WorldWideScience

Sample records for unexpected atmospheric release

  1. Atmospheric dispersion models of radioactivity releases

    International Nuclear Information System (INIS)

    Oza, R.B.

    2016-01-01

    In view of the rapid industrialization in recent time, atmospheric dispersion models have become indispensible 'tools' to ensure that the effects of releases are well within the acceptable limits set by the regulatory authority. In the case of radioactive releases from the nuclear facility, though negligible in quantity and many a times not even measurable, it is required to demonstrate the compliance of these releases to the regulatory limits set by the regulatory authority by carrying out radiological impact assessment. During routine operations of nuclear facility, the releases are so low that environmental impact is usually assessed with the help of atmospheric dispersion models as it is difficult to distinguish negligible contribution of nuclear facility to relatively high natural background radiation. The accidental releases from nuclear facility, though with negligible probability of occurrence, cannot be ruled out. In such cases, the atmospheric dispersion models are of great help to emergency planners for deciding the intervention actions to minimize the consequences in public domain and also to workout strategies for the management of situation. In case of accidental conditions, the atmospheric dispersion models are also utilized for the estimation of probable quantities of radionuclides which might have got released to the atmosphere. Thus, atmospheric dispersion models are an essential tool for nuclear facility during routine operation as well as in the case of accidental conditions

  2. Unexpectedly high catch-and-release rates in European marine recreational fisheries: implications for science and management

    DEFF Research Database (Denmark)

    Ferter, Keno; Weltersbach, Marc Simon; Strehlow, Harry Vincent

    2013-01-01

    Unexpectedly high catch-and-release rates in European marine recreational fisheries: implications for science and management. – ICES Journal of Marine Science, 70: .While catch-and-release (C&R) is a well-known practice in several European freshwater recreational fisheries, studies on the magnitu...

  3. Atmospheric release advisory capability

    International Nuclear Information System (INIS)

    Sullivan, T.J.

    1981-01-01

    The ARAC system (Atmospheric Release Advisory Capability) is described. The system is a collection of people, computers, computer models, topographic data and meteorological input data that together permits a calculation of, in a quasi-predictive sense, where effluent from an accident will migrate through the atmosphere, where it will be deposited on the ground, and what instantaneous and integrated dose an exposed individual would receive

  4. Unexpected consequences of control: competitive vs. predator release in a four-species assemblage of invasive mammals.

    Science.gov (United States)

    Ruscoe, Wendy A; Ramsey, David S L; Pech, Roger P; Sweetapple, Peter J; Yockney, Ivor; Barron, Mandy C; Perry, Mike; Nugent, Graham; Carran, Roger; Warne, Rodney; Brausch, Chris; Duncan, Richard P

    2011-10-01

    Invasive species are frequently the target of eradication or control programmes to mitigate their impacts. However, manipulating single species in isolation can lead to unexpected consequences for other species, with outcomes such as mesopredator release demonstrated both theoretically and empirically in vertebrate assemblages with at least two trophic levels. Less is known about the consequences of species removal in more complex assemblages where a greater number of interacting invaders increases the potential for selective species removal to result in unexpected changes in community structure. Using a replicated Before-After Control-Impact field experiment with a four-species assemblage of invasive mammals we show that species interactions in the community are dominated by competition rather than predation. There was no measurable response of two mesopredators (rats and mice) following control of the top predator (stoats), but there was competitive release of rats following removal of a herbivore (possums), and competitive release of mice following removal of rats. © 2011 Blackwell Publishing Ltd/CNRS.

  5. Atmospheric Release Advisory Capability

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Gudiksen, P.H.; Sullivan, T.J.

    1983-02-01

    The Atmospheric Release Advisory Capability (ARAC) project is a Department of Energy (DOE) sponsored real-time emergency response service available for use by both federal and state agencies in case of a potential or actual atmospheric release of nuclear material. The project, initiated in 1972, is currently evolving from the research and development phase to full operation. Plans are underway to expand the existing capability to continuous operation by 1984 and to establish a National ARAC Center (NARAC) by 1988. This report describes the ARAC system, its utilization during the past two years, and plans for its expansion during the next five to six years. An integral part of this expansion is due to a very important and crucial effort sponsored by the Defense Nuclear Agency to extend the ARAC service to approximately 45 Department of Defense (DOD) sites throughout the continental US over the next three years

  6. SRNL EMERGENCY RESPONSE CAPABILITY FOR ATMOSPHERIC CONTAMINANT RELEASES

    International Nuclear Information System (INIS)

    Koffman, L; Chuck Hunter, C; Robert Buckley, R; Robert Addis, R

    2006-01-01

    Emergency response to an atmospheric release of chemical or radiological contamination is enhanced when plume predictions, field measurements, and real-time weather information are integrated into a geospatial framework. The Weather Information and Display (WIND) System at Savannah River National Laboratory (SRNL) utilizes such an integrated framework. The rapid availability of predictions from a suite of atmospheric transport models within this geospatial framework has proven to be of great value to decision makers during an emergency involving an atmospheric contaminant release

  7. The Atmospheric Release Advisory Capability Site Workstation System

    International Nuclear Information System (INIS)

    Foster, K.T.; Sumikawa, D.A.; Foster, C.S.; Baskett, R.L.

    1993-01-01

    The Atmospheric Release Advisory Capability (ARAC) is a centralized emergency response service that assesses the consequences that may result from an atmospheric release of toxic material. ARAC was developed by the Lawrence Livermore National Laboratory (LLNL) for the Departments of Energy (DOE) and Defense (DOD) and responds principally to radiological accidents. ARAC provides radiological health and safety guidance to decision makers in the form of computer-generated estimates of the effects of an actual, or potential release of radioactive material into the atmosphere. Upon receipt of the release scenario, the ARAC assessment staff extracts meteorological, topographic, and geographic data from resident world-wide databases for use in complex, three-dimensional transport and diffusion models. These dispersion models generate air concentration (or dose) and ground deposition contour plots showing estimates of the contamination patterns produced as the toxic material is carried by the prevailing winds. To facilitate the ARAC response to a release from specific DOE and DOD sites and to provide these sites with a local emergency response tool, a remote Site Workstation System (SWS) is being placed at various ARAC-supported facilities across the country.. This SWS replaces the existing antiquated ARAC Site System now installed at many of these sites. The new system gives users access to complex atmospheric dispersion models that may be run either by the ARAC staff at LLNL, or (in a later phase of the system) by site personnel using the computational resources of the SWS. Supporting this primary function are a variety of SWS-resident supplemental capabilities that include meteorological data acquisition, manipulation of release-specific databases, computer-based communications, and the use of a simpler Gaussian trajectory puff model that is based on Environmental Protection Agency's INPUFF code

  8. Operators guide: Atmospheric Release Advisory Capability (ARAC) site facility

    International Nuclear Information System (INIS)

    Lawver, B.S.

    1977-01-01

    In this report capabilities and services are described for the Atmospheric Release Advisory Capability (ARAC). The ARAC site system and its operating procedures and interactions with the ARAC central facility located at LLL is outlined. ARAC is designed to help officials at designated ERDA sites and other locations in estimating the effects of atmospheric releases of radionuclides or other hazardous materials by issuing real-time advisories to guide them in their planning

  9. Operators guide: Atmospheric Release Advisory Capability (ARAC) site facility

    International Nuclear Information System (INIS)

    Cassaro, E.; Lomonaco, L.

    1979-01-01

    The Atmospheric Release Advisory Capability (ARAC) is designed to help officials at designated DOE sites and other locations in estimating the effects of atmospheric releases of radionuclides or other hazardous materials by issuing real-time advisories to guide them in their planning. This report outlines the capabilities and sources of ARAC, and in more detail describes an ARAC Site Facility, its operating procedures and interactions with the ARAC Central Facility (ACF) located at LLL

  10. Atmospheric Release Advisory Capability (ARAC)

    International Nuclear Information System (INIS)

    Dickerson, M.H.

    1975-01-01

    The chief purpose of ARAC data acquisition program is to provide site officials, who are responsible for ensuring maximum health protection for the endangered site personnel and public, with estimates of the effects of atmospheric releases of hazardous material as rapidly and accurately as possible. ARAC is in the initial stages of being implemented and is therefore susceptible to changes before it reaches its final form. However the concept of ARAC is fully developed and was successfully demonstrated during a feasibility study conducted in June 1974, as a joint effort between the Savannah River Laboratory (SRL) and Lawrence Livermore Laboratory (LLL). Additional tests between SRL and LLL are scheduled for December 1975. While the immediate goal is the application of ARAC to assist a limited number of ERDA sites, the system is designed with sufficient flexibility to permit expanding the service to a large number of sites. Success in ARAC application should provide nuclear facilities with a means to handle better the urgent questions concerning the potential accidental hazards from atmospheric releases in addition to providing the sites with a capability to assess the effort of their normal operations

  11. Atmospheric dispersion of radionuclides released by a nuclear plant

    International Nuclear Information System (INIS)

    Barboza, A.A.

    1989-01-01

    A numerical model has been developed to simulate the atmospheric dispersion of radionuclides released by a nuclear plant operating under normal conditions. The model, based on gaussian plume representation, accouts for and evaluates several factors which affect the concentraction of effluents in the atmosphere, such as: ressuspension, deposition, radioactive decay, energy and type of the radiation emitted, among others. The concentraction of effluents in the atmosphere is calculated for a uniform mesh of points around the plant, allowing the equivalent doses to be then evaluated. Simulations of the atmosphere dispersion of radioactive plumes of Cs 137 and Ar 41 have been performed assuming a constant rate of release, as expected from the normal operation of a nuclear plant. Finally, this work analyzes the equivalent doses at ground level due to the dispersion of Cs 137 and Ar 41 , accumulated over one year and determines the isodose curves for a hypothetical site. (author) [pt

  12. Atmospheric Dispersion Assessment for Potential Accidental Releases at Yonggwang Nuclear Power Plants

    International Nuclear Information System (INIS)

    Na, Man Gyun; Sim, Young Rok; Jung, Chul Kee; Lee, Goung Jin; Kim, Soong Pyung; Chung, Sung Tai

    2000-01-01

    XOQ DW code is currently used to assess the atmospheric dispersion for the routine releases of radioactive gaseous effluents at Yonggwang nuclear power plants. This code was developed based on XOQDOQ code and an additional code is required to assess the atmospheric dispersion for potential accidental releases. In order to assess the atmospheric dispersion for the accidental releases, XOQAR code has been developed by using PAVAN code that is based on Reg. Guide 1.145. The terrain data of XOQ DW code inputs and the relative concentrations (X/Q) of XOQ DW code outputs are used as the inputs of the XOQAR code through the interface with XOQ DW code. By using this code, the maximum values of X/Q at exclusion area and low population zone boundaries except for sea areas were assessed as 1.33 x 10 -4 and 7.66 x 10 -6 sec/m 3 , respectively. Through the development of this code, a code system is prepared for assessing the atmospheric dispersion for the accidental releases as well as the routine releases. This developed code can be used for other domestic nuclear power plants by modifying the terrain input data

  13. Measured tritium in groundwater related to atmospheric releases from the Marcoule nuclear site

    International Nuclear Information System (INIS)

    Levy, F.; Clech, A.; Crochet, P.

    1996-01-01

    Tritium is released into the atmosphere during normal operation from the industrial facilities operated by COGEMA at Marcoule; over a 1 5-year period covered by this study (1979-1994) the quantities ranged from 4940 to 520 TBq·yr -1 . Atmospheric release in rainy weather results in tritium migration into the ground water by a series of mechanisms associated with the water cycle. COGEMA monitors the ground water by means of bore holes. Atmospheric monitoring is also routinely performed; data on the tritium activity concentration in the air and rainwater are available for the same time period. A simplified observation suggests a relation between the atmospheric tritium release and the ground water radioactivity. In 1994, the activity ranged from 100 to 200 Bq·l -1 in the boreholes located 1 km and 2 km downwind from the point of release, diminishing with the distance to less than 20 Bq·l -1 at about 3 km. The authors attempted to model two types of transfers: atmospheric transfer from the release chimney to the borehole, and transfer in the alluvial ground water. The aquifer comprises the alluvial deposits forming the Codolet plain extending to the south of Marcoule, downwind from the point of atmospheric tritium release. The hydrogeology of the entire Marcoule site has been described in previous studies by the French bureau of geological and mineralogical research (BRGM) and ANTEA. (author)

  14. PAVAN, Atmospheric Dispersion of Radioactive Releases from Nuclear Power Plants

    International Nuclear Information System (INIS)

    2001-01-01

    1 - Description of program or function: PAVAN estimates down-wind ground-level air concentrations for potential accidental releases of radioactive material from nuclear facilities. Options can account for variation in the location of release points, additional plume dispersion due to building wakes, plume meander under low wind speed conditions, and adjustments to consider non-straight trajectories. It computes an effective plume height using the physical release height which can be reduced by inputted terrain features. 2 - Method of solution: Using joint frequency distributions of wind direction and wind speed by atmospheric stability, the program provides relative air concentration (X/Q) values as functions of direction for various time periods at the exclusion area boundary (EAB) and the outer boundary of the low population zone (LPZ). Calculations of X/Q values can be made for assumed ground-level releases or evaluated releases from free-standing stacks. The X/Q calculations are based on the theory that material released to the atmosphere will be normally distributed (Gaussian) about the plume centerline. A straight-line trajectory is assumed between the point of release and all distances for which X/Q values are calculated. 3 - Restrictions on the complexity of the problem: - The code cannot handle multiple emission sources

  15. Evaluation of radioxenon releases in Australia using atmospheric dispersion modelling tools

    International Nuclear Information System (INIS)

    Tinker, Rick; Orr, Blake; Grzechnik, Marcus; Hoffmann, Emmy; Saey, Paul; Solomon, Stephen

    2010-01-01

    The origin of a series of atmospheric radioxenon events detected at the Comprehensive Test Ban Treaty Organisation (CTBTO) International Monitoring System site in Melbourne, Australia, between November 2008 and February 2009 was investigated. Backward tracking analyses indicated that the events were consistent with releases associated with hot commission testing of the Australian Nuclear Science Technology Organisation (ANSTO) radiopharmaceutical production facility in Sydney, Australia. Forward dispersion analyses were used to estimate release magnitudes and transport times. The estimated 133 Xe release magnitude of the largest event (between 0.2 and 34 TBq over a 2 d window), was in close agreement with the stack emission releases estimated by the facility for this time period (between 0.5 and 2 TBq). Modelling of irradiation conditions and theoretical radioxenon emission rates were undertaken and provided further evidence that the Melbourne detections originated from this radiopharmaceutical production facility. These findings do not have public health implications. This is the first comprehensive study of atmospheric radioxenon measurements and releases in Australia.

  16. National Atmospheric Release Advisory Center (NARAC) Capabilities for Homeland Security

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, G; Nasstrom, J; Baskett, R; Simpson, M

    2010-03-08

    The Department of Energy's National Atmospheric Release Advisory Center (NARAC) provides critical information during hazardous airborne releases as part of an integrated national preparedness and response strategy. Located at Lawrence Livermore National Laboratory, NARAC provides 24/7 tools and expert services to map the spread of hazardous material accidentally or intentionally released into the atmosphere. NARAC graphical products show affected areas and populations, potential casualties, and health effect or protective action guideline levels. LLNL experts produce quality-assured analyses based on field data to assist decision makers and responders. NARAC staff and collaborators conduct research and development into new science, tools, capabilities, and technologies in strategically important areas related to airborne transport and fate modeling and emergency response. This paper provides a brief overview of some of NARAC's activities, capabilities, and research and development.

  17. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) with Enhanced Trimming, Release 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains the latest official release of International Comprehensive Ocean-Atmosphere Data Set (ICOADS) with Enhanced Trimming, provided in a common...

  18. CRRIS, Health Risk Assessment from Atmospheric Releases of Radionuclides

    International Nuclear Information System (INIS)

    1999-01-01

    1 - Description of program or function: CRRIS consists of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may be used alone for various assessment applications. Because of its modular structure, CRRIS allows assessments to be tailored to the user's needs. Radionuclides are handled by CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that build up during environmental transport. Atmospheric dispersion calculations are performed by the ANEMOS computer code for distances less than 100 km and the RETADD-II computer code regional-scale distances. Both codes estimate annual-average air concentrations and ground deposition rates by location. SUMIT will translate and scale multiple ANEMOS runs onto a master grid. TERRA reads radionuclide air concentrations and deposition rates to estimate concentrations of radionuclides in food and surface soil. Radiologic decay and ingrowth, soil leaching, and transport through the food chain are included in the calculations. MLSOIL computes an effective radionuclide ground-surface concentration to be used in computing external health effects. The five-layer model of radionuclide transport through soil in MLSOIL provides an alternative to the single-layer model used in TERRA. DFSOIL computes dose factors used in MLSOIL to compute doses from the five soil layers and from the ground surface. ANDROS reads environmental concentrations of radionuclides computed by the other CRRIS codes and produces tables of doses and risks to individuals or populations from atmospheric releases of radionuclides. 2 - Method of solution: SUMIT performs geometric interpolation. TERRA and MLSOIL are terrestrial transport compartment models. DFSOIL computes soil-layer-specific dose factors based on the point-kernel method

  19. The release code package REVOLS/RENONS for fission product release from a liquid sodium pool into an inert gas atmosphere

    International Nuclear Information System (INIS)

    Starflinger, J.; Scholtyssek, W.; Unger, H.

    1994-12-01

    For aerosol source term considerations in the field of nuclear safety, the investigation of the release of volatile and non-volatile species from liquid surfaces into a gas atmosphere is important. In case of a hypothetical liquid metal fast breeder reactor accident with tank failure, primary coolant sodium with suspended or solved fuel particles and fission products may be released into the containment. The computer code package REVOLS/RENONS, based on a theoretical mechanistic model with a modular structure, has been developed for the prediction of sodium release as well as volatile and non-volatile radionuclide release from a liquid pool surface into the inert gas atmosphere of the inner containment. Hereby the release of sodium and volatile fission products, like cesium and sodium iodide, is calculated using a theoretical model in a mass transfer coefficient formulation. This model has been transposed into the code version REVOLS.MOD1.1, which is discussed here. It enables parameter analysis under highly variable user-defined boundary conditions. Whereas the evaporative release of the volatile components is governed by diffusive and convective transport processes, the release of the non-volatile ones may be governed by mechanical processes which lead to droplet entrainment from the wavy pool surface under conditions of natural or forced convection into the atmosphere. The mechanistic model calculates the liquid entrainment rate of the non-volatile species, like the fission product strontium oxide and the fuel (uranium dioxide) from a liquid pool surface into a parallel gas flow. The mechanistic model has been transposed into the computer code package REVOLS/RENONS, which is discussed here. Hereby the module REVOLS (RElease of VOLatile Species) calculates the evaporative release of the volatile species, while the module RENONS (RElease of NON-Volatile Species) computes the entrainment release of the non-volatile radionuclides. (orig./HP) [de

  20. Manual of dose evaluation from atmospheric releases

    Energy Technology Data Exchange (ETDEWEB)

    Shirvaikar, V V; Abrol, V [Health Physics Division, Bhabha Atomic Research Centre, Bombay (India)

    1978-07-01

    The problem of dose evaluation from atmospheric releases is reduced to simple arithmetic by giving tables of concentrations and time integrated concentrations for instantaneous plumes and long time (1 year), sector averaged plumes for distances upto 10 km, effective release heights of upto 200 m and the six Pasquill stability classes. Correction factors for decay, depletion due to deposition and rainout are also given. Inhalation doses, immersion doses and contamination levels can be obtained from these by using multiplicative factors tabulated for various isotopes of significance. Tables of external gamma doses from plume are given separately for various gamma energies. Tables are also given to evaluate external beta and gamma dose rates from contaminated surfaces. The manual also discusses the basic diffusion model relevant to the problem. (author)

  1. The atmospheric release advisory capability (ARAC): A federal emergency response capability

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Sullivan, T.J.

    1988-03-01

    The Atmospheric Release Capability (ARAC) is a Department of Energy (DOE)-sponsored emergency-response service set up to provide real-time prediction of the dose levels and the extent of surface contamination resulting from a broad range of possible occurrences (accidents, spills, extortion threats involving nuclear material, reentry of nuclear-powered satellites, and atmospheric nuclear tests) that could involve the release of airborne radioactive material. During the past decade, ARAC has responded to more than 150 real-time situations, including exercises. The most notable responses include the Three Mile Island accident in Pennsylvania, the Titan II missile accident in Arkansas, the reentry of the USSR's COSMOS-954 into the atmosphere over Canada, the accidental release of uranium hexafluoride from the Sequoyah Facility accident in Oklahoma, and, most recently, the Chernobyl reactor accident in the Soviet Union. ARAC currently supports the emergency-preparedness plans at 50 Department of Defense (DOD) and DOE sites within the US and also responds to accidents that happen elsewhere. Our ARAC center serves as the focal point for data acquisition, data analysis and assessments during a response, using a computer-based communication network to acquire real-time weather data from the accident site and the surrounding region, as well as pertinent accident information. Its three-dimensional computer models for atmospheric dispersion, MATHEW and ADPIC, digest all this information and produce the predictions used in accident assessment. 9 refs., 6 figs., 1 tab

  2. Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

    Science.gov (United States)

    Isaksen, Ivar S.A.; Gauss, Michael; Myhre, Gunnar; Walter Anthony, Katey M.; Ruppel, Carolyn

    2011-01-01

    The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in the atmosphere. Here we apply a “state of the art” atmospheric chemistry transport model to show that large emissions of CH4 would likely have an unexpectedly large impact on the chemical composition of the atmosphere and on radiative forcing (RF). The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO2 as a result of atmospheric chemical processes. Despite uncertainties in emission scenarios, our results provide a better understanding of the feedbacks in the atmospheric chemistry that would amplify climate warming.

  3. The estimation of areas of ground that may be contaminated after an accidental release of pollutant to the atmosphere

    International Nuclear Information System (INIS)

    Corbett, J.O.

    1979-01-01

    A method is developed for calculating the area of ground contaminated above a prescribed level after an accidental release of radioactivity or any other pollutant to the atmosphere. Numerical calculations are made for a wide range of releases, atmospheric conditions and rates of wet and dry deposition. It is shown that high atmospheric stability and rain both tend to maximize the area of significant contamination for most of the plausible range of releases. However, for very large hypothetical releases, dry conditions with an unstable atmosphere spread significant contamination furthest afield. (author)

  4. Static and mobile networks design for atmospheric accidental releases monitoring

    International Nuclear Information System (INIS)

    Abida, R.

    2010-01-01

    The global context of my PhD thesis work is the optimization of air pollution monitoring networks, but more specifically it concerns the monitoring of accidental releases of radionuclides in air. The optimization problem of air quality measuring networks has been addresses in the literature. However, it has not been addresses in the context of surveillance of accidental atmospheric releases. The first part of my thesis addresses the optimization of a permanent network of monitoring of radioactive aerosols in the air, covering France. The second part concerns the problem of targeting of observations in case of an accidental release of radionuclides from a nuclear plant. (author)

  5. Atmospheric Dispersion Modeling of the February 2014 Waste Isolation Pilot Plant Release

    Energy Technology Data Exchange (ETDEWEB)

    Nasstrom, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Piggott, Tom [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lobaugh, Megan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tai, Lydia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pobanz, Brenda [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yu, Kristen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-22

    This report presents the results of a simulation of the atmospheric dispersion and deposition of radioactivity released from the Waste Isolation Pilot Plant (WIPP) site in New Mexico in February 2014. These simulations were made by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL), and supersede NARAC simulation results published in a previous WIPP report (WIPP, 2014). The results presented in this report use additional, more detailed data from WIPP on the specific radionuclides released, radioactivity release amounts and release times. Compared to the previous NARAC simulations, the new simulation results in this report are based on more detailed modeling of the winds, turbulence, and particle dry deposition. In addition, the initial plume rise from the exhaust vent was considered in the new simulations, but not in the previous NARAC simulations. The new model results show some small differences compared to previous results, but do not change the conclusions in the WIPP (2014) report. Presented are the data and assumptions used in these model simulations, as well as the model-predicted dose and deposition on and near the WIPP site. A comparison of predicted and measured radionuclide-specific air concentrations is also presented.

  6. Study of applying the Atmospheric Release Advisory Capability to nuclear power plants

    International Nuclear Information System (INIS)

    Orphan, R.C.

    1978-06-01

    Each utility licensee for a nuclear power reactor is required to minimize the adverse effects from an accidental radionuclide release into the atmosphere. In the past the ability to forecast quantitatively the extent of the hazard from such a release has been limited. Now powerful atmospheric modeling techniques are available to assist nuclear reactor site officials with greatly improved assessments. Lawrence Livermore Laboratory (LLL) has developed a prototype system called the Atmospheric Release Advisory Capability (ARAC) which is designed to integrate the modeling with advanced sensors, data handling techniques, and weather data in order to provide timely, usable advisories to the site officials. The purpose of this project is to examine the ways and means of adapting ARAC for application to many nuclear power reactors widely dispersed across the nation. The project will emphasize the management aspects, including government-industry relationships, technology transfer, organizational structure, staffing, implementing procedures, and costs. Benefits and costs for several alternative systems will be compared. The results will be reviewed and evaluated by the management and staff of the ARAC project at LLL and also by selected staff members of the sponsoring government agency

  7. Real-time modeling of complex atmospheric releases in urban areas

    International Nuclear Information System (INIS)

    Baskett, R.L.; Ellis, J.S.; Sullivan, T.J.

    1994-08-01

    If a nuclear installation in or near an urban area has a venting, fire, or explosion, airborne radioactivity becomes the major concern. Dispersion models are the immediate tool for estimating the dose and contamination. Responses in urban areas depend on knowledge of the amount of the release, representative meteorological data, and the ability of the dispersion model to simulate the complex flows as modified by terrain or local wind conditions. A centralized dispersion modeling system can produce realistic assessments of radiological accidents anywhere in a country within several minutes if it is computer-automated. The system requires source-term, terrain, mapping and dose-factor databases, real-time meteorological data acquisition, three-dimensional atmospheric transport and dispersion models, and experienced staff. Experience with past responses in urban areas by the Atmospheric Release Advisory Capability (ARAC) program at Lawrence Livermore National Laboratory illustrate the challenges for three-dimensional dispersion models

  8. Real-time modelling of complex atmospheric releases in urban areas

    International Nuclear Information System (INIS)

    Baskett, R.L.; Ellis, J.S.; Sullivan, T.J.

    2000-01-01

    If a nuclear installation in or near an urban area has a venting, fire, or explosion, airborne radioactivity becomes the major concern. Dispersion models are the immediate tool for estimating the dose and contamination. Responses in urban areas depend on knowledge of the amount of the release, representative meteorological data, and the ability of the dispersion model to simulate the complex flows as modified by terrain or local wind conditions. A centralised dispersion modelling system can produce realistic assessments of radiological accidents anywhere in a country within several minutes if it is computer-automated. The system requires source-term, terrain, mapping and dose-factor databases, real-time meteorological data acquisition, three-dimensional atmospheric transport and dispersion models, and experienced staff. Experience with past responses in urban areas by the Atmospheric Release Advisory Capability (ARAC) program at Lawrence Livermore National Laboratory illustrate the challenges for three-dimensional dispersion models. (author)

  9. Maxine: A spreadsheet for estimating dose from chronic atmospheric radioactive releases

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bell, Evaleigh [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-24

    MAXINE is an EXCEL© spreadsheet, which is used to estimate dose to individuals for routine and accidental atmospheric releases of radioactive materials. MAXINE does not contain an atmospheric dispersion model, but rather doses are estimated using air and ground concentrations as input. Minimal input is required to run the program and site specific parameters are used when possible. Complete code description, verification of models, and user’s manual have been included.

  10. ARANO - a computer program for the assessment of radiological consequences of atmospheric radioactive releases

    International Nuclear Information System (INIS)

    Savolainen, I.; Vuori, S.

    1980-09-01

    A short description of the calculation possibilities, methods and of the structure of the computer code system ARANO is given, in addition to the input quide. The code can be employed in the calculation of environmental radiological consequences caused by radioactive materials released to atmosphere. Results can be individual doses for different organs at given distances from the release point, collective doses, numbers of persons exceeding given dose limits, numbers of casualties, areas polluted by deposited activity and losses of investments or production due to radioactive contamination. Both a case with a single release and atmospheric dispersion situation and a group of radioactive release and dispersions with discrete probability distributions can be considered. If the radioactive releases or the dispersion conditions are described by probability distributions, the program assesses the magnitudes of the specified effects in all combinations of the release and dispersion situations and then calculates the expectation values and the cumulative probability distributions of the effects. The vertical mixing in the atmosphere is described with a Ksub(Z)-model. In the lateral direction the plume is assumed to be Gaussian, and the release duration can be taken into account in the σsub(y)-values. External gamma dose from the release plume is calculated on the basis of a data file which has been created by 3-dimensional integration. Dose due to inhalation and due to gamma radiation from the contaminated ground are calculated by using appropriate dose conversion factors, which are collected into two mutually alternative block data subprograms. (author)

  11. SUBDOSA: a computer program for calculating external doses from accidental atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Strenge, D.L.; Watson, E.C.; Houston, J.R.

    1975-06-01

    A computer program, SUBDOSA, was developed for calculating external γ and β doses to individuals from the accidental release of radionuclides to the atmosphere. Characteristics of SUBDOSA are: doses from both γ and β radiation are calculated as a function of depth in tissue, summed and reported as skin, eye, gonadal, and total body dose; doses are calculated for releases within each of several release time intervals and nuclide inventories and atmospheric dispersion conditions are considered for each time interval; radioactive decay is considered during the release and/or transit using a chain decay scheme with branching to account for transitions to and from isomeric states; the dose from gamma radiation is calculated using a numerical integration technique to account for the finite size of the plume; and the program computes and lists the normalized air concentrations at ground level as a function of distance from the point of release. (auth)

  12. Impact of methane flow through deformable lake sediments on atmospheric release

    Science.gov (United States)

    Scandella, B.; Juanes, R.

    2010-12-01

    Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

  13. Savannah River Site radioiodine atmospheric releases and offsite maximum doses

    International Nuclear Information System (INIS)

    Marter, W.L.

    1990-01-01

    Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models

  14. The current status of ARAC [Atmospheric Release Advisory Capability] and its application to the Chernobyl event

    International Nuclear Information System (INIS)

    Gudiksen, P.H.; Sullivan, T.J.; Harvey, T.F.

    1986-10-01

    The Atmospheric Release Advisory Capability (ARAC) project, developed by the Lawrence Livermore National Laboratory (LLNL), provides real-time dose assessments and estimates of the extent of surface contamination that may result from an atmospheric release of radioactivity. It utilizes advanced computer-based data communication and processing systems to acquire the meteorological and source term information needed by the three-dimensional atmospheric dispersion models to derive the consequence assessments. The ARAC responded to the recent Chernobyl reactor accident in the Soviet Union by estimating the source term and the radiation dose distribution due to exposure to the radioactive cloud over Europe and the Northern Hemisphere. This analysis revealed that approximately 50% of the estimated core inventories of I-131 and Cs-137 were released. The estimated committed effective dose equivalent due to inhalation of radioactivty during cloud passage is of the order of 10 mrem within parts of Scandinavia and eastern Europe, while most of the populations within central Europe were exposed to levels ranging from 1 to 10 mrem. The amount of Cs-137 released by the Chernobyl accident far exceeds that released by previous reactor accidents, but is only about 6% of the Cs-137 produced by the atmospheric weapon testing programs. 9 refs., 4 figs., 2 tabs

  15. Atmospheric effects of heat release at large power plants

    International Nuclear Information System (INIS)

    Kikuchi, Yukio

    1979-01-01

    In power plants, the thermal efficiency of generating electricity is generally 1/3, the rest 2/3 being carried away by cooling water. To release the heat, there are three alternative methods; i.e. cooling water released into sea, cooling water released into a cooling pond, and cooling of such water with a cooling tower. In the third method, cooling towers are stacks of 10m -- 80m bore, and warm cooling water flowing on the side wall is cooled with atmospheric air. The resultant heated air is discharged as plume from their top. Upon condensation, it becomes visible and then leads to the formation of clouds. In this manner, the weather around the sites of power plants is affected, such as reduction of insolation reaching ground and increase in precipitation. The following matters are described: cooling towers; phenomena and prediction methods of visible plume, cloud formation, increase of precipitation and deposition of drifting waterdrops; and effects of the group of power plants. (J.P.N.)

  16. Water in stars: expected and unexpected

    Science.gov (United States)

    Tsuji, T.; Aoki, W.; Ohnaka, K.

    1999-03-01

    We have confirmed the presence of water in the early M giant α Cet (M1.5III) and supergiant KK Per (M2Iab) by the highest resolution grating mode of SWS, but this result is quite unexpected from present model atmospheres. In late M giant and supergiant stars, water observed originates partly in the photosphere as expected by the model atmospheres, but ISO SWS has revealed that the 2.7 mic\\ absorption bands appear to be somewhat stronger than predicted while 6.5 mic\\ bands weaker, indicating the contamination by an emission component. In the mid-infrared region extending to 45 mic, pure rotation lines of hho\\ appear as distinct emission on the high resolution SWS spectra of 30g Her (M7III) and S Per (M4-7Ia), along with the dust emission at 10, 13, 20 mic\\ and a new unidentified feature at 30 mic. Thus, together with the dust, water contributes to the thermal balance of the outer atmosphere already in the mid-infrared. The excitation temperature of hho\\ gas is estimated to be 500 - 1000 K. In view of this result for late M (super)giants, unexpected water observed in early M (super)giants should also be of non-photospheric in origin. Thus, ISO has finally established the presence of a new component of the outer atmosphere - a warm molecular envelope - in red giant and supergiant stars from early to late types. Such a rather warm molecular envelope will be a site of various activities such as chemical reactions, dust formation, mass-outflow etc.

  17. Dose Assessment Model for Chronic Atmospheric Releases of Tritium

    International Nuclear Information System (INIS)

    Shen Huifang; Yao Rentai

    2010-01-01

    An improved dose assessment model for chronic atmospheric releases of tritium was proposed. The proposed model explicitly considered two chemical forms of tritium.It was based on conservative assumption of transfer of tritiated water (HTO) from air to concentration of HTO and organic beam tritium (OBT) in vegetable and animal products.The concentration of tritium in plant products was calculated based on considering dividedly leafy plant and not leafy plant, meanwhile the concentration contribution of tritium in the different plants from the tritium in soil was taken into account.Calculating the concentration of HTO in animal products, average water fraction of animal products and the average weighted tritium concentration of ingested water based on the fraction of water supplied by each source were considered,including skin absorption, inhalation, drinking water and food.Calculating the annual doses, the ingestion doses were considered, at the same time the contribution of inhalation and skin absorption to the dose was considered. Concentrations in foodstuffs and dose of annual adult calculated with the specific activity model, NEWTRI model and the model proposed by the paper were compared. The results indicate that the model proposed by the paper can predict accurately tritium doses through the food chain from chronic atmospheric releases. (authors)

  18. Simulated atmospheric disperison of radioactive material released in an urban area

    International Nuclear Information System (INIS)

    Akins, R.E.; Church, H.W.; Tierney, M.S.

    1977-01-01

    A combination of Gaussian plume and particle-in-cell techniques is used to simulate the atmospheric transport and dispersion of a puff release of radioactive material. The release is caused by an accident that is assumed to occur during the shipment of the radioactive material through central New York City. The simulation provides estimates of volumetric and surface concentrations of the dispersed material that are used to predict radiation doses incurred by the City's population in the event of an accidental release. In the simulation, the release point is arbitrary and the material is assumed to be either a gas or fine particles. The Gaussian plume model follows cloud concentrations from the release time until times when transport over distances up to 500 m has been achieved. The released cloud may stabilize at street level or above the mean buildings height; at a street intersection or in the middle of the block. The possibility of the formation of multiple clouds, owing to circumstances of wind flow direction and street geometry, is allowed

  19. Decreased atmospheric sulfur deposition across the southeastern U.S.: When will watersheds release stored sulfate?

    Science.gov (United States)

    Rice, Karen C.; Scanlon, Todd M.; Lynch, Jason A.; Cosby, Bernard J.

    2014-01-01

    Emissions of sulfur dioxide (SO2) to the atmosphere lead to atmospheric deposition of sulfate (SO42-), which is the dominant strong acid anion causing acidification of surface waters and soils in the eastern United States (U.S.). Since passage of the Clean Air Act and its Amendments, atmospheric deposition of SO2 in this region has declined by over 80%, but few corresponding decreases in stream-water SO42- concentrations have been observed in unglaciated watersheds. We calculated SO42- mass balances for 27 forested, unglaciated watersheds from Pennsylvania to Georgia, by using total atmospheric deposition (wet plus dry) as input. Many of these watersheds still retain SO42-, unlike their counterparts in the northeastern U.S. and southern Canada. Our analysis showed that many of these watersheds should convert from retaining to releasing SO42- over the next two decades. The specific years when the watersheds crossover from retaining to releasing SO42- correspond to a general geographical pattern of later net watershed release from north to south. The single most important variable that explained the crossover year was the runoff ratio, defined as the ratio of annual mean stream discharge to precipitation. Percent clay content and mean soil depth were secondary factors in predicting crossover year. The conversion of watersheds from net SO42- retention to release anticipates more widespread reductions in stream-water SO42- concentrations in this region.

  20. Atmospheric Release Advisory capability (ARAC) response to the Three Mile Island accident

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Gudiksen, P.H.

    1979-10-01

    This paper discusses the three general classes of support provided by the Atmospheric Release Advisory Capability (ARAC) and describes the role played by ARAC in support of DOE during the Three Mile Island accident in March and April of 1979

  1. Atmospheric Release Advisory Capability (ARAC): development and plans for implementation

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Orphan, R.C.

    1975-01-01

    The Atmospheric Release Advisory Capability (ARAC) is an ERDA-sponsored service planned for nuclear facilities which require a means of real-time prediction of the extent of health hazards that may result from a release of radionuclides or other toxic materials. Since 1973 when the ARAC concept was initiated, a joint feasibility study has been conducted by Lawrence Livermore Laboratory and Savannah River Laboratory, and a prototype component of the system has been built and placed in operation. During the next three years plans are to implement the ARAC service for certain ERDA nuclear facilities. A brief description is presented of the ARAC concept, and progress to date is reported. (U.S.)

  2. Radiological impact of atmospheric releases from a coal-fired power station

    International Nuclear Information System (INIS)

    Aigueperse, J.; Chalabreysse, J.; Coulon, R.; Grauby, A.; Uzzan, G.

    1982-01-01

    As the first stage of a study carried out under contract with the Commission of the European Communities for the comparative assessment of the risks to which the individuals of a regional population are exposed, the paper seeks to evaluate atmospheric releases from a coal-fired thermal power station. The station is of traditional design with an installed capacity of 415MW(e) and uses only lignite-type coal produced from a coal basin situated nearby. Gaseous effluents are released from four stacks. The area close to the station is rural in nature: there are a number of small farms, fairly abundant natural vegetation and some fairly well-populated zones with various industries. The main feature of the weather conditions is the strong prevailing winds in the optimum direction. A radiation measurement campaign involving the main 238 U and 232 Th daughter products was carried out focussing on: (1) the coal burnt in the power station; (2) the solid residues resulting from combustion (fly ash, wet ash); (3) gaseous effluents by means of direct sampling from the two release stacks. The information obtained on the releases has made it possible, with the help of dispersion and transfer models, to evaluate the atmospheric concentration of the different radionuclide released as well as their deposition and presence in the biotope in the plant vicinity. The effective dose equivalents received by persons living in the zone of maximum exposure and consuming food produced in that zone were assessed at approximately 7x10 -5 Sv.a -1 at the end of the plant's operating period. Finally, the main radionuclides were measured at a number of points near the plant with the aim of verifying the model evaluations for a particular situation. (author)

  3. Radiological impact of atmospheric releases from a coal-fired power station

    Energy Technology Data Exchange (ETDEWEB)

    Aigueperse, J; Chalabreysse, J; Coulon, R; Grauby, A [CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Dept. de Protection; Uzzan, G [Association EURATOM-CEA, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Dept. de Protection

    1982-01-01

    As the first stage of a study carried out under contract with the Commission of the European Communities for the comparative assessment of the risks to which the individuals of a regional population are exposed, the paper seeks to evaluate atmospheric releases from a coal-fired thermal power station. The station is of traditional design with an installed capacity of 415MW(e) and uses only lignite-type coal produced from a coal basin situated nearby. Gaseous effluents are released from four stacks. The area close to the station is rural in nature: there are a number of small farms, fairly abundant natural vegetation and some fairly well-populated zones with various industries. The main feature of the weather conditions is the strong prevailing winds in the optimum direction. A radiation measurement campaign involving the main /sup 238/U and /sup 232/Th daughter products was carried out focussing on: (1) the coal burnt in the power station; (2) the solid residues resulting from combustion (fly ash, wet ash); (3) gaseous effluents by means of direct sampling from the two release stacks. The information obtained on the releases has made it possible, with the help of dispersion and transfer models, to evaluate the atmospheric concentration of the different radionuclide released as well as their deposition and presence in the biotope in the plant vicinity. The effective dose equivalents received by persons living in the zone of maximum exposure and consuming food produced in that zone were assessed at approximately 7x10/sup -5/Sv.a/sup -1/ at the end of the plant's operating period. Finally, the main radionuclides were measured at a number of points near the plant with the aim of verifying the model evaluations for a particular situation.

  4. REDUCING AMMONIA CONCENTRATIONS IN ATMOSPHERE AFTER ITS UNPLANNED RELEASE

    Directory of Open Access Journals (Sweden)

    L. V. Amelina

    2017-08-01

    Full Text Available Purpose. The aim of this work is development of numerical model, which allows to calculate the efficiency of neutralizer supply for reduction of air pollution in case of unplanned ammonia emission at the territory of ammonia pump station. The numerical model should allow fast calculating, taking into account the meteorological parameters and buildings situated near the source of toxic chemical emission and equipment for neutralizer supply. Methodology. The developed model is based on the equation for potential flow and equation of pollutant dispersion. To simulate the chemical interaction between ammonia and neutralizer the stoichiometry equation is used. Equation of potential flow is used to compute flow pattern among buildings. To solve the equation for potential flow the Samarskii implicit difference scheme is used. The implicit change-triangle difference scheme is used to solve equation of mass transfer. While for the numerical integration the authors use the rectangular difference grid. Method of porosity technique («markers method» is applied to create the form of comprehensive computational region. Emission of ammonia is modeled using Delta function for point source. Findings. Developed numerical model belongs to the class of «diagnostic models». This model takes into account the main physical factors affecting the process of dispersion of ammonia and neutralizer in the atmosphere, as well as the influence of buildings on admixture dispersion. On the basis of the developed numerical models the authors carried out a computational experiment to estimate the efficiency of neutralizer supply for reduction of air pollution in case of unplanned ammonia release at ammonia pump station. Originality. Developed numerical model allows calculating the flow pattern among buildings and estimating the efficiency of neutralizer supply for reduction of air pollution in the case unplanned ammonia release. Practical value. Model allows performing fast

  5. Screening models for releases of radionuclides to atmosphere, surface water, and ground -- Work sheets

    International Nuclear Information System (INIS)

    1996-01-01

    Three levels of screening for the atmospheric transport pathways and two levels for surface water are presented. The ground has only one screening level. Level 1 is the simplest approach and incorporates a high degree of conservatism. The estimate of the effective dose for this level assumes a concentration based upon the radionuclide concentration at the point of emission to the environment, i.e., at the stack for atmospheric emissions, at the end of the effluent pipe for liquid effluent releases, and at a well because of the buried radioactive material. Levels 2 and 3 are presented for atmospheric releases, and Level 2 for surface water releases only and are more detailed and correspondingly less conservative. Level 2 screening accounts for dispersion in the atmosphere and in surface waters and combines all recognized pathways into the screening factor. For the atmospheric pathway, Level 3 screening includes more definitive pathways analysis. Should the user be found in compliance on the basis of Level 1 screening, no further calculations are required. If the user fails Level 1, the user proceeds to the next level and checks for compliance. This process is repeated until the user passes screening (is in compliance) or no further screening levels exist. If the user fails the final level, professional assistance should be obtained in environmental radiological assessment. Work sheets are designed to lead the user through screening in a step-by-step manner until compliance is demonstrated or it is determined that more sophisticated methods or expertise are needed. Flow diagrams are provided as a guide to identify key steps in the screening process

  6. Atmospheric Release Advisory Capability (ARAC) response to the Three Mile Island accident

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Gudiksen, P.H.

    1980-01-01

    A discussion is presented of the three general classes of support provided by the Atmospheric Release Advisory Capability (ARAC) and describes the role played by ARAC in support of DOE during the Three Mile Island accident in March and April of 1979. 6 refs

  7. ARAC: a centralized computer assisted emergency planning, response, and assessment system for atmospheric releases of toxic material

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Knox, J.B.

    1986-10-01

    The Atmospheric Release Advisory Capability (ARAC) is an emergency planning, response, and assessment service, developed by the US Departments of Energy and Defense, and focused, thus far, on atmospheric releases of nuclear material. For the past 14 years ARAC has responded to over 150 accidents, potential accidents, and major exercises. The most notable accident responses are the COSMOS 954 reentry, the Three Mile Island (TMI-2) accident and subsequent purge of 85 Kr from the containment vessel, the recent UF 6 accident at the Kerr-McGee Plant, Gore, Oklahoma, and the Chernobyl nuclear reactor accident in the Soviet Union. Based on experience in the area of emergency response, developed during the past 14 years, this paper describes the cost effectiveness and other advantages of a centralized emergency planning, response, and assessment service for atmospheric releases of nuclear material

  8. ARAC: a centralized computer-assisted emergency planning, response, and assessment system for atmospheric releases of toxic material

    International Nuclear Information System (INIS)

    Dickerson, M.H.; Knox, J.B.

    1987-01-01

    The Atmospheric Release Advisory Capability (ARAC) is an emergency planning, response, and assessment service, developed by the US Departments of Energy and Defense, and focused, thus far, on atmospheric releases of nuclear material. For the past 14 years ARAC has responded to over 150 accidents, potential accidents, and major exercises. The most notable accident responses are the COSMOS 954 reentry, the Three Mile Island (TMI-2) accident and subsequent purge of 85 Kr from the containment vessel, the recent UF 6 accident at the Kerr-McGee Plant, Gore, Oklahoma, and the Chernobyl nuclear reactor accident in the Soviet Union. Based on experience in the area of emergency response, developed during the past 14 years, this paper describes the cost effectiveness and other advantages of a centralized emergency planning, response, and assessment service for atmospheric releases of nuclear material

  9. 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

  10. Distributed emergency response system to model dispersion and deposition of atmospheric releases

    International Nuclear Information System (INIS)

    Taylor, S.S.

    1985-04-01

    Aging hardware and software and increasing commitments by the Departments of Energy and Defense have led us to develop a new, expanded system to replace the existing Atmospheric Release Advisory Capability (ARAC) system. This distributed, computer-based, emergency response system is used by state and federal agencies to assess the environmental health hazards resulting from an accidental release of radioactive material into the atmosphere. Like its predecessor, the expanded system uses local meteorology (e.g., wind speed and wind direction), as well as terrain information, to simulate the transport and dispersion of the airborne material. The system also calculates deposition and dose and displays them graphically over base maps of the local geography for use by on-site authorities. This paper discusses the limitations of the existing ARAC system. It also discusses the components and functionality of the new system, the technical difficulties encountered and resolved in its design and implementation, and the software methodologies and tools employed in its development

  11. Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, E; Simpson, M; Larsen, S; Gash, J; Aluzzi, F; Lundquist, J; Sugiyama, G

    2010-04-26

    When hazardous material is accidently or intentionally released into the atmosphere, emergency response organizations look to decision support systems (DSSs) to translate contaminant information provided by atmospheric models into effective decisions to protect the public and emergency responders and to mitigate subsequent consequences. The Department of Homeland Security (DHS)-led Interagency Modeling and Atmospheric Assessment Center (IMAAC) is one of the primary DSSs utilized by emergency management organizations. IMAAC is responsible for providing 'a single piont for the coordination and dissemination of Federal dispersion modeling and hazard prediction products that represent the Federal position' during actual or potential incidents under the National Response Plan. The Department of Energy's (DOE) National Atmospheric Release Advisory Center (NARAC), locatec at the Lawrence Livermore National Laboratory (LLNL), serves as the primary operations center of the IMAAC. A key component of atmospheric release decision support systems is meteorological information - models and data of winds, turbulence, and other atmospheric boundary-layer parameters. The accuracy of contaminant predictions is strongly dependent on the quality of this information. Therefore, the effectiveness of DSSs can be enhanced by improving the meteorological options available to drive atmospheric transport and fate models. The overall goal of this project was to develop and evaluate new meteorological modeling capabilities for DSSs based on the use of NASA Earth-science data sets in order to enhance the atmospheric-hazard information provided to emergency managers and responders. The final report describes the LLNL contributions to this multi-institutional effort. LLNL developed an approach to utilize NCAR meteorological predictions using NASA MODIS data for the New York City (NYC) region and demonstrated the potential impact of the use of different data sources and data

  12. Blast from pressurized carbon dioxide released into a vented atmospheric chamber

    Science.gov (United States)

    Hansen, P. M.; Gaathaug, A. V.; Bjerketvedt, D.; Vaagsaether, K.

    2018-03-01

    This study describes the blast from pressurized carbon dioxide (CO2) released from a high-pressure reservoir into an openly vented atmospheric chamber. Small-scale experiments with pure vapor and liquid/vapor mixtures were conducted and compared with simulations. A motivation was to investigate the effects of vent size and liquid content on the peak overpressure and impulse response in the atmospheric chamber. The comparison of vapor-phase CO2 test results with simulations showed good agreement. This numerical code described single-phase gas dynamics inside a closed chamber, but did not model any phase transitions. Hence, the simulations described a vapor-only test into an unvented chamber. Nevertheless, the simulations reproduced the incident shock wave, the shock reflections, and the jet release inside the atmospheric chamber. The rapid phase transition did not contribute to the initial shock strength in the current test geometry. The evaporation rate was too low to contribute to the measured peak overpressure that was in the range of 15-20 kPa. The simulation results produced a calculated peak overpressure of 12 kPa. The liquid tests showed a significantly higher impulse compared to tests with pure vapor. Reducing the vent opening from 0.1 to 0.01 m2 resulted in a slightly higher impulse calculated at 100 ms. The influence of the vent area on the calculated impulse was significant in the vapor-phase tests, but not so clear in the liquid/vapor mixture tests.

  13. An analytical model for radioactive pollutant release simulation in the atmospheric boundary layer

    International Nuclear Information System (INIS)

    Weymar, Guilherme J.; Vilhena, Marco T.; Bodmann, Bardo E.J.; Buske, Daniela; Quadros, Regis

    2013-01-01

    Simulations of emission of radioactive substances in the atmosphere from the Brazilian nuclear power plant Angra 1 are a necessary tool for control and elaboration of emergency plans as a preventive action for possible accidents. In the present work we present an analytical solution for radioactive pollutant dispersion in the atmosphere, solving the time-dependent three-dimensional advection-diffusion equation. The experiment here used as a reference in the simulations consisted of the controlled releases of radioactive tritiated water vapor from the meteorological tower close to the power plant at Itaorna Beach. The wind profile was determined using experimental meteorological data and the micrometeorological parameters were calculated from empirical equations obtained in the literature. We report on a novel analytical formulation for the concentration of products of a radioactive chain released in the atmospheric boundary layer and solve the set of coupled equations for each chain radionuclide by the GILTT solution, assuming the decay of all progenitors radionuclide for each equation as source term. Further we report on numerical simulations, as an explicit but fictitious example and consider three radionuclides in the radioactive chain of Uranium 235. (author)

  14. An analytical model for radioactive pollutant release simulation in the atmospheric boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Weymar, Guilherme J.; Vilhena, Marco T.; Bodmann, Bardo E.J., E-mail: guicefetrs@gmail.com, E-mail: mtmbvilhena@gmail.com, E-mail: bejbodmann@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Buske, Daniela; Quadros, Regis, E-mail: danielabuske@gmail.com, E-mail: quadros99@gmail.com [Universidade Federal de Pelotas (UFPel), Capao do Leao, RS (Brazil). Programa de Pos-Graduacao em Modelagem Matematica

    2013-07-01

    Simulations of emission of radioactive substances in the atmosphere from the Brazilian nuclear power plant Angra 1 are a necessary tool for control and elaboration of emergency plans as a preventive action for possible accidents. In the present work we present an analytical solution for radioactive pollutant dispersion in the atmosphere, solving the time-dependent three-dimensional advection-diffusion equation. The experiment here used as a reference in the simulations consisted of the controlled releases of radioactive tritiated water vapor from the meteorological tower close to the power plant at Itaorna Beach. The wind profile was determined using experimental meteorological data and the micrometeorological parameters were calculated from empirical equations obtained in the literature. We report on a novel analytical formulation for the concentration of products of a radioactive chain released in the atmospheric boundary layer and solve the set of coupled equations for each chain radionuclide by the GILTT solution, assuming the decay of all progenitors radionuclide for each equation as source term. Further we report on numerical simulations, as an explicit but fictitious example and consider three radionuclides in the radioactive chain of Uranium 235. (author)

  15. Analysis of tritium releases to the atmosphere by a CTR

    International Nuclear Information System (INIS)

    Renne, D.S.; Sandusky, W.F.; Dana, M.T.

    1975-08-01

    Removal by atmospheric processes of routinely and accidentally released tritium from a controlled thermonuclear reactor (CTR) was investigated. Based on previous studies, the assumed form of the tritium for this analysis was HTO or tritiated water vapor. Assuming a CTR operation in Morris, Illinois, surface water and ground-level air concentration values of tritium were computed for three space (or time) scales: local (50 Km of a plant), regional (up to 1000 Km of the plant), and global

  16. Atmospheric dispersion and deposition of 131I released from the Hanford Site

    International Nuclear Information System (INIS)

    Ramsdell, J.V. Jr.; Simonen, C.A.; Burk, K.W.; Stage, S.A.

    1996-01-01

    Approximately 2.6 x 10 4 TBq (700,000 Ci) of 131 I were released to the air from reactor fuel processing plants on the Hanford Site in southcentral Washington State from December 1944 through December 1949. The Hanford Environmental Dose Reconstruction Project developed a suite of codes to estimate the doses that might have resulted from these releases. The Regional Atmospheric Transport Code for Hanford Emission Tracking (RATCHET) computer code is part of this suite. The RATCHET code implements a Lagrangian-trajectory, Gaussian-puff dispersion model that uses hourly meterological and release rate data to estimate daily time-integrated air concentrations and surface contamination for use, in dose estimates. In this model, iodine is treated as a mixture of three species (inorganic gases, organic gases, and particles). Model deposition parameters are functions of the mixture and meterological conditions. A resistance model is used to calculate dry deposition velocities. Equilibrium between concentrations in the precipitation and the air near the ground is assumed in calculating wet deposition of gases, and irreversible washout of the particles is assumed. RATCHET explicitly treats the uncertainties in model parameters and meteorological conditions. Uncertainties in 131 I release rates and partitioning among the nominal species are treated by varying model input. The results of 100 model runs for December 1944 through December 1949 indicate that monthly average air concentrations and deposition have uncertainties ranging from a factor of two near the center of the time-integrated plume to more than an order of magnitude near the edge. These results indicate that ∼10% of the 131 I released to the atmosphere decayed during transit in the study area, ∼56% was deposited within the study area, and the remaining 34% was transported out of the study area while still in the air

  17. MAXDOSE-SR: A routine release atmospheric dose model used at SRS

    International Nuclear Information System (INIS)

    Simpkins, A.A.

    2000-01-01

    MAXDOSE-SR is a PC version of the dosimetry code MAXIGASP, which was used to calculate doses to the maximally exposed offsite individual for routine atmospheric releases of radioactive material at the Savannah River Site (SRS). Complete code description, verification of models, and user's manual have been included in this report. Minimal input is required to run the program, and site specific parameters are used when possible

  18. A model for short and medium range dispersion of radionuclides released to the atmosphere

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1979-09-01

    A Working Group was established to give practical guidance on the estimation of the dispersion of radioactive releases to the atmosphere. The dispersion is estimated in the short and medium range, that is from about 100 m to a few tens of kilometres from the source, and is based upon a Gaussian plume model. A scheme is presented for categorising atmospheric conditions and values of the associated dispersion parameters are given. Typical results are presented for releases in specific meteorological conditions and a scheme is included to allow for durations of release of up to 24 hours. Consideration has also been given to predicting longer term average concentrations, typically annual averages, and results are presented which facilitate site specific calculations. The results of the models are extended to 100 km from the source, but the increasing uncertainty with which results may be predicted beyond a few tens of kilometres from the source is emphasised. Three technical appendices provide some of the rationale behind the decisions made in adopting the various models in the proposed dispersion scheme. (author)

  19. Atmospheric plume progression as a function of time and distance from the release point for radioactive isotopes.

    Science.gov (United States)

    Eslinger, Paul W; Bowyer, Ted W; Cameron, Ian M; Hayes, James C; Miley, Harry S

    2015-10-01

    The radionuclide network of the International Monitoring System comprises up to 80 stations around the world that have aerosol and xenon monitoring systems designed to detect releases of radioactive materials to the atmosphere from nuclear explosions. A rule of thumb description of plume concentration and duration versus time and distance from the release point is useful when designing and deploying new sample collection systems. This paper uses plume development from atmospheric transport modeling to provide a power-law rule describing atmospheric dilution factors as a function of distance from the release point. Consider the plume center-line concentration seen by a ground-level sampler as a function of time based on a short-duration ground-level release of a nondepositing radioactive tracer. The concentration C (Bq m(-3)) near the ground varies with distance from the source with the relationship C=R×A(D,C) ×e (-λ(-1.552+0.0405×D)) × 5.37×10(-8) × D(-2.35) where R is the release magnitude (Bq), D is the separation distance (km) from the ground level release to the measurement location, λ is the decay constant (h(-1)) for the radionuclide of interest and AD,C is an attenuation factor that depends on the length of the sample collection period. This relationship is based on the median concentration for 10 release locations with different geographic characteristics and 365 days of releases at each location, and it has an R(2) of 0.99 for 32 distances from 100 to 3000 km. In addition, 90 percent of the modeled plumes fall within approximately one order of magnitude of this curve for all distances. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. AEROS: a real-time emergency response system for atmospheric releases of toxic material

    International Nuclear Information System (INIS)

    Nasstrom, J.S.; Greenly, G.D.

    1986-01-01

    The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory has developed a sophisticated computer-based real-time emergency response system for radiotoxic releases into the atmosphere. The ARAC Emergency Response Operating System (AEROS) has a centralized computer facility linked to remote site computers, meteorological towers, and meteorological data sources. The system supports certain fixed sites, but has the ability to respond to accidents at arbitrary locations. Product quality and response time are optimized by using complex three-dimensional dispersion models; extensive on-line data bases; automated data processing; and an efficient user interface, employing graphical computer displays and computer-displayed forms. Upon notification, the system automatically initiates a response to an emergency and proceeds through preliminary calculations, automatically processing accident information, meteorological data, and model parameters. The model calculations incorporate mass-consistent three-dimensional wind fields, terrain effects, and particle-in-cell diffusion. Model products are color images of dose or deposition contours overlaid on a base map

  1. Presentation and interpretation of field experiments of gaseous UF6 releases in the atmosphere

    International Nuclear Information System (INIS)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G.

    1992-01-01

    An experimental programme concerning the behaviour of UF 6 released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the french Atomic Energy Commission and Eurodif. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get informations about the kinetics of the hydrolysis reaction of the UF 6 , the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles

  2. Presentation and interpretation of field experiments of gaseous UF6 releases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations; Geisse, C.; Iacona, L. [EURODIF, 26 - Pierrelatte (France)

    1992-12-31

    An experimental programme concerning the behaviour of UF{sub 6} released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the french Atomic Energy Commission and Eurodif. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get informations about the kinetics of the hydrolysis reaction of the UF{sub 6}, the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles.

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

    International Nuclear Information System (INIS)

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

    1985-08-01

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

  4. Sugarcane vinasse CO2 gasification and release of ash-forming matters in CO2 and N2 atmospheres.

    Science.gov (United States)

    Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Lindberg, Daniel; Hupa, Mikko

    2016-10-01

    Gasification of sugarcane vinasse in CO2 and the release of ash-forming matters in CO2 and N2 atmospheres were investigated using a differential scanning calorimetry and thermogravimetric analyzer (DSC-TGA) at temperatures between 600 and 800°C. The results showed that pyrolysis is the main mechanism for the release of the organics from vinasse. Release of ash-forming matters in the vinasse is the main cause for vinasse char weight losses in the TGA above 700°C. The losses are higher in N2 than in CO2, and increase considerably with temperature. CO2 gasification also consumes the carbon in the vinasse chars while suppressing alkali release. Alkali release was also significant due to volatilization of KCl and reduction of alkali sulfate and carbonate by carbon. The DSC measured thermal events during heating up in N2 atmosphere that correspond to predicted melting temperatures of alkali salts in the char. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. HARAD, Decay Isotope Concentration from Atmospheric Noble-Gas Release

    International Nuclear Information System (INIS)

    Moore, R.E.

    1986-01-01

    1 - Description of problem or function: HARAD calculates concentrations of radioactive daughters in air following the atmospheric release of a parent radionuclide for a variety of release heights and meteorological conditions. It can be applied most profitably to the assessment of doses to man from the noble gases such as Rn-222, Rn-220, and Xe and Kr isotopes. These gases can produce significant quantities of short-lived particulate daughters in an airborne plume, which are the major contributors to dose. The simultaneous processes of radioactive decay, buildup and environmental loss due to wet and dry deposition on ground surfaces are calculated for a daughter chain in an airborne plume as it is dispersed downwind from a point of release of a parent. 2 - Method of solution: The code evaluates the analytic solution to the set of coupled first order differential equations describing time variation of the concentration of a chain of radionuclides. The analytic solutions assume that the coefficient describing the fractional rate of dry deposition is constant with time. To account for the variation the time coordinate is automatically divided into intervals and a set of average values are used. 3 - Restrictions on the complexity of the problem: - The maximum length of decay chain is 10 nuclides; calculations can be made at a maximum of 24 downwind distances

  6. Evaluating the Effect of Nuclear Power Plant Buildings on the Atmospheric Dispersion Behavior of Released Radioactive Materials

    International Nuclear Information System (INIS)

    Nassar, N.N.; Tawfik, F.S.; Agamy, S.A.; Nagla, T.F.

    2017-01-01

    One of the most important principles in air pollution is to minimize the release of pollutants to the atmosphere, deposition on the ground and promote sufficient dilution of released pollutants within the atmosphere. Building down wash describes the effect that wind flowing over or around buildings create a cavity of reticulating winds in the are a near the buildings. These cavities cause increased vertical dispersion of plumes emitted from stacks on or near the buildings . Often it leads to elevated concentrations downwind of affected stacks. The aim of this work is to evaluate the effect of the building down wash phenomena on the atmospheric dispersion behavior of released radioactive materials from NPP. In this study, a hypothetical scenario is presented involving a point source with varying stack parameters and rectangular shaped buildings (Mille stone Nuclear Power Plant) using meteorological parameters of a chosen day. The concentrations of assumed released radionuclides, taking into consideration the building down wash effect and without are calculated using the AERMOD Model taking into consideration the effect of the type of atmospheric stability class. Also the analysis includes the model predictions for the highest 1-hour cavity concentration. The results show that the size of the cavity zone is not affected by the type of stability class, but is affected by the stack location and buildings shape. On other hand, the distance at which the plume touches the ground is affected by the type of stability class, the stack location and buildings shape. So, strategies for locating buildings need to be considered to maximize dispersion when planning for constructing several reactors and accessory buildings at a nuclear site

  7. Ruthenium release modelling in air and steam atmospheres under severe accident conditions using the MAAP4 code

    International Nuclear Information System (INIS)

    Beuzet, Emilie; Lamy, Jean-Sylvestre; Perron, Hadrien; Simoni, Eric; Ducros, Gérard

    2012-01-01

    Highlights: ► We developed a new modelling of fuel oxidation and ruthenium release in the EDF version of the MAAP4 code. ► We validated this model against some VERCORS experiments. ► Ruthenium release prediction quantitatively and qualitatively well reproduced under air and steam atmospheres. - Abstract: In a nuclear power plant (NPP), a severe accident is a low probability sequence that can lead to core fusion and fission product (FP) release to the environment (source term). For instance during a loss-of-coolant accident, water vaporization and core uncovery can occur due to decay heat. These phenomena enhance core degradation and, subsequently, molten materials can relocate to the lower head of the vessel. Heat exchange between the debris and the vessel may cause its rupture and air ingress. After lower head failure, steam and air entering in the vessel can lead to degradation and oxidation of materials that are still intact in the core. Indeed, Zircaloy-4 cladding oxidation is very exothermic and fuel interaction with the cladding material can decrease its melting temperature by several hundred of Kelvin. FP release can thus be increased, noticeably that of ruthenium under oxidizing conditions. Ruthenium is of particular interest because of its high radio-toxicity due to 103 Ru and 106 Ru isotopes and its ability to form highly volatile compounds, even at room temperature, such as gaseous ruthenium tetra-oxide (RuO 4 ). It is consequently of great need to understand phenomena governing steam and air oxidation of the fuel and ruthenium release as prerequisites for the source term issues. A review of existing data on these phenomena shows relatively good understanding. In terms of oxygen affinity, the fuel is oxidized before ruthenium, from UO 2 to UO 2+x . Its oxidation is a rate-controlling surface exchange reaction with the atmosphere, so that the stoichiometric deviation and oxygen partial pressure increase. High temperatures combined with the presence

  8. Atmospheric dilution factors for radioactive releases from Inshas research reactor, Egypt

    International Nuclear Information System (INIS)

    Abdel Aal, M.M.; Aly, A.I.M.; Tawfik, F.S.

    1994-01-01

    In the frame of assessing the suitability of Inshas site for constructing a new research reactor 20 MW, the meteorological condition are analyzed to determine the most affected population sectors. The atmospheric stability classes are estimated by a developed computer program in which the meteorological data for one year are used as input data. The results indicate that stability class F (moderately stable) is predominant one. The dilution factor is calculated using the computer code XOQDOQ for meteorological evaluation of routine effluent releases at nuclear power stations, which implements regulatory Guide 1.111 for both normal and desert conditions and for ground and elevated releases. The concentration isopleths are plotted and the most affected sector is the southern one with higher values for desert condition than the corresponding normal condition at same distance from the source. 4 fig., 3 tab

  9. Probabilistic siting analysis of nuclear power plants emphasizing atmospheric dispersion of radioactive releases and radiation-induced health effects

    International Nuclear Information System (INIS)

    Savolainen, Ilkka

    1980-01-01

    A presentation is made of probabilistic evaluation schemes for nuclear power plant siting. Effects on health attributable to ionizing radiation are reviewed, for the purpose of assessment of the numbers of the most important health effect cases in light-water reactor accidents. The atmospheric dispersion of radioactive releases from nuclear power plants is discussed, and there is presented an environmental consequence assessment model in which the radioactive releases and atmospheric dispersion of the releases are treated by the application of probabilistic methods. In the model, the environmental effects arising from exposure to radiation are expressed as cumulative probability distributions and expectation values. The probabilistic environmental consequence assessment model has been applied to nuclear power plant site evaluation, including risk-benefit and cost-benefit analyses, and the comparison of various alternative sites. (author)

  10. Presentation and interpretation of field experiments of gaseous UF{sub 6} releases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA/Inst. de Protection et de Surete Nucleaire, Dept. de Protection de l' Environnement et des Installations, Fontenay-aux-Roses (France); Geisse, C.; Iacona, L. [EURODIF/Production, Site de Tricastin, Pierrelatte Cedex (France)

    1992-07-01

    An experimental programme concerning the behaviour of UF{sub 6} released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the French Atomic Energy Commission and EURODIF. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get information about the kinetics of the hydrolysis reaction of the UF{sub 6}, the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles. (author)

  11. HGSYSTEMUF6, Simulating Dispersion Due to Atmospheric Release of Uranium Hexafluoride (UF6)

    International Nuclear Information System (INIS)

    Hanna, G; Chang, J.C.; Zhang, J.X.; Bloom, S.G.; Goode, W.D. Jr; Lombardi, D.A.; Yambert, M.W.

    2001-01-01

    1 - Description of program or function: HGSYSTEMUF6 is a suite of models designed for use in estimating consequences associated with accidental, atmospheric release of Uranium Hexafluoride (UF 6 ) and its reaction products, namely Hydrogen Fluoride (HF), and other non-reactive contaminants which are either negatively, neutrally, or positively buoyant. It is based on HGSYSTEM Version 3.0 of Shell Research LTD., and contains specific algorithms for the treatment of UF 6 chemistry and thermodynamics. HGSYSTEMUF6 contains algorithms for the treatment of dense gases, dry and wet deposition, effects due to the presence of buildings (canyon and wake), plume lift-off, and the effects of complex terrain. The models components of the suite include (1) AEROPLUME/RK, used to model near-field dispersion from pressurized two-phase jet releases of UF6 and its reaction products, (2) HEGADAS/UF6 for simulating dense, ground based release of UF 6 , (3) PGPLUME for simulation of passive, neutrally buoyant plumes (4) UF6Mixer for modeling warm, potentially reactive, ground-level releases of UF 6 from buildings, and (5) WAKE, used to model elevated and ground-level releases into building wake cavities of non-reactive plumes that are either neutrally or positively buoyant. 2 - Methods: The atmospheric release and transport of UF 6 is a complicated process involving the interaction between dispersion, chemical and thermodynamic processes. This process is characterized by four separate stages (flash, sublimation, chemical reaction entrainment and passive dispersion) in which one or more of these processes dominate. The various models contained in the suite are applicable to one or more of these stages. For example, for modeling reactive, multiphase releases of UF 6 , the AEROPLUME/RK component employs a process-splitting scheme which numerically integrates the differential equations governing dispersion, UF 6 chemistry, and thermodynamics. This algorithm is based on the assumption that

  12. WRAITH, Internal and External Doses from Atmospheric Release of Isotopes

    International Nuclear Information System (INIS)

    1984-01-01

    1 - Description of problem or function: WRAITH calculates the atmospheric transport of radioactive material to each of a number of downwind receptor points and the external and internal doses to a reference man at each of the receptor points. 2 - Method of solution: The movement of the released material through the atmosphere is calculated using a bivariate straight-line Gaussian distribution model with Pasquill values for standard deviations. The quantity of material in the released cloud is modified during its transit time to account for radioactive decay and daughter production. External doses due to exposure to the cloud can be calculated using a semi-infinite cloud approximation or a 'finite plume' three-dimensional point-kernel numerical integration technique. Internal doses due to acute inhalation are calculated using the ICRP Task Group Model and a four-segmented gastro- intestinal tract model. Translocation of the material between body compartments and retention in the body compartments are calculated using multiple exponential retention functions. Internal doses to each organ are calculated as sums of cross-organ doses with each target organ irradiated by radioactive material in a number of source organs. All doses are calculated in rads with separate values determined for high-LET and low-LET radiation. 3 - Restrictions on the complexity of the problem: - Doses to only three target organs (total body, red bone marrow, and the lungs) are considered and acute inhalation is the only pathway for material to enter the body. The dose response model is not valid for high-LET radiation other than alphas. The high-LET calculation ignores the contributions of neutrons, spontaneous fission fragments, and alpha recoil nuclei

  13. Mesoscale atmospheric modeling of the July 12, 1992 tritium release from the Savannah River Site

    International Nuclear Information System (INIS)

    Fast, J.D.; O'Steen, B.L.; Addis, R.P.

    1992-01-01

    In August of 1991, the Environmental Transport Group (ETG) began the development of an advanced Emergency Response (ER) system based upon the Colorado State University Regional Atmospheric Modeling System (RAMS). This model simulates the three-dimensional, time-dependent, flow field and thermodynamic structure of the planetary boundary layer (PBL). A companion Lagrangian Particle Dispersion Model (LPDM) simulates contaminant transport based on the flow and turbulence fields generated by RAMS. This paper describes the performance of the advanced ER system in predicting transport and diffusion near the SRS when compared to meteorological and sampling data taken during the July 12, 1992 tritium release. Since PUFF/PLUME and 2DPUF are two Weather INformation and Display (WIND) System atmospheric models that were used to predict the transport and diffusion of the plume at the time of the release, the results from the advanced ER system are also compared to those produced by PUFF/PLUME and 2DPUF

  14. Determination of radiation doses caused by release into the atmosphere by nuclear power plants, based on measurement of emission and immission

    International Nuclear Information System (INIS)

    Ekler, B.; Deme, S.

    2006-01-01

    The radiation impact of nuclear facilities, and the nuclear power plants as well, can be determined by using two methods. The first one calculates the dose of critical group of population based on the release, meteorological and hydrological parameters. The second method gives an estimate of the additional dose caused by the nuclear facility from the radiological measurements in the environment. This article compares this two methods for the release in the atmosphere, and gives an estimate of the relative error. The comparison can be applied for cases when the atmospheric pollution is released from a point type source, so for the conventional power plants as well. (author)

  15. Reconstruction of Atmospheric Tracer Releases with Optimal Resolution Features: Concentration Data Assimilation

    Science.gov (United States)

    Singh, Sarvesh Kumar; Turbelin, Gregory; Issartel, Jean-Pierre; Kumar, Pramod; Feiz, Amir Ali

    2015-04-01

    The fast growing urbanization, industrialization and military developments increase the risk towards the human environment and ecology. This is realized in several past mortality incidents, for instance, Chernobyl nuclear explosion (Ukraine), Bhopal gas leak (India), Fukushima-Daichi radionuclide release (Japan), etc. To reduce the threat and exposure to the hazardous contaminants, a fast and preliminary identification of unknown releases is required by the responsible authorities for the emergency preparedness and air quality analysis. Often, an early detection of such contaminants is pursued by a distributed sensor network. However, identifying the origin and strength of unknown releases following the sensor reported concentrations is a challenging task. This requires an optimal strategy to integrate the measured concentrations with the predictions given by the atmospheric dispersion models. This is an inverse problem. The measured concentrations are insufficient and atmospheric dispersion models suffer from inaccuracy due to the lack of process understanding, turbulence uncertainties, etc. These lead to a loss of information in the reconstruction process and thus, affect the resolution, stability and uniqueness of the retrieved source. An additional well known issue is the numerical artifact arisen at the measurement locations due to the strong concentration gradient and dissipative nature of the concentration. Thus, assimilation techniques are desired which can lead to an optimal retrieval of the unknown releases. In general, this is facilitated within the Bayesian inference and optimization framework with a suitable choice of a priori information, regularization constraints, measurement and background error statistics. An inversion technique is introduced here for an optimal reconstruction of unknown releases using limited concentration measurements. This is based on adjoint representation of the source-receptor relationship and utilization of a weight

  16. Atmosphere dependence of fission products release: The Vercors 4 and 5 experiments

    Energy Technology Data Exchange (ETDEWEB)

    Andre, B.; Ducros, G.; Tourasse, M.; Ferroud-Plattet, M.P. [CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique; Boulaud, D. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    Because of the severe consequences, in terms of radiological and biological effects, of a nuclear accident, the international reactor safety authorities initiated, 25 years ago, numerous experimental programs in order to improve the understanding and the prediction of these situations. In France, the Nuclear Protection and Safety Institute (IPSN) in collaboration with Electricite de France (EDF) co-fund the Heva-Vercors program, since 1983. The experiments are conducted in a shielded hot cell of the LAMA facility at Grenoble. The test specimen is a fuel rod section taken from a power reactor operated by EDF and includes three irradiated pellets in their original cladding. The fuel sample is re-irradiated at low power in the Siloe experimental reactor for seven days in order to recreate the short-lived fission products without inducing any in-pile release. Since the experimental sequence is performed less than 40 hours after the end of the reirradiation, direct measurement of radioactive fission products release is possible using gamma spectrometry. The measurements performed during the tests are essentially aimed at characterising the release kinetics and the total release of fission products and structural materials as a function of fuel temperature and oxidising/reducing conditions of the environment. The four last tests (Vercors 3 to Vercors 6), performed at 2600 K, allowed to measure the kinetic of high and low volatile species release, as well as the total released fraction of non volatile species and the transuranic elements. This paper is devoted to the comparison of the Vercors 4 and Vercors 5 tests. The first one has been conducted up to 2600 K under reducing conditions (hydrogen fluid), after an oxidising period at 1670 K. The second one was performed in a pure steam atmosphere after several plateaus at intermediate temperatures in oxidising conditions. The total release of volatile (Sb, Te, I, Cs) is not significantly modified and a higher release of Mo

  17. MISTRAL V1.1.1: assessing doses from atmospheric releases in normal and off-normal conditions

    International Nuclear Information System (INIS)

    David Kerouanton; Patrick Devin; Malvina Rennesson

    2006-01-01

    Protecting the environment and the public from radioactive and chemical hazards has always been a top priority for all companies operating in the nuclear domain. In this scope, SGN provides all the services the nuclear industry needs in environmental studies especially in relation to the impact assessment in normal operating conditions and risk assessment in off-normal conditions. In order to quantify dose impact on members of the public due to atmospheric releases, COGEMA and SGN developed MISTRAL V1.1.1 code. Dose impact depends strongly on dispersion of radionuclides in atmosphere. The main parameters involved in dispersion characterization are wind velocity and direction, rain, diffusion conditions, coordinates of the point of observation and stack elevation. MISTRAL code implements DOURY and PASQUILL Gaussian plume models which are widely used in the scientific community. These models, applicable for distances of transfer ranging from 100 m up to 30 km, are used to calculate atmospheric concentration and deposit at different distances from the point of release. MISTRAL allows the use of different dose regulations or dose coefficient databases such as: - ICRP30 and ICPR71 for internal doses (inhalation, ingestion) - Despres/Kocher database or US-EPA Federal Guidance no.12 (ICPR72 for noble gases) for external exposure (from plume or ground). The initial instant of the release can be considered as the origin of time or a date format can be specified (could be useful in a crisis context). While the context is specified, the user define the meteorological conditions of the release. In normal operating mode (routine releases), the user gives the annual meteorological scheme. The data can be recorded in the MISTRAL meteorological database. In off-normal conditions mode, MISTRAL V1.1 allows the use of successive release stages for which the user gives the duration, the meteorological conditions, that is to say stability class, wind speed and direction and rainfall

  18. Influence of stability classification on atmospheric diffusion calculations for elevated releases over a terrain of major roughness

    International Nuclear Information System (INIS)

    Hu Erbang

    1988-01-01

    A series (22) of atmospheric tracer experiments with 100m release height have been performed at the kernforschungszentrum karlsruhe (KfK) of West Germany over a terrain of major roughness (Z 0 = 1.5 m). The concentration data of the tracers are statistically analysed in which 5 methods of stability classification are used. The results show that the normalized diffusion factors predicted by Gaussian plume dispersion model is in good agreement with the observed ones for elevated releases over a terrain of major roughness. Differnent sets of dispersion parameters could be obtained for the same series of atmospheric tracer experiments if different methods of classification are applied. The same method of stability classification should be used for the application of these dispersion parameters to evaluate the environment impact

  19. Hydrogen Storage and Release Properties of Transition Metal-Added Magnesium Hydride Alloy Fabricated by Grinding in a Hydrogen Atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Sung Nam; Song, Myoung Youp [Chonbuk National University, Jeonju (Korea, Republic of); Park, Hye Ryoung [Chonnam National University, Gwangju (Korea, Republic of)

    2016-07-15

    90 wt% MgH{sub 2}+5 wt% Ni+2.5 wt% Fe+2.5 wt% Ti (called MgH{sub 2}+Ni+Fe+Ti), a hydrogen storage and release material, was fabricated by grinding in a hydrogen atmosphere, and then its quantities of stored and released hydrogen as a function of time were examined. A nanocrystalline MgH{sub 2}+Ni+Fe+Ti specimen was made by grinding in a hydrogen atmosphere and subsequent hydrogen storage-release cycling. The crystallite size of Mg and the strain of the Mg crystallite after ten hydrogen storage-release cycles, which were obtained using the Williamson-Hall method, were 38.6 (±1.4) nm and 0.025 (±0.0081) %, respectively. The MgH{sub 2}+Ni+Fe+Ti sample after the process of grinding in a hydrogen atmosphere was highly reactive with hydrogen. The sample exhibited an available storage capacity of hydrogen (the amount of hydrogen stored during 60 minutes) of about 5.7 wt%. At the first cycle, the MgH2+Ni+Fe+Ti sample stored hydrogen of 5.53 wt% in 5 minutes, 5.66 wt% in 10 minutes and 5.73 wt% in 60 minutes at 573 K and 12 bar of hydrogen. The MgH{sub 2}+Ni+Fe+Ti after activation released hydrogen of 0.56 wt% in 5 minutes, 1.26 wt% in 10 minutes, 2.64 wt% in 20 minutes, 3.82 wt% in 30 minutes, and 5.03 wt% in 60 minutes.

  20. Impact of atmospheric release in stable night meteorological conditions; can emergency models predict dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Connan, O.; Hebert, D.; Solier, L.; Voiseux, C.; Lamotte, M.; Laguionie, P.; Maro, D.; Thomas, L. [IRSN/PRP-ENV/SERIS/LRC (France)

    2014-07-01

    Atmospheric dispersion of pollutant or radionuclides in stratified meteorological condition, i.e. especially when weather conditions are very stable, mainly at night, is still poorly understood and not well apprehended by the operational atmospheric dispersion models. However, correctly predicting the dispersion of a radioactive plume, and estimating the radiological consequences for the population, following an unplanned atmospheric release of radionuclides are crucial steps in an emergency response. To better understand dispersion in these special weather conditions, IRSN performed a series of 22 air sampling campaigns between 2010 and 2013 in the vicinity of the La Hague nuclear reprocessing plant (AREVA - NC, France), at distances between 200 m and 3000 m from the facility. Krypton-85 ({sup 85}Kr), a b-and g-emitting radionuclide, released during the reprocessing of spent nuclear fuel was used as a non-reactive tracer of radioactive plumes. Experimental campaigns were realized in stability class stable or very stable (E or F according to Pasquill classification) 18 times, and in neutral conditions (D according to Pasquill classification) 4 times. During each campaign, Krypton-85 real time measurement were made to find the plume around the plant, and then integrated samples (30 min) were collected in bag perpendicularly to the assumed wind direction axis. After measurement by gamma spectrometry, we have, when it was possible, estimate the point of impact and the width of the plume. The objective was to estimate the horizontal dispersion (width) of the plume at ground level in function of the distance and be able to calculate atmospheric transfer coefficients. In a second step, objective was to conclude on the use of common model and on their uncertainties. The results will be presented in terms of impact on the near-field. They will be compared with data obtained in previous years in neutral atmospheric conditions, and finally the results will be confronted with

  1. The legacy of Cf-252 operations at Savannah River Technology Center: Continuous releases of radioiodine to the atmosphere

    International Nuclear Information System (INIS)

    Kantelo, M.V.; Crandall, B.S.

    1992-01-01

    The iodine isotopes I-132, 1-133, I-134, and I-135, which have half-lives ranging from 53 minutes to 21 hours, are measured in the atmospheric effluent from the Savannah River Technology Center (SRTC) at the Savannah River Site (SRS) near Aiken, South Carolina. SRS is operated by Westinghouse Savannah River Company for the US Department of Energy (DOE). The isotopes' release rates range from 10 to 300 microcuries per week compared to the rate. The resulting annual dose from all iodine isotopes is minor; it comprises 0.01 percent of the total offsite dose due to atmospheric releases from SRS in 1990. Circumstantial evidence indicates the radioiodine originates from traces of unencapsulated Cf-252. The determination that spontaneous fission of Cf-252 is the source of the radioiodine has several ramifications. Radioactive fission-product isotopes of the noble gas elements krypton and xenon must also be released. Noble gases are more volatile and mobile than iodine. Also, the released iodine isotopes decay to xenon isotopes. The noble gases decay to non-gaseous elements that are transported along with radioiodine to the terrestrial environment by deposition from the SRTC plume. Only Sr-89 is believed to accumulate sufficiently in the environment to approach detectable levels. Given similar conditions in earlier years, releases of short-lived radioiodine have occurred undetected in routine monitoring since the early 1970s. Release rates 20 years ago would have been 200 times greater than current release rates. This report documents preliminary experiments conducted by SRTC and Environmental Monitoring Section (EMS) scientists. The release process and the environmental impact of fission products from Cf-252 should be thoroughly researched

  2. Factors affecting release of ethanol vapour in active modified atmosphere packaging systems for horticultural products

    Directory of Open Access Journals (Sweden)

    Weerawate Utto

    2014-04-01

    Full Text Available The active modified atmosphere packaging (active MAP system , which provides interactive postharvest control , using ethanol vapour controlled release, is one of the current interests in the development of active packaging for horticultural products. A number of published research work have discussed the relationship between the effectiveness of ethanol vapour and its concentration in the package headspace, including its effect on postharvest decay and physiological controls. This is of importance because a controlled release system should release and maintain ethanol vapour at effective concentrations during the desired storage period. A balance among the mass transfer processes of ethanol vapour in the package results in ethanol vapour accumulation in the package headspace. Key factors affecting these processes include ethanol loading, packaging material, packaged product and storage environment (temperature and relative h umidity. This article reviews their influences and discusses future work required to better understand their influences on ethanol vapour release and accumulations in active MAP.

  3. Application of PC-CREAM in the Netherlands. Dose impact due to atmospheric releases

    International Nuclear Information System (INIS)

    Eleveld, H.; Twenhoefel, C.J.W.; Pruppers, M.J.M.

    1999-01-01

    A methodology to assess the radiological impact of routine releases, CREAM, was developed at the National Radiological Protection Board (UK). The software implementation of that methodology to the PC platform, PC-CREAM, has been compared to the Dutch regulation guidelines. The results of the PC-CREAM software and previous RIVM studies are compared for two specific reference situations and eleven naturally occurring radionuclides. The methodology in the submodels in PC-CREAM is also studied and compared to the Dutch regulation guidelines. The assessment of the radiological impact for atmospheric releases using PC-CREAM showed good agreement with the results obtained in previous RIVM studies. Some changes and additions in the methodology are proposed to be able to calculate the radiological impact using PC-CREAM in other relevant reference situations

  4. Methodology for prediction and estimation of consequences of possible atmospheric releases of hazardous matter: 'Kursk' submarine study

    Directory of Open Access Journals (Sweden)

    A. Baklanov

    2003-01-01

    Full Text Available There are objects with some periods of higher than normal levels of risk of accidental atmospheric releases (nuclear, chemical, biological, etc.. Such accidents or events may occur due to natural hazards, human errors, terror acts, and during transportation of waste or various operations at high risk. A methodology for risk assessment is suggested and it includes two approaches: 1 probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2 forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach could be applied during the preparation stage, and the second - during the operation stage. The suggested methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning of the ``Kursk" nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137Cs showed that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allowed to identify the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, the forecasts of possible consequences during phases of the high and medium potential risk levels based on a unit hypothetical release (e.g. 1 Bq are performed. The analysis showed that the possible deposition fractions of 10-11 (Bq/m2 over the Kola Peninsula, and 10-12 - 10-13 (Bq/m2 for the remote areas of the Scandinavia and Northwest Russia could be observed. The suggested methodology may be used successfully for any potentially dangerous object involving risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature.

  5. Methodology for prediction and estimation of consequences of possible atmospheric releases of hazardous matter: "Kursk"? submarine study

    Science.gov (United States)

    Baklanov, A.; Mahura, A.; Sørensen, J. H.

    2003-03-01

    There are objects with some periods of higher than normal levels of risk of accidental atmospheric releases (nuclear, chemical, biological, etc.). Such accidents or events may occur due to natural hazards, human errors, terror acts, and during transportation of waste or various operations at high risk. A methodology for risk assessment is suggested and it includes two approaches: 1) probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2) forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach could be applied during the preparation stage, and the second - during the operation stage. The suggested methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning) of the "Kursk" nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137Cs) showed that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allowed to identify the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, the forecasts of possible consequences during phases of the high and medium potential risk levels based on a unit hypothetical release are performed. The analysis showed that the possible deposition fractions of 1011 over the Kola Peninsula, and 10-12 - 10-13 for the remote areas of the Scandinavia and Northwest Russia could be observed. The suggested methodology may be used successfully for any potentially dangerous object involving risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature.

  6. Methodology for prediction and estimation of consequences of possible atmospheric releases of hazardous matter: "Kursk" submarine study

    Science.gov (United States)

    Baklanov, A.; Mahura, A.; Sørensen, J. H.

    2003-06-01

    There are objects with some periods of higher than normal levels of risk of accidental atmospheric releases (nuclear, chemical, biological, etc.). Such accidents or events may occur due to natural hazards, human errors, terror acts, and during transportation of waste or various operations at high risk. A methodology for risk assessment is suggested and it includes two approaches: 1) probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2) forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach could be applied during the preparation stage, and the second - during the operation stage. The suggested methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning) of the ``Kursk" nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137Cs) showed that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allowed to identify the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, the forecasts of possible consequences during phases of the high and medium potential risk levels based on a unit hypothetical release (e.g. 1 Bq) are performed. The analysis showed that the possible deposition fractions of 10-11 (Bq/m2) over the Kola Peninsula, and 10-12 - 10-13 (Bq/m2) for the remote areas of the Scandinavia and Northwest Russia could be observed. The suggested methodology may be used successfully for any potentially dangerous object involving risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature.

  7. Development of a code to simulate dispersion of atmospheric released tritium gas in the environmental media and to evaluate doses. TRIDOSE

    International Nuclear Information System (INIS)

    Murata, Mikio; Noguchi, Hiroshi; Yokoyama, Sumi

    2000-11-01

    A computer code (TRIDOSE) was developed to assess the environmental impact of atmospheric released tritium gas (T 2 ) from nuclear fusion related facilities. The TRIDOSE simulates dispersion of T 2 and resultant HTO in the atmosphere, land, plant, water and foods in the environment, and evaluates contamination concentrations in the media and exposure doses. A part of the mathematical models in TRIDOSE were verified by comparison of the calculation with the results of the short range (400 m) dispersion experiment of HT gas performed in Canada postulating a short-time (30 minutes) accidental release. (author)

  8. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2012-03-01

    Full Text Available On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions into the atmosphere of two isotopes, the noble gas xenon-133 (133Xe and the aerosol-bound caesium-137 (137Cs, which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined it with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 15.3 (uncertainty range 12.2–18.3 EBq, which is more than twice as high as the total release from Chernobyl and likely the largest radioactive noble gas release in history. The entire noble gas inventory of reactor units 1–3 was set free into the atmosphere between 11 and 15 March 2011. In fact, our release estimate is higher than the entire estimated 133Xe inventory of the Fukushima Dai-ichi nuclear power plant, which we explain with the decay of iodine-133 (half-life of 20.8 h into 133Xe. There is strong evidence that the 133Xe release started before the first active venting was made, possibly indicating structural damage to reactor components and/or leaks due to overpressure which would have allowed early release of noble gases. For 137

  9. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant. Determination of the source term, atmospheric dispersion, and deposition

    International Nuclear Information System (INIS)

    Stohl, A.; Burkhart, J.F.; Eckhardt, S.; Seibert, P.; Arnold, D.; Technical Univ. of Catalonia, Barcelona; Tapia, C.; Vargas, A.; Yasunari, T.J.

    2012-01-01

    On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions into the atmosphere of two isotopes, the noble gas xenon-133 ("1"3"3Xe) and the aerosol-bound caesium-137 ("1"3"7Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined it with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for "1"3"7Cs, measurements of bulk deposition. Regarding "1"3"3Xe, we find a total release of 15.3 (uncertainty range 12.2-18.3) EBq, which is more than twice as high as the total release from Chernobyl and likely the largest radioactive noble gas release in history. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. In fact, our release estimate is higher than the entire estimated "1"3"3Xe inventory of the Fukushima Dai-ichi nuclear power plant, which we explain with the decay of iodine-133 (half-life of 20.8 h) into "1"3"3Xe. There is strong evidence that the "1"3"3Xe release started before the first active venting was made, possibly indicating structural damage to reactor components and/or leaks due to overpressure which would have allowed early release of noble gases. For "1"3"7Cs, the inversion results give a total emission of 36.6 (20.1-53.1) PBq, or about

  10. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant. Determination of the source term, atmospheric dispersion, and deposition

    Energy Technology Data Exchange (ETDEWEB)

    Stohl, A.; Burkhart, J.F.; Eckhardt, S. [NILU - Norwegian Institute for Air Research, Kjeller (Norway); Seibert, P. [Univ. of Natural Resources and Life Sciences, Vienna (Austria). Inst. of Meteorology; Wotawa, G. [Central Institute for Meteorology and Geodynamics, Vienna (Austria); Arnold, D. [Univ. of Natural Resources and Life Sciences, Vienna (Austria). Inst. of Meteorology; Technical Univ. of Catalonia, Barcelona (Spain). Inst. of Energy Technologies; Tapia, C. [Technical Univ. of Catalonia, Barcelona (Spain). Dept. of Physics and Nucelar Engineering; Vargas, A. [Technical Univ. of Catalonia, Barcelona (Spain). Inst. of Energy Technologies; Yasunari, T.J. [Univs. Space Research Association, Columbia, MD (United States). Goddard Earth Sciences and Technology and Research

    2012-07-01

    On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions into the atmosphere of two isotopes, the noble gas xenon-133 ({sup 133}Xe) and the aerosol-bound caesium-137 ({sup 137}Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined it with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for {sup 137}Cs, measurements of bulk deposition. Regarding {sup 133}Xe, we find a total release of 15.3 (uncertainty range 12.2-18.3) EBq, which is more than twice as high as the total release from Chernobyl and likely the largest radioactive noble gas release in history. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. In fact, our release estimate is higher than the entire estimated {sup 133}Xe inventory of the Fukushima Dai-ichi nuclear power plant, which we explain with the decay of iodine-133 (half-life of 20.8 h) into {sup 133}Xe. There is strong evidence that the {sup 133}Xe release started before the first active venting was made, possibly indicating structural damage to reactor components and/or leaks due to overpressure which would have allowed early release of noble gases. For {sup 137}Cs, the inversion results give a total emission of 36

  11. An interactive computer model for the assessment of continuous release atmospheric transfers

    International Nuclear Information System (INIS)

    Pages, P.; Rancillac, F.

    1983-05-01

    The purpose of the model is to assess air concentrations and soil deposits following a continuous release of gaseous effluents. This is usually part of the problem of assessing the consequences of normal operation of a plant. The atmospheric dispersion model used is the gaussian plume model according to DOURY's scheme. Ground reflexion, the presence of an inversion layer and removal processes (by dry or wet deposition and radioactive decay type) are taken into account. Air and ground concentrations are computed around the release point according to an arbitrary grid with spatial coordinates and accounting for annual frequencies of meteorological conditions. The methodology is presented in detail and assumptions are clearly stated. A conversational structured computer program has been set up in APL which allows to get results easily and to test their sensitivity to various assumptions concerning both input data and model parameters. As an example an application of the model with real data and results is given [fr

  12. Atmospheric Rawinsonde and Pigeon Release Data Implicate Infrasound as the Long- Range Map Cue in Avian Navigation

    Science.gov (United States)

    Hagstrum, J. T.

    2007-12-01

    Pigeons ( Columba livia) and other birds released from distant familiar and unfamiliar sites generally head in the homeward (loft) direction, but often vanish from view or radio contact consistently off the exact homeward bearing. At some sites the deviation can be a significant and stable amount, while at other sites birds can appear to become completely lost and depart in random directions. These deviations or biases can change from hour to hour, day to day, and year to year, but have not, over the last ~50 years of intensive research, been related to any atmospheric factor. They are, however, still considered to reflect significant irregularities in the pigeons' "map" function. Celestial and geomagnetic "compasses" have been shown to orient avian flight, but how pigeons determine their location in order to select the correct homeward bearing remains controversial. At present the debate is primarily between workers advocating an olfactory "map" and those advocating variations in the direction and intensity of the geomagnetic field as map functions. Alternatively, infrasonic cues can travel 1000s of km in the atmosphere with little attenuation, and can be detected in the laboratory by pigeons at frequencies down to 0.05 Hz. Although infrasound has been considered as a navigational tool for homing and migratory birds, little supporting evidence of its use has been found. Infrasonic ray paths in the atmosphere are controlled primarily by temperature and secondarily by wind. Assuming birds use infrasonic cues, atmospheric conditions could cause the perplexing changes (both geographic and temporal) observed in the mean vanishing bearings (MVBs) of pigeons released from experimental sites. To test for correlations between MVBs and tropospheric conditions, release data collected by the late W.T. Keeton between 1968 and 1980 from around the Cornell University lofts in upstate NY are compared to rawinsonde data from stations near Buffalo and Albany. For example, birds

  13. Development of a code to simulate dispersion of atmospheric released tritium gas in the environmental media and to evaluate doses. TRIDOSE

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Mikio [Nuclear Engineering Co., Ltd., Hitachi, Ibaraki (Japan); Noguchi, Hiroshi; Yokoyama, Sumi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-11-01

    A computer code (TRIDOSE) was developed to assess the environmental impact of atmospheric released tritium gas (T{sub 2}) from nuclear fusion related facilities. The TRIDOSE simulates dispersion of T{sub 2} and resultant HTO in the atmosphere, land, plant, water and foods in the environment, and evaluates contamination concentrations in the media and exposure doses. A part of the mathematical models in TRIDOSE were verified by comparison of the calculation with the results of the short range (400 m) dispersion experiment of HT gas performed in Canada postulating a short-time (30 minutes) accidental release. (author)

  14. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    Energy Technology Data Exchange (ETDEWEB)

    Katata, G.; Chino, M.; Kobayashi, T. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan); and others

    2015-07-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I{sub 2} and CH{sub 3}I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of

  15. Atmospheric 14C changes resulting from fossil fuel CO2 release and cosmic ray flux variability

    International Nuclear Information System (INIS)

    Stuiver, M.; Quay, P.D.

    1981-01-01

    A high-precision tree-ring record of the atmospheric 14 C levels between 1820 and 1954 is presented. Good agreement is obtained between measured and model calculated 19th and 20th century atmospheric δ 14 C levels when both fossil fuel CO 2 release and predicted natural variations in 14 C production are taken into account. The best fit is obtained by using a box-diffusion model with an oceanic eddy diffusion coefficient of 3 cm 2 /s, a CO 2 atmosphere-ocean gas exchange rate of 21 moles msup(-2) yrsup(-1) and biospheric residence time of 60 years. For trees in the state of Washington the measured 1949-1951 atmospheric δ 14 C level was 20.0 +- 1.2per mille below the 1855-1864 level. Model calculations indicate that in 1950 industrial CO 2 emissions are responsible for at least 85% of the δ 14 C decline, whereas natural variability accounts for the remaining 15%. (orig.)

  16. Radiation shielding provided by residential houses in Japan in reactor accidents accompanied with atmospheric release

    International Nuclear Information System (INIS)

    Yamaguchi, Yasuhiro; Minami, Kentaro

    1991-01-01

    The present report describes the radiation shielding effect of houses in Japan against the radioactive cloud resulting from a major reactor accident accompanied with atmospheric release. The shielding factor of houses, the ratio of indoor exposure rate to outdoor one, has been studied for the semi-infinite and finite clouds which contain γ-emitting radionuclides released from a reactor facility. The shielding factor of houses against γ-rays from the radioactive cloud decreases gradually with release delay time and keeps a minimum during the period from 50 to 1000 hours after reactor shutdown while 133 Xe predominates in the cloud. Radioiodines mixed in the cloud raise slightly the shielding factor, and the factor depends little on the shape of the cloud. A set of shielding factors for the use of emergency planning was consequently proposed as 0.4 for simple ferroconcrete residential house and 0.9 for other ordinary ones. (author)

  17. Modeling of methane bubbles released from large sea-floor area: Condition required for methane emission to the atmosphere

    OpenAIRE

    Yamamoto, A.; Yamanaka, Y.; Tajika, E.

    2009-01-01

    Massive methane release from sea-floor sediments due to decomposition of methane hydrate, and thermal decomposition of organic matter by volcanic outgassing, is a potential contributor to global warming. However, the degree of global warming has not been estimated due to uncertainty over the proportion of methane flux from the sea-floor to reach the atmosphere. Massive methane release from a large sea-floor area would result in methane-saturated seawater, thus some methane would reach the atm...

  18. Atmospheric release model for the E-area low-level waste facility: Updates and modifications

    International Nuclear Information System (INIS)

    None, None

    2017-01-01

    The atmospheric release model (ARM) utilizes GoldSim® Monte Carlo simulation software (GTG, 2017) to evaluate the flux of gaseous radionuclides as they volatilize from E-Area disposal facility waste zones, diffuse into the air-filled soil pores surrounding the waste, and emanate at the land surface. This report documents the updates and modifications to the ARM for the next planned E-Area PA considering recommendations from the 2015 PA strategic planning team outlined by Butcher and Phifer.

  19. Atmospheric release model for the E-area low-level waste facility: Updates and modifications

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-11-16

    The atmospheric release model (ARM) utilizes GoldSim® Monte Carlo simulation software (GTG, 2017) to evaluate the flux of gaseous radionuclides as they volatilize from E-Area disposal facility waste zones, diffuse into the air-filled soil pores surrounding the waste, and emanate at the land surface. This report documents the updates and modifications to the ARM for the next planned E-Area PA considering recommendations from the 2015 PA strategic planning team outlined by Butcher and Phifer.

  20. Evacuation emergency response model coupling atmospheric release advisory capability output

    International Nuclear Information System (INIS)

    Rosen, L.C.; Lawver, B.S.; Buckley, D.W.; Finn, S.P.; Swenson, J.B.

    1983-01-01

    A Federal Emergency Management Agency (FEMA) sponsored project to develop a coupled set of models between those of the Lawrence Livermore National Laboratory (LLNL) Atmospheric Release Advisory Capability (ARAC) system and candidate evacuation models is discussed herein. This report describes the ARAC system and discusses the rapid computer code developed and the coupling with ARAC output. The computer code is adapted to the use of color graphics as a means to display and convey the dynamics of an emergency evacuation. The model is applied to a specific case of an emergency evacuation of individuals surrounding the Rancho Seco Nuclear Power Plant, located approximately 25 miles southeast of Sacramento, California. The graphics available to the model user for the Rancho Seco example are displayed and noted in detail. Suggestions for future, potential improvements to the emergency evacuation model are presented

  1. Oxidation of siloxanes during biogas combustion and nanotoxicity of Si-based particles released to the atmosphere.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2014-01-01

    Siloxanes have been detected in the biogas produced at municipal solid waste landfills and wastewater treatment plants. When oxidized, siloxanes are converted to silicon oxides. The objectives of this study were to evaluate the transformation of siloxanes and potential nanotoxicity of Si-based particles released to the atmosphere from the gas engines which utilize biogas. Data available from nanotoxicity studies were used to assess the potential health risks associated with the inhalation exposure to Si-based nanoparticles. Silicon dioxide formed from siloxanes can range from 5 nm to about 100 nm in diameter depending on the combustion temperature and particle clustering characteristics. In general, silicon dioxide particles formed during from combustion process are typically 40-70 nm in diameter and can be described as fibrous dusts and as carcinogenic, mutagenic, astmagenic or reproductive toxic (CMAR) nanoparticles. Nanoparticles deposit in the upper respiratory system, conducting airways, and the alveoli. Size ranges between 5 and 50 nm show effective deposition in the alveoli where toxic effects are higher. In this study the quantities for the SiO₂ formed and release during combustion of biogas were estimated based on biogas utilization characteristics (gas compositions, temperature). The exposure to Si-based particles and potential effects in humans were analyzed in relation to their particle size, release rates and availability in the atmosphere. The analyses showed that about 54.5 and 73 kg/yr of SiO₂ can be released during combustion of biogas containing D4 and D5 at 14.1 mg/m(3) (1 ppm) and 15.1 mg/m(3) (1ppm), respectively, per MW energy yield. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    Science.gov (United States)

    Stohl, A.; Seibert, P.; Wotawa, G.; Arnold, D.; Burkhart, J. F.; Eckhardt, S.; Tapia, C.; Vargas, A.; Yasunari, T. J.

    2012-04-01

    This presentation will show the results of a paper currently under review in ACPD and some additional new results, including more data and with an independent box modeling approach to support some of the findings of the ACPD paper. On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP) developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4-20.0) EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started early, before active venting was performed. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3-50.1) PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14-15 March but were generally high from 12 until 19 March, when they

  3. PAVAN: an atmospheric-dispersion program for evaluating design-basis accidental releases of radioactive materials from nuclear power stations

    International Nuclear Information System (INIS)

    Bander, T.J.

    1982-11-01

    This report provides a user's guide for the NRC computer program, PAVAN, which is a program used by the US Nuclear Regulatory Commission to estimate downwind ground-level air concentrations for potential accidental releases of radioactive material from nuclear facilities. Such an assessment is required by 10 CFR Part 100 and 10 CFR Part 50. The program implements the guidance provided in Regulatory Guide 1.145, Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants. Using joint frequency distributions of wind direction and wind speed by atmospheric stability, the program provides relative air concentration (X/Q) values as functions of direction for various time periods at the exclusion area boundary (EAB) and the outer boundary of the low population zone (LPZ). Calculations of X/Q values can be made for assumed ground-level releases (e.g., through building penetrations and vents) or elevated releases from free-standing stacks. Various options may be selected by the user. They can account for variation in the location of release points, additional plume dispersion due to building wakes, plume meander under low wind speed conditions, and adjustments to consider non-straight trajectories. It computes an effective plume height using the physical release height which can be reduced by inputted terrain features. It cannot handle multiple emission sources. A description of the main program and all subroutines is provided. Also included as appendices are a complete listing of the program and two test cases with the required data inputs and the resulting program outputs

  4. Field studies of the atmospheric processing of radionuclides released at Chernobyl

    International Nuclear Information System (INIS)

    Slinn, W.G.N.; Brodzinski, R.L.; Busness, K.M.

    1987-01-01

    This report gives a summary description of the goals and execution of field studies to characterize the radionuclides released from Chernobyl and to examine their long-range atmospheric transport and processing. Starting on April 28, 1986, an intensive planning and preparation effort was mounted over a very short time intercept and characterize the Chernobyl plume on its arrival over the western US. During the execution of these studies, they had very little firm information (beyond their own measurements and trajectory estimates) to confirm the location of the Chernobyl plume. On May 20, 1986, the studies were terminated, after extensive airborne sampling of air, cloud water, precipitation, soil, and vegetation as the plume traversed the western and central US and moved into Canada

  5. Fate and potential environmental effects of methylenediphenyl diisocyanate and toluene diisocyanate released into the atmosphere.

    Science.gov (United States)

    Tury, Bernard; Pemberton, Denis; Bailey, Robert E

    2003-01-01

    Information from a variety of sources has been collected and summarized to facilitate an overview of the atmospheric fate and potential environmental effects of emissions of methylenediphenyl diisocyanate (MDI) or toluene diisocyanate (TDI) to the atmosphere. Atmospheric emissions of both MDI and TDI are low, both in terms of concentration and mass, because of their low volatility and the need for careful control over all aspects of their lifecycle from manufacture through disposal. Typical emission losses for TDI are 25 g/t of TDI used in slabstock foam production. MDI emission losses are lower, often less than 1 g/t of MDI used. Dispersion modeling predicts that concentrations at the fenceline or beyond are very low for typical releases. Laboratory studies show that TDI (and by analogy MDI) does not react with water in the gas phase at a significant rate. The primary degradation reaction of these aromatic diisocyanates in the atmosphere is expected to be oxidation by OH radicals with an estimated half-life of one day. Laboratory studies also show that this reaction is not expected to result in increased ground-level ozone accumulation.

  6. Real-time computing of the environmental consequences of an atmospheric accidental release of radioactive material: user's point of view

    International Nuclear Information System (INIS)

    Boeri, G.; Caracciolo, R.; Dickerson, M.

    1985-07-01

    All calculations of the consequences of an atmospheric release must start with atmospheric dispersion calculations. Time factors make external and inhalation dose estimates of immediate concern closely followed by ground contamination of land, pastures and onch agricultural crops. In general, the difficulties in modeling the source term and atmospheric transport and diffusion account for most of the error in calculating the dose to man. Thus, sophisticated treatment of the dose part of the calculating is not usually justified, though the relative distribution of dose in individual organs may be needed for correct decision marking. This paper emphasizes the atmospheric transport and diffusion part of the dose estimate and relates how this calculation can be used to estimate dose. 12 refs

  7. Assessment of impact of a severe accident at nuclear power plant of Angra dos Reis with release of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Aguiar, Andre Silva de

    2015-01-01

    This study had as purpose the assess the impact of a severe accident, and also analyze the dispersion of 131 I in the atmosphere, so that, through concentrating and inhaling dose of the plume, were possible to verify if the results are in accordance with the indicated data by the Plan of Emergency of the CNAAA regarding the Impact Zone and Control. This exercise was performed with the aid of an atmospheric model and a dispersion where to atmospheric modeling we used the data coupling WRF / CALMET and of dispersion, CALPUFF. The suggested accident consists of a Station Blackout at Nuclear Power of Angra (Unit 1), where through the total core involvement, will release 100% of the 131 I to the atmosphere. The value of the total activity in the nucleus to this radionuclide is 7.44 x 1017 Bq, that is relative on the sixth day of burning. This activity will be released through the chimney at a rate in Bq/s in the scenario of 12, 24, 48 and 72 hours of release. Applying the model in the proposed scenario, it is verified that the plume has concentrations of the order of 1020 Bq/m³ and dose of about 108 Sv whose value is beyond of the presented by Eletronuclear in your current emergency plan. (author)

  8. Overview of the National Atmospheric Release Advisory Center's urban research and development activities

    International Nuclear Information System (INIS)

    Lundquist, J K; Sugiyama, G A; Nasstrom, J

    2007-01-01

    This presentation describes the tools and services provided by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL) for modeling the impacts of airborne hazardous materials. NARAC provides atmospheric plume modeling tools and services for chemical, biological, radiological, and nuclear airborne hazards. NARAC can simulate downwind effects from a variety of scenarios, including fires, industrial and transportation accidents, radiation dispersal device explosions, hazardous material spills, sprayers, nuclear power plant accidents, and nuclear detonations. NARAC collaborates on radiological dispersion source terms and effects models with Sandia National Laboratories and the U.S. Nuclear Regulatory Commission. NARAC was designated the interim provider of capabilities for the Department of Homeland Security's Interagency Modeling and Atmospheric Assessment Center by the Homeland Security Council in April 2004. The NARAC suite of software tools include simple stand-alone, local-scale plume modeling tools for end-user's computers, and Web- and Internet-based software to access advanced modeling tools and expert analyses from the national center at LLNL. Initial automated, 3-D predictions of plume exposure limits and protective action guidelines for emergency responders and managers are available from the center in 5-10 minutes. These can be followed immediately by quality-assured, refined analyses by 24 x 7 on-duty or on-call NARAC staff. NARAC continues to refine calculations using updated on-scene information, including measurements, until all airborne releases have stopped and the hazardous threats are mapped and impacts assessed. Model predictions include the 3-D spatial and time-varying effects of weather, land use, and terrain, on scales from the local to regional to global. Real-time meteorological data and forecasts are provided by redundant communications links to the U.S. National Oceanic and Atmospheric

  9. Utilization of the atmospheric release advisory capability (ARAC) services during and after the Three Mile Island accident

    International Nuclear Information System (INIS)

    Knox, J.B.; Dickerson, M.H.; Greenly, G.D.; Gudiksen, P.H.; Sullivan, T.J.

    1980-01-01

    At 0820 PST on 28 March 1979, the Department of Energy's Emergency Operations Center advised the Atmospheric Release Advisory Capability (ARAC) that the Three Mile Island nuclear power plant in Harrisburg, Pennsylvania, had experienced an accident some four hours earlier, resulting in the atmospheric release of xenon-133 and krypton-88. This report describes ARAC's response to the Three Mile Island accident, including the role ARAC played throughout the 20 days that real-time assessments were made available to the Department of Energy on-scene commander. It also describes the follow-up population-dose calculations performed for the President's Commission on Three Mile Island. At the request of the Nuclear Regulatory Commission, a questionnaire addressing the usefulness of ARAC products during the accident was sent to ARAC-product users. A summary of the findings from this questionnaire, along with recommendations for improving ARAC service, is also presented. The accident at Mississauga, Ontario, Canada, is discussed in the context of a well-planned emergency response by local and Federal officials

  10. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Directory of Open Access Journals (Sweden)

    S. Ars

    2017-12-01

    Full Text Available This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping

  11. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Science.gov (United States)

    Ars, Sébastien; Broquet, Grégoire; Yver Kwok, Camille; Roustan, Yelva; Wu, Lin; Arzoumanian, Emmanuel; Bousquet, Philippe

    2017-12-01

    This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances

  12. 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

  13. Early and late histamine release induced by albumin, hetastarch and polygeline: some unexpected findings.

    Science.gov (United States)

    Celik, I; Duda, D; Stinner, B; Kimura, K; Gajek, H; Lorenz, W

    2003-10-01

    The perioperative use of colloidal plasma substitutes is still under discussion. We therefore conducted a prospective randomised study with three commonly used plasma substitutes to examine their histamine releasing effects in 21 volunteers. MATERIAL OR SUBJETS: 21 male volunteers were enrolled in this prospective, randomised, controlled clinical study. Endpoints were the incidence of early and late histamine release and the time course of the release kinetics. Normovolemic hemodilution technique was used with hydroxyethyl starch (n = 6), human albumin (n = 6) and polygeline (n = 9). Measurement and observation period was 240 min after the start of the plasma substitute infusion. Heart rate, blood pressure, SaO(2), clinical symptoms/signs and plasma histamine were measured during the observation period. The incidence of histamine release over the whole observation period in all three groups was 100%. Histamine release occurred frequently in all three groups until 30 min (50%-78%) and up to 240 min (late release reaction: 67%-83%) after the start of infusion. Surprisingly even hydroxyethyl starch, which is regarded as a generally safe and effective plasma substitute, caused high incidences of late histamine release (67%). Histamine release is a well known side effect of polygeline and - to a lesser extent - also of albumin, but was a novel finding for hydroxyethyl starch. We demonstrated for the first time histamine releasing effects of hydroxyethyl starch over a long period of time after administration. This perioperatively and for intensive care possibly relevant finding should make clinicians aware of late side effects not yet connected with the clinical use of these colloidal plasma substitutes.

  14. Overview of the National Atmospheric Release Advisory Center's Urban Research and Development Activities

    Science.gov (United States)

    Lundquist, J. K.; Sugiyama, G.; Nasstrom, J.

    2007-12-01

    This presentation describes the tools and services provided by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL) for modeling the impacts of airborne hazardous materials. NARAC provides atmospheric plume modeling tools and services for chemical, biological, radiological, and nuclear airborne hazards. NARAC can simulate downwind effects from a variety of scenarios, including fires, industrial and transportation accidents, radiation dispersal device explosions, hazardous material spills, sprayers, nuclear power plant accidents, and nuclear detonations. NARAC collaborates on radiological dispersion source terms and effects models with Sandia National Laboratories and the U.S. Nuclear Regulatory Commission. NARAC was designated the interim provider of capabilities for the Department of Homeland Security's Interagency Modeling and Atmospheric Assessment Center by the Homeland Security Council in April 2004. The NARAC suite of software tools include simple stand-alone, local-scale plume modeling tools for end-user's computers, and Web- and Internet-based software to access advanced modeling tools and expert analyses from the national center at LLNL. Initial automated, 3-D predictions of plume exposure limits and protective action guidelines for emergency responders and managers are available from the center in 5-10 minutes. These can be followed immediately by quality-assured, refined analyses by 24 x 7 on-duty or on-call NARAC staff. NARAC continues to refine calculations using updated on-scene information, including measurements, until all airborne releases have stopped and the hazardous threats are mapped and impacts assessed. Model predictions include the 3-D spatial and time-varying effects of weather, land use, and terrain, on scales from the local to regional to global. Real-time meteorological data and forecasts are provided by redundant communications links to the U.S. National Oceanic and Atmospheric

  15. TRADOS - an air trajectory dose model for long range transport of radioactive release to the atmosphere

    International Nuclear Information System (INIS)

    Rossi, J.; Valkama, I.

    1985-01-01

    A model for estimating radiation doses resulting from long range atmospheric transport of released radionuclides in accidents is precented. The model (TRADOS) is able to treat changing diffusion conditions. For example the plume can be exposed to temporary rain, changes in turbulence and mixing depth. This can result in considerable changes in individual doses. The method is applied to an example trajectory and the doses caused by a serious reactor accident are calculated

  16. A guide to TIRION 4 - a computer code for calculating the consequences of releasing radioactive material to the atmosphere

    International Nuclear Information System (INIS)

    Fryer, L.S.

    1978-12-01

    TIRION 4 is the most recent program in a series designed to calculate the consequences of releasing radioactive material to the atmosphere. A brief description of the models used in the program and full details of the various control cards necessary to run TIRION 4 are given. (author)

  17. Atmospheric tritium 1968-1984. Tritium Laboratory data report No. 14

    International Nuclear Information System (INIS)

    Oestlund, H.G.; Mason, A.S.

    1985-04-01

    Tritium in the form of water, HTO, from the atmospheric testing of nuclear devices in the 60s has now mainly disappeared from the atmosphere and entered the ocean. The additions of such tritium from Chinese and French tests in the 70s were observed but did not make a big impression on the diminishing inventory of atmospheric HTO. Tritium in elemental form, HT, went through a maximum in the mid 70s, apparently primarily as a results of some underground testing of large nuclear devices and releases from civilian and military nuclear industry. The mid 70s maximum was 1.3 kg of tritium in this form, and in 1984 0.5 kg remain. The disappearance is slower than the decay rate of tritium, so sources must still have been present during this time. The global distribution shows, not unexpectedly, smaller inventory in the Southern Hemisphere across the equator and thus southward transport of HT. The chemical lifetime of hydrogen gas in the atmosphere, assuming the elemental tritium being in the form of HT, not T 2 , has been estimated between 6 and 10 years. It is to be expected that increasing activity of nuclear fuel reprocessing would in the near future again increase the global tritium gas inventory. Tritium in the form of light hydrocarbons, primarily methane, has also been measured, and in this form a quantity of 200 g of tritium resided in the global atmosphere 1956 to 1976. By 1982 it had decreased to 50 g. 25 refs., 5 figs., 11 tabs

  18. Effects of building structures on radiation doses from routine releases of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1978-01-01

    Realistic assessments of radiation doses to the population from routine releases of radionuclides to the atmosphere require consideration of man's largely indoor environment. The effect of a building structure on radiation doses is described quantitatively by a dose reduction factor, which is the ratio of the dose to a reference individual inside a structure to the corresponding dose with no structure present. We have implemented models to estimate dose reduction factors for internal dose from inhaled radionuclides and for external photon dose from airborne and surface-deposited radionuclides. The models are particularly useful in radiological assessment applications, since dose reduction factors may readily be estimated for arbitrary mixtures and concentrations of radionuclides in the atmosphere and on the ground. The model for inhalation dose reduction factors accounts for radioactive decay, air ventilation into and out of the structure, and deposition of radionuclides on inside surfaces of the structure. External dose reduction factors are estimated using the point-kernel integration method including consideration of buildup in air and the walls of the building. The potential importance of deposition of radionuclides on inside surfaces of a structure on both inhalation and external dose reduction factors has been demonstrated. Model formulation and the assumptions used in the calculations are discussed. Results of model-parameter sensitivity studies and estimates of dose reduction factors for radionuclides occurring in routine releases from an LWR fuel reprocessing plant are presented. (author)

  19. Reductive Alkaline Release of N-Glycans Generates a Variety of Unexpected, Useful Products.

    Science.gov (United States)

    Figl, Rudolf; Altmann, Friedrich

    2018-02-01

    Release of O-glycans by reductive β-elimination has become routine in many glyco-analytical laboratories and concomitant release of N-glycans has repeatedly been observed. Revisiting this somewhat forgotten mode of N-glycan release revealed that all kinds of N-glycans including oligomannosidic and complex-type N-glycans from plants with 3-linked fucose and from mammals with or without 6-linked fucose and with sialic acid could be recovered. However, the mass spectra of the obtained products revealed very surprising facts. Even after 16 h incubation in 1 M sodium borohydride, a large part of the glycans occurred in reducing form. Moreover, about one third emerged in the form of the stable amino-functionalized 1-amino-1-deoxy-glycitol. When avoiding acidic conditions, considerable amounts of glycosylamine were observed. In addition, a compound with a reduced asparagine and de-N-acetylation products, in particular of sialylated glycans, was seen. The relative yields of the products reducing glycosylamine, reducing N-glycan, 1-amino-1-deoxy-glycitol or glycitol could be controlled by the release conditions, foremost by temperature and borohydride concentration. Thus, chemical release of N-glycans constitutes a cost-saving alternative to enzymatic hydrolysis for the preparation of precursors for the production of reference compounds for various formats of N-glycan analysis. Moreover, it allows to obtain a stable amino-functionalized glycan derivative, which can be employed to construct glycan arrays or affinity matrices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The stability of CaS in circulating fluidized bed boiler residue and the possible release of H2S gas to the atmosphere

    International Nuclear Information System (INIS)

    Mattisson, T.; Lyngfelt, A.

    1995-01-01

    During the combustion of coal, SO 2 is released to the atmosphere. Because of environmental concerns with acid rain, the capture of SO 2 is an important issue. In fluidized bed combustion SO 2 is captured in-situ by limestone or dolomite to form CaSO 4 . This product is stable and can be disposed of or reused as gypsum. In order to capture the sulphur as CaSO 4 oxidizing conditions are necessary. In a fluidized bed boiler (FBB) CaS may form in regions with reducing conditions, and FBB ashes sampled under irregular operating conditions may contain as much as 50 % of the captured sulphur as CaS. The stability of CaS in a landfill environment is thus very important. It is possible that the sulphide decomposes in the presence of moisture or runoff leachate with the subsequent release of H 2 S gas. This re-release of captured sulphur could have a substantial effect on the overall sulphur capture efficiency, with more sulphur released to the atmosphere than previously thought. In this study the stability of CaS in bed ashes from a 12 MW circulating FBB combusting coal has been investigated, with focus on the release of H 2 S gas. (orig.)

  1. Non-Darwinian evolution for the source detection of atmospheric releases

    Science.gov (United States)

    Cervone, Guido; Franzese, Pasquale

    2011-08-01

    A non-Darwinian evolutionary algorithm is presented as search engine to identify the characteristics of a source of atmospheric pollutants, given a set of concentration measurements. The algorithm drives iteratively a forward dispersion model from tentative sources toward the real source. The solutions of non-Darwinian evolution processes are not generated through pseudo-random operators, unlike traditional evolutionary algorithms, but through a reasoning process based on machine learning rule generation and instantiation. The new algorithm is tested with both a synthetic case and with the Prairie Grass field experiment. To further test the capabilities of the algorithm to work in real-world scenarios, the source identification of all Prairie Grass releases was performed with a decreasing number of sensor measurements, and a relationship is found between the precision of the solution, the number of sensors available, and the levels of concentration measured by the sensors. The proposed methodology can be used for a variety of optimization problems, and is particularly suited for problems where the operations needed for evaluating new candidate solutions are computationally expensive.

  2. PABLM, Doses from Radioactive Releases to Atmosphere and Food Chain

    International Nuclear Information System (INIS)

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

    1983-01-01

    1 - Description of problem or function: PABLM calculates internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. 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 after the releases have ended. Radioactive decay is considered during the release, after deposition, and during holdup of food after harvest. The radiation dose models consider exposure to radionuclides deposited on the ground or crops from contaminated air or irrigation water, radionuclides in contaminated drinking water, aquatic foods raised in contaminated water, and radionuclides in bodies of water and sediments where people might fish, boat, or swim. For vegetation, the radiation dose model considers both direct deposition and uptake through roots. Doses may be calculated for either a maximum-exposed individual or for a population group. The program is designed to calculate accumulated radiation doses from the chronic ingestion of food products that contain radionuclides and doses from the external exposure to radionuclides in the environment. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. 2 - Method of solution: A chain decay scheme including branching for transitions to and from isomeric states is used for radioactive decay. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radio- logical Protection (ICRP) for body burdens and the maximum possible concentration (MPC) for each radionuclide. These doses are calculated as a function of radionuclide concentration in food products, ingestion rates, and a radionuclide-specific dose- commitment factor. Radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption

  3. Fluxes of Ethanol Between the Atmosphere and Oceanic Surface Waters; Implications for the Fate of Biofuel Ethanol Released into the Environment

    Science.gov (United States)

    Avery, G. B., Jr.; Shimizu, M. S.; Willey, J. D.; Mead, R. N.; Skrabal, S. A.; Kieber, R. J.; Lathrop, T. E.; Felix, J. D. D.

    2017-12-01

    The use of ethanol as a transportation fuel has increased significantly during the past decade in the US. Some ethanol escapes the combustion process in internal combustion engines resulting in its release to the atmosphere. Ethanol can be oxidized photochemically to acetaldehyde and then converted to peroxyacetyl nitrate contributing to air pollution. Therefore it is important to determine the fate ethanol released to the atmosphere. Because of its high water solubility the oceans may act as a sink for ethanol depending on its state of saturation with respect to the gas phase. The purpose of the current study was to determine the relative saturation of oceanic surface waters by making simultaneous measurements of gas phase and surface water concentrations. Data were obtained from four separate cruises ranging from estuarine to open ocean locations in the coast of North Carolina, USA. The majority of estuarine sites were under saturated in ethanol with respect to the gas phase (11-50% saturated) representing a potential sink. Coastal surface waters tended to be supersaturated (135 - 317%) representing a net flux of ethanol to the atmosphere. Open ocean samples were generally at saturation or slightly below saturation (76-99%) indicating equilibrium between the gas and aqueous phases. The results of this study underscore to variable role the oceans play in mitigating the increases in atmospheric ethanol from increased biofuel usage and their impact on air quality.

  4. Effects of indoor residence on radiation doses from routine releases of radionuclides to the atmosphere

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1980-01-01

    Dose reduction factors from indoor residence during routine releases of radionuclides to the atmosphere were studied using models that are suitable for application to arbitrary source terms. Dose reduction factors for internal exposure to inhaled radionuclides account for air ventilation and deposition on inside building surfaces. Estimated internal dose reduction factors are approx. 0.2 to 0.8 for particulates and 0.07 to 0.4 for radioiodine. Dose reduction factors for external photon exposure from airborne and surface-deposited sources are based on the point-kernel integration method. Values for source terms from a fuel reprocessing plant and a hypothetical reactor accident are within a factor of 2 of the value 0.5 adopted by the US Nuclear Regulatory Commission (NRC) for population dose assessments. For the release at Three Mile Island nuclear station, however, the external dose reduction factor may be an order of magnitude less than the value adopted by the NRC

  5. HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories)

    International Nuclear Information System (INIS)

    Kim, S.B.; Bredlaw, M.; Korolevych, V.Y.

    2012-01-01

    Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0–5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Highlights: ► At the historical HT release site, HTO and OBT activity concentrations in soil depths were investigated. ► Most organically bound tritium exists in the top layer of the soil. ► The results indicated that OBT activity concentrations can be reflective of historical tritium releases into the environment.

  6. Application of the HGSYSTEM/UF6 model to simulate atmospheric dispersion of UF6 releases from uranium enrichment plants

    International Nuclear Information System (INIS)

    Goode, W.D. Jr.; Bloom, S.G.; Keith, K.D. Jr.

    1995-01-01

    Uranium hexafluoride is a dense, reactive gas used in Gaseous Diffusion Plants (GDPs) to make uranium enriched in the 235 U isotope. Large quantities of UF 6 exist at the GDPs in the form of in-process gas and as a solid in storage cylinders; smaller amounts exist as hot liquid during transfer operations. If liquid UF 6 is released to the environment, it immediately flashes to a solid and a dense gas that reacts rapidly with water vapor in the air to form solid particles of uranyl fluoride and hydrogen fluoride gas. Preliminary analyses were done on various accidental release scenarios to determine which scenarios must be considered in the safety analyses for the GDPS. These scenarios included gas releases due to failure of process equipment and liquid/gas releases resulting from a breach of transfer piping from a cylinder. A major goal of the calculations was to estimate the response time for mitigating actions in order to limit potential off-site consequences of these postulated releases. The HGSYSTEM/UF 6 code was used to assess the consequences of these release scenarios. Inputs were developed from release calculations which included two-phase, choked flow followed by expansion to atmospheric pressure. Adjustments were made to account for variable release rates and multiple release points. Superpositioning of outputs and adjustments for exposure time were required to evaluate consequences based on health effects due to exposures to uranium and HF at a specific location

  7. Dams release methane even in temperate zoned

    International Nuclear Information System (INIS)

    Lemarchand, F.

    2010-01-01

    The Wohlen lake (near Bern) is a retaining dam built 90 years ago that has undergone a campaign to measure the quantity of methane released. The campaign lasted 1 year and the result was unexpected: 0.15 g/m 2 *day which one of the highest release rates in temperate zones. This result is all the more stunning since water stays only 2 days in average in the reservoir and that the drowned area is not important. In fact the river Aar that feeds the lake is loaded with organic matter coming from humane activities: agriculture and 3 sewage plants. This organic matter decays in the lake releasing methane. (A.C.)

  8. Evaluation of three atmospheric dispersion models using tracer release experiment data

    International Nuclear Information System (INIS)

    Daoo, V.J.; Oza, R.B.; Pandit, G.G.; Sadasivan, S.; Venkat Raj, V.

    2004-01-01

    Performance of three atmospheric dispersion models viz: (1) Gaussian Plume Model (GPM), (2) Equi-Distance PUFF Model (EDPUFFM) and (3) Particle Trajectory Model (PTM) is evaluated using field data collected from a tracer (SF 6 ) release experiment. The experiment was conducted within the campus of the Bhabha Atomic Research Centre (BARC), located at Trombay, Mumbai, India. The three models used are currently in operation at the BARC. The first one is a standard, well-documented empirical model while the other two models have been developed at the Bhabha Atomic Research Centre. The PTM is a numerical model while the EDPUFFM is a hybrid model combining both the numerical and analytical techniques. The procedure for evaluation is as per the recommendations of 1980 AMS (American Meteorological Society) workshop on atmospheric dispersion models performance evaluation. In addition, linear regression analysis has also been carried out. The regression analysis reveals that on an average, the EDPUFFM and the GPM predictions are higher by a factor of about 1.5 while the PTM predictions are lower by a factor of about 4. Comparison of various performance measures reveals that the performance of the EDPUFFM is marginally better than that of the GPM while the PTM performance is comparatively poor. The uncertainty factors obtained in this study, especially for higher concentration range ( > 100 ppt) are similar to those obtained in other validation study carried out elsewhere to validate the GPM predictions. However, for lower concentration range and for the conditions after the source is switched off, all the three models perform poorly in predicting the concentration. (author)

  9. GEWEX SRB Shortwave Release 4

    Science.gov (United States)

    Cox, S. J.; Stackhouse, P. W., Jr.; Mikovitz, J. C.; Zhang, T.

    2017-12-01

    The NASA/GEWEX Surface Radiation Budget (SRB) project produces shortwave and longwave surface and top of atmosphere radiative fluxes for the 1983-near present time period. Spatial resolution is 1 degree. The new Release 4 uses the newly processed ISCCP HXS product as its primary input for cloud and radiance data. The ninefold increase in pixel number compared to the previous ISCCP DX allows finer gradations in cloud fraction in each grid box. It will also allow higher spatial resolutions (0.5 degree) in future releases. In addition to the input data improvements, several important algorithm improvements have been made since Release 3. These include recalculated atmospheric transmissivities and reflectivities yielding a less transmissive atmosphere. The calculations also include variable aerosol composition, allowing for the use of a detailed aerosol history from the Max Planck Institut Aerosol Climatology (MAC). Ocean albedo and snow/ice albedo are also improved from Release 3. Total solar irradiance is now variable, averaging 1361 Wm-2. Water vapor is taken from ISCCP's nnHIRS product. Results from GSW Release 4 are presented and analyzed. Early comparison to surface measurements show improved agreement.

  10. GPU-based parallel computing in real-time modeling of atmospheric transport and diffusion of radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcelo C. dos; Pereira, Claudio M.N.A.; Schirru, Roberto; Pinheiro, André, E-mail: jovitamarcelo@gmail.com, E-mail: cmnap@ien.gov.br, E-mail: schirru@lmp.ufrj.br, E-mail: apinheiro99@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    Atmospheric radionuclide dispersion systems (ARDS) are essential mechanisms to predict the consequences of unexpected radioactive releases from nuclear power plants. Considering, that during an eventuality of an accident with a radioactive material release, an accurate forecast is vital to guide the evacuation plan of the possible affected areas. However, in order to predict the dispersion of the radioactive material and its impact on the environment, the model must process information about source term (radioactive materials released, activities and location), weather condition (wind, humidity and precipitation) and geographical characteristics (topography). Furthermore, ARDS is basically composed of 4 main modules: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The Wind Field and Plume Dispersion modules are the ones that require a high computational performance to achieve accurate results within an acceptable time. Taking this into account, this work focuses on the development of a GPU-based parallel Plume Dispersion module, focusing on the radionuclide transport and diffusion calculations, which use a given wind field and a released source term as parameters. The program is being developed using the C ++ programming language, allied with CUDA libraries. In comparative case study between a parallel and sequential version of the slower function of the Plume Dispersion module, a speedup of 11.63 times could be observed. (author)

  11. GPU-based parallel computing in real-time modeling of atmospheric transport and diffusion of radioactive material

    International Nuclear Information System (INIS)

    Santos, Marcelo C. dos; Pereira, Claudio M.N.A.; Schirru, Roberto; Pinheiro, André; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    Atmospheric radionuclide dispersion systems (ARDS) are essential mechanisms to predict the consequences of unexpected radioactive releases from nuclear power plants. Considering, that during an eventuality of an accident with a radioactive material release, an accurate forecast is vital to guide the evacuation plan of the possible affected areas. However, in order to predict the dispersion of the radioactive material and its impact on the environment, the model must process information about source term (radioactive materials released, activities and location), weather condition (wind, humidity and precipitation) and geographical characteristics (topography). Furthermore, ARDS is basically composed of 4 main modules: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The Wind Field and Plume Dispersion modules are the ones that require a high computational performance to achieve accurate results within an acceptable time. Taking this into account, this work focuses on the development of a GPU-based parallel Plume Dispersion module, focusing on the radionuclide transport and diffusion calculations, which use a given wind field and a released source term as parameters. The program is being developed using the C ++ programming language, allied with CUDA libraries. In comparative case study between a parallel and sequential version of the slower function of the Plume Dispersion module, a speedup of 11.63 times could be observed. (author)

  12. Comparison of the COMRADEX-IV and AIRDOS-EPA methodologies for estimating the radiation dose to man from radionuclide releases to the atmosphere

    International Nuclear Information System (INIS)

    Miller, C.W.; Hoffman, F.O.; Dunning, D.E. Jr.

    1981-01-01

    This report presents a comparison between two computerized methodologies for estimating the radiation dose to man from radionuclide releases to the atmosphere. The COMRADEX-IV code was designed to provide a means of assessing potential radiological consequences from postulated power reactor accidents. The AIRDOS-EPA code was developed primarily to assess routine radionuclide releases from nuclear facilities. Although a number of different calculations are performed by these codes, three calculations are in common - atmospheric dispersion, estimation of internal dose from inhalation, and estimation of external dose from immersion in air containing gamma emitting radionuclides. The models used in these calculations were examined and found, in general, to be the same. Most differences in the doses calculated by the two codes are due to differences in values chosen for input parameters and not due to model differences. A sample problem is presented for illustration

  13. Plutonium in the environment: key factors related to impact assessment in case of an accidental atmospheric release

    Energy Technology Data Exchange (ETDEWEB)

    Guetat, P. [CEA Valduc, 21 - Is-sur-Tille (France); Moulin, V.; Reiller, P. [CEA Saclay, 91 (FR)] (and others)

    2009-07-01

    This paper deals with plutonium and key factors related to impact assessment. It is based on recent work performed by CEA which summarize the main features of plutonium behaviour from sources inside installations to the environment and man, and to report current knowledge on the different parameters used in models for environmental and radiological impact assessment. These key factors are illustrated through a case study based on an accidental atmospheric release of Pu in a nuclear facility. (orig.)

  14. Maximum permissible continuous release rates of phosphorus-32 and sulphur-35 to atmosphere in a milk producing area

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, P M

    1963-01-01

    A method is given for calculating, for design purposes, the maximum permissible continuous release rates of phosphorus-32 and sulphur-35 to atmosphere with respect to milk contamination. In the absence of authoritative advice from the Medical Research Council, provisional working levels for the concentration of phosphorus-32 and sulphur-35 in milk are derived, and details are given of the agricultural assumptions involved in the calculation of the relationship between the amount of the nuclide deposited on grassland and that to be found in milk. The agricultural and meteorological conditions assumed are applicable as an annual average to England and Wales. The results (in mc/day) for phosphorus-32 and sulphur-35 for a number of stack heights and distances are shown graphically; typical values, quoted in a table, include 20 mc/day of phosphorus-32 and 30 mc/day of sulfur-35 as the maximum permissible continuous release rates with respect to ground level releases at a distance of 200 metres from pastureland.

  15. Unexpected dependence on pH of NO release from Paracoccus pantotrophus cytochrome cd1

    International Nuclear Information System (INIS)

    Sam, Katharine A.; Tolland, John D.; Fairhurst, Shirley A.; Higham, Christopher W.; Lowe, David J.; Thorneley, Roger N.F.; Allen, James W.A.; Ferguson, Stuart J.

    2008-01-01

    A previous study of nitrite reduction by Paracoccus pantotrophus cytochrome cd 1 at pH 7.0 identified early reaction intermediates. The c-heme rapidly oxidised and nitrite was reduced to NO at the d 1 -heme. A slower equilibration of electrons followed, forming a stable complex assigned as 55% cFe(III)d 1 Fe(II)-NO and 45% cFe(II)d 1 Fe(II)-NO + . No catalytically competent NO release was observed. Here we show that at pH 6.0, a significant proportion of the enzyme undergoes turnover and releases NO. An early intermediate, which was previously overlooked, is also identified; enzyme immediately following product release is a candidate. However, even at pH 6.0 a considerable fraction of the enzyme remains bound to NO so another component is required for full product release. The kinetically stable product formed at the end of the reaction differs significantly at pH 6.0 and 7.0, as does its rate of formation; thus the reaction is critically dependent on pH

  16. Fission-product release during accidents

    International Nuclear Information System (INIS)

    Hunt, C.E.L.; Cox, D.S.

    1991-09-01

    One of the aims when managing a reactor accident is to minimize the release of radioactive fission products. Release is dependent not only on the temperature, but also on the partial pressure of oxygen. Strongly oxidizing atmospheres, such as those that occurred during the Chernobyl accident, released semi-volatile elements like ruthenium, which has volatile oxides. At low temperatures, UO 2 oxidization to U 3 O 8 can result in extensive breakup of the fuel, resulting in the release of non-volatile fission products as aerosols. Under less oxidizing conditions, when hydrogen accumulates from the zirconium-water reaction, the resulting low oxygen partial pressure can significantly reduce these reactions. At TMI-2, only the noble gases and volatile fission products were released in significant quantities. A knowledge of the effect of atmosphere as well as temperature on the release of fission products from damaged reactor cores is therefore a useful, if not necessary, component of information required for accident management

  17. The Risoe model for calculating the consequences of the release of radioactive material to the atmosphere

    International Nuclear Information System (INIS)

    Thykier-Nielsen, S.

    1980-07-01

    A brief description is given of the model used at Risoe for calculating the consequences of releases of radioactive material to the atmosphere. The model is based on the Gaussian plume model, and it provides possibilities for calculation of: doses to individuals, collective doses, contamination of the ground, probability distribution of doses, and the consequences of doses for give dose-risk relationships. The model is implemented as a computer program PLUCON2, written in ALGOL for the Burroughs B6700 computer at Risoe. A short description of PLUCON2 is given. (author)

  18. Unexpected high plasma cobalamin

    DEFF Research Database (Denmark)

    Arendt, Johan F B; Nexo, Ebba

    2013-01-01

    It is well-established that more than 8% of patients examined for vitamin B12 deficiency unexpectedly have increased plasma levels of the vitamin, but so far there are no guidelines for the clinical interpretation of such findings. In this review, we summarise known associations between high plasma...... cobalamin binding proteins, transcobalamin and haptocorrin. Based on current knowledge, we suggest a strategy for the clinical interpretation of unexpected high plasma cobalamin. Since a number of the associated diseases are critical and life-threatening, the strategy promotes the concept of 'think...

  19. National atmospheric release advisory center (NARAC) tools and services for emergency management

    International Nuclear Information System (INIS)

    Nasstrom, J.

    2003-01-01

    Full text: This paper describes recent scientific and technological advances in the National Atmospheric Release Advisory Center (NARAC) that aid emergency management. The U.S. Department of Energy's NARAC system provides tools and services that help map the probable spread of hazardous material accidentally or intentionally released into the atmosphere. Located at Lawrence Livermore National Laboratory, NARAC is a national support and resource center for planning, real-time assessment and detailed studies of incidents involving a wide variety of hazards, including nuclear, radiological, chemical, or biological emissions. In recent years, the DOE National Nuclear Security Agency (NNSA) Office of Emergency Response and Chemical and Biological National Security Program (CBNP) have supported major upgrades and modernization of NARAC that have advanced the accuracy and utility of NARAC products for emergency planning and management. A new NARAC central modeling system, which became operational in the year 2000, has provided a higher-resolution suite of diagnostic and prognostic meteorological models, and a Lagrangian particle dispersion model, for producing predictions of air concentration, ground deposition, and dose. The 3-D meteorological data assimilation model, ADAPT, and Lagrangian particle dispersion model, LODI, allow the simulation of mean wind advection, turbulent diffusion, radioactive decay and production, bio-agent degradation, first-order chemical reactions, wet deposition, gravitational settling, dry deposition, and buoyant/momentum plume rise. The functions performed by this system have been fully automated to minimized response time for emergencies. An in-house version of the Naval Research Laboratory's COAMPS numerical weather prediction model is used to provide mesoscale forecasts. The final plume predictions are plotted with key geographical information (including estimates of the counts of affected population), and with applicable U

  20. Two standards - CSA-N288.1 and USNRC regulatory guides 1.109, 1.111 for chronic atmospheric releases from nuclear facilities - compared

    International Nuclear Information System (INIS)

    Peterson, S-R.

    1997-05-01

    Although the Canadian Standards Association's 'Guidelines for Calculating Derived Release Limits for Radioactive Material in Airborne and Liquid Effluents for Normal Operation of Nuclear Facilities', CSA-N288.1-M87 (CSA 1987) can be used to license CANDU (CANadian Deuterium Uranium) reactors sold off-shore, in practice purchasers may wish to use the United States Regulatory Guides (RG) 1.109 (United States Nuclear Regulatory Commission 1977a) and 1.111 (USNRC 1977b) to calculate doses from routine atmospheric releases to members of a critical group. When differences in dose predictions are found between the two standards, CSA-N288.1 comes under attack. This paper explains the differences between the two models. The two atmospheric dispersion models were compared for a ground level release and an elevated release such as from CANDU 6. For a ground level release, CSA's dilution factors were slightly more than half of RG's. For the elevated release, following recommendations in each guide, CSA's dilution coefficient is higher than RG's within 1000 m of the stack and only slightly lower farther away. All differences can be accounted for by different mathematical formulations and assumptions about height at which wind speed is measured. Ingestion, inhalation, immersion and external doses predicted by the two models were compared for unit release (Bq s -1 ) and for realistic source terms of a suite of 33 radionuclides commonly released from both CANDUs and Pressurized Water Reactors (PWRs). To demonstrate real differences in the models, ingestion doses for the two models were compared using the CSA diet in both models and CSA predictions were recalculated to account for decay which occurs between harvest and ingestion in RG. Once all assumptions are equalized, there is very little difference in dose predictions of the two models that cannot be explained by different parameter values. Both models have outdated dose conversion factors, and the use of improved numbers will

  1. A comparison of alternative methods of calculating complementary cumulative distribution functions of health effects following an atmospheric radioactive release

    International Nuclear Information System (INIS)

    Ponting, A.C.; Nair, S.

    1984-04-01

    A concept extensively used in studying the consequences of accidental atmospheric radioactive releases is that of the Complementary Cumulative Distribution Function, CCDF. Various methods of calculating CCDFs have been developed with particular applications in putting degraded core accidents in perspective and in identifying release sequences leading to high risks. This note compares three methods with specific reference to their accuracy and computational efficiency. For two of the methods (that used in the US Reactor Safety Study code CRAC2 and extended version of that method), the effects of varying the sector width and considering site-specific population distributions have been determined. For the third method it is only necessary to consider the effects of site-specific population distributions. (author)

  2. Deciduous birch canopy as unexpected contributor to stand level atmospheric reactivity in boreal forests

    Science.gov (United States)

    Bäck, Jaana; Taipale, Ditte; Aalto, Juho

    2017-04-01

    In boreal forests, deciduous trees such as birches may in future climate become more abundant due to their large biomass production capacity, relatively good resource use ability and large acclimation potential to elevated CO2 levels and warmer climate. Increase in birch abundance may lead to unpredicted consequences in atmospheric composition. Currently it is acknowledged that conifers such as Scots pine and Norway spruce are important sources for volatile organic compounds (VOCs), especially monoterpenes, throughout the year, although the strong temperature relationships implies that emissions are highest in summertime. However, the dynamics of the deciduous birch foliage VOC emissions and their relationship with environmental drivers during the development, maturation and senescence of foliage has not been well analyzed. Long-term measurements of birch, which are unfortunately very sparse, can provide very useful information for the development of biosphere-atmosphere models that simulate boreal and subarctic forested areas where birch is often a sub-canopy species, occurs as a mixture among conifers or forms even pure stands in the higher latitudes. We measured the branch level VOC emissions from a mature Silver birch with proton transfer reaction mass spectrometer during 2014 and 2015 at the SMEAR II station (Station for Measuring Ecosystem-Atmosphere Relations), southern Finland. Our results showed that the Silver birch foliage is a huge source for both short-chained volatiles such as methanol, acetaldehyde and acetone, as well as for monoterpenes. The mean emission rates from birch leaves were 5 to 10 times higher than the corresponding emissions from Scots pine shoots. We compared several semi-empirical model approaches for determining the birch foliage monoterpene standardized emission potentials, and utilized the continuous emission measurements from the two growing seasons for development of a novel algorithm which accounts for the leaf development and

  3. Unexpected uncertainty, volatility and decision-making

    Directory of Open Access Journals (Sweden)

    Amy Rachel Bland

    2012-06-01

    Full Text Available The study of uncertainty in decision making is receiving greater attention in the fields of cognitive and computational neuroscience. Several lines of evidence are beginning to elucidate different variants of uncertainty. Particularly, risk, ambiguity and expected and unexpected forms of uncertainty are well articulated in the literature. In this article we review both empirical and theoretical evidence arguing for the potential distinction between three forms of uncertainty; expected uncertainty, unexpected uncertainty and volatility. Particular attention will be devoted to exploring the distinction between unexpected uncertainty and volatility which has been less appreciated in the literature. This includes evidence from computational modelling, neuromodulation, neuroimaging and electrophysiological studies. We further address the possible differentiation of cognitive control mechanisms used to deal with these forms of uncertainty. Particularly we explore a role for conflict monitoring and the temporal integration of information into working memory. Finally, we explore whether the Dual Modes of Control theory provides a theoretical framework for understanding the distinction between unexpected uncertainty and volatility.

  4. Model to estimate radiation dose commitments to the world population from the atmospheric release of radionuclides (LWBR development program)

    International Nuclear Information System (INIS)

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

    1978-02-01

    The equations developed for use in the LWBR environmental statement to estimate the dose commitment over a given time interval to a given organ of the population in the entire region affected by the atmospheric releases of a radionuclide are presented and may be used for any assessment of dose commitments in these regions. These equations define the dose commitments to the world resulting from a released radionuclide and each of its daughters and the sum of these dose commitments provides the total dose commitment accrued from the release of a given radionuclide. If more than one radionuclide is released from a facility, then the sum of the dose commitments from each released nuclide and from each daughter of each released nuclide is the total dose commitment to the world from that facility. Furthermore, if more than one facility is considered as part of an industry, then the sum of the dose commitments from the individual facilities represents the total world dose commitment associated with that industry. The actual solutions to these equations are carried out by the AIRWAY computer program. The writing of this computer program entailed defining in detail the specific representations of the various parameters such as scavenging coefficients, resuspension factors, deposition velocities, dose commitment conversion factors, and food uptake factors, in addition to providing specific numerical values for these types of parameters. The program permits the examination of more than one released nuclide at a time and performs the necessary summing to obtain the total dose commitment to the world accrued from the specified releases

  5. Response of atmospheric CO2 to changes in land use

    International Nuclear Information System (INIS)

    King, A.W.; Emanuel, W.R.; Post, W.M.

    1991-01-01

    This chapter examines how different histories of CO 2 release from past changes in land use influence the simulation of past and future changes in atmospheric CO 2 . The authors first simulate past change in atmospheric CO 2 using reconstructed histories of land-use CO 2 release from a historical-ecological model of land-use change and CO 2 release. They examine the impact of each history on the coincidence between simulated and observed atmospheric CO 2 . They then compare these CO 2 release histories, and their contribution to coincidence or noncoincidence of simulation and observation, with histories reconstructed by deconvolution of the atmospheric CO 2 record. They conclude by exploring the implications of these deconvolved reconstructions for the simulation of future changes in atmospheric CO 2

  6. First estimates of the contribution of CaCO3 precipitation to the release of CO2 to the atmosphere during young sea ice growth

    Science.gov (United States)

    Geilfus, N.-X.; Carnat, G.; Dieckmann, G. S.; Halden, N.; Nehrke, G.; Papakyriakou, T.; Tison, J.-L.; Delille, B.

    2013-01-01

    report measurements of pH, total alkalinity, air-ice CO2 fluxes (chamber method), and CaCO3 content of frost flowers (FF) and thin landfast sea ice. As the temperature decreases, concentration of solutes in the brine skim increases. Along this gradual concentration process, some salts reach their solubility threshold and start precipitating. The precipitation of ikaite (CaCO3.6H2O) was confirmed in the FF and throughout the ice by Raman spectroscopy and X-ray analysis. The amount of ikaite precipitated was estimated to be 25 µmol kg-1 melted FF, in the FF and is shown to decrease from 19 to 15 µmol kg-1 melted ice in the upper part and at the bottom of the ice, respectively. CO2 release due to precipitation of CaCO3 is estimated to be 50 µmol kg-1 melted samples. The dissolved inorganic carbon (DIC) normalized to a salinity of 10 exhibits significant depletion in the upper layer of the ice and in the FF. This DIC loss is estimated to be 2069 µmol kg-1 melted sample and corresponds to a CO2 release from the ice to the atmosphere ranging from 20 to 40 mmol m-2 d-1. This estimate is consistent with flux measurements of air-ice CO2 exchange. Our measurements confirm previous laboratory findings that growing young sea ice acts as a source of CO2 to the atmosphere. CaCO3 precipitation during early ice growth appears to promote the release of CO2 to the atmosphere; however, its contribution to the overall release by newly formed ice is most likely minor.

  7. The role of the LLNL Atmospheric Release Advisory Capability in a FRMAC response to a nuclear power plant incident

    International Nuclear Information System (INIS)

    Baskett, R.L.; Sullivan, T.J.; Ellis, J.S.; Foster, C.S.

    1994-01-01

    The Federal Radiological Emergency Response Plan (FRERP) can provide several emergency response resources in response to a nuclear power plant (NPP) accident if requested by a state or local agency. The primary FRERP technical resources come from the US Department of Energy's (DOE) Federal Radiological Monitoring and Assessment Center (FRMAC). Most of the FRMAC assets are located at the DOE Remote Sensing Laboratory (RSL) at Nellis Air Force Base, Las Vegas, Nevada. In addition, the primary atmospheric dispersion modeling and dose assessment asset, the Atmospheric Release Advisory Capability (ARAC) is located at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. In the early stages of a response, ARAC relies on its automatic worldwide meteorological data acquisition via the Air Force Global Weather Center (AFGWC). The regional airport data are supplemented with data from on-site towers and sodars and the National Oceanographic ampersand Atmospheric Administration's (NOAA) field-deployable real-time rawinsonde system. ARAC is prepared with three-dimensional regional-scale diagnostic dispersion model to simulate the complex mixed fission product release from a reactor accident. The program has been operational for 18 years and is presently developing its third generation system. The current modernization includes faster central computers, a new site workstation system. The current modernization includes faster central computers, a new site workstation system, improvements in its diagnostic dispersion models, addition of a new hybrid-particle source term, and implementation of a mesoscale prognostic model. AS these new capabilities evolve, they will be integrated into the FRMAC's field-deployable assets

  8. A study of the atmospheric dispersion of a high release of krypton-85 above a complex coastal terrain, comparison with the predictions of Gaussian models (Briggs, Doury, ADMS4).

    Science.gov (United States)

    Leroy, C; Maro, D; Hébert, D; Solier, L; Rozet, M; Le Cavelier, S; Connan, O

    2010-11-01

    Atmospheric releases of krypton-85, from the nuclear fuel reprocessing plant at the AREVA NC facility at La Hague (France), were used to test Gaussian models of dispersion. In 2001-2002, the French Institute for Radiological Protection and Nuclear Safety (IRSN) studied the atmospheric dispersion of 15 releases, using krypton-85 as a tracer for plumes emitted from two 100-m-high stacks. Krypton-85 is a chemically inert radionuclide. Krypton-85 air concentration measurements were performed on the ground in the downwind direction, at distances between 0.36 and 3.3 km from the release, by neutral or slightly unstable atmospheric conditions. The standard deviation for the horizontal dispersion of the plume and the Atmospheric Transfer Coefficient (ATC) were determined from these measurements. The experimental results were compared with calculations using first generation (Doury, Briggs) and second generation (ADMS 4.0) Gaussian models. The ADMS 4.0 model was used in two configurations; one takes account of the effect of the built-up area, and the other the effect of the roughness of the surface on the plume dispersion. Only the Briggs model correctly reproduced the measured values for the width of the plume, whereas the ADMS 4.0 model overestimated it and the Doury model underestimated it. The agreement of the models with measured values of the ATC varied according to distance from the release point. For distances less than 2 km from the release point, the ADMS 4.0 model achieved the best agreement between model and measurement; beyond this distance, the best agreement was achieved by the Briggs and Doury models.

  9. Impact of Released Fual Moisture on Atmospheric Dynamics

    Science.gov (United States)

    Brian E. Potter

    2003-01-01

    A common component of fire incident reports and prescribed burn preparations is an estimate of the energy that was or will be released by the fire. Typically, this is based on the energy released by combustion of the fuel load, reduced to account for the energy that is required to evaporate moisture in the fuel materials. (e.g., Byram 1959, Anderson 1968, Simard et al...

  10. Theory of mind for processing unexpected events across contexts.

    Science.gov (United States)

    Dungan, James A; Stepanovic, Michael; Young, Liane

    2016-08-01

    Theory of mind, or mental state reasoning, may be particularly useful for making sense of unexpected events. Here, we investigated unexpected behavior across both social and non-social contexts in order to characterize the precise role of theory of mind in processing unexpected events. We used functional magnetic resonance imaging to examine how people respond to unexpected outcomes when initial expectations were based on (i) an object's prior behavior, (ii) an agent's prior behavior and (iii) an agent's mental states. Consistent with prior work, brain regions for theory of mind were preferentially recruited when people first formed expectations about social agents vs non-social objects. Critically, unexpected vs expected outcomes elicited greater activity in dorsomedial prefrontal cortex, which also discriminated in its spatial pattern of activity between unexpected and expected outcomes for social events. In contrast, social vs non-social events elicited greater activity in precuneus across both expected and unexpected outcomes. Finally, given prior information about an agent's behavior, unexpected vs expected outcomes elicited an especially robust response in right temporoparietal junction, and the magnitude of this difference across participants correlated negatively with autistic-like traits. Together, these findings illuminate the distinct contributions of brain regions for theory of mind for processing unexpected events across contexts. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  11. Atmospheric and surface properties of Mars obtained by infrared spectroscopy on Mariner 9

    Science.gov (United States)

    Conrath, B.; Curran, R.; Hanel, R.; Kunde, V.; Maguire, W.; Pearl, J.; Pirraglia, J.; Welker, J.; Burke, T.

    1973-01-01

    The infrared spectroscopy experiment on Mariner 9 obtained data over much of Mars. Interpretation of the thermal emission of Mars in terms of atmospheric temperatures, wind fields and dynamics, surface temperatures, surface pressure and topography, mineral composition, and minor atmospheric constituents including isotopic ratios, as well as a search for unexpected phenomena are reported.

  12. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of atmospheric dispersion model with improved deposition scheme and oceanic dispersion model

    Science.gov (United States)

    Katata, G.; Chino, M.; Kobayashi, T.; Terada, H.; Ota, M.; Nagai, H.; Kajino, M.; Draxler, R.; Hort, M. C.; Malo, A.; Torii, T.; Sanada, Y.

    2014-06-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Dai-ichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data with atmospheric model simulations from WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information), and simulations from the oceanic dispersion model SEA-GEARN-FDM, both developed by the authors. A sophisticated deposition scheme, which deals with dry and fogwater depositions, cloud condensation nuclei (CCN) activation and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The fallout to the ocean surface calculated by WSPEEDI-II was used as input data for the SEA-GEARN-FDM calculations. Reverse and inverse source-term estimation methods based on coupling the simulations from both models was adopted using air dose rates and concentrations, and sea surface concentrations. The results revealed that the major releases of radionuclides due to FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, the morning of 13 March after the venting event at Unit 3, midnight of 14 March when the SRV (Safely Relief Valve) at Unit 2 was opened three times, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of

  13. An adaptive Bayesian inference algorithm to estimate the parameters of a hazardous atmospheric release

    Science.gov (United States)

    Rajaona, Harizo; Septier, François; Armand, Patrick; Delignon, Yves; Olry, Christophe; Albergel, Armand; Moussafir, Jacques

    2015-12-01

    In the eventuality of an accidental or intentional atmospheric release, the reconstruction of the source term using measurements from a set of sensors is an important and challenging inverse problem. A rapid and accurate estimation of the source allows faster and more efficient action for first-response teams, in addition to providing better damage assessment. This paper presents a Bayesian probabilistic approach to estimate the location and the temporal emission profile of a pointwise source. The release rate is evaluated analytically by using a Gaussian assumption on its prior distribution, and is enhanced with a positivity constraint to improve the estimation. The source location is obtained by the means of an advanced iterative Monte-Carlo technique called Adaptive Multiple Importance Sampling (AMIS), which uses a recycling process at each iteration to accelerate its convergence. The proposed methodology is tested using synthetic and real concentration data in the framework of the Fusion Field Trials 2007 (FFT-07) experiment. The quality of the obtained results is comparable to those coming from the Markov Chain Monte Carlo (MCMC) algorithm, a popular Bayesian method used for source estimation. Moreover, the adaptive processing of the AMIS provides a better sampling efficiency by reusing all the generated samples.

  14. Development, description and validation of a Tritium Environmental Release Model (TERM).

    Science.gov (United States)

    Jeffers, Rebecca S; Parker, Geoffrey T

    2014-01-01

    Tritium is a radioisotope of hydrogen that exists naturally in the environment and may also be released through anthropogenic activities. It bonds readily with hydrogen and oxygen atoms to form tritiated water, which then cycles through the hydrosphere. This paper seeks to model the migration of tritiated species throughout the environment - including atmospheric, river and coastal systems - more comprehensively and more consistently across release scenarios than is currently in the literature. A review of the features and underlying conceptual models of some existing tritium release models was conducted, and an underlying aggregated conceptual process model defined, which is presented. The new model, dubbed 'Tritium Environmental Release Model' (TERM), was then tested against multiple validation sets from literature, including experimental data and reference tests for tritium models. TERM has been shown to be capable of providing reasonable results which are broadly comparable with atmospheric HTO release models from the literature, spanning both continuous and discrete release conditions. TERM also performed well when compared with atmospheric data. TERM is believed to be a useful tool for examining discrete and continuous atmospheric releases or combinations thereof. TERM also includes further capabilities (e.g. river and coastal release scenarios) that may be applicable to certain scenarios that atmospheric models alone may not handle well. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Gastrointestinal causes of sudden unexpected death: A review.

    Science.gov (United States)

    Menezes, Ritesh G; Ahmed, Saba; Pasha, Syed Bilal; Hussain, Syed Ather; Fatima, Huda; Kharoshah, Magdy A; Madadin, Mohammed

    2018-01-01

    Gastrointestinal conditions are a less common cause of sudden unexpected death when compared to other conditions such as cardiovascular conditions, but they are equally important. Various congenital and acquired gastrointestinal conditions that have resulted in sudden unexpected death are discussed. The possible lethal mechanisms behind each condition, along with any associated risk factors or secondary diseases, have been described. Through this article, we aim to highlight the need for physicians to prevent death in such conditions by ensuring that subclinical cases are diagnosed correctly before it is too late and by providing timely and efficacious treatment to the patient concerned. In addition, this review would certainly benefit the forensic pathologist while dealing with cases of sudden unexpected death due to gastrointestinal causes. This article is a review of the major gastrointestinal causes of sudden unexpected death. In addition, related fatal cases encountered occasionally in forensic autopsy practice are also included. There are several unusual and rare causes of life-threatening gastrointestinal bleeding that may lead to sudden unexpected death to cover all the entities in detail. Nevertheless, this article is a general guide to the topic of gastrointestinal causes of sudden unexpected death.

  16. Organically bound tritium (OBT) for various plants in the vicinity of a continuous atmospheric tritium release

    International Nuclear Information System (INIS)

    Vichot, L.; Boyer, C.; Boissieux, T.; Losset, Y.; Pierrat, D.

    2008-01-01

    In order to quantify tritium impact on the environmental, we studied vegetation continuously exposed to a tritiated atmosphere. We chose lichens as bio-indicators, trees for determination of past tritium releases of the Valduc Centre, and lettuce as edible vegetables for dose calculation regarding neighbourhood. The Pasquill and Doury models from the literature were tested to estimate tritium concentration in the air around vegetable for distance from the release point less than 500 m. The results in tree rings show that organically bound tritium (OBT) concentration was strongly correlated with tritium releases. Using the GASCON model, the modelled variation of OBT concentration with distance was correlated with the measurements. Although lichens are recognized as bio-indicators, our experiments show that they were not convenient for environmental surveys because their age is not definitive. Thus, tritium integration time cannot be precisely determined. Furthermore, their biological metabolism is not well known and tritium concentration appears to be largely dependent on species. An average conversion rate of HTO to OBT was determined for lettuce of about 0.20-0.24% h -1 . Nevertheless, even if it is equivalent to values already published in the literature for other vegetation, we have shown that this conversion rate, established by weekly samples, varies by a factor of 10 during the different stages of lettuce development, and that its variation is linked to the biomass derivative

  17. Organically bound tritium (OBT) for various plants in the vicinity of a continuous atmospheric tritium release

    Energy Technology Data Exchange (ETDEWEB)

    Vichot, L. [Commissariat a l' Energie Atomique, CVA/DSTA/SPR/LMSE, 21120 Is-sur-Tille (France)], E-mail: laurent.vichot@cea.fr; Boyer, C.; Boissieux, T.; Losset, Y.; Pierrat, D. [Commissariat a l' Energie Atomique, CVA/DSTA/SPR/LMSE, 21120 Is-sur-Tille (France)

    2008-10-15

    In order to quantify tritium impact on the environmental, we studied vegetation continuously exposed to a tritiated atmosphere. We chose lichens as bio-indicators, trees for determination of past tritium releases of the Valduc Centre, and lettuce as edible vegetables for dose calculation regarding neighbourhood. The Pasquill and Doury models from the literature were tested to estimate tritium concentration in the air around vegetable for distance from the release point less than 500 m. The results in tree rings show that organically bound tritium (OBT) concentration was strongly correlated with tritium releases. Using the GASCON model, the modelled variation of OBT concentration with distance was correlated with the measurements. Although lichens are recognized as bio-indicators, our experiments show that they were not convenient for environmental surveys because their age is not definitive. Thus, tritium integration time cannot be precisely determined. Furthermore, their biological metabolism is not well known and tritium concentration appears to be largely dependent on species. An average conversion rate of HTO to OBT was determined for lettuce of about 0.20-0.24% h{sup -1}. Nevertheless, even if it is equivalent to values already published in the literature for other vegetation, we have shown that this conversion rate, established by weekly samples, varies by a factor of 10 during the different stages of lettuce development, and that its variation is linked to the biomass derivative.

  18. Organically bound tritium (OBT) for various plants in the vicinity of a continuous atmospheric tritium release.

    Science.gov (United States)

    Vichot, L; Boyer, C; Boissieux, T; Losset, Y; Pierrat, D

    2008-10-01

    In order to quantify tritium impact on the environmental, we studied vegetation continuously exposed to a tritiated atmosphere. We chose lichens as bio-indicators, trees for determination of past tritium releases of the Valduc Centre, and lettuce as edible vegetables for dose calculation regarding neighbourhood. The Pasquill and Doury models from the literature were tested to estimate tritium concentration in the air around vegetable for distance from the release point less than 500 m. The results in tree rings show that organically bound tritium (OBT) concentration was strongly correlated with tritium releases. Using the GASCON model, the modelled variation of OBT concentration with distance was correlated with the measurements. Although lichens are recognized as bio-indicators, our experiments show that they were not convenient for environmental surveys because their age is not definitive. Thus, tritium integration time cannot be precisely determined. Furthermore, their biological metabolism is not well known and tritium concentration appears to be largely dependent on species. An average conversion rate of HTO to OBT was determined for lettuce of about 0.20-0.24% h(-1). Nevertheless, even if it is equivalent to values already published in the literature for other vegetation, we have shown that this conversion rate, established by weekly samples, varies by a factor of 10 during the different stages of lettuce development, and that its variation is linked to the biomass derivative.

  19. Deuterium release from Li-D films exposed to atmospheric gases

    Energy Technology Data Exchange (ETDEWEB)

    Gasparyan, Yu. M., E-mail: YMGasparyan@mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); Popkov, A.S.; Krat, S.A.; Pisarev, A.A.; Vasina, Ya. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); Lyublinski, I.E. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); JSC “Red Star”, Electrolitniy proezd 1a, Moscow (Russian Federation); Vertkov, A.V. [JSC “Red Star”, Electrolitniy proezd 1a, Moscow (Russian Federation)

    2017-04-15

    Highlights: • The major part of deuterium desorbs from Li-D films in a very sharp peak at 670–710 K. • Exposure on air leads to intensive deuterium release from the Li-D film at room temperature. • Interaction with water vapor plays a major role in deuterium release from lithium films in the air. - Abstract: Deuterium release from Li-D films co-deposited on a Mo substrate at room temperature in magnetron discharge was investigated by means of thermal desorption spectroscopy. The deuterium concentration in the films was estimated to be D/Li = (14 ± 4)%. TDS from Li-D films just after co-deposition had a sharp peak at 670–710 K. Exposure of deposited Li-D films in the air at room temperature led to deuterium release. Comparison of release in air, water vapor, nitrogen, and oxygen demonstrated that water plays a major role in deuterium release in the air at low temperatures.

  20. Aerosol release from a hot sodium pool and behaviour in inert gas atmosphere

    International Nuclear Information System (INIS)

    Sauter, H.; Schuetz, W.

    1986-01-01

    In the KfK-NALA program, experiments were carried out on the subject of aerosol release from a contaminated sodium pool into inert gas atmosphere under various conditions. Besides the determination of retention factors for fuel and fission products, the sodium aerosol system was investigated and characterized, concerning aerosol generation (evaporation rate), particle size, mass concentration, and deposition behaviour. Pool temperatures were varied between 700 and 1000 K at different geometrical and convective conditions. Technical scale experiments with a 531-cm 2 pool surface area were performed at natural convection in a 2.2-m 3 heated vessel, as well as additional small scale experiments at forced convection and 38.5-cm 2 pool surface area. A best-fit formula is given for the specific evaporation rate into a 400 K argon atmosphere. Approximately, the very convenient relation (dm/dt) (kg/m 2 /h) = 0.1 p (mm Hg) was found. The sodium aerosol diameter lay between 0.6 μm, less than 1 sec after production, and 2.5 μm at maximum concentration. The deposition behaviour was characterized by very small quantities ( 80%) on the bottom cover of the vessel. In the model theoretic studies with the PARDISEKO code, calculations were performed of the mass concentration, particle diameter and deposition behaviour. Agreement with the experimental values could not be achieved until a modulus was introduced to allow for turbulent deposition. (author)

  1. Mammalian play: training for the unexpected.

    Science.gov (United States)

    Spinka, M; Newberry, R C; Bekoff, M

    2001-06-01

    In this review, we present a new conceptual framework for the study of play behavior, a hitherto puzzling array of seemingly purposeless and unrelated behavioral elements that are recognizable as play throughout the mammalian lineage. Our major new functional hypothesis is that play enables animals to develop flexible kinematic and emotional responses to unexpected events in which they experience a sudden loss of control. Specifically, we propose that play functions to increase the versatility of movements used to recover from sudden shocks such as loss of balance and falling over, and to enhance the ability of animals to cope emotionally with unexpected stressful situations. To obtain this "training for the unexpected," we suggest that animals actively seek and create unexpected situations in play through self-handicapping; that is, deliberately relaxing control over their movements or actively putting themselves into disadvantageous positions and situations. Thus, play is comprised of sequences in which the players switch rapidly between well-controlled movements similar to those used in "serious" behavior and self-handicapping movements that result in temporary loss of control. We propose that this playful switching between in-control and out-of-control elements is cognitively demanding, setting phylogenetic and ontogenetic constraints on play, and is underlain by neuroendocrinological responses that produce a complex emotional state known as "having fun." Furthermore, we propose that play is often prompted by relatively novel or unpredictable stimuli, and is thus related to, although distinct from, exploration. We present 24 predictions that arise from our new theoretical framework, examining the extent to which they are supported by the existing empirical evidence and contrasting them with the predictions of four major alternative hypotheses about play. We argue that our "training for the unexpected" hypothesis can account for some previously puzzling

  2. The influence of season of the year on the predicted agricultural consequences of accidental releases of radionuclides to atmosphere

    International Nuclear Information System (INIS)

    Simmonds, J.R.

    1985-02-01

    In Europe, because of the seasonal nature of agricultural practices, the consequences for agriculture of an accidental release of radioactive materials to atmosphere are likely to vary depending upon the time of year when the release occurs. The quantification of this variation is complicated by the need to take into account the introduction of countermeasures to restrict the radiation exposure from ingestion of contaminated foods, and by the presence in accidental releases of radionuclides which persist over several seasons. In this study, the effect on agricultural consequences of accidental releases occurring at different times of the year is examined. The consequences are expressed in terms of the amount of produce affected by restrictions on food supplies and the collective radiation dose from ingestion of food. The investigation has been carried out for three hypothetical releases representing a range of releases postulated for pressurised water reactors (PWRs). The effect of season of the year was determined for accidental releases occurring both in a single, defined set of meteorological conditions and for a range of possible meteorological conditions. For the main part of the study, consideration was limited to agricultural production in the UK only, but the effect of extending the analysis beyond the UK boundary was also considered. The results of the study show that considerable variation can occur in agricultural consequences following an accidental release at different times of the year. For the larger releases considered, this variation is reduced due to the effect of the introduction of countermeasures, particularly when consideration is limited to the UK only. Seasonal variation tends to be greater for the results of a deterministic analysis, which uses a single set of constant meteorological conditions, than for the results of a full probabilistic assessment. From the results presented here it is also seen that for many applications of

  3. The unexpected stability of multiwall nanotubes under high pressure and shear deformation

    International Nuclear Information System (INIS)

    Pashkin, E. Y.; Pankov, A. M.; Kulnitskiy, B. A.; Mordkovich, V. Z.; Perezhogin, I. A.; Karaeva, A. R.; Popov, M. Y.; Sorokin, P. B.; Blank, V. D.

    2016-01-01

    The behavior of multiwall carbon nanotubes under a high pressure (up to 55 GPa) combined with shear deformation was studied by experimental and theoretical methods. The unexpectedly high stability of the nanotubes' structure under high stresses was observed. After the pressure was released, we observed that the nanotubes had restored their shapes. Atomistic simulations show that the hydrostatic and shear stresses affect the nanotubes' structure in a different way. It was found that the shear stress load in the multiwall nanotubes' outer walls can induce their connection and formation of an amorphized sp"3-hybridized region but internal core keeps the tubular structure.

  4. The unexpected stability of multiwall nanotubes under high pressure and shear deformation

    Energy Technology Data Exchange (ETDEWEB)

    Pashkin, E. Y.; Pankov, A. M.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); Perezhogin, I. A. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Lomonosov Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Karaeva, A. R. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Popov, M. Y.; Sorokin, P. B.; Blank, V. D. [Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190 (Russian Federation); Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700 (Russian Federation); National University of Science and Technology MISiS, 4 Leninskiy Prospekt, Moscow 119049 (Russian Federation)

    2016-08-22

    The behavior of multiwall carbon nanotubes under a high pressure (up to 55 GPa) combined with shear deformation was studied by experimental and theoretical methods. The unexpectedly high stability of the nanotubes' structure under high stresses was observed. After the pressure was released, we observed that the nanotubes had restored their shapes. Atomistic simulations show that the hydrostatic and shear stresses affect the nanotubes' structure in a different way. It was found that the shear stress load in the multiwall nanotubes' outer walls can induce their connection and formation of an amorphized sp{sup 3}-hybridized region but internal core keeps the tubular structure.

  5. Iodine release from sodium pool combustion

    International Nuclear Information System (INIS)

    Sagawa, N.; Fukushima, Y.; Yokota, N.; Akagane, K.; Mochizuki, K.

    1979-01-01

    Iodine release associated with sodium pool combustion was determined by heating 20 gr sodium containing sodium iodide, which was labelled with 131 I and dissolved in the sodium in concentration of 1∼1,000 ppm, to burn on a nickel crucible in conditioned atmosphere in a closed vessel of 0.4 m 3 . Oxygen concentration was changed in 5∼21% and humidity in 0∼89% by mixing nitrogen gas and air. Combustion products were trapped by a Maypack filter composed of particle filters, copper screens and activated charcoal beds and by a glass beads pack cooled by liquid argon. Iodine collected on these filter elements was determined by radio-gas chromatography. When the sodium sample burned in the atmosphere of air at room temperature, the release fractions observed were 6∼33% for sodium and 1∼20% for iodine added in the sodium. The release iodine was present in aerosol at a ratio of 98%, and the remainder in the gas form. The release fraction of iodine trended to decrease as oxygen concentration and humidity in the atmosphere increased. No organic iodide was detected in the combustion products. (author)

  6. Comprehensive default methodology for the analysis of exposures to mixtures of chemicals accidentally released to the atmosphere

    International Nuclear Information System (INIS)

    Craig, D.K.; Baskett, R.L.; Powell, T.J.; Davis, J.S.; Dukes, L.L.; Hansen, D.J.; Petrocchi, A.J.; Sutherland, P.J.

    1997-01-01

    Safety analysis of Department of Energy (DOE) facilities requires consideration of potential exposures to mixtures of chemicals released to the atmosphere. Exposure to chemical mixtures may lead to additive, synergistic, or antagonistic health effects. In the past, the consequences of each chemical have been analyzed separately. This approach may not adequately protect the health of persons exposed to mixtures. However, considerable time would be required to evaluate all possible mixtures. The objective of this paper is to present reasonable default methodology developed by the EFCOG Safety Analysis Working Group Nonradiological Hazardous Material Subgroup (NHMS) for use in safety analysis within the DOE Complex

  7. POPFOOD - a computer code for calculating ingestion collective doses from continuous atmospheric releases

    International Nuclear Information System (INIS)

    Hotson, J.; Stacey, A.; Nair, S.

    1980-07-01

    The basic methodology incorporated in the POPFOOD computer code is described, which may be used to calculate equilibrium collective dose rates associated with continuous atmospheric releases and arising from consumption of a broad range of food products. The standard data libraries associated with the code are also described. These include a data library, based on the 1972 agricultural census, describing the spatial distribution of production, in England, Wales and Scotland, of the following food products: milk; beef and veal; pork bacon and ham; poultrymeat; eggs; mutton and lamb; root vegetables; green vegetables; fruit; cereals. Illustrative collective dose calculations were made for the case of 1 Ci per year emissions of 131 I, tritium and 14 C from a typical rural UK site. The calculations indicate that the ingestion pathway results in a greater collective dose than that via inhalation, with the contributions from consumption of root and green vegetables, and cereals being of comparable significance to that from liquid milk consumption, in all three cases. (author)

  8. Optimal selection of the time of hazardous operations, and prediction of consequences of atmospheric releases of harmful matter: the 'Kursk' submarine study

    International Nuclear Information System (INIS)

    Baklanov, A.; Havskov Sorensen, J.; Mahura, A.

    2003-01-01

    Full text: There are objects and events with higher than normal risks of accidental atmospheric releases (nuclear, chemical, biological, etc.) during certain periods. Such accidents or events may occur due to natural hazards, human errors, terror acts, and may take place during transportation of waste or during various operations at high risk. A methodology for risk assessment is presented including two approaches: 1) probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2) forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach can be applied during the preparation stage, and the second during the operation stage. The methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning) of the 'Kursk' nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137 Cs) show that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allow identifying the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, forecasts of possible consequences during phases of high and medium risks are performed based on a unit hypothetical release, e.g. 1 Bq. The analysis shows possible deposition fractions of 10 -11 Bq/m 2 over the Kola Peninsula, and 10 -12 -10 -13 Bq/m 2 for the remote areas of Scandinavia and Northwest Russia. The methodology may be applied to any potentially dangerous object involving a risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature. In the present paper, the methodology is applied to the handling of the

  9. Release enhancement of tritium from graphite by addition of hydrogen

    International Nuclear Information System (INIS)

    Saeki, Masakatsu; Masaki, N.M.

    1989-01-01

    The release behavior of tritium from graphite was studied in pure He and He + H 2 atmosphere. The release from powdered graphite was significantly enhanced in hydrogen environment. Apparent diffusion coefficients of tritium in graphite also became much higher in an atmosphere containing hydrogen than values obtained in pure helium atmosphere. A careful investigation of the release processes resulted in the conclusion that the most important process of tritium behaviour in graphite was diffusion, but the desorption process of tritium from the surface played a significant role. The enhancement of the desorption process was controlled by atomic hydrogen. (orig.)

  10. A study of wet deposition of atmospheric tritium releases at the Ontario Power Generation, Pickering Nuclear Generating Station

    International Nuclear Information System (INIS)

    Crooks, G.; DeWilde, J.; Yu, L.

    2001-01-01

    The Ontario Power Generation,Pickering Nuclear Generating Station (PNGS) has been investigating deposition of atmospheric releases of tritium on their site. This study has included numerical dispersion modelling studies conducted over the past three years, as well as an ongoing field monitoring study. The following paper will present results of the field monitoring study and make comparisons to the numerical modelling. The results of this study could be of potential use to nuclear stations in quantifying tritium deposition in near field regions where building wake effects dominate pollutant dispersion

  11. AXAIR: A Computer Code for SAR Assessment of Plume-Exposure Doses from Potential Process-Accident Releases to Atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Pillinger, W.L.

    2001-05-17

    This report describes the AXAIR computer code which is available to terminal users for evaluating the doses to man from exposure to the atmospheric plume from postulated stack or building-vent releases at the Savannah River Plant. The emphasis herein is on documentation of the methodology only. The total-body doses evaluated are those that would be exceeded only 0.5 percent of the time based on worst-sector, worst-case meteorological probability analysis. The associated doses to other body organs are given in the dose breakdowns by radionuclide, body organ and pathway.

  12. Development of three-dimensional trajectory model for detecting source region of the radioactive materials released into the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kyung Suk; Park, Ki Hyun; Min, Byung Il; Kim, Sora; Yang, Byung Mo [Nuclear Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-05-15

    It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

  13. ACCI38 XL 2: a useful tool for dose assessment in case of accidental atmospheric releases of radionuclides

    International Nuclear Information System (INIS)

    Thomassin, A.; Merle-Szeremeta, A.

    2002-01-01

    In the scope of its assignments in the field of nuclear risks, the French Institute for Radiation protection and Nuclear Safety (IRSN) develops tools to assess the impact of nuclear facilities on their environment and surrounding populations. The code ACCI38 XL 2 is a tool dedicated to the assessment of integrated concentrations in the environment and of dosimetric consequences on man, in case of accidental atmospheric releases of radionuclides (up to 170 radionuclides). This code is widely used by IRSN for studies on accidents, mainly for the analysis of regulatory documents from nuclear operators. The aim of this communication is to present the main features of the model used in the code ACCI38 XL 2, and to give details about the code. After a general presentation of the model, a detailed description of atmospheric dispersion, transfer in the environment and radiological impact is given. Then, some information on parameters and limitations of the model and the code are presented

  14. A new look at 99Tc releases to the atmosphere

    International Nuclear Information System (INIS)

    Till, J.E.; Hoffman, F.O.; Dunning, D.E. Jr.

    1979-01-01

    Recent experimental data suggest that the uptake of 99 Tc by vegetation from soils may be two to three orders of magnitude higher than the 0.25 value currently being used in radiological assessments. Following a survey of the literature, a concentration factor of 50 was applied to evaluate the dose from a 1.0 Ci/yr-release to the atmosphere by a hypothetical uranium enrichment facility. Doses to the GI tract and thyroid of an adult living 1600 m from the facility were 18 mrem and 80 mrem respectively. These doses are delivered entirely through transport of 99 Tc through food chain pathways. This assessment indicates a potential for 99 Tc exposures to exceed recently proposed standards of the U.S. Environmental Protection Agency in 40 CFR 190. The previously assumed concentration factor of 0.25 would have produced corresponding doses of 0.13 mrem to the GI tract and 0.57 mrem to the thyroid. The results of this analysis demonstrate the need for additional research on the environmental behaviour and dosimetry of 99 Tc. In particular, data are needed to elucidate the retention of 99 Tc in soils and the uptake of 99 Tc by edible vegetation in field studies simulating chronic exposure conditions. Data on the uptake and retention of 99 Tc in humans are also necessary to improve the reliability of dose conversion factors for specific organs and various age groups. (author)

  15. Evaluation of food contamination and health risks caused by radioactive fallout released from atmospheric nuclear detonation tests

    International Nuclear Information System (INIS)

    Shimada, Yoko; Ito, Yoshihiko; Yoneda, Minoru; Morisawa, Shinsuke

    2011-01-01

    Before Fukushima Daiichi nuclear disaster, radionuclide like 137 Cs released from atmospheric nuclear detonation tests and Chernobyl disaster has been transported worldwide in the environment and finally taken up by humans through various pathways. In this research, dietary intake of 137 Cs and the related health risks to Japanese caused by chronic global radioactive food contamination from 1945 to 2010 were evaluated by using the mathematical model for the evaluation of global distribution of 137 Cs with food ingestion and domestic and international food supply model. The results of this evaluation can show a background situation before Fukushima disaster and give important information for the risk assessment of this disaster. (author)

  16. System to forecast health effects in order to determine necessary counter-measures in case an accidental atmospheric release

    International Nuclear Information System (INIS)

    Merchant, T.E.; Parmentier, N.

    1985-01-01

    In most accident situations involving radioactivity, the required data are the quantitative evaluation of the relevant constituents of the release and the dose factors applicable for these constituents. In the problem of an atmospheric release of radioactivity a third group of data also comes into play, the meteorological conditions at the site and time of the accident. The solution to this problem is the construction of a computer code which, by employing acquired compositions of the release as well as physical accident conditions (at the time of the incident), can be effectively run to calculate and present useful dosimetric data. To meet this need, an interactive computer program has been constructed by the Institut de Protection et de Surete Nucleaire of the Commissariat a l'Energie Atomique which calculates the gamut of dosimetric and statistical information for a region of accidental radiological concern. Application of the program is such that it outputs dosimetric information and other important data in a form independent of the site under consideration, allowing, at the same time, the computation of the same information for areas where demographics show them to be of the highest radiological concern. All this is done after requiring minimal user input

  17. Unexpected allergic reactions to food, a prospective study

    NARCIS (Netherlands)

    Michelsen-Huisman, A.D.; Os-Medendorp, H. van; Versluis, A.; Kruizinga, A.G.; Castenmiller, J.J.M.; Noteborn, H.P.J.M.; Houben, G.F.; Knulst, A.C.

    2013-01-01

    Unexpected reactions occur in patients with food allergy, but frequency data are scare. This prospective study investigates the frequency, severity and causes of unexpected allergic reactions to food in adults with a doctor's diagnosed food allergy. Participants complete an online questionnaire

  18. A guide to the use of TIRION. A computer programme for the calculation of the consequences of releasing radioactive material to the atmosphere

    International Nuclear Information System (INIS)

    Kaiser, G.D.

    1976-11-01

    A brief description is given of the contents of TIRION, which is a computer program that has been written for use in calculations of the consequences of releasing radioactive material to the atmosphere. This is followed by a section devoted to an account of the control and data cards that make up the input to TIRION. (author)

  19. Operational control of material release and discharges from nuclear power plant

    International Nuclear Information System (INIS)

    Szabo, I. C.; Ranga, T.; Daroczi, L.; Deme, S.; Kerekes, A.

    2003-01-01

    The operational control of radioactive materials during atmospheric release and aquatic discharge from nuclear power plant is a licensing criterion for NPPs. Originally at the Paks NPP the release control was based on activity limits for four groups of elements. These groups were noble gases, long living radio-aerosols, radioiodine and radiostrontium for atmospheric release and specified activity limit for beta emitters, strontium and tritium for aquatic discharge into Danube. These groups were controlled with proper sampling and/or measuring instrumentation. The limit for atmospheric release was given as a 30-day moving average, for liquid discharges the annual limit was stipulated. The new release and discharge limitation system is based on the environmental dose limitation. The dose constraint for Paks NPP is 90 Sv/year of the critical group for all release pathways and the investigation dose limit is equal to 27 Sv/year. The regulation did not subdivide the dose limit for atmospheric and liquid components but for operational control subdivision of dose limits for atmospheric release and aquatic discharge and shorter time period (one day-one month) seems to be useful. The subdivision can be based on past release data and/or previous activity limits. To satisfy dose below the investigation dose limit there should be a proper operation control level for each separately measured component and pathway belonging to reasonable time interval significantly shorter than one year. The main task of the NPP staff is elaboration of reasonable control levels and reference time intervals for different radionuclide and element groups to be used in operational control. Operational control levels are based on measured daily or monthly release rates. In case of noble gases, aerosols and iodine the daily release rates have several sharp peaks per year. Operational control levels give opportunity to detect these peaks for internal investigation purposes. Investigation release limits

  20. Radiocarbon of Respired CO2 Following Fire in Alaskan Boreal Forest: Can Disturbance Release Old Soil Carbon to the Atmosphere?

    Science.gov (United States)

    Schuur, E. A.; Randerson, J. A.; Fessenden, J.; Trumbore, S. E.

    2002-12-01

    Fire in the boreal forest releases carbon stored in vegetation and soil to the atmosphere. Following fire, microbial decomposition is stimulated by inputs of plant detritus and changes in soil microclimate, which can result in large losses of carbon. Furthermore, warmer summer soil temperatures and deeper thaw depths in burned ecosystems may make carbon that was previously climatically protected by low soil temperatures susceptible to decomposition. We used radiocarbon measurements to estimate the age of carbon released by soil respiration following fire in two black spruce (Picea mariana) forests in interior Alaska that burned during the summer of 1999. To isolate soil respiration, we established manipulated plots where vegetation was prevented from recolonizing, and paired control plots in nearby unburned forest. Soil respiration radiocarbon signatures in the burned manipulation ranged from +112\\permil to +192\\permil and differed significantly from the unburned controls that ranged from +100\\permil to +130\\permil. Burned plots appear to respire older carbon than unburned forest, which could either be due to the stimulation of decomposition of intermediate age soil organic matter pools, to the lack of plant respiration that reflects the atmospheric radiocarbon signature of +92\\permil, or both. At least during the initial phase following fire, these data suggest that carbon fluxes from soil are dominated by soil organic matter pools with decadal scale turnover times.

  1. Diffusion-type model of the global carbon cycle for the estimation of dose to the world population from releases of carbon-14 to the atmosphere

    International Nuclear Information System (INIS)

    Killough, G.G.

    1977-05-01

    A nonlinear dynamic model of the exchange of carbon among the atmosphere, terrestrial biosphere, and ocean is described and applied to estimating the radiation dose to the world's population from the release of 14 C to the atmosphere from the nuclear power industry. A computer implementation of the model, written in the IBM Continuous System Modeling Program III (CSMP III) simulation language, is presented. The model treats the ocean as a diffusive medium with respect to vertical transport of carbon, and the nonlinear variation of CO 2 partial pressure with the total inorganic carbon concentration in surface waters is taken into account in calculating the transfer rate from ocean to atmosphere. Transfers between the atmosphere and terrestrial biosphere are represented by nonlinear equations which consider CO 2 fertilization and impose a constraint on the ultimate total carbon mass in the biosphere

  2. Impact of rainstorm and runoff modeling on predicted consequences of atmospheric releases from nuclear reactor accidents

    International Nuclear Information System (INIS)

    Ritchie, L.T.; Brown, W.D.; Wayland, J.R.

    1980-05-01

    A general temperate latitude cyclonic rainstorm model is presented which describes the effects of washout and runoff on consequences of atmospheric releases of radioactive material from potential nuclear reactor accidents. The model treats the temporal and spatial variability of precipitation processes. Predicted air and ground concentrations of radioactive material and resultant health consequences for the new model are compared to those of the original WASH-1400 model under invariant meteorological conditions and for realistic weather events using observed meteorological sequences. For a specific accident under a particular set of meteorological conditions, the new model can give significantly different results from those predicted by the WASH-1400 model, but the aggregate consequences produced for a large number of meteorological conditions are similar

  3. The release of fission products from uranium metal: a review

    International Nuclear Information System (INIS)

    Minshall, P.C.

    1989-03-01

    The literature on the release of fission products as gaseous species from irradiated uranium metal in oxidising atmospheres has been reviewed. Release of actinides and of fission products as spalled particulate were not considered. Data is given on the release in air, carbon dioxide, steam and mixtures of steam and air. The majority of data discussed lie between 800 and 1200 0 C though some results for xenon, krypton and iodine releases below 800 0 C are given. Two measures of fission product release are discussed: the release fraction, F(tot), which is the ratio of the total release to the initial inventory, and the fractional release, F(ox), which is the fraction released from the oxidised metal. The effect of burn-up, atmosphere and temperature on F(tot) and F(ox) is examined and the conditions under which the release fraction, F(tot) is proportional to the extent of oxidation discussed. (author)

  4. An unexpected pulmonary bystander

    NARCIS (Netherlands)

    Wouthuyzen-Bakker, M.; Vorm, van der P. A.; Koning, K. J.; van der Werf, T. S.

    A 30-year-old man from Eritrea was admitted with a pulmonary bacterial abscess. Unexpectedly, histopathology of the resected lobe also revealed an infection with Schistosoma mansoni with surrounding granulomatous tissue and fibrosis. Patients from endemic areas are often asymptomatic with blood

  5. Maxdose-SR and popdose-SR routine release atmospheric dose models used at SRS

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, G. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Trimor, P. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-28

    MAXDOSE-SR and POPDOSE-SR are used to calculate dose to the offsite Reference Person and to the surrounding Savannah River Site (SRS) population respectively following routine releases of atmospheric radioactivity. These models are currently accessed through the Dose Model Version 2014 graphical user interface (GUI). MAXDOSE-SR and POPDOSE-SR are personal computer (PC) versions of MAXIGASP and POPGASP, which both resided on the SRS IBM Mainframe. These two codes follow U.S. Nuclear Regulatory Commission (USNRC) Regulatory Guides 1.109 and 1.111 (1977a, 1977b). The basis for MAXDOSE-SR and POPDOSE-SR are USNRC developed codes XOQDOQ (Sagendorf et. al 1982) and GASPAR (Eckerman et. al 1980). Both of these codes have previously been verified for use at SRS (Simpkins 1999 and 2000). The revisions incorporated into MAXDOSE-SR and POPDOSE-SR Version 2014 (hereafter referred to as MAXDOSE-SR and POPDOSE-SR unless otherwise noted) were made per Computer Program Modification Tracker (CPMT) number Q-CMT-A-00016 (Appendix D). Version 2014 was verified for use at SRS in Dixon (2014).

  6. Generation and release of radioactive gases in LLW disposal facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S. [Harvard School Public Health, Boston, MA (United States); Simonson, S.A. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-02-01

    The atmospheric release of radioactive gases from a generic engineered LLW disposal facility and its radiological impacts were examined. To quantify the generation of radioactive gases, detailed characterization of source inventory for carbon-14, tritium, iodine-129, krypton-85, and radon-222, was performed in terms of their activity concentrations; their distribution within different waste classes, waste forms and containers; and their subsequent availability for release in volatile or gaseous form. The generation of gases was investigated for the processes of microbial activity, radiolysis, and corrosion of waste containers and metallic components in wastes. The release of radionuclides within these gases to the atmosphere was analyzed under the influence of atmospheric pressure changes.

  7. Final safety analysis report for the atmospheric protection system

    International Nuclear Information System (INIS)

    1976-06-01

    An Atmospheric Protection System (APS) has been constructed at the Idaho Chemical Processing Plant to minimize the release of radioactive particulate material to the atmosphere from nonroutine occurrences. Existing off-gas cleanup systems remove radioactive particulates to well below allowable limits for controlled areas before release to the plant stack. Previously all ventilation air from process cells was discharged to the stack without treatment. The APS provides continuous filtration of all ventilation air from process cells and backup filtration of all process off gases before they are released to the atmosphere. A safety analysis of the potential hazards associated with the APS has been completed. The review indicates that the system is capable of withstanding design basis natural phenomena including a flood, tornado, and earthquake without releasing unacceptable amounts of radioactive particulate from the filters to the environment. An in-cell explosion, fire, mechanical damage, and other postulated accident situations were investigated. From these, the design basis accident postulated for the facility is complete release of the maximum amount of radioactive particulate collected on the 104 ventilation air HEPA filters to the atmosphere via the 250-foot high stack. Even though the release of all the radioactive particulate contained on the filters is hardly credible, it would not present an unacceptable hazard to personnel on or offsite

  8. Unexpected pathological findings after laparoscopic cholecystectomy - analysis of 1131 cases.

    Science.gov (United States)

    Bartosiak, Katarzyna; Liszka, Maciej; Drazba, Tomasz; Paśnik, Krzysztof; Janik, Michal R

    2018-03-01

    Gallbladder specimens are routinely sent for histopathological examination after cholecystectomy in order to rule out the presence of unexpected pathological findings. To establish the overall incidence of unexpected pathological findings in patients who underwent laparoscopic cholecystectomy for symptomatic gallbladder disease and determine whether the macroscopic appearance of the gallbladder in ultrasound examination could be a valid method for identifying patients with gallbladder malignancy. A retrospective study was conducted between 2013 and 2015. All histological reports (n = 1131) after cholecystectomy were searched for unexpected pathological findings. In cases where unexpected pathological findings were identified the additional analysis of preoperative abdominal ultrasound examination (USG) was done to determine the usefulness of USG in diagnosis of gallbladder malignancy. Of the 1131 patients included in the study, 356 (31.47%) were male and 774 (68.43%) were female. Unexpected pathological findings were present in 21 cases. The overall incidence of unexpected pathological findings was 1.86%. Only in 5 patients were suspicious appearances of gallbladder observed in preoperative ultrasound examination. In 16 patients there was no suspicion of malignancy. The positive predictive value of USG was 0.238. The incidence of unexpected pathological findings after laparoscopic cholecystectomy was 1.86%. Ultrasonography has low positive predictive value for identifying patients with malignant findings in a gallbladder specimen.

  9. Estimation of radionuclide releases in atmosphere from Cernavoda NPP based on continuous gaseous effluent monitoring

    International Nuclear Information System (INIS)

    Bobric, E.; Murgoci, S.; Popescu, I.; Ibadula, R.

    2001-01-01

    Monitoring of gaseous effluents from Cernavoda NPP is performed to assess the environmental impact of the plant operation. The results of the monitoring program are used to evaluate the population doses in order to ensure that the emissions of radionuclides in air are below regulatory limits and radiation doses are maintained ALARA. It complements, but is independent from the Operational Environmental Monitoring Program for Cernavoda NPP. Gaseous effluent monitors provide continuous indication of the radioactivity content in atmospheric emissions. Except for noble gases, these monitors also collect samples for later detailed analysis in the station Health Physics Laboratory. This paper presents the main equipment and the results of the gaseous effluents monitoring program in order to assess the impact of Cernavoda NPP operation and to predict the future releases as function of radionuclides concentrations in CANDU systems, based on the identified trends.(author)

  10. Readily releasable pool of synaptic vesicles measured at single synaptic contacts.

    Science.gov (United States)

    Trigo, Federico F; Sakaba, Takeshi; Ogden, David; Marty, Alain

    2012-10-30

    To distinguish between different models of vesicular release in brain synapses, it is necessary to know the number of vesicles of transmitter that can be released immediately at individual synapses by a high-calcium stimulus, the readily releasable pool (RRP). We used direct stimulation by calcium uncaging at identified, single-site inhibitory synapses to investigate the statistics of vesicular release and the size of the RRP. Vesicular release, detected as quantal responses in the postsynaptic neuron, showed an unexpected stochastic variation in the number of quanta from stimulus to stimulus at high intracellular calcium, with a mean of 1.9 per stimulus and a maximum of three or four. The results provide direct measurement of the RRP at single synaptic sites. They are consistent with models in which release proceeds from a small number of vesicle docking sites with an average occupancy around 0.7.

  11. 42 CFR 493.861 - Standard; Unexpected antibody detection.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; Unexpected antibody detection. 493.861 Section 493.861 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN..., Or Any Combination of These Tests § 493.861 Standard; Unexpected antibody detection. (a) Failure to...

  12. Diffusion rates for elevated releases

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1983-11-01

    A search of the literature related to diffusion from elevated sources has determined that an adequate data base exists for use in developing parameterizations for estimating diffusion rates for material released from free standing stacks at nuclear power plants. A review of published data analyses indicates that a new parameterization of horizontal diffusion rates specifically for elevated releases is not likely to significantly change the magnitudes of horizontal diffusion coefficients on the average. However, the uncertainties associated with horizontal diffusion coefficient estimates under any given set of atmospheric conditions could be reduced by a new parameterization. Similarly, a new parameterization of vertical diffusion rates would be unlikely to significantly alter the magnitudes of diffusion coefficients for unstable atmospheric conditons. However, for neutral and stable atmospheric conditions, a new parameterization of vertical diffusion rates might increase vertical diffusion coefficients significantly. The increase would move ground-level time-integrated concentration maxima closer to the plant and would increase the maxima. 55 references, 2 figures, 4 tables

  13. A review of ''The potential effects of release of krypton-85''

    International Nuclear Information System (INIS)

    Saunders, C.P.R.

    1993-06-01

    A Report into the potential effects of the release of Krypton-85 from the Thermal Oxide Reprocessing Plant (THORP) at Sellafield, was commissioned by British Nuclear Fuels Ltd. The report dealt with the atmospheric impact of the release of Krypton-85 and considered specifically the areas of atmospheric electricity, ionisation, aerosols and conductivity, in terms of the releases of Krypton-85 from THORP. This present review has three objectives: to consider the atmospheric effects of the proposed discharges from THORP, to comment upon the magnitude of the postulated effects from Krypton-85 discharges compared with those from other sources of radioactivity in the atmosphere, and, to comment on the conclusions drawn by the authors of the report. This review was conducted under the aegis of the United Kingdom Inspectorate of Pollution. (author)

  14. Deposition of radionuclides and their subsequent relocation in the environment following an accidental release to the atmosphere

    International Nuclear Information System (INIS)

    Underwood, B.Y.; Roed, J.; Paretzke, H.G.

    1993-01-01

    The objective of the project is to improve, as necessary, the models and parameterizations used in estimating the intensity and spatial distribution of deposited activity, and the total health/economic impact of such deposits in assessments of the consequences of accidental releases of radioactivity. The study comprises the influence of various weather conditions on deposition; the resuspension of deposited 137 Cs activity; the weathering of deposits in urban and rural environments; the ultimate fate and dosimetric impact of radionuclides carried by urban run-off water; the impact of the atmosphere's dispersion capabilities. Objectives and results of the four contributions to the project for the reporting period are presented. (R.P.) 5 refs., 4 figs., 1 tab

  15. Calculations of individual doses for Techa River Cohort members exposed to atmospheric radioiodine from Mayak releases

    Energy Technology Data Exchange (ETDEWEB)

    Napier, Bruce A.; Eslinger, Paul W.; Tolstykh, Evgenia I.; Vorobiova, Marina I.; Tokareva, Elena E.; Akhramenko, Boris N.; Krivoschapov, Victor A.; Degteva, Marina O.

    2017-11-01

    Time-dependent thyroid doses were reconstructed for Techa River Cohort members living near the Mayak production facilities from 131I released to the atmosphere for all relevant exposure pathways. The calculational approach uses four general steps: 1) construct estimates of releases of 131I to the air from production facilities; 2) model the transport of 131I in the air and subsequent deposition on the ground and vegetation; 3) model the accumulation of 131I in soil, water, and food products (environmental media); and 4) calculate individual doses by matching appropriate lifestyle and consumption data for the individual to concentrations of 131I in environmental media. The dose calculations are implemented in a Monte Carlo framework that produces best estimates and confidence intervals of dose time-histories. The 131I contribution was 75-99% of the thyroid dose. The mean total thyroid dose for cohort members was 193 mGy and the median was 53 mGy. Thyroid doses for about 3% of cohort members were larger than 1 Gy. About 7% of children born in 1940-1950 had doses larger than 1 Gy. The uncertainty in the 131I dose estimates is low enough for this approach to be used in regional epidemiological studies.

  16. Stability of vertical posture explored with unexpected mechanical perturbations: synergy indices and motor equivalence.

    Science.gov (United States)

    Yamagata, Momoko; Falaki, Ali; Latash, Mark L

    2018-03-21

    We explored the relations between indices of mechanical stability of vertical posture and synergy indices under unexpected perturbations. The main hypotheses predicted higher posture-stabilizing synergy indices and higher mechanical indices of center of pressure stability during perturbations perceived by subjects as less challenging. Healthy subjects stood on a force platform and held in fully extended arms a bar attached to two loads acting downward and upward. One of the loads was unexpectedly released by the experimenter causing a postural perturbations. In different series, subjects either knew or did not know which of the two loads would be released. Forward perturbations were perceived as more challenging and accompanied by co-activation patterns among the main agonist-antagonist pairs. Backward perturbation led to reciprocal muscle activation patterns and was accompanied by indices of mechanical stability and of posture-stabilizing synergy which indicated higher stability. Changes in synergy indices were observed as early as 50-100 ms following the perturbation reflecting involuntary mechanisms. In contrast, predictability of perturbation direction had weak or no effect on mechanical and synergy indices of stability. These observations are interpreted within a hierarchical scheme of synergic control of motor tasks and a hypothesis on the control of movements with shifts of referent coordinates. The findings show direct correspondence between stability indices based on mechanics and on the analysis of multi-muscle synergies. They suggest that involuntary posture-stabilizing mechanisms show synergic organization. They also show that predictability of perturbation direction has strong effects on anticipatory postural adjustment but not corrective adjustments. We offer an interpretation of co-activation patterns that questions their contribution to postural stability.

  17. Training to handle unexpected events

    International Nuclear Information System (INIS)

    Hamlin, K.W.

    1987-01-01

    The importance of conducting hands-on training to deal with complex situations is well recognized. Since most utilities now own or have ordered their own control room simulators, access to simulator training facilities has improved greatly. Most utilities now have a control room shift rotation that includes a dedicated training shift. The opportunities for practicing operational control over unexpected and off-normal events are just beginning to be recognized. Areas that are being enhanced include teamwork training, diagnostics training, expanded simulator training programs, improvements in simulator instructor training, emergency procedures training, and training on the use of probabilistic risk assessment studies. All these efforts are aimed at the goal of improving the plant staff's ability to cope with unexpected and off-normal events

  18. Pressure-sensitive release mechanism for radiosonde applications

    International Nuclear Information System (INIS)

    Kulhanek, F.C.

    1975-01-01

    As part of the 1975 planetary boundary layer field experimental program, miniature radiosondes attached to pilot balloons were released into the atmosphere for routine sampling of the vertical temperature distribution. A new releasing mechanism used to continue sampling during descent by parachute is described

  19. Intermediate range atmospheric transport and technology assessments: nuclear pollutants

    International Nuclear Information System (INIS)

    Rohwer, P.S.; Hoffman, F.O.; Miller, C.W.

    1981-01-01

    Mathematical models have been used to assess potential impacts of radioactivity releases during all phases of our country's development of nuclear power. Experience to date has shown that in terms of potential dose to man, the most significant releases of radioactivity from nuclear fuel cycle facilities are those to the atmosphere. Our ability to predict atmospheric dispersion will, therefore, ultimately affect our capability to understand and assess the significance of both routine and accidental discharges of radionuclides. Assessment of potential radiological exposures from postulated routine and accidental releases of radionuclides from the fast-breeder reactor will require the use of atmospheric dispersion models, and the design, siting, and licensing of breeder reactor fuel cycle facilities will be influenced by the predictions made by these models

  20. Postulated weather modification effects of large energy releases

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

    1977-02-01

    Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific.

  1. Postulated weather modification effects of large energy releases

    International Nuclear Information System (INIS)

    Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

    1977-02-01

    Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific

  2. Forecasting the consequences of accidental releases of radionuclides in the atmosphere from ensemble dispersion modelling

    International Nuclear Information System (INIS)

    Galmarini, S.; Bianconi, R.; Bellasio, R.; Graziani, G.

    2001-01-01

    The RTMOD system is presented as a tool for the intercomparison of long-range dispersion models as well as a system for support of decision making. RTMOD is an internet-based procedure that collects the results of more than 20 models used around the world to predict the transport and deposition of radioactive releases in the atmosphere. It allows the real-time acquisition of model results and their intercomparison. Taking advantage of the availability of several model results, the system can also be used as a tool to support decision making in case of emergency. The new concept of ensemble dispersion modelling is introduced which is the basis for the decision-making application of RTMOD. New statistical parameters are presented that allow gathering the results of several models to produce a single dispersion forecast. The devised parameters are presented and tested on the results of RTMOD exercises

  3. Atmospheric dispersion of radioactive releases: Computer code DIASPORA

    International Nuclear Information System (INIS)

    Synodinou, B.M.; Bartzis, J.M.

    1982-05-01

    The computer code DIASPORA is presented. Air and ground concentrations of an airborne radioactive material released from an elevated continuous point source are calculated using Gaussian plume models. Dry and wet deposition as well as plume rise effects are taken into consideration. (author)

  4. Exponential growth and atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Laurmann, J.A.; Rotty, R.M.

    1983-01-01

    The adequacy of assumptions required to project atmospheric CO 2 concentrations in time frames of practical importance is reviewed. Relevant issues concern the form assumed for future fossil fuel release, carbon cycle approximations, and the implications of revisions in fossil fuel patterns required to maintain atmospheric CO 2 levels below a chosen threshold. In general, we find that with a judiciously selected exponential fossil fuel release rate, and with a constant airborn fraction, we can estimate atmospheric CO 2 growth over the next 50 years based on essentially surprise free scenarios. Resource depletion effects must be included for projections beyond about 50 years, and on this time frame the constant airborne fraction approximation has to be questioned as well (especially in later years when the fossil fuel use begins to taper off). For projections for over 100 years, both energy demand scenarios and currently available carbon cycle models have sufficient uncertainties that atmospheric CO 2 levels derived from them are not much better than guesses

  5. Unexpected observations of muons from Cygnus X-3

    International Nuclear Information System (INIS)

    Elbert, J.W.

    1986-01-01

    One surface experiment (Kiel) and two underground experiments (Soudan and Mt. Blanc) have detected unexpectedly large fluxes of cosmic ray muons from the approximate direction of Cygnus X-3, with signals showing the precise period of the system. The muon signals cannot be produced by any known type of elementary particle unless unexpected processes are involved

  6. Joint release rate estimation and measurement-by-measurement model correction for atmospheric radionuclide emission in nuclear accidents: An application to wind tunnel experiments.

    Science.gov (United States)

    Li, Xinpeng; Li, Hong; Liu, Yun; Xiong, Wei; Fang, Sheng

    2018-03-05

    The release rate of atmospheric radionuclide emissions is a critical factor in the emergency response to nuclear accidents. However, there are unavoidable biases in radionuclide transport models, leading to inaccurate estimates. In this study, a method that simultaneously corrects these biases and estimates the release rate is developed. Our approach provides a more complete measurement-by-measurement correction of the biases with a coefficient matrix that considers both deterministic and stochastic deviations. This matrix and the release rate are jointly solved by the alternating minimization algorithm. The proposed method is generic because it does not rely on specific features of transport models or scenarios. It is validated against wind tunnel experiments that simulate accidental releases in a heterogonous and densely built nuclear power plant site. The sensitivities to the position, number, and quality of measurements and extendibility of the method are also investigated. The results demonstrate that this method effectively corrects the model biases, and therefore outperforms Tikhonov's method in both release rate estimation and model prediction. The proposed approach is robust to uncertainties and extendible with various center estimators, thus providing a flexible framework for robust source inversion in real accidents, even if large uncertainties exist in multiple factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. ALMA Long Baseline Observations of the Dynamical Atmospheres of AGB Stars

    Science.gov (United States)

    Vlemmings, Wouter

    2018-04-01

    I will present the current status of ALMA long baseline observations of W Hya, R Leo, R Dor and Mira. We have recently obtained band 4, 6 and 7 observations of the line and continuum emission tracing the temperature and dynamics in their extended atmosphere. Our preliminary analysis confirms our previous detection of a hotspot on W Hya, and reveals unexpected lines in most of the sources, as well as possible fast rotation in the atmopshere of one of the stars. The observations show the unique power of ALMA in observing the extended stellar atmospheres.

  8. The annual averaged atmospheric dispersion factor and deposition factor according to methods of atmospheric stability classification

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Sun; Jeong, Hyo Joon; Kim, Eun Han; Han, Moon Hee; Hwang, Won Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-09-15

    This study analyzes the differences in the annual averaged atmospheric dispersion factor and ground deposition factor produced using two classification methods of atmospheric stability, which are based on a vertical temperature difference and the standard deviation of horizontal wind direction fluctuation. Daedeok and Wolsong nuclear sites were chosen for an assessment, and the meteorological data at 10 m were applied to the evaluation of atmospheric stability. The XOQDOQ software program was used to calculate atmospheric dispersion factors and ground deposition factors. The calculated distances were chosen at 400 m, 800 m, 1,200 m, 1,600 m, 2,400 m, and 3,200 m away from the radioactive material release points. All of the atmospheric dispersion factors generated using the atmospheric stability based on the vertical temperature difference were shown to be higher than those from the standard deviation of horizontal wind direction fluctuation. On the other hand, the ground deposition factors were shown to be same regardless of the classification method, as they were based on the graph obtained from empirical data presented in the Nuclear Regulatory Commission's Regulatory Guide 1.111, which is unrelated to the atmospheric stability for the ground level release. These results are based on the meteorological data collected over the course of one year at the specified sites; however, the classification method of atmospheric stability using the vertical temperature difference is expected to be more conservative.

  9. Upper atmosphere tidal oscillations due to latent heat release in the tropical troposphere

    Directory of Open Access Journals (Sweden)

    J. M. Forbes

    1997-09-01

    Full Text Available Latent heat release associated with tropical deep convective activity is investigated as a source for migrating (sun-synchronous diurnal and semidiurnal tidal oscillations in the 80–150-km height region. Satellite-based cloud brightness temperature measurements made between 1988 and 1994 and averaged into 3-h bins are used to determine the annual- and longitude-average local-time distribution of rainfall rate, and hence latent heating, between ±40° latitude. Regional average rainfall rates are shown to be in good agreement with climatological values derived from surface rain gauge data. A global linearized wave model is used to estimate the corresponding atmospheric perturbations in the mesosphere/lower thermosphere (80–150 km resulting from upward-propagating tidal components excited by the latent heating. The annual-average migrating diurnal and semidiurnal components achieve velocity and temperature amplitudes of order 10–20 m s–1 and 5–10 K, respectively, which represent substantial contributions to the dynamics of the region. The latent heat forcing also shifts the phase (local solar time of maximum of the semidiurnal surface pressure oscillation from 0912 to 0936 h, much closer to the observed value of 0944 h.

  10. Advanced Atmospheric Ensemble Modeling Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Chiswell, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kurzeja, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Maze, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Viner, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Werth, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-29

    Ensemble modeling (EM), the creation of multiple atmospheric simulations for a given time period, has become an essential tool for characterizing uncertainties in model predictions. We explore two novel ensemble modeling techniques: (1) perturbation of model parameters (Adaptive Programming, AP), and (2) data assimilation (Ensemble Kalman Filter, EnKF). The current research is an extension to work from last year and examines transport on a small spatial scale (<100 km) in complex terrain, for more rigorous testing of the ensemble technique. Two different release cases were studied, a coastal release (SF6) and an inland release (Freon) which consisted of two release times. Observations of tracer concentration and meteorology are used to judge the ensemble results. In addition, adaptive grid techniques have been developed to reduce required computing resources for transport calculations. Using a 20- member ensemble, the standard approach generated downwind transport that was quantitatively good for both releases; however, the EnKF method produced additional improvement for the coastal release where the spatial and temporal differences due to interior valley heating lead to the inland movement of the plume. The AP technique showed improvements for both release cases, with more improvement shown in the inland release. This research demonstrated that transport accuracy can be improved when models are adapted to a particular location/time or when important local data is assimilated into the simulation and enhances SRNL’s capability in atmospheric transport modeling in support of its current customer base and local site missions, as well as our ability to attract new customers within the intelligence community.

  11. Simulation of atmospheric dispersion of radioactivity from the Chernobyl accident

    International Nuclear Information System (INIS)

    Lange, R.; Sullivan, T.J.; Gudiksen, P.H.

    1989-07-01

    Measurements of airborne radioactivity over Europe, Japan, and the United States indicated that the release from the Chernobyl reactor accident in the Soviet Union on April 26, 1986 contained a wide spectrum of fission up to heights of 7 km or more within a few days after the initial explosion. This high-altitude presence of radioactivity would in part be attributable to atmospheric dynamics factors other than the thermal energy released in the initial explosion. Indications were that two types of releases had taken place -- an initial powerful explosion followed by days of a less energetic reactor fire. The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) utilized three-dimensional atmospheric dispersion models to determine the characteristics of the source term (release) and the evolution of the spatial distributions of the airborne radioactivity as it was transported over Europe and subsequently over the northern hemisphere. This paper describes the ARAC involvement and the results of the hemispheric model calculations which graphically depict the extensive dispersal of radioactivity. 1 fig

  12. Cognitive Readiness: Preparing for the Unexpected

    National Research Council Canada - National Science Library

    Fletcher, J. D

    2004-01-01

    .... Anticipated operational requirements can be decomposed into specific tasks, conditions, and standards, but how should individuals, teams, and units prepare for the unexpected, which, by definition...

  13. Dose estimation models for environmental tritium released from fusion facilities

    International Nuclear Information System (INIS)

    Murata, Mikio

    1993-01-01

    Various mathematical models are being developed to predict the behavior of HT released to the natural environment and their consequent impact. This report outlines models and the major findings of HT field release studies in France and Canada. The models are constructed to incorporate the key processes thought to be responsible for the formation of atmospheric HTO from a release of HT. It has been established from the experiments that HT oxidized in surface soil is incorporated almost entirely into soil water as HTO. This tritium may be reemitted to the atmosphere in the form of HTO through exchange of soil and atmospheric moisture as well as through the bulk water mass flux from the soil the atmosphere due to evaporation and transpiration. The direct conversion of HT to HTO in air and direct uptake of HT by vegetation are expected to be negligible for the time and space scales of interest in considering short duration releases. HTO emitted to the atmosphere is can further exchange with soil and vegetation water. Validation of these models against experimental data is conducted to demonstrate their credibility. It may be concluded that further laboratory and field works are needed in order to develop a sufficiently good understanding of the dependence of the key processes on environmental factors (including diurnal cycling and seasonality) to allow the rates of the processes to be predicted from a knowledge of environmental conditions. (author)

  14. Heat release rate from the combustion of uranium

    International Nuclear Information System (INIS)

    Solbrig, C.W.

    1995-01-01

    Fuel treatment is planned at the Argonne National Laboratory on EBR-II spent fuel. The electrochemical treatment process is carried out in a cell with an argon atmosphere to prevent any reaction. The amount of fuel processed at any time is limited by the amount of energy which could be released by metal combustion if air is inadvertently allowed into the cell since the heat release would increase the cell pressure. The cell pressure is required to be below atmospheric even if combustion occurs to ensure no cell gas/aerosol is released to the environment. Metal fires can release large amounts of heat. In certain configurations such as fine particulate, metal can be pyrophoric at room temperature. When the metal is a nuclear fuel, it is important to be able to predict the reaction/heat release rate if the metal is inadvertently exposed to air. A realistic combustion model is needed to predict heat release rates for the many different flow and transport configurations which exist in the various fuel processing steps. A model for the combustion of uranium is developed here which compares satisfactorily to experimental data

  15. 77 FR 21389 - Unexpected Urgent Refugee and Migration Needs

    Science.gov (United States)

    2012-04-10

    ... April 3, 2012 Unexpected Urgent Refugee and Migration Needs Memorandum for the Secretary of State By the... 2(c)(1) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended, (22 U.S.C... United States Emergency Refugee and Migration Assistance Fund, for the purpose of meeting unexpected and...

  16. Analysis of accidental UF6 releases

    International Nuclear Information System (INIS)

    Fan Yumao; Tan Rui; Gao Qifa

    2012-01-01

    As interim substance in the nuclear fuel enrichment process, Uranium Hexafluoride (UF 6 ) is widely applied in nuclear processing, enrichment and fuel fabrication plants. Because of its vivid chemical characteristics and special radiological hazard and chemical toxicity, great attention must be paid to accident of UF 6 leakage. The chemical reactions involved in UF 6 release processes were introduced, therewith potential release styles, pathways and characteristics of diffusion were analyzed. The results indicated that the accidental release process of UF 6 is not a simple passive diffusion. So, specific atmospheric diffusion model related to UF 6 releases need be used in order to analyze and evaluate accurately the accidental consequences. (authors)

  17. Who's afraid of atmospheres (and of their authority?

    Directory of Open Access Journals (Sweden)

    Tonino Griffero

    2014-07-01

    Full Text Available An atmosphere possesses and exercises authority over the perceiver and his felt-body. This authority (a ‘numinous’ one exists in the proper sense only when it prevails over our resistance and we cannot access a further critical level. This is because an atmosphere that I feel externally, as poured out into the surrounding space, is mine not because I possess it, but because it concerns me.Its normativity, moreover, is not so much discreet but rather loosely diffused into a situation and yet it is able to inhibit any critical distance in those who come across it, especially if unexpectedly. This atmospherological approach implies of course a reflection about the ethical consequences of our ‘necessary’ felt-bodily feelings. Even if the manipulative appearance is implicit in every practice that generates an atmosphere, it’s true thatonly by acquiring a better atmospheric ‘competence’ (both as thinkers and as perceivers we can really learn how not to be grossly manipulated. An atmosphere is maybe less manipulative when it allowsaquick alternation between an uncritical-pathicimmersion and a critical-rational emersion, namely, between an emotional mood and a more analytical one.

  18. Methods for conduct of atmospheric tracer studies at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Stone, D J.M.; Pascoe, J H [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Division

    2000-07-01

    A perfluorocarbon atmospheric tracer system has been developed to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. This report discusses the tracer release, sampling and analysis methods.

  19. CRUNCH, Dispersion Model for Continuous Dense Vapour Release in Atmosphere

    International Nuclear Information System (INIS)

    Jagger, S.F.

    1987-01-01

    ambient atmospheric turbulence, and to follow the dispersion processes down to low concentrations, especially important for toxic gases, a virtual source passive dispersion model is fitted to the slumping plume. 2 - Restrictions on the complexity of the problem: Acceleration of the plume to the wind velocity is not considered, since an analysis of inertial effects has shown that the time for which these are important is short, compared to the dispersion time. Additionally, wind shear effects on cloud structure are not included; for a puff release producing a cloud of finite extent, this may not be valid but for a plume, extending to large downwind distances, they can be argued to have only a minor influence at the advancing front

  20. Contact: Releasing the news

    Science.gov (United States)

    Pinotti, Roberto

    The problem of mass behavior after man's future contacts with other intelligences in the universe is not only a challenge for social scientists and political leaders all over the world, but also a cultural time bomb as well. In fact, since the impact of CETI (Contact with Extraterrestrial Intelligence) on human civilization, with its different cultures, might cause a serious socio-anthropological shock, a common and predetermined worldwide strategy is necessary in releasing the news after the contact, in order to keep possible manifestations of fear, panic and hysteria under control. An analysis of past studies in this field and of parallel historical situations as analogs suggests a definite "authority crisis" in the public as a direct consequence of an unexpected release of the news, involving a devastating "chain reaction" process (from both the psychological and sociological viewpoints) of anomie and maybe the collapse of today's society. The only way to prevent all this is to prepare the world's public opinion concerning contact before releasing the news, and to develop a long-term strategy through the combined efforts of scientists, political leaders, intelligence agencies and the mass media, in order to create the cultural conditions in which a confrontation with ETI won't affect mankind in a traumatic way. Definite roles and tasks in this multi-level model are suggested.

  1. Improved emergency elevated air release for simplified PWR

    International Nuclear Information System (INIS)

    Naitoh, T.; Bruce, R.A.; Hirota, K.; Tajiri, Y.

    1992-01-01

    In developing the application of the simplified PWR in Japan, one of the most important areas is to limit post-accident site boundary whole body dose. In addressing this, the concept of Emergency Passive Air Filtration System (EPAFS) and it's feasibility is developed. The efficiency of charcoal filtering and the atmospheric diffusion effect of an elevated air release are important for dose reduction. The performance of these functions was evaluated by confirmatory testing. The test results confirmed a 99 percent efficiency of charcoal filter and an atmospheric diffusion effect higher than that of a conventional plant. The Emergency Passive Air Filtration System (EPAFS) and the atmospheric diffusion effect of elevated air release contribute to making the calculated post-accident site boundary whole body dose of simplified PWR as low as that of the conventional Japanese PWR plant. (author)

  2. Model for absorption and release of gaseous materials by forest canopies

    International Nuclear Information System (INIS)

    Murphy, C.E. Jr.

    1976-01-01

    A model of the physical processes defining the absorption and release of materials by a forest canopy has been developed. The model deals with the turbulent transport of gaseous materials in the surface boundary layer near the canopy, the turbulent transport in the canopy atmosphere, the transport through the boundary layer near the leaf and soil surface, and the solution of the gaseous materials in intracellular fluids and subsequent diffusion into the leaf cells. The model is used to simulate the uptake of molecular tritium by the forest canopy and the subsequent release of tritiated water. Results of dynamic simulations of tritium uptake and release are compared with data collected at the time of a release of molecular tritium to the atmosphere

  3. Graphic displays on PCs of gaseous diffusion models of radionuclide releases to the atmosphere

    International Nuclear Information System (INIS)

    Campo Ortega, E. del

    1993-01-01

    The well-known MESOI program has been modified and improved to adapt it to a PC/AT with VGA colour monitor. Far from losing any of its powerful characteristics to calculate the transport, diffusion, deposition and decay of gaseous radioactive effluents discharged to the atmosphere, it has been enhanced to allow graphic viewing of concentrations, wind speed and direction and puff locations in colour, all on a background map of the site. The background covers a 75 x 75 km square and has a graphic grid density of 421 x 421 pixels. This means that effluent concentration is represented approximately every 170 metres in the 'clouded-area'. Among the modifications and enhancements made, the following are of particular interest: 1. A new subroutine called NUBE has been added, which calculates the distribution of effluent concentration of activity in a grid of 421 x 421 pixels. 2. Several subroutines have been added to obtain graphic displays and printouts of the cloud, wind field and puff locations. 3. Graphic display of the geographic plane of the area surrounding the effluent release point. 4. Off-line preparation of meteorological and topographical data files necessary for program execution. (author)

  4. Nuclear risk from atmospheric dispersion in Northern Europe - Summary Report

    DEFF Research Database (Denmark)

    Lauritzen, Bent

    The objective of the NordRisk II project has been to derive practical means for assessing the risks from long-range atmospheric dispersion of radioac-tive materials. An atlas over different atmospheric dispersion and deposi-tion scenarios has been developed using historical numerical weather pre......-diction (NWP) model data. The NWP model data covers three years span-ning the climate variability associated with the North Atlantic Oscillation, and the atlas considers radioactive releases from 16 release sites in and near the Nordic countries. A statistical analysis of the long-range disper......-sion and deposition patterns is undertaken to quantify the mean dispersion and deposition as well as the variability. Preliminary analyses show that the large-scale atmospheric dispersion and deposition is near-isotropic, irrespective of the release site and detailed climatology, and allows for a simple...

  5. Underground Nuclear Explosions and Release of Radioactive Noble Gases

    Science.gov (United States)

    Dubasov, Yuri V.

    2010-05-01

    Over a period in 1961-1990 496 underground nuclear tests and explosions of different purpose and in different rocks were conducted in the Soviet Union at Semipalatinsk and anovaya Zemlya Test Sites. A total of 340 underground nuclear tests were conducted at the Semipalatinsk Test Site. One hundred seventy-nine explosions (52.6%) among them were classified as these of complete containment, 145 explosions (42.6%) as explosions with weak release of radioactive noble gases (RNG), 12 explosions (3.5%) as explosions with nonstandard radiation situation, and four excavation explosions with ground ejection (1.1%). Thirty-nine nuclear tests had been conducted at the Novaya Zemlya Test Site; six of them - in shafts. In 14 tests (36%) there were no RNG release. Twenty-three tests have been accompanied by RNG release into the atmosphere without sedimental contamination. Nonstandard radiation situation occurred in two tests. In incomplete containment explosions both early-time RNG release (up to ~1 h) and late-time release from 1 to 28 h after the explosion were observed. Sometimes gas release took place for several days, and it occurred either through tunnel portal or epicentral zone, depending on atmospheric air temperature.

  6. A progress report on the carbon dominated atmosphere white dwarfs

    International Nuclear Information System (INIS)

    Dufour, P; Liebert, J; Swift, B; Sukhbold, T; Fontaine, G

    2009-01-01

    Recently, Dufour et al. (2007) reported the unexpected discovery that a few white dwarfs found in the Sloan Digital Sky Survey had an atmosphere dominated by carbon with little or no trace of hydrogen and helium. Here we present a progress report on these new objects based on new high signal-to-noise follow-up spectroscopic observations obtained at the 6.5m MMT telescope on Mount Hopkins, Arizona.

  7. Results of experimental study on detritiation of atmosphere in large space

    International Nuclear Information System (INIS)

    Kobayashi, Kazuhiro; Hayashi, Takumi; Iwai, Yasunori; Nishi, Masataka

    2001-01-01

    In order to obtain data on tritium removal from the atmosphere of a room, which is needed for designing a reliable effective atmosphere detritiation system in a fusion reactor and for detailed analysis on its safety, intentional tritium release experiments have been carried out in a controlled space called Caisson under various atmosphere conditions at the Tritium Process Laboratory (TPL) in Japan Atomic Energy Research Institute (JAERI). In case there is no tritiated water vapor in the released tritium gas, tritium was ideally removed by constant ventilation in spite of atmospheric conditions and residence time. On the other hand, when tritiated water vapor existed in the released tritium, residual contamination on the wall of the Caisson was detected and it was found that it depended on the initial humidity in the Caisson. This tritium removal behavior was successfully analyzed by considering the adsorption and desorption reaction rates of tritiated water on the wall by the constant ventilation

  8. Atmospheric diffusion study and its application to nuclear energy

    International Nuclear Information System (INIS)

    Chino, Masamichi

    1990-01-01

    The report reviews studies on atmospheric diffusion of radioactive substances released from a smokestack. Smoke containing radioactive substances, or radioactive plume, diffuses into air while being affected by atmospheric turbulent flows in various ways depending on the scale of the plume. The diffusion of a radioactive plume released from a smokestack is discussed first, focusing on the diffusion process in the vicinity of the smokestack, in the atmospheric boundary layer and in the troposphere. Many theoretical studies have been conducted by using the Gaussian plume model, though it is too simple to take into account the topographic effects and unstationary atmospheric conditions. Various numerical calculation models (designed for numerical calculation by a computer) have recently been developed, particularly for the implementation of environmental impact evaluation. Diagnostic and forecast type models are available for atmospheric air flow calculation. Other models available for diffusion analysis include the puff model, segment model, PIC (particle in cell)model, and random walk model. (N.K.)

  9. Releases of UF6 to the atmosphere after a potential fire in a cylinder storage yard

    International Nuclear Information System (INIS)

    Lombardi, D.A.; Williams, W.R.; Anderson, J.C.

    1997-01-01

    Uranium hexafluoride (UF 6 ), a toxic material, is stored in just over 6200 cylinders at the K-25 site in Oak Ridge, Tennessee. The safety analysis report (SAR) for cylinder yard storage operations at the plant required the development of accident scenarios for the potential release of UF 6 to the atmosphere. In accordance with DOE standards and guidance, the general approach taken in this SAR was to examine the functions and contents of the cylinder storage yards to determine whether safety-significant hazards were present for workers in the immediate vicinity, workers on-site, the general public off-site, or the environment. and to evaluate the significance of any hazards that were found. A detailed accident analysis was performed to determine a set of limiting accidents that have potential for off-site consequences. One of the limiting accidents identified in the SAR was the rupture of a cylinder engulfed in a fire

  10. [Development of the unexpected reality scale for childcare training].

    Science.gov (United States)

    Matsuda, Yuko; Shitara, Saeko; Hamada, Shoko

    2016-10-01

    This study aimed to develop a scale for unexpected reality for childcare training (Study 1) and examine the change and influence it exerts on the efficacy of preschool teachers (Study 2). In Study 1, the sample consisted of 571 university and junior college students enrolled in a childcare course. After exploratory factor analysis, four factors were extracted: “actual feelings for childcare as a field of study,” “difficulties faced during involvement with children,” “negative aspects of the childcare worker,” and “severity of work.” The study’s scale was shown to be internally consistent and valid. In Study 2, the sample consisted of 122 junior college students enrolled in a childcare course. The results showed that the high-scoring groups of each unexpected reality subscales experienced less unexpected reality in the subsequent training session. Moreover, the results of multiple regression showed that preschool teacher efficacy was predicted positively by “actual feelings for childcare as a field of study” and negatively by “difficulties faced during involvement with children.” Thus, we suggest that for effective pre- and post-guidance of childcare training, unexpected realities should be considered.

  11. Controlled release of bioactive PDGF-AA from a hydrogel/nanoparticle composite.

    Science.gov (United States)

    Elliott Donaghue, Irja; Shoichet, Molly S

    2015-10-01

    Polymer excipients, such as low molar mass poly(ethylene glycol) (PEG), have shown contradictory effects on protein stability when co-encapsulated in polymeric nanoparticles. To gain further insight into these effects, platelet-derived growth factor (PDGF-AA) was encapsulated in polymeric nanoparticles with vs. without PEG. PDGF-AA is a particularly compelling protein, as it has been demonstrated to promote cell survival and induce the oligodendrocyte differentiation of neural stem/progenitor cells (NSPCs) both in vitro and in vivo. Here we show, for the first time, the controlled release of bioactive PDGF-AA from an injectable nanoparticle/hydrogel drug delivery system (DDS). PDGF-AA was encapsulated, with high efficiency, in poly(lactide-co-glycolide) nanoparticles, and its release from the drug delivery system was followed over 21 d. Interestingly, the co-encapsulation of low molecular weight poly(ethylene glycol) increased the PDGF-AA loading but, unexpectedly, accelerated the aggregation of PDGF-AA, resulting in reduced activity and detection by enzyme-linked immunosorbent assay (ELISA). In the absence of PEG, released PDGF-AA remained bioactive as demonstrated with NSPC oligodendrocyte differentiation, similar to positive controls, and significantly different from untreated controls. This work presents a novel delivery method for differentiation factors, such as PDGF-AA, and provides insights into the contradictory effects reported in the literature of excipients, such as PEG, on the loading and release of proteins from polymeric nanoparticles. Previously, the polymer poly(ethylene glycol) (PEG) has been used in many biomaterials applications, from surface coatings to the encapsulation of proteins. In this work, we demonstrate that, unexpectedly, low molecular weight PEG has a deleterious effect on the release of the encapsulated protein platelet-derived growth factor AA (PDGF-AA). We also demonstrate release of bioactive PDGF-AA (in the absence of PEG

  12. Verification of atmospheric diffusion models with data of atmospheric diffusion experiments

    International Nuclear Information System (INIS)

    Hato, Shinji; Homma, Toshimitsu

    2009-02-01

    The atmospheric diffusion experiments were implemented by Japan Atomic Energy Research Institute (JAERI) around Mount Tsukuba in 1989 and 1990, and the tracer gas concentration were monitored. In this study, the Gauss Plume Model and RAMS/HYPACT that are meteorological forecast code and atmospheric diffusion code with detailed physical law are made a comparison between monitored concentration. In conclusion, the Gauss Plume Model is better than RAM/HYPACT even complex topography if the estimation is around tens of kilometer form release point and the change in weather is constant for short time. This reason is difference of wind between RAMS and observation. (author)

  13. Structural imaging biomarkers of sudden unexpected death in epilepsy.

    Science.gov (United States)

    Wandschneider, Britta; Koepp, Matthias; Scott, Catherine; Micallef, Caroline; Balestrini, Simona; Sisodiya, Sanjay M; Thom, Maria; Harper, Ronald M; Sander, Josemir W; Vos, Sjoerd B; Duncan, John S; Lhatoo, Samden; Diehl, Beate

    2015-10-01

    Sudden unexpected death in epilepsy is a major cause of premature death in people with epilepsy. We aimed to assess whether structural changes potentially attributable to sudden death pathogenesis were present on magnetic resonance imaging in people who subsequently died of sudden unexpected death in epilepsy. In a retrospective, voxel-based analysis of T1 volume scans, we compared grey matter volumes in 12 cases of sudden unexpected death in epilepsy (two definite, 10 probable; eight males), acquired 2 years [median, interquartile range (IQR) 2.8] before death [median (IQR) age at scanning 33.5 (22) years], with 34 people at high risk [age 30.5 (12); 19 males], 19 at low risk [age 30 (7.5); 12 males] of sudden death, and 15 healthy controls [age 37 (16); seven males]. At-risk subjects were defined based on risk factors of sudden unexpected death in epilepsy identified in a recent combined risk factor analysis. We identified increased grey matter volume in the right anterior hippocampus/amygdala and parahippocampus in sudden death cases and people at high risk, when compared to those at low risk and controls. Compared to controls, posterior thalamic grey matter volume, an area mediating oxygen regulation, was reduced in cases of sudden unexpected death in epilepsy and subjects at high risk. The extent of reduction correlated with disease duration in all subjects with epilepsy. Increased amygdalo-hippocampal grey matter volume with right-sided changes is consistent with histo-pathological findings reported in sudden infant death syndrome. We speculate that the right-sided predominance reflects asymmetric central influences on autonomic outflow, contributing to cardiac arrhythmia. Pulvinar damage may impair hypoxia regulation. The imaging findings in sudden unexpected death in epilepsy and people at high risk may be useful as a biomarker for risk-stratification in future studies. The Author (2015). Published by Oxford University Press on behalf of the Guarantors of

  14. Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

    International Nuclear Information System (INIS)

    1983-06-01

    This report is the second in a series concerned with the evaluation of the consequences to the public of an accidental release of hydrogen sulphide (H 2 S) to the atmosphere following a pipe or pressure envelope failure, or some other process upset, at a heavy water plant. It consists of documentation of the code GASPROB, which has been developed to provide consequence probabilities for a range of postulated releases. The code includes mathematical simulations of initial gas behaviour upon release to the atmosphere, such as gravitational settling of a cold release and the rise of jets and flares, subsequent atmospheric dispersion under a range of weather conditions, and the toxic effects on the exposed population. The code makes use of the site-specific dispersion climatology, topography and population distribution, as well as the probabilistic lethal dose data for the released gas. Output for a given postulated release can be provided in terms of the concentration of the gas at ground level around the point of release, projected numbers of fatalities within specified areas and the projected total fatalities regardless of location. This report includes a general description of GASPROB, and specifics of the code structure, the function of each subroutine, input and output data, and the permanent data files established. Three appendices to the report contain a complete code listing, detailed subroutine descriptions and a sample output

  15. Diffusive retention of atmospheric gases in chert

    Science.gov (United States)

    Pettitt, E.; Cherniak, D. J.; Watson, E. B.; Schaller, M. F.

    2016-12-01

    Throughout Earth's history, the volatile contents (N2, CO2, Ar) of both deep and shallow terrestrial reservoirs has been dynamic. Volatiles are important chemical constituents because they play a significant role in regulating Earth's climate, mediating the evolution of complex life, and controlling the properties of minerals and rocks. Estimating levels of atmospheric volatiles in the deep geological past requires interrogation of materials that have acquired and retained a chemical memory from that time. Cherts have the potential to trap atmospheric components during formation and later release those gases for analysis in the laboratory. However, cherts have been underexploited in this regard, partly because their ability to retain a record of volatile components has not been adequately evaluated. Before cherts can be reliably used as indicators of past levels of major atmospheric gases, it is crucial that we understand the diffusive retentiveness of these cryptocrystalline silica phases. As the first step toward quantifying the diffusivity and solubility of carbon dioxide and nitrogen in chert, we have performed 1-atmosphere diffusive-uptake experiments at temperatures up to 450°C. Depth profiles of in-diffusing gases are measured by nuclear reaction analysis (NRA) to help us understand the molecular-scale transport of volatiles and thus the validity of using chert-bound volatiles to record information about Earth history. Data collected to date suggest that at least some cherts are ideal storage containers and can retain volatiles for a geologically long time. In addition to these diffusion experiments, preliminary online-crush fast-scan measurements using a quadrupole mass spectrometer indicate that atmospheric volatiles are released upon crushing various chert samples. By coupling such volatile-release measurements made by mass spectrometry with diffusion experiments, we are uniquely able to address the storage and fidelity of volatiles bound in crustal

  16. Emissions of the corrosion radionuclides in an atmosphere

    International Nuclear Information System (INIS)

    Vardanyan, M.

    2010-01-01

    In area of Armenian nuclear power plant location, in atmospheric air in majority of cases log two technogenic radionuclides: l 37 C s and 9 0 S r. Presence of these radionuclides basically is caused by global fall out (consequences of tests of the nuclear weapon and Chernobyl NPP accident), whose contribution to the contents of these radionuclides in atmosphere is incomparably greater, than emissions from the NPP. However there are some cases when in an atmosphere are registered the technogenic radionuclides, caused by emissions from NPP. In the present work such case is considered. Gas-aerosol releases of NPP in the atmosphere are carefully purified by means of various high-efficiency filters and gas-cleaning systems. Nevertheless, one should forecast and measure, the possible impact of these releases on the environment in the regions surrounding the NPP. Radioactive releases of the Armenian NPP (ANPP) contain the set of radionuclides characteristic for NPPs of this type. They may be divided into three groups: 1 31 I , 1 37 C s, 1 34 C s, 9 0 S r and 8 9 S r fission fragments, isotopes of noble gases krypton and xenon and other radionuclides; corrosion originated radionuclides: 6 0 C o, 1 10m A g, 5 4 M n, 5 l C r and others; activation products of the heat-transfer agent itself. It should be noted that the amount of radioactive materials released in the environment by the ANPP during the whole period of its operation was much lower than the admissible quantities specified in the corresponding legal documents (RSN, NPPSP) acting in Armenia, which are practically identical to the internationally accepted norms. The amounts of releases and their radionuclides composition for the ANPP are given

  17. Assessing the impact of atmospheric chemistry on the fate, transport, and transformation of adulticides in an urban atmosphere

    Science.gov (United States)

    Guberman, S.; Yoon, S.; Guagenti, M. C.; Sheesley, R. J.; Usenko, S.

    2017-12-01

    Urban areas are literal hot spots of mosquito-borne disease transmission and air pollution during the summer months. Public health authorities release aerosolized adulticides to target adult mosquitoes directly in to the atmosphere to control mosquito populations and reduce the threat of diseases (e.g. Zika). Permethrin and malathion are the primary adulticides for controlling adult mosquito populations in Houston, TX and are typically sprayed at night. After being released into the atmosphere adulticides are subject to atmospheric oxidation initiated by atmospheric oxidants (e.g. O3 and NO3) which are driven by anthropogenic air pollutants (e.g. NOx; NO and NO2). Particulate matter (PM) samples were measured at both application and downwind locations. Sampling sites were determined using the combination of atmospheric plume transport models and adulticide application data provided by Harris County Public Health Mosquito Division. Atmospheric PM samples were taken using a Mobile Laboratory, equipped with total suspended PM and PM2.5 (PM with diameter Interestingly, during malathion-use periods, atmospheric malaoxon concentrations measured in the PM2.5 samples were similar to corresponding TSP samples. This suggests that the majority of the malathion (and malaoxon) was associated with fine PM. During permethrin-use periods, atmospheric permethrin concentrations measured in the PM2.5 samples were an order and half lower in magnitude. This suggests that permethrin may be undergoing less volatilization into the gas phase after application as compared to malathion (and or malaoxon). Unlike permethrin, malathion was not sprayed with a carrier or a synergistic compound. As a result, malathion may be more prone to volatilization. The atmospheric oxidation and migration to fine PM may result in decreased efficacy and increase atmospheric transport, both of which have environmental and human health consequences.

  18. Verification of atmospheric diffusion models using data of long term atmospheric diffusion experiments

    International Nuclear Information System (INIS)

    Tamura, Junji; Kido, Hiroko; Hato, Shinji; Homma, Toshimitsu

    2009-03-01

    Straight-line or segmented plume models as atmospheric diffusion models are commonly used in probabilistic accident consequence assessment (PCA) codes due to cost and time savings. The PCA code, OSCAAR developed by Japan Atomic Energy Research Institute (Present; Japan Atomic Energy Agency) uses the variable puff trajectory model to calculate atmospheric transport and dispersion of released radionuclides. In order to investigate uncertainties involved with the structure of the atmospheric dispersion/deposition model in OSCAAR, we have introduced the more sophisticated computer codes that included regional meteorological models RAMS and atmospheric transport model HYPACT, which were developed by Colorado State University, and comparative analyses between OSCAAR and RAMS/HYPACT have been performed. In this study, model verification of OSCAAR and RAMS/HYPACT was conducted using data of long term atmospheric diffusion experiments, which were carried out in Tokai-mura, Ibaraki-ken. The predictions by models and the results of the atmospheric diffusion experiments indicated relatively good agreements. And it was shown that model performance of OSCAAR was the same degree as it of RAMS/HYPACT. (author)

  19. Unexpected O and O3 production in the effluent of He/O2 microplasma jets emanating into ambient air

    International Nuclear Information System (INIS)

    Ellerweg, D; Von Keudell, A; Benedikt, J

    2012-01-01

    Microplasma jets are commonly used to treat samples in ambient air. The effect of admixing air into the effluent may severely affect the composition of the emerging species. Here, the effluent of a He/O 2 microplasma jet has been analyzed in a helium and in an air atmosphere by molecular beam mass spectrometry. First, the composition of the effluent in air was recorded as a function of the distance to determine how fast air admixes into the effluent. Then, the spatial distribution of atomic oxygen and ozone in the effluent was recorded in ambient air and compared with measurements in a helium atmosphere. Additionally, a fluid model of the gas flow with reaction kinetics of reactive oxygen species in the effluent was constructed. In ambient air, the O density declines only slightly faster with distance compared with a helium atmosphere. In contrast, the O 3 density in ambient air increases significantly faster with distance compared with a helium atmosphere. This unexpected behavior cannot be explained by simple recombination reactions of O atoms with O 2 molecules. A reaction scheme involving the reaction of plasma-produced excited O 2 * species of unknown identity with ground state O 2 molecules is proposed as a possible explanation for these observations. (paper)

  20. Unexpected marked seizure improvement in paediatric epilepsy surgery candidates

    DEFF Research Database (Denmark)

    Hoei-Hansen, Christina E; Mathiasen, René; Uldall, Peter

    2017-01-01

    PURPOSE: Epilepsy surgery is performed based on the assumption that medical refractory epilepsy will continue. Rarely seizure freedom occurs before surgery is performed, while the patient is being evaluated as an epilepsy surgery candidate. The aim of this study was to describe the number...... of children withdrawn from an epilepsy surgery programme due to unexpected seizure improvement. METHODS: We retrospectively studied 173 children under 18 years with medical refractory epilepsy referred for epilepsy surgery between 1996 and 2010. Medical records were reviewed in 2012 and 2015. RESULTS......: At the first evaluation point in 2012, 13 patients were withdrawn from the epilepsy surgery programme due to unexpected marked improvement. In 2015, 6 of them were still seizure free. They had unexpected seizure freedom due to change in AED treatment (n=3) or after a febrile episode (n=3). The mean number...

  1. Special Analysis: Atmospheric Dose Resulting from the Release of C14 from Reactor Moderator Deionizers in a Disposal Environment

    International Nuclear Information System (INIS)

    Hiergesell, Robert A.; Swingle, Robert F.

    2005-01-01

    The proposed action of disposing of 52 moderator deionizer vessels within the ILV was evaluated in this SA. In particular, a detailed analysis of the release of 14 C via the atmospheric pathway was conducted for these vessels since the major concern has been the nearly 20 Ci of 14 C that is associated with each vessel. The more rigorous evaluation of the atmospheric pathway for 14 C included incorporation of new information about the chemical availability of 14 C when disposed in a grout/cement encapsulation environment, as will be the case in the ILV. This information was utilized to establish the source term for a 1-D numerical model to simulate the diffusion of 14 CO 2 from the ILV Waste Zone to the land surface. The results indicate a peak surface emanation rate from the entire ILV of 1.42E-08 Ci/yr with an associated dose of only 3.83E-05 mrem/yr to the Maximally Exposed Individual (MEI) at 100m. The fact that the atmospheric pathway exposure for 14 C is controlled by chemical solubility limits for 14 C between the solid waste, pore water and pore vapor within the disposal environment rather than the absolute inventory suggests that the establishment of specific facility limits is inappropriate. With the relaxation of the atmospheric pathway restriction, the groundwater pathway becomes the more restrictive in terms of disposing 14 C or 14 C KB within the ILV. Since the resin-based 14 C of the 52 moderator deionizer vessels is highly similar to the 14 C KB waste form, the inventory from the 52 deionizer vessels is compared against the groundwater limits for that waste form. The small groundwater pathway fraction (1.14E-05) calculated for the proposed inventory of the 52 moderator deionizer vessels indicates that the proposed action will have an insignificant impact with respect to possible exposures via the groundwater pathway. This investigation recommends that there be no ILV Atmospheric pathway limit for 14 C and 14 C KB . Further, in the absence of an

  2. Atmospheric dispersion modeling: Challenges of the Fukushima Daiichi response

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Gayle [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nasstrom, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pobanz, Brenda [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, Kevin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vogt, Phil [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Aluzzi, Fernando [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homann, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-05-01

    In this research, the U.S. Department of Energy’s (DOE) National Atmospheric Release Advisory Center (NARAC) provided a wide range of predictions and analyses as part of the response to the Fukushima Daiichi Nuclear Power Plant accident including: daily Japanese weather forecasts and atmospheric transport predictions to inform planning for field monitoring operations and to provide U.S. government agencies with ongoing situational awareness of meteorological conditions; estimates of possible dose in Japan based on hypothetical U.S. Nuclear Regulatory Commission scenarios of potential radionuclide releases to support protective action planning for U.S. citizens; predictions of possible plume arrival times and dose levels at U.S. locations; and source estimation and plume model refinement based on atmospheric dispersion modeling and available monitoring data.

  3. Unexpected Translations in Urban Policy Mobility

    DEFF Research Database (Denmark)

    Zapata, Patrik; Zapata Campos, Maria José

    2015-01-01

    such as prototypes in order to travel. It was made mobile via relational sites or situations providing safe and accessible connections with Chureca residents. Paradoxically, these places also allowed extraordinary connections between actors located in different scales and spaces, facilitating unexpected local...

  4. Unexpected Translations in Urban Policy Mobility

    DEFF Research Database (Denmark)

    Zapata, Patrik; Zapata Campos, Maria José

    such as prototypes in order to travel. It was made mobile via relational sites or situations providing safe and accessible connections with Chureca residents. Paradoxically, these places also allowed extraordinary connections between actors located in different scales and spaces, facilitating unexpected local...

  5. Program report: FY 1976, Atmospheric and Geophysical Sciences Division, Physics Department

    International Nuclear Information System (INIS)

    Knox, J.B.; Orphan, R.C.

    1976-01-01

    The Atmospheric Release Advisory Capability (ARAC), with its central facility located at LLL, is meeting the long-term need for rapid and accurate regional dose-to-man estimates of nuclear material released as a result of accidents, operations, or terrorism acts. During the past two years, ARAC has been used in four potential WARMSPOT events and for one accidental release. Continuing research, in terms of new modeling techniques, simulation of regional tracer experiments, and other verification activities, support this capability. Emergency response is currently being upgraded to evaluate the consequences of atmospheric releases at selected nuclear facilities and for potential acts of nuclear terrorism anywhere in the Northern Hemisphere. Regional modeling was also applied in monitoring SO 2 -sulfate concentrations in the northeastern USA

  6. Expansion of ARAC for chemical releases

    International Nuclear Information System (INIS)

    Baskett, R.L.; Blair, M.D.; Foster, C.S.; Taylor, A.G.

    1997-01-01

    In 1996 the Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermore National Laboratory (LLNL) completed an effort to expand its national emergency response modeling system for chemical releases. Key components of the new capability include the integration of (1) an extensive chemical property database, (2) source modeling for tanks and evaporating pools, (3) denser-than-air dispersion, (4) public exposure guidelines, and (5) an interactive graphical user interface (GUI). Recent use and the future of the new capability are also discussed

  7. Radionuclide release rate inversion of nuclear accidents in nuclear facility based on Kalman filter

    International Nuclear Information System (INIS)

    Tang Xiuhuan; Bao Lihong; Li Hua; Wan Junsheng

    2014-01-01

    The rapidly and continually back-calculating source term is important for nuclear emergency response. The Gaussian multi-puff atmospheric dispersion model was used to produce regional environment monitoring data virtually, and then a Kalman filter was designed to inverse radionuclide release rate of nuclear accidents in nuclear facility and the release rate tracking in real time was achieved. The results show that the Kalman filter combined with Gaussian multi-puff atmospheric dispersion model can successfully track the virtually stable, linear or nonlinear release rate after being iterated about 10 times. The standard error of inversion results increases with the true value. Meanwhile extended Kalman filter cannot inverse the height parameter of accident release as interceptive error is too large to converge. Kalman filter constructed from environment monitoring data and Gaussian multi-puff atmospheric dispersion model can be applied to source inversion in nuclear accident which is characterized by static height and position, short and continual release in nuclear facility. Hence it turns out to be an alternative source inversion method in nuclear emergency response. (authors)

  8. Unexpected Expectations The Curiosities of a Mathematical Crystal Ball

    CERN Document Server

    Wapner, Leonard M

    2012-01-01

    Unexpected Expectations: The Curiosities of a Mathematical Crystal Ball explores how paradoxical challenges involving mathematical expectation often necessitate a reexamination of basic premises. The author takes you through mathematical paradoxes associated with seemingly straightforward applications of mathematical expectation and shows how these unexpected contradictions may push you to reconsider the legitimacy of the applications. The book requires only an understanding of basic algebraic operations and includes supplemental mathematical background in chapter appendices. After a history o

  9. Unexpected findings and promoting monocausal claims, a cautionary tale.

    Science.gov (United States)

    Copeland, Samantha Marie

    2017-10-01

    Stories of serendipitous discoveries in medicine incorrectly imply that the path from an unexpected observation to major discovery is straightforward or guaranteed. In this paper, I examine a case from the field of research about chronic fatigue syndrome (CFS). In Norway, an unexpected positive result during clinical care has led to the development of a research programme into the potential for the immunosuppressant drug rituximab to relieve the symptoms of CFS. The media and public have taken up researchers' speculations that their research results indicate a causal mechanism for CFS - consequently, patients now have great hope that 'the cause' of CFS has been found, and thus, a cure is sure to follow. I argue that a monocausal claim cannot be correctly asserted, either on the basis of the single case of an unexpected, although positive, result or on the basis of the empirical research that has followed up on that result. Further, assertion and promotion of this claim will have specific harmful effects: it threatens to inappropriately narrow the scope of research on CFS, might misdirect research altogether, and could directly and indirectly harm patients. Therefore, the CFS case presents a cautionary tale, illustrating the risks involved in drawing a theoretical hypothesis from an unexpected observation. Further, I draw attention to the tendency in contemporary clinical research with CFS to promote new research directions on the basis of reductive causal models of that syndrome. Particularly, in the case of CFS research, underdetermination and causal complexity undermine the potential value of a monocausal claim. In sum, when an unexpected finding occurs in clinical practice or medical research, the value of following up on that finding is to be found not in the projected value of a singular causal relationship inferred from the finding but rather in the process of research that follows. © 2016 John Wiley & Sons, Ltd.

  10. Model for Atmospheric Propagation of Spatially Combined Laser Beams

    Science.gov (United States)

    2016-09-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS MODEL FOR ATMOSPHERIC PROPAGATION OF SPATIALLY COMBINED LASER BEAMS by Kum Leong Lee September...MODEL FOR ATMOSPHERIC PROPAGATION OF SPATIALLY COMBINED LASER BEAMS 5. FUNDING NUMBERS 6. AUTHOR(S) Kum Leong Lee 7. PERFORMING ORGANIZATION NAME(S) AND...BLANK ii Approved for public release. Distribution is unlimited. MODEL FOR ATMOSPHERIC PROPAGATION OF SPATIALLY COMBINED LASER BEAMS Kum Leong Lee

  11. 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)

  12. 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)

  13. Assessment of consequences from airborne releases of radioactive material

    International Nuclear Information System (INIS)

    McGrath, P.E.; Blond, R.M.

    1976-01-01

    Over the past several years, the manner in which assessments have been made of the consequences of large airborne releases of radioactive material has not changed much conceptually. The models to describe the atmospheric dispersion of the radioactive material have generally been time-invariant, i.e., the meteorological conditions (thermal stability, wind speed, and precipitation) are invariant during release and the subsequent period of radiation exposure of the population to the airborne material. The frequency distribution of the meteorological conditions are determined by analyzing several years of weather data from the appropriate geographical location. In reality, weather is continuously changing over short time periods (hours) following the release. It is to be expected that the changing meteorological conditions would have important effects on the potential consequences of the release. A time-dependent atmospheric dispersion model was developed and implemented in the Reactor Safety Study. This paper provides a description of the model and the nature of the results generated. Emphasis is given to an explanation of how, and why, these results differ from those estimated with time-invariant models

  14. Derived emergency reference levels for the introduction of countermeasures in the early to intermediate phases of emergencies involving the release of radioactive materials to atmosphere

    International Nuclear Information System (INIS)

    Linsley, G.S.; Crick, M.J.; Simmonds, J.R.; Haywood, S.M.

    1986-03-01

    Derived Emergency Reference Levels (DERLs) are practical quantities intended for use in the aftermath of an accident involving the release of radioactive materials to atmosphere and for use in preparing emergency plans for the protection of the public. The results of environmental measurements may be compared with them as a means of assessing the seriousness of the release and in order to form judgements on the need to institute protective countermeasures. DERLs are the practical expression of Emergency Reference Levels, the radiological criteria for planning the introduction of emergency countermeasures. DERLs have been evaluated for a range of radionuclides which could be released in the event of an accident and for a number of different exposure pathways that are relevant in the initial phase of an accident. These pathways are: inhalation of activity both in the plume and resuspended from the ground; skin irradiation by β-emitting noble gases in the cloud; doses from β-emitters deposited on the skin; and external γ irradiation from ground deposits. (author)

  15. Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 5. Accidental Releases

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, S

    2007-08-15

    Over the course of fifty-three years, LLNL had six acute releases of tritiated hydrogen gas (HT) and one acute release of tritiated water vapor (HTO) that were too large relative to the annual releases to be included as part of the annual releases from normal operations detailed in Parts 3 and 4 of the Tritium Dose Reconstruction (TDR). Sandia National Laboratories/California (SNL/CA) had one such release of HT and one of HTO. Doses to the maximally exposed individual (MEI) for these accidents have been modeled using an equation derived from the time-dependent tritium model, UFOTRI, and parameter values based on expert judgment. All of these acute releases are described in this report. Doses that could not have been exceeded from the large HT releases of 1965 and 1970 were calculated to be 43 {micro}Sv (4.3 mrem) and 120 {micro}Sv (12 mrem) to an adult, respectively. Two published sets of dose predictions for the accidental HT release in 1970 are compared with the dose predictions of this TDR. The highest predicted dose was for an acute release of HTO in 1954. For this release, the dose that could not have been exceeded was estimated to have been 2 mSv (200 mrem), although, because of the high uncertainty about the predictions, the likely dose may have been as low as 360 {micro}Sv (36 mrem) or less. The estimated maximum exposures from the accidental releases were such that no adverse health effects would be expected. Appendix A lists all accidents and large routine puff releases that have occurred at LLNL and SNL/CA between 1953 and 2005. Appendix B describes the processes unique to tritium that must be modeled after an acute release, some of the time-dependent tritium models being used today, and the results of tests of these models.

  16. Modulation of precipitation by conditional symmetric instability release

    OpenAIRE

    Glinton, Michael R.; Gray, Suzanne L.; Chagnon, Jeffrey M.; Morcrette, Cyril J.

    2017-01-01

    Although many theoretical and observational studies have investigated the mechanism of conditional symmetric instability (CSI) release and associated it with mesoscale atmospheric phenomena such as frontal precipitation bands, cloud heads in rapidly developing extratropical cyclones and sting jets, its climatology and contribution to precipitation have not been extensively documented. The aim of this paper is to quantify the contribution of CSI release, yielding slantwise convection, to clima...

  17. Impacts of an Ammonia Leak on the Cabin Atmosphere of the International Space Station

    Science.gov (United States)

    Duchesne, Stephanie M.; Sweterlitsch, Jeffrey J.; Son, Chang H.; Perry Jay L.

    2012-01-01

    Toxic chemical release into the cabin atmosphere is one of the three major emergency scenarios identified on the International Space Station (ISS). The release of anhydrous ammonia, the coolant used in the U.S. On-orbit Segment (USOS) External Active Thermal Control Subsystem (EATCS), into the ISS cabin atmosphere is one of the most serious toxic chemical release cases identified on board ISS. The USOS Thermal Control System (TCS) includes an Internal Thermal Control Subsystem (ITCS) water loop and an EATCS ammonia loop that transfer heat at the interface heat exchanger (IFHX). Failure modes exist that could cause a breach within the IFHX. This breach would result in high pressure ammonia from the EATCS flowing into the lower pressure ITCS water loop. As the pressure builds in the ITCS loop, it is likely that the gas trap, which has the lowest maximum design pressure within the ITCS, would burst and cause ammonia to enter the ISS atmosphere. It is crucial to first characterize the release of ammonia into the ISS atmosphere in order to develop methods to properly mitigate the environmental risk. This paper will document the methods used to characterize an ammonia leak into the ISS cabin atmosphere. A mathematical model of the leak was first developed in order to define the flow of ammonia into the ISS cabin atmosphere based on a series of IFHX rupture cases. Computational Fluid Dynamics (CFD) methods were then used to model the dispersion of the ammonia throughout the ISS cabin and determine localized effects and ventilation effects on the dispersion of ammonia. Lastly, the capabilities of the current on-orbit systems to remove ammonia were reviewed and scrubbing rates of the ISS systems were defined based on the ammonia release models. With this full characterization of the release of ammonia from the USOS TCS, an appropriate mitigation strategy that includes crew and system emergency response procedures, personal protection equipment use, and atmosphere monitoring

  18. Unexpected Impacts of Global warming on Extreme Warm Spells

    Science.gov (United States)

    Sardeshmukh, P. D.; Compo, G. P.; McColl, C.; Penland, C.

    2017-12-01

    It is generally presumed that the likelihood of extreme warm spells around the globe has increased, and will continue to increase, due to global warming. However, we find that this is generally not true in three very different types of global observational datasets and uncoupled atmospheric model simulations of the 1959 to 2012 period with prescribed observed global SSTs, sea ice, and radiative forcing changes. While extreme warm spells indeed became more common in many regions, in many other regions their likelihood remained almost the same or even decreased from the first half to the second half of this period. Such regions of unexpected changes covered nearly 40 percent of the globe in both winter and summer. The basic reason for this was a decrease of temperature variability in such regions that offset or even negated the effect of the mean temperature shift on extreme warm spell probabilities. The possibility of such an impact on extreme value probabilities was highlighted in a recent paper by Sardeshmukh, Compo, and Penland (Journal of Climate 2015). The consistency of the changes in extreme warm spell probabilities among the different observational datasets and model simulations examined suggests that they are robust regional aspects of global warming associated with atmospheric circulation changes. This highlights the need for climate models to represent not just the mean regional temperature signals but also the changes in subseasonal temperature variability associated with global warming. However, current climate models (both CMIP3 and CMIP5) generally underestimate the magnitude of the changes in the atmospheric circulation and associated temperature variability. A likely major cause of this is their continuing underestimation of the magnitude of the spatial variation of tropical SST trends. By generating an overly spatially bland tropical SST warming in response to changes in radiative forcing, the models spuriously mute tropically

  19. Assessment of 99Tc releases to the atmosphere: a plea for applied research

    International Nuclear Information System (INIS)

    Till, J.E.; Hoffman, F.O.; Dunning, D.E. Jr.

    1978-06-01

    Recent experimental data suggest that the concentration factor for uptake of 99 Tc by vegetation from soils may be two to three orders of magnitude higher than the 0.25 value currently being used in radiological assessments. Following a survey of the literature, a concentration factor of 50 was applied to evaluate the dose from a 1.0 Ci/year release to the atmosphere by a hypothetical uranium enrichment facility. Doses to the GI tract and thyroid of an adult living 1600 m from the facility were 18 millirems and 80 millirems, respectively. These doses are delivered entirely through transport of 99 Tc through food chain pathways. This assessment indicates a potential for 99 Tc exposures to exceed recently proposed standards of the U.S. Environmental Protection Agency in 40 CFR 190. The previously assumed concentration factor of 0.25 would have produced corresponding doses of 0.13 millirem to the GI tract and 0.57 millirem to the thyroid. The results of this analysis demonstrate the need for additional research on the environmental behavior and dosimetry of 99 Tc. In particular, data are needed to elucidate the retention of 99 Tc in soils and the uptake of 99 Tc by edible vegetation in field studies of chronic exposure conditions. Data on the uptake and retention of 99 Tc in humans are also necessary to improve the reliability of dose conversion factors for specific organs and various age groups

  20. Model-Data Fusion and Adaptive Sensing for Large Scale Systems: Applications to Atmospheric Release Incidents

    Science.gov (United States)

    Madankan, Reza

    All across the world, toxic material clouds are emitted from sources, such as industrial plants, vehicular traffic, and volcanic eruptions can contain chemical, biological or radiological material. With the growing fear of natural, accidental or deliberate release of toxic agents, there is tremendous interest in precise source characterization and generating accurate hazard maps of toxic material dispersion for appropriate disaster management. In this dissertation, an end-to-end framework has been developed for probabilistic source characterization and forecasting of atmospheric release incidents. The proposed methodology consists of three major components which are combined together to perform the task of source characterization and forecasting. These components include Uncertainty Quantification, Optimal Information Collection, and Data Assimilation. Precise approximation of prior statistics is crucial to ensure performance of the source characterization process. In this work, an efficient quadrature based method has been utilized for quantification of uncertainty in plume dispersion models that are subject to uncertain source parameters. In addition, a fast and accurate approach is utilized for the approximation of probabilistic hazard maps, based on combination of polynomial chaos theory and the method of quadrature points. Besides precise quantification of uncertainty, having useful measurement data is also highly important to warranty accurate source parameter estimation. The performance of source characterization is highly affected by applied sensor orientation for data observation. Hence, a general framework has been developed for the optimal allocation of data observation sensors, to improve performance of the source characterization process. The key goal of this framework is to optimally locate a set of mobile sensors such that measurement of textit{better} data is guaranteed. This is achieved by maximizing the mutual information between model predictions

  1. Coral reefs - sources or sinks of atmospheric CO[sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Ware, J R; Smith, S V; Reakakudla, M L [Hawaii University, Honolulu, HI (USA). Dept. of Oceanography

    1992-09-01

    Because the precipitation of calcium carbonate results in the sequestering of carbon, it frequently has been thought that coral reefs function as sinks of global atmospheric CO[sub 2]. However, the precipitation of calcium carbonate is accompanied by a shift of pH that results in the release of CO[sub 2]. This release of CO[sub 2] is less in buffered sea water than fresh water systems; nevertheless, coral reefs are sources, not sinks, of atmospheric carbon. Using estimated rates of coral reef carbonate production, we compute that coral reefs release 0.02 to 0.08 Gt C as CO[sub 2] annually. This is approximately 0.4% to 1.4% of the current anthropogenic CO[sub 2] production due to fossil fuel combustion.

  2. An investigation into the causes of unexpected intra-operative transoesophageal echocardiography findings.

    Science.gov (United States)

    Skinner, H J; Mahmoud, A; Uddin, A; Mathew, T

    2012-04-01

    There is uncertainty regarding echocardiography before cardiac surgery, especially with regard to timing and disease progression as well as potential errors. We investigated the causes of unexpected intra-operative transoesophageal echocardiography findings by performing a 33-month audit. We found that there were 50/797 (6%) unexpected findings that led to an alteration in surgical strategy in 34 (4%) patients. Of the unexpected findings, 25 (50%) were unrelated to pre-operative pathology. After reviewing pre-operative studies and reports, unexpected findings were found to be due to: reporting errors in 20 patients (44%); limitations in transthoracic compared to transoesophageal echocardiography in 14 patients (30%); disease progression in 10 patients (22%); and inter-observer variability in two patients (4%). We identified six reports out of 797 (0.8%) that contained potentially serious errors. Surgical management changed in 18/20 (90%) patients in whom the unexpected change was due to reporting error, compared to 16/30 (53%) patients whose pre-operative echocardiogram was correctly reported (p = 0.006). Our study suggests that pre-operative echocardiography reporting errors are common and important. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

  3. Release of gaseous tritium during reprocessing

    International Nuclear Information System (INIS)

    Bruecher, H.; Hartmann, K.

    1983-01-01

    About 50% of the tritium put through an LWR reprocessing plant is obtained as tritium-bearing water, HTO. Gaseous tritium, HT has a radiotoxicity which is by 4 orders of magnitude lower than that of HTO. A possibility for the removal of HTO could therefore be its conversion into the gas phase with subsequent emission of the HT into the atmosphere. However, model computations which are, in part, supported by experimental data reveal that the radiation exposure caused by HT release is only by about one order of magnitude below that caused by HTO. This is being attributed to the relatively quick reoxidation of HT by soil bacteria. Two alternatives for producing HT from HTO (electrolysis; voloxidation with subsequent electrolysis) are presented and compared with the reference process of deep-well injection of HTO. The authors come to the conclusion that tritium removal by HT release into the atmosphere cannot be recommended at present under either radiological or economic aspects. (orig.) [de

  4. Atmospheric dispersion and environmental consequences

    International Nuclear Information System (INIS)

    Hedemann Jensen, P.

    1992-11-01

    Methods are described for assessing early radiation doses due to atmospheric releases of radionuclides, i.e. inhalation and external exposure from the plume and from deposited activity. Data to be used in these assessments are presented. The purpose of the present work is to evaluate methods and data that could be used in emergency situations as well as for emergency planning purposes. The most important direct pathways following a release of airborne radionuclides to the atmosphere are the inhalation pathway and the external exposure pathway from ground-deposited activity. For long-lived radionuclides like 134 Cs and 137 Cs the committed effective external dose from deposited acitivity is 1-2 orders of magnitude larger than the committed effective dose from inhalation. Similarly, the committed effective dose from inhalation is 1-2 orders of magnitude larger than the external γ-dose originating directly from the plume. (au) (21 tabs., 2 ills., 37 refs.)

  5. Unexpected Coexisting Myocardial Infarction Detected by Delayed Enhancement MRI

    Directory of Open Access Journals (Sweden)

    Edouard Gerbaud

    2009-01-01

    Full Text Available We report a case of an unexpected coexisting anterior myocardial infarction detected by delayed enhancement MRI in a 41-year-old man following a presentation with a first episode of chest pain during inferior acute myocardial infarction. This second necrotic area was not initially suspected because there were no ECG changes in the anterior leads and the left descending coronary artery did not present any significant stenoses on emergency coronary angiography. Unrecognised myocardial infarction may carry important prognostic implications. CMR is currently the best imaging technique to detect unexpected infarcts.

  6. The accrual anomaly - focus on changes in specific unexpected accruals results in new evidence

    DEFF Research Database (Denmark)

    Schøler, Finn

    are specifically analyzed, namely the unexpected inventory accrual component and the unexpected accounts receivable accrual component, i.e. changes in accruals not motivated by corresponding changes in company activity-level. Additionally and for comparison, the accounting accruals are split into expected...... and unexpected accruals, estimated by the extended Jones model like in both some US-analyses and some international studies of the accrual anomaly phenomenon. It is found that the persistence of earnings is decreasing in the magnitude of the unexpected accrual components of earnings and that the persistence...... of current earnings performance is particularly decreasing in the magnitude of unexpected changes in inventory. The special accrual parts are related to the perceptions of earnings persistence implicit in the market prices, and it is found that the differences in earnings persistence are not rationally...

  7. Unexpected MRI findings in clinically suspected Legg-Calve-Perthes disease

    Energy Technology Data Exchange (ETDEWEB)

    Lobert, Philip F.; Dillman, Jonathan R.; Strouse, Peter J.; Hernandez, Ramiro J. [University of Michigan Health System, Department of Radiology, Section of Pediatric Radiology, C.S. Mott Children' s Hospital/F3503, Ann Arbor, MI (United States)

    2011-03-15

    In the setting of clinically suspected Legg-Calve-Perthes (LCP) disease and negative/equivocal radiographs, contrast-enhanced MRI can be performed to confirm the diagnosis. To determine the frequency of unexpected causes of hip pain as identified by MRI in children with clinically suspected LCP disease and negative/equivocal radiographs. All pediatric contrast-enhanced MRI examinations of the pelvis and hips performed between January 2000 and February 2009 to evaluate for possible LCP disease in the setting of negative/equivocal radiographs were identified. MRI examinations performed to evaluate for secondary avascular necrosis were excluded. Imaging reports were retrospectively reviewed for unexpected clinically important causes of hip pain. Thirty-six pediatric patients underwent contrast-enhanced MRI examinations for clinically suspected LCP disease in the setting of negative/equivocal radiographs. Twenty-two (61%) imaging studies were normal, while four (11%) imaging studies demonstrated findings consistent with LCP disease. Ten (28%) imaging studies revealed unexpected clinically important causes of hip pain, including nonspecific unilateral joint effusion and synovitis (n = 7, juvenile chronic arthritis was eventually diagnosed in 3 patients), sacral fracture (n = 1), apophyseal injury (n = 1), and femoral head subluxation (n = 1). MRI frequently reveals unexpected clinically important causes of hip pain in children with suspected LCP disease and negative/equivocal radiographs. (orig.)

  8. Novel atmospheric pressure plasma device releasing atomic hydrogen: reduction of microbial-contaminants and OH radicals in the air

    International Nuclear Information System (INIS)

    Nojima, Hideo; Park, Rae-Eun; Kwon, Jun-Hyoun; Suh, Inseon; Jeon, Junsang; Ha, Eunju; On, Hyeon-Ki; Kim, Hye-Ryung; Choi, KyoungHui; Lee, Kwang-Hee; Seong, Baik-Lin; Jung, Hoon; Kang, Shin Jung; Namba, Shinichi; Takiyama, Ken

    2007-01-01

    A novel atmospheric pressure plasma device releasing atomic hydrogen has been developed. This device has specific properties such as (1) deactivation of airborne microbial-contaminants, (2) neutralization of indoor OH radicals and (3) being harmless to the human body. It consists of a ceramic plate as a positive ion generation electrode and a needle-shaped electrode as an electron emission electrode. Release of atomic hydrogen from the device has been investigated by the spectroscopic method. Optical emission of atomic hydrogen probably due to recombination of positive ions, H + (H 2 O)n, generated from the ceramic plate electrode and electrons emitted from the needle-shaped electrode have been clearly observed in the He gas (including water vapour) environment. The efficacy of the device to reduce airborne concentrations of influenza virus, bacteria, mould fungi and allergens has been evaluated. 99.6% of airborne influenza virus has been deactivated with the operation of the device compared with the control test in a 1 m 3 chamber after 60 min. The neutralization of the OH radical has been investigated by spectroscopic and biological methods. A remarkable reduction of the OH radical in the air by operation of the device has been observed by laser-induced fluorescence spectroscopy. The cell protection effects of the device against OH radicals in the air have been observed. Furthermore, the side effects have been checked by animal experiments. The harmlessness of the device has been confirmed

  9. The Canadian experimental HT release of June 10, 1987, US measurements

    International Nuclear Information System (INIS)

    Jalbert, R.A.; Murphy, C.E.

    1988-09-01

    In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of elemental tritium (HT) released to the environment. The experiment involved a 30-minute release of 3.54 TBq (95.7 Ci)of HT to the atmosphere at an elevation of one meter. Scientists from six countries participated in the experiment. The air measurements showed HT concentrations downwind of the release in general agreement with classical atmospheric diffusion (Gaussian) up to the maximum distance measured (400 m). The HTO/HT ratios were shown to slowly increase downwind (∼ 4 x 10/sup /minus/5/ at 50 m to almost 10/sup /minus/3/ at 400 m) as conversion of HT took place. After the release, HTO concentrations in the atmosphere remained elevated. Vegetation samples were also taken since the vegetation and associated soil system have been implicated in the oxidation of HT. Freeze-dried water from vegetation samples was found to be low in HTO immediately after the release suggesting a low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 15--30 kBq/L of water at 50 m from the source), and decreasing by the end of the second day. This pattern suggests oxidation in the soil followed by plant uptake through sorption of soil water. This was confirmed by measurements taken by other groups at the experiment site. The HTO in vegetation decreased with distance downwind with the same pattern as the HT measured during the release indicating that the oxidation of HT was linearly related to the HT concentration in the atmosphere during the exposure period. An adequate description of the process can be made through the observed phenomenon of HT deposition into the soil with subsequent rapid oxidation by soil bacteria. 30 refs., 10 figs., 4 tabs

  10. Chlorine release from biomass. Part 6; Kloravgaang fraan biobraenslen. Del 6

    Energy Technology Data Exchange (ETDEWEB)

    Zintl, Frank; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    Chlorine release from model compounds and different biomass fuels has been studied during thermal treatment in an electric oven in inert atmosphere (N{sub 2}) and with addition of 10% O{sub 2}. The amount of chlorine in all investigated materials has been kept to 2% with addition of KCl solution in methanol. The amount of chlorine was analysed before and after treatment in the decided atmosphere and to the temperature chosen. The influence from different functional groups on the chlorine release at low temperatures has been studied in pyrolysis experiments of simple model compounds with different structures. A good correlation between the chlorine release and the functional groups in the model substances was achieved. Results from the experiments shows that the early chlorine release, is most likely to occur in all biofuels, since all biomass fuels contains biological material with significant amounts of functional groups which can interact with fuel chlorine ( inorganic chlorine)

  11. Complexity in an Unexpected Place: Quantities in Selected Acquisition Reports

    Science.gov (United States)

    2017-12-01

    by the Army Acquisition Executive contains the following language . As a recently delegated Acquisition Category IC program, the AH-64E Apache...Complexity in an Unexpected Place: Quantities in Selected Acquisition Reports Gregory A. Davis, Project Leader Margaret L. Giles David M. Tate I...F E N S E A N A L Y S E S IDA Paper P-8490 Complexity in an Unexpected Place: Quantities in Selected Acquisition Reports Gregory A. Davis

  12. Atmospheric dispersion from releases in the vicinity of buildings

    International Nuclear Information System (INIS)

    Walsh, C.; Jones, J.A.

    2002-01-01

    The objective of this study is to advise FSA on the extent to which its current models for calculating air concentration and deposition for continuous releases close to sites with many buildings are adequate, whether there are circumstances for which the explicit modelling of building wake effects is required, and, if so, to recommend an appropriate model for this. The study considered the predictions of simple Gaussian models and the ADMS model. Results from the models are presented and compared, for a range of on-site building configurations and release locations. In addition, the extent to which details of the buildings on the site are required in ADMS is considered. The results indicate that buildings only affect the predicted concentration in a relatively small area around the site (less than 1 km from the site even for tall buildings). For dose calculations beyond 1 km, no allowance is required for modelling building effects. The results suggest that modelling the effects of buildings can be sensitive to a number of parameters and care should be used in interpreting results for locations within the region affected by buildings. However, because ADMS explicitly treats these factors, it is considered a better model for use than those based on a simple Gaussian approach. (author)

  13. 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

  14. 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

  15. Molecular gas species in the lunar atmosphere

    International Nuclear Information System (INIS)

    Hoffman, J.H.; Hodges, R.R. Jr.

    1975-01-01

    There is good evidence for the existence of very small amounts of methane, ammonia and carbon dioxide in the very tenuous lunar atmosphere which consists primarily of the rare gases helium, neon and argon. All of these gases, except 40 Ar, originate from solar wind particles which impinge on the lunar surface and are imbedded in the surface material. Here they may form molecules before being released into the atmosphere, or may be released directly, as is the case for rare gases. Evidence for the existence of the molecular gas species is based on the pre-dawn enhancement of the mass peaks attributable to these compounds in the data from the Apollo 17 Lunar Mass Spectrometer. Methane is the most abundant molecular gas but its concentration is exceedingly low, 1 x 10 3 mol cm -3 , slightly less than 36 Ar, whereas the solar wind flux of carbon is approximately 2000 times that of 36 Ar. Several reasons are advanced for the very low concentration of methane in the lunar atmosphere

  16. Infra-red photon release from cosmic dust entering into the earth's atmosphere

    International Nuclear Information System (INIS)

    Kobayashi, Koichi

    1975-01-01

    Cosmic dust brings considerably high intensity of energy flux to the upper atmosphere of the earth. Most of this energy can be converted to infra-red radiation. It can be concluded that the infra-red background radiation in the sky of its wavelength of less than about 10μ may considerably originate in the cosmic dust which has entered the earth's atmosphere, or that the upper limit to the flux of cosmic dust is about 10 5 tons/earth year. (author)

  17. The Bulgarian Emergency Response System for dose assessment in the early stage of accidental releases to the atmosphere

    International Nuclear Information System (INIS)

    Syrakov, D.; Veleva, B.; Prodanova, M.; Popova, T.; Kolarova, M.

    2009-01-01

    The Bulgarian Emergency Response System (BERS) is being developed in the Bulgarian National Institute of Meteorology and Hydrology since 1994. BERS is based on numerical weather forecast meteorological information and a numerical long-range dispersion model accounting for the transport, dispersion, chemical and radioactive transformations of pollutants. In the present paper, the further development of this system for a mixture of radioactive gaseous and aerosol pollutants is described. The basic module for the BERS, the numerical dispersion model EMAP, is upgraded with a 'dose calculation block'. Two scenarios for hypothetical accidental atmospheric releases from two NPPs, one in Western, and the other in Eastern Europe, are numerically simulated. The effective doses from external irradiation, from air submersion and ground shinning, effective dose from inhalation and absorbed dose by thyroid gland formed by 37 different radionuclides, significant for the early stage of a nuclear accident, are calculated as dose fields for both case studies and discussed

  18. Models for the evaluation of ingestion doses from the consumption of terrestrial foods following an atmospheric radioactive release

    International Nuclear Information System (INIS)

    Nair, S.

    1984-04-01

    Various methods are described which have been incorporated in the FOODWEB module of the CEGB's NECTAR environmental code and are currently being used within CEGB to assess ingestion doses from consumption of terrestrial foods following an atmospheric radioactive release. Four foodchain models which have been developed within CEGB are fully described and results of typical calculations presented. Also given are the results of a validation of the dynamic model against measured 90 Sr and 137 Cs levels in milk in the U.K. resulting from weapons fallout. Methods are also described for calculating individual and population doses from ingestion using the results of the model calculations. The population dose calculations utilise a data base describing the spatial distribution of production of a wide range of agricultural products. The development of such a data base for Great Britain is described, based on the 1972 land use and livestock census, and maps are presented for each agricultural product. (U.K.)

  19. Effects of atmospheric deposition of energy-related pollutants on water quality: a review and assessment

    International Nuclear Information System (INIS)

    Davis, M.J.

    1981-05-01

    The effects on surface-water quality of atmospheric pollutants that are generated during energy production are reviewed and evaluated. Atmospheric inputs from such sources to the aquatic environment may include trace elements, organic compounds, radionuclides, and acids. Combustion is the largest energy-related source of trace-element emissions to the atmosphere. This report reviews the nature of these emissions from coal-fired power plants and discusses their terrestrial and aquatic effects following deposition. Several simple models for lakes and streams are developed and are applied to assess the potential for adverse effects on surface-water quality of trace-element emissions from coal combustion. The probability of acute impacts on the aquatic environment appears to be low; however, more subtle, chronic effects are possible. The character of acid precipitation is reviewed, with emphasis on aquatic effects, and the nature of existing or potential effects on water quality, aquatic biota, and water supply is considered. The response of the aquatic environment to acid precipitation depends on the type of soils and bedrock in a watershed and the chemical characteristics of the water bodies in question. Methods for identifying regions sensitive to acid inputs are reviewed. The observed impact of acid precipitation ranges from no effects to elimination of fish populations. Coal-fired power plants and various stages of the nuclear fuel cycle release radionuclides to the atmosphere. Radioactive releases to the atmosphere from these sources and the possible aquatic effects of such releases are examined. For the nuclear fuel cycle, the major releases are from reactors and reprocessing. Although aquatic effects of atmospheric releases have not been fully quantified, there seems little reason for concern for man or aquatic biota

  20. Space fireworks for upper atmospheric wind measurements by sounding rocket experiments

    Science.gov (United States)

    Yamamoto, M.

    2016-01-01

    Artificial meteor trains generated by chemical releases by using sounding rockets flown in upper atmosphere were successfully observed by multiple sites on ground and from an aircraft. We have started the rocket experiment campaign since 2007 and call it "Space fireworks" as it illuminates resonance scattering light from the released gas under sunlit/moonlit condition. By using this method, we have acquired a new technique to derive upper atmospheric wind profiles in twilight condition as well as in moonlit night and even in daytime. Magnificent artificial meteor train images with the surrounding physics and dynamics in the upper atmosphere where the meteors usually appear will be introduced by using fruitful results by the "Space firework" sounding rocket experiments in this decade.

  1. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) Release 3.0 - Monthly Summary Groups (MSG)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset, the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), is the most widely-used freely available collection of surface marine observations,...

  2. Consequences of tritium release to water pathways from postulated accidents in a DOE production reactor

    International Nuclear Information System (INIS)

    O'Kula, K.R.; Olson, R.L.; Hamby, D.M.

    1991-01-01

    A full-scale PRA of a DOE production reactor has been completed that considers full release of tritium as part of the severe accident source term. Two classes of postulated reactor accidents, a loss-of-moderator pumping accident and a loss-of-coolant accident, are used to bound the expected dose consequence from liquid pathway release. Population doses from the radiological release associated with the two accidents are compared for aqueous discharge and atmospheric release modes. The expectation values of the distribution of possible values for the societal effective dose equivalent to the general public, given a tritium release to the atmosphere, is 2.8 person-Sv/PBq (9.9 x 10 -3 person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 x 10 -2 person-Sv/Pbq (2.4 x 10 -4 person-rem/Ci) for aqueous releases to the surface streams eventually reaching the Savannah River. Negligible doses are calculated for freshwater fish and saltwater invertebrate consumption, irrigation, and recreational use of the river, given that an aqueous release is assumed to occur. Relative to the balance of fission products released in a hypothetical severe accident, the tritium-related dose is small. This study suggests that application of regional models (1610 km radius) will indicate larger dose consequences from short-term tritium release to the atmosphere than from comparable tritium source terms to water pathways. However, the water pathways assessment is clearly site-specific, and the overall aqueous dose will be dependent on downstream receptor populations and uses of the river

  3. Dose calculation for atmospheric releases from a nuclear accident using RAMS/HYPACT

    International Nuclear Information System (INIS)

    Tamura, Junji; Tomita, Kenichi; Homma, Toshimitsu

    2004-01-01

    This paper describes the investigation of uncertainties in the structure of the atmospheric dispersion/deposition model used in the probabilistic accident consequence assessment code, OSCAAR. To investigate these uncertainties, we have introduced the more sophisticated computer codes, RAMS and HYPACT, which were widely used in the research field of atmospheric phenomena. In this work, the capabilities of the HYPACT model were extended for use in accident consequence assessments. The preliminary comparison between the predictions by OSCAAR and those by RAMS/HYPACT were conducted for both individual and collective consequences in terms of probabilistic results. (author)

  4. The choice of individual dose criterion at which to restrict agricultural produce following an unplanned release of radioactive material to atmosphere

    International Nuclear Information System (INIS)

    Dionian, J.; Simmonds, J.R.

    1985-06-01

    In the event of an accidental release of radioactive material to atmosphere, the introduction of emergency countermeasures will be based on the need to limit the risk to individuals. However, it has been suggested that a form of cost-benefit analysis may be used as an input to decisions on the withdrawal of countermeasures, although it is recognised that these decisions may be influenced by factors other than those directly related to radiological protection. In this study, a method based on cost-benefit analysis is illustrated for assessing the optimum level of individual dose at which restrictions on agricultural production may be considered. This requires monetary values to be assigned to both the lost food production and to the health detriment, expressed as the collective effective dose equivalent commitment. It has been assumed in this analysis that food-supply restrictions are both introduced and withdrawn at the same projected level of annual individual dose. The effect on the optimum dose level of the following parameters is examined: the type of produce restricted; the size of the release; the site and direction of the release; the weather conditions; and the cost assigned to unit collective dose. It is shown that the optimum dose criterion, based on the effective dose equivalent received by an individual from a years intake of food, varies over practically the whole range of individual dose considered, i.e., 0.1 to 50 mSv. However, it is concluded that 5 mSv would represent the optimum dose criterion in a substantial number of cases. (author)

  5. Tracking of atmospheric release of pollution using unmanned aerial vehicles

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Hofman, Radek

    2013-01-01

    Roč. 67, č. 1 (2013), s. 425-436 ISSN 1352-2310 R&D Projects: GA MV VG20102013018 Institutional support: RVO:67985556 Keywords : Data assimilation * Atmospheric dispersion model * Sequential Monte Carlo * Sensor positioning Subject RIV: BC - Control Systems Theory Impact factor: 3.062, year: 2013 http://library.utia.cas.cz/separaty/2012/AS/smidl-0385368.pdf

  6. Flavor release measurement by atmospheric pressure chemical ionization ion trap mass spectrometry, construction of interface and mathematical modeling of release profiles

    DEFF Research Database (Denmark)

    Haahr, Anne-Mette; Madsen, Henrik; Smedsgaard, Jørn

    2003-01-01

    and the method can be used to measure breath from the nose. A mathematical model of the data was developed to give a quantitative method for description and characterization of the release of flavor compounds. The release profiles consisted of two sequences, one for a chewing period, and one for a phasing out...... process. The proposed method for modeling provided a reasonable description of the release process. In addition to flavor compounds, this new interface and mathematical application could provide information on chemicals in the human breath which could be interesting, for example, within medical diagnosis....... with that of the flavor detection threshold. An application study on the release of menthone and menthol from chewing gum by a group of six test persons was performed. Flavored chewing gum was used as a model matrix because of the long chewing periods and the simplicity of the system. It is concluded that the interface...

  7. The FLUKA atmospheric neutrino flux calculation

    CERN Document Server

    Battistoni, G.; Montaruli, T.; Sala, P.R.

    2003-01-01

    The 3-dimensional (3-D) calculation of the atmospheric neutrino flux by means of the FLUKA Monte Carlo model is here described in all details, starting from the latest data on primary cosmic ray spectra. The importance of a 3-D calculation and of its consequences have been already debated in a previous paper. Here instead the focus is on the absolute flux. We stress the relevant aspects of the hadronic interaction model of FLUKA in the atmospheric neutrino flux calculation. This model is constructed and maintained so to provide a high degree of accuracy in the description of particle production. The accuracy achieved in the comparison with data from accelerators and cross checked with data on particle production in atmosphere certifies the reliability of shower calculation in atmosphere. The results presented here can be already used for analysis by current experiments on atmospheric neutrinos. However they represent an intermediate step towards a final release, since this calculation does not yet include the...

  8. Correlation between hydrogen release and degradation of limestone concrete exposed to hot liquid sodium in inert atmosphere

    International Nuclear Information System (INIS)

    Parida, F.C.; Das, S.K.; Sharma, A.K.; Ramesh, S.S.; Somayajulu, P.A.; Kannan, S.E.

    2005-01-01

    Full text of publication follows: Concrete is used as a structural material in a Fast Breeder Reactor (FBR) plant for the construction of its foundation, containment, radiation shield and equipment support structures. An accidental leakage of hot sodium on these civil structures can bring about thermo-chemical reactions, with concrete producing hydrogen gas and causing structural degradation. The concrete damage and hydrogen generation take place concurrently due to conduction of heat from sodium into the concrete and migration of steam / moisture in counter current direction towards sodium. In a series of experiments conducted with limestone concrete for two different types of design corresponding to composition and geometry, were exposed to liquid sodium (∼2 kg) at initial temperatures varying from 180 deg. C to 500 deg. C in an inerted test vessel (Capacity = 203 L). Immersion heater was employed to heat the sodium pool on the concrete cavity during the test period in some test runs. On-line continuous measurement of pressure, temperature, hydrogen gas and oxygen gas was carried out. Pre- and post- test nondestructive testing such as colour photography, spatial profiling of ultrasonic pulse velocity and measurement of dimensions were also conducted. Solid samples were collected from sodium debris by manual core drilling machine and from concrete block by hand held electric drilling machine. These samples were subjected to chemical analysis for the determination of free and bound water along with unburnt and burnt sodium. The hydrogen generation parameters such as average and peak release rate as well as release efficiency are derived from measured test variables. These test variables include temperature, pressure and hydrogen concentration in the argon atmosphere contained in the test vessel. The concrete degradation parameters encompass percentage reduction in ultrasonic pulse velocity, depth of physical and chemical dehydration and sodium penetration. These

  9. Nationwide survey of rotavirus-associated encephalopathy and sudden unexpected death in Japan.

    Science.gov (United States)

    Kawamura, Yoshiki; Ohashi, Masahiro; Ihira, Masaru; Hashimoto, Shuji; Taniguchi, Koki; Yoshikawa, Tetsushi

    2014-08-01

    Rotavirus can cause severe complications such as encephalopathy/encephalitis and sudden unexpected death. The incidence of rotavirus-associated encephalopathy/encephalitis or sudden unexpected death remains unknown. To clarify the clinical features of rotavirus-associated encephalitis/encephalopathy and sudden unexpected death, we conducted a nationwide survey in Japan. A two-part questionnaire was designed to determine the number of the cases and the clinical features of severe cases of rotavirus infection, including encephalitis/encephalopathy and sudden unexpected death, between 2009 and 2011. Of the 1365 questionnaires sent to hospitals, 963 (70.5%) were returned and eligible for analysis. We determined 58 cases of rotavirus-associated encephalitis/encephalopathy and 7 cases of sudden unexpected death. These patients were diagnosed with rotavirus infection by immunochromatography. Although 36/58 (62.1%) encephalitis/encephalopathy patients had no sequelae, 15/58 (25.9%) patients had neurological sequelae, and 7/58 (12.1%) patients had fatal outcomes. Pleocytosis was observed in 9/40 (22.5%) patients and cerebrospinal fluid protein levels were elevated in only 4/40 (10%) patients. Elevated lactate dehydrogenase (LDH) (>500 IU/L) or acidemia (pHdeath were 44.0 and 4.9 cases in Japan, respectively. Elevated LDH (>500 IU/L) or acidemia (pH<7.15) were related to a poor prognosis of the encephalitis/encephalopathy. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  10. The variation of health effects based on the scenarios considering release parameters and meteorological data

    International Nuclear Information System (INIS)

    Jeong, Jong Tae; Ha, Jae Joo

    2000-01-01

    The variation of health effects resulting from the severe accidents of the YGN 3 and 4 nuclear power plants was examined based on scenarios considering the release parameters and meteorological data. The release parameters and meteorological data considered in making basic scenarios are release height, heat content, release time, warning time, wind speed, rainfall rate, and atmospheric stability class. The seasonal scenarios were also made in order to estimate the seasonal variation of health effects by considering seasonal characteristics of Korea. According to the results, there are large differences in consequence analysis from scenario to although an equal amount of radioactive materials is released to the atmosphere. Also, there are large differences in health effects from season to season due to distinct seasonal characteristics of Korea. Therefore, it is necessary to consider seasonal characteristics in developing optimum emergency response strategies

  11. Atmospheric impacts of evaporative cooling systems

    International Nuclear Information System (INIS)

    Carson, J.E.

    1976-10-01

    The report summarizes available information on the effects of various power plant cooling systems on the atmosphere. While evaporative cooling systems sharply reduce the biological impacts of thermal discharges in water bodies, they create (at least, for heat-release rates comparable to those of two-unit nuclear generating stations) atmospheric changes. For an isolated site such as required for a nuclear power plant, these changes are rather small and local, and usually environmentally acceptable. However, one cannot say with certainty that these effects will remain small as the number of reactors on a given site increases. There must exist a critical heat load for a specific site which, if exceeded, can create its own weather patterns, and thus create inadvertent weather changes such as rain and snow, severe thunderstorms, and tornadoes. Because proven mathematical models are not available, it is not now possible to forecast precisely the extent and frequency of the atmospheric effects of a particular heat-dissipation system at a particular site. Field research on many aspects of cooling system operation is needed in order to document and quantify the actual atmospheric changes caused by a given cooling system and to provide the data needed to develop and verify mathematical and physical models. The more important topics requiring field study are plume rise, fogging and icing (from certain systems), drift emission and deposition rates, chemical interactions, cloud and precipitation formation and critical heat-release rates

  12. Assessment of impact of a severe accident at nuclear power plant of Angra dos Reis with release of radionuclides to the atmosphere; Avaliacao do impacto de um acidente severo na usina de Angra dos Reis com liberacao de radionuclideos para a atmosfera

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Andre Silva de

    2015-07-01

    This study had as purpose the assess the impact of a severe accident, and also analyze the dispersion of {sup 131}I in the atmosphere, so that, through concentrating and inhaling dose of the plume, were possible to verify if the results are in accordance with the indicated data by the Plan of Emergency of the CNAAA regarding the Impact Zone and Control. This exercise was performed with the aid of an atmospheric model and a dispersion where to atmospheric modeling we used the data coupling WRF / CALMET and of dispersion, CALPUFF. The suggested accident consists of a Station Blackout at Nuclear Power of Angra (Unit 1), where through the total core involvement, will release 100% of the {sup 131}I to the atmosphere. The value of the total activity in the nucleus to this radionuclide is 7.44 x 1017 Bq, that is relative on the sixth day of burning. This activity will be released through the chimney at a rate in Bq/s in the scenario of 12, 24, 48 and 72 hours of release. Applying the model in the proposed scenario, it is verified that the plume has concentrations of the order of 1020 Bq/m³ and dose of about 108 Sv whose value is beyond of the presented by Eletronuclear in your current emergency plan. (author)

  13. Krypton-85 pollution and atmospheric electricity

    International Nuclear Information System (INIS)

    Harrison, R.G.; ApSimon, H.M.

    1994-01-01

    Krypton-86 is a chemically inert radioactive gas present in the atmosphere, concentrations of which have been greatly increased by nuclear reprocessing and weapons testing since 1945. The long half-life (10.7 yr), allows the gas to mix thoroughly in the atmosphere. Ionization caused by krypton-85 increases the electrical conductivity of atmospheric air. Further increases in krypton-85 emissions seem inevitable. The increase in air conductivity due to release of krypton-85 will vary with height, and be larger over the oceans than over the land. Increases in conductivity will produce uncertain effects on atmospheric phenomena, so changes are compared in magnitude with other factors perturbing the conductivity, such as combustion aerosol burdens, volcanic eruptions and nuclear weapons testing. Conductivity changes are expected to have the greatest significance for meteorological phenomena close to the source. (Author)

  14. Modeling the wind-fields of accidental releases with an operational regional forecast model

    International Nuclear Information System (INIS)

    Albritton, J.R.; Lee, R.L.; Sugiyama, G.

    1995-01-01

    The Atmospheric Release Advisory Capability (ARAC) is an operational emergency preparedness and response organization supported primarily by the Departments of Energy and Defense. ARAC can provide real-time assessments of atmospheric releases of radioactive materials at any location in the world. ARAC uses robust three-dimensional atmospheric transport and dispersion models, extensive geophysical and dose-factor databases, meteorological data-acquisition systems, and an experienced staff. Although it was originally conceived and developed as an emergency response and assessment service for nuclear accidents, the ARAC system has been adapted to also simulate non-radiological hazardous releases. For example, in 1991 ARAC responded to three major events: the oil fires in Kuwait, the eruption of Mt. Pinatubo in the Philippines, and the herbicide spill into the upper Sacramento River in California. ARAC's operational simulation system, includes two three-dimensional finite-difference models: a diagnostic wind-field scheme, and a Lagrangian particle-in-cell transport and dispersion scheme. The meteorological component of ARAC's real-time response system employs models using real-time data from all available stations near the accident site to generate a wind-field for input to the transport and dispersion model. Here we report on simulation studies of past and potential release sites to show that even in the absence of local meteorological observational data, readily available gridded analysis and forecast data and a prognostic model, the Navy Operational Regional Atmospheric Prediction System, applied at an appropriate grid resolution can successfully simulate complex local flows

  15. Response to subcommittee on environment and atmosphere

    International Nuclear Information System (INIS)

    MacCracken, M.C.

    1975-10-01

    The potential effects of chronic release of pollutants on climatic changes are discussed with regard to dose-response characteristics, ambiguities in prediction of climatic effects, ambiguities in measuring climatic effects, research approaches, and approaches to standard setting. A table is presented to show potential atmospheric effects of the following pollutants: CO 2 from fossil fuels, fluorocarbons, nitrogen oxides, 85 K from nuclear power plants, sulfur compounds, dusts, heat and water releases from energy generation processes, and oceanic oil slicks

  16. Unexpected complications of bonded mandibular lingual retainers.

    NARCIS (Netherlands)

    Katsaros, C.; Livas, C.; Renkema, A.M.

    2007-01-01

    INTRODUCTION: The flexible spiral wire (FSW) retainer is the most frequently used type of fixed retainer bonded on all 6 anterior teeth. Our aim in this article was to demonstrate unexpected posttreatment changes in the labiolingual position of the mandibular anterior teeth associated with the use

  17. Chernobyl source term, atmospheric dispersion, and dose estimation

    International Nuclear Information System (INIS)

    Gudiksen, P.H.; Harvey, T.F.; Lange, R.

    1988-02-01

    The Chernobyl source term available for long-range transport was estimated by integration of radiological measurements with atmospheric dispersion modeling, and by reactor core radionuclide inventory estimation in conjunction with WASH-1400 release fractions associated with specific chemical groups. These analyses indicated that essentially all of the noble gases, 80% of the radioiodines, 40% of the radiocesium, 10% of the tellurium, and about 1% or less of the more refractory elements were released. Atmospheric dispersion modeling of the radioactive cloud over the Northern Hemisphere revealed that the cloud became segmented during the first day, with the lower section heading toward Scandinavia and the uppper part heading in a southeasterly direction with subsequent transport across Asia to Japan, the North Pacific, and the west coast of North America. The inhalation doses due to direct cloud exposure were estimated to exceed 10 mGy near the Chernobyl area, to range between 0.1 and 0.001 mGy within most of Europe, and to be generally less than 0.00001 mGy within the US. The Chernobyl source term was several orders of magnitude greater than those associated with the Windscale and TMI reactor accidents, while the 137 Cs from the Chernobyl event is about 6% of that released by the US and USSR atmospheric nuclear weapon tests. 9 refs., 3 figs., 6 tabs

  18. Atmospheric Propagation Modeling Indicates Homing Pigeons use Loft-Specific Infrasonic 'Map' Cues

    Science.gov (United States)

    Hagstrum, J. T.; Baker, L. M.; Spritzer, J. M.; McKenna, M. H.

    2011-12-01

    Pigeons (Columba livia) released at distant sites commonly depart in directions significantly off the actual homeward bearing. Such site-dependent deviations, or biases, for birds from a given loft are generally stable over time, but can also change from hour to hour, day to day, and year to year. At some release sites, birds consistently vanish in random directions and have longer flight times and lower return rates. Release sites characterized by frequent disorientation are not uncommon for pigeon lofts in both Europe and the USA. One such site is the Jersey Hill fire tower in upstate New York located ~120 km W of the Cornell loft in Ithaca. Cornell birds released at Jersey Hill between 1968 and 1987 almost always vanished randomly, although birds from other lofts had little difficulty orienting there. The results for one day, however, stand out: on August 13, 1969, Cornell birds released at Jersey Hill vanished consistently to the NE (r = 0.921; n=7) and returned home after normal flight times. Cornell pigeons released the next day again showed 'normal' behavior for the site and departed randomly. If, in fact, the birds are using acoustic cues to navigate, the long-term acoustic 'dead' zone we propose for Jersey Hill, due to prevailing atmospheric conditions, indicates that the cues are coming from a single, relatively restricted area, most likely surrounding the home loft. We have modeled the transmission of infrasonic waves, presumably coupled to the atmosphere from ocean-generated microseisms (0.14 Hz), between the Cornell loft and a number of release sites using HARPA (Hamiltonian Acoustic Ray-tracing Program for the Atmosphere) and rawinsonde data collected near Albany and Buffalo, NY. The HARPA modeling shows that acoustic signals from the Cornell loft reached Jersey Hill only on a few release days with unusual atmospheric conditions, including August 13, and were launched at angles less than ~2° above horizontal, most likely from steep-sided terrain in

  19. Factors affecting calculations of dose resulting from a tritium release into the atmosphere

    International Nuclear Information System (INIS)

    Otaduy, P.; Easterly, C.E.; Booth, R.S.; Jacobs, D.G.

    1976-01-01

    Tritium releases in the form of HT represent a lower hazard to man than releases as HTO. However, during movement in the environment, HT is converted into HTO. The effects of the conversion rate on calcultions of dose are described, and a general method is presented for determining the dose from tritium for various conversion rates and relative HTO/HT risk factors

  20. Atmospheric release advisory capability pilot project at two nuclear power plants and associated state offices of emergency preparedness. Final report

    International Nuclear Information System (INIS)

    Rosen, L.C.

    1983-01-01

    A project to demonstrate the feasibility of utilizing Atmospheric Release Advisory Capability (ARAC) limited service with commercial nuclear power plants and their associated state offices of emergency preparedness is discussed. Preliminary planning, installation and testing of the ARAC site facilities at Indian Point Nucler Power Station, New York State; at New York State Office of Emergency Preparedness, Albany, New York; at Rancho Seco Nuclear Generating Station, California; and at the State of California Office of Emergency Services, Sacramento, California, are summarized. ARAC participation in the Robert E. Ginna nuclear generating plant accident in New York on January 25, 1982, is discussed. The ARAC system is evaluated with emphasis on communications, the suite of models contained within the ARAC system, and the staff. The implications of this project in designing the next-generation ARAC system to service federal and state needs are assessed

  1. Estimation of atmospheric fluoride by limed filter papers

    International Nuclear Information System (INIS)

    Smith, D.R.

    1988-09-01

    The limed filter paper method of static sampling of atmospheric fluoride is reviewed in this report. Use of the technique, in conjunction with precise measurement of the absorbed fluoride and calibration with dynamic air sampling techniques, to estimate atmospheric fluoride levels, is considered to give only qualitative data (± 50%). The limed filter paper method is site specific due to variations in meteorological conditions. Its main value is to indicate seasonal and annual trends in fluoride exposure of vegetation. Subject to these considerations, the lower and upper limits of atmospheric fluoride exposure and the applicability to atmospheric fluoride estimation under routine or emergency fluoride release conditions are discussed, with special emphasis on the limiting factors

  2. Savannah River release: test of the new ARAC capability

    International Nuclear Information System (INIS)

    Dickerson, M.H.

    1977-01-01

    Working jointly from opposite sides of the nation Lawrence Livermore Laboratory (LLL) and the Savannah River Laboratory (SRL) quickly assessed the consequences of an early-morning tritium release in May 1974 from the Savannah River Plant, in South Carolina. Measurements confirmed the accuracy of the LLL predictions. Due to the small quantity involved and to the release location (well within the plant confines), the release was not dangerous to the public. The emergency provided a dramatic test of procedures and capabilities of the new Atmospheric Release Advisory Capability (ARAC) center at Livermore, which was not yet operational, demonstrating the capacity for quick response, and the feasibility of real-time data acquisition and transmittal across the continent

  3. Aspects of dopamine and acetylcholine release induced by glutamate receptors

    International Nuclear Information System (INIS)

    Paes, Paulo Cesar de Arruda

    2002-01-01

    The basal ganglia play an important role in the motor control of rats and humans. This control involves different neurotransmitters and the mutual control of these key elements has been subject to several studies. In this work we determined the role of glutamate on the release of radioactively labelled dopamine and acetylcholine from chopped striatal tissue in vitro. The values of Effective Concentration 50% for glutamate, NMDA, kainic, quisqualic acids and AMPA on the release of dopamine and acetylcholine were obtained. The inhibitory effects of magnesium, tetrodotoxin, MK-801, AP5 and MCPG, as well as the effects of glycin were evaluated. The results suggested that dopamine is influenced by the NMDA type glutamate receptor while acetylcholine seems to be influenced by NMDA, kainate and AMPA receptors. Tetrodotoxin experiments suggested that kainate receptors are both present in cholinergic terminals and cell bodies while AMPA and NMDA receptors are preferentially distributed in cell bodies. Magnesium effectively blocked the NMDA stimulation and unexpectedly also AMPA- and quisqualate-induced acetylcholine release. The latter could not be blocked by MCPG ruling out the participation of methabotropic receptors. MK-801 also blocked NMDA-receptors. Results point out the importance of the glutamic acid control of dopamine and acetylcholine release in striatal tissue. (author)

  4. The radiological consequences of notional accidental releases of radioactivity from fast breeder reactors: the influence of the meteorological conditions

    International Nuclear Information System (INIS)

    Hemming, C.R.; Hallam, J.; Kelly, G.N.

    1980-04-01

    The radiological consequences of a wide range of notional accidental releases from a 1300 MW(e) LMFBR (liquid Metal-cooled Fast Breeder Reactor) were assessed in a previous study by the National Radiological Protection Board. In the present study the sensitivity of the predicted consequences to the meteorological conditions was investigated. The influence of the wind direction, and hence the distribution of the exposed population, and of atmospheric stability at the time of the release are considered separately. Conclusions are reached on the precision required in specifying atmospheric stability conditions to estimate reliably the distribution of possible consequences following a given release of activity. The probability distributions of consequences for selected releases from two locations are evaluated taking account of the frequency distribution of wind direction and atmospheric stability at each location. The variation is large and demonstrates the importance of taking account of the whole range of meteorological conditions when assessing the risk presented by an accidental release of activity. (author)

  5. Upper atmospheric planetary-wave and gravity-wave observations

    Science.gov (United States)

    Justus, C. G.; Woodrum, A.

    1973-01-01

    Previously collected data on atmospheric pressure, density, temperature and winds between 25 and 200 km from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others were analyzed by a daily-difference method, and results on the magnitude of atmospheric perturbations interpreted as gravity waves and planetary waves are presented. Traveling planetary-wave contributions in the 25-85 km range were found to have significant height and latitudinal variation. It was found that observed gravity-wave density perturbations and wind are related to one another in the manner predicted by gravity-wave theory. It was determined that, on the average, gravity-wave energy deposition or reflection occurs at all altitudes except the 55-75 km region of the mesosphere.

  6. Using the model release ARTM associated with resources for simulation geoprocessing radiological environmental impact of atmospheric emissions from a research reactor

    International Nuclear Information System (INIS)

    Alves, Simone Fonseca

    2013-01-01

    The knowledge of the dispersion of radionuclides emissions into the atmosphere arising from a nuclear reactor, in normal operation, is an important step in the process of the nuclear and environmental assessment study. These processes require an assessment study of the radiological environmental impact. However, to estimate this impact a simulation of the transport mechanisms and deposition of pollutants released into the atmosphere is required. The present study aimed at the application of the dispersion model ARTM (Atmospheric Radionuclide Transport Model), together with the powerful tools of the GIS (Geographic Information System) for the environmental impact assessment of a radiological nuclear reactor under typically routine and conditions. Therefore some important information from the national project for a research reactor known as Brazilian Multipurpose Reactor (RMB) was considered. The information of the atmospheric emissions of the reactor, needed for the simulation of this project, was based on data of the Open Pool Australian Light Water (OPAL).Other important data that had to be collected and analyzed were the source term, the topography, the meteorology and the environmental data. The radionuclides analyzed as pollutants were 41 Ar; 140 Ba; 51 Cr; 137 Cs; 131 I; 133 I; 85m Kr; 87 Kr; 88 Kr; 140 La; 133 Xe; 135 Xe; 3 H; 90 Sr. The model was run for two chronological scenarios according to their meteorological data for the years 2009 and 2010, respectively. The adoption of GIS techniques was relevant in planning, data preprocessing and in the post-processing of results as well. After pre-processing, the input data were processed by the ARTM dispersion model. Maps, charts, and tables were then produced and evaluated. According to the simulated and evaluated scenarios it could be concluded that exposure pathways that mostly contributed to the dose for individual public were 41 Ar, for immersion in the plume, and 133 I, for inhalation. Nevertheless, even

  7. Analyses of postulated accidental releases of UF6 inside process buildings

    International Nuclear Information System (INIS)

    Oliveira Neto, Jose Messias de; Nunes, Beatriz Guimaraes; Dias, Cristiane

    2009-01-01

    Uranium Hexafluoride is a material used in the various processes which comprise the front end of the nuclear fuel cycle (conversion, enrichment and fuel fabrication). Confinement of UF 6 is a very important safety requirement since this material is highly reactive and presents safety hazards to humans. The present paper discusses the safety relevant aspects of accidental releases of UF 6 inside process confinement buildings. Postulated accidental scenarios are analyzed and their consequences evaluated. Implant releases rates are estimated using computer code predictions. A time dependent homogeneous compartment model is used to predict concentrations of UF 6 , hydrogen fluoride and uranyl fluoride inside a confinement building, as well as to evaluate source terms released to the atmosphere. These source terms can be used as input to atmospheric dispersion models to evaluate consequences to the environment. The results can also be used to define adequate protective measures for emergency situations. (author)

  8. Evaluation of radiological releases from the Tomsk-7 accident

    Energy Technology Data Exchange (ETDEWEB)

    Lussie, W.G.

    1995-10-01

    On April 6, 1993, there was an uncontrolled release of radioactive material from the fuel reprocessing plant at the Siberian Chemical Combine in Tomsk. The release resulted from the rupture of an over-pressurized feed adjustment tank and subsequent explosion that destroyed the walls and roof of the operating gallery. Radioactive material was released through a 150 meter stack, as well as through the destroyed walls and roof. Relatively stable atmospheric conditions prevailed and a light snow was falling. The radiation release was not excessive, but the spread of radioactive material was compounded by the explosion. Radiation was detected about 26 km from the source. This paper summarizes the information available in the US regarding the release and, using reasonable assumptions, compares the calculated ground activity and radiation levels with the reported measured values.

  9. Evaluation of radiological releases from the Tomsk-7 accident

    International Nuclear Information System (INIS)

    Lussie, W.G.

    1995-01-01

    On April 6, 1993, there was an uncontrolled release of radioactive material from the fuel reprocessing plant at the Siberian Chemical Combine in Tomsk. The release resulted from the rupture of an over-pressurized feed adjustment tank and subsequent explosion that destroyed the walls and roof of the operating gallery. Radioactive material was released through a 150 meter stack, as well as through the destroyed walls and roof. Relatively stable atmospheric conditions prevailed and a light snow was falling. The radiation release was not excessive, but the spread of radioactive material was compounded by the explosion. Radiation was detected about 26 km from the source. This paper summarizes the information available in the US regarding the release and, using reasonable assumptions, compares the calculated ground activity and radiation levels with the reported measured values

  10. Method of instantaneous approximation of the atmospheric dispersion

    International Nuclear Information System (INIS)

    Doury, A.

    1983-12-01

    A basic primary modelling, very simple and compatible with all the existing models. The problem, the simplifying hypothesis being given, amounts to calculating a concentration chi determined by a fixed quantity Q released instantaneously in a quasi nil volume and uniformly distributed after the time t after the emission in a rectangular parallelepipedic volume. An atmospheric dilution coefficient and an atmospheric transfer coefficient are defined. From these elements, such defined, it is possible to establish of ''short term'' and ''long term'' transfer coefficients and also transfer coefficients ''in the atmosphere'' and to the ''ground''. They are presented in a tabular form [fr

  11. Radioactive iodine releases from nuclear power plant, (2)

    International Nuclear Information System (INIS)

    Naritomi, Mitsuo

    1974-01-01

    Internal radiation dose through the respiratory intake of fission products is predominantly due to radioactive iodine not only at the time of reactor accidents but also in normal operation of nuclear facilities. Technological studies in this field have thus been quite active to this day. With the rapid advance of nuclear power generation in recent years, the efforts to reduce environmental release of radioactive iodine and to enhance environmental safety are all the more emphasized. Experiences in the Japan Atomic Energy Research Institute during past about six years are described concerning the radioactive iodine release to the atmosphere in 131 I production and the measures taken to reduce the release. Then, problems are expounded regarding the radioactive iodine release at the time of reactor accidents and in spent fuel reprocessing. (Mori, K.)

  12. 77 FR 42947 - Unexpected Urgent Refugee and Migration Needs

    Science.gov (United States)

    2012-07-20

    ... unexpected and urgent refugee and migration needs, including by contributions to international, governmental, and nongovernmental organizations and payment of administrative expenses of the Bureau of Population...

  13. Unexpected temporal evolution of atomic spectral lines of aluminum in a laser induced breakdown spectroscopy experiment

    International Nuclear Information System (INIS)

    Saad, Rawad; L'Hermite, Daniel; Bousquet, Bruno

    2014-01-01

    The temporal evolution of the laser induced breakdown (LIBS) signal of a pure aluminum sample was studied under nitrogen and air atmospheres. In addition to the usual decrease of signal due to plasma cooling, unexpected temporal evolutions were observed for a spectral lines of aluminum, which revealed the existence of collisional energy transfer effects. Furthermore, molecular bands of AlN and AlO were observed in the LIBS spectra, indicating recombination of aluminum with the ambient gas. Within the experimental conditions reported in this study, both collisional energy transfer and recombination processes occurred around 1.5 μs after the laser shot. This highlights the possible influence of collisional and chemical effects inside the plasma that can play a role on LIBS signals. - Highlights: • Persistence of two Al I lines related to the 61,844 cm −1 energy level only under nitrogen atmosphere. • Collisional energy transfer effect exists between aluminum and nitrogen. • Observation of molecular band of AlN (under nitrogen) and AlO (under air) after a delay time of 1.5 µs. • 20% of oxygen in air is sufficient to annihilate both the collisional energy transfer effect and the AlN molecular formation

  14. Cosmogenic radionuclide carriers in the atmosphere

    International Nuclear Information System (INIS)

    Lujaniene, G.; Lujanas, V.

    1998-01-01

    The investigation of radionuclides ( 7 Be 32,33 P and 35 S) and stable sulfur and phosphorus forms was based on the Tessier sequential extraction method. The properties of radionuclide carriers can be transformed in the atmosphere in a very short time (days, hours), in contrast to soil and the hydrosphere. Oxidation processes proceeding in the atmosphere induce changes in the aerosol carrier properties. The aerosol can be characterized by low pH and high Eh values corresponding to high 7Be solubility. The unexpectedly high negative Eh values obtained in dry summer period indicate that the 7 Be 32,33 P aerosol is bound to insoluble carriers. 137 Cs solubility does not depend on changes in pH. This can be explained by the fact that in contrast to 7 Be, 137 Cs is associated with the exchangeable fraction. Cs ions can be replaced not only by H + but also by NH 4 + and other ions. 7 Be aerosols collected at the seaside of the Baltic sea (Preila) were found to be more soluble than those in Vilnius, their solubility was up to 50-90 % and clear dependence between 7 Be solubility, pH and Eh was not observed. It can be attributed to differences in the atmospheric aerosol composition (e.g. soluble chlorides) in Vilnius and Preila. A great variety of 7 Be carriers properties as well as their dependence on the season and the existence of admixtures in the atmosphere require great caution in applying this isotope in tracer investigations. Soluble carriers are removed faster from the atmosphere by precipitation. The significance of this fact is confirmed by the ratio of 7 Be/ 32 P in the air and precipitation. Both soluble and insoluble aerosols can be formed depending on the environmental conditions

  15. Release and attenuation of fluorocarbons in landfills

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2003-01-01

    Several halocarbons with very high global warming and ozone depleting potentials have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam...... blown with CFC-11, HCFC-141b, HFC- 134a, and HFC-245fa revealed that most of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period is highly dependent on how fine the foam is shredded....... The residual blowing agent remaining after the six-week period may be very slowly released if the integrity of the foam particles with respect to diffusional properties is kept after disposal of the foam waste in landfills. Laboratory experiments simulating attenuation processes in the landfilled waste...

  16. Lithosphere-atmosphere-ionosphere coupling as governing mechanism for preseismic short-term events in atmosphere and ionosphere

    Directory of Open Access Journals (Sweden)

    O. Molchanov

    2004-01-01

    Full Text Available We present a general concept of mechanisms of preseismic phenomena in the atmosphere and ionosphere. After short review of observational results we conclude: 1. Upward migration of fluid substrate matter (bubble can lead to ousting of the hot water/gas near the ground surface and cause an earthquake (EQ itself in the strength-weakened area; 2. Thus, time and place of the bubble appearance could be random values, but EQ, geochemistry anomaly and foreshocks (seismic, SA and ULF electromagnetic ones are casually connected; 3. Atmospheric perturbation of temperature and density could follow preseismic hot water/gas release resulting in generation of atmospheric gravity waves (AGW with periods in a range of 6–60min; 4. Seismo-induced AGW could lead to modification of the ionospheric turbulence and to the change of over-horizon radio-wave propagation in the atmosphere, perturbation of LF waves in the lower ionosphere and ULF emission depression at the ground.

  17. Atmospheric anomalies in summer 1908: Water in the atmosphere

    Science.gov (United States)

    Gladysheva, O. G.

    2011-10-01

    A gigantic noctilucent cloud field was formed and different solar halos were observed after the Tunguska catastrophe. To explain these anomalous phenomena, it is necessary to assume that a large quantity of water was carried into the atmosphere, which indicates that the Tunguska cosmic body was of a comet origin. According to rough estimates, the quantity of water that is released into the atmosphere as a result of a cosmic body's destruction is more than 1010 kg. The observation of a flying object in an area with a radius of ≥700 km makes it possible to state that the Tunguska cosmic body looked like a luminous coma with a diameter not smaller than ≥10 km and became visible at heights of >500 km. The assumption that the Tunguska cosmic body started disintegrating at a height of ˜1000 km explains the formation of an area where its mater diffused and formed a luminous area above Europe.

  18. Atmospheric tracer tests and assessment of a potential accident at the National Medical Cyclotron, Camperdown, NSW, Australia

    International Nuclear Information System (INIS)

    Clark, G.H.; Bartsch, F.J.K.; Stone, D.J.M.

    1994-08-01

    In order to assess the impact of a potential atmospheric release of radionuclides from the National Medical Cyclotron facility, in Camperdown, an atmospheric tracer release, sampling and analysis system using SF 6 was developed. During eight experiments conducted in a variety of meteorological conditions, ten samplers were located in the vicinity of the Cyclotron building and other nearby buildings on the rapid downward movement of the tracer gas plume. The atmospheric dilution factors which lead to the highest observed air concentrations were then applied to the releases of I 123 and Xe 123 from a potential accident scenario in order to assess the impact on nearby receptors. Even given the conservative assumptions about the release of I 123 , the estimated radiation doses were at least an order of magnitude below the international standards for doses to member of the public. 27 refs., 8 tabs., 5 figs

  19. Atmospheric tracer tests and assessment of a potential accident at the National Medical Cyclotron, Camperdown, NSW, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Bartsch, F J.K.; Stone, D J.M.

    1994-08-01

    In order to assess the impact of a potential atmospheric release of radionuclides from the National Medical Cyclotron facility, in Camperdown, an atmospheric tracer release, sampling and analysis system using SF{sub 6} was developed. During eight experiments conducted in a variety of meteorological conditions, ten samplers were located in the vicinity of the Cyclotron building and other nearby buildings on the rapid downward movement of the tracer gas plume. The atmospheric dilution factors which lead to the highest observed air concentrations were then applied to the releases of I{sup 123} and Xe{sup 123} from a potential accident scenario in order to assess the impact on nearby receptors. Even given the conservative assumptions about the release of I{sup 123}, the estimated radiation doses were at least an order of magnitude below the international standards for doses to member of the public. 27 refs., 8 tabs., 5 figs.

  20. Are biogenic emissions a significant source of summertime atmospheric toluene in the rural Northeastern United States?

    OpenAIRE

    M. L. White; R. S. Russo; Y. Zhou; J. L. Ambrose; K. Haase; E. K. Frinak; R. K. Varner; O. W. Wingenter; H. Mao; R. Talbot; B. C. Sive

    2009-01-01

    Summertime atmospheric toluene enhancements at Thompson Farm in the rural northeastern United States were unexpected and resulted in a toluene/benzene seasonal pattern that was distinctly different from that of other anthropogenic volatile organic compounds. Consequently, three hydrocarbon sources were investigated for potential contributions to the enhancements during 2004–2006. These included: (1) increased warm season fuel evaporation coupled with changes in reformulated gasoline (RFG) con...

  1. Simulation of atmospheric dispersion of radionuclides using an Eulerian-Lagrangian modelling system.

    Science.gov (United States)

    Basit, Abdul; Espinosa, Francisco; Avila, Ruben; Raza, S; Irfan, N

    2008-12-01

    In this paper we present an atmospheric dispersion scenario for a proposed nuclear power plant in Pakistan involving the hypothetical accidental release of radionuclides. For this, a concept involving a Lagrangian stochastic particle model (LSPM) coupled with an Eulerian regional atmospheric modelling system (RAMS) is used. The atmospheric turbulent dispersion of radionuclides (represented by non-buoyant particles/neutral traces) in the LSPM is modelled by applying non-homogeneous turbulence conditions. The mean wind velocities governed by the topography of the region and the surface fluxes of momentum and heat are calculated by the RAMS code. A moving least squares (MLS) technique is introduced to calculate the concentration of radionuclides at ground level. The numerically calculated vertical profiles of wind velocity and temperature are compared with observed data. The results obtained demonstrate that in regions of complex terrain it is not sufficient to model the atmospheric dispersion of particles using a straight-line Gaussian plume model, and that by utilising a Lagrangian stochastic particle model and regional atmospheric modelling system a much more realistic estimation of the dispersion in such a hypothetical scenario was ascertained. The particle dispersion results for a 12 h ground release show that a triangular area of about 400 km(2) situated in the north-west quadrant of release is under radiological threat. The particle distribution shows that the use of a Gaussian plume model (GPM) in such situations will yield quite misleading results.

  2. Atmospheric corrosion: statistical validation of models

    International Nuclear Information System (INIS)

    Diaz, V.; Martinez-Luaces, V.; Guineo-Cobs, G.

    2003-01-01

    In this paper we discuss two different methods for validation of regression models, applied to corrosion data. One of them is based on the correlation coefficient and the other one is the statistical test of lack of fit. Both methods are used here to analyse fitting of bi logarithmic model in order to predict corrosion for very low carbon steel substrates in rural and urban-industrial atmospheres in Uruguay. Results for parameters A and n of the bi logarithmic model are reported here. For this purpose, all repeated values were used instead of using average values as usual. Modelling is carried out using experimental data corresponding to steel substrates under the same initial meteorological conditions ( in fact, they are put in the rack at the same time). Results of correlation coefficient are compared with the lack of it tested at two different signification levels (α=0.01 and α=0.05). Unexpected differences between them are explained and finally, it is possible to conclude, at least in the studied atmospheres, that the bi logarithmic model does not fit properly the experimental data. (Author) 18 refs

  3. Dispersion and transport of atmospheric pollutants

    International Nuclear Information System (INIS)

    Cieslik, S.

    1991-01-01

    This paper presents the physical mechanisms that govern the dispersion and transport of air pollutant; the influence of the state of the 'carrying fluid', i.e. the role of meteorology; and finally, outlines the different techniques of assessing the process. Aspects of physical mechanisms and meteorology covered include: fate of an air pollutant; turbulence and dispersion; transport; wind speed and direction; atmospheric stability; and the role of atmospheric water. Assessment techniques covered are: concentrations measurements; modelling meteorological observations; and tracer releases. It is concluded that the only way to reduce air pollution is to pollute less. 10 refs., 12 figs., 2 tabs

  4. Frequency, severity and causes of unexpected allergic reactions to food: a systematic literature review.

    Science.gov (United States)

    Versluis, A; Knulst, A C; Kruizinga, A G; Michelsen, A; Houben, G F; Baumert, J L; van Os-Medendorp, H

    2015-02-01

    Food allergic patients have to deal with an avoidance diet. Confusing labelling terms or precautionary labels can result in misinterpretation and risk-taking behaviour. Even those patients that strictly adhere to their diet experience (sometimes severe) unexpected allergic reactions to food. The frequency, severity and causes of such reactions are unknown. The objective of this review was to describe the frequency, severity and causes of unexpected allergic reactions to food in food allergic patients aged > 12 years, in order to develop improved strategies to deal with their allergy. A systematic review was carried out by two researchers, in six electronic databases (CINAHL, Cochrane, EMBASE, Medline, Psychinfo and Scopus). The search was performed with keywords relating to the frequency, severity and causes of unexpected allergic reactions to food. This resulted in 24 studies which met the inclusion criteria; 18 observational and six qualitative studies. This review shows that knowledge about the frequency of unexpected reactions is limited. Peanut, nuts, egg, fruit/vegetables and milk are the main causal foods. Severe reactions and even fatalities occur. Most reactions take place at home, but a significant number also take place when eating at friends' houses or in restaurants. Labelling issues, but also attitude and risky behaviour of patients can attribute to unexpected reactions. We conclude that prospective studies are needed to get more insight in the frequency, severity, quantity of unintended allergen ingested and causes of unexpected allergic reactions to food, to be able to optimize strategies to support patients in dealing with their food allergy. Although the exact frequency is not known, unexpected reactions to food occur in a significant number of patients and can be severe. For clinical practice, this means that patient education and dietary instructions are necessary. © 2014 John Wiley & Sons Ltd.

  5. Limitation of releases and filtration by sand

    International Nuclear Information System (INIS)

    Schektman, N.

    1986-01-01

    In the highly hypothetic case of a severe reactor accident, it may lead to an increase of pressure within the containment and up to a value above the calculated pressure. A procedure is necessary in this case to maintain the integrity of the containment to prevent a release of radioactive products to the environment, while controlling in the best way releases. So, EDF and the CEA have developed a device of decompression-filtration of the containment atmosphere, using a free penetration of the containment and a sand box; the device and its operation constitute the U5 procedure [fr

  6. Low-technology monitoring of atmospheric metal pollution in central Scotland

    Energy Technology Data Exchange (ETDEWEB)

    Yule, F A; Lloyd, O L

    1984-01-01

    In epidemiological studies covering relationships of disease patterns and patterns of atmospheric pollution, conventional filtering equipment is normally used for monitoring the pollution. For various reasons, however, this type of approach often results in levels of pollution being obtained for only a few sites within an extensive fieldwork area. Hence, alternative monitoring techniques, which allow a high density of sampling sites in an area, have been of interest to an increasing number of investigators. The monitors used, known as low-technology monitors, fall into two main categories; indigenous; and transplants. In the authors surveys of atmospheric metal pollutants in industrial communities in Scotland, the indigenous sample materials have included: Hypnum cupressiforme, Lecanora conizaeoides, Agropyron repens and surface soils. In their transplant surveys a variety of different low-technology samplers have been deployed, the most frequently used being: spherical and flat moss bags, Hypogymnia physodes, Tak (synthetic fabric), and total deposition collectors. The data obtained from the various surveys have been plotted on a variety of types of computer map to minimize any systematic bias resulting from the use of a single technique. The pollution patterns found in one particular town were partly unexpected, in view of the dominant wind direction in the locality concerned. Hence it was decided to carry out a wind tunnel experiment to investigate the situation further. The wind tunnel experiment produced results which were consistent with the patterns of pollution derived from the metal surveys, and revealed that the meteorological dispersal of the pollution was unexpectedly influenced by local topography.

  7. Unexpected secoiridoid glucosides from Manulea corymbosa.

    Science.gov (United States)

    Gousiadou, Chrysoula; Kokubun, Tetsuo; Gotfredsen, Charlotte H; Jensen, Søren R

    2014-03-28

    From an extract of Manulea corymbosa were isolated four known secoiridoid glucosides (1-4), 10 new monoterpenoid esters of secologanol, namely, manuleosides A-I (5-11, 13, and 14) and dimethyl rhodanthoside A (12), and four new phenylpropanoid esters of carbocyclic iridoid glucosides, manucorymbosides I-IV (15-18). Also, the caffeoyl phenylethanoid glycoside verbascoside was isolated. The presence of secoiridoids apparently derived from loganic acid in the family Scrophulariaceae is unprecedented and greatly unexpected.

  8. Short communication: Unexpected findings on the physicochemical characterization of the silver nanoparticle surface

    Science.gov (United States)

    Loran, S.; Yelon, A.; Sacher, E.

    2018-01-01

    The bactericidal properties of silver nanoparticles (Ag NPs) have been variously attributed to the action of the NP surface and/or the Ag ions released therefrom. However, the published literature does not appear to contain any information on the physicochemical characterization of the NP surface. Herein, we report on the surprisingly reactive surface of the Ag NP, which has an almost total lack of free Ag on atmospheric exposure. Rather, an abundance of surface hydrocarbons, hydrides and oxides, as well as amines and oxidized N, argues for a reinterpretation of their bactericidal action.

  9. Noble Gas Surface Flux Simulations And Atmospheric Transport

    Energy Technology Data Exchange (ETDEWEB)

    Carrigan, Charles R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sun, Yunwei [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-30

    Signatures from underground nuclear explosions or UNEs are strongly influenced by the containment regime surrounding them. The degree of gas leakage from the detonation cavity to the surface obviously affects the magnitude of surface fluxes of radioxenon that might be detected during the course of a Comprehensive Test Ban Treaty On-Site Inspection. In turn, the magnitude of surface fluxes will influence the downwind detectability of the radioxenon atmospheric signature from the event. Less obvious is the influence that leakage rates have on the evolution of radioxenon isotopes in the cavity or the downwind radioisotopic measurements that might be made. The objective of this letter report is to summarize our attempt to better understand how containment conditions affect both the detection and interpretation of radioxenon signatures obtained from sampling at the ground surface near an event as well as at greater distances in the atmosphere. In the discussion that follows, we make no attempt to consider other sources of radioactive noble gases such as natural backgrounds or atmospheric contamination and, for simplicity, only focus on detonation-produced radioxenon gases. Summarizing our simulations, they show that the decay of radioxenon isotopes (e.g., Xe-133, Xe-131m, Xe-133m and Xe-135) and their migration to the surface following a UNE means that the possibility of detecting these gases exists within a window of opportunity. In some cases, seeps or venting of detonation gases may allow significant quantities to reach the surface and be released into the atmosphere immediately following a UNE. In other release scenarios – the ones we consider here – hours to days may be required for gases to reach the surface at detectable levels. These release models are most likely more characteristic of “fully contained” events that lack prompt venting, but which still leak gas slowly across the surface for periods of months.

  10. Thermal stability of inorganic and organic compounds in atmospheric particulate matter

    Science.gov (United States)

    Perrino, Cinzia; Marconi, Elisabetta; Tofful, Luca; Farao, Carmela; Materazzi, Stefano; Canepari, Silvia

    2012-07-01

    The thermal behaviour of atmospheric particulate matter (PM) has been investigated by using different analytical approaches to explore the added value offered by these technique in environmental studies. The thermogravimetric analysis (TGA), carried out on both certified material and real PM samples, has shown that several mass losses can be detected starting from 80 °C up to above 500 °C, when pyrolysis occur. Thermo-optical analysis of PM and ion chromatographic analysis of the residual have shown that the mass losses in the temperature range 80-180 °C are not justified by the release of either organic or inorganic compounds; it can be thus attributed to the release of weakly and strongly bound water. Release of water has also been evidenced in the temperature range 225-275 °C. The release of ammonium chloride and nitrate has been detected only above 80 °C. This indicates that the release of nitric acid, hydrochloric acid and ammonia, which is observed downstream of the filters during the sampling of atmospheric PM at ambient temperature, cannot be reproduced off-line, after the end of the sampling. We successfully explored one of the possible explanations, that is the desorption of HNO3, HCl and NH3 adsorbed on collected particles. NH4NO3 and NH4Cl, which can be thermally released by the filter, exhibit a different thermal behaviour from NaNO3 and NaCl, which are thermally stable up to 370 °C. This different behaviour can be used to discriminate between natural and secondary sources of atmospheric inorganic salts, as the interconversion that is observed when heating mixtures of pure salts resulted to be not relevant when heating real PM samples.

  11. A model for radiological consequences of nuclear power plant operational atmospheric releases

    International Nuclear Information System (INIS)

    Kocar, Cemil; Soekmen, Cemal Niyazi

    2009-01-01

    A dynamic dose and risk assessment model is developed to estimate radiological consequences of atmospheric emissions from nuclear power plants. Internal exposure via inhalation and ingestion, external exposure from clouds and radioactivity deposited on the ground are included in the model. The model allows to simulate interregional moves of people and multi-location food supply in the computational domain. Any long-range atmospheric dispersion model which yields radionuclide concentrations in air and on the ground at predetermined time intervals can easily be integrated into the model. The software developed is validated against radionuclide concentrations measured in different environmental media and dose values estimated after the Chernobyl accident. Results obtained using the model compare well with dose estimates and activities measured in foodstuffs and feedstuffs

  12. Climatic response to a gradual increase of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Stouffer, R.J.; Manabe, S.; Bryan, K.

    1990-01-01

    The transient response of a coupled ocean-atmosphere model to an increase of carbon dioxide has been the subject of several studies. The models used in these studies explicitly incorporate the effect of heat transport by ocean currents and are different from the model used by Hansen et al. Here the authors evaluate the climatic influence of increasing atmospheric carbon dioxide using a coupled model recently developed at the NOAA Geophysical Fluid Dynamics Laboratory. The model response exhibits a marked and unexpected interhemispheric asymmetry. In the circumpolar ocean of the southern hemisphere, a region of deep vertical mixing, the increase of surface air temperature is very slow. In the Northern hemisphere of the model, the rise of surface air temperature is faster and increases with latitude, with the exception of the northern North Atlantic, where it is relatively slow because of the weakening of the thermohaline circulation

  13. Atmospheric-pressure guided streamers for liposomal membrane disruption

    International Nuclear Information System (INIS)

    Svarnas, P.; Aleiferis, Sp.; Matrali, S. H.; Gazeli, K.; Clément, F.; Antimisiaris, S. G.

    2012-01-01

    The potential to use liposomes (LIPs) as a cellular model in order to study interactions of cold atmospheric-pressure plasma with cells is herein investigated. Cold atmospheric-pressure plasma is formed by a dielectric-barrier discharge reactor. Large multilamellar vesicle liposomes, consisted of phosphatidylcholine and cholesterol, are prepared by the thin film hydration technique, to encapsulate a small hydrophilic dye, i.e., calcein. The plasma-induced release of calcein from liposomes is then used as a measure of liposome membrane integrity and, consequently, interaction between the cold atmospheric plasma and lipid bilayers. Physical mechanisms leading to membrane disruption are suggested, based on the plasma characterization including gas temperature calculation.

  14. Release fraction of PWR after severe accidents. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, M; El-Messeiry, A M [National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Fission fragments and gases are emitted after accidents as a result of core meltdown and core concrete interactions. These aerosols are transported and fill the reactor containment. With increasing the pressure above pressure design bases, a failure of containment may occur and subsequently these aerosols will release into the external environment leading to a source term of radioactivity that affects the safety of workers and public. The amount of aerosol which escapes to the environment can be described by the release fraction which is defined as the total accumulated aerosol which initially enters the containment. The factors that affect the release fraction is studied, and the aerosol dynamics equation is used to model the release of aerosol to the outside atmosphere. These factors are containment pressure, failure time,break area, the size of aerosol particle. It found that early failure time and higher pressure increase the release fraction, also the release faction is affected by the area and the aerosol particle size. 7 figs., 2 tabs.

  15. Release fraction of PWR after severe accidents. Vol. 4

    International Nuclear Information System (INIS)

    Aziz, M.; El-Messeiry, A.M.

    1996-01-01

    Fission fragments and gases are emitted after accidents as a result of core meltdown and core concrete interactions. These aerosols are transported and fill the reactor containment. With increasing the pressure above pressure design bases, a failure of containment may occur and subsequently these aerosols will release into the external environment leading to a source term of radioactivity that affects the safety of workers and public. The amount of aerosol which escapes to the environment can be described by the release fraction which is defined as the total accumulated aerosol which initially enters the containment. The factors that affect the release fraction is studied, and the aerosol dynamics equation is used to model the release of aerosol to the outside atmosphere. These factors are containment pressure, failure time,break area, the size of aerosol particle. It found that early failure time and higher pressure increase the release fraction, also the release faction is affected by the area and the aerosol particle size. 7 figs., 2 tabs

  16. Continuous-release formulation for environmental doses to moving receptors

    International Nuclear Information System (INIS)

    Piepho, M.G.

    1981-01-01

    Atmospheric dispersion models frequently assume a puff release or several puff releases, each of which are described separately. A dispersion model should better describe a continuous release as more puffs are assumed, but the computational cost and bookkeeping difficulty increases with additional puffs. A new formulism is derived in this work which replaces the puff approximation. With the new continuous release formulation, radioactive dose calculations to moving receptors are more accurately calculated without any great additional computation. There are several advantages of a continuous release formulation. With this formulation, a dose rate to a moving receptor is calculated as a function of time. The dose-rate will increase (decrease) as the bulk of the release gets closer (farther) to (from) the receptor which is at position x(t), y(t). The receptor may follow any x, y trajectory as a function of time, and the dose rate will be calculated along the path

  17. Temporal variations in atmospheric dispersion at Hanford

    International Nuclear Information System (INIS)

    Ramsdell, J.V.; Burk, K.W.

    1990-01-01

    Climatological data are frequently used to estimate atmospheric dispersion factors for historical periods and for future releases for which adequate meteorological data are unavailable. This practice routinely leads to questions concerning the representativeness of data used. The work described here was performed to provide a basis for answering these questions at the U.S. Department of Energy's Hanford Site in eastern Washington. Atmospheric transport and diffusion near Hanford have been examined using a Lagrangian puff dispersion model and hourly meteorological data from the Hanford Meteorological Station and a network of 24 surface wind stations for a 5-yr period. Average normalized monthly concentrations were computed at 2.5-km intervals on a 31 by 31 grid from January 1983 through 1987, assuming an elevated release in the 200-East Area. Monthly average concentrations were used to determine 5-yr mean pattern and monthly mean patterns and the interannual variability about each pattern. Intra-annual and diurnal variations in dispersion factors are examined for six locations near Hanford

  18. Derived release limits for airborne effluents at TRIGA - INR Reactor

    International Nuclear Information System (INIS)

    Toma, A.; Dulama, C.; Hirica, O.; Mihai, S.; Oprea, I.

    2008-01-01

    Beginning from fulfilling the purposes of dose limitation system recommended by ICRP, and now accepted in radiation protection, this paper presents an environmental transfer model to calculate derived release limits for airborne and gaseous radioactive effluents at TRIGA-INR, 14 MW Steady State Reactor, in function on INR-Pitesti site. The methodology consists in determination of the principal exposure pathways for different groups of population and dose calculations for each radionuclide. The characterization of radionuclides transfer to environment was made using the compartmental model. The parameter transfer concept was used to describe the distribution of radionuclides between the different compartments. Atmospheric dispersion was very carefully treated, because it is the primary mechanism of the transfer of radionuclides in the environment and it determines all exposure pathways. Calculation of the atmospheric dispersion was made using ORION-II computer code based on the Gaussian plume model which takes account of site's specific climate and relief conditions. Default values recommended by literature were used to calculate some of the parameters when specific site values were not available. After identification of all transfer parameters which characterize the most important exposure pathways, the release rate corresponding to the individual dose rate limit was calculated. This maximum release rate is the derived release limit for each radionuclide and source. In the paper, the derived release limits are calculated for noble gases, radioiodine and other airborne particulate radionuclides, which can be released on the TRIGA-INR reactor stack, and are important to radiation protection. (authors)

  19. Chromium speciation in rainwater: temporal variability and atmospheric deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kieber, R.J.; Willey, J.D.; Zvalaren, S.D. [University of North Carolina at Wilmington, Wilmington, NC (United States). Dept. of Chemistry

    2002-12-15

    Chromium is released into the atmosphere by a variety of anthropogenic activities which include steel manufacturing, leather tanning, wood presentation and fossil fuel combustion. The concentrations of the various chromium species were determined in 89 rainwater samples collected in Wilmington, NC from October 1, 1999 to December 31, 2001. Volume weighted annual average concentrations of Cr{sub total}, particulate Cr, Cr(III)(aq), and Cr(VI)(aq) were 4.6, 2.2, 0.8 and 1.2 nM, respectively. There was distinct seasonal and diurnal variability in the concentrations of the various chromium species. Chromium emissions to the global atmosphere by both natural and anthropogenic sources are estimated to be 2.2 x 10{sup 9} mol/yr. Using rainwater concentration data along with other published rainwater Cr concentrations and an estimate for total global annual rain, the total global flux of chromium removed from the atmosphere via wet deposition is 2.1 x 10{sup 9} mol/yr. This represents complete removal of Cr and indicates that essentially all chromium released into the global atmosphere is removed via rain. About half this chromium is dissolved with roughly equal concentrations of toxic Cr(VI) and relatively harmless Cr(III) species. 48 refs., 4 figs., 3 tabs.

  20. Radioactive release during nuclear accidents in Chernobyl and Fukushima

    Science.gov (United States)

    Nur Ain Sulaiman, Siti; Mohamed, Faizal; Rahim, Ahmad Nabil Ab

    2018-01-01

    Nuclear accidents that occurred in Chernobyl and Fukushima have initiated many research interests to understand the cause and mechanism of radioactive release within reactor compound and to the environment. Common types of radionuclide release are the fission products from the irradiated fuel rod itself. In case of nuclear accident, the focus of monitoring will be mostly on the release of noble gases, I-131 and Cs-137. As these are the only accidents have been rated within International Nuclear Events Scale (INES) Level 7, the radioactive release to the environment was one of the critical insights to be monitored. It was estimated that the release of radioactive material to the atmosphere due to Fukushima accident was approximately 10% of the Chernobyl accident. By referring to the previous reports using computational code systems to model the release rate, the release activity of I-131 and Cs-137 in Chernobyl was significantly higher compare to Fukushima. The simulation code also showed that Chernobyl had higher release rate of both radionuclides on the day of accident. Other factors affecting the radioactive release for Fukushima and Chernobyl accidents such as the current reactor technology and safety measures are also compared for discussion.

  1. Atmospheric science and power production

    Energy Technology Data Exchange (ETDEWEB)

    Randerson, D. (ed.)

    1984-07-01

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  2. Unexpected Secoiridoid Glucosides from Manulea corymbosa

    DEFF Research Database (Denmark)

    Gousiadou, Chrysoula; Kokubun, Tetsuo; Gotfredsen, Charlotte Held

    2014-01-01

    From an extract of Manulea corymbosa were isolated four known secoiridoid glucosides (1–4), 10 new monoterpenoid esters of secologanol, namely, manuleosides A–I (5–11, 13, and 14) and dimethyl rhodanthoside A (12), and four new phenylpropanoid esters of carbocyclic iridoid glucosides, manucorymbo......, manucorymbosides I–IV (15–18). Also, the caffeoyl phenylethanoid glycoside verbascoside was isolated. The presence of secoiridoids apparently derived from loganic acid in the family Scrophulariaceae is unprecedented and greatly unexpected....

  3. Circadian variation in unexpected postoperative death

    DEFF Research Database (Denmark)

    Rosenberg, J; Pedersen, M H; Ramsing, T

    1992-01-01

    Unexpected deaths still occur following major surgical procedures. The cause is often unknown but may be cardiac or thromboembolic in nature. Postoperative ischaemia, infarction and sudden cardiac death may be triggered by episodic or constant arterial hypoxaemia, which increases during the night...... deaths occurred at night-time. These results suggest a need for further studies of sleep- and respiration-related effects on postoperative nocturnal cardiac function. The efficacy of monitoring during this apparent high-risk period should be evaluated....

  4. An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

    NARCIS (Netherlands)

    Trijssenaar-Buhre, I.J.M.; Sterkenburg, R.P.; Wijnant-Timmerman, S.I.

    2009-01-01

    Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

  5. An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

    NARCIS (Netherlands)

    Trijssenaar-Buhre, I.J.M.; Wijnant-Timmerman, S.L.

    2008-01-01

    Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

  6. New product trial, use of edibles, and unexpected highs among marijuana and hashish users in Colorado.

    Science.gov (United States)

    Allen, Jane A; Davis, Kevin C; Duke, Jennifer C; Nonnemaker, James M; Bradfield, Brian R; Farrelly, Matthew C

    2017-07-01

    This study examines the relationships between trial of new marijuana or hashish products and unexpected highs, and use of edible products and unexpected highs. We conducted an online survey of 634 adult, past-year marijuana users in Colorado. We used logistic regression models to examine the relationship between new product trial or edible use and unexpected highs. In the first year that recreational marijuana was legal in Colorado, 71.4% of respondents tried a new marijuana or hashish product, and 53.6% used an edible product. Trial of new products was associated with greater odds of experiencing an unexpected high after controlling for age, gender, education, mental health status, current marijuana or hashish use, and mean amount of marijuana or hashish consumed in the past month (OR=2.13, pmarijuana or hashish products, or use edible marijuana or hashish products, are at greater risk for an unexpected high. It is possible that some negative outcomes associated with marijuana use and unexpected highs may be averted through a better understanding of how to use product packaging to communicate with consumers. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Formulation and evaluation of gas release scenarios for the silo in Swedish Final Repository for Radioactive Waste (SFR)

    International Nuclear Information System (INIS)

    Carlsson, J.; Moreno, L.

    1992-01-01

    The Swedish Final Repository for Radioactive Waste (SFR) has been in operation since 1988 and is located in the crystalline rock, 60 m below the Baltic Sea. In the licensing procedure for the SFR the safety assessment has been complemented with a detailed scenario analysis of the performance of the repository. The scenarios include the influence on radionuclide release by gas formation and gas transport processes in the silo. The overall conclusion is that the release of most radionuclides from the silo is only marginally affected by the formation and release of gas, even for scenarios considering unexpected events. The largest effects were found for short-lived radionuclides and radionuclides that have no or low sorption ability. Except for very extreme scenarios for the silo the overall impact from repository on the environment is by far dominated by the release of radionuclides from the rock vaults. 10 refs., 6 figs

  8. Protection of atmospheric air against radioactive gas and aerosol contaminants

    International Nuclear Information System (INIS)

    Zykova, A.S.

    1984-01-01

    Measures for contamination protection of atmospheric air subdivided into active and passive ones, are considered. The active measures envisage: development and application of waste-free flowsheets, use of flowsheets which restrict formation of gaseous-aerosol discharges; application of highly efficient treatment facilities torage. Dispersion of radioactive substances, released with discharges to the atmosphere, using high stacks; development of the corresponding site-selection solutions and arrangement of sanitary protective zones belong to passive measures. Measures for protection of atmospheric air also include waste and air contamination monitoring. The measures described are considered as applied to NPPs

  9. A Status of Art-Report on the Fission Products Behavior Released from Spent Fuel at High Temperature Conditions

    International Nuclear Information System (INIS)

    Park, Geun Il; Kim, J. H.; Lee, J. W.

    2003-04-01

    The experiments on the fission products release behavior from spent fuel at high temperature assuming reactor accident conditions have been carried out at Oak Ridge Nation Laboratory of USA in HI/VI tests, CEA of France in HEVA/VERCOS tests, AEA of England and CRNL of Canada in HOX test. The VEGA program to study the fission product release behavior from LWR irradiated fuel was recently initiated at JAERI. The key parameter affecting the fission product(FP) release behavior is temperature. In addition, other parameters such as fuel oxidation, burnup, pre-transient conditions are found to affect the FP releases considerably in the earlier tests. The atmosphere conditions such as oxidizing atmosphere (steam or air) or reducing atmosphere (hydrogen) can cause significant change of FPs release and transport behavior due to chemical forms of the reactive FPs which is dependent on the oxidation potential. The effect of fuel burnup on the Kr-85 or Cs-137 release showed that the release rates of these radionuclides increased with the increase of burnup, meaning that release rates are dominated by the atomic diffusions in the grains and they are primarily a function of temperature. However, the data on FPs release behavior using higher burnups above 50,000 MWD/MTU are not so many reported up to now. This report summarizes the test results of FPs release behavior in reactor accident conditions produced from other countries mentioned above. This review and analysis on earlier studies would be useful for predicting the release characteristics of FPs from domestic spent fuel. The release rates of fission gas or FPs from spent fuel at high temperature conditions during fabrication process of dry recycling fuel were also analyzed using many data obtained from earlier tests

  10. Effect of high-oxygen and high-carbon-dioxide atmospheres on strawberry flavor and other quality traits.

    Science.gov (United States)

    Pérez, A G; Sanz, C

    2001-05-01

    The effect of high-oxygen atmospheres on strawberry flavor was studied. Strawberry fruits (Fragariax ananassa Duch. cv. Camarosa) were stored at 8 degrees C in four different atmospheres: air, 5% O(2)/20% CO(2), 80% O(2)/20% CO(2), and 90% O(2)/10% CO(2). Changes in several quality parameters were evaluated. Atmospheres combining high O(2) and high CO(2) were the most effective in preventing fungal growth and enhancing strawberry firmness. Other quality parameters such as color, titrable acidity, sugars and organic acids distribution, off-flavor development, and aroma were only mildly affected by superatmospheric O(2) levels. After one week of storage, unexpected high contents of off-flavor related compounds were found in the 80% O(2)/20% CO(2) and 90% O(2)/10% CO(2) atmospheres. Evidence of an altered ester biosynthesis was also found in fruits stored under these high-O(2) atmospheres. Data obtained suggest that stress induced by high CO(2) and stress induced by high O(2) have an additive effect on strawberry flavor alteration.

  11. Hanford 67-series: a volume of atmospheric field diffusion measurements

    International Nuclear Information System (INIS)

    Nickola, P.W.

    1977-11-01

    This volume documents atmospheric diffusion experiments carried out at the Hanford reservation during the period 1967 to 1973. A total of 103 tracer releases during 54 release periods is tabulated. Multi-tracer releases (generally from different elevations) were made during most of the experimental periods. Release heights varied from ground level to an elevation of 111 m. Tracers were sampled simultaneously on as many as 10 arcs at distances of up to 12.8 km from the tracer release point. As many as 718 field sampling locations were employed during some of the experiments. Vertical profiles of concentration were monitored on towers during 23 of the 54 release periods. Concurrent vertical profiles of mean temperature, of mean wind speed and direction, and of direction standard deviation are also tabled for elevations up to 122 m

  12. Atmospheric stability effects on potential radiological releases at a nuclear research facility in Romania: Characterising the atmospheric mixing state

    International Nuclear Information System (INIS)

    Chambers, Scott D.; Galeriu, Dan; Williams, Alastair G.; Melintescu, Anca; Griffiths, Alan D.; Crawford, Jagoda; Dyer, Leisa; Duma, Marin; Zorila, Bogdan

    2016-01-01

    A radon-based nocturnal stability classification scheme is developed for a flat inland site near Bucharest, Romania, characterised by significant local surface roughness heterogeneity, and compared with traditional meteorologically-based techniques. Eight months of hourly meteorological and atmospheric radon observations from a 60 m tower at the IFIN-HH nuclear research facility are analysed. Heterogeneous surface roughness conditions in the 1 km radius exclusion zone around the site hinder accurate characterisation of nocturnal atmospheric mixing conditions using conventional meteorological techniques, so a radon-based scheme is trialled. When the nocturnal boundary layer is very stable, the Pasquill–Gifford “radiation” scheme overestimates the atmosphere's capacity to dilute pollutants with near-surface sources (such as tritiated water vapour) by 20% compared to the radon-based scheme. Under these conditions, near-surface wind speeds drop well below 1 m s"−"1 and nocturnal mixing depths vary from ∼25 m to less than 10 m above ground level (a.g.l.). Combining nocturnal radon with daytime ceilometer data, we were able to reconstruct the full diurnal cycle of mixing depths. Average daytime mixing depths at this flat inland site range from 1200 to 1800 m a.g.l. in summer, and 500–900 m a.g.l. in winter. Using tower observations to constrain the nocturnal radon-derived effective mixing depth, we were able to estimate the seasonal range in the Bucharest regional radon flux as: 12 mBq m"−"2 s"−"1 in winter to 14 mBq m"−"2 s"−"1 in summer. - Highlights: • Site climatology accurately characterised by season and atmospheric stability class. • Comparison of "2"2"2Rn-based, Pasquill–Gifford and Richardson number stability indices. • Seasonal mixing depth estimates over the whole diurnal cycle by ceilometer and radon. • Seasonal variability in the regional radon source function well constrained.

  13. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  14. The environmental impact of radioactive releases from accidents in nuclear power reactors

    International Nuclear Information System (INIS)

    Beattie, J.R.; Griffiths, R.F.; Kaiser, G.D.; Kinchin, G.H.

    1978-01-01

    A survey of accidental releases of radioactivity from thermal and fast reactors is presented. Following a general discussion on the hazards involved, the nature of the environmental impact of radioactive releases is examined. This includes a brief review of the natural radiation background, the effect on human health of various levels of radiation and radioactivity, permissible and reference levels, and the type of hazards from both passing clouds of airbourne radioactive material and from ground deposited material. The problem of atmospheric dispersion and methods of calculations of radioactive materials in the atmosphere are examined in order for the consequences of accidental release to be analysed. National accidents and their environmental consequences are then examined. Finally there is a review of the risks to which man is always exposed because of his environment. Common and collective risks are also considered. Conclusions are reached as to the acceptibility or otherwise of the environmental impact of reactor accidents. (U.K.)

  15. Some discussions on micrometeorology and atmospheric diffusion of classic and radioactive industrial pollutions. 5

    International Nuclear Information System (INIS)

    Veverka, O.; Valenta, V.; Vlachovsky, K.

    1976-01-01

    The formulae are given expressing the atmospheric dispersion of industrial emissions released from the stacks of industrial plants and power plants. Gaussian distribution of the emissions is assumed. The behaviour of the plume is discussed and the concepts of lofting and fumigation are explained. Generalized relations are derived for the calculation of the atmospheric dispersion of gaseous wastes applicable to both high and short stack disposal and to the leakage from buildings, assuming that the source of emissions is of a point type and emissions are released continuously. (L.O.)

  16. NKS-B NordRisk II: Nuclear risk from atmospheric dispersion in Northern Europe - Summary report

    International Nuclear Information System (INIS)

    Lauritzen, B.

    2011-05-01

    The objective of the NordRisk II project has been to derive practical means for assessing the risks from long-range atmospheric dispersion of radioactive materials. An atlas over different atmospheric dispersion and deposition scenarios has been developed using historical numerical weather prediction (NWP) model data. The NWP model data covers three years spanning the climate variability associated with the North Atlantic Oscillation, and the atlas considers radioactive releases from 16 release sites in and near the Nordic countries. A statistical analysis of the long-range dispersion and deposition patterns is undertaken to quantify the mean dispersion and deposition as well as the variability. Preliminary analyses show that the large-scale atmospheric dispersion and deposition is near-isotropic, irrespective of the release site and detailed climatology, and allows for a simple parameterization of the global dispersion and deposition patterns. The atlas and the underlying data are made available in a format compatible with the ARGOS decision support system, and have been implemented in ARGOS. (Author)

  17. NKS-B NordRisk II: Nuclear risk from atmospheric dispersion in Northern Europe - Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, B. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Radiation Research Div., Roskilde (Denmark))

    2011-05-15

    The objective of the NordRisk II project has been to derive practical means for assessing the risks from long-range atmospheric dispersion of radioactive materials. An atlas over different atmospheric dispersion and deposition scenarios has been developed using historical numerical weather prediction (NWP) model data. The NWP model data covers three years spanning the climate variability associated with the North Atlantic Oscillation, and the atlas considers radioactive releases from 16 release sites in and near the Nordic countries. A statistical analysis of the long-range dispersion and deposition patterns is undertaken to quantify the mean dispersion and deposition as well as the variability. Preliminary analyses show that the large-scale atmospheric dispersion and deposition is near-isotropic, irrespective of the release site and detailed climatology, and allows for a simple parameterization of the global dispersion and deposition patterns. The atlas and the underlying data are made available in a format compatible with the ARGOS decision support system, and have been implemented in ARGOS. (Author)

  18. Modelling the release behaviour of cesium during severe fuel degradation

    International Nuclear Information System (INIS)

    Lewis, B.J.; Andre, B.; Morel, B.

    1995-01-01

    An analytical model has been applied to describe the diffusional release of fission product cesium from Zircaloy-clad fuel under high-temperature reactor accident conditions. The present treatment accounts for the influence of the atmosphere (i.e., changing oxygen potential) on the state of fuel oxidation and the release kinetics. The effects of fuel dissolution on the volatile release behaviour (under reducing conditions) is considered in terms of earlier crucible experiments and a simple model based on bubble coalescence and transport in metal pools. The model has been used to interpret the cesium release kinetics observed in steam and hydrogen experiments at the Vertical Irradiation (VI) Facility in the Oak Ridge National Laboratory and at the HEVA/VERCORS Facility in the Commissariat a l'Energie Atomique. (author)

  19. ABOUT THE POSSIBLE ROLE OF HYDROCARBON LAKES IN THE ORIGIN OF TITAN'S NOBLE GAS ATMOSPHERIC DEPLETION

    International Nuclear Information System (INIS)

    Cordier, D.; Mousis, O.; Lunine, J. I.; Lebonnois, S.; Lavvas, P.; Lobo, L. Q.; Ferreira, A. G. M.

    2010-01-01

    An unexpected feature of Titan's atmosphere is the strong depletion in primordial noble gases revealed by the Gas Chromatograph Mass Spectrometer aboard the Huygens probe during its descent on 2005 January 14. Although several plausible explanations have already been formulated, no definitive response to this issue has yet been found. Here, we investigate the possible sequestration of these noble gases in the liquid contained in lakes and wet terrains on Titan and the consequences for their atmospheric abundances. Considering the atmosphere and the liquid existing on the soil as a whole system, we compute the abundance of each noble gas relative to nitrogen. To do so, we make the assumption of thermodynamic equilibrium between the liquid and the atmosphere, the abundances of the different constituents being determined via regular solution theory. We find that xenon's atmospheric depletion can be explained by its dissolution at ambient temperature in the liquid presumably present on Titan's soil. In the cases of argon and krypton, we find that the fractions incorporated in the liquid are negligible, implying that an alternative mechanism must be invoked to explain their atmospheric depletion.

  20. radionuclides modelling dispersion of in the atmosphere for continuous discharges and accidental

    International Nuclear Information System (INIS)

    Teyeb, Malika

    2011-01-01

    The study of the dispersion of radionuclides in the atmosphere is the subject of a physical and numerical modeling of the phenomenon of dispersion. This work aims to study the atmospheric dispersion of accidental releases and continuous, from the possible establishment of a nuclear pressurized water reactor in the potential in Bizerte and Skhira.

  1. The estimation of early health effects for different combinations of release parameters and meteorological data

    International Nuclear Information System (INIS)

    Jeong, Jong Tae; Jung, Won Dea

    2001-01-01

    Variations in the number of early health effects resulting from the severe accidents of the YGN 3 and 4 nuclear power plants were examined for different combinations of release parameters and meteorological data. The release parameters and meteorological data were selected in combination to define a limited number of basic spectra characterized by release height, heat content, release time, warning time, wind speed, rainfall rate, and atmospheric stability class. Variant seasonal spectra were also defined in order to estimate the potential significance of seasonal variations as a factor determining the incidence or number of early health effects. The results show that there are large differences in consequences from spectrum to spectrum, although an equal amount and mix of radioactive material is released to the atmosphere in each case. Also, there are large differences in the estimated number of health effects from season to season due to distinct seasonal variations in meteorological combinations in Korea. Therefore, it is necessary to consider seasonal characteristics in developing optimum emergency response strategies

  2. XOQDOQ, Meteorological Evaluation of Atmospheric Nuclear Power Plant Effluents

    International Nuclear Information System (INIS)

    Sagendorf, J.F.; Goll, J.T.; Sandusky, W.F.; Eyberger, L.R.

    1990-01-01

    1 - Description of program or function: XOQDOQ was designed for meteorological evaluation of continuous and anticipated intermittent releases from commercial nuclear power reactors. It calculates annual relative effluent concentrations and average relative deposition values at locations specified by the user and at various standard radial distances and segments for downwind sectors. It also calculates these values at the specified locations for anticipated intermittent (e.g. containment or purge) releases, which occur during routine operation. The program computes an effective plume height that accounts for physical release height, aerodynamic down-wash, plume rise, and terrain features. The user may optionally select additional plume dispersion due to building wakes, plume depletion via dry deposition, and plume radioactive decay, or specify adjustments to represent non-straight line trajectories (recirculation or stagnation). 2 - Method of solution: XOQDOQ is based on the principle that diffusion of material released to the atmosphere can be described by a Gaussian distribution within the plume with transport described by a straight-line trajectory. The horizontal and vertical dispersion coefficients are empirically determined, largely from observations at or near ground level. The program implements the assumptions outlined in Section C of NRC Regulatory Guide 1.111. Long-term average values of relative effluent concentration are calculated by assuming a long-term continuous release with effluent distributed evenly across a 22-1/2 degree sector. 3 - Restrictions on the complexity of the problem - Maxima of: 30 receptor locations/receptor type, 14 wind-speed classes, 10 distances of site-specific recirculation correction factors, 8 receptor types, 7 atmospheric stability categories, 5 separate release points. XOQDOQ cannot handle multiple emission sources or plume depletion via wet deposition, or evaluate the meteorological aspects of the consequences of

  3. Lifting an unexpectedly heavy object : the effects on low-back loading and balance loss

    NARCIS (Netherlands)

    van der Burg, J C; van Dieën, J H; Toussaint, H M

    OBJECTIVE: This study evaluates the effects of lifting an unexpectedly heavy object on low-back loading and loss of balance. BACKGROUND: It is often suggested that lifting an unexpectedly heavy object may be a major risk factor for low-back pain. This may lead to an increase in muscle activation,

  4. Working memory representations persist in the face of unexpected task alterations.

    Science.gov (United States)

    Swan, Garrett; Wyble, Brad; Chen, Hui

    2017-07-01

    It is well known that information can be held in memory while performing other tasks concurrently, such as remembering a color or number during a separate visual search task. However, it is not clear what happens to stored information in the face of unexpected tasks, such as the surprise questions that are often used in experiments related to inattentional and change blindness. Does the unpredicted shift in task context cause memory representations to be cleared in anticipation of new information? To answer this question, we ran two experiments where the task unexpectedly switched partway through the experiment with a surprise question. Half of the participants were asked to report the same attribute (Exp. 1 = Identity, Exp. 2 = Color) of a target stimulus in both presurprise and postsurprise trials, while for the other half, the reported attribute switched from identity to color (Exp. 1) or vice versa (Exp. 2). Importantly, all participants had to read an unexpected set of instructions and respond differently on the surprise trial. Accuracy on the surprise trial was higher for the same-attribute groups than the different-attribute groups. Furthermore, there was no difference in reaction time on the surprise trial between the two groups. These results suggest that information participants expected to report can survive an encounter with an unexpected task. The implication is that failures to report information on a surprise trial in many experiments reflect genuine differences in memory encoding, rather than forgetting or overwriting induced by the surprise question.

  5. Investigating Initial Disclosures and Reactions to Unexpected, Positive HPV Diagnosis.

    Science.gov (United States)

    Smith, Rachel A; Hernandez, Rachael; Catona, Danielle

    2014-07-01

    Initial disclosures of health conditions are critical communication moments. Existing research focuses on disclosers; integrating confidants into studies of initial disclosures is needed. Guided by the disclosure decision-making model (DD-MM; Greene, 2009), this study examined what diagnosed persons and confidants may say when faced with unexpected test results and unexpected disclosures, respectively. Participants ( N = 151) recorded an audio-visual message for another person, after imagining that they or the other person had just received unexpected, positive HPV test results. The qualitative analysis revealed four themes: (1) impression management and social distance, (2) invisible symptoms and advice regarding future disclosures, (3) expressing and acknowledging emotional reactions, and (4) misunderstandings and lacking knowledge about HPV. These findings suggested that DD-MM may be a relevant framework for understanding not only when disclosers share, but what disclosers and confidants say in early conversations about new diagnoses. While disclosers' and confidants' messages showed marked similarities, important differences appeared. For example, confidants focused on assuaging disclosers' fear about the consequences, whereas disclosers expressed distress related to their uncertainty about the prognosis of an HPV infection and how to prepare for next steps. The discussion highlighted implications for the DD-MM, HPV disclosures, and future interventions.

  6. 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)

  7. Modified ensemble Kalman filter for nuclear accident atmospheric dispersion: prediction improved and source estimated.

    Science.gov (United States)

    Zhang, X L; Su, G F; Yuan, H Y; Chen, J G; Huang, Q Y

    2014-09-15

    Atmospheric dispersion models play an important role in nuclear power plant accident management. A reliable estimation of radioactive material distribution in short range (about 50 km) is in urgent need for population sheltering and evacuation planning. However, the meteorological data and the source term which greatly influence the accuracy of the atmospheric dispersion models are usually poorly known at the early phase of the emergency. In this study, a modified ensemble Kalman filter data assimilation method in conjunction with a Lagrangian puff-model is proposed to simultaneously improve the model prediction and reconstruct the source terms for short range atmospheric dispersion using the off-site environmental monitoring data. Four main uncertainty parameters are considered: source release rate, plume rise height, wind speed and wind direction. Twin experiments show that the method effectively improves the predicted concentration distribution, and the temporal profiles of source release rate and plume rise height are also successfully reconstructed. Moreover, the time lag in the response of ensemble Kalman filter is shortened. The method proposed here can be a useful tool not only in the nuclear power plant accident emergency management but also in other similar situation where hazardous material is released into the atmosphere. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Releases of radioactivity at the Savannah River Plant, 1954-1980

    Energy Technology Data Exchange (ETDEWEB)

    Ashley, C.; Zeigler, C. C.; Culp, P. A.

    1982-01-01

    This report contains summaries of releases of radioactivity to onsite seepage basins and to plant effluents for each year since plant startup (1954 through 1980). Releases for the years 1954 through 1959 were reassessed in 1974 and assigned release values for specific long-lived radionuclides. These long-lived radionuclides (half-lives greater than 1 year) are the only radionuclides included for the years 1954 through 1970. Since 1970 all detectable radionuclides have been included. Measured migration o radionuclides from F-, H-, and K-Area seepage basins and desorption of /sup 137/Cs from the Four Mile Creek stream bed are included in Summary B of this report. Summaries of monthly releases for 1979 and 1980 and total SRP releases by radionuclide in three categories: liquid to seepage basins, liquid to streams, and atmospheric are also included. Monthly releases for 1979 are included because the 1979 issue of this report was not published. All 1979 data are included in this report.

  9. Mathematics Placement Test: Typical Results with Unexpected Outcomes

    Science.gov (United States)

    Ingalls, Victoria

    2011-01-01

    Based on the results of a prior case-study analysis of mathematics placement at one university, the mathematics department developed and piloted a mathematics placement test. This article describes the implementation process for a mathematics placement test and further analyzes the test results for the pilot group. As an unexpected result, the…

  10. [Inventories of atmospheric arsenic emissions from coal combustion in China, 2005].

    Science.gov (United States)

    Tian, He-Zhong; Qu, Yi-Ping

    2009-04-15

    Anthropogenic arsenic (As) emitted from coal combustion is one of key trace elements leading to negative air pollution and national economy loss. It is of great significance to estimate the atmospheric arsenic emission for proposing relevant laws or regulations and selecting proper pollution control technologies. The inventories of atmospheric arsenic emissions from coal combustion in China were evaluated by adopting the emission factor method based on fuel consumption. Arsenic emission sources were firstly classified into several categories by economic sectors, combustion types and pollution control technologies. Then, according to provincial coal consumption and averaged arsenic concentration in the feed fuel, the inventories of atmospheric arsenic emission from coal combustion in China in 2005 were established. Coal outputand consumption in China in 2005 were 2,119.8 and 2,099.8 Mt, respectively. The total emissions of arsenic released into the atmosphere in 2005 in China were estimated at about 1,564.4 t, and Shandong ranked the largest province with 144.4 t arsenic release, followed by Hunan (141.1 t), Hebei (108.5 t), Henan (77.7 t), and Jiangsu (77.0 t), which were mainly concentrated in the eastern and central provinces of China. The arsenic emissions were largely emitted by industry sector (818.8 t) and thermal power generation sector (303.4 t), contributing 52.3% and 19.4% of the totals, respectively. About 375.5 t arsenic was estimated to be released into the atmosphere in the form of gas phase in China in 2005, with a share of 24% of the totals. In general, arsenic pollution control from coal combustion should be highlighted for the power and industry sectors in the whole country. However, arsenic poisoning caused by residential coal burning should also be paid great attention in some areas such as Xinjiang, Gansu, Qinghai and Guishou.

  11. The total release of xenon-133 from the Fukushima Dai-ichi nuclear power plant accident

    International Nuclear Information System (INIS)

    Stohl, Andreas; Seibert, Petra; Wotawa, Gerhard

    2012-01-01

    The accident at the Fukushima Dai-ichi nuclear power plant (FD-NPP) on 11 March 2011 released large amounts of radioactivity into the atmosphere. We determine the total emission of the noble gas xenon-133 ( 133 Xe) using global atmospheric concentration measurements. For estimating the emissions, we used three different methods: (i) using a purely observation-based multi-box model, (ii) comparisons of dispersion model results driven with GFS meteorological data with the observation data, and (iii) such comparisons with the dispersion model driven by ECMWF data. From these three methods, we have obtained total 133 Xe releases from FD-NPP of (i) 16.7 ± 1.9 EBq, (ii) 14.2 ± 0.8 EBq, and (iii) 19.0 ± 3.4 EBq, respectively. These values are substantially larger than the entire 133 Xe inventory of FD-NPP of about 12.2 EBq derived from calculations of nuclear fuel burn-up. Complete release of the entire 133 Xe inventory of FD-NPP and additional release of 133 Xe due to the decay of iodine-133 ( 133 I), which can add another 2 EBq to the 133 Xe FD-NPP inventory, is required to explain the atmospheric observations. Two of our three methods indicate even higher emissions, but this may not be a robust finding given the differences between our estimates. - Highlights: ► We determine the total release of xenon-133 from the Fukushima nuclear accident. ► We used global measurements and a box model, as well as dispersion model estimates. ► Total 133 Xe release is about 14.2-19 EBq, more than Fukushima 133 Xe inventory. ► Additional release of iodine-133 and decay into 133 Xe needed to explain results.

  12. Hazard of radioactive releases resulted from coal burning

    International Nuclear Information System (INIS)

    Gabbard, V.

    1995-01-01

    Consideration is given to the data, pointing to the fact, that coal-burning power plants release of radioactive substances, contained in gaseous wastes, is not less, than the same one of nuclear power plants. The necessity of regulating emission of these substance in atmosphere by analogy with nuclear power industry is shown. 1 fig

  13. Impact of Industrial Releases on Inshas Area

    International Nuclear Information System (INIS)

    El-Messiry, A.M.; Aly, M.M.

    1999-01-01

    Two Egyptian research reactors are located within the nuclear research center at Inshas area, 30 km north east of Cairo. This area are crowded by different industrial plants. The releases from them has a hazardous and economical effects on the research center workers and the surrounding inhabitancy. In the present work we study these effects. A meteorological regional specific data is considered all over the year, including a wind rose characterization. The study considered both normal operating conditions and an accidental releases. The results shows that there are a considerable risk due to normal releases in some areas downwind direction of the major releases, and a highly risk in areas subjected to major exposure. Regional maps of emission distribution, economical damage , pollutant concentration are obtained. The study helps to identify solutions to problems of atmospheric protection. It can be used as a decision support for the environmental, economic, and innovation planning at the national levels taking into consideration the national pollution standards and variety of existing emission sources

  14. Atmospheric modeling of Mars CH4 subsurface clathrates releases mimicking SAM and 2003 Earth-based detections

    Science.gov (United States)

    Pla-García, J.; Rafkin, S. C.

    2017-12-01

    The aim of this work is to establish the amount of mixing during all martian seasons to test whether CH4 releases inside or outside of Gale crater are consistent with MSL-SAM observations. Several modeling scenarios were configured, including instantaneous and steady releases, both inside and outside the crater. A simulation to mimic the 2003 Earth-based detections (Mumma et al. 2009 or M09) was also performed. In the instantaneous release inside Gale experiments, Ls270 was shown to be the faster mixing season when air within and outside the crater was well mixed: all tracer mass inside the crater is diluted after just 8 hours. The mixing of near surface crater air with the external environment in the rest of the year is potentially rapid but slower than Ls270.In the instantaneous release outside Gale (NW) experiment, in just 12 hours the CH4 that makes it to the MSL landing location is diluted by six orders of magnitude. The timescale of mixing in MRAMS experiments is on the order of 1 sol regardless of season. The duration of the CH4 peak observed by SAM is 100 sols. Therefore there is a steady release inside the crater, or there is a very large magnitude steady release outside the crater. In the steady release Gale experiments, CH4 flux rate from ground is 1.8 kg m-2 s-1 (derived from Gloesener et al. 2017 clathrates fluxes) and it is not predictive. In these experiments, 200 times lower CH4 values detected by SAM are modeled around MSL location. There are CH4 concentration variations of orders of magnitude depending on the hour, so timing of SAM measurements is important. With a larger (but further away) outside crater release area compared to inside, similar CH4 values around MSL are modeled, so distance to source is important. In the steady experiments mimicking M09 detection release area, only 12 times lower CH4 values detected by SAM are modeled around MSL. The highest value in the M09 modeled scenario (0.6 ppbv) is reached in Ls270. This value is the

  15. Development of computer-based function to estimate radioactive source term by coupling atmospheric model with monitoring data

    International Nuclear Information System (INIS)

    Akiko, Furuno; Hideyuki, Kitabata

    2003-01-01

    Full text: The importance of computer-based decision support systems for local and regional scale accidents has been recognized by many countries with the experiences of accidental atmospheric releases of radionuclides at Chernobyl in 1986 in the former Soviet Union. The recent increase of nuclear power plants in the Asian region also necessitates an emergency response system for Japan to predict the long-range atmospheric dispersion of radionuclides due to overseas accident. On the basis of these backgrounds, WSPEEDI (Worldwide version of System for Prediction of Environmental Emergency Dose Information) at Japan Atomic Energy Research Institute is developed to forecast long-range atmospheric dispersions of radionuclides during nuclear emergency. Although the source condition is critical parameter for accurate prediction, it is rarely that the condition can be acquired in the early stage of overseas accident. Thus, we have been developing a computer-based function to estimate radioactive source term, e.g. the release point, time and amount, as a part of WSPEEDI. This function consists of atmospheric transport simulations and statistical analysis for the prediction and monitoring of air dose rates. Atmospheric transport simulations are carried out for the matrix of possible release points in Eastern Asia and possible release times. The simulation results of air dose rates are compared with monitoring data and the best fitted release condition is defined as source term. This paper describes the source term estimation method and the application to Eastern Asia. The latest version of WSPEEDI accommodates following two models: an atmospheric meteorological model MM5 and a particle random walk model GEARN. MM5 is a non-hydrostatic meteorological model developed by the Pennsylvania State University and the National Center for Atmospheric Research (NCAR). MM5 physically calculates more than 40 meteorological parameters with high resolution in time and space based an

  16. The hazard to man of accidental releases of tritium

    International Nuclear Information System (INIS)

    Brearley, I.R.

    1985-03-01

    Some aspects of the atmospheric dispersion of tritium are discussed, followed by consideration of the dosimetric pathways. In order to assess the significance of a tritium release the doses from various pathways are estimated and compared with the doses estimated from a similar release of iodine-131. The major hazard from tritium is the ingestion of contaminated food products. For similar releases of tritium and I 131 the ingestion hazard can be comparable if the release occurs near and before the end of the harvest season. However, in the tritium release case the agricultural season influences the consequences markedly and, at other times during the year, the ingestion hazard from tritium may be approximately 20 times less. The dose from inhalation of tritium is sensitive to its chemical form and for similar releases of tritiated water and tritium gas then the dose from tritiated water is approximately 10 4 greater than the dose from tritium gas. For similar releases of tritiated water and iodine-131 then a comparison of the inhalation shows that the dose from the iodine is approximately 300 times greater. (author)

  17. Release of CFC-11 from disposal of polyurethane foam waste

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Jensen, M.H.

    2001-01-01

    The halocarbon CFC-11 has extensively been used as a blowing agent for polyurethane (PUR) insulation foams in home appliances and for residential and industrial construction. Release of CFCs is an important factor in the depletion of the ozone layer. For CFC-11 the future atmospheric concentrations...... will mainly depend on the continued release from PUR foams. Little is known about rates and time frames of the CFC release from foams especially after treatment and disposal of foam containing waste products. The CFC release is mainly controlled by slow diffusion out through the PUR. From the literature...... and by reevaluation of an old reported experiment, diffusion coefficients in the range of 0.05-1.7.10(-14) m(2) s(-1) were found reflecting differences in foam properties and experimental designs. Laboratory experiments studying the distribution of CFC in the foam and the short-term releases after shredding showed...

  18. Fate of Ammonia in the Atmosphere - A Review for Applicability to Hazardous Releases

    National Research Council Canada - National Science Library

    Renard, Jean

    2004-01-01

    .... Capture by atmospheric moisture (clouds, rain, fog), surface waters (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere...

  19. Surface - atmosphere exchange of ammonia over grazed pasture

    NARCIS (Netherlands)

    Plantaz, M.A.H.G.

    1998-01-01

    This thesis deals with the exchange of ammonia between the atmosphere and grazed pasture in an area of intensive livestock breeding. The term exchange is used because gaseous ammonia can be taken up (dry deposition) as well as released (emission) by this type of surface.
    Ammonia exchange

  20. Atmospheric Carbon Dioxide and the Global Carbon Cycle: The Key Uncertainties

    Science.gov (United States)

    Peng, T. H.; Post, W. M.; DeAngelis, D. L.; Dale, V. H.; Farrell, M. P.

    1987-12-01

    The biogeochemical cycling of carbon between its sources and sinks determines the rate of increase in atmospheric CO{sub 2} concentrations. The observed increase in atmospheric CO{sub 2} content is less than the estimated release from fossil fuel consumption and deforestation. This discrepancy can be explained by interactions between the atmosphere and other global carbon reservoirs such as the oceans, and the terrestrial biosphere including soils. Undoubtedly, the oceans have been the most important sinks for CO{sub 2} produced by man. But, the physical, chemical, and biological processes of oceans are complex and, therefore, credible estimates of CO{sub 2} uptake can probably only come from mathematical models. Unfortunately, one- and two-dimensional ocean models do not allow for enough CO{sub 2} uptake to accurately account for known releases. Thus, they produce higher concentrations of atmospheric CO{sub 2} than was historically the case. More complex three-dimensional models, while currently being developed, may make better use of existing tracer data than do one- and two-dimensional models and will also incorporate climate feedback effects to provide a more realistic view of ocean dynamics and CO{sub 2} fluxes. The instability of current models to estimate accurately oceanic uptake of CO{sub 2} creates one of the key uncertainties in predictions of atmospheric CO{sub 2} increases and climate responses over the next 100 to 200 years.

  1. The processing of unexpected positive response outcomes in the mediofrontal cortex.

    Science.gov (United States)

    Ferdinand, Nicola K; Mecklinger, Axel; Kray, Jutta; Gehring, William J

    2012-08-29

    The human mediofrontal cortex, especially the anterior cingulate cortex, is commonly assumed to contribute to higher cognitive functions like performance monitoring. How exactly this is achieved is currently the subject of lively debate but there is evidence that an event's valence and its expectancy play important roles. One prominent theory, the reinforcement learning theory by Holroyd and colleagues (2002, 2008), assigns a special role to feedback valence, while the prediction of response-outcome (PRO) model by Alexander and Brown (2010, 2011) claims that the mediofrontal cortex is sensitive to unexpected events regardless of their valence. However, paradigms examining this issue have included confounds that fail to separate valence and expectancy. In the present study, we tested the two competing theories of performance monitoring by using an experimental task that separates valence and unexpectedness of performance feedback. The feedback-related negativity of the event-related potential, which is commonly assumed to be a reflection of mediofrontal cortex activity, was elicited not only by unexpected negative feedback, but also by unexpected positive feedback. This implies that the mediofrontal cortex is sensitive to the unexpectedness of events in general rather than their valence and by this supports the PRO model.

  2. Computer code to assess accidental pollutant releases

    International Nuclear Information System (INIS)

    Pendergast, M.M.; Huang, J.C.

    1980-07-01

    A computer code was developed to calculate the cumulative frequency distributions of relative concentrations of an air pollutant following an accidental release from a stack or from a building penetration such as a vent. The calculations of relative concentration are based on the Gaussian plume equations. The meteorological data used for the calculation are in the form of joint frequency distributions of wind and atmospheric stability

  3. Gas Release as a Deformation Signal

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Radiogenic noble gases are contained in crustal rock at inter and intra granular sites. The gas composition depends on lithology, geologic history, fluid phases, and the aging effect by decay of U, Th, and K. The isotopic signature of noble gases found in rocks is vastly different than that of the atmosphere which is contributed by a variety of sources. When rock is subjected to stress conditions exceeding about half its yield strength, micro-cracks begin to form. As rock deformation progresses a fracture network evolves, releasing trapped noble gases and changing the transport properties to gas migration. Thus, changes in gas emanation and noble gas composition from rocks could be used to infer changes in stress-state and deformation. The purpose of this study has been to evaluate the effect of deformation/strain rate upon noble gas release. Four triaxial experiments were attempted for a strain rate range of %7E10-8 /s (180,000s) to %7E 10-4/s (500s); the three fully successful experiments (at the faster strain rates) imply the following: (1) helium is measurably released for all strain rates during deformation, this release is in amounts 1-2 orders of magnitude greater than that present in the air, and (2) helium gas release increases with decreasing strain rate.

  4. The choice of individual dose criterion at which to restrict agricultural produce following an unplanned release of radioactive material to atmosphere

    CERN Document Server

    Dionian, J

    1985-01-01

    In the event of an accidental release of radioactive material to atmosphere, the introduction of emergency countermeasures will be based on the need to limit the risk to individuals. However, it has been suggested that a form of cost-benefit analysis may be used as an input to decisions on the withdrawal of countermeasures, although it is recognised that these decisions may be influenced by factors other than those directly related to radiological protection. In this study, a method based on cost-benefit analysis is illustrated for assessing the optimum level of individual dose at which restrictions on agricultural production may be considered. This requires monetary values to be assigned to both the lost food production and to the health detriment, expressed as the collective effective dose equivalent commitment. It has been assumed in this analysis that food-supply restrictions are both introduced and withdrawn at the same projected level of annual individual dose. The effect on the optimum dose level of th...

  5. PROGNOSYS AND ANALYSIS OF DOSIMETRIC SITUATION AFTER EMERGENCY ATMOSPHERIC RELEASE OF NPP IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Iu. V. Bonchuk

    2009-01-01

    Full Text Available The system for the operative analysis of dosimetric situation after radiation emergencies at nuclear power plants in Ukraine (KADO is developed for decision making support. Emergency release in KADO is modelled as sequence of the discrete elements which are emitted after small time intervals that allows to take into account in calculations heterogeneity of distribution of pollution in a released cloud. Calculated predicted and avertable doses are the base information for justification of emergency and urgent countermeasures.

  6. Unexpected pathological findings in skills training and assessing skills

    NARCIS (Netherlands)

    Boendermaker, PM; Pols, J; Scherpbier, AJJA

    This article draws attention to unexpected pathological findings encountered by students and teachers when examining one another and/or simulated patients in skips training and assessment sessions. Although no literature on the subject was found it appears to be not uncommon far students and

  7. Radionuclide releases to the atmosphere from Hanford Operations, 1944--1972. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Heeb, C.M.

    1994-05-01

    The purpose of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. The first step in determining dose is to estimate the amount and timing of radionuclide releases to air and water. This report provides the air release information.

  8. Atmospheric Chemistry and Air Pollution

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Gaffney

    2003-01-01

    Full Text Available Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozone and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.

  9. Atmospheric ventilation corridors and coefficients for pollution plume ...

    African Journals Online (AJOL)

    This study presents a comparative investigation of atmospheric ventilation corridors and coefficients for gaseous pollution plume released from an isolated industrial facility into the ambient air of the host community in Ile-Ife suburb, southwest Nigeria. For the months of September to December in the year 2012 and 2013, ...

  10. Assimilation of concentration measurements for retrieving multiple point releases in atmosphere: A least-squares approach to inverse modelling

    Science.gov (United States)

    Singh, Sarvesh Kumar; Rani, Raj

    2015-10-01

    The study addresses the identification of multiple point sources, emitting the same tracer, from their limited set of merged concentration measurements. The identification, here, refers to the estimation of locations and strengths of a known number of simultaneous point releases. The source-receptor relationship is described in the framework of adjoint modelling by using an analytical Gaussian dispersion model. A least-squares minimization framework, free from an initialization of the release parameters (locations and strengths), is presented to estimate the release parameters. This utilizes the distributed source information observable from the given monitoring design and number of measurements. The technique leads to an exact retrieval of the true release parameters when measurements are noise free and exactly described by the dispersion model. The inversion algorithm is evaluated using the real data from multiple (two, three and four) releases conducted during Fusion Field Trials in September 2007 at Dugway Proving Ground, Utah. The release locations are retrieved, on average, within 25-45 m of the true sources with the distance from retrieved to true source ranging from 0 to 130 m. The release strengths are also estimated within a factor of three to the true release rates. The average deviations in retrieval of source locations are observed relatively large in two release trials in comparison to three and four release trials.

  11. The effects on the atmosphere of a major nuclear exchange

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Most of the earth's population would survive the immediate horrors of a nuclear holocaust, but what long-term climatological changes would affect their ability to secure food and shelter. This sobering report considers the effects of fine dust from ground-level detonations, of smoke from widespread fires, and of chemicals released into the atmosphere. The authors use mathematical models of atmospheric processes and data from natural situations - e.g., volcanic eruptions and arctic haze - to draw their conclusions

  12. Unexpected strong attraction in the presence of continuum bound state

    International Nuclear Information System (INIS)

    Delfino, A.; Frederico, T.

    1992-06-01

    The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)

  13. Evaluation of tecniques for controlling UF6 release clouds in the GAT environmental chamber

    International Nuclear Information System (INIS)

    Lux, C.J.

    1982-01-01

    Studies designed to characterize the reaction between UF 6 and atmospheric moisture, evaluate environmental variables of UF 6 cloud formation and ultimate cloud fate, and UF 6 release cloud control procedure have been conducted in the 1200 cu. ft. GAT environmental chamber. In earlier chamber experiments, 30 separate UF 6 release tests indicated that variations of atmospheric conditions and sample sizes had no significant effect on UO 2 F 2 particle size distribution, release cloud formation, or cloud settling rates. During the past year, numerous procedures have been evaluated for accelerating UF 6 cloud knockdown in a series of 37 environmental chamber releases. Knockdown procedures included: coarse water spray; air jet; steam spray (electrostatically charged and uncharged); carbon dioxide; Freon-12; fine water mist (uncharged); boric acid mist (charged and uncharged); and an ionized dry air stream. UF 6 hydrolysis cloud settling rates monitored by a laser/powermeter densitometer, indicated the relative effectiveness of various cloud knockdown techniques. Electrostatically charged boric acid/water mist, and electrostatically ionized dry air were both found to be very effective, knocking down the UO 2 F 2 release cloud particles in two to five minutes. Work to adapt these knockdown techniques for use under field conditions is continuing, taking into account recovery of the released uranium as well as nuclear criticality constraints

  14. Determination of the spectral behaviour of atmospheric soot using different particle models

    Science.gov (United States)

    Skorupski, Krzysztof

    2017-08-01

    In the atmosphere, black carbon aggregates interact with both organic and inorganic matter. In many studies they are modeled using different, less complex, geometries. However, some common simplification might lead to many inaccuracies in the following light scattering simulations. The goal of this study was to compare the spectral behavior of different, commonly used soot particle models. For light scattering simulations, in the visible spectrum, the ADDA algorithm was used. The results prove that the relative extinction error δCext, in some cases, can be unexpectedly large. Therefore, before starting excessive simulations, it is important to know what error might occur.

  15. An Unexpected Case of Lyme Disease in a Soldier Serving in Northern Iraq

    Science.gov (United States)

    2010-05-01

    MILITARY MEDICINE, 175,5:367,2010 An Unexpected Case of Lyme Disease in a Soldier Serving in Northern Iraq CPT Jeremy B. Fisher, SP USA *; CPT...Christopher E. Curtis, MC USAt 188143 ABSTRACT Lyme disease is a tick-transmitted disease caused by the spirochete Borrelia burgdorferi. Cases have been...Turkey.3-S We report an unexpected case of Lyme disease from Iraq. CASE REPORT A 28-year-old active duty Army male, on a deployment to northern Iraq

  16. Atmospheric dispersion modeling and radiological safety analysis for a hypothetical accident of Ghana Research Reactor -1 (GHARR-1)

    International Nuclear Information System (INIS)

    Lunguya, J. M.

    2013-06-01

    This work presents the environmental impact analysis of some selected radionuclides released from the Ghana Research Reactor- 1 (GHARR-1) after a hypothetical postulated accidents scenario. The source term was identified and generated from an inventory of radioisotopes released during the accident. Atmospheric transport model was then applied to calculate the total effective dose and how it would be distributed to different organs of the human body as a function of distance downwind. All accident scenarios were selected from GHARR-1 Safety Analysis Report. After the source term was identified the MCNPX code was used to perform the core burnup/depletion analysis. The assumption was made that the activities were released to the atmosphere under a horse design basis accident scenario. The gaussian dose calculation method was applied, coded in Hotspot, a Healthy Physics computer code. This served as the computational tool to perform the atmospheric dispersion modeling and was used to calculate radionuclide concentration at downwind location. Based upon predominant meteorological conditions at the site, the adopted strategy was to use site-specific meteorological data and dispersion modeling to analyze the hypothetical release to the environment of radionuclides and evaluate to what extent such a release may have radiological effects on the public. Final data were processed and presented as Total Effective Dose Equivalent as a function of time and distance of deposition. The results indicate that all the values of Effective dose obtained are far below the regulatory limits, making the use of the reactor safe, even in the case of worst accident scenario where all the fission products were released into the atmosphere. (au)

  17. Interpretation and modelling of fission product Ba and Mo releases from fuel

    Science.gov (United States)

    Brillant, G.

    2010-02-01

    The release mechanisms of two fission products (namely barium and molybdenum) in severe accident conditions are studied using the VERCORS experimental observations. Barium is observed to be mostly released under reducing conditions while molybdenum release is most observed under oxidizing conditions. As well, the volatility of some precipitates in fuel is evaluated by thermodynamic equilibrium calculations. The polymeric species (MoO 3) n are calculated to largely contribute to molybdenum partial pressure and barium volatility is greatly enhanced if the gas atmosphere is reducing. Analytical models of fission product release from fuel are proposed for barium and molybdenum. Finally, these models have been integrated in the ASTEC/ELSA code and validation calculations have been performed on several experimental tests.

  18. The Investigation of Unexpected Arsenic Compounds Observed in Routine Biological Monitoring Urinary Speciation Analysis

    Directory of Open Access Journals (Sweden)

    Elizabeth Leese

    2017-05-01

    Full Text Available This study investigates the identity of two unexpected arsenic species found separately in a number of urine samples sent to the Health and Safety Executive’s Health and Safety Laboratory for arsenic speciation (arsenobetaine, AB; arsenite, As3+; arsenate, As5+; monomethylarsonic acid, MMA5+; and dimethylarsinic acid, DMA5+. Micro liquid chromatography coupled to inductively coupled plasma mass spectrometry (µLC-ICP-MS and electrospray time of flight tandem mass spectrometry (ESI-QqTOF-MS/MS were used to identify the two arsenic peaks by comparison to several characterized arsenicals: arsenocholine, AC; trimethyl arsine oxide, TMAO; dimethylarsenoacetate, DMAA; dimethylarsenoethanol, DMAE; thio-dimethylarsinate, thio-DMA; thio-dimethylarsenoacetate, thio-DMAA and thio-dimethylarsenoethanol, thio-DMAE. The results from both the ICP-MS and ESI-QqTOF-MS/MS investigations indicate that the unexpected arsenic species termed peak 1 was thio-DMA. While the unexpected arsenic species termed peak 2 has yet to be identified, this investigation shows that it was not AC, TMAO, DMAA, DMAE, thio-DMA, thio-DMAA or thio-DMAE. This study demonstrates the incidence of unexpected arsenic species in both routine and non-routine urine samples from both workers and hospital patients.

  19. Process improvement methodologies uncover unexpected gaps in stroke care.

    Science.gov (United States)

    Kuner, Anthony D; Schemmel, Andrew J; Pooler, B Dustin; Yu, John-Paul J

    2018-01-01

    Background The diagnosis and treatment of acute stroke requires timed and coordinated effort across multiple clinical teams. Purpose To analyze the frequency and temporal distribution of emergent stroke evaluations (ESEs) to identify potential contributory workflow factors that may delay the initiation and subsequent evaluation of emergency department stroke patients. Material and Methods A total of 719 sentinel ESEs with concurrent neuroimaging were identified over a 22-month retrospective time period. Frequency data were tabulated and odds ratios calculated. Results Of all ESEs, 5% occur between 01:00 and 07:00. ESEs were most frequent during the late morning and early afternoon hours (10:00-14:00). Unexpectedly, there was a statistically significant decline in the frequency of ESEs that occur at the 14:00 time point. Conclusion Temporal analysis of ESEs in the emergency department allowed us to identify an unexpected decrease in ESEs and through process improvement methodologies (Lean and Six Sigma) and identify potential workflow elements contributing to this observation.

  20. Tropospheric weather influenced by solar wind through atmospheric vertical coupling downward control

    Science.gov (United States)

    Prikryl, Paul; Bruntz, Robert; Tsukijihara, Takumi; Iwao, Koki; Muldrew, Donald B.; Rušin, Vojto; Rybanský, Milan; Turňa, Maroš; Šťastný, Pavel

    2018-06-01

    Occurrence of severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system is investigated. It is observed that significant snowfall, wind and heavy rain, particularly if caused by low pressure systems in winter, tend to follow arrivals of high-speed solar wind. Previously published statistical evidence that explosive extratropical cyclones in the northern hemisphere tend to occur within a few days after arrivals of high-speed solar wind streams from coronal holes (Prikryl et al., 2009, 2016) is corroborated for the southern hemisphere. Cases of severe weather events are examined in the context of the magnetosphere-ionosphere-atmosphere (MIA) coupling. Physical mechanism to explain these observations is proposed. The leading edge of high-speed solar wind streams is a locus of large-amplitude magneto-hydrodynamic waves that modulate Joule heating and/or Lorentz forcing of the high-latitude lower thermosphere generating medium-scale atmospheric gravity waves that propagate upward and downward through the atmosphere. Simulations of gravity wave propagation in a model atmosphere using the Transfer Function Model (Mayr et al., 1990) reveal that propagating waves originating in the lower thermosphere can excite a spectrum of gravity waves in the lower atmosphere. In spite of significantly reduced amplitudes but subject to amplification upon reflection in the upper troposphere, these gravity waves can provide a lift of unstable air to release instabilities in the troposphere and initiate convection to form cloud/precipitation bands. It is primarily the energy provided by release of latent heat that leads to intensification of storms. These results indicate that vertical coupling in the atmosphere exerts downward control from solar wind to the lower atmospheric levels influencing tropospheric weather development.

  1. Radiological consequences of atmospheric releases from coal-fired power plants

    International Nuclear Information System (INIS)

    Tveten, U.

    1985-06-01

    The report deals with the individual and collective doses resulting from radioactive materials contained in the stack releases of coal-fired power plants. A critical analysis of relevant calculations in literature is given. The different reports analyzed show a very wide range in calculated doses. To a great extent these differences may be explained by the wide range in the assumptions adopted. There is also disagreement on what exposure pathways are the most important, and what nuclides contribute most to calculated doses. A most probable value of 0.5 mrem/year for the maximum individual effective dose equivalent commitment, is indicated in the report

  2. Modulation of precipitation by conditional symmetric instability release

    Science.gov (United States)

    Glinton, Michael R.; Gray, Suzanne L.; Chagnon, Jeffrey M.; Morcrette, Cyril J.

    2017-03-01

    Although many theoretical and observational studies have investigated the mechanism of conditional symmetric instability (CSI) release and associated it with mesoscale atmospheric phenomena such as frontal precipitation bands, cloud heads in rapidly developing extratropical cyclones and sting jets, its climatology and contribution to precipitation have not been extensively documented. The aim of this paper is to quantify the contribution of CSI release, yielding slantwise convection, to climatological precipitation accumulations for the North Atlantic and western Europe. Case studies reveal that CSI release could be common along cold fronts of mature extratropical cyclones and the North Atlantic storm track is found to be a region with large CSI according to two independent CSI metrics. Correlations of CSI with accumulated precipitation are also large in this region and CSI release is inferred to be occurring about 20% of the total time over depths of over 1 km. We conclude that the inability of current global weather forecast and climate prediction models to represent CSI release (due to insufficient resolution yet lack of subgrid parametrization schemes) may lead to errors in precipitation distributions, particularly in the region of the North Atlantic storm track.

  3. Digital processing method for monitoring the radioactivity of stack releases

    International Nuclear Information System (INIS)

    Vialettes, H.; Leblanc, P.; Perotin, J.P.; Lazou, J.P.

    1978-01-01

    The digital processing method proposed is adapted for data supplied by a fixed-filter detector normally used for analogue processing (integrator system). On the basis of the raw data (pulses) from the detector, the technique makes it possible to determine the rate of activity released whereas analogue processing gives only the released activity. Furthermore, the method can be used to develop alarm systems on the basis of a possible exposure rate at the point of fall-out, and by including in the program a coefficient which allows for atmospheric diffusion conditions at any given time one can improve the accuracy of the results. In order to test the digital processing method and demonstrate its advantages over analogue processing, various atmospheric contamination situations were simulated in a glove-box and analysed simultaneously, using both systems, from the pulses transmitted by the same sampling and fixed-filter detection unit. The experimental results confirm the advantages foreseen in the theoretical research. (author)

  4. Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

  5. Daily atmospheric radionuclide observations and health impact estimation before and after the Fukushima-Daiichi nuclear accident: Five-year trends by Canadian monitoring stations - Ten-year trends of atmospheric lead-210 and the correlation to atmospheric mercury in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weihua; Chen, Jing; Ungar, Kurt [Radiation Protection Bureau, Health Canada, 775 Brookfield Rd. Ottawa, K1A 1C1 (Canada)

    2014-07-01

    Mercury is a global threat to human and environmental health. Anthropogenic emissions of mercury have been larger than natural emissions since the start of the industrial age about 200 years ago. In the past decades, many studies have focused on monitoring and controlling anthropogenic emissions of mercury and their transport and transformation in the environment. In October 2013, the Minamata Convention on Mercury was formally adopted as international law. The new treaty aims to further cut mercury emissions and releases; it is the first global convention on environment and health. Coal burning for power generation and industrial use is one of the major sources of anthropogenic mercury emissions to the air. However, coal combustion processes produce significant quantities of dust containing not only mercury but also natural radionuclides that are released into the atmosphere. Like the case of mercury, those radionuclides can be transported over long distances, deposited on soil and oceans and accumulated in Arctic biota. Exposure to elevated levels of radiation is a health concern. This study analyses long-term trends of atmospheric lead-210 from Health Canada's radiological monitoring stations in the Arctic. Results are compared with ten-year records of atmospheric mercury reported by Environment Canada. A discussion is given on the correlation of long-range atmospheric transport of lead-210 and mercury from industrial sources, such as coal burning. It is expected that continuous decline of atmospheric mercury in the Arctic, especially with more and more countries signing the Minamata Convention, will result in a deceasing trend of atmospheric lead-210 from industrial sources as well. (authors)

  6. Protracted releases: inferring source terms and predicting dispersal

    International Nuclear Information System (INIS)

    Vamanu, D.V.

    1988-02-01

    Analytical solutions are given to the transport-diffusion equation for archetype, atmospheric protracted releases featuring fronts of initiation, culminations, and tails of extinction. The interplay of the fitting parameters ensures that the model accommodates a wide typology of events, nearing in the extremes the instantaneous puff of the Lagrangian models, and the continuous stack emission of the Gaussian models, respectively. (author)

  7. Dose apportionment using statistical modeling of the effluent release

    International Nuclear Information System (INIS)

    Datta, D.

    2011-01-01

    Nuclear power plants are always operated under the guidelines stipulated by the regulatory body. These guidelines basically contain the technical specifications of the specific power plant and provide the knowledge of the discharge limit of the radioactive effluent into the environment through atmospheric and aquatic route. However, operational constraints sometimes may violate the technical specification due to which there may be a failure to satisfy the stipulated dose apportioned to that plant. In a site having multi facilities sum total of the dose apportioned to all the facilities should be constrained to 1 mSv/year to the members of the public. Dose apportionment scheme basically stipulates the limit of the gaseous and liquid effluent released into the environment. Existing methodology of dose apportionment is subjective in nature that may result the discharge limit of the effluent in atmospheric and aquatic route in an adhoc manner. Appropriate scientific basis for dose apportionment is always preferable rather than judicial basis from the point of harmonization of establishing the dose apportionment. This paper presents an attempt of establishing the discharge limit of the gaseous and liquid effluent first on the basis of the existing value of the release of the same. Existing release data for a few years (for example 10 years) for any nuclear power station have taken into consideration. Bootstrap, a resampling technique, has been adopted on this data sets to generate the population which subsequently provide the corresponding population distribution of the effluent release. Cumulative distribution of the population distribution obtained is constructed and using this cumulative distribution, 95th percentile (upper bound) of the discharge limit of the radioactive effluents is computed. Dose apportioned for a facility is evaluated using this estimated upper bound of the release limit. Paper describes the detail of the bootstrap method in evaluating the

  8. A CASE STUDY OF CHLORINE TRANSPORT AND FATE FOLLOWING A LARGE ACCIDENTAL RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.; Werth, D.; Whiteside, M.; Chen, K.; Mazzola, C.

    2012-08-01

    A train derailment that occurred in Graniteville, South Carolina during the early morning hours of 06 January, 2005 resulted in the prompt release of approximately 60 tons of chlorine to the environment. Comprehensive modeling of the transport and fate of this release was performed including the characterization of the initial three-phased chlorine release, a detailed determination of the local atmospheric conditions acting to generate, disperse, and deplete the chlorine vapor cloud, the establishment of physical exchange mechanisms between the airborne vapor and local surface waters, and local aquatic dilution and mixing.

  9. The characteristics of local atmospheric circulation around the Wolsung NPP in Korea

    International Nuclear Information System (INIS)

    Lee, G.B.; Lee, M.C.; Song, Y.I.

    1998-01-01

    The transport of air pollutants in coastal regions has been known to be strongly affected by the mesoscale atmospheric circulations such as sea-land breezes. These mesoscale atmospheric circulations depend on synoptic weather conditions. In this study, a three-dimensional sea-land breeze model was developed to evaluate the effects of the sea and land breezes on the atmospheric dispersion of radioactive materials released from nuclear power plants in Korea. In the model, the hydrostatic primitive equations in the terrain-following coordinate system were used. The mesoscale atmospheric circulation simulation were carried out under various synoptic weather conditions for all seasons around the Wolsung nuclear power plant site

  10. Tritium release during inspection of reactor 'RA' at 'Vinca' institute

    International Nuclear Information System (INIS)

    Sipka, V.; Miljevic, N.; Grsic, Z.; Todorovic, D.; Radenkovic, M.

    1997-01-01

    Tritium content in daily precipitation, atmospheric water vapor inside of the reactor hall and around 'Vinca' Institute as well as in soil up to 800 m distance was monitoring during the regular inspection of the fuel channels. Tritium activity in the reactor hall air moisture was in the range from 0.022 to 6.7 MBq/m 3 . Tritium content in soil moisture between 12.7 and 530.9 Bq/l indicate a certain contamination due to tritium release in the environment, depending on the depth and distance from the place of release (author) [sr

  11. Comparison of gridded versus observation data to initialize ARAC dispersion models for the Algeciras, Spain steel mill CS-137 release

    International Nuclear Information System (INIS)

    Aluzzi, F J; Pace, J C; Pobanz, B M; Vogt, P J

    1999-01-01

    On May 30, 1998 scrap metal containing radioactive Cesium-137 (Cs-137) was accidentally melted in a furnace at the Acerinox steel mill in Algeciras, Spain. Cs-137 was released from the mill's smokestack, and spread across the western Mediterranean Sea to France and Italy and beyond. The first indication of the release was radiation levels up to 1000 times background reported by Swiss, French, and Italian authorities during the following two weeks. Initially no elevated radiation levels were detected over Spain. A release of hazardous material to the atmosphere is the type of situation the Atmospheric Release Advisory Capability (ARAC) emergency response organization was designed to address. The amount and exact time of the release were unknown, though the incident was thought to have taken place during the last week in May. Using air concentration measurements supplied by colleagues of ARAC in Spain, France, Switzerland, Italy, Sweden, Russia and the European Union, ARAC meteorologists estimated the magnitude and timing of the release (Vogt, 1999). Correctly locating the downwind footprint is the most important goal of emergency response modeling. In this study, we compare predicted results for the Algeciras event based on four wind data sources: (1) US Navy Operational Global Atmospheric Prediction System (NOGAPS) data alone, (2) surface and upper air observations alone, (3) NOGAPS data together with surface and upper air observations, and (4) forecasts from ARAC's in-house execution of the U.S. Navy Operational Regional Atmospheric Prediction System (NORAPS) (without surface or upper air observations). We compare the resulting dispersion predictions from ARAC's diagnostic dispersion modeling system to the measurements supplied by our European colleagues to determine which data source produced the best results

  12. The use of nonlinear regression analysis for integrating pollutant concentration measurements with atmospheric dispersion modeling for source term estimation

    International Nuclear Information System (INIS)

    Edwards, L.L.; Freis, R.P.; Peters, L.G.; Gudiksen, P.H.; Pitovranov, S.E.

    1993-01-01

    The accuracy associated with assessing the environmental consequences of an accidental release of radioactivity is highly dependent on the knowledge of the source term characteristics, which are generally poorly known. The development of an automated numerical technique that integrates the radiological measurements with atmospheric dispersion modeling for more accurate source term estimation is reported. Often, this process of parameter estimation is performed by an emergency response assessor, who takes an intelligent first guess at the model parameters, then, comparing the model results with whatever measurements are available, makes an intuitive, informed next guess of the model parameters. This process may be repeated any number of times until the assessor feels that the model results are reasonable in terms of the measured observations. A new approach, based on a nonlinear least-squares regression scheme coupled with the existing Atmospheric Release Advisory Capability three-dimensional atmospheric dispersion models, is to supplement the assessor's intuition with automated mathematical methods that do not significantly increase the response time of the existing predictive models. The viability of the approach is evaluated by estimation of the known SF 6 tracer release rates associated with the Mesoscale Atmospheric Transport Studies tracer experiments conducted at the Savannah River Laboratory during 1983. These 19 experiments resulted in 14 successful, separate tracer releases with sampling of the tracer plumes along the cross-plume arc situated ∼30 km from the release site

  13. Atmospheric discharge and dispersion of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant accident. Part I: Source term estimation and local-scale atmospheric dispersion in early phase of the accident

    International Nuclear Information System (INIS)

    Katata, Genki; Ota, Masakazu; Terada, Hiroaki; Chino, Masamichi; Nagai, Haruyasu

    2012-01-01

    The atmospheric release of 131 I and 137 Cs in the early phase of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident from March 12 to 14, 2011 was estimated by combining environmental data with atmospheric dispersion simulations under the assumption of a unit release rate (1 Bq h −1 ). For the simulation, WSPEEDI-II computer-based nuclear emergency response system was used. Major releases of 131 I (>10 15 Bq h −1 ) were estimated when air dose rates increased in FNPP1 during the afternoon on March 12 after the hydrogen explosion of Unit 1 and late at night on March 14. The high-concentration plumes discharged during these periods flowed to the northwest and south–southwest directions of FNPP1, respectively. These plumes caused a large amount of dry deposition on the ground surface along their routes. Overall, the spatial pattern of 137 Cs and the increases in the air dose rates observed at the monitoring posts around FNPP1 were reproduced by WSPEEDI-II using estimated release rates. The simulation indicated that air dose rates significantly increased in the south–southwest region of FNPP1 by dry deposition of the high-concentration plume discharged from the night of March 14 to the morning of March 15. - Highlights: ► Source term during the Fukushima Dai-ichi Nuclear Power Plant accident was estimated. ► Atmospheric dispersion simulation was carried out for estimation. ► Major releases were estimated in the afternoon on March 12 and the night on March 14. ► Air dose rate increased due to dry deposition during the night of March 14.

  14. Dealing with unexpected events : efficient and safe solutions to emergent repair on NPP

    Energy Technology Data Exchange (ETDEWEB)

    Liekens Massazza, I.

    2015-07-01

    Nuclear Facilities are constantly challenged with unexpected events occurring on Primary Circuit components. A solution must be deployed quickly to minimize impact on the scheduled outage duration while guaranteeing safety, quality and ALARA standards. AREVA NP has demonstrated worldwide recognized capabilities and expertise through efficient management of various unexpected forced events through the time. Turnkey packaged solutions which are proposed are based on proven technics which can be quickly adapted and qualified to the specific problem, resulting in customers’ full satisfaction. (Author)

  15. Gastric Adenomyoma: The Unexpected Mimicker

    Directory of Open Access Journals (Sweden)

    Marcela Adriana Duran Álvarez

    2017-01-01

    Full Text Available Gastric adenomyoma is a rare benign tumor composed of epithelial structures and smooth muscle stroma. Here, we report an unusual case of gastric adenomyoma mostly composed of smooth muscle that was incidentally found during a laparoscopic intervention. On radiology, it mimicked an acquired hypertrophic pyloric stenosis in an adult patient, and pathologically it resembled a pure smooth muscle hamartoma. Complete submission of the lesion for histology was necessary to find the epithelial component and make the right diagnosis. As a mimicker of benign and malignant entities, gastric adenomyoma is usually an unexpected finding after surgery. The aim of this report is to analyze this adenomyoma variant in the setting of an unexplained thickening of the gastric wall, with explanations concerning histogenesis and biological potential.

  16. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1983-05-01

    The Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE) is a program designed to obtain data necessary to evaluate atmospheric transport and diffusion models used to calculate regional population doses caused by nuclear facility emissions to the atmosphere. This experiment will significantly improve the basis for evaluating the cost effectiveness of different methods of managing airborne nuclear wastes. During the period from March 1982 through September 1982, twice daily air samples have been collected at each of five sampling stations located on a radial from the SRP to Murray Hill, NJ (1000 km). Kr-85 emitted from the F and H area chemical separations facilities is being used as a tracer to determine the transport and diffusion of atmospheric releases from the SRP. The Kr-85 concentrations in the air samples will be compared with the calculated concentrations as predicted by the transport and diffusion models. The Kr-85 data and the meteorological data are being archived and will be made available to the modeling community

  17. HOTSPOT, Field Evaluation of Radiation Release from Nuclear Accident

    International Nuclear Information System (INIS)

    2001-01-01

    1 - Description of program or function: The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes are a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. HOTSPOT programs are reasonably accurate for a timely initial assessment. More importantly, HOTSPOT codes produce a consistent output for the same input assumptions and minimize the probability of errors associated with reading a graph incorrectly or scaling a universal nomogram during an emergency. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Other programs deal with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. Additional programs estimate the dose commitment from inhalation of any one of the radionuclides listed in the database of radionuclides, calibrate a radiation survey instrument for ground survey measurements, and screening of plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Version 8 allows users to add their own custom radionuclide library and to create custom radionuclide mixtures. It also includes wet deposition to approximate the enhanced plume depletion and ground deposition due to the effects of rain. Additional release geometry options for TRITIUM RELEASE and GENERAL PLUME were added, as well as several other enhancements and improvements. See info (f1) from the main HOTSPOT menu for additional

  18. The effects on the atmosphere of a major nuclear exchange

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    Most of the earth's population would survive the immediate horrors of a nuclear holocaust, but what long-term climatological changes would affect their ability to secure food and shelter. This sobering report considers the effects of fine dust from ground-level detonations, of smoke from widespread fires, and of chemicals released into the atmosphere. The authors use mathematical models of atmospheric processes and data from natural situations - e.g., volcanic eruptions and arctic haze - to draw their conclusions.

  19. Meteorological conditions at the release site during the two tracer experiments

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.; Schneiter, D.

    1998-01-01

    The state of the boundary layer at the release site during the two tracer experiments is described, based on measurements of atmospheric turbulence carried our by a sonic anemometer, profiles of horizontal and vertical wind by a SODAR as well as frequent radiosonde releases. The boundary layer...... height is derived from radiosoundings, modelled and discussed. The study is meant as background for discussions of the tracer behaviour near the release site, and possible influence of the local meteorology at the release site on the long-range dispersion. The difference in the initial mese...... model development. It is concluded that the micrometeorological measurements are very important as background information for the understanding of plume behaviour on small as well as long scales. (C) 1998 Elsevier Science Ltd. All rights reserved....

  20. Tritium concentration reducing method in atmosphere in nuclear reactor containment facility

    International Nuclear Information System (INIS)

    Hirasawa, Yoshiya; Kigoshi, Yasutane; Yonenaga, Haruo.

    1992-01-01

    A portion of water content in an atmosphere is condensed by a condensation/evaporation device disposed in a nuclear reactor containment building and then a portion of the condensed water is evaporated in the atmosphere. A portion of hydrogen nuclides constituting the evaporated water content is subjected to isotopic exchange with tritium nuclides in the atmosphere. A portion of water content in the atmosphere applied with the isotopic exchange is condensed in the condensation/evaporation device. That is, the hydrogen nuclides in steams are applied with isotopic exchange with tritium nuclides, and steams incorporating tritium nuclides are condensed again in the condensation/evaporation device, to transfer the tritium nuclides in the atmosphere to condensed water. The condensed water is recovered without releasing the tritium nuclides to the outside of the reactor containment building, thereby enabling to reduce the tritium concentration in the atmosphere. (N.H.)

  1. Communication of Unexpected and Significant Findings on Chest Radiographs With an Automated PACS Alert System.

    LENUS (Irish Health Repository)

    Hayes, Sara A

    2014-08-01

    An integral part of realizing the enormous potential of imaging in patient care is close communication between radiologists and referring physicians. One key element of this process is the communication of unexpected significant findings. The authors examined the performance of a PACS-based alert system in the appropriate communication of reports containing unexpected significant findings to referring physicians.

  2. Environmental assessment of the Chernobyl releases in China

    International Nuclear Information System (INIS)

    Zunsu, H.

    1988-01-01

    Since Chernobyl accident, China has rapidly developed a program of emergency preparedness for nuclear accidents that the institute of radiation protection assumes the responsibility together with other institutions. For the nuclear power plants in Qinshan and in Daya Bay, a series of emergency preparedness, including the investigation of conditions and feasibility of some principal protective measures are being carried out. The research program includes atmospheric transfer and dispersion, modelling analysis of accident consequence assessment and development of a computer software system for accident consequence prediction. The strategy of China is to well organize all resources and to broaden the international cooperation. The drafting of national emergency regulations and technical guides and the establishment of specialized technical teams are in progress. In China, the accident consequence assessment is based on the specialist experiences from transfer of radioactive effluents in the atmosphere, in water and in ecological system. On May 1986 environmental assessment of the Chernobyl releases in China and environmental monitoring were carried out. Radio-nuclides released from the Chernobyl accident were detectable in all parts of country but the concentrations were very low. The results of the environmental monitoring have been presented. 7 figs., 11 tabs. (author)

  3. Impacts of heterogeneous reactions to atmospheric peroxides: Observations and budget analysis study

    Science.gov (United States)

    Qin, Mengru; Chen, Zhongming; Shen, Hengqing; Li, Huan; Wu, Huihui; Wang, Yin

    2018-06-01

    Atmospheric peroxides play important roles in atmospheric chemistry, acting as reactive oxidants and reservoirs of HOX and ROX radicals. Field measurements of atmospheric peroxides were conducted over urban Beijing from 2015 to 2016, including dust storm days, haze days and different seasons. We employed a box model based on RACM2 mechanism to conduct concentration simulation and budget analysis of hydrogen peroxide (H2O2) and peroxyacetic acid (PAA). In this study, heterogeneous reaction is found to be a significant sink for atmospheric H2O2 and PAA in urban Beijing. Here, we recommend a suitable uptake coefficient formula considering the water effect for model research of peroxides. It is found that H2O2 and PAA unexpectedly maintained considerable concentrations on haze days, even higher than that on non-haze days. This phenomenon is mainly ascribed to relatively high levels of volatile organic compounds and ozone on haze days. In addition, high levels of water vapor in pollution episode can promote not only the heterogeneous uptake to aerosol phase but also the production of H2O2. Atmospheric PAA formation is suggested to be sensitive to alkenes and NOX in urban Beijing. In particular, with the help of peroxides, sulfate formation rate from heterogeneous uptake could increase by ∼4 times on haze days, indicating the potential effect of peroxides on enhancement of aerosol oxidative property and secondary sulfate formation.

  4. Long-range transport of radioisotopes in the atmosphere and the calculation of collective dose

    International Nuclear Information System (INIS)

    Apsimon, H.M.; Goddard, A.J.H.; Wrigley, J.

    1980-01-01

    In estimating the long range (up to 1000 km) transport and dispersal of atmospheric pollutants, the meteorological conditions at the source become less relevant as the distance from the source increases, making it difficult to extrapolate to larger distances using short range modelling techniques. The MESOS model has therefore been developed to take into account the temporal and spatial changes in the atmospheric boundary layer along the trajectory of a pollutant release, including the effects of diurnal cycle and lateral dispersion in the synoptic scale windfield. The model is described together with the associated data base incorporating a year's meteorological data from synoptic stations and ships across Western Europe. A simulation of dispersal following the Windscale release of 1957 is compared with measurements. The use of the model is further illustrated by application to a hypothetical site both for routine continuous releases and short term accidental releases. This work has been carried out within the framework of a research contract between the EURATOM-CEA Association and Imperial College. (H.K.)

  5. Characteristics of CO2 release from forest soil in the mountains near Beijing.

    Science.gov (United States)

    Sun, Xiang Yang; Gao, Cheng Da; Zhang, Lin; Li, Su Yan; Qiao, Yong

    2011-04-01

    CO2 release from forest soil is a key driver of carbon cycling between the soil and atmosphere ecosystem. The rate of CO2 released from soil was measured in three forest stands (in the mountainous region near Beijing, China) by the alkaline absorption method from 2004 to 2006. The rate of CO2 released did not differ among the three stands. The CO2 release rate ranged from - 341 to 1,193 mg m(-2) h(-1), and the mean value over all three forests and sampling times was 286 mg m(-2) h(-1). CO2 release was positively correlated with soil water content and the soil temperature. Diurnally, CO2 release was higher in the day than at night. Seasonally, CO2 release was highest in early autumn and lowest in winter; in winter, negative values of CO2 release suggested that CO2 was absorbed by soil.

  6. Coupled atmosphere-soil-vegetation modelling for the assessment of the impact of atmospheric releases of heavy metals and of persistent organic pollutants at the European scale

    International Nuclear Information System (INIS)

    Queguiner, Solen

    2008-01-01

    The objective of this research thesis is to couple a model of atmospheric dispersion with a multi-environment model in order to perform impact studies related to atmospheric pollution by heavy metals and POPs (persistent organic pollutants). The author first presents the studied pollutants, their physical and chemical properties, and their effects on health. Then, he addresses the atmospheric modelling with a presentation of the used atmospheric dispersion model (POLAIR3D), and an application to heavy metals. Simulations are performed on a 4-year period in order to try to represent the inter-annual variability of atmospheric lead and cadmium concentrations. The next part reports the modelling of POPs which required the introduction of a soil model to address re-emissions. Results are compared with provided measurements. The fourth part reports the modelling of agricultural environments in the impact model, and more particularly physical processes and parameters proper to heavy metals and POPs. The author finally reports two case studies, one related to heavy metals, and the other to POPs [fr

  7. Nitrogen accumulation and release by sunn hemp, calopo, mucana and devil bean in semi-arid Ghana

    International Nuclear Information System (INIS)

    Fosu, Mathias

    2003-01-01

    Four leguminous cover crops, Calopogonium mucunoides (calopo), Mucuna prupriens (mucuna), Crotalaria juncea (sunn hemp) and Crotalaria retusa (devil bean) were evaluated on the field in Northern Ghana for N 2 fixation capacity and N release. The proportion on N derived from the atmosphere (% Ndfa) by the cover crops ranged from 64.7 to 81% with mucuna giving the highest % Ndfa and calopo the least. The total N 2 fixed ranged from 59 to 109.5 kg ha 4 with devil bean giving the largest and the least from calopo. The dry matter yield of cover crops was positively correlated with the amount of N 2 , fixed but not with the percent of N derived from the atmosphere (%Ndfa). Sunn hemp, which had the best residue quality (least per cent cellulose, lignin, C N ratio and Lignin N ratio), released 50% of its N within the first two weeks while the other cover crops with relatively poor residue quality released 25% of their N within the same period. By the end of the rainy season sunn hemp had released 90% of the residue N while the other cover crops had released 80%. (author)

  8. Autistic Traits Affect P300 Response to Unexpected Events, regardless of Mental State Inferences

    Directory of Open Access Journals (Sweden)

    Mitsuhiko Ishikawa

    2017-01-01

    Full Text Available Limited use of contextual information has been suggested as a way of understanding cognition in people with autism spectrum disorder (ASD. However, it has also been argued that individuals with ASD may have difficulties inferring others’ mental states. Here, we examined how individuals with different levels of autistic traits respond to contextual deviations by measuring event-related potentials that reflect context usage. The Autism Spectrum Quotient (AQ was used to quantify autistic-like traits in 28 university students, and 19 participants were defined as Low or High AQ groups. To additionally examine inferences about mental state, two belief conditions (with or without false belief were included. Participants read short stories in which the final sentence included either an expected or an unexpected word and rated the word’s degree of deviation from expectation. P300 waveform analysis revealed that unexpected words were associated with larger P300 waveforms for the Low AQ group, but smaller P300 responses in the High AQ group. Additionally, AQ social skill subscores were positively correlated with evaluation times in the Unexpected condition, whether a character’s belief was false or not. This suggests that autistic traits can affect responses to unexpected events, possibly because of decreased availability of context information.

  9. Potential Impact of Atmospheric Releases at Russian Far East Nuclear Submarine Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F.; Mahura, A.; Compton, K.; Brown, K.; Takano, M.; Novikov, V.; Soerensen, J. H.; Baklanov, A.

    2003-02-25

    An ''Assessment of the Impact of Russian Nuclear Fleet Operations on Far Eastern Coastal Regions'' is being performed as part of the Radiation Safety of the Biosphere Project (RAD) of the International Institute for Applied Systems Analysis (IIASA) of Laxenburg, Austria. To the best of our knowledge, this is the first comprehensive unclassified analysis of the potential impact of accidents at the Russian Far East nuclear submarine sites near Vladivostok and Petropavlovsk. We have defined the situation there based upon available information and studies commissioned by RAD in collaboration with Russian research institutes including Russian Research Center-''Kurchatov Institute'', Institute of Northern Environmental Problems and Lazurit Central Design Bureau. Further, in our original work, some in collaboration with the staff of the Danish Meteorological Institute (DMI) and members of the Japan Atomic Energy Research Institute, we have calculated the nuclide trajectories from these sites in the atmospheric boundary layer, less than 1.5 kilometers high, and determined their probability of crossing any of the nearby countries as well as Asiatic Russia. We have further determined the concentrations in each of these crossings as well as the total, dry and wet depositions of nuclides on these areas. Finally, we have calculated the doses to the Japanese Island population from typical winter airflow patterns (those most likely to cross the Islands in the minimum times), strong north winds, weak north winds and cyclonic winds for conditions similar to the Chazhma Bay criticality accident (fresh fuel) and for a criticality accident for the same type of reactor with fuel being withdrawn (spent fuel). The maximum individual committed dosages were less than 2 x 10-7 and 2 x 10-3 mSv, respectively. The long-term external doses by radionuclides deposited on the ground and the internal doses by consumption of foods were not evaluated as it is

  10. Environmental consequences of atmospheric krypton-85

    International Nuclear Information System (INIS)

    Boeck, W.L.

    1978-01-01

    This project examines the thesis that atmospheric background ionization is relevant to the understanding of weather. Projections of future world-wide use of nuclear energy imply that sufficient krypton-85 will be produced and may be released to significantly alter the natural ionization background. The scope of the project includes an assessment of krypton-85 on the electrical aspects of the atmosphere as well as the consequences of an altered electrical state of the atmosphere. The results of a first approximation model for the effects of krypton-85 on the atmosphere show that the electric field at the surface of the ocean would be reduced by about 25 percent and at a continental station by about 15 percent. At about two kilometers altitude, the electric field would be reduced by about 14 percent over the oceans and 16 percent over the land. The effects decrease quickly with increasing altitude. Analytical studies of the equations for fair weather atmospheric electricity yield solutions suitable for the interpretation of time dependent phenomena with periods longer than a few seconds. A brief analysis shows that a perfect assessment is not necessary to make an error-free decision regarding krypton-85 control measures. From the viewpoint of a decision-maker, those aspects that could swing the decision from one alternative to another are priority areas for analysis

  11. Decomposition and particle release of a carbon nanotube/epoxy nanocomposite at elevated temperatures

    International Nuclear Information System (INIS)

    Schlagenhauf, Lukas; Kuo, Yu-Ying; Bahk, Yeon Kyoung; Nüesch, Frank; Wang, Jing

    2015-01-01

    Carbon nanotubes (CNTs) as fillers in nanocomposites have attracted significant attention, and one of the applications is to use the CNTs as flame retardants. For such nanocomposites, possible release of CNTs at elevated temperatures after decomposition of the polymer matrix poses potential health threats. We investigated the airborne particle release from a decomposing multi-walled carbon nanotube (MWCNT)/epoxy nanocomposite in order to measure a possible release of MWCNTs. An experimental set-up was established that allows decomposing the samples in a furnace by exposure to increasing temperatures at a constant heating rate and under ambient air or nitrogen atmosphere. The particle analysis was performed by aerosol measurement devices and by transmission electron microscopy (TEM) of collected particles. Further, by the application of a thermal denuder, it was also possible to measure non-volatile particles only. Characterization of the tested samples and the decomposition kinetics were determined by the usage of thermogravimetric analysis (TGA). The particle release of different samples was investigated, of a neat epoxy, nanocomposites with 0.1 and 1 wt% MWCNTs, and nanocomposites with functionalized MWCNTs. The results showed that the added MWCNTs had little effect on the decomposition kinetics of the investigated samples, but the weight of the remaining residues after decomposition was influenced significantly. The measurements with decomposition in different atmospheres showed a release of a higher number of particles at temperatures below 300 °C when air was used. Analysis of collected particles by TEM revealed that no detectable amount of MWCNTs was released, but micrometer-sized fibrous particles were collected

  12. Decomposition and particle release of a carbon nanotube/epoxy nanocomposite at elevated temperatures

    Science.gov (United States)

    Schlagenhauf, Lukas; Kuo, Yu-Ying; Bahk, Yeon Kyoung; Nüesch, Frank; Wang, Jing

    2015-11-01

    Carbon nanotubes (CNTs) as fillers in nanocomposites have attracted significant attention, and one of the applications is to use the CNTs as flame retardants. For such nanocomposites, possible release of CNTs at elevated temperatures after decomposition of the polymer matrix poses potential health threats. We investigated the airborne particle release from a decomposing multi-walled carbon nanotube (MWCNT)/epoxy nanocomposite in order to measure a possible release of MWCNTs. An experimental set-up was established that allows decomposing the samples in a furnace by exposure to increasing temperatures at a constant heating rate and under ambient air or nitrogen atmosphere. The particle analysis was performed by aerosol measurement devices and by transmission electron microscopy (TEM) of collected particles. Further, by the application of a thermal denuder, it was also possible to measure non-volatile particles only. Characterization of the tested samples and the decomposition kinetics were determined by the usage of thermogravimetric analysis (TGA). The particle release of different samples was investigated, of a neat epoxy, nanocomposites with 0.1 and 1 wt% MWCNTs, and nanocomposites with functionalized MWCNTs. The results showed that the added MWCNTs had little effect on the decomposition kinetics of the investigated samples, but the weight of the remaining residues after decomposition was influenced significantly. The measurements with decomposition in different atmospheres showed a release of a higher number of particles at temperatures below 300 °C when air was used. Analysis of collected particles by TEM revealed that no detectable amount of MWCNTs was released, but micrometer-sized fibrous particles were collected.

  13. Decomposition and particle release of a carbon nanotube/epoxy nanocomposite at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Schlagenhauf, Lukas [Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Functional Polymers (Switzerland); Kuo, Yu-Ying; Bahk, Yeon Kyoung [Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Advanced Analytical Technologies (Switzerland); Nüesch, Frank [Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Functional Polymers (Switzerland); Wang, Jing, E-mail: Jing.Wang@ifu.baug.ethz.ch [Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Advanced Analytical Technologies (Switzerland)

    2015-11-15

    Carbon nanotubes (CNTs) as fillers in nanocomposites have attracted significant attention, and one of the applications is to use the CNTs as flame retardants. For such nanocomposites, possible release of CNTs at elevated temperatures after decomposition of the polymer matrix poses potential health threats. We investigated the airborne particle release from a decomposing multi-walled carbon nanotube (MWCNT)/epoxy nanocomposite in order to measure a possible release of MWCNTs. An experimental set-up was established that allows decomposing the samples in a furnace by exposure to increasing temperatures at a constant heating rate and under ambient air or nitrogen atmosphere. The particle analysis was performed by aerosol measurement devices and by transmission electron microscopy (TEM) of collected particles. Further, by the application of a thermal denuder, it was also possible to measure non-volatile particles only. Characterization of the tested samples and the decomposition kinetics were determined by the usage of thermogravimetric analysis (TGA). The particle release of different samples was investigated, of a neat epoxy, nanocomposites with 0.1 and 1 wt% MWCNTs, and nanocomposites with functionalized MWCNTs. The results showed that the added MWCNTs had little effect on the decomposition kinetics of the investigated samples, but the weight of the remaining residues after decomposition was influenced significantly. The measurements with decomposition in different atmospheres showed a release of a higher number of particles at temperatures below 300 °C when air was used. Analysis of collected particles by TEM revealed that no detectable amount of MWCNTs was released, but micrometer-sized fibrous particles were collected.

  14. Unexpected large room-temperature ferromagnetism in porous Cu{sub 2}O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xue [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050024 (China); Sun, Huiyuan, E-mail: huiyuansun@126.com [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050024 (China); Liu, Lihu; Jia, Xiaoxuan; Liu, Huiyuan [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050024 (China)

    2015-05-15

    Porous Cu{sub 2}O films have been fabricated on porous anodic alumina substrates using DC-reactive magnetron sputtering with pure Cu targets, and unexpectedly large room temperature ferromagnetism has been observed in the films. The maximum saturation magnetic moment along the out-of-plane direction was as high as 94 emu/cm{sup 3}. Photoluminescence spectra show that the ferromagnetism originates with oxygen vacancies. The ferromagnetism could be adjusted by changing the concentration of oxygen vacancies through annealing in an oxygen atmosphere. These observations suggest that the origin of the ferromagnetism is due to coupling between oxygen vacancies with local magnetic moments in the porous Cu{sub 2}O films, which can occur either directly through exchange interactions between oxygen vacancies, or through the mediation of conduction electrons. Such a ferromagnet without the presence of any ferromagnetic dopant may find applications in spintronic devices. - Highlights: • Porous Cu{sub 2}O films were deposited on porous anodic alumina (PAA) substrates. • Significant room-temperature ferromagnetism has been observed in porous Cu{sub 2}O films. • Ferromagnetism of Cu{sub 2}O films exhibited different magnetic signals with the field. • The saturation magnetization is 94 emu/cm{sup 3} with an out-of-plane.

  15. Study of atmospheric stagnation, recirculation, and ventilation potential at Narora Atomic Power Station site

    International Nuclear Information System (INIS)

    Kumar, Deepak; Kumar, Avinash; Kumar, Vimal; Rao, K.S.; Kumar, Jaivender; Ravi, P.M.

    2011-01-01

    Atmosphere is an important pathway to be considered in assessment of the environmental impact of radioactivity releases from nuclear facilities. Estimation of concentration of released effluents in air and possible ground contamination needs an understanding of relevant atmospheric dispersion. This article describes the meteorological characteristics of Narora Atomic Power Station (NAPS) site by using the integral parameters developed by Allwine and Whiteman. Meteorological data measured during the period 2006-2010 were analyzed. The integral quantities related to the occurrence of stagnation, recirculation, and ventilation characteristics were studied for NAPS site to assess the dilution potential of the atmosphere. Wind run and recirculation factors were calculated for a 24-h transport time using 5 years of hourly surface measurements of wind speed and direction. The occurrence of stagnation, recirculation, and ventilation characteristics during 2006-2010 at NAPS site is observed to be 33.8% of the time, 19.5% of the time, and 34.7% of the time, respectively. The presence of strong winds with predominant wind direction NW and WNW during winter and summer seasons leads to higher ventilation (48.1% and 44.3%) and recirculation (32.6% of the summer season). The presence of light winds and more dispersed winds during prewinter season with predominant wind directions W and WNW results in more stagnation (59.7% of the prewinter season). Thus, this study will serve as an essential meteorological tool to understand the transport mechanism of atmospheric radioactive effluent releases from any nuclear industry. (author)

  16. Many unexpected abdominal findings on staging computed tomography in patients with colorectal cancer

    DEFF Research Database (Denmark)

    Holmsted, Kim; Nørring, Keld; Laustrup, Lene Collatz

    2011-01-01

    ; an issue that was previously studied in relation to CT colonography, but not in relation to staging CT with intravenous contrast in CRC patients. The aim of the present study was to evaluate the number and significance of such unexpected findings on staging CTs in CRC patients.......Computed tomography (CT) was proven to be superior to preoperative abdominal ultrasound in the preoperative setting for detection of hepatic metastases from colorectal cancer (CRC). The higher sensitivity of CT has resulted in a number of unexpected abdominal findings of varying importance...

  17. Unexpected nitrile formation in bio-based mesoporous materials (Starbons®).

    Science.gov (United States)

    Attard, Jennifer; Milescu, Roxana; Budarin, Vitaliy; Matharu, Avtar S; Clark, James H

    2018-01-16

    The bio-based mesoporous materials made from polysaccharides, Starbons® can be modified by two different routes to give high levels of N-content, unexpectedly including significant quantities of nitrile groups which can improve the materials performance in applications including metal capture.

  18. Estimation of the environmental impact of emissions from the La Reina NEC, by atmospheric dispersion modeling

    International Nuclear Information System (INIS)

    Bustamante C, Paula M.; Ortiz R, Marcela A.

    1996-01-01

    Based on a dispersion model, an accidental release of radioactive material to the atmosphere was simulated. To evaluate the consequences of the accidental release it was used the P C COSYMA program (KfK and NRPB). The atmospheric dispersion model was MUSEMET, a segmented Gaussian plume model which requires information on meteorological conditions for a period of one year. This study was carried out to determine the plume's behavior and path, and to define protective actions. The meteorological analysis shows an airflow from the WSW and a channeling flow from the S E at night, due to topographical influences. (author)

  19. The effects of radionuclides in the atmosphere on weather, climate and environment

    International Nuclear Information System (INIS)

    Jager, D. de.

    1992-10-01

    A literature study on the effects of the released radionuclides in the atmosphere on weather, climate and environment are reported. In this report a science outlook of these effects is presented. The emissions generated by the electricity are the central issue. For the global effects the released krypton-85 (half-life time 10,78 years) which are caused by reprocessing factories would take an important role, but for local effects the releasing of short-living isotopes as xenon-133 and xenon-135 produced by nuclear reactors and radon-222 produced by mining activities must be taken into account. The production, emission and distribution of these related important isotopes are discussed, just like air-electric circuits (global), the chemistry of the atmosphere (local) and the consequences of it for the weather, climate and environment on earth. Radionuclides could affect on the development of the thunderstorm, rainfall, cloud formation, air dampness, acid- and aerosol formations and also indirect, for example, for the greenhouse effect and acid rainfall. (author). 133 refs., 22 figs., 11 tabs

  20. Derivation of release limits for a typical uranium mining and milling facility

    International Nuclear Information System (INIS)

    1985-09-01

    This report develops guidelines for calculating derived release limits (DRLs) for releases of each radionuclide belonging to the uranium-238 and thorium-232 decay chains to atmosphere, surface water and groundwater from uranium mining and milling operations in Canada. DRLs are defined as calculated limits on releases from the facility that result in radiation exposures through all environmental pathways equal to the annual effective dose equivalent limit of 0.005 Sv for stochastic effects or the annual dose equivalent limit of 0.05 Sv for non-stochastic effects in the critical group. By definition, DRLs apply to controllable radionuclide emissions which occur during the operational phase of mine/mill facilities. The report develops a steady-state environmental transfer model to determine environmental dilution and dispersion in atmosphere, surface water and groundwater between the sources at the mine and mill and the critical group receptor. Exposure pathways incorporated in the model include external exposure from immersion in the airborne plume, immersion in water, contaminated ground and contaminated shoreline sediments. Internal exposure pathways include inhalation of contaminated air and ingestion of contaminated water and terrestrial and aquatic foods

  1. Towards elucidation of the drug release mechanism from compressed hydrophilic matrices made of cellulose ethers. III. Critical use of thermodynamic parameters of activation for modeling the water penetration and drug release processes.

    Science.gov (United States)

    Ferrero, Carmen; Massuelle, Danielle; Jeannerat, Damien; Doelker, Eric

    2013-09-10

    The two main purposes of this work were: (i) to critically consider the use of thermodynamic parameters of activation for elucidating the drug release mechanism from hydroxypropyl methylcellulose (HPMC) matrices, and (ii) to examine the effect of neutral (pH 6) and acidic (pH 2) media on the release mechanism. For this, caffeine was chosen as model drug and various processes were investigated for the effect of temperature and pH: caffeine diffusion in solution and HPMC gels, and drug release from and water penetration into the HPMC tablets. Generally, the kinetics of the processes was not significantly affected by pH. As for the temperature dependence, the activation energy (E(a)) values calculated from caffeine diffusivities were in the range of Fickian transport (20-40 kJ mol⁻¹). Regarding caffeine release from HPMC matrices, fitting the profiles using the Korsmeyer-Peppas model would indicate anomalous transport. However, the low apparent E(a) values obtained were not compatible with a swelling-controlled mechanism and can be assigned to the dimensional change of the system during drug release. Unexpectedly, negative apparent E(a) values were calculated for the water uptake process, which can be ascribed to the exothermic dissolution of water into the initially dry HPMC, the expansion of the matrix and the polymer dissolution. Taking these contributions into account, the true E(a) would fall into the range valid for Fickian diffusion. Consequently, a relaxation-controlled release mechanism can be dismissed. The apparent anomalous drug release from HPMC matrices results from a coupled Fickian diffusion-erosion mechanism, both at pH 6 and 2. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Unexpected sneezing after a peribulbar injection in a patient for ...

    African Journals Online (AJOL)

    ... anaesthetic in awake patients. We present a case report of an awake elderly male who experienced unexpected continuous sneezing immediately after the removal of the needle used for the peribulbar block, which was subsequently relieved with pheniramine maleate. Keywords: peribulbar block, pheniramine maleate, ...

  3. Ground-atmosphere interactions at Gale

    Science.gov (United States)

    Renno, N. O.; Martinez, G.; Ramos, M.; Hallet, B.; Gómez, F. G.; Jun, I.; Fisk, M. R.; Gomez-Elvira, J.; Hamilton, V. E.; Mischna, M. A.; Sletten, R. S.; Martin-Torres, J.; De La Torre Juarez, M.; Vasavada, A. R.; Zorzano, M.

    2013-12-01

    We analyze variations in environmental parameters and regolith properties along Curiosity's track to determine the possible causes of an abrupt change in the thermal properties of the ground and the atmosphere observed around Sol 120, as the rover transitioned from an area of sandy soil (Rocknest) to an area of fractured bedrock terrain (Yellowknife). Curiosity is instrumented with the Rover Environmental Monitoring Station (REMS) and the Dynamic Albedo of Neutrons (DAN) sensors to measure the air temperature, the ground temperature, and the hydrogen content of the shallow subsurface along Curiosity's track. Analysis of the REMS data is used to estimate the regolith's heat budget. This analysis suggests that the abrupt decrease in the ground and atmosphere temperature and the difference between ground and air temperatures observed around Sol 120 is likely caused by an increase in the soil thermal inertia. The changes in thermal inertia have been known for some time so confirming this by the REMS package provides ground truthing. A new unexpected finding is that the regolith water content, as indicated by DAN's detection of hydrogen content, is higher in the Yellowknife soil. Another interesting finding at this site are the holes and other signs of recent geological activity in the area of fractured terrain that may reflect large volumetric variations and facilitate gas exchange between the ground and atmosphere. Near-surface volumetric changes in soil and bedrock could reflect changes in the volume of subsurface H2O, or in the partitioning of H2O among its three phases. Volume increases could also result from salt crystal growth in rock pores and soil pores associated with the adsorption of water vapor. Crystallization in pores is a significant weathering process on Earth; it could well be active on Mars. Salts also inhibits the exchange of moisture between the ground and the atmosphere, and cements the soils of arid places such as in the McMurdo Dry Valleys in

  4. Puff-plume atmospheric deposition model for use at SRP in emergency-response situations

    International Nuclear Information System (INIS)

    Garrett, A.J.; Murphy, C.E. Jr.

    1981-05-01

    An atmospheric transport and diffusion model developed for real-time calculation of the location and concentration of toxic or radioactive materials during an accidental release was improved by including deposition calculations

  5. Caesium releases under the form of silicon micro-balls during the Fukushima-Daiichi accident. Information note

    International Nuclear Information System (INIS)

    2016-01-01

    After having outlined that the most part (89 per cent) of radioactive cesium released in the atmosphere during the Fukushima accident was made under the form of silicon micro-balls which were more irradiating than other aerosols marked by cesium radioactive isotopes, this note first discusses whether these silicon micro-balls containing radioactive cesium were resulting from a specific phase of atmospheric release. It discusses the nature of these micro-balls, and discusses whether it is possible to quantitatively assess the contribution of these micro-balls to global releases and deposits. It discusses how these micro-balls could have formed, whether their formation can be associated with a specific phase of reactor degradation or with the degradation of a specific reactor. It discusses whether a specific behaviour of these micro-balls can be expected in the environment, and their possible impacts on radiological consequences

  6. Use of hydraulic and aerial mock up to study atmospheric pollution

    International Nuclear Information System (INIS)

    Facy, L.; Perrin De Brichambaut, C.; Doury, A.; Le Quinio, R.

    1962-01-01

    Fundamental studies on turbulent atmospheric diffusion of finely divided particles, cannot remain on a purely theoretical basis. Further experimental studies must be considered. - In full scale, from accidental and induced releases. - On a reduced scale, in aerodynamic wind tunnels or hydraulic water tunnels. A first set of studies on reduced scale models has been worked out according to a contract between French 'Meteorologie Nationale' and French 'Commissariat a l'Energie Atomique' and with the Collaboration of Saint-Cyr 'Institut Aerotechnique'. Essentially two kinds of results have been obtained: - The mathematical model of SUTTON for the turbulent diffusion in the atmosphere, deduced from the SUTTON theory, generally used by us, has been correctly verified, qualitatively and quantitatively whenever experiments were consistent with the theory conditions. - The quantitative assays of photographic and cinematographic visualization have given precise details on the phenomena inaccessible to calculations, due to the influence of obstacles and release conditions. - Generally, it can be asserted, that the atmospheric pollution studies are worked out by mock up experimentations and that, in some cases these experiments never can be replaced by mathematically pure models. (authors) [fr

  7. Release of chlorine from biomass at gasification conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerkman, E.; Stroemberg, B. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1997-05-01

    The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O{sub 2}, H{sub 2}O and CO{sub 2} had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO{sub 2} increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

  8. Release of chlorine from biomass at gasification conditions

    International Nuclear Information System (INIS)

    Bjoerkman, E.; Stroemberg, B.

    1997-05-01

    The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O 2 , H 2 O and CO 2 had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO 2 increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

  9. Environmental risks due to radionuclide releases Environmental Risks Due To Radionuclide Releases From The Oil And Gas Industry

    International Nuclear Information System (INIS)

    Steinhausler, F.

    2005-01-01

    Full text : Exploration and transport in the oil- and gas industry result in the release of elevated levels of natural radioactivity into the environment. This has the following impact: Due to the large volumes of water needed during the extraction of gas and oil the resulting waste water can contain increased concentration of natural radionuclides, such as radium (Ra 226) and its decay products; At the oil/water interface waste water and sludge precipitate and form scalings, containing elevated levels of radium (Ra 226); At oil- and gas extraction sites tanks and equipment can be coated with long-lived radon (Rn 222) decay products; Along oil- and gas pipelines (e.g., at compressor stations) radon (Rn 222) decay products can be deposited internally on metal surfaces, such as valves. Typical U 238-series concentration values in production water range from 8 to 42 kBq/ m3, respectively in scale from 1 to 1 000 kBq/kg. In addition, oil- and gas extraction results in significant releases of natural radionuclides to the atmosphere (Rn 222) and to the water (Th 228, Ra 226, Rn 222, Pb 210, Po 210); for example, about 0.15 GBq/a of Rn 222 are released to the atmosphere per 106 m3 of oil extracted. The disposal of large amounts of contaminated wastes (scales, sludges) represents an environmental problem for the scrap metal industry (recycling of steel pipes containing scales) and the housing industry (use of sludge for landfill below a residential area). Using data from the oil- and gas industry in Latin America, Europe and the Asia-Pacific region, the various exposure pathways are reviewed. Furthermore, the current efforts in defining a suitable regulatory framework are discussed

  10. Coupled Human-Atmosphere-System Thinking

    Science.gov (United States)

    Schmale, Julia; Chabay, Ilan

    2014-05-01

    minimize atmospheric release, but rather only complies with either climate or air quality requirements. Nor do current narratives promote behavioral change for the overall reduction of emissions (e.g., you can drive your diesel SUV as long as it has a low fuel consumption). This divide and thinking has not only been manifested in policy and regulations and hence media coverage, but has also shaped the public's general perception of this issue. There is no public conceptual understanding regarding humanity's modification of the atmosphere through the continuously and simultaneously released substances by almost any kind of activity and resulting impacts. Here, we propose a conceptual framework that provides a new perspective on the coupled human-atmosphere-system. It makes tangible the inherent linkages between the socio-economic system, the atmospheric physico-chemical changes and impacts, and legal frameworks for sustainable transformations at all levels. To implement HAS-thinking in decision and policy making, both salient disciplinary and interdisciplinary research and comprehensive science-society interactions in the form of transdisciplinary research are necessary. Societal transformations for the sake of a healthy human-atmosphere relationship are highly context dependent and require discussions of normative and value-related issues, which can only be solved through co-designed solutions. We demonstrate the importance of HAS-thinking by examples of sustainable development in the Arctic and Himalayan countries.

  11. MARC - the NRPB methodology for assessing radiological consequences of accidental releases of activity

    International Nuclear Information System (INIS)

    Clarke, R.H.; Kelly, G.N.

    1981-12-01

    The National Radiological Protection Board has developed a methodology for the assessment of the public health related consequences of accidental releases of radionuclides from nuclear facilities. The methodology consists of a suite of computer programs which predict the transfer of activity from the point of release to the atmosphere through to the population. The suite of programs is entitled MARC; Methodology for Assessing Radiological Consequences. This report describes the overall framework and philosophy utilised within MARC. (author)

  12. Impacts of a massive release of methane and hydrogen sulfide on oxygen and ozone during the late Permian mass extinction

    Science.gov (United States)

    Kaiho, Kunio; Koga, Seizi

    2013-08-01

    The largest mass extinction of animals and plants in both the ocean and on land occurred in the late Permian (252 Ma), largely coinciding with the largest flood basalt volcanism event in Siberia and an oceanic anoxic/euxinic event. We investigated the impacts of a massive release of methane (CH4) from the Siberian igneous province and the ocean and/or hydrogen sulfide (H2S) from the euxinic ocean on oxygen and ozone using photochemical model calculations. Our calculations indicated that an approximate of 14% decrease in atmospheric O2 levels would have occurred in the case of a large combined CH4 and H2S flux to the atmosphere, whereas an approximate of 8 to 10% decrease would have occurred from the CH4 flux and oxidation of all H2S in the ocean. The slight decrease in atmospheric O2 levels may have contributed to the extinction event. We demonstrate for the first time that a massive release of CH4 from the Siberian igneous province and a coincident massive release of CH4 and H2S did not cause ozone collapse. A collapse of stratospheric ozone leading to an increase in UV is not supported by the maximum model input levels for CH4 and H2S. These conclusions on O2 and O3 are correspondent to every H2S release percentages from the ocean to the atmosphere.

  13. Deployable Plume and Aerosol Release Prediction and Tracking System. Nuclear Non-Proliferation Task 1. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kleppe, John; Norris, William; Etezadi, Mehdi

    2006-07-19

    This contract was awarded in response to a proposal in which a deployable plume and aerosol release prediction and tracking system would be designed, fabricated, and tested. The system would gather real time atmospheric data and input it into a real time atmospheric model that could be used for plume predition and tracking. The system would be able to be quickly deployed by aircraft to points of interest or positioned for deployment by vehicles. The system would provide three dimensional (u, v, and w) wind vector data, inversion height measurements, surface wind information, classical weather station data, and solar radiation. The on-board real time computer model would provide the prediction of the behavior of plumes and released aerosols.

  14. Concentrations and fate of decamethylcyclopentasiloxane (D(5)) in the atmosphere.

    Science.gov (United States)

    McLachlan, Michael S; Kierkegaard, Amelie; Hansen, Kaj M; van Egmond, Roger; Christensen, Jesper H; Skjøth, Carsten A

    2010-07-15

    Decamethylcyclopentasiloxane (D(5)) is a volatile compound used in personal care products that is released to the atmosphere in large quantities. Although D(5) is currently under consideration for regulation, there have been no field investigations of its atmospheric fate. We employed a recently developed, quality assured method to measure D(5) concentration in ambient air at a rural site in Sweden. The samples were collected with daily resolution between January and June 2009. The D(5) concentration ranged from 0.3 to 9 ng m(-3), which is 1-3 orders of magnitude lower than previous reports. The measured data were compared with D(5) concentrations predicted using an atmospheric circulation model that included both OH radical and D(5) chemistry. The model was parametrized using emissions estimates and physical chemical properties determined in laboratory experiments. There was good agreement between the measured and modeled D(5) concentrations. The results show that D(5) is clearly subject to long-range atmospheric transport, but that it is also effectively removed from the atmosphere via phototransformation. Atmospheric deposition has little influence on the atmospheric fate. The good agreement between the model predictions and the field observations indicates that there is a good understanding of the major factors governing D(5) concentrations in the atmosphere.

  15. Determination of the fraction of blowing agent released from refrigerator/freezer foam after decommissioning the product

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2002-01-01

    Several halocarbons having very high global warming potential have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam revealed that most...... of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period, is highly dependent on how fine the foam is shredded. The residual blowing agent remaining after the six-week period may be very slowly released...

  16. Computer programs at SRL to evaluate environmental effects SRP operations and postulated accidental releases

    International Nuclear Information System (INIS)

    Cooper, R.E.

    1975-09-01

    Savannah River Plant operations unavoidably result in the release of some chemical and radioactive effluents to the environs. The most environmentally significant releases are gaseous effluents to the atmosphere; computer codes dealing with these atmospheric releases are discussed in this report. There is a wide variety of effluents, both chemical and radioactive, to be considered, and each must be correlated with meteorological dispersion data as a function of time to estimate the environmental effects. In addition, large inventories of toxic and radioactive materials in some facilities represent a potential for accidental releases. Accidents are postulated for these facilities, and the environmental effects of resulting releases are again evaluated by correlating with meteorological dispersion data. In accordance with AEC Regulatory Guide 23, a 2-year meteorological data base is used in performing all analyses. Due to the diversity of possible releases and the large meteorological data base, the environmental analyses are necessarily performed with the aid of a large computer facility. Several computer programs have been written to facilitate these analyses according to the type of analysis desired. The computer programs described in this report are basically of three categories: probability distributions of estimated concentrations or doses as a function of distance from a point of origin, estimates of average concentrations or doses over a specified time period such as annual averages, and some miscellaneous programs in support of the first two categories to optimize the use of the computing facility. A complete documentation of each program is included with a program listing and sample input-output

  17. Release modes and processes relevant to source-term calculations at Yucca Mountain

    International Nuclear Information System (INIS)

    Apted, M.J.

    1994-01-01

    The feasibility of permanent disposal of radioactive high-level waste (HLW) in repositories located in deep geologic formations is being studied world-wide. The most credible release pathway is interaction between groundwater and nuclear waste forms, followed by migration of radionuclide-bearing groundwater to the accessible environment. Under hydrologically unsaturated conditions, vapor transport of volatile radionuclides is also possible. The near-field encompasses the waste packages composed of engineered barriers (e.g. man-made materials, such as vitrified waste forms, corrosion-resistant containers), while the far-field includes the natural barriers (e.g. host rock, hydrologic setting). Taken together, these two subsystems define a series of multiple, redundant barriers that act to assure the safe isolation of nuclear waste. In the U.S., the Department of energy (DOE) is investigating the feasibility of safe, long-term disposal of high-level nuclear waste at the Yucca Mountain site in Nevada. The proposed repository horizon is located in non-welded tuffs within the unsaturated zone (i.e. above the water table) at Yucca Mountain. The purpose of this paper is to describe the source-term models for radionuclide release from waste packages at Yucca Mountain site. The first section describes the conceptual release modes that are relevant for this site and waste package design, based on a consideration of the performance of currently proposed engineered barriers under expected and unexpected conditions. No attempt is made to asses the reasonableness nor probability of occurrence for any specific release mode. The following section reviews the waste-form characteristics that are required to model and constrain the release of radionuclides from the waste package. The next section present mathematical models for the conceptual release modes, selected from those that have been implemented into a probabilistic total system assessment code developed for the Electric Power

  18. An evaluation of dry deposition from the long range atmospheric dispersion

    International Nuclear Information System (INIS)

    Suh, K.S.; Kim, E.H.; Hwang, W.T.; Han, M.H.; Lee, H.S.; Lee, C.W.

    2003-01-01

    The dry deposition of pollutants released into the atmosphere must be evaluated to estimate the radiological dose of terrestrial plants and foodstuffs in the ecosystem. Especially, the atmospheric dispersion and dry deposition models have been widely developed to predict and minimize the radiological damage for the surrounding environment after the TMI-2 and the Chernobyl accidents. A Lagrangian particle model for the evaluation the long-range dispersion has been firstly developed in Korea since 2001. The particle tracking method was used for the estimation of the concentration distribution of the radioactive materials released into the atmosphere. The model is designed to estimate air concentration and ground deposition at distances up to some thousands of kilometers from the source point in the horizontal direction. The turbulent motion is considered to separate the treatment of particles within the mixing layer and above the mixing layer. Also, the dispersion model is designed to receive the results of the MM5 model being operated by KMA (Korea Meteorological Administration). The test run of the long-range dispersion model has been performed in the area which covered extends from 102.47deg E to 173.34deg E and from 12.27deg N to 53.72deg N in Northeast Asia. The release point of Cs-137 assumed in the east part of the China. The long range dispersion model has been firstly developed to estimate the radiological consequences against a nuclear accident. The model will be supplemented by the comparative study using the data of the ETEX experiments. (author)

  19. The impact of sedimentary alkalinity release on the water column CO

    NARCIS (Netherlands)

    Brenner, H.; Braeckman, U.; Le Guitton, M.; Meysman, F.J.R.

    2016-01-01

    It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary

  20. Ensemble atmospheric dispersion modeling for emergency response consequence assessments

    International Nuclear Information System (INIS)

    Addis, R.P.; Buckley, R.L.

    2003-01-01

    Full text: Prognostic atmospheric dispersion models are used to generate consequence assessments, which assist decision-makers in the event of a release from a nuclear facility. Differences in the forecast wind fields generated by various meteorological agencies, differences in the transport and diffusion models themselves, as well as differences in the way these models treat the release source term, all may result in differences in the simulated plumes. This talk will address the U.S. participation in the European ENSEMBLE project, and present a perspective an how ensemble techniques may be used to enable atmospheric modelers to provide decision-makers with a more realistic understanding of how both the atmosphere and the models behave. Meteorological forecasts generated by numerical models from national and multinational meteorological agencies provide individual realizations of three-dimensional, time dependent atmospheric wind fields. These wind fields may be used to drive atmospheric dispersion (transport and diffusion) models, or they may be used to initiate other, finer resolution meteorological models, which in turn drive dispersion models. Many modeling agencies now utilize ensemble-modeling techniques to determine how sensitive the prognostic fields are to minor perturbations in the model parameters. However, the European Union programs RTMOD and ENSEMBLE are the first projects to utilize a WEB based ensemble approach to interpret the output from atmospheric dispersion models. The ensembles produced are different from those generated by meteorological forecasting centers in that they are ensembles of dispersion model outputs from many different atmospheric transport and diffusion models utilizing prognostic atmospheric fields from several different forecast centers. As such, they enable a decision-maker to consider the uncertainty in the plume transport and growth as a result of the differences in the forecast wind fields as well as the differences in the

  1. Control of accidental releases of hydrogen selenide in vented storage cabinets

    Science.gov (United States)

    Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

    1988-07-01

    Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

  2. Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics

    Science.gov (United States)

    Makarieva, A. M.; Gorshkov, V. G.; Sheil, D.; Nobre, A. D.; Li, B.-L.

    2013-01-01

    Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in the lower atmosphere. This decline occurs up to a certain height, which ranges from 3 to 4 km for surface temperatures from 10 to 30 °C. We then estimate the horizontal pressure differences associated with water vapor condensation and find that these are comparable in magnitude with the pressure differences driving observed circulation patterns. The water vapor delivered to the atmosphere via evaporation represents a store of potential energy available to accelerate air and thus drive winds. Our estimates suggest that the global mean power at which this potential energy is released by condensation is around one per cent of the global solar power - this is similar to the known stationary dissipative power of general atmospheric circulation. We conclude that condensation and evaporation merit attention as major, if previously overlooked, factors in driving atmospheric dynamics.

  3. Rancho Seco building wake effects on atmospheric diffusion

    International Nuclear Information System (INIS)

    Start, G.E.; Cate, J.H.; Dickson, C.R.; Ricks, N.R.; Ackerman, G.R.; Sagendorf, J.F.

    1977-11-01

    A series of 23 paired gaseous tracer releases at the Rancho Seco Nuclear Power Station in 1975 was the third of several tests designed to investigate the diffusion characteristics of the atmosphere under conditions of low windspeed and temperature inversion. This test also evaluated the effects of flow around buildings upon dilution of pollutants. Gaseous tracers were laterally dispersed about six times more than the expected amounts from Pasquill--Gifford curves of sigma-y. Most of this increase could be related to observed variance of the horizontal wind direction (meandering). For ground-level releases the effective sigma-z values were 16 times greater than the corresponding values from the Pasquill--Gifford curves. Measured ground-level axial concentrations were about 75 times smaller than predicted by the Gaussian diffusion equation for a ground-level release when Pasquill--Gifford values of sigma-y and sigma-z were used

  4. ESTE AI (Annual Impacts) - the program for calculation of radiation doses caused by effluents in routine releases to the atmosphere and to the hydrosphere

    International Nuclear Information System (INIS)

    Carny, P.; Suchon, D.; Smejkalova, E.; Fabova, V.

    2009-01-01

    ESTE AI is a program for calculation of radiation doses caused by effluents in routine releases to the atmosphere and to the hydrosphere. Doses to the members of critical groups of inhabitants in the vicinity of NPP are calculated and as a result, critical group is determined. The program enables to calculate collective doses as well. Collective doses to the inhabitants living in the vicinity of the NPP are calculated. ESTE AI calculates doses to the whole population of Slovakia from the effluents of the specific plant. In this calculation, global nuclides are included and assumed, as well. The program enables to calculate and to document beyond-border radiological impacts of effluents caused by routine operation of NPP. ESTE AI was approved by the 'Public Health Authority of the Slovak Republic' and is used as legal instrument by Slovenske elektrarne a.s., NPP Bohunice. (authors)

  5. ESTE AI (Annual Impacts) - the program for calculation of radiation doses caused by effluents in routine releases to the atmosphere and to the hydrosphere

    International Nuclear Information System (INIS)

    Carny, P.; Suchon, D.; Smejkalova, E.; Fabova, V.

    2008-01-01

    ESTE AI is a program for calculation of radiation doses caused by effluents in routine releases to the atmosphere and to the hydrosphere. Doses to the members of critical groups of inhabitants in the vicinity of NPP are calculated and as a result, critical group is determined. The program enables to calculate collective doses as well. Collective doses to the inhabitants living in the vicinity of the NPP are calculated. ESTE AI calculates doses to the whole population of Slovakia from the effluents of the specific plant. In this calculation, global nuclides are included and assumed, as well. The program enables to calculate and to document beyond-border radiological impacts of effluents caused by routine operation of NPP. ESTE AI was approved by the 'Public Health Authority of the Slovak Republic' and is used as legal instrument by Slovenske elektrarne a.s., NPP Bohunice. (authors)

  6. When an Object Appears Unexpectedly: Object Circumvention in Adults.

    Science.gov (United States)

    Wilmut, Kate; Du, Wenchong; Barnett, Anna L

    2017-01-01

    Obstacles often appear unexpectedly in our pathway and these require us to make immediate adjustments. Despite how regularly we encounter such situations only few studies have considered how we adjust to unexpected obstacles in the pathway that require us to walk around them. The authors considered how adults adjust to the possibility of an obstacle appearing and then also how foot placement is adjusted to circumvent an obstacle. Fifteen healthy adults walked down an 11-m walkway, initially they were told this was a clear pathway and nothing in the environment would change (no gate), they then performed a series of trials in which a gate may (gate close) or may not (gate open) partially obstruct their pathway. The authors found that mediolateral trunk velocity and acceleration was significantly increased when there was the possibility of an obstacle but before the obstacle appeared. This demonstrates an adaptive walking strategy that seems to enable healthy young adults to successfully circumvent obstacles. The authors also categorized foot placement adjustments and found that adults favored making shorter and wider steps away from the obstacle. They suggest this combination of adjustments allows participants to maintain stability while successfully circumventing the obstacle.

  7. Frequentie en oorzaak van onverwachte allergische reacties op voedsel [Frequency and cause of unexpected allergic reactions to food

    NARCIS (Netherlands)

    Michelsen-Huisman, A.D.; Os-Medendorp, H. van; Versluis, A.; Kruizinga, A.G.; Castenmiller, J.J.M.; Noteborn, H.P.J.M.; Houben, G.F.; Knulst, A.C.

    2014-01-01

    Unexpected reactions occur in patients with food allergy, but frequency data are scare. This prospective study investigates the frequency, severity and causes of unexpected allergic reactions to food in adults with a doctor's diagnosed food allergy. Participants complete an online questionnaire

  8. Soil HONO Emissions and Its Potential Impact on the Atmospheric Chemistry and Nitrogen Cycle

    Science.gov (United States)

    Su, H.; Chen, C.; Zhang, Q.; Poeschl, U.; Cheng, Y.

    2014-12-01

    Hydroxyl radicals (OH) are a key species in atmospheric photochemistry. In the lower atmosphere, up to ~30% of the primary OH radical production is attributed to the photolysis of nitrous acid (HONO), and field observations suggest a large missing source of HONO. The dominant sources of N(III) in soil, however, are biological nitrification and denitrification processes, which produce nitrite ions from ammonium (by nitrifying microbes) as well as from nitrate (by denitrifying microbes). We show that soil nitrite can release HONO and explain the reported strength and diurnal variation of the missing source. The HONO emissions rates are estimated to be comparable to that of nitric oxide (NO) and could be an important source of atmospheric reactive nitrogen. Fertilized soils appear to be particularly strong sources of HONO. Thus, agricultural activities and land-use changes may strongly influence the oxidizing capacity of the atmosphere. A new HONO-DNDC model was developed to simulate the evolution of HONO emissions in agriculture ecosystems. Because of the widespread occurrence of nitrite-producing microbes and increasing N and acid deposition, the release of HONO from soil may also be important in natural environments, including forests and boreal regions. Reference: Su, H. et al., Soil Nitrite as a Source of Atmospheric HONO and OH Radicals, Science, 333, 1616-1618, 10.1126/science.1207687, 2011.

  9. Tests on the release of fission and activation products during core meltdown

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, H; Krause, W; Wild, H

    1976-01-01

    The first available results are related to tests in which the release of the main components of the core melt, namely the steel, zircaloy and uranium components, was determined using ThO/sub 2/ crucibles. The release products are dispersed onto the pipe walls of the transport system and the measuring filters which were installed at about 1 m distance from the melt crucibles. Of these, only the precipitates on the filters have been analyzed so far. In the tests under air, the release was clearly dependent on the maximum temperature reached. The release values for Mo and Mn were the highest with 5-10%; uranium with 0.1% on the other hand, was the lowest. In a steam atmosphere over the melt, the analysis of the filter precipitates for all elements gave considerably lower values than with the tests in air.

  10. Consumption of energy and release of entropy into the biosphere

    International Nuclear Information System (INIS)

    Deutscher, G.

    2014-01-01

    The short-term threat on humanity is not the shortage of energy but rather the contamination of the environment. The concept of entropy is useful to assess the impact of humane activities on the environment. During most of earth history the increase of entropy was more than compensated by the energy brought by the sun. Today the intensive use of fossil fuels has reversed the trend: the biosphere entropy increases as CO 2 piles up in the atmosphere. The release of entropy is linked to the amount of energy we consume and to the efficiency of the process we use to produce it. Nuclear power plants release entropy as low-temperature heat but this amount of entropy is far less than the entropy released by fossil-fuel power plants under the form of CO 2 . (A.C.)

  11. Responding In-the-Moment: Learning to Prepare for the Unexpected

    Science.gov (United States)

    Mason, John

    2015-01-01

    Becoming aware of something unexpected can be a form of awakening: sharpening attention, enriching noticing, opening up fresh possibilities of action, and educating awareness so as to enable a sensitive response to similar situations in the future. However it can also trigger tunnel vision (few if any actions available) or freezing (no actions…

  12. Unexpected brain finding in pre-autopsy postmortem CT.

    Science.gov (United States)

    Chatzaraki, Vasiliki; Bolliger, Stephan A; Thali, Michael J; Eggert, Sebastian; Ruder, Thomas D

    2017-09-01

    A case is presented in which pre-autopsy postmortem computed tomography (PMCT) revealed an unexpected brain abscess with a related frontal sinusitis and an erosion of the posterior wall of the frontal sinus. PMCT findings enabled the forensic pathologists to adapt protective measures during autopsy and protect their health from infection. Pre-autopsy PMCT has been also useful in the early differential diagnosis procedure. The complementary use of postmortem imaging and autopsy can improve the quality of forensic death investigations.

  13. Convergence monitoring of Markov chains generated for inverse tracking of unknown model parameters in atmospheric dispersion

    International Nuclear Information System (INIS)

    Kim, Joo Yeon; Ryu, Hyung Joon; Jung, Gyu Hwan; Lee, Jai Ki

    2011-01-01

    The dependency within the sequential realizations in the generated Markov chains and their reliabilities are monitored by introducing the autocorrelation and the potential scale reduction factor (PSRF) by model parameters in the atmospheric dispersion. These two diagnostics have been applied for the posterior quantities of the release point and the release rate inferred through the inverse tracking of unknown model parameters for the Yonggwang atmospheric tracer experiment in Korea. The autocorrelations of model parameters are decreasing to low values approaching to zero with increase of lag, resulted in decrease of the dependencies within the two sequential realizations. Their PSRFs are reduced to within 1.2 and the adequate simulation number recognized from these results. From these two convergence diagnostics, the validation of Markov chains generated have been ensured and PSRF then is especially suggested as the efficient tool for convergence monitoring for the source reconstruction in atmospheric dispersion. (author)

  14. Cadmium release from a reprocessing electrorefiner falling over

    Energy Technology Data Exchange (ETDEWEB)

    Solbrig, Charles W., E-mail: Charles.solbrig@inl.gov [Batelle Energy Alliance, Idaho National Laboratory, PO Box 2528, Idaho Falls, ID 83404 (United States); Pope, Chad L. [Batelle Energy Alliance, Idaho National Laboratory, PO Box 2528, Idaho Falls, ID 83404 (United States)

    2013-02-15

    Highlights: ► We model an accident in a nuclear fuel processing facility caused by an earthquake. ► The earthquake causes the argon cell to breach and the electrorefiner to tip over. ► Cadmium is spilled and a cathode falls on the cadmium and starts to burn. ► Cadmium can be transported to people in the building, the site, and the public. ► The results show negligible doses to all persons except in one low probability case. -- Abstract: The possible biological consequences of a release of cadmium due to a design basis earthquake in the Idaho Nuclear Laboratory's nuclear fuel reprocessing cell are evaluated. The facility is designed to withstand the design basis earthquake except for some non-seismically qualified feedthroughs. The earthquake is hypothesized to breach these feedthroughs (allowing air into the argon atmosphere processing cell) and cause the MK-IV electrorefiner (ER) in the cell to tip over or split and spill its contents of fission product laden salt and cadmium. In addition, the uranium dendrite product cathode is assumed to fall on the cadmium and burn. The heat from the burning cathode results in release of cadmium vapor into the cell atmosphere. Ingestion and inhalation of a sufficient concentration of cadmium for a critical time period can cause irreversible health effects or death. The release of the small quantity of fission products, analyzed elsewhere, results in negligible doses. Analysis reported here shows there is no danger to the general public by the cadmium release or to on-site workers except in one low probability case. This one case requires a fivefold failure where the safety exhaust system fails just after the 4% oxygen concentration combustion limit in the cell is reached. Failure of the SES allows oscillatory inflow and outflow (and hence cadmium outflow) from the cell due to gravity. The dose to a worker in the basement exceeds the mortality limit in this one event if the worker does not leave the basement.

  15. Cadmium release from a reprocessing electrorefiner falling over

    International Nuclear Information System (INIS)

    Solbrig, Charles W.; Pope, Chad L.

    2013-01-01

    Highlights: ► We model an accident in a nuclear fuel processing facility caused by an earthquake. ► The earthquake causes the argon cell to breach and the electrorefiner to tip over. ► Cadmium is spilled and a cathode falls on the cadmium and starts to burn. ► Cadmium can be transported to people in the building, the site, and the public. ► The results show negligible doses to all persons except in one low probability case. -- Abstract: The possible biological consequences of a release of cadmium due to a design basis earthquake in the Idaho Nuclear Laboratory's nuclear fuel reprocessing cell are evaluated. The facility is designed to withstand the design basis earthquake except for some non-seismically qualified feedthroughs. The earthquake is hypothesized to breach these feedthroughs (allowing air into the argon atmosphere processing cell) and cause the MK-IV electrorefiner (ER) in the cell to tip over or split and spill its contents of fission product laden salt and cadmium. In addition, the uranium dendrite product cathode is assumed to fall on the cadmium and burn. The heat from the burning cathode results in release of cadmium vapor into the cell atmosphere. Ingestion and inhalation of a sufficient concentration of cadmium for a critical time period can cause irreversible health effects or death. The release of the small quantity of fission products, analyzed elsewhere, results in negligible doses. Analysis reported here shows there is no danger to the general public by the cadmium release or to on-site workers except in one low probability case. This one case requires a fivefold failure where the safety exhaust system fails just after the 4% oxygen concentration combustion limit in the cell is reached. Failure of the SES allows oscillatory inflow and outflow (and hence cadmium outflow) from the cell due to gravity. The dose to a worker in the basement exceeds the mortality limit in this one event if the worker does not leave the basement

  16. Modelling accidental releases of tritium in the environment: application as an excel spreadsheet

    International Nuclear Information System (INIS)

    Le Dizes, S.; Tamponnet, C.

    2004-01-01

    An application as an Excel spreadsheet of the simplified modelling approach of tritium transfer in the environment developed by Tamponnet (2002) is presented. Based on the use of growth models of biological systems (plants, animals, etc.), the two-pool model (organic tritium and tritiated water) that was developed estimates the concentration of tritium within the different compartments of the food chain and in fine the dose to man by ingestion in the case of a chronic or accidental release of tritium in a river or the atmosphere. Data and knowledge have been implemented on Excel using the object-oriented programming language VisualBasic (Microsoft Visual Basic 6.0). The structure of the conceptual model and the Excel sheet are first briefly exposed. A numerical application of the model under a scenario of an accidental release of tritium in the atmosphere is then presented. Simulation results and perspectives are discussed. (author)

  17. Observation of ultraslow stress release in silicon nitride films on CaF2

    International Nuclear Information System (INIS)

    Guo, Tianyi; Deen, M. Jamal; Xu, Changqing; Fang, Qiyin; Selvaganapathy, P. Ravi; Zhang, Haiying

    2015-01-01

    Silicon nitride thin films are deposited by plasma-enhanced chemical vapor deposition on (100) and (111) CaF 2 crystalline substrates. Delaminated wavy buckles formed during the release of internal compressive stress in the films and the stress releasing processes are observed macroscopically and microscopically. The stress release patterns start from the substrate edges and propagate to the center along defined directions aligned with the crystallographic orientations of the substrate. The stress releasing velocity of SiN x film on (111) CaF 2 is larger than that of SiN x film with the same thickness on (100) CaF 2 . The velocities of SiN x film on both (100) and (111) CaF 2 increase with the film thickness. The stress releasing process is initiated when the films are exposed to atmosphere, but it is not a chemical change from x-ray photoelectron spectroscopy

  18. Controlled release of ethylene via polymeric films for food packaging

    Science.gov (United States)

    Pisano, Roberto; Bazzano, Marco; Capozzi, Luigi Carlo; Ferri, Ada; Sangermano, Marco

    2015-12-01

    In modern fruit supply chain a common method to trigger ripening is to keep fruits inside special chambers and initiate the ripening process through administration of ethylene. Ethylene is usually administered through cylinders with inadequate control of its final concentration in the chamber. The aim of this study is the development of a new technology to accurately regulate ethylene concentration in the atmosphere where fruits are preserved: a polymeric film, containing an inclusion complex of α-cyclodextrin with ethylene, was developed. The complex was prepared by molecular encapsulation which allows the entrapment of ethylene into the cavity of α-cyclodextrin. After encapsulation, ethylene can be gradually released from the inclusion complex and its release rate can be regulated by temperature and humidity. The inclusion complex was dispersed into a thin polymeric film produced by UV-curing. This method was used because is solvent-free and involves low operating temperature; both conditions are necessary to prevent rapid release of ethylene from the film. The polymeric films were characterized with respect to thermal behaviour, crystalline structure and kinetics of ethylene release, showing that can effectively control the release of ethylene within confined volume.

  19. Effects of unexpected lateral mass placement on trunk loading in lifting

    NARCIS (Netherlands)

    van der Burg, J.C.E.; Kingma, I.; van Dieen, J.H.

    2003-01-01

    Study Design. A repeated measurements experiment of spinal loading in healthy subjects. Objectives. To test whether unexpected lateral mass placement increases low back loading and trunk movement when subjects are lifting a mass in upright posture. Summary of Background Data. Epidemiologic studies

  20. Methane Flux to the Atmosphere from the Deepwater Horizon Oil Leak

    Science.gov (United States)

    Yvon-Lewis, S. A.; Hu, L.; Kessler, J. D.; Garcia Tigreros, F.; Chan, E. W.; Du, M.

    2010-12-01

    The unfortunate blowout at the BP Deepwater Horizon (DWH) oil rig on April 20, which killed 11 people, was releasing oil and methane at an average rate of 58,000 barrels per day into the deep ocean, until it was recently capped resulting in a total of 4.9 million barrels released (National Incident Command Report, 2010). The methane component of the emission was estimated at 40-60%. As part of a NSF funded RAPID award, the sea-to-air flux of methane from the blowout at the Deepwater Horizon was measured on board the R/V Cape Hatteras from June 11-20 with substantial spatial and temporal resolution over the course of seven days in June 2010. Air and water concentrations were analyzed continuously from a flowing air line and a continuously flowing seawater equilibrator using cavity ring-down spectrometers (CRDS) and a gas chromatograph with a flame ionization detector (GC-FID). The results indicate a low flux of methane to the atmosphere (0.024 μmol m^{-2} d^{-1}) with atmospheric and seawater equilibrium mixing ratios averaging 1.86 ppm and 2.85 ppm, respectively within the survey area. Most of the methane emitted from the wellhead was not emitted to the atmosphere. It dissolved into the water column at depth.

  1. Meteorological perspective on intermediate range atmospheric dispersion

    International Nuclear Information System (INIS)

    Van der Hoven, I.

    1981-01-01

    The intermediate range of atmospheric transport and diffusion is defined as those dispersion processes which take place at downwind distances of 10 to 100 kilometers from pollutant sources. Meteorologists often define this range as the mesoscale. It is the range of distances where certain environmental assessments are of concern such as the determination of significant deterioration of visibility, the effect of effluent releases from tall stacks, and the effect of pollutant sources in rural settings upon the more distant urban centers. Atmospheric diffusion theory is based on steady state conditions and spatial homogeniety. Techniques must be developed to measure the inhomogenieties, models must be devised to account for the complexities, and a data base consisting of appropriate measured meteorological parameters concurrent with tracer gas concentrations should be collected

  2. Study of the radon released from open drill holes

    International Nuclear Information System (INIS)

    Pacer, J.C.

    1981-06-01

    The radon emanating from three open drill holes was measured at a site of known uranium mineralization in the Red Desert of south central Wyoming. The radon flux from the soil and drill holes was measured by the accumulator method with activated charcoal cartridges. The surface soil was found to release radon at an average rate of 0.41 atoms/cm 2 /sec; the radon emanating from the holes was more variable than that from the soil. The three holes studied released an average of 47 atoms/cm 2 /sec of radon. This average is equivalent to the radon released to the atmosphere by 14.5 ft 2 of soil. The data indicate that the radon emanated from an open drill hole is not as significant as other possible activities at a drill site (i.e. digging a trench or drilling a hole) or from household activities involving the usage of water

  3. Diagnosis of the Tropical Moisture Exports to the Mid-Latitudes and the Role of Atmospheric Steering in the Extreme Precipitation

    Directory of Open Access Journals (Sweden)

    Mengqian Lu

    2017-12-01

    Full Text Available Three river basins, i.e., the Yangtze river, the Mississippi river and the Loire river, were presented as case studies to explore the association among atmospheric circulations, moisture exports and extreme precipitations in the mid-latitudes. The major moisture source regions in the tropics for the three river basins are first identified using the Tropical Moisture Exports (TMEs dataset. The space-time characteristics of their respective moisture sources are presented. Then, the trajectory curve clustering analysis is applied to the TMEs tracks originating from the identified source regions during each basin’s peak TMEs activity and flood seasons. Our results show that the moisture tracks for each basin can be categorized into 3 or 4 clusters with distinct spatial trajectory features. Our further analysis on these clustered trajectories reveals that the contributions of moisture release from different clusters are associated with their trajectory features and travel speeds. In order to understand the role of associated atmospheric steering, daily composites of the geopotential heights anomalies and the vertical integral of moisture flux anomalies from 7 days ahead to the extreme precipitation days (top 5% are examined. The evolutions of the atmospheric circulation patterns and the moisture fluxes are both consistent with the TMEs tracks that contribute more moisture releases to the study regions. The findings imply that atmospheric steering plays an important role in the moisture transport and release, especially for the extreme precipitations. We also find that the association between TMEs moisture release and precipitation is nonlinear. The extreme precipitation is associated with high TMEs moisture release for all of the three study regions.

  4. Site-sensitive hazards of potential airborne radioactive release from sources on the Kola peninsula

    International Nuclear Information System (INIS)

    Bergman, R.; Thaning, L.; Baklanov, A.

    1998-02-01

    In this work we focus on cases of airborne releases from some of the sources on the Kola Peninsula - primarily nuclear reactors on submarines and the Kola Nuclear Power Plant (KNPP). The purpose of our study is to illustrate, and discuss some features - dependent on site and release characteristics - of the deposition patterns resulting from assumed unit radioactive releases to the atmosphere from a location at a fjord and from the KNPP in Polyarnye Zori. Using meteorological data for one real weather situation, the analysis is based on simulating the transport in air of assumed radioactive releases and estimating the deposition pattern on local, meso- and regional scales. By allowing unit releases to occur simultaneously from the site at the fjord and from the power plant (and with the same release profile in time) comparisons are made of differences in deposition patterns in and outside the Kola region. In this case study a set of assumed release heights, durations of the release, and particle size distributions are applied to indicate the dependence for the resulting deposition pattern on these parameters

  5. Lower incidence of unexpected in-hospital death after interprofessional implementation of a bedside track-and-trigger system

    DEFF Research Database (Denmark)

    Bunkenborg, Gitte; Samuelson, Karin Samuelsonkarin; Poulsen, Ingrid

    2014-01-01

    In-hospital patients may suffer unexpected death because of suboptimal monitoring. Early recognition of deviating physiological parameters may enable staff to prevent unexpected in-hospital death. The aim of this study was to evaluate short- and long-term effects of systematic interprofessional u...... of early warning scoring, structured observation charts, and clinical algorithms for bedside action....

  6. Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

  7. Estimation of radiological consequences from accidental iodine releases at nuclear power plants

    International Nuclear Information System (INIS)

    Drozdovitch, V.V.

    2001-01-01

    The radiological consequences of a beyond design-basis accident at an NPP for a VVER-1000 reactor are evaluated. Using the software code COSYMA and accounting for radioiodine activity release to the atmosphere at the early stage of the accident, the radionuclide concentration in air and ground deposition densities were estimated. Inhalation and ingestion thyroid doses to different population sub-groups have been calculated. Using modern knowledge about the risk of radiation-induced cancer, the radiological danger of radionuclides released is evaluated for different exposure pathways. Thyroid doses and risk was estimated for populations living at different distances from the NPP. The comparative analysis of exposure pathways and radiological danger of the radionuclides in release during early and intermediate stage of accident has conducted. (author)

  8. Effects of unexpected chords and of performer's expression on brain responses and electrodermal activity.

    Science.gov (United States)

    Koelsch, Stefan; Kilches, Simone; Steinbeis, Nikolaus; Schelinski, Stefanie

    2008-07-09

    There is lack of neuroscientific studies investigating music processing with naturalistic stimuli, and brain responses to real music are, thus, largely unknown. This study investigates event-related brain potentials (ERPs), skin conductance responses (SCRs) and heart rate (HR) elicited by unexpected chords of piano sonatas as they were originally arranged by composers, and as they were played by professional pianists. From the musical excerpts played by the pianists (with emotional expression), we also created versions without variations in tempo and loudness (without musical expression) to investigate effects of musical expression on ERPs and SCRs. Compared to expected chords, unexpected chords elicited an early right anterior negativity (ERAN, reflecting music-syntactic processing) and an N5 (reflecting processing of meaning information) in the ERPs, as well as clear changes in the SCRs (reflecting that unexpected chords also elicited emotional responses). The ERAN was not influenced by emotional expression, whereas N5 potentials elicited by chords in general (regardless of their chord function) differed between the expressive and the non-expressive condition. These results show that the neural mechanisms of music-syntactic processing operate independently of the emotional qualities of a stimulus, justifying the use of stimuli without emotional expression to investigate the cognitive processing of musical structure. Moreover, the data indicate that musical expression affects the neural mechanisms underlying the processing of musical meaning. Our data are the first to reveal influences of musical performance on ERPs and SCRs, and to show physiological responses to unexpected chords in naturalistic music.

  9. Effects of unexpected chords and of performer's expression on brain responses and electrodermal activity.

    Directory of Open Access Journals (Sweden)

    Stefan Koelsch

    Full Text Available BACKGROUND: There is lack of neuroscientific studies investigating music processing with naturalistic stimuli, and brain responses to real music are, thus, largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: This study investigates event-related brain potentials (ERPs, skin conductance responses (SCRs and heart rate (HR elicited by unexpected chords of piano sonatas as they were originally arranged by composers, and as they were played by professional pianists. From the musical excerpts played by the pianists (with emotional expression, we also created versions without variations in tempo and loudness (without musical expression to investigate effects of musical expression on ERPs and SCRs. Compared to expected chords, unexpected chords elicited an early right anterior negativity (ERAN, reflecting music-syntactic processing and an N5 (reflecting processing of meaning information in the ERPs, as well as clear changes in the SCRs (reflecting that unexpected chords also elicited emotional responses. The ERAN was not influenced by emotional expression, whereas N5 potentials elicited by chords in general (regardless of their chord function differed between the expressive and the non-expressive condition. CONCLUSIONS/SIGNIFICANCE: These results show that the neural mechanisms of music-syntactic processing operate independently of the emotional qualities of a stimulus, justifying the use of stimuli without emotional expression to investigate the cognitive processing of musical structure. Moreover, the data indicate that musical expression affects the neural mechanisms underlying the processing of musical meaning. Our data are the first to reveal influences of musical performance on ERPs and SCRs, and to show physiological responses to unexpected chords in naturalistic music.

  10. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Science.gov (United States)

    Silva, Lucas C R; Anand, Madhur; Leithead, Mark D

    2010-07-21

    The synergetic effects of recent rising atmospheric CO(2) and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  11. Results of atmospheric diffusion experiments, vol.3

    International Nuclear Information System (INIS)

    Kakuta, Michio; Hayashi, Takashi; Adachi, Takashi.

    1988-02-01

    An extensive study on 'Emergency monitoring and prediction code system' has been carried in JAERI since 1980. Six series of field experiments on atmospheric diffusion were conducted to develop and verify the prediction models for environmental concentration distribution following accidental release of radioactivity. Results of field experiments (Inland complex terrain, surface and elevated point sources) conducted in 15 - 19th October 1984 (TSUKUBA84) and in 6 - 10th November 1985 (TSUKUBA85) are contained in this volume. (author)

  12. Elemental composition of suspended particles released in refuse incineration

    International Nuclear Information System (INIS)

    Mamuro, Tetsuo; Mizohata, Akira

    1979-01-01

    Suspended particles released in refuse incineration were subjected to multielement analysis by means of instrumental neutron activation method and energy dispersive X-ray fluorescence spectrometry. The analytical results were compared with the elemental concentrations observed in the urban atmosphere, and the contribution of the refuse incineration to the urban atmosphere was roughly estimated. Greenberg et al. pointed out on the basis of their analyses that the refuse incineration can account for major portions of the Zn, Cd and Sb observed on urban aerosols. According to our results, the contribution of the refuse incineration for Zn, Cd and Sb is not negligible, but not so serious as in U.S.A. big cities. In Japan big cities there must be other more important sources of these elements. (author)

  13. Sampling and characterization of aerosols formed in the atmospheric hydrolysis of UF6

    International Nuclear Information System (INIS)

    Bostick, W.D.; McCulla, W.H.; Pickrell, P.W.; Branam, D.A.

    1983-01-01

    When gaseous UF 6 is released into the atmosphere, it rapidly reacts with ambient moisture to form an aerosol of uranyl fluoride and HF. As part of our Safety Analysis program, we have performed several experimental releases of UF 6 (from natural uranium) in contained volumes in order to investigate techniques for sampling and characterizing the aerosol materials. The aggregrate particle morphology and size distribution have been found to be dependent upon several conditions, including the relative humidity at the time of the release and the elapse time after the release. Aerosol composition and settling rate have been investigated using isokinetic samplers for the separate collection of UO 2 F 2 and HF, and via laser spectroscopic remote sensing (Mie scatter and infrared spectroscopy). 8 references

  14. Atmospheric Signature of the Agulhas Current

    Science.gov (United States)

    Nkwinkwa Njouodo, Arielle Stela; Koseki, Shunya; Keenlyside, Noel; Rouault, Mathieu

    2018-05-01

    Western boundary currents play an important role in the climate system by transporting heat poleward and releasing it to the atmosphere. While their influence on extratropical storms and oceanic rainfall is becoming appreciated, their coastal influence is less known. Using satellite and climate reanalysis data sets and a regional atmospheric model, we show that the Agulhas Current is a driver of the observed band of rainfall along the southeastern African coast and above the Agulhas Current. The Agulhas current's warm core is associated with sharp gradients in sea surface temperature and sea level pressure, a convergence of low-level winds, and a co-located band of precipitation. Correlations among wind convergence, sea level pressure, and sea surface temperature indicate that these features show high degree of similarity to those in the Gulf Stream region. Model experiments further indicate that the Agulhas Current mostly impacts convective rainfall.

  15. Situation 2002: release monitoring and surveillance of environment of Cea centers

    International Nuclear Information System (INIS)

    2003-07-01

    This publication renders an account of the situation of the releases of liquid and gaseous radioactive effluents, for the year 2002, as well as the radioactivity levels measured in the vicinity of Cea centers through the systematic surveillance of atmosphere, waters, vegetation and milk. An analysis on five years allows to follow their evolution. (N.C.)

  16. Fournier gangrene and unexpected death.

    Science.gov (United States)

    Bury, Danielle; Byard, Roger W

    2012-11-01

    Fournier gangrene represents a rare but progressive perineal infection that may result in rapid death. A 70-year-old man with poorly controlled diabetes mellitus and alcohol abuse is reported who was found unexpectedly dead. He had last been contacted the night before his death. At autopsy, the most striking finding was deep necrotic ulceration of the scrotum with exposure of underlying deep muscles and testicles, with blood cultures positive for Escherichia coli. Death was, therefore, attributed to necrotic ulceration/gangrene of the perineum (Fournier gangrene) that was due to E. coli sepsis with underlying contributing factors of diabetes mellitus and alcoholism. In addition there was morbid obesity (body mass index 46.9), cirrhosis of the liver, and marked focal coronary artery atherosclerosis with significant cardiomegaly. Fournier gangrene may be an extremely aggressive condition that can result in rapid death, as was demonstrated by the rapid progression in the reported case. © 2012 American Academy of Forensic Sciences.

  17. Comparison of the local-scale atmospheric dispersion model Cedrat with 85KR measurements

    International Nuclear Information System (INIS)

    Rennesson, M.; Devin, P.; Maro, D.; Fitamant, M.L.; Bouland, P.

    2004-01-01

    An accurate model of atmospheric dispersion of radionuclides over the complex terrain of the La Hague reprocessing plant (North Cotentin, France) has been developed by COGEMA, in partnership with Paris VI University. This model, called CEDRAT 1.0.1 (operational since October 2002), takes into account areas typically outside the validity limits of Gaussian models: relief and building influence, short-distance (beyond 500 m from the release point) and stable atmospheric conditions. The modelling tool is based on an original method: a 2D-meshed model for flow resolution at permanent rate in the prevailing wind direction, and a 3D description of the dispersion phenomena, taking into account wet and dry deposits, at permanent or transitory rate. This leads to an effective compromise between rapidity (45 min on a 6000 nodes grid, with a standard PC), robustness and accuracy, coupled with a user-friendly interface. Primarily the validation process consisted of a comparison with the 3D complex dispersion reference model MERCURE, developed by EDF. Then, MERCURE and CEDRAT results were compared on real release scenario basis, for which actual meteorological conditions and tracer data collected at monitoring stations around the site were known. To enlarge this validation process, a second level of comparison was made in collaboration with a IRSN Cherbourg team, through different field experiments, which provided both ground and elevated level measurements (collected with a captive balloon), for different stability classes of the atmosphere. The plume tracer is krypton 85, an inert gas released from a height of 100 m. Thus, the aim of this paper is to present the original method to describe short distance dispersion over complex terrain and its validation enrichment for stability conditions and areas not yet observed, through wind and cross-wind Atmospheric Transfer Coefficients comparisons, at both ground and elevated levels. (author)

  18. Building shielding effects on radiation doses from routine radionuclide releases

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1977-01-01

    In calculating population doses from the release of radionuclides to the atmosphere, it is usually assumed that man spends all of his time outdoors standing on a smooth infinite plane. Realistically, however, man spends most of the time indoors, so that substantial reductions in radiation doses may result compared with the usual estimates. Calculational models were developed to study the effects of building structures on radiation doses from routine releases of radionuclides to the atmosphere. Both internal dose from inhaled radionuclides and external photon dose from airborne and surface-deposited radionuclides are considered. The effect of building structures is described quantitatively by a dose reduction factor, which is the ratio of the dose inside a structure to the corresponding dose with no structure present. The internal dose from inhaled radionuclides is proportional to the radionuclide concentration in the air. Assuming that the outdoor airborne concentration is constant with time, the time-dependence of the indoor airborne concentration in terms of the structure air ventilation rate, the deposition velocities for radionuclides on the inside floor, walls, and ceiling, and the radioactive decay constant, were calculated

  19. Next of kin’s experiences of sudden and unexpected death from stroke - a study of narratives

    Science.gov (United States)

    2013-01-01

    Background Death always evokes feelings in those close to the afflicted person. When death comes suddenly the time for preparation is minimal and the next of kin have to cope with the situation despite their own sorrow. The suddenness is found to be stressful for the next of kin and communication both with healthcare professionals and information about what has happened has been found helpful. The aim of this study was to illuminate the experiences of next of kin from the sudden and unexpected death of a relative from acute stroke. Methods Data was collected over a 12-month period in 2009–2010. Twelve next of kin of patients cared for in stroke units who died suddenly and unexpectedly from stroke were interviewed using a narrative method. The narratives were analyzed using narrative thematic analysis. Results Three themes emerged showing facets of next of kin’s experiences of a relative’s sudden and unexpected death from stroke: Divided feelings about the sudden and unexpected death; Perception of time and directed attention when keeping vigil; Contradictions and arbitrary memories when searching for understanding. Conclusions To have to live in the aftermath of severe stroke is absolute horror in people’s imagination and death is seen as the lesser of two evils. The sudden and unexpected death totally pervades the next of kin’s life, directs their attention to the dying person and even causes them to forget themselves and their own needs, and leads to difficulties in information intake. It is a challenge for the healthcare professionals to be able to identify the individual needs of the next of kin in this situation. PMID:23590246

  20. The ionization mechanisms in direct and dopant-assisted atmospheric pressure photoionization and atmospheric pressure laser ionization.

    Science.gov (United States)

    Kauppila, Tiina J; Kersten, Hendrik; Benter, Thorsten

    2014-11-01

    A novel, gas-tight API interface for gas chromatography-mass spectrometry was used to study the ionization mechanism in direct and dopant-assisted atmospheric pressure photoionization (APPI) and atmospheric pressure laser ionization (APLI). Eight analytes (ethylbenzene, bromobenzene, naphthalene, anthracene, benzaldehyde, pyridine, quinolone, and acridine) with varying ionization energies (IEs) and proton affinities (PAs), and four common APPI dopants (toluene, acetone, anisole, and chlorobenzene) were chosen. All the studied compounds were ionized by direct APPI, forming mainly molecular ions. Addition of dopants suppressed the signal of the analytes with IEs above the IE of the dopant. For compounds with suitable IEs or Pas, the dopants increased the ionization efficiency as the analytes could be ionized through dopant-mediated gas-phase reactions, such as charge exchange, proton transfer, and other rather unexpected reactions, such as formation of [M + 77](+) in the presence of chlorobenzene. Experiments with deuterated toluene as the dopant verified that in case of proton transfer, the proton originated from the dopant instead of proton-bound solvent clusters, as in conventional open or non-tight APPI sources. In direct APLI using a 266 nm laser, a narrower range of compounds was ionized than in direct APPI, because of exceedingly high IEs or unfavorable two-photon absorption cross-sections. Introduction of dopants in the APLI system changed the ionization mechanism to similar dopant-mediated gas-phase reactions with the dopant as in APPI, which produced mainly ions of the same form as in APPI, and ionized a wider range of analytes than direct APLI.