plant through the same pathways as their nutrient analogues, where K and Ca are the analogues of Cs and Sr, respectively. Basically, the transfer of radionuclide between two compartments is calculated as the transfer of nutrient multiplied by the ratio of concentrations of RN to nutrient, corrected by a selectivity coefficient. Hydroponic experiments showed the validity of this assumption for root uptake of Cs and Sr and reported a selectivity coefficient around 1.0 for both. However, the application of this approach to soil-to-plant transfer raises some questions on which are the effective concentrations of RN and nutrient detected by the plant uptake mechanism. This paper describes the evaluation of two configurations of BioRUR, one which simplifies the soil as an homogeneous pool, and the other which considers that some concentration gradients develop around roots and therefore ion concentrations at the root surface are different from those of the bulk soil. The results show a good fit between the observed Sr transfer and the mechanistic simulations, even when a homogeneous soil is considered. On the other hand, Cs transfer is overestimated by two orders of magnitude if the development of a decreasing K profile around roots is not taken into account

  4. Production of medical short-lived radionuclides in Canada

    International Nuclear Information System (INIS)

    Wiebe, L.I.

    1985-01-01

    The production of radionuclides for medical and biomedical research in Canada has been reviewed with respect to the national geographic and demographic characteristics which influence their use. The types of facilities available for the production of short-lived radionuclides have been summarized, and a tabulation of the radionuclides that are produced has been presented. In broad terms production facilities can be classified as belonging to one of two groups, nuclear reactor or charged-particle accelerators. The charged-particle accelerators produce the more neutron-deficient and (because of the resultant decay properties) the more useful radionuclides for medical application. The nuclear reactor facilities for radionuclide production range in size and capacity from the high-flux research reactors of AECL to the six SLOWPOKE reactors, five of which are located on university campuses across the country. The McMaster University reactor is used to produce curie quantities of fluorine-18 weekly. Millicurie amounts of a large number of radionuclides, most of which have half-lives ranging from 2 to 50 hr, are produced in the low-flux reactors, in support of basic medical research

  5. Simulation of radionuclide transport in U.S. agriculture

    International Nuclear Information System (INIS)

    Sharp, R.D.; Baes, C.F. III.

    1982-01-01

    Because of the recent concern about the impact of energy technologies on man and related health effects, there has emerged a need for models to calculate or predict the effects of radionuclides on man. A general overview is presented of a model that calculates the ingrowth of radionuclides into man's food chain. The FORTRAN IV computer program TERRA, Transport of Environmentally Released Radionuclides in Agriculture, simulates the build-up of radionuclides in soil, four plant food compartments, in meat and milk from beef, and in the livestock food compartments that cause radionuclide build-up in milk and meat from beef. A large data set of spatially oriented parameters has been developed in conjunction with TERRA. This direct-access data set is called SITE, Specific Information on the Terrestrial Environment, and contains 35 parameters for each of 3525 half-degree longitude-latitude cells which define the lower 48 states. TERRA and SITE are used together as a package for determining radionuclide concentrations in man's food anywhere within the conterminous 48 states due to atmospheric releases

  6. 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

  7. Analysis of structure-tectonic pattern within the 'Degelen' massif conformably to conditions of radionuclide migration in ground water

    International Nuclear Information System (INIS)

    Gorbunova, Eh.M.; Ivanchenko, G.N.; Godunova, L.D.

    2005-01-01

    Major orientation of radiation monitoring on the Semipalatinsk test site lies in direction of common regularities for formation and distribution of radioactive contamination. Zones, within the 'Degelen' technical area. of hydrogeological active faults are patly subjected to impact of underground explosions. Data of computer-aided decryption of a stellite image by means of program package LESSA allow specification of para-genesis structures standing as probabilistic pathways of radionuclide migration. (author)

  8. Simulation of radionuclides migration in porous media through integral transform method

    International Nuclear Information System (INIS)

    Ostwald, P.N.; Cotta, R.M.

    1992-01-01

    An analytical solution is obtained for the transient one-dimensional convection-diffusion equation that governs the dispersion of radionuclides through planar porous media, by applying the generalized integral transform technique. The present simulation has direct application in the analysis of radioactive waste migration through the soil and engineering barriers, originated from leakages in waste repositories. Results for concentration distributions in a typical application (Cs 137 ) are critically compared to those from a purely numerical approach, available in a scientific subroutines library. Different runs for combinations of the governing parameters are then interpreted. (author)

  9. Effect of microorganisms on the uptake of radionuclides by plant, application of the plant-microorganism complex system to the phytoremediation

    International Nuclear Information System (INIS)

    Soshi, Takayuki; Enomoto, Shuichi; Yamaguchi, Isamu

    2003-01-01

    Effects of the microorganisms to the uptake of radionuclides by host plant of endophyte (Neotyphodium lolii) to perennial ryegrass, rice pathogenic fungi Gibberella fujikuroi to rice, Fusarium species that is symbiotic to tomato was monitored using the multitracer technique. Perennial ryegrass colonized by endophyte showed lower uptake rate rather than the plant without endophyte. Gibberella fujikuroi was able to increase the uptake of radionuclides (Cs, Sr, Mn, Zn and Co) by rice via infection. Uptake rate of Mn and Co by infected rice plant was elevated to almost two times as that of non-infected plant. The effect of five nonpathogenic strains of F. oxysporum, F. spio rycopersici (N.P.F.) isolated from tomato rhizosphere was analyzed. Each strain shows uptake enhancement of some radionuclide by plant. At least one strain shows critical enhancement of the uptake of Sr and Cs both. (author)

  10. 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

  11. Columbia River pathway report

    International Nuclear Information System (INIS)

    1991-07-01

    This report summarizes the river-pathway portion of the first phase of the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project is estimating radiation doses that could have been received by the public from the Department of Energy's Hanford Site, in southeastern Washington State. Phase 1 of the river-pathway dose reconstruction effort sought to determine whether dose estimates could be calculated for populations in the area from above the Hanford Site at Priest Rapids Dam to below the site at McNary Dam from January 1964 to December 1966. Of the potential sources of radionuclides from the river, fish consumption was the most important. Doses from drinking water were lower at Pasco than at Richland and lower at Kennewick than at Pasco. The median values of preliminary dose estimates calculated by HEDR are similar to independent, previously published estimates of average doses to Richland residents. Later phases of the HEDR Project will address dose estimates for periods other than 1964--1966 and for populations downstream of McNary Dam. 17 refs., 19 figs., 1 tab

  12. 21 CFR 892.1390 - Radionuclide rebreathing system.

    Science.gov (United States)

    2010-04-01

    ... gaseous or volatile radionuclide or a radionuclide-labeled aerosol and permit it to be respired by the patient during nuclear medicine ventilatory tests (testing process of exchange between the lungs and the...

  13. Naturally occurring radionuclides in agricultural products: An overview

    International Nuclear Information System (INIS)

    Hanlon, E.A.

    1994-01-01

    Low levels of naturally occurring radionuclides exist in phosphatic clays, a by-product of phosphatic mining and beneficiation processes. Concerns about these radionuclides entering the human food chain were an immediate research priority before the phosphate clays could be reclaimed for intensive agricultural purposes. Efforts included the assembly of a large body of data from both sons and plants, part of which were produced by the Polk County (Florida) Mined Lands Agricultural Research/Demonstration Project MLAR/DP. Additional detailed studies involving dairy and beef cattle (Bos taurus) were conducted by researchers working with the MLAR/DP. A national symposium was conducted in which data concerning the MLAR/DP work and other research projects also dealing with naturally occurring radionuclides in agriculture could be discussed. The symposium included invited review papers dealing with the identification of radionuclide geological origins, the geochemistry and movement of radionuclides within the environment, mechanisms of plant uptake, entry points into the food chain, and evaluation of dose and risk assessment to the consumer of low levels of radionuclides. The risk to human health of an individual obtaining 0.1 of his or her dietary intake from crops produced on phosphatic clays increased by 1 in 5 x 10 6 /yr above a control individual consuming no food grown on phosphatic clays. Leaf tissues were found to be generally higher than fruit, grain, or root tissues. The natural range in radionuclide content among various food types was greater than the difference in radionuclides content between the same food produced on phosphatic clays vs. natural soils. 19 refs

  14. Migration of radionuclides through a river system

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-03-01

    Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

  15. Health risk due to radionuclides in medicinal plants Western Ghats of Karnataka

    International Nuclear Information System (INIS)

    Laveena, K.B.; Chandra, M.; Kaliprasad, C.S.; Narayana, Y.

    2018-01-01

    Medicinal plants are unique type of natural product requiring special consideration due to their potential impact on human health. The pharmacological properties of the medicinal plants have been attributed to the presence of active chemical constituents which are responsible for important physiological function in living organisms. According to the International Food Safety Authorities Network, plants used as food commonly have 40 K, 232 Th and 238 U and their progenies. It is expected that similarities would be found in plants used for medicinal purposes since plants are the primary pathway of natural radionuclides entering into the human body through the food chain. In many developing countries, pollution is the main causes for the contamination of vegetation with heavy metals, pesticides, or radioactivity. Therefore the medical properties and effectiveness of medicinal plants depend on environmental conditions, which also have a direct influence on their growth in the place of their occurrence and cultivation. So the objective of my study is to study the concentration of radionuclides present in selected medicinal plants and to assess the radiological risk associated with the use of these medicinal plants which has great significance

  16. 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

  17. Online estimation of radionuclide transportation in water environment

    International Nuclear Information System (INIS)

    Yi-Jing Zhang; Li-Sheng Hu

    2017-01-01

    Transportation evaluation of the radionuclide waste discharged from nuclear power plants is an essential licensing issue, especially for inland sites. Basically, the dynamics of radionuclide transportation are nonlinear and time-varying. Motivated by its time-consuming computation, the work proposed an online estimation method for the radionuclide waste in water surface. After extracting the nonlinearity of factors influencing radionuclide transportation, the method utilizes transfer function and generalized autoregressive conditional heteroskedasticity models to perform deterministic and probabilistic estimations. It turns out that, the resulting predictions show high accuracy and can optimize the online discharge management of radioactive waste for nuclear power plants. (author)

  18. Radionuclide examinations

    International Nuclear Information System (INIS)

    Lentle, B.C.

    1989-01-01

    This paper reports on radionuclide examinations of the pancreas. The pancreas, situated retroperitonally high in the epigastrium, was a particularly difficult organ to image noninvasively before ultrasonography and computed tomography (CT) became available. Indeed the organ still remains difficult to examine in some patients, a fact reflected in the variety of methods available to evaluate pancreatic morphology. It is something of a paradox that the pancreas is metabolically active and physiologically important but that its examination by radionuclide methods has virtually ceased to have any role in day-to-day clinical practice. To some extent this is caused by the tendency of the pancreas's commonest gross diseases emdash carcinoma and pancreatitis, for example emdash to result in nonfunction of the entire organ. Disorders of pancreatic endocrine function have generally not required imaging methods for diagnosis, although an understanding of diabetes mellitus and its nosology has been advanced by radioimmunoassay of plasma insulin concentrations

  19. 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)

  20. 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

  1. Migration of radionuclides in geologic media: Fundamental research needs

    International Nuclear Information System (INIS)

    Reed, D.T.; Zachara, J.M.; Wildung, R.E.; Wobber, F.J.

    1990-01-01

    An assessment of the fundamental research needs in understanding and predicting the migration of radionuclides in the subsurface is provided. Emphasis is on the following three technical areas: (1) aqueous speciation of radionuclides, (2) the interaction of radionuclides with substrates, and (3) intermediate-scale interaction studies. This research relates to important issues associated with environmental restoration and remediation of DOE sites contaminated with mixed radionuclide-organic wastes. 64 refs., 1 fig., 1 tab

  2. Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

    CERN Document Server

    Welch, Michael J

    2013-01-01

    Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

  3. Radionuclides incorporation in activated natural nanotubes

    International Nuclear Information System (INIS)

    Silva, Jose Parra

    2016-01-01

    Natural palygorskite nanotubes show suitable physical and chemical properties and characteristics to be use as potential nanosorbent and immobilization matrix for the concentration and solidification of radionuclides present in nuclear wastes. In the development process of materials with sorption properties for the incorporation and subsequent immobilization of radionuclides, the most important steps are related with the generation of active sites simultaneously to the increase of the specific surface area and suitable heat treatment to producing the structural folding. This study evaluated the determining parameters and conditions for the activation process of the natural palygorskite nanotubes aiming at the sorption of radionuclides in the nanotubes structure and subsequent evaluation of the parameters involve in the structural folding by heat treatments. The optimized results about the maximum sorption capacity of nickel in activated natural nanotubes show that these structures are apt and suitable for incorporation of radionuclides similar to nickel. By this study is verified that the optimization of the acid activation process is fundamental to improve the sorption capacities for specifics radionuclides by activated natural nanotubes. Acid activation condition optimized maintaining structural integrity was able to remove around 33.3 wt.% of magnesium cations, equivalent to 6.30·10 -4 g·mol -1 , increasing in 42.8% the specific surface area and incorporating the same molar concentration of nickel present in the liquid radioactive waste at 80 min. (author)

  4. 100 Years of radionuclide metrology

    International Nuclear Information System (INIS)

    Judge, S.M.; Arnold, D.; Chauvenet, B.; Collé, R.; De Felice, P.; García-Toraño, E.; Wätjen, U.

    2014-01-01

    The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics. - Highlights: • The driving forces for the development of radionuclide metrology. • Radium standards to facilitate trade of this valuable commodity in the early years. • After 1950, focus changes to healthcare and industrial applications. • National Measurement Institutes develop new techniques, standards, and disseminate the best practice in measurement. • Challenges in nuclear medicine, radioactive waste management and nuclear forensics

  5. Underground radionuclide migration at the Nevada Test Site

    International Nuclear Information System (INIS)

    Nimz, G.J.; Thompson, J.L.

    1992-01-01

    This document reviews results from a number of studies concerning underground migration of radionuclides from nuclear test cavities at the Nevada Test Site (NTS). Discussed are all cases known to the Department of Energy's Hydrology and Radionuclide Migration Program where radionuclides have been detected outside of the immediate vicinity of nuclear test cavities that are identifiable as the-source of the nuclides, as well as cases where radionuclides might have been expected and were intentionally sought but not fixed. There are nine locations where source-identifiable radionuclide migration has been detected, one where migration was purposely induced by pumping, and three where migration might be expected but was not found. In five of the nine cases of non-induced migration, the inferred migration mechanism is prompt fracture injection during detonation. In the other four cases, the inferred migration mechanism is water movement. In only a few of the reviewed cases can the actual migration mechanism be stated with confidence, and the attempt has been made to indicate the level of confidence for each case. References are cited where more information may be obtained. As an aid to future study, this document concludes with a brief discussion of the aspects of radionuclide migration that, as the present review indicates, are not yet understood. A course of action is suggested that would produce a better understanding of the phenomenon of radionuclide migration

  6. Milk distribution and feeding practice data for the PATHWAY model

    International Nuclear Information System (INIS)

    Ward, G.M.; Whicker, F.W.

    1990-01-01

    Milk is a major source for ingestion of several radionuclides, particularly when it is produced from fresh forage. Estimation of radionuclide ingestion via milk from Nevada Test Site fallout events in the 1950s required information on the sources of milk, feeding practices for cows, and elapsed time between milking and consumption for various geographic areas. These data were essential input to the food-chain model, PATHWAY. A data base was compiled from personal interviews. Milk sources included private cows, local dairies, and regional plants that collected from and distributed to wide geographic areas. Estimates of the contribution of each source were made for communities in a nine-state area. Pasture seasons varied from 3 to 6 mo. Pasture use varied from zero to 80% of the cows' diet. Pasture use declined during the 1950s, as did the number of family cows and local dairy plants. Regional distributors captured a larger portion of the market, and improved technologies increased the shelf life of milk. These factors tended to reduce the human intake of fallout radionuclides from milk in the latter part of the 1950s

  7. 21 CFR 892.5700 - Remote controlled radionuclide applicator system.

    Science.gov (United States)

    2010-04-01

    ... radionuclide applicator system. (a) Identification. A remote controlled radionuclide applicator system is an... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Remote controlled radionuclide applicator system... include patient and equipment supports, component parts, treatment planning computer programs, and...

  8. Critical importance of the de novo pyrimidine biosynthesis pathway for Trypanosoma cruzi growth in the mammalian host cell cytoplasm

    International Nuclear Information System (INIS)

    Hashimoto, Muneaki; Morales, Jorge; Fukai, Yoshihisa; Suzuki, Shigeo; Takamiya, Shinzaburo; Tsubouchi, Akiko; Inoue, Syou; Inoue, Masayuki; Kita, Kiyoshi; Harada, Shigeharu; Tanaka, Akiko; Aoki, Takashi; Nara, Takeshi

    2012-01-01

    Highlights: ► We established Trypanosoma cruzi lacking the gene for carbamoyl phosphate synthetase II. ► Disruption of the cpsII gene significantly reduced the growth of epimastigotes. ► In particular, the CPSII-null mutant severely retarded intracellular growth. ► The de novo pyrimidine pathway is critical for the parasite growth in the host cell. -- Abstract: The intracellular parasitic protist Trypanosoma cruzi is the causative agent of Chagas disease in Latin America. In general, pyrimidine nucleotides are supplied by both de novo biosynthesis and salvage pathways. While epimastigotes—an insect form—possess both activities, amastigotes—an intracellular replicating form of T. cruzi—are unable to mediate the uptake of pyrimidine. However, the requirement of de novo pyrimidine biosynthesis for parasite growth and survival has not yet been elucidated. Carbamoyl-phosphate synthetase II (CPSII) is the first and rate-limiting enzyme of the de novo biosynthetic pathway, and increased CPSII activity is associated with the rapid proliferation of tumor cells. In the present study, we showed that disruption of the T. cruzicpsII gene significantly reduced parasite growth. In particular, the growth of amastigotes lacking the cpsII gene was severely suppressed. Thus, the de novo pyrimidine pathway is important for proliferation of T. cruzi in the host cell cytoplasm and represents a promising target for chemotherapy against Chagas disease.

  9. The contamination of the oceans by anthropogenic radionuclides

    International Nuclear Information System (INIS)

    Figueira, Rubens C.L.; Cunha, Ieda I.L.

    1998-01-01

    Several hundreds of artificial of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxity, longh half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical, dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organism, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radioclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured

  10. Radionuclide examination in rheumatology

    International Nuclear Information System (INIS)

    Streda, A.; Kolar, J.; Valesova, M.

    1984-01-01

    On the basis of twenty years of experience with the use of radionuclides in bone and articular rheumatic diseases indications for such examinations are summed up. The main advantage of the use of radionuclide methods is that they bring forward early diagnosis of tissue reconstruction which can thus be detected at the stage of microstructural changes. They also provide earlier and more reliable detection of the degree of the pathological process than is provided by X-ray examination. In some cases scintiscan may also be found useful as a method for following up the results of treatment of rheumatic diseases. (author)

  11. Solubility limited radionuclide transport through geologic media

    International Nuclear Information System (INIS)

    Muraoka, Susumu; Iwamoto, Fumio; Pigford, T.H.

    1980-11-01

    Prior analyses for the migration of radionuclides neglect solubility limits of resolved radionuclide in geologic media. But actually some of the actinides may appear in chemical forms of very low solubility. In the present report we have proposed the migration model with no decay parents in which concentration of radionuclide is limited in concentration of solubility in ground water. In addition, the analytical solutions of the space-time-dependent concentration are presented in the case of step release, band release and exponential release. (author)

  12. Interactions of radionuclides with marine biota

    International Nuclear Information System (INIS)

    Small, L.F.

    1997-01-01

    Uptake of radioactivity by marine biota can occur through consumption of radioactive food or via direct incorporation from the seawater. As uptake occurs, radioactivity begins to distribute into and onto various body tissues, or ''compartments'', at different rates. A composite uptake curve therefore is curvilinear with time. Elimination can occur via various pathways, including fecal deposition, molting, and excretion of dissolved substances, and therefore a composite loss curve also is curvilinear. Uptake and elimination can occur simultaneously, and under constant conditions over a long time period a steady-state body burden will be achieved. Many factors can affect uptake and loss rates, as well as steady-state body burdens, and some major ones are discussed. Design of radioactivity experiments involving marine biota is explored, and a case study of a ''natural experiment'' involving both reactor-produced and fallout radionuclides in a coastal environment is presented to show how much nuclide introductions can be used to learn about nuclide biomagnification, trophic level relationships, and biological distribution of radioactivity in the sea. (author)

  13. Radionuclide determination of right and left ventricular stroke volumes

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wei Feng; Roubin, G S; Choong, C Y.P.; Harris, P J; Flether, P J; Kelly, D T; Uren, R F; Hutton, B F

    1985-03-01

    The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P < 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

  14. 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

  15. Research progess on treatment of cancer with targeted radionuclide therapy

    International Nuclear Information System (INIS)

    Luo Jiawen; Zhang Caixia

    2008-01-01

    The new development and situation of targeted radionuclide therapy in oncology is described, which include radioimmunotherapy, peptide receptor radionuclide therapy, gene therapy and radionuclide labled chemotherapeutics therapy. The application research on labled carrier of those therapy is emphasized. Meanwhile, the research progess of indomethacin and its combined with targeted radionuclide therapy is also described. (authors)

  16. Radionuclide cisternographic findings in patients with spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Jung, Dong Jin; Kim, Jae Seung; Ryu, Jin Sook; Shin, Jung Woo; Im, Joo Hyuk; Lee, Myoung Chong; Jung, Sung Joo; Moon, Dae Hyuk; Lee, Hee Kyung

    1998-01-01

    Radionuclide cisternography may be helpful in understanding pathophysiology of postural headache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternogrpahic findings of spontaneous intracranial hypotension. The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 1/2 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30 min (6/10) and 2 hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. The characteristics findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration

  17. Fire fighting in a radionuclide laboratory

    International Nuclear Information System (INIS)

    Wenzel, H.

    1991-01-01

    A fire-brigade was called to a laboratory which held a handling licence for the radionuclides C-14, T, P-32, Se-75, Mo-99, and S-35. The fire-brigade was unaware of a release of radionuclides. Therefore they used respiratory equipment, and all persons present were subsequently examined for contamination. (DG) [de

  18. Derived release limits for radionuclides in airborne and liquid effluents for the Whiteshell Nuclear Research Establishment and errata

    International Nuclear Information System (INIS)

    Lemire, A.E.

    1989-08-01

    Radionuclides released to the environment may cause external and internal radiation exposure to man via a number of potential pathways. The resulting radiation dose due to such releases from any operating facility must be kept below dose limits specified in the regulations issued by the Atomic Energy Control Board of Canada. At the Whiteshell Nuclear Research Establishment (WNRE), there is one primary source of liquid effluent to the Winnipeg River via the process water outfall. There are five sources of gaseous effluents: the WR-1 stack; the incinerator stack in the waste management area; the active laboratories building (including the hot cells); the Active-Liquid Waste Treatment Centre; and the compactor-baler in the Waste Management Area. This report presents the methodology and models used to calculate the maximum permissible release rates of radionuclides for each of these sources

  19. Permissible annual depositions and radionuclide concentrations in air

    International Nuclear Information System (INIS)

    Belyaev, V.A.; Golovko, M.Yu.

    1993-01-01

    It is established that it necessary to take into account the other ways of radionuclide intake apart from the inhalation one when determining the standards for radionuclide contamination of the atmospheric air. Whereby it is proposed to standardize annual depositions rather than permissible concentration in the atmospheric air for the ways related to radionuclide releases on the ground surface, which is explained by ambiguity of their dry deposition rate from the air. Formulae and results of calculation of standard characteristics are presented. The permissible radionuclide depositions, related to the intake through food chains are calculated with account for diet diversity, agroclimatic and phenological parameters in different regions of the country

  20. Radionuclide transport in a single fissure

    International Nuclear Information System (INIS)

    Eriksen, T.E.

    1988-12-01

    The study of radionuclide migration through rock is currently of great interest due to its relevance to the possible escape paths into the biosphere of radionuclides released from high level radioactive wastes burried in deep geological repositories. While water will provide the vehicle for transportation, interaction with geological material may greatly influence the radionuclide movement relative that of water. A flow system for laboratory studies of radionuclide transport in natural fissures in granitic rock under reducing conditions is described. The system based on the use of synthetic ground water equilibrated with granitic rock in a well sealed system, allow experiments to be carried out at -240 mV reduction potential. In flow experiments with technetium the retardation was found to be dependent on the method used for reducing TcO 4 - . The preparation of the tracer solutions is crucial, as some of the redox-reactions may be very slow. The dynamics of the Tc(VII) reduction and also speciation need to be carried out in separate experiments. (4 illustrations, 5 tables)