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Sample records for accident consequence model

  1. Chernobyl accident and its consequences

    Energy Technology Data Exchange (ETDEWEB)

    Gittus, J.H.

    1987-06-01

    The paper concerns the Chernobyl reactor accident, with emphasis on the design of the RBMK reactor and nuclear safety. A description is given of the Chernobyl nuclear power plant, including details of the RMBK reactor and safety systems. Comments on the design of the RBMK by UK experts prior to the accident are summarized, along with post-accident design changes to improve RBMK safety. Events of the Chernobyl accident are described, as well as design deficiencies highlighted by the accident. Differences between the USSR and UK approaches to nuclear safety are commented on. Finally source terms, release periods and environmental consequences are briefly discussed.

  2. Chernobyl accident and its consequences

    Energy Technology Data Exchange (ETDEWEB)

    Gittus, J.H.; Bonell, P.G.; Hicks, D.

    1987-01-01

    The USSR power reactor programme is first described. The reasons for the accident at the Chernobyl-4 RBMK nuclear reactor on 26 April 1986, the sequence of events that took place, and the immediate and long-term consequences are considered. A description of the RBMK-type reactors is given and the design changes resulting from the experience of the accident are explained. The source terms describing the details of the radioactivity release associated with the accident and the environmental consequences are covered in the last two sections of the report. Throughout the text comments referring to the UK Nuclear Installations Inspectorate Safety assessment principles have been inserted. (U.K.).

  3. Health effects models for off-site radiological consequence analysis on nuclear reactor accidents (II)

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Toshimitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Takahashi, Tomoyuki [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Yonehara, Hidenori [National Inst. of Radiological Sciences, Chiba (Japan)] [eds.

    2000-12-01

    This report is a revision of JAERI-M 91-005, 'Health Effects Models for Off-Site Radiological Consequence Analysis of Nuclear Reactor Accidents'. This revision provides a review of two revisions of NUREG/CR-4214 reports by the U.S. Nuclear Regulatory Commission which is the basis of the JAERI health effects models and other several recent reports that may impact the health effects models by international organizations. The major changes to the first version of the JAERI health effects models and the recommended parameters in this report are for late somatic effects. These changes reflect recent changes in cancer risk factors that have come from longer followup and revised dosimetry in major studies on the Japanese A-bomb survivors. This report also provides suggestions about future revisions of computational aspects on health effects models. (author)

  4. Review of methodology for accident consequence assessment

    Energy Technology Data Exchange (ETDEWEB)

    Strenge, D.L.; Soldat, J.K.; Watson, E.C.

    1978-09-01

    This report reviews current methodologies for reactor accident consequence analysis and describes areas where modifications are warranted. Methodologies reviewed are: (1) Models in Regulatory Guides 1.109, 1.111 and 1.113 used for evaluation of compliance with 10 CFR 50 Appendix I; (2) Models in Regulatory Guides used for evaluation of consequences from accidents of Classes 3-8; (3) Models for evaluation of Class 9 accidents presented in the Reactor Safety Study; and (4) Models in the Liquid Pathway Generic Study. The review is designed to aid in the ultimate goal of selection of a comprehensive set of models to extend the Class 9 methodology of the Reactor Safety Study to the analysis of Classes 3-8 accidents.

  5. A dynamic food-chain model and program for predicting the consequences of nuclear accident

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A dynamic food-chain model and program, DYFOM-95, forpredicting the radiological consequences of nuclear accident hasbeen developed, which is not only suitable to the West food-chainbut also to Chinese food chain. The following processes, caused byaccident release which will make an impact on radionuclideconcentration in the edible parts of vegetable are considered: dryand wet deposition interception and initial retention,translocation, percolation, root uptake and tillage. Activityintake rate of animals, effects of processing and activity intakeof human through ingestion pathway are also considered incalculations. The effects of leaf area index LAI of vegetable areconsidered in dry deposition model. A method for calculating thecontribution of rain with different period and different intensityto total wet deposition is established. The program contains 1 maincode and 5 sub-codes to calculate dry and wet deposition on surfaceof vegetable and soil, translocation of nuclides in vegetable,nuclide concentration in the edible parts of vegetable and inanimal products and activity intake of human and so on.

  6. The consequences of Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Ion Chioșilă

    2016-12-01

    Full Text Available These days marks 30 years since the Chernobyl nuclear accident, followed by massive radioactive contamination of the environment and human in Belarus, Ukraine and Russia, and resulted in many deaths among people who intervened to decrease the effects of the nuclear disaster. The 26 April 1986 nuclear accident contaminated all European countries, but at a much lower level, without highlighted consequences on human health. In special laboratories, the main radionuclides (I-131, Cs-137, Cs-134 and Sr-90 were also analyzed in Romania from environmental samples, food, even human subjects. These radionuclides caused the population to receive a low dose of about 1 mSv in 1986 that is half of the dose of the natural background radiation (2.4 mSv per year. As in all European countries (excluding Ukraine, Belarus and Russia this dose of about 1 mSv fell rapidly by 1990, reaching levels close to ones before the accident at the nuclear tests.

  7. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.S. (Harvard Univ., Boston, MA (USA). School of Public Health)

    1990-01-01

    This report describes dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes -- are considered. In addition, models are included for assessing the risks of several nonlethal early and continuing effects -- including prodromal vomiting and diarrhea, hypothyroidism and radiation thyroiditis, skin burns, reproductive effects, and pregnancy losses. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid, and other.'' The category, other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also developed. For most cancers, both incidence and mortality are addressed. The models of cancer risk are derived largely from information summarized in BEIR III -- with some adjustment to reflect more recent studies. 64 refs., 18 figs., 46 tabs.

  8. Consequences of severe nuclear accidents in Europe

    Science.gov (United States)

    Seibert, Petra; Arnold, Delia; Mraz, Gabriele; Arnold, Nikolaus; Gufler, Klaus; Kromp-Kolb, Helga; Kromp, Wolfgang; Sutter, Philipp

    2013-04-01

    A first part of the presentation is devoted to the consequences of the severe accident in the 1986 Chernobyl NPP. It lead to a substantial radioactive contaminated of large parts of Europe and thus raised the awareness for off-site nuclear accident consequences. Spatial patterns of the (transient) contamination of the air and (persistent) contamination of the ground were studied by both measurements and model simulations. For a variety of reasons, ground contamination measurements have variability at a range of spatial scales. Results will be reviewed and discussed. Model simulations, including inverse modelling, have shown that the standard source term as defined in the ATMES study (1990) needs to be updated. Sensitive measurements of airborne activities still reveal the presence of low levels of airborne radiocaesium over the northern hemisphere which stems from resuspension. Over time scales of months and years, the distribution of radionuclides in the Earth system is constantly changing, for example relocated within plants, between plants and soil, in the soil, and into water bodies. Motivated by the permanent risk of transboundary impacts from potential major nuclear accidents, the multidisciplinary project flexRISK (see http://flexRISK.boku.ac.at) has been carried out from 2009 to 2012 in Austria to quantify such risks and hazards. An overview of methods and results of flexRISK is given as a second part of the presentation. For each of the 228 NPPs, severe accidents were identified together with relevant inventories, release fractions, and release frequencies. Then, Europe-wide dispersion and dose calculations were performed for 2788 cases, using the Lagrangian particle model FLEXPART. Maps of single-case results as well as various aggregated risk parameters were produced. It was found that substantial consequences (intervention measures) are possible for distances up to 500-1000 km, and occur more frequently for a distance range up to 100-300 km, which is in

  9. Medical consequences of Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Galstyan I.A.

    2015-12-01

    Full Text Available Aim: to study the long-term effects of acute radiation syndrome (ARS, developed at the victims of the Chernobyl accident. Material and Methods. 237 people were exposed during the accident, 134 of them were diagnosed with ARS. Dynamic observation implies a thorough annual examination in a hospital. Results. In the first 1.5-2 years after the ARS mean group indices of peripheral blood have returned to normal. However, many patients had transient expressed moderate cytopenias. Granulocytopenia, thrombocytopenia, lymphopenia and erythropenia were the most frequently observed things during the first 5 years after the accident. After 5 years their occurences lowered. In 11 patients the radiation cataract was detected. A threshold dose for its development is a dose of 3.2 Gy Long-term effects of local radiation lesions (LRL range from mild skin figure smoothing to a distinct fibrous scarring, contractures, persistently recurrent late radiation ulcers. During all years of observation we found 8 solid tumors, including 2 thyroid cancers. 5 hematologic diseases were found. During 29 years 26 ARS survivors died of various causes. Conclusion. The health of ones with long-term ARS effects is determined by the evolution of the LRL effects on skin, radiation cataracts, hema-tological diseases and the accession of of various somatic diseases, not caused by radiation.

  10. Health effects models for nuclear power plant accident consequence analysis. Part 1, Introduction, integration, and summary: Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.S. [Harvard School of Public Health, Boston, MA (United States); Abrahmson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Inhalation Toxicology Research Inst., Albuquerque, NM (United States); Gilbert, E.S. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1993-10-01

    This report is a revision of NUREG/CR-4214, Rev. 1, Part 1 (1990), Health Effects Models for Nuclear Power Plant Accident Consequence Analysis. This revision has been made to incorporate changes to the Health Effects Models recommended in two addenda to the NUREG/CR-4214, Rev. 1, Part 11, 1989 report. The first of these addenda provided recommended changes to the health effects models for low-LET radiations based on recent reports from UNSCEAR, ICRP and NAS/NRC (BEIR V). The second addendum presented changes needed to incorporate alpha-emitting radionuclides into the accident exposure source term. As in the earlier version of this report, models are provided for early and continuing effects, cancers and thyroid nodules, and genetic effects. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes are considered. Linear and linear-quadratic models are recommended for estimating the risks of seven types of cancer in adults - leukemia, bone, lung, breast, gastrointestinal, thyroid, and ``other``. For most cancers, both incidence and mortality are addressed. Five classes of genetic diseases -- dominant, x-linked, aneuploidy, unbalanced translocations, and multifactorial diseases are also considered. Data are provided that should enable analysts to consider the timing and severity of each type of health risk.

  11. Health effects model for nuclear power plant accident consequence analysis. Part I. Introduction, integration, and summary. Part II. Scientific basis for health effects models

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.S.; Moeller, D.W.; Cooper, D.W.

    1985-07-01

    Analysis of the radiological health effects of nuclear power plant accidents requires models for predicting early health effects, cancers and benign thyroid nodules, and genetic effects. Since the publication of the Reactor Safety Study, additional information on radiological health effects has become available. This report summarizes the efforts of a program designed to provide revised health effects models for nuclear power plant accident consequence modeling. The new models for early effects address four causes of mortality and nine categories of morbidity. The models for early effects are based upon two parameter Weibull functions. They permit evaluation of the influence of dose protraction and address the issue of variation in radiosensitivity among the population. The piecewise-linear dose-response models used in the Reactor Safety Study to predict cancers and thyroid nodules have been replaced by linear and linear-quadratic models. The new models reflect the most recently reported results of the follow-up of the survivors of the bombings of Hiroshima and Nagasaki and permit analysis of both morbidity and mortality. The new models for genetic effects allow prediction of genetic risks in each of the first five generations after an accident and include information on the relative severity of various classes of genetic effects. The uncertainty in modeloling radiological health risks is addressed by providing central, upper, and lower estimates of risks. An approach is outlined for summarizing the health consequences of nuclear power plant accidents. 298 refs., 9 figs., 49 tabs.

  12. The Chernobyl accident consequences; Consequences de l'accident de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    Five teen years later, Tchernobyl remains the symbol of the greater industrial nuclear accident. To take stock on this accident, this paper proposes a chronology of the events and presents the opinion of many international and national organizations. It provides also web sites references concerning the environmental and sanitary consequences of the Tchernobyl accident, the economic actions and propositions for the nuclear safety improvement in the East Europe. (A.L.B.)

  13. Model review and evaluation for application in DOE safety basis documentation of chemical accidents - modeling guidance for atmospheric dispersion and consequence assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Woodarad, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Hanna, S. R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hesse, D. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Huang, J. -C. [Argonne National Lab. (ANL), Argonne, IL (United States); Lewis, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Mazzola, C. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    1997-09-01

    The U.S. Department of Energy (DOE), through its Defense Programs (DP), Office of Engineering and Operations Suppon, established the Accident Phenomenology and Consequence (AP AC) Methodology Evaluation Program to identify and evaluate methodologies and computer codes to support accident phenomenological and consequence calculations for both radiological and nonradiological materials at DOE facilities and to identify development needs. The program is also intended to define and recommend "best or good engineering/safety analysis practices" to be followed in preparing ''design or beyond design basis" assessments to be included in DOE nuclear and nonnuclear facility safety documents. The AP AC effort is intended to provide scientifically sound and more consistent analytical approaches, by identifying model selection procedures and application methodologies, in order to enhance safety analysis activities throughout the DOE complex.

  14. Reconsidering Health Consequences of the Chernobyl Accident.

    Science.gov (United States)

    Socol, Yehoshua

    2015-01-01

    The Chernobyl accident led to major human suffering caused by the evacuation and other counter-measures. However, the direct health consequences of the accident-related radiation exposures, besides the acute effects and small number of thyroid cancers, have not been observed. This absence is challenged by some influential groups affecting public policies who claim that the true extent of radiogenic health consequences is covered up. We consider such claims. The most conservative (in this case - overestimating) linear no-threshold hypothesis was used to calculate excess cancer expectations for cleanup workers, the population of the contaminated areas and the global population. Statistical estimations were performed to verify whether such expected excess was detectable. The calculated cancer excess for each group is much less than uncertainties in number of cancer cases in epidemiological studies. Therefore the absence of detected radiation carcinogenesis is in full correspondence with the most conservative a priori expectations. Regarding the cover-up claims, rational choice analysis was performed. Such analysis shows that these claims are ill-founded. The present overcautious attitude to radiological hazards should be corrected in order to mitigate the present suffering and to avoid such suffering in the future.

  15. Review of the chronic exposure pathways models in MACCS (MELCOR Accident Consequence Code System) and several other well-known probabilistic risk assessment models

    Energy Technology Data Exchange (ETDEWEB)

    Tveten, U. (Institutt for Energiteknikk, Kjeller (Norway))

    1990-06-01

    The purpose of this report is to document the results of the work performed by the author in connection with the following task, performed for US Nuclear Regulatory Commission, (USNRC) Office of Nuclear Regulatory Research, Division of Systems Research: MACCS Chronic Exposure Pathway Models: Review the chronic exposure pathway models implemented in the MELCOR Accident Consequence Code System (MACCS) and compare those models to the chronic exposure pathway models implemented in similar codes developed in countries that are members of the OECD. The chronic exposures concerned are via: the terrestrial food pathways, the water pathways, the long-term groundshine pathway, and the inhalation of resuspended radionuclides pathway. The USNRC has indicated during discussions of the task that the major effort should be spent on the terrestrial food pathways. There is one chapter for each of the categories of chronic exposure pathways listed above.

  16. MELCOR Accident Consequence Code System (MACCS)

    Energy Technology Data Exchange (ETDEWEB)

    Jow, H.N.; Sprung, J.L.; Ritchie, L.T. (Sandia National Labs., Albuquerque, NM (USA)); Rollstin, J.A. (GRAM, Inc., Albuquerque, NM (USA)); Chanin, D.I. (Technadyne Engineering Consultants, Inc., Albuquerque, NM (USA))

    1990-02-01

    This report describes the MACCS computer code. The purpose of this code is to simulate the impact of severe accidents at nuclear power plants on the surrounding environment. MACCS has been developed for the US Nuclear Regulatory Commission to replace the previously used CRAC2 code, and it incorporates many improvements in modeling flexibility in comparison to CRAC2. The principal phenomena considered in MACCS are atmospheric transport, mitigative actions based on dose projection, dose accumulation by a number of pathways including food and water ingestion, early and latent health effects, and economic costs. The MACCS code can be used for a variety of applications. These include (1) probabilistic risk assessment (PRA) of nuclear power plants and other nuclear facilities, (2) sensitivity studies to gain a better understanding of the parameters important to PRA, and (3) cost-benefit analysis. This report is composed of three volumes. Volume I, the User's Guide, describes the input data requirements of the MACCS code and provides directions for its use as illustrated by three sample problems. Volume II, the Model Description, describes the underlying models that are implemented in the code, and Volume III, the Programmer's Reference Manual, describes the code's structure and database management. 59 refs., 14 figs., 15 tabs.

  17. MELCOR Accident Consequence Code System (MACCS)

    Energy Technology Data Exchange (ETDEWEB)

    Rollstin, J.A. (GRAM, Inc., Albuquerque, NM (USA)); Chanin, D.I. (Technadyne Engineering Consultants, Inc., Albuquerque, NM (USA)); Jow, H.N. (Sandia National Labs., Albuquerque, NM (USA))

    1990-02-01

    This report describes the MACCS computer code. The purpose of this code is to simulate the impact of severe accidents at nuclear power plants on the surrounding environment. MACCS has been developed for the US Nuclear Regulatory Commission to replace the previously used CRAC2 code, and it incorporates many improvements in modeling flexibility in comparison to CRAC2. The principal phenomena considered in MACCS are atmospheric transport, mitigative actions based on dose projections, dose accumulation by a number of pathways including food and water ingestion, early and latent health effects, and economic costs. The MACCS code can be used for a variety of applications. These include (1) probabilistic risk assessment (PRA) of nuclear power plants and other nuclear facilities, (2) sensitivity studies to gain a better understanding of the parameters important to PRA, and (3) cost-benefit analysis. This report is composed of three volumes. Volume I, the User's Guide, describes the input data requirements of the MACCS code and provides directions for its use as illustrated by three sample problems. Volume II, the Model Description, describes the underlying models that are implemented in the code, and Volume III, the Programmer's Reference Manual, describes the code's structure and database management.

  18. MELCOR Accident Consequence Code System (MACCS)

    Energy Technology Data Exchange (ETDEWEB)

    Chanin, D.I. (Technadyne Engineering Consultants, Inc., Albuquerque, NM (USA)); Sprung, J.L.; Ritchie, L.T.; Jow, Hong-Nian (Sandia National Labs., Albuquerque, NM (USA))

    1990-02-01

    This report describes the MACCS computer code. The purpose of this code is to simulate the impact of severe accidents at nuclear power plants on the surrounding environment. MACCS has been developed for the US Nuclear Regulatory Commission to replace the previous CRAC2 code, and it incorporates many improvements in modeling flexibility in comparison to CRAC2. The principal phenomena considered in MACCS are atmospheric transport, mitigative actions based on dose projection, dose accumulation by a number of pathways including food and water ingestion, early and latent health effects, and economic costs. The MACCS code can be used for a variety of applications. These include (1) probabilistic risk assessment (PRA) of nuclear power plants and other nuclear facilities, (2) sensitivity studies to gain a better understanding of the parameters important to PRA, and (3) cost-benefit analysis. This report is composed of three volumes. This document, Volume 1, the Users's Guide, describes the input data requirements of the MACCS code and provides directions for its use as illustrated by three sample problems.

  19. Assessment of risk, damage and severity of consequences of accident into storage for LPG

    Science.gov (United States)

    Tzenova, Zlatina

    2016-12-01

    In this work an accident scenario in store for LPG is considered and consequences - forming a toxic cloud of vapor, fire and blast are modeled through models built into the software product ALOHA. The risk assessment of contamination with certain concentration is done, provided that it is an accident. Definitions for model mixture and risk assessment using geometric probability are introduced.

  20. [The Fukushima nuclear accident: consequences for Japan and for us].

    Science.gov (United States)

    Grosche, B

    2013-04-01

    The Fukushima accident was the consequence of a preceding 2-fold natural catastrophe: the earth quake of 11 March 2011 and the subsequent tsunami. Due to favourable winds and to evacuation measures the radiation exposure to the general population in Japan as a whole and with some exceptions in the region outside the evacuation zone, too, was low. In this article the attempt is made to give an estimate of health consequences to the public. This is based upon WHO's dose estimates, knowledge of the consequences of the Chernobyl accident, of the atmospheric nuclear bomb testing in Kazakhstan and on the risk of childhood leukaemia after low dose radiation exposure. For Germany, there was no radiation threat due to the accident. Nonetheless, the events in Japan made clear that the rules and standards that were developed for the case of a reactor accident need to be revised.

  1. Consequences of Windscale accident (October 1957) and study of the validity of the Sutton's mathematical model of atmospheric diffusion (1960); Etude des consequences de l'accident de Windscale (Octobre 1957) et de la validite du modele mathematique de diffusion atmospherique de Sutton (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Doury, A. [Commissariat a l' Energie Atomique (S.C.R.G.R.) Saclay (France).Centre d' Etudes Nucleaires; Martin, J.J. [Electricite de France (EDF)(S.L.P.R.), 37 - Chinon (France)

    1960-07-01

    The reactor accident that happens at the number 1 pile of Windscale in 1957 was followed by a discharge of radioactive products into the atmosphere from the 1.X.1957 at 4.30 PM to the 12.X.1957 at 3.10 PM. On october the 11{sup th} it was possible to say that there was no more risk either of external irradiation or inhalation. But in adopting a M.A.C. of 0,1 {mu}curie of iodine 131 per litre of milk, the Authority had to control the milk delivery till november 23{sup rd} on a 500 km{sup 2} area. On the other hand, this exceptional accident permit to verify that Sutton's atmospheric diffusion model could give an easy means to foresee, with a sufficient approximation, the consequences of a dispersion of radioactive products into the atmosphere. (author) [French] L'accident survenu a la pile numero 1 de Windscale en 1957 a entraine l'emission de matieres radioactives dans l'atmosphere du 10 octobre a 16h30 au 12 octobre a 15h10. Le 11 octobre, on pouvait dire qu'il n'y avait plus de risque d'irradiation externe ni de danger par inhalation. Mais en adoptant une C.M.A. de 0,1 {mu}curie d'iode 131 par litre de lait, les autorites ont du reglementer la consommation du lait jusqu'au 23 novembre sur une etendue d'environ 500 km{sup 2}. D'autre part, cet accident exceptionnel a permis de verifier que le modele de diffusion atmospherique de Sutton pouvait fournir un moyen commode de prevoir avec une approximation suffisante les consequences d'une dispersion de produits radioactifs dans l'atmosphere. (auteur)

  2. First international workshop on severe accidents and their consequences. [Chernobyl Accident

    Energy Technology Data Exchange (ETDEWEB)

    1989-07-01

    An international workshop on past severe nuclear accidents and their consequences was held in Dagomys region of Sochi, USSR on October 30--November 3, 1989. The plan of this meeting was approved by the USSR Academy of Sciences and by the USSR State Committee of the Utilization of Atomic Energy. The meeting was held under the umbrella of the ANS-SNS agreement of cooperation. Topics covered include analysis of the Chernobyl accident, safety measures for RBMK type reactors and consequences of the Chernobyl accident including analysis of the ecological, genetic and psycho-social factors. Separate reports are processed separately for the data bases. (CBS)

  3. Offsite Radiological Consequence Analysis for the Bounding Flammable Gas Accident

    CERN Document Server

    Carro, C A

    2003-01-01

    This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a single-shell tank The calculation applies reasonably conservation input parameters in accordance with DOE-STD-3009, Appendix A, guidance. Revision 1 incorporates comments received from Office of River Protection.

  4. Radiological Consequence Analyses Following a Hypothetical Severe Accident in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Juyub; Kim, Juyoul [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    In order to reflect the lessons learned from the Fukushima Daiichi nuclear power plant accident, a simulator which is named NANAS (Northeast Asia Nuclear Accident Simulator) for overseas nuclear accident has been developed. It is composed of three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. For the source-term estimation module, the representative reactor types were selected as CPR1000, BWR5 and BWR6 for China, Japan and Taiwan, respectively. Considering the design characteristics of each reactor type, the source-term estimation module simulates the transient of design basis accident and severe accident. The atmospheric dispersion prediction module analyzes the transport and dispersion of radioactive materials and prints out the air and ground concentration. Using the concentration result, the dose assessment module calculates effective dose and thyroid dose in the Korean Peninsula region. In this study, a hypothetical severe accident in Japan was simulated to demonstrate the function of NANAS. As a result, the radiological consequence to Korea was estimated from the accident. PC-based nuclear accident simulator, NANAS, has been developed. NANAS contains three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. The source-term estimation module simulates a nuclear accident for the representative reactor types in China, Japan and Taiwan. Since the maximum calculation speed is 16 times than real time, it is possible to estimate the source-term release swiftly in case of the emergency. The atmospheric dispersion prediction module analyzes the transport and dispersion of radioactive materials in wide range including the Northeast Asia. Final results of the dose assessment module are a map projection and time chart of effective dose and thyroid dose. A hypothetical accident in Japan was simulated by NANAS. The radioactive materials were released during the first 24 hours and the source

  5. Hanford Waste Tank Bump Accident and Consequence Analysis

    Energy Technology Data Exchange (ETDEWEB)

    BRATZEL, D.R.

    2000-06-20

    This report provides a new evaluation of the Hanford tank bump accident analysis and consequences for incorporation into the Authorization Basis. The analysis scope is for the safe storage of waste in its current configuration in single-shell and double-shell tanks.

  6. Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.; Gilbert, E.S. [Pacific Northwest Lab., Richland, WA (United States)

    1993-05-01

    The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

  7. Radioecological and dosimetric consequences of the Chernobyl accident in France; Consequences radioecologiques et dosimetriques de l'accident de Tchernobyl en France

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, Ph.; Beaugelin, K.; Maubert, H.; Ledenvic, Ph. [Inst. de Protection et de Surete Nucleaire, CEA Centre d' Etudes de Fontenay-aux-Roses, 92 (France)

    1997-11-01

    This study has as objective a survey of the radioecological and dosimetric consequences of the Chernobyl accident in France, as well as a prognosis for the years to come. It was requested by the Direction of Nuclear Installation Safety (DSIN) in relation to different organisms which effected measurements after this accident. It is based on the use of combined results of measurements and modelling by means of the code ASTRAL developed at IPSN. Various measurements obtained from five authorities and institutions, were made available, such as: activity of air and water, soil, processed food, agricultural and natural products. However, to achieve the survey still a modelling is needed. ASTRAL is a code for evaluating the ecological consequences of an accident. It allows establishing the correspondence between the soil Remnant Surface Activities (RSA, in Bq.m{sup -2}), the activity concentration of the agricultural production and the individual and collective doses resulting from external and internal exposures (due to inhalation and ingestion of contaminated nurture). The results of principal synthesis documents on the Chernobyl accident and its consequences were also used. The report is structured in nine sections, as follows: 1.Introduction; 2.Objective and methodology; 3.Characterization of radioactive depositions; 4;Remnant surface activities; 5.Contamination of agricultural products and foods; 6.Contamination of natural, semi-natural products and of drinking water; 7.Dosimetric evaluations; 8.Proposals for the environmental surveillance; 9.Conclusion. Finally, after ten years, one concludes that at presentthe dosimetric consequences of the Chernobyl accident in France were rather limited. For the period 1986-2046 the average individual effective dose estimated for the most struck zone is lower than 1500 {mu}Sv, which represents almost 1% of the average natural exposure for the same period. At present, the cesium 137 levels are at often inferior to those recorded

  8. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation: Part 2, Scientific bases for health effects models

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamson, S.; Bender, M.; Book, S.; Buncher, C.; Denniston, C.; Gilbert, E.; Hahn, F.; Hertzberg, V.; Maxon, H.; Scott, B.

    1989-05-01

    This report provides dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Two-parameter Weibull hazard functions are recommended for estimating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary and gastrointestinal syndromes -- are considered. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid and ''other''. The category, ''other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also provided. For most cancers, both incidence and mortality are addressed. Linear and linear-quadratic models are also recommended for assessing genetic risks. Five classes of genetic disease -- dominant, x-linked, aneuploidy, unbalanced translocation and multifactorial diseases --are considered. In addition, the impact of radiation-induced genetic damage on the incidence of peri-implantation embryo losses is discussed. The uncertainty in modeling radiological health risks is addressed by providing central, upper, and lower estimates of all model parameters. Data are provided which should enable analysts to consider the timing and severity of each type of health risk. 22 refs., 14 figs., 51 tabs.

  9. Key Characteristics of Combined Accident including TLOFW accident for PSA Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Gyung; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Yoon, Ho Joon [Khalifa University of Science, Technology and Research, Abu Dhabi (United Arab Emirates)

    2015-05-15

    The conventional PSA techniques cannot adequately evaluate all events. The conventional PSA models usually focus on single internal events such as DBAs, the external hazards such as fire, seismic. However, the Fukushima accident of Japan in 2011 reveals that very rare event is necessary to be considered in the PSA model to prevent the radioactive release to environment caused by poor treatment based on lack of the information, and to improve the emergency operation procedure. Especially, the results from PSA can be used to decision making for regulators. Moreover, designers can consider the weakness of plant safety based on the quantified results and understand accident sequence based on human actions and system availability. This study is for PSA modeling of combined accidents including total loss of feedwater (TLOFW) accident. The TLOFW accident is a representative accident involving the failure of cooling through secondary side. If the amount of heat transfer is not enough due to the failure of secondary side, the heat will be accumulated to the primary side by continuous core decay heat. Transients with loss of feedwater include total loss of feedwater accident, loss of condenser vacuum accident, and closure of all MSIVs. When residual heat removal by the secondary side is terminated, the safety injection into the RCS with direct primary depressurization would provide alternative heat removal. This operation is called feed and bleed (F and B) operation. Combined accidents including TLOFW accident are very rare event and partially considered in conventional PSA model. Since the necessity of F and B operation is related to plant conditions, the PSA modeling for combined accidents including TLOFW accident is necessary to identify the design and operational vulnerabilities.The PSA is significant to assess the risk of NPPs, and to identify the design and operational vulnerabilities. Even though the combined accident is very rare event, the consequence of combined

  10. Study on the code system for the off-site consequences assessment of severe nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

    The importance of severe nuclear accidents and probabilistic safety assessment (PSA) were brought to international attention with the occurrence of severe nuclear accidents caused by the extreme natural disaster at Fukushima Daiichi nuclear power plant in Japan. In Korea, studies on level 3 PSA had made little progress until recently. The code systems of level 3 PSA, MACCS2 (MELCORE Accident Consequence Code System 2, US), COSYMA (COde SYstem from MAria, EU) and OSCAAR (Off-Site Consequence Analysis code for Atmospheric Releases in reactor accidents, JAPAN), were reviewed in this study, and the disadvantages and limitations of MACCS2 were also analyzed. Experts from Korea and abroad pointed out that the limitations of MACCS2 include the following: MACCS2 cannot simulate multi-unit accidents/release from spent fuel pools, and its atmospheric dispersion is based on a simple Gaussian plume model. Some of these limitations have been improved in the updated versions of MACCS2. The absence of a marine and aquatic dispersion model and the limited simulating range of food-chain and economic models are also important aspects that need to be improved. This paper is expected to be utilized as basic research material for developing a Korean code system for assessing off-site consequences of severe nuclear accidents.

  11. Nuclear Accidents: Consequences for Human, Society and Energy Sector

    Directory of Open Access Journals (Sweden)

    L. A. Bolshov

    2016-01-01

    Full Text Available The article examines radiation and hygienic regulations with regard to the elimination of consequences of the Chernobyl NPP accident in the context of relationships with other aspects, primarily socio-economic and political factors. This experience is reasonable to take into account when defining criteria in other regulatory fields, for example, in radioactive waste classification and remediation of areas. The article presents an analysis of joint features and peculiarities of nuclear accidents in the industry and energy sectors. It is noted that the scale of global consequences of the Chernobyl NPP accident is defined by the large-scale release of radioactivity into the environment, as well as an affiliation of the nuclear installation with the energy sector. Large-scale radiation accidents affect the most diverse spheres of human activities, what, in its turn, evokes the reverse reaction from the society and its institutions, including involvement of political means of settlement. If the latter is seeing for criteria that are scientifically justified and feasible, then the preconditions for minimizing socio-economic impacts are created. In other cases, political decisions, such as nuclear units’ shutdown and phasing out of nuclear energy, appear to be an economic price which society, as a whole and a single industry sector, pay to compensate the negative public response. The article describes fundamental changes in approaches to ensure nuclear and radiation safety that occurred after the Chernobyl NPP accident. Multiple and negative consequences of the Chernobyl accident for human and society are balanced to some extent by a higher level of operational safety, emergency preparedness, and life-cycle safety. The article indicates that harmonization and ensuring consistency of regulations that involve different aspects of nuclear and radiation safety are important to implement practical solutions to the nuclear legacy problems. The

  12. Atmospheric transport patterns and possible consequences for the European North after a nuclear accident.

    Science.gov (United States)

    Baklanov, A; Mahura, A; Jaffe, D; Thaning, L; Bergman, R; Andres, R

    2002-01-01

    The main purpose of this study is to examine possible impacts and consequences of a hypothetical accident at the Kola nuclear plant in north-west Russia on different geographical regions: Scandinavia, central Europe, European FSU and Taymyr. The period studied is 1991-1996. An isentropic trajectory model has been used to calculate forward trajectories that originated over the nuclear accident region. Atmospheric transport patterns were identified using the isentropic trajectories and a cluster analysis technique. From the trajectory model results, a number of cases were chosen for examination in detail using more complete transport models. For this purpose, the models MATHEW/ADPIC, DERMA and a newly developed FOA Random Displacement Model have been used to simulate the radionuclide transport and contamination in the case of a nuclear accident and their results have been compared with those of the trajectory modelling. Estimation of the long-term consequences for populations after an accident has been performed for several specific dates by empirical models and correlation between fallout and doses to humans on the basis of the Chernobyl accident exposures in Scandinavia.

  13. Atmospheric transport patterns and possible consequences for the European North after a nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Baklanov, A. E-mail: alb@dmi.min.dk; Mahura, A.; Jaffe, D.; Thaning, L.; Bergman, R.; Andres, R

    2002-07-01

    The main purpose of this study is to examine possible impacts and consequences of a hypothetical accident at the Kola nuclear plant in north-west Russia on different geographical regions: Scandinavia, central Europe, European FSU and Taymyr. The period studied is 1991-1996. An isentropic trajectory model has been used to calculate forward trajectories that originated over the nuclear accident region. Atmospheric transport patterns were identified using the isentropic trajectories and a cluster analysis technique. From the trajectory model results, a number of cases were chosen for examination in detail using more complete transport models. For this purpose, the models MATHEW/ADPIC, DERMA and a newly developed FOA Random Displacement Model have been used to simulate the radionuclide transport and contamination in the case of a nuclear accident and their results have been compared with those of the trajectory modelling. Estimation of the long-term consequences for populations after an accident has been performed for several specific dates by empirical models and correlation between fallout and doses to humans on the basis of the Chernobyl accident exposures in Scandinavia.

  14. Consequences of tritium release to water pathways from postulated accidents in a DOE production reactor (U)

    Energy Technology Data Exchange (ETDEWEB)

    O' Kula, K.R.; Olson, R.L.; Hamby, D.M. (Savannah River Lab., Aiken, SC (United States))

    1992-03-01

    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 {times} 10{sup {minus}3} person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 {times} 10{sup {minus}2} person-Sv/PBq(2.4 {times} 10{sup {minus}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 paper suggests that application of regional models (1610 km radius) will indicate larger dose consequences from short-term tritium releases to the atmosphere than from comparable tritium source terms to water pathways.

  15. Radioecological consequences of a potential accident during transport of spent nuclear fuel along an Arctic coastline.

    Science.gov (United States)

    Iosjpe, M; Reistad, O; Amundsen, I B

    2009-02-01

    This article presents results pertaining to a risk assessment of the potential consequences of a hypothetical accident occurring during the transportation by ship of spent nuclear fuel (SNF) along an Arctic coastline. The findings are based on modelling of potential releases of radionuclides, radionuclide transport and uptake in the marine environment. Modelling work has been done using a revised box model developed at the Norwegian Radiation Protection Authority. Evaluation of the radioecological consequences of a potential accident in the southern part of the Norwegian Current has been made on the basis of calculated collective dose to man, individual doses for the critical group, concentrations of radionuclides in seafood and doses to marine organisms. The results of the calculations indicate a large variability in the investigated parameters above mentioned. On the basis of the calculated parameters the maximum total activity ("accepted accident activity") in the ship, when the parameters that describe the consequences after the examined potential accident are still in agreement with the recommendations and criterions for protection of the human population and the environment, has been evaluated.

  16. Modeling secondary accidents identified by traffic shock waves.

    Science.gov (United States)

    Junhua, Wang; Boya, Liu; Lanfang, Zhang; Ragland, David R

    2016-02-01

    The high potential for occurrence and the negative consequences of secondary accidents make them an issue of great concern affecting freeway safety. Using accident records from a three-year period together with California interstate freeway loop data, a dynamic method for more accurate classification based on the traffic shock wave detecting method was used to identify secondary accidents. Spatio-temporal gaps between the primary and secondary accident were proven be fit via a mixture of Weibull and normal distribution. A logistic regression model was developed to investigate major factors contributing to secondary accident occurrence. Traffic shock wave speed and volume at the occurrence of a primary accident were explicitly considered in the model, as a secondary accident is defined as an accident that occurs within the spatio-temporal impact scope of the primary accident. Results show that the shock waves originating in the wake of a primary accident have a more significant impact on the likelihood of a secondary accident occurrence than the effects of traffic volume. Primary accidents with long durations can significantly increase the possibility of secondary accidents. Unsafe speed and weather are other factors contributing to secondary crash occurrence. It is strongly suggested that when police or rescue personnel arrive at the scene of an accident, they should not suddenly block, decrease, or unblock the traffic flow, but instead endeavor to control traffic in a smooth and controlled manner. Also it is important to reduce accident processing time to reduce the risk of secondary accident. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Evaluation of severe accident risks: Quantification of major input parameters: MAACS (MELCOR Accident Consequence Code System) input

    Energy Technology Data Exchange (ETDEWEB)

    Sprung, J.L.; Jow, H-N (Sandia National Labs., Albuquerque, NM (USA)); Rollstin, J.A. (GRAM, Inc., Albuquerque, NM (USA)); Helton, J.C. (Arizona State Univ., Tempe, AZ (USA))

    1990-12-01

    Estimation of offsite accident consequences is the customary final step in a probabilistic assessment of the risks of severe nuclear reactor accidents. Recently, the Nuclear Regulatory Commission reassessed the risks of severe accidents at five US power reactors (NUREG-1150). Offsite accident consequences for NUREG-1150 source terms were estimated using the MELCOR Accident Consequence Code System (MACCS). Before these calculations were performed, most MACCS input parameters were reviewed, and for each parameter reviewed, a best-estimate value was recommended. This report presents the results of these reviews. Specifically, recommended values and the basis for their selection are presented for MACCS atmospheric and biospheric transport, emergency response, food pathway, and economic input parameters. Dose conversion factors and health effect parameters are not reviewed in this report. 134 refs., 15 figs., 110 tabs.

  18. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 1: Main report

    Energy Technology Data Exchange (ETDEWEB)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harrison, J.D. [National Radiological Protection Board (United Kingdom); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models.

  19. Probabilistic accident consequence uncertainty analysis -- Late health effects uncertainty assessment. Volume 1: Main report

    Energy Technology Data Exchange (ETDEWEB)

    Little, M.P.; Muirhead, C.R. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA late health effects models.

  20. Fukushima and Chernobyl accidents, a preliminary compared approach of their sanitary consequences; Accidents de Fukushima et Tchernobyl, une premiere approche comparee de leurs consequences sanitaires

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R. [Academie des technologies, 75 - Paris (France)

    2011-05-15

    It is too early to draw a definitive account of the sanitary impacts of the Fukushima accident but the author tries to assess them by comparing with Chernobyl accident. It appears that the sanitary consequences will be far less dramatic because of lower radiation doses and efficient counter-measures taken quickly after the accident such as evacuation of contaminated areas and restriction about the consumption of food produced locally. (A.C.)

  1. Reactor safety study. An assessment of accident risks in U. S. commercial nuclear power plants. Appendix VI. Calculation of reactor accident consequences. [PWR and BWR

    Energy Technology Data Exchange (ETDEWEB)

    1975-10-01

    Information is presented concerning the radioactive releases from the containment following accidents; radioactive inventory of the reactor core; atmospheric dispersion; reactor sites and meteorological data; radioactive decay and deposition from plumes; finite distance of plume travel; dosimetric models; health effects; demographic data; mitigation of radiation exposure; economic model; and calculated results with consequence model.

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

    Energy Technology Data Exchange (ETDEWEB)

    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 {times} 10{sup {minus}3} person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 {times} 10{sup {minus}2} person-Sv/Pbq (2.4 {times} 10{sup {minus}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. Consequences of tritium release to water pathways from postulated accidents in a DOE production reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-31

    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 {times} 10{sup {minus}3} person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 {times} 10{sup {minus}2} person-Sv/Pbq (2.4 {times} 10{sup {minus}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.

  4. Prevention of "simple accidents at work" with major consequences

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten

    2016-01-01

    of prevention or safety methodologies and procedures established for major accidents are applicable to simple accidents. The article goes back to basics about accidents causes, to review the nature of successful prevention techniques and to analyze what have been constraints to getting this knowledge used more...... occupational accidents a year were notified leading to 4500 fatalities and 90,000 permanent disabilities each year. The article looks at the concept ‘‘accident’’ to find similarities and distinctions between major and simple accident characteristics. The purpose is to find to what extent the same kinds......The concept ‘‘simple accidents’’ is understood as traumatic events with one victim. In the last 10 years many European countries have seen a decline in the number of fatalities, but there still remain many severe accidents at work. In the years 2009–2010 in European countries 2.0–2.4 million...

  5. Assessment of uncertainties in early off-site consequences from nuclear reactor accidents

    Energy Technology Data Exchange (ETDEWEB)

    Madni, I.K.; Cazzoli, E.G. (Brookhaven National Lab., Dept. of Nuclear Energy, Upton, NY (US)); Khatib-Rahbar, M. (Energy Research, Inc., Rockville, MD (US))

    1990-04-01

    A simplified approach has been developed to calculate uncertainties in early off-site consequences from nuclear reactor accidents. The consequence model (SMART) is based on a solution procedure that uses simplified meteorology and involves direct analytic integration of air concentration equations over time and position. This is different from the discretization approach currently used in the CRAC2 and MACCS codes. The SMART code is fast running, thereby providing a valuable tool for sensitivity and uncertainty studies. The code was benchmarked against both MACCS version 1.4 and CRAC2. Results of benchmarketing and detailed sensitivity and uncertainty analyses using SMART are presented.

  6. Health effects models for nuclear power plant accident consequence analysis: Modifications of models resulting from recent reports on health effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamson, S. (Wisconsin Univ., Madison, WI (United States)); Bender, M.A. (Brookhaven National Lab., Upton, NY (United States)); Boecker, B.B.; Scott, B.R. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.); Gilbert, E.S. (Pacific Northwest Lab., Richland, WA (United States))

    1991-08-01

    The Nuclear Regulatory Commission has sponsored several studies to identify and quantify the potential health effects of accidental releases of radionuclides from nuclear power plants. The most recent health effects models resulting from these efforts were published in two reports, NUREG/CR-4214, Rev. 1, Part 1 (1990) and Part 2 (1989). Several major health effects reports have been published recently that may impact the health effects models presented in these reports. This addendum to the Part 2 (1989) report, provides a review of the 1986 and 1988 reports by the United Nations Scientific Committee on the Effects of Atomic Radiation, the National Academy of Sciences/National Research Council BEAR 5 Committee report and Publication 60 of the International Commission on Radiological Protection as they relate to this report. The three main sections of this addendum discuss early occurring and continuing effects, late somatic effects, and genetic effects. The major changes to the NUREG/CR-4214 health effects models recommended in this addendum are for late somatic effects. These changes reflect recent changes in cancer risk factors that have come from longer followup and revised dosimetry in major studies like that on the Japanese A-bomb survivors. The results presented in this addendum should be used with the basic NUREG/CR-4214 reports listed above to obtain the most recent views on the potential health effects of radionuclides released accidentally from nuclear power plants. 48 refs., 4 figs., 24 tabs.

  7. Guide for licensing evaluations using CRAC2: A computer program for calculating reactor accident consequences

    Energy Technology Data Exchange (ETDEWEB)

    White, J.E.; Roussin, R.W.; Gilpin, H.

    1988-12-01

    A version of the CRAC2 computer code applicable for use in analyses of consequences and risks of reactor accidents in case work for environmental statements has been implemented for use on the Nuclear Regulatory Commission Data General MV/8000 computer system. Input preparation is facilitated through the use of an interactive computer program which operates on an IBM personal computer. The resulting CRAC2 input deck is transmitted to the MV/8000 by using an error-free file transfer mechanism. To facilitate the use of CRAC2 at NRC, relevant background material on input requirements and model descriptions has been extracted from four reports - ''Calculations of Reactor Accident Consequences,'' Version 2, NUREG/CR-2326 (SAND81-1994) and ''CRAC2 Model Descriptions,'' NUREG/CR-2552 (SAND82-0342), ''CRAC Calculations for Accident Sections of Environmental Statements, '' NUREG/CR-2901 (SAND82-1693), and ''Sensitivity and Uncertainty Studies of the CRAC2 Computer Code,'' NUREG/CR-4038 (ORNL-6114). When this background information is combined with instructions on the input processor, this report provides a self-contained guide for preparing CRAC2 input data with a specific orientation toward applications on the MV/8000. 8 refs., 11 figs., 10 tabs.

  8. Radioecological and dosimetric consequences of Chernobyl accident in France; Consequences radioecologiques et dosimetriques de l`accident de Tchernobyl en France

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, Ph.; Beaugelin, K.; Maubert, H.; Ledenvic, Ph

    1997-12-31

    After ten years and the taking in account of numerous data, it can be affirmed that the dosimetric consequences of Chernobyl accident will have been limited in France. for the period 1986-2046, the individual middle efficient dose commitment, for the area the most reached by depositing is inferior to 1500 {mu}Sv, that represents about 1% of middle natural exposure in the same time. but mountains and forests can have more important surface activities than in plain. Everywhere else, it can be considered that the effects of Chernobyl accident are disappearing. the levels of cesium 137 are now often inferior to what they were before the accident. (N.C.)

  9. Probabilistic accident consequence uncertainty analysis -- Late health effects uncertain assessment. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Little, M.P.; Muirhead, C.R. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA late health effects models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the expert panel on late health effects, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  10. Probabilistic accident consequence uncertainty analysis -- Early health effects uncertainty assessment. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Haskin, F.E. [Univ. of New Mexico, Albuquerque, NM (United States); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA early health effects models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on early health effects, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  11. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for deposited material and external doses. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Boardman, J. [AEA Technology (United Kingdom); Jones, J.A. [National Radiological Protection Board (United Kingdom); Harper, F.T.; Young, M.L. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA deposited material and external dose models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on deposited material and external doses, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  12. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harrison, J.D. [National Radiological Protection Board (United Kingdom); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  13. Genetic consequences of the Chernobyl accident for Belarus republic

    Energy Technology Data Exchange (ETDEWEB)

    Lazjuk, G.; Nikolaev, D.; Novikova, I. [Belarus Institute for Hereditary Diseases, Minsk (Belarus); Satow, Yukio

    1998-03-01

    various uncertainties. Only direct methods, which count the final effect, with all their drawbacks, can provide accurate information on genetic losses. We have estimated possible genetic consequences for the residents of Belarus Republic due to the Chernobyl accident by studying malformations found in legal medical abortuses and by counting congenital anomalies in fetuses and newborns. (J.P.N.)

  14. Consequences in Norway after a hypothetical accident at Sellafield - Predicted impacts on the environment

    Energy Technology Data Exchange (ETDEWEB)

    Thoerring, H.; Ytre-Eide, M.A.; Liland, A.

    2010-12-15

    This report describes the possible environmental consequences for Norway due to a hypothetical accident at the Sellafield complex in the UK. The scenario considered involves an explosion and fire at the B215 facility resulting in a 1 % release of the total HAL (Highly Active liquor) inventory of radioactive waste with a subsequent air transport and deposition in Norway. Air transport modelling is based on real meteorological data from October 2008 with wind direction towards Norway and heavy precipitation. This weather is considered to be quite representative as typical seasonal weather. Based on this weather scenario, the estimated fallout in Norway will be approx 17 P Bq of caesium-137 which is 7 times higher than the fallout from the Chernobyl accident. The modelled radioactive contamination is linked with data on transfer to the food chain and statistics on production and hunting to assess the consequences for foodstuffs. The investigation has been limited to the terrestrial environment, focussing on wild berries, fungi, and animals grazing unimproved pastures (i.e. various types of game, reindeer, sheep and goats). The predicted consequences are severe - especially in connection to sheep and goat production. Up to 80 % of the lambs in Norway could be exceeding the food intervention levels for radiocaesium the first years after the fallout, with 30-40 % likely to be above for many years. There will, consequently, be a need for extensive countermeasures in large areas for years or even decades involving several hundred thousand animals each year. Large consequences are also expected for reindeer husbandry - the first year in particular due to the time of fallout which is just prior to winter slaughter. The consequences will be most sever for reindeer herding in middle and southern parts of Norway, but problems may reach as far north as Finnmark where we find the majority of Norwegian reindeer production. The consequences for game will mostly depend on the

  15. Consequences and countermeasures in a nuclear power accident: Chernobyl experience.

    Science.gov (United States)

    Kirichenko, Vladimir A; Kirichenko, Alexander V; Werts, Day E

    2012-09-01

    Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination.

  16. The chernobyl accident 20 years on: an assessment of the health consequences and the international response.

    Science.gov (United States)

    Baverstock, Keith; Williams, Dillwyn

    2006-09-01

    The Chernobyl accident in 1986 caused widespread radioactive contamination and enormous concern. Twenty years later, the World Health Organization and the International Atomic Energy Authority issued a generally reassuring statement about the consequences. Accurate assessment of the consequences is important to the current debate on nuclear power. Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths ; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects, such as mini-satellite instability, which is potentially important. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment of Chernobyl's future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. Because of the uncertainties over the dose from and the consequences of the Chernobyl accident, it is essential that investigations of its effects should be broadened and supported for the long term. Because of the problems with the international response to Chernobyl, the United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry.

  17. Severe accident approach - final report. Evaluation of design measures for severe accident prevention and consequence mitigation.

    Energy Technology Data Exchange (ETDEWEB)

    Tentner, A. M.; Parma, E.; Wei, T.; Wigeland, R.; Nuclear Engineering Division; SNL; INL

    2010-03-01

    An important goal of the US DOE reactor development program is to conceptualize advanced safety design features for a demonstration Sodium Fast Reactor (SFR). The treatment of severe accidents is one of the key safety issues in the design approach for advanced SFR systems. It is necessary to develop an in-depth understanding of the risk of severe accidents for the SFR so that appropriate risk management measures can be implemented early in the design process. This report presents the results of a review of the SFR features and phenomena that directly influence the sequence of events during a postulated severe accident. The report identifies the safety features used or proposed for various SFR designs in the US and worldwide for the prevention and/or mitigation of Core Disruptive Accidents (CDA). The report provides an overview of the current SFR safety approaches and the role of severe accidents. Mutual understanding of these design features and safety approaches is necessary for future collaborations between the US and its international partners as part of the GEN IV program. The report also reviews the basis for an integrated safety approach to severe accidents for the SFR that reflects the safety design knowledge gained in the US during the Advanced Liquid Metal Reactor (ALMR) and Integral Fast Reactor (IFR) programs. This approach relies on inherent reactor and plant safety performance characteristics to provide additional safety margins. The goal of this approach is to prevent development of severe accident conditions, even in the event of initiators with safety system failures previously recognized to lead directly to reactor damage.

  18. Probabilistic accident consequence uncertainty analysis: Dispersion and deposition uncertainty assessment, appendices A and B

    Energy Technology Data Exchange (ETDEWEB)

    Harper, F.T.; Young, M.L.; Miller, L.A. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States); Lui, C.H. [Nuclear Regulatory Commission, Washington, DC (United States); Goossens, L.H.J.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Paesler-Sauer, J. [Research Center, Karlsruhe (Germany); Helton, J.C. [and others

    1995-01-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, completed in 1990, estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the Commission of the European Communities (CEC) began a joint uncertainty analysis of the two codes. The objective was to develop credible and traceable uncertainty distributions for the input variables of the codes. Expert elicitation, developed independently, was identified as the best technology available for developing a library of uncertainty distributions for the selected consequence parameters. The study was formulated jointly and was limited to the current code models and to physical quantities that could be measured in experiments. To validate the distributions generated for the wet deposition input variables, samples were taken from these distributions and propagated through the wet deposition code model along with the Gaussian plume model (GPM) implemented in the MACCS and COSYMA codes. Resulting distributions closely replicated the aggregated elicited wet deposition distributions. Project teams from the NRC and CEC cooperated successfully to develop and implement a unified process for the elaboration of uncertainty distributions on consequence code input parameters. Formal expert judgment elicitation proved valuable for synthesizing the best available information. Distributions on measurable atmospheric dispersion and deposition parameters were successfully elicited from experts involved in the many phenomenological areas of consequence analysis. This volume is the second of a three-volume document describing the project and contains two appendices describing the rationales for the dispersion and deposition data along with short biographies of the 16 experts who participated in the project.

  19. Probabilistic accident consequence uncertainty analysis: Dispersion and deposition uncertainty assessment, main report

    Energy Technology Data Exchange (ETDEWEB)

    Harper, F.T.; Young, M.L.; Miller, L.A. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States); Lui, C.H. [Nuclear Regulatory Commission, Washington, DC (United States); Goossens, L.H.J.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Paesler-Sauer, J. [Research Center, Karlsruhe (Germany); Helton, J.C. [and others

    1995-01-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the Commission of the European Communities (CEC) began a joint uncertainty analysis of the two codes. The ultimate objective of the joint effort was to develop credible and traceable uncertainty distributions for the input variables of the codes. Expert elicitation was identified as the best technology available for developing a library of uncertainty distributions for the selected consequence parameters. The study was formulated jointly and was limited to the current code models and to physical quantities that could be measured in experiments. Experts developed their distributions independently. To validate the distributions generated for the wet deposition input variables, samples were taken from these distributions and propagated through the wet deposition code model. Resulting distributions closely replicated the aggregated elicited wet deposition distributions. To validate the distributions generated for the dispersion code input variables, samples from the distributions and propagated through the Gaussian plume model (GPM) implemented in the MACCS and COSYMA codes. Project teams from the NRC and CEC cooperated successfully to develop and implement a unified process for the elaboration of uncertainty distributions on consequence code input parameters. Formal expert judgment elicitation proved valuable for synthesizing the best available information. Distributions on measurable atmospheric dispersion and deposition parameters were successfully elicited from experts involved in the many phenomenological areas of consequence analysis. This volume is the first of a three-volume document describing the project.

  20. Have the consequences of reactor accidents for the population been well assessed? Six questions to the experts in the field

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, Peter

    2016-07-15

    Six questions to the experts in the field are posed: (1) Why is the assessment of accident consequences not separated in long-term and peak exposure? (2) Why is the exposure due to I-131 seen critical mainly in regard to the thyroid? (3) Do you have any reliable relations of health risk versus peak exposure? (4) Why do you not abolish the LNT assumption and replace it with a threshold model? (5) Why do you include indirect, psycho-somatic effects in assessing the consequences of reactor accidents when this is not customary with accidents with often more casualties? (6) How can the number of Chernobyl-assigned thyroid cancers have risen from some 600 about to some 4,000 today, when the latency period is in the range of 4 to 5 years?.

  1. Preliminary Modeling of Accident Tolerant Fuel Concepts under Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle A.; Hales, Jason D.

    2016-12-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. Thus, the United States Department of Energy through its NEAMS (Nuclear Energy Advanced Modeling and Simulation) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is funded for a three-year period. The purpose of the HIP is to perform research into two potential accident tolerant concepts and provide an in-depth report to the Advanced Fuels Campaign (AFC) describing the behavior of the concepts, both of which are being considered for inclusion in a lead test assembly scheduled for placement into a commercial reactor in 2022. The initial focus of the HIP is on uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (INL, LANL, and ANL) a comprehensive mulitscale approach to modeling is being used including atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. In this paper, we present simulations of two proposed accident tolerant fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. The simulations investigate the fuel performance response of the proposed ATF systems under Loss of Coolant and Station Blackout conditions using the BISON code. Sensitivity analyses are completed using Sandia National Laboratories’ DAKOTA software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). Early results indicate that each concept has significant advantages as well as areas of concern. Further work is required prior to formulating the proposition report for the Advanced Fuels Campaign.

  2. CONSEQUENCES FOR HEALTH AFTER THE CHERNOBYL ACCIDENT: MAIN RESULTS AND UNSOLVED PROBLEMS

    Directory of Open Access Journals (Sweden)

    A. K. Gus’kova

    2011-01-01

    Full Text Available Data of researches of the consequences for health after the Chernobyl accident of 1986 are generalized. All these years all over the world and especially in our country the basic parameters were studied describing type and the reason of the accident, doses levels for various groups of persons and a condition of their physical and sincere health. Accumulation of the extensive information allows returning to the initial concepts which have arisen directly after the accident, to estimate critically reliability accepted at that time criteria and adequacy of measures for overcoming and minimization of the consequences of the accident for health. In a basis of an assessment of the exposure levels and possible consequences for health in early timeframes have been put the information on the capacity of doses scale-radiation on various distances from the damaged reactor both total activity and structure of emission of radioactive substances. Three basic groups of the persons involved in the emergency with a various combination of risk factors for their health are allocated: the personnel of emergency changes, participants of liquidation of the accident consequences, the population of emergency emission zones. Consequences for health for these groups and principles of the further supervision over them are estimated. The increase of leukemia among the reasons for death (5 of 21 attracts attention. The group of patients transferred acute radiation syndrome in connection with the Chernobyl accident differs for the reasons for death in the remote timeframes from participants of other radiating accidents. By retrospective consideration there is a question on a possibility of the insufficient account of toxic influences accompanying the exposure. Comparison of urgent decisions and the retrospective analysis of assessments during the early period of accident allow considering these early decisions adequate to volume of the information available during this

  3. Consequences in Norway after a hypothetical accident at Sellafield - Predicted impacts on the environment.

    Energy Technology Data Exchange (ETDEWEB)

    Thoerring, H.; Liland, A.

    2010-12-15

    This report deals with the environmental consequences in Norway after a hypothetical accident at Sellafield. The investigation is limited to the terrestrial environment, and focus on animals grazing natural pastures, plus wild berries and fungi. Only 137Cs is considered. The predicted consequences are severe, in particular for mutton and goat milk production. (Author)

  4. ASSESSMENT OF THE FUKUSIMA NUCLEAR POWER PLANT ACCIDENT CONSEQUENCES BY THE POPULATION IN THE FAR EAST

    Directory of Open Access Journals (Sweden)

    G. V. Arkhangelskaya

    2012-01-01

    Full Text Available The article analyzes the attitude of the population in the five regions of the Far East to the consequences of the accident at the Fukushimai nuclear power plant, as well as the issues of informing about the accident. The analysis of public opinion is based on the data obtained by anonymous questionnaire survey performed in November 2011. In spite of the rather active informing and objective information on the absence of the contamination, most of the population of the Russian Far East believes that radioactive contamination is presented in the areas of their residence, and the main cause of this contamination is the nuclear accident in Japan.

  5. Review of models applicable to accident aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, J.A.

    1983-07-01

    Estimations of potential airborne-particle releases are essential in safety assessments of nuclear-fuel facilities. This report is a review of aerosol behavior models that have potential applications for predicting aerosol characteristics in compartments containing accident-generated aerosol sources. Such characterization of the accident-generated aerosols is a necessary step toward estimating their eventual release in any accident scenario. Existing aerosol models can predict the size distribution, concentration, and composition of aerosols as they are acted on by ventilation, diffusion, gravity, coagulation, and other phenomena. Models developed in the fields of fluid mechanics, indoor air pollution, and nuclear-reactor accidents are reviewed with this nuclear fuel facility application in mind. The various capabilities of modeling aerosol behavior are tabulated and discussed, and recommendations are made for applying the models to problems of differing complexity.

  6. Consequences of the Chernobyl accident for reindeer husbandry in Sweden

    Directory of Open Access Journals (Sweden)

    Gustaf Åhman

    1990-09-01

    Full Text Available Large parts of the reindeer hearding area in Sweden were contaminated with radioactive caesium from the Chernobyl fallout. During the first year after the accident no food with activity concentrations exceeding 300 Bq/kg was allowed to be sold in Sweden. This meant that about 75% of all reindeer meat produced in Sweden during the autumn and winter 1986/87 were rejected because of too high caesium activités. In May 1987 the maximum level for Cs-137 in reindeer, game and fresh-water fish was raised to 1500 Bq/kg. During the last two year, 1987/88 and 1988/89, about 25% of the slaughtered reindeer has had activities exceeding this limit. The effective long-time halflife or radiocaesium in reindeer after the nuclear weapon tests in the sixties was about 7 years. If this halflife is correct also for the Chernobyl fallout it will take about 35 years before most of the reinder in Sweden are below the current limit 1500 Bq/kg in the winter. However, by feeding the animals uncontaminated food for about two months, many reindeer can be saved for human consumption.

  7. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for deposited material and external doses. Volume 1: Main report

    Energy Technology Data Exchange (ETDEWEB)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Boardman, J. [AEA Technology (United Kingdom); Jones, J.A. [National Radiological Protection Board (United Kingdom); Harper, F.T.; Young, M.L. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA deposited material and external dose models.

  8. RADIOLOGICAL AND MEDICAL CONSEQUENCES OF THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    V. G. Bebeshko

    2012-01-01

    Full Text Available From the position of a 25-years’ experience to overcome the health effects of Chernobyl the dynamics of the radiation environment, the first summarizing at the international level (1988, the results of completed research and practical monitoring are analyzed. Cohort of acute radiation syndrome (ARS survivors under medical observation at the S.I. "Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine" is the largest. Within the 25 years the functional state of the major organs and body systems, and metabolic homeostasis for this category of persons were studied, a comprehensive assessment of their health, mental and physical performance were given, and risk factors and peculiarities of stochastic and non-stochastic pathology courses were identified, as well as a system of rehabilitation patients after ARS was developed. ARS survivors are suffering from chronic diseases of internal organs and systems (from 5-7 to 10-12 diagnoses at the same time. A correlation between acute radiation effects and specific HLA phenotypes were revealed. The dynamics of the immune system recovery after irradiation was studied. The role and prognostic value of telomere length and programmed cell death of lymphocytes in the formation of the cellular effects of ionizing radiation were determined for the first time. Differences between spontaneous and radiation-induced acute myeloid leukemias were found. Dose-dependent neuropsychiatric, neurophysiological, neuropsychological and neuroimaging deviations were identified after irradiation at doses above 0.3 Sv. It was shown that the lymphocytes of Chernobyl clean-up workers with doses 350 – 690 mGy can induce "the bystander effect" in the non-irradiated cells even after 19 years after exposure. The rates of cancer incidence and mortality of victims, the lessons and key problems to be solved in the third decade after the Chernobyl accident are considered.

  9. Probabilistic accident consequence uncertainty analysis: Food chain uncertainty assessment. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)] [and others

    1997-06-01

    This volume is the second of a two-volume document that summarizes a joint project by the US Nuclear Regulatory and the Commission of European Communities to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This two-volume report, which examines mechanisms and uncertainties of transfer through the food chain, is the first in a series of five such reports. A panel of sixteen experts was formed to compile credible and traceable uncertainty distributions for food chain transfer that affect calculations of offsite radiological consequences. Seven of the experts reported on transfer into the food chain through soil and plants, nine reported on transfer via food products from animals, and two reported on both. The expert judgment elicitation procedure and its outcomes are described in these volumes. This volume contains seven appendices. Appendix A presents a brief discussion of the MAACS and COSYMA model codes. Appendix B is the structure document and elicitation questionnaire for the expert panel on soils and plants. Appendix C presents the rationales and responses of each of the members of the soils and plants expert panel. Appendix D is the structure document and elicitation questionnaire for the expert panel on animal transfer. The rationales and responses of each of the experts on animal transfer are given in Appendix E. Brief biographies of the food chain expert panel members are provided in Appendix F. Aggregated results of expert responses are presented in graph format in Appendix G.

  10. Evaluation of severe accident risks: Methodology for the containment, source term, consequence, and risk integration analyses; Volume 1, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gorham, E.D.; Breeding, R.J.; Brown, T.D.; Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Murfin, W.B. [Technadyne Engineering Consultants, Inc., Albuquerque, NM (United States); Hora, S.C. [Hawaii Univ., Hilo, HI (United States)

    1993-12-01

    NUREG-1150 examines the risk to the public from five nuclear power plants. The NUREG-1150 plant studies are Level III probabilistic risk assessments (PRAs) and, as such, they consist of four analysis components: accident frequency analysis, accident progression analysis, source term analysis, and consequence analysis. This volume summarizes the methods utilized in performing the last three components and the assembly of these analyses into an overall risk assessment. The NUREG-1150 analysis approach is based on the following ideas: (1) general and relatively fast-running models for the individual analysis components, (2) well-defined interfaces between the individual analysis components, (3) use of Monte Carlo techniques together with an efficient sampling procedure to propagate uncertainties, (4) use of expert panels to develop distributions for important phenomenological issues, and (5) automation of the overall analysis. Many features of the new analysis procedures were adopted to facilitate a comprehensive treatment of uncertainty in the complete risk analysis. Uncertainties in the accident frequency, accident progression and source term analyses were included in the overall uncertainty assessment. The uncertainties in the consequence analysis were not included in this assessment. A large effort was devoted to the development of procedures for obtaining expert opinion and the execution of these procedures to quantify parameters and phenomena for which there is large uncertainty and divergent opinions in the reactor safety community.

  11. Summary of the consequences for the environment of the Chernobyl accident; Synthese sur les consequences environnementales de l`accident de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Ciffroy, P.

    1996-08-01

    The main conclusions on the environmental consequences of the Chernobyl accident in the former Soviet Union can be summarised as follows: the long term radioactive contamination of the environment can essentially be put down to Cs and Sr and, to a lesser degree, transuranic elements. In the short term, the radioactive iodine fall-out plays a fundamental role; in the countries of the former Soviet Union, it is estimated that 29,300 and 10,200 km{sup 2} of the surface area of the land are respectively contaminated by over 185 and 555 kBq.m{sup -2}. Approximately 1,064,000 people live in areas contaminated by more than 185 kBq.m{sup -2}; acute radioactive fall-out effects have occurred in the 30 km exclusion zone, essentially witnessed by the death of numerous conifers. On average, it will take about twenty years for half the Cs to disappear from the top 10 cm of soil; the level of contamination of food products varies greatly according to soil type. However, we can consider that milk, berries and mushrooms were the most critical foods in the years immediately following the accident and that some of the agricultural counter-measures taken have proved very useful in containing the contamination of food products. Because of the massive iodine leakage, the worst affected organ in the body during the months following the accident was the thyroid gland. In the months following the accident, the presence of radioactive elements on the surface of vegetables which were subsequently eaten proved to be the main source of human contamination; after a rapid fall off in external dose received by the population during the first year, it is now decreasing much more slowly. This phenomenon is mainly due to the very long-life of the radioactive caesium in the soil; approximately 90 % of the total internal dose for the 70 years following the accident have already been received by the local population. The external dose level will be reduced fairly slowly and we can assess that

  12. Accident sequence precursor analysis level 2/3 model development

    Energy Technology Data Exchange (ETDEWEB)

    Lui, C.H. [Nuclear Regulatory Commission, Washington, DC (United States); Galyean, W.J.; Brownson, D.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1997-02-01

    The US Nuclear Regulatory Commission`s Accident Sequence Precursor (ASP) program currently uses simple Level 1 models to assess the conditional core damage probability for operational events occurring in commercial nuclear power plants (NPP). Since not all accident sequences leading to core damage will result in the same radiological consequences, it is necessary to develop simple Level 2/3 models that can be used to analyze the response of the NPP containment structure in the context of a core damage accident, estimate the magnitude of the resulting radioactive releases to the environment, and calculate the consequences associated with these releases. The simple Level 2/3 model development work was initiated in 1995, and several prototype models have been completed. Once developed, these simple Level 2/3 models are linked to the simple Level 1 models to provide risk perspectives for operational events. This paper describes the methods implemented for the development of these simple Level 2/3 ASP models, and the linkage process to the existing Level 1 models.

  13. Advanced accident sequence precursor analysis level 2 models

    Energy Technology Data Exchange (ETDEWEB)

    Galyean, W.J.; Brownson, D.A.; Rempe, J.L. [and others

    1996-03-01

    The U.S. Nuclear Regulatory Commission Accident Sequence Precursor program pursues the ultimate objective of performing risk significant evaluations on operational events (precursors) occurring in commercial nuclear power plants. To achieve this objective, the Office of Nuclear Regulatory Research is supporting the development of simple probabilistic risk assessment models for all commercial nuclear power plants (NPP) in the U.S. Presently, only simple Level 1 plant models have been developed which estimate core damage frequencies. In order to provide a true risk perspective, the consequences associated with postulated core damage accidents also need to be considered. With the objective of performing risk evaluations in an integrated and consistent manner, a linked event tree approach which propagates the front end results to back end was developed. This approach utilizes simple plant models that analyze the response of the NPP containment structure in the context of a core damage accident, estimate the magnitude and timing of a radioactive release to the environment, and calculate the consequences for a given release. Detailed models and results from previous studies, such as the NUREG-1150 study, are used to quantify these simple models. These simple models are then linked to the existing Level 1 models, and are evaluated using the SAPHIRE code. To demonstrate the approach, prototypic models have been developed for a boiling water reactor, Peach Bottom, and a pressurized water reactor, Zion.

  14. Probabilistic accident consequence uncertainty analysis: Food chain uncertainty assessment. Volume 1: Main report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)] [and others

    1997-06-01

    This volume is the first of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This document reports on an ongoing project to assess uncertainty in the MACCS and COSYMA calculations for the offsite consequences of radionuclide releases by hypothetical nuclear power plant accidents. A panel of sixteen experts was formed to compile credible and traceable uncertainty distributions for food chain variables that affect calculations of offsite consequences. The expert judgment elicitation procedure and its outcomes are described in these volumes. Other panels were formed to consider uncertainty in other aspects of the codes. Their results are described in companion reports. Volume 1 contains background information and a complete description of the joint consequence uncertainty study. Volume 2 contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures for both panels, (3) the rationales and results for the panels on soil and plant transfer and animal transfer, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  15. Consequences to health of the Chernobyl accident; Helbredsmaessige konsekvenser af reaktorulykken i Tjernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Sewerin, I. [Royal Dental College, Dept. of Radiology, Copenhagen (Denmark)

    2001-07-01

    The Chernobyl accident in 1986 has been and still is the subject of great interest. Journalistic reports often contain exaggerations and undocumented statements and much uncertainty about the true consequences of the accident prevails in the population. This article reviews the current literature with the focus on reports from official commissions and documentation in the form of controlled studies. The fatal deterministic consequences comprise about 30 victims. The most important outcome is a marked increase in the incidence of thyroid cancer in children and adolescents in the most heavily contaminated area. Furthermore, pronounced psychosocial problems are dominant in the population of the contaminated area. Other significant and documented health consequences are not seen. (au)

  16. RADIATION-HYGIENIC AND MEDICAL CONSEQUENCES OF THE СHERNOBYL ACCIDENT: RESULTS AND PROGNOSIS

    Directory of Open Access Journals (Sweden)

    G. G. Onischenko

    2011-01-01

    Full Text Available An article is devoted to the analysis of the radiation situation in the dynamics during the years since the accident at the Chernobyl nuclear power plant in 1986. Data on the scope of activities fulfilled for the assessment of the territories radioactive contamination levels and foodstuffs contamination levels, on the values of the exposure doses for the population living on the contaminated territories, on the medical and socio-psychological consequences of the Chernobyl accident is presented. Basic norms and principles, used during the protective measures development and introduction, are considered, their effectiveness is demonstrated. Mistakes emerged during protective measures implementation are analyzed, the prognosis of the population exposure dose values for the 70-year period since the accident and main directions of activities for the contaminated territories remediation and normal life conditions restoration for the population at these territories are presented.

  17. Two decades of radiological accidents direct causes, roots causes and consequences

    Directory of Open Access Journals (Sweden)

    Rozental Jose de Julio

    2002-01-01

    Full Text Available Practically all Countries utilize radioisotopes in medicine, industry, agriculture and research. The extent to which ionizing radiation practices are employed varies considerably, depending largely upon social and economic conditions and the level of technical skills available in the country. An overview of the majority of practices and the associated hazards will be found in the Table IV to VII of this document. The practices in normal and abnormal operating conditions should follow the basic principles of radiation protection and the Safety of Radiation Sources, considering the IAEA Radiation Protection and the Safety of Radiation Sources, Safety Series 120 and the IAEA Recommendation of the Basic Safety Standards for Radiation Protection, Safety Series Nº 115. The Standards themselves underline the necessity to be able to predict the radiological consequences of emergency conditions and the investigations that should need to be done. This paper describes the major accidents that had happened in the last two decades, provides a methodology for analyses and gives a collection of lessons learned. This will help the Regulatory Authority to review the reasons of vulnerabilities, and to start a Radiation safety and Security Programme to introduce measurescapable to avoid the recurrence of similar events. Although a number of accidents with fatalities have caught the attention of the public in recent year, a safety record has accompanied the widespread use of radiation sources. However, the fact that accidents are uncommon should not give grounds for complacency. No radiological accident is acceptable. From a radiation safety and security of the sources standpoint, accident investigation is necessary to determine what happened, why, when, where and how it occurred and who was (were involved and responsible. The investigation conclusion is an important process toward alertness and feedback to avoid careless attitudes by improving the comprehension

  18. [Short-term psychological consequences of car accidents: an empirical study].

    Science.gov (United States)

    Prunas, Antonio; Iavarone, Valentina; Fiorletta, Angela; Madeddu, Fabio

    2009-01-01

    Aim of this study is to investigate short-term (3 and 5 months) psychological consequences of severe motor-vehicle accidents. The sample under investigation is composed of two groups: 8 survivors of severe motor-vehicle accidents with spinal cord injuries (SCI) hospitalized in a Spinal Cord Unit, and 6 survivors who did not require hospitalization. All subjects were assessed twice, three and five months after the accident, on a variety of measures including the CAPS and the BDI-SF. Prevalence of PTSD in the total sample was, 3 months after the accident, 14% with no significant differences between the two groups; some peculiarities in the symptomathological profile emerged as much as subjects with SCI experience avoidance of trauma-related stimuli more frequently. An overall decline in frequency and severity of post-traumatic symptoms between the two assessments was observed in the total sample, though some components (Criterion C symptoms) showed no relevant variations over time. Finally, depressive symptoms, which were characterized by higher severity in the SCI group, showed a significant decline between the two assessments. Our data, although based on a limited sample, might help in tailoring psychological interventions for prevention and treatment of PTSD in survivors of severe motor accidents.

  19. Final report of the accident phenomenology and consequence (APAC) methodology evaluation. Spills Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Brereton, S.; Shinn, J. [Lawrence Livermore National Lab., CA (United States); Hesse, D [Battelle Columbus Labs., OH (United States); Kaninich, D. [Westinghouse Savannah River Co., Aiken, SC (United States); Lazaro, M. [Argonne National Lab., IL (United States); Mubayi, V. [Brookhaven National Lab., Upton, NY (United States)

    1997-08-01

    The Spills Working Group was one of six working groups established under the Accident Phenomenology and Consequence (APAC) methodology evaluation program. The objectives of APAC were to assess methodologies available in the accident phenomenology and consequence analysis area and to evaluate their adequacy for use in preparing DOE facility safety basis documentation, such as Basis for Interim Operation (BIO), Justification for Continued Operation (JCO), Hazard Analysis Documents, and Safety Analysis Reports (SARs). Additional objectives of APAC were to identify development needs and to define standard practices to be followed in the analyses supporting facility safety basis documentation. The Spills Working Group focused on methodologies for estimating four types of spill source terms: liquid chemical spills and evaporation, pressurized liquid/gas releases, solid spills and resuspension/sublimation, and resuspension of particulate matter from liquid spills.

  20. Calculations of reactor-accident consequences, Version 2. CRAC2: computer code user's guide

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, L.T.; Johnson, J.D.; Blond, R.M.

    1983-02-01

    The CRAC2 computer code is a revision of the Calculation of Reactor Accident Consequences computer code, CRAC, developed for the Reactor Safety Study. The CRAC2 computer code incorporates significant modeling improvements in the areas of weather sequence sampling and emergency response, and refinements to the plume rise, atmospheric dispersion, and wet deposition models. New output capabilities have also been added. This guide is to facilitate the informed and intelligent use of CRAC2. It includes descriptions of the input data, the output results, the file structures, control information, and five sample problems.

  1. Radiological consequences of accidents during disposal of spent nuclear fuel in a deep borehole

    Energy Technology Data Exchange (ETDEWEB)

    Grundfelt, Bertil [Kemakta Konsult AB, Stockholm (Sweden)

    2013-07-15

    In this report, an analysis of the radiological consequences of potential accidents during disposal of spent nuclear fuel in deep boreholes is presented. The results presented should be seen as coarse estimates of possible radiological consequences of a canister being stuck in a borehole during disposal rather than being the results of a full safety analysis. In the concept for deep borehole disposal of spent nuclear fuel developed by Sandia National Laboratories, the fuel is assumed to be encapsulated in mild steel canisters and stacked between 3 and 5 km depth in boreholes that are cased with perforated mild steel casing tubes. The canisters are joined together by couplings to form strings of 40 canisters and lowered into the borehole. When a canister string has been emplaced in the borehole, a bridge plug is installed above the string and a 10 metres long concrete plug is cast on top of the bridge plug creating a floor for the disposal of the next sting. In total 10 canister strings, in all 400 canisters, are assumed to be disposed of at between 3 and 5 kilometres depth in one borehole. An analysis of potential accidents during the disposal operations shows that the potentially worst accident would be that a canister string is stuck above the disposal zone of a borehole and cannot be retrieved. In such a case, the borehole may have to be sealed in the best possible way and abandoned. The consequences of this could be that one or more leaking canisters are stuck in a borehole section with mobile groundwater. In the case of a leaking canister being stuck in a borehole section with mobile groundwater, the potential radiological consequences are likely to be dominated by the release of the so-called Instant Release Fraction (IRF) of the radionuclide inventory, i.e. the fraction of the radionuclides that as a consequence of the in-core conditions are present in the annulus between the fuel pellets and the cladding or on the grain boundaries of the UO{sub 2} matrix

  2. Probabilistic accident consequence uncertainty analysis: Dispersion and deposition uncertainty assessment. Volume 3, Appendices C, D, E, F, and G

    Energy Technology Data Exchange (ETDEWEB)

    Harper, F.T.; Young, M.L.; Miller, L.A. [Sandia National Labs., Albuquerque, NM (United States)] [and others

    1995-01-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, completed in 1990, estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the Commission of the European Communities (CEC) began a joint uncertainty analysis of the two codes. The objective was to develop credible and traceable uncertainty distributions for the input variables of the codes. Expert elicitation, developed independently, was identified as the best technology available for developing a library of uncertainty distributions for the selected consequence parameters. The study was formulated jointly and was limited to the current code models and to physical quantities that could be measured in experiments. To validate the distributions generated for the wet deposition input variables, samples were taken from these distributions and propagated through the wet deposition code model along with the Gaussian plume model (GPM) implemented in the MACCS and COSYMA codes. Resulting distributions closely replicated the aggregated elicited wet deposition distributions. Project teams from the NRC and CEC cooperated successfully to develop and implement a unified process for the elaboration of uncertainty distributions on consequence code input parameters. Formal expert judgment elicitation proved valuable for synthesizing the best available information. Distributions on measurable atmospheric dispersion and deposition parameters were successfully elicited from experts involved in the many phenomenological areas of consequence analysis. This volume is the third of a three-volume document describing the project and contains descriptions of the probability assessment principles; the expert identification and selection process; the weighting methods used; the inverse modeling methods; case structures; and summaries of the consequence codes.

  3. Motorcycle accidents, rider behaviour, and psychological models.

    Science.gov (United States)

    Özkan, Türker; Lajunen, Timo; Doğruyol, Burak; Yıldırım, Zümrüt; Çoymak, Ahmet

    2012-11-01

    The aims of the present study were to: (a) investigate the factor structure of the Motorcycle Rider Behaviour Questionnaire (MRBQ) [Elliott, M.A., Baughan, B.J., Sexton, B.F., 2007. Errors and violations in relation to motorcyclists' crash risk. Accident Analysis and Prevention 39, 491-499] in among Turkish riders, and (b) study the relationships between different types of rider behaviour and motorcyclists' active and passive accidents and offences, and (c) investigate the usefulness of the Theory of Planned Behaviour (TPB), Health Belief Model (HBM), and Locus of Control (T-LOC) in explaining rider behaviours. MRBQ was administered to a sample of motorcyclists (N=451). Principal components analysis yielded a 5-factor solution including traffic errors, control errors, speed violations, performance of stunts, and use of safety equipment. Annual mileage was related to higher number of active and passive accidents and offences whereas age was related to lower number of active and passive accidents. Stunts were the main predictors of active accidents and offences. Speeding violations predicted offences. Stunts and speeding violations were associated with the fate factor of the T-LOC, and with attitudes, subjective norms, and intention components of TPB, and cues to action and perceived severity components of the HBM. Use of safety equipment was related to the high level of perceived behavioural control and intention components of the TPB, the low score of perceived barriers component of the HBM, and the low fate factor of the T-LOC. While traffic errors were associated with the high score of perceived barriers and cues to action component of the HBM, control errors were related to the high score of vehicle and environment factor of the T-LOC. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. ACCIDENT PREDICTION MODELS FOR UNSIGNALISED URBAN JUNCTIONS IN GHANA

    Directory of Open Access Journals (Sweden)

    Mohammed SALIFU, MSc., PhD, MIHT, MGhIE

    2004-01-01

    The accident prediction models developed have a potentially wide area of application and their systematic use is likely to improve considerably the quality and delivery of the engineering aspects of accident mitigation and prevention in Ghana.

  5. Degraded core accidents for the Sizewell PWR A sensitivity analysis of the radiological consequences

    CERN Document Server

    Kelly, G N; Clarke, R H; Ferguson, L; Haywood, S M; Hemming, C R; Jones, J A

    1982-01-01

    The radiological impact of degraded core accidents postulated for the Sizewell PWR was assessed in an earlier study. In this report the sensitivity of the predicted consequences to variation in the values of a number of important parameters is investigated for one of the postulated accidental releases. The parameters subjected to sensitivity analyses are the dose-mortality relationship for bone marrow irradiation, the energy content of the release, the warning time before the release to the environment, and the dry deposition velocity for airborne material. These parameters were identified as among the more important in determining the uncertainty in the results obtained in the initial study. With a few exceptions the predicted consequences were found to be not very sensitive to the parameter values investigated, the range of variation in the consequences for the limiting values of each parameter rarely exceeded a factor of a few and in many cases was considerably less. The conclusions reached are, however, p...

  6. Accident prediction model for public highway-rail grade crossings.

    Science.gov (United States)

    Lu, Pan; Tolliver, Denver

    2016-05-01

    Considerable research has focused on roadway accident frequency analysis, but relatively little research has examined safety evaluation at highway-rail grade crossings. Highway-rail grade crossings are critical spatial locations of utmost importance for transportation safety because traffic crashes at highway-rail grade crossings are often catastrophic with serious consequences. The Poisson regression model has been employed to analyze vehicle accident frequency as a good starting point for many years. The most commonly applied variations of Poisson including negative binomial, and zero-inflated Poisson. These models are used to deal with common crash data issues such as over-dispersion (sample variance is larger than the sample mean) and preponderance of zeros (low sample mean and small sample size). On rare occasions traffic crash data have been shown to be under-dispersed (sample variance is smaller than the sample mean) and traditional distributions such as Poisson or negative binomial cannot handle under-dispersion well. The objective of this study is to investigate and compare various alternate highway-rail grade crossing accident frequency models that can handle the under-dispersion issue. The contributions of the paper are two-fold: (1) application of probability models to deal with under-dispersion issues and (2) obtain insights regarding to vehicle crashes at public highway-rail grade crossings.

  7. Exact results for car accidents in a traffic model

    Science.gov (United States)

    Huang, Ding-wei

    1998-07-01

    Within the framework of a recent model for car accidents on single-lane highway traffic, we study analytically the probability of the occurrence of car accidents. Exact results are obtained. Various scaling behaviours are observed. The linear dependence of the occurrence of car accidents on density is understood as the dominance of a single velocity in the distribution.

  8. Decision Tree Model for Non-Fatal Road Accident Injury

    Directory of Open Access Journals (Sweden)

    Fatin Ellisya Sapri

    2017-02-01

    Full Text Available Non-fatal road accident injury has become a great concern as it is associated with injury and sometimes leads to the disability of the victims. Hence, this study aims to develop a model that explains the factors that contribute to non-fatal road accident injury severity. A sample data of 350 non-fatal road accident cases of the year 2016 were obtained from Kota Bharu District Police Headquarters, Kelantan. The explanatory variables include road geometry, collision type, accident time, accident causes, vehicle type, age, airbag, and gender. The predictive data mining techniques of decision tree model and multinomial logistic regression were used to model non-fatal road accident injury severity. Based on accuracy rate, decision tree with CART algorithm was found to be more accurate as compared to the logistic regression model. The factors that significantly contribute to non-fatal traffic crashes injury severity are accident cause, road geometry, vehicle type, age and collision type.

  9. MELCOR modeling of Fukushima unit 2 accident

    Energy Technology Data Exchange (ETDEWEB)

    Sevon, Tuomo [VTT Technical Research Centre of Finland, Espoo (Finland)

    2014-12-15

    A MELCOR model of the Fukushima Daiichi unit 2 accident was created in order to get a better understanding of the event and to improve severe accident modeling methods. The measured pressure and water level could be reproduced relatively well with the calculation. This required adjusting the RCIC system flow rates and containment leak area so that a good match to the measurements is achieved. Modeling of gradual flooding of the torus room with water that originated from the tsunami was necessary for a satisfactory reproduction of the measured containment pressure. The reactor lower head did not fail in this calculation, and all the fuel remained in the RPV. 13 % of the fuel was relocated from the core area, and all the fuel rods lost their integrity, releasing at least some volatile radionuclides. According to the calculation, about 90 % of noble gas inventory and about 0.08 % of cesium inventory was released to the environment. The release started 78 h after the earthquake, and a second release peak came at 90 h. Uncertainties in the calculation are very large because there is scarce public data available about the Fukushima power plant and because it is not yet possible to inspect the status of the reactor and the containment. Uncertainty in the calculated cesium release is larger than factor of ten.

  10. The radiological consequences of degraded core accidents for the Sizewell PWR The impact of adopting revised frequencies of occurrence

    CERN Document Server

    Kelly, G N

    1983-01-01

    The radiological consequences of degraded core accidents postulated for the Sizewell PWR were assessed in an earlier study and the results published in NRPB-R137. Further analyses have since been made by the Central Electricity Generating Board (CEGB) of degraded core accidents which have led to a revision of their predicted frequencies of occurrence. The implications of these revised frequencies, in terms of the risk to the public from degraded core accidents, are evaluated in this report. Increases, by factors typically within the range of about 1.5 to 7, are predicted in the consequences, compared with those estimated in the earlier study. However, the predicted risk from degraded core accidents, despite these increases, remains exceedingly small.

  11. Accident consequences analysis of the HYLIFE-II inertial fusion energy power plant design

    Science.gov (United States)

    Reyes, S.; Latkowski, J. F.; Gomez del Rio, J.; Sanz, J.

    2001-05-01

    Previous studies of the safety and environmental aspects of the HYLIFE-II inertial fusion energy power plant design have used simplistic assumptions in order to estimate radioactivity releases under accident conditions. Conservatisms associated with these traditional analyses can mask the actual behavior of the plant and have revealed the need for more accurate modeling and analysis of accident conditions and radioactivity mobilization mechanisms. In the present work, computer codes traditionally used for magnetic fusion safety analyses (CHEMCON, MELCOR) have been applied for simulating accident conditions in a simple model of the HYLIFE-II IFE design. Here we consider a severe loss of coolant accident (LOCA) in conjunction with simultaneous failures of the beam tubes (providing a pathway for radioactivity release from the vacuum vessel towards the confinement) and of the two barriers surrounding the chamber (inner shielding and confinement building itself). Even though confinement failure would be a very unlikely event it would be needed in order to produce significant off-site doses. CHEMCON code allows calculation of long-term temperature transients in fusion reactor first wall, blanket, and shield structures resulting from decay heating. MELCOR is used to simulate a wide range of physical phenomena including thermal-hydraulics, heat transfer, aerosol physics and fusion product transport and release. The results of these calculations show that the estimated off-site dose is less than 5 mSv (0.5 rem), which is well below the value of 10 mSv (1 rem) given by the DOE Fusion Safety Standards for protection of the public from exposure to radiation during off-normal conditions.

  12. Accident consequences analysis of the HYLIFE-II inertial fusion energy power plant design

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S; Gomez del Rio, J; Sanz, J

    2000-02-23

    Previous studies of the safety and environmental (S and E) aspects of the HYLIFE-II inertial fusion energy (IFE) power plant design have used simplistic assumptions in order to estimate radioactivity releases under accident conditions. Conservatisms associated with these traditional analyses can mask the actual behavior of the plant and have revealed the need for more accurate modeling and analysis of accident conditions and radioactivity mobilization mechanisms. In the present work a set of computer codes traditionally used for magnetic fusion safety analyses (CHEMCON, MELCOR) has been applied for simulating accident conditions in a simple model of the HYLIFE-II IFE design. Here the authors consider a severe lost of coolant accident (LOCA) producing simultaneous failures of the beam tubes (providing a pathway for radioactivity release from the vacuum vessel towards the containment) and of the two barriers surrounding the chamber (inner shielding and containment building it self). Even though containment failure would be a very unlikely event it would be needed in order to produce significant off-site doses. CHEMCON code allows calculation of long-term temperature transients in fusion reactor first wall, blanket, and shield structures resulting from decay heating. MELCOR is used to simulate a wide range of physical phenomena including thermal-hydraulics, heat transfer, aerosol physics and fusion product release and transport. The results of these calculations show that the estimated off-site dose is less than 6 mSv (0.6 rem), which is well below the value of 10 mSv (1 rem) given by the DOE Fusion Safety Standards for protection of the public from exposure to radiation during off-normal conditions.

  13. Development of MAAP5.0.3 Spent Fuel Pool Model for Severe Accident Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Mi Ro [KHNP-CRI, Daejeon (Korea, Republic of)

    2015-10-15

    After the Fukushima accident, the severe accident phenomena in the Spent Fuel Pool (SFP) have been the great issues in the nuclear industry. Generally, during full power operation status, the decay heat of the spent fuel in the SFP is not high enough to cause the severe accident that is the say, the melting of fuel and fuel rack. In addition to this, the SFP of the PWR is not isolated within the containment like the SFP of the old BWR plant, there are so many possible measures to prevent and mitigate severe accidents in the SFP. On the other hand, in the low power shutdown status (fuel refueling), all the core is transferred into the SFP during the refueling period. At this period, if some accidents happen such as the loss of SFP cooling and the failure of SFP integrity then the accidents may be developed into severe accident because the decay heat is high enough. So, the analysis of severe accidents in the SFP during low power shutdown state is greatly affected to the establishment of the major strategies in the severe accident management guideline (SAMG). However, the status of the domestic technical background for those analyses is very weak. it is known that the decay heat of the spent fuel in the SFP is not high enough to cause the severe accident qualitatively. However, there are some possibilities that can cause the severe accidents in the SFP if the loss of SFP cooling and integrity happens simultaneously. The severe accident phenomena in SFP themselves are not much different from those in the containment. However, since the structure of SFP cannot be isolated during the accidents like the containment, the consequence can be extremely significant. So, in terms of the establishment of the severe accident management strategy, it is necessary that the quantitative analysis for the severe accident progression in the SFP should be performed. In this study, the general behavior which can be appeared during the severe accidents in the SFP was analyzed using the

  14. Modeling accident frequency in Denmark for improving road safety

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Hels, Tove; Kaplan, Sigal

    Traffic accidents result in huge costs to society in terms of death, injury, lost productivity, and property damage. The main objective of the current study is the development of an accident frequency model that predicts the expected number of accidents on a given road segment, provided...... concerning police recorded accidents, link characteristics of the road network, traffic volumes from the national transport models are merged to estimate the model. Spatial correlation between road sections is taken into account for correcting for unobserved correlation between contiguous locations....

  15. Evaluation of the Consequences of a Cistern Truck Accident While Transporting Dangerous Substances through a Tunnel.

    Science.gov (United States)

    Malecha, Ziemowit M; Poliski, Jarosaw; Chorowski, Maciej

    2017-03-23

    The transportation of dangerous substances by truck carriers harbors important safety issues in both road and mine tunnels. Even though traffic conditions in road and mine tunnels are different, the potential geometric and hydrodynamic similarities can lead to similar effects from the uncontrolled leakage of the dangerous material. This work was motivated by the design study of the LAGUNA-LBNO (Large Apparatus studying Grand Unification and Neutrino Astrophysics and Long Baseline Neutrino Oscillations) project. The considered neutrino detector requires a huge amount of liquid argon, which must be transported down the tunnel. The present work focuses on the estimation of the most credible incident and the resulting consequences in the case of a truck accident in the tunnel. The approach and tools used in the present work are generic and can be adapted to other similar situations. © 2017 Society for Risk Analysis.

  16. A 25 year retrospective review of the psychological consequences of the Chernobyl accident.

    Science.gov (United States)

    Bromet, E J; Havenaar, J M; Guey, L T

    2011-05-01

    The Chernobyl Forum Report from the 20th anniversary of the Chernobyl nuclear power plant disaster concluded that mental health effects were the most significant public health consequence of the accident. This paper provides an updated review of research on the psychological impact of the accident during the 25 year period since the catastrophe began. First responders and clean-up workers had the greatest exposure to radiation. Recent studies show that their rates of depression and post-traumatic stress disorder remain elevated two decades later. Very young children and those in utero who lived near the plant when it exploded or in severely contaminated areas have been the subject of considerable research, but the findings are inconsistent. Recent studies of prenatally exposed children conducted in Kiev, Norway and Finland point to specific neuropsychological and psychological impairments associated with radiation exposure, whereas other studies found no significant cognitive or mental health effects in exposed children grown up. General population studies report increased rates of poor self-rated health as well as clinical and subclinical depression, anxiety, and post-traumatic stress disorder. Mothers of young children exposed to the disaster remain a high-risk group for these conditions, primarily due to lingering worries about the adverse health effects on their families. Thus, long-term mental health consequences continue to be a concern. The unmet need for mental health care in affected regions remains an important public health challenge 25 years later. Future research is needed that combines physical and mental health outcome measures to complete the clinical picture. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  17. An overview of current knowledge concerning the health and environmental consequences of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident.

    Science.gov (United States)

    Aliyu, Abubakar Sadiq; Evangeliou, Nikolaos; Mousseau, Timothy Alexander; Wu, Junwen; Ramli, Ahmad Termizi

    2015-12-01

    Since 2011, the scientific community has worked to identify the exact transport and deposition patterns of radionuclides released from the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan. Nevertheless, there still remain many unknowns concerning the health and environmental impacts of these radionuclides. The present paper reviews the current understanding of the FDNPP accident with respect to interactions of the released radionuclides with the environment and impacts on human and non-human biota. Here, we scrutinize existing literature and combine and interpret observations and modeling assessments derived after Fukushima. Finally, we discuss the behavior and applications of radionuclides that might be used as tracers of environmental processes. This review focuses on (137)Cs and (131)I releases derived from Fukushima. Published estimates suggest total release amounts of 12-36.7PBq of (137)Cs and 150-160PBq of (131)I. Maximum estimated human mortality due to the Fukushima nuclear accident is 10,000 (due to all causes) and the maximum estimates for lifetime cancer mortality and morbidity are 1500 and 1800, respectively. Studies of plants and animals in the forests of Fukushima have recorded a range of physiological, developmental, morphological, and behavioral consequences of exposure to radioactivity. Some of the effects observed in the exposed populations include the following: hematological aberrations in Fukushima monkeys; genetic, developmental and morphological aberrations in a butterfly; declines in abundances of birds, butterflies and cicadas; aberrant growth forms in trees; and morphological abnormalities in aphids. These findings are discussed from the perspective of conservation biology.

  18. Modelling road accidents: An approach using structural time series

    Science.gov (United States)

    Junus, Noor Wahida Md; Ismail, Mohd Tahir

    2014-09-01

    In this paper, the trend of road accidents in Malaysia for the years 2001 until 2012 was modelled using a structural time series approach. The structural time series model was identified using a stepwise method, and the residuals for each model were tested. The best-fitted model was chosen based on the smallest Akaike Information Criterion (AIC) and prediction error variance. In order to check the quality of the model, a data validation procedure was performed by predicting the monthly number of road accidents for the year 2012. Results indicate that the best specification of the structural time series model to represent road accidents is the local level with a seasonal model.

  19. Radiological consequence assessments of degraded core accident scenarios derived from a generic Level 2 PSA of a BWR

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Toshimitsu; Ishikawa, Jun; Tomita, Kenichi; Muramatsu, Ken [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-12-01

    The radiological consequence assessments have been made of postulated core damage accidents with source terms derived from a generic Level 2 PSA of a BWR carried out by the Japan Atomic Energy Research Institute (JAERI). The source terms used were for the five core damage accident sequences with the drywell and wetwell failure cases, the release control case by venting of the containment and the accident termination case by the containment spray. The radiological consequences have been assessed for individual dose, collective dose, individual risk of early health effects and individual risk of late health effects by a probabilistic accident consequence assessment code, OSCAAR developed in JAERI. Following conclusions were obtained for the assumed source terms. In case of the over pressure failures of the primary containment vessel, the early fatalities can be mitigated through the implementation of early countermeasures, and the late cancer fatalities remains small. For the release control and accident termination cases, the individual and collective doses to the public can be reduced without any countermeasures due to the release reduction of the volatile radionuclides such as iodine and cesium. (author)

  20. Comparison of MACCS users calculations for the international comparison exercise on probabilistic accident consequence assessment code, October 1989--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Neymotin, L. [Brookhaven National Lab., Upton, NY (United States)

    1994-04-01

    Over the past several years, the OECD/NEA and CEC sponsored an international program intercomparing a group of six probabilistic consequence assessment (PCA) codes designed to simulate health and economic consequences of radioactive releases into atmosphere of radioactive materials following severe accidents at nuclear power plants (NPPs): ARANO (Finland), CONDOR (UK), COSYMA (CEC), LENA (Sweden), MACCS (USA), and OSCAAR (Japan). In parallel with this effort, two separate groups performed similar calculations using the MACCS and COSYMA codes. Results produced in the MACCS Users Group (Greece, Italy, Spain, and USA) calculations and their comparison are contained in the present report. Version 1.5.11.1 of the MACCS code was used for the calculations. Good agreement between the results produced in the four participating calculations has been reached, with the exception of the results related to the ingestion pathway dose predictions. The main reason for the scatter in those particular results is attributed to the lack of a straightforward implementation of the specifications for agricultural production and counter-measures criteria provided for the exercise. A significantly smaller scatter in predictions of other consequences was successfully explained by differences in meteorological files and weather sampling, grids, rain distance intervals, dispersion model options, and population distributions.

  1. Grey-Markov Model for Road Accidents Forecasting

    Institute of Scientific and Technical Information of China (English)

    李相勇; 严余松; 蒋葛夫

    2003-01-01

    In order to improve the forecasting precision of road accidents, by introducing Markov chains forecasting method, a grey-Markov model for forecasting road accidents is established based on grey forecasting method. The model combines the advantages of both grey forecasting method and Markov chains forecasting method, overcomes the influence of random fluctuation data on forecasting precision and widens the application scope of the grey forecasting. An application example is conducted to evaluate the grey-Markov model, which shows that the precision of the grey-Markov model is better than that of grey model in forecasting road accidents.

  2. Chernobyl Nuclear Reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  3. Applying Functional Modeling for Accident Management of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Morten; Zhang Xinxin [Harbin Engineering University, Harbin (China)

    2014-08-15

    The paper investigate applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow Modeling is given and a detailed presentation of the foundational means-end concepts is presented and the conditions for proper use in modelling accidents are identified. It is shown that Multilevel Flow Modeling can be used for modelling and reasoning about design basis accidents. Its possible role for information sharing and decision support in accidents beyond design basis is also indicated. A modelling example demonstrating the application of Multilevel Flow Modelling and reasoning for a PWR LOCA is presented.

  4. Fukushima accident: the consequences in Japan, France and in Japan; Accident de Fukushima: les repercusions au Japon, en France et dans le Japon

    Energy Technology Data Exchange (ETDEWEB)

    Foucher, N.; Sorin, F.

    2011-03-15

    This document begins with a description of the Fukushima accident, the second article reviews the main consequences in Japan of the accident: setting of a forbidden zone around the plant, restriction of the exports of food products, or the shutdown of the Hamaoka plant. The third article is the reporting of an interview of L. Oursel, deputy general director of the Areva group, this interview deals mainly with the safety standard of the EPR and with the issue of passive safety systems. The last part of the document is dedicated to the consequences in France (null sanitary impact, cooperation between Areva, EdF, CEA and the Japanese plant operator Tepco...) and in the rest of the world: the organization of resistance tests in the nuclear power plants operating in the European Union, the decision about the agreement of EPR and AP1000 reactor has been delayed in United-Kingdom, acceleration of the German program for abandoning nuclear energy, Italy suspends its nuclear program, China orders a general overhaul of the safety standard of its nuclear power plants, Poland and Romania reaffirm their trust in nuclear energy, France wishes a 'mechanism' allowing a quick international intervention in case of major nuclear accident, Russia proposes measures to improve nuclear safety. (A.C.)

  5. Consequences of the Chernobyl accident for the natural and human environments

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, M. [Lawrence Livermore National Lab., CA (United States); Aarkog, A. [Risoe National Lab., Roskilde (Denmark); Alexakhin, R. [Russian Inst. of Agricultural Radiology and Agroecology (Russian Federation); Anspaugh, L. [Lawrence Livermore National Lab., CA (United States); Arkhipov, N.P. [Scientific and Technical Centre of the RIA `Pripyat` (Ukraine); Johansson, K.-J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

    1996-07-01

    In the ten years since the Chernobyl accident, an enormous amount of work has been done to assess the consequences to the natural and human environment. Although it is difficult to summarize such a large and varied field, some general conclusions can be drawn. This background paper includes the main findings concerning the direct impacts of radiation on the flora and fauna; the general advances of knowledge in the cycling of radionuclides in natural, seminatural and agricultural environments; some evaluation of countermeasures that were used; and a summary of the human radiation doses resulting from the environmental contamination. although open questions still remain, it can be concluded that: (1) at high radiation levels, the natural environment has shown short term impacts but any significant long term impacts remain to be seen; (2) effective countermeasures can be taken to reduce the transfer of contamination from the environment to humans but these are highly site specific and must be evaluated in terms of practicality as well as population does reduction; (3) the majority of the doses have already been received by the human population. If agricultural countermeasures are appropriately taken, the main source of future doses will be the gathering of food and recreational activities in natural and seminatural ecosystems.

  6. Applying Functional Modeling for Accident Management of Nucler Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2014-01-01

    The paper investigates applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow...... for information sharing and decision support in accidents beyond design basis is also indicated. A modelling example demonstrating the application of Multilevel Flow Modelling and reasoning for a PWR LOCA is presented....

  7. Comparative modeling analyses of Cs-137 fate in the rivers impacted by Chernobyl and Fukushima accidents

    Energy Technology Data Exchange (ETDEWEB)

    Zheleznyak, M.; Kivva, S. [Institute of Environmental Radioactivity, Fukushima University (Japan)

    2014-07-01

    The consequences of two largest nuclear accidents of the last decades - at Chernobyl Nuclear Power Plant (ChNPP) (1986) and at Fukushima Daiichi NPP (FDNPP) (2011) clearly demonstrated that radioactive contamination of water bodies in vicinity of NPP and on the waterways from it, e.g., river- reservoir water after Chernobyl accident and rivers and coastal marine waters after Fukushima accident, in the both cases have been one of the main sources of the public concerns on the accident consequences. The higher weight of water contamination in public perception of the accidents consequences in comparison with the real fraction of doses via aquatic pathways in comparison with other dose components is a specificity of public perception of environmental contamination. This psychological phenomenon that was confirmed after these accidents provides supplementary arguments that the reliable simulation and prediction of the radionuclide dynamics in water and sediments is important part of the post-accidental radioecological research. The purpose of the research is to use the experience of the modeling activities f conducted for the past more than 25 years within the Chernobyl affected Pripyat River and Dnieper River watershed as also data of the new monitoring studies in Japan of Abukuma River (largest in the region - the watershed area is 5400 km{sup 2}), Kuchibuto River, Uta River, Niita River, Natsui River, Same River, as also of the studies on the specific of the 'water-sediment' {sup 137}Cs exchanges in this area to refine the 1-D model RIVTOX and 2-D model COASTOX for the increasing of the predictive power of the modeling technologies. The results of the modeling studies are applied for more accurate prediction of water/sediment radionuclide contamination of rivers and reservoirs in the Fukushima Prefecture and for the comparative analyses of the efficiency of the of the post -accidental measures to diminish the contamination of the water bodies. Document

  8. Applying Functional Modeling for Accident Management of Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2014-01-01

    The paper investigate applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow...

  9. ACCIDENT PREDICTION MODELS FOR UNSIGNALISED URBAN JUNCTIONS IN GHANA

    OpenAIRE

    Mohammed SALIFU, MSc., PhD, MIHT, MGhIE

    2004-01-01

    The main objective of this study was to provide an improved method for safety appraisal in Ghana through the development and application of suitable accident prediction models for unsignalised urban junctions. A case study was designed comprising 91 junctions selected from the two most cosmopolitan cities in Ghana. A wide range of traffic and road data together with the corresponding accident data for each junction for the three-year period 1996-1998 was utilized in the model development p...

  10. Traffic Accident, System Model and Cluster Analysis in GIS

    Directory of Open Access Journals (Sweden)

    Veronika Vlčková

    2015-07-01

    Full Text Available One of the many often frequented topics as normal journalism, so the professional public, is the problem of traffic accidents. This article illustrates the orientation of considerations to a less known context of accidents, with the help of constructive systems theory and its methods, cluster analysis and geoinformation engineering. Traffic accident is reframing the space-time, and therefore it can be to study with tools of technology of geographic information systems. The application of system approach enabling the formulation of the system model, grabbed by tools of geoinformation engineering and multicriterial and cluster analysis.

  11. Accidents - Chernobyl accident; Accidents - accident de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This file is devoted to the Chernobyl accident. It is divided in four parts. The first part concerns the accident itself and its technical management. The second part is relative to the radiation doses and the different contaminations. The third part reports the sanitary effects, the determinists ones and the stochastic ones. The fourth and last part relates the consequences for the other European countries with the case of France. Through the different parts a point is tackled with the measures taken after the accident by the other countries to manage an accident, the cooperation between the different countries and the groups of research and studies about the reactors safety, and also with the international medical cooperation, specially for the children, everything in relation with the Chernobyl accident. (N.C.)

  12. Effect of the Duration Time of a Nuclear Accident on Radiological Health Consequences

    Directory of Open Access Journals (Sweden)

    Hyojoon Jeong

    2014-03-01

    Full Text Available This study aimed to quantify the effect of duration time of a nuclear accident on the radiation dose of a densely populated area and the resulting acute health effects. In the case of nuclear accidents, the total emissions of radioactive materials can be classified into several categories. Therefore, the release information is very important for the assessment of risk to the public. We confirmed that when the duration time of the emissions are prolonged to 7 hours, the concentrations of radioactive substances in the ambient air are reduced by 50% compared to that when the duration time of emission is one hour. This means that the risk evaluation using only the first wind direction of an accident is very conservative, so it has to be used as a screening level for the risk assessment. Furthermore, it is judged that the proper control of the emission time of a nuclear accident can minimize the health effects on residents.

  13. RADIATION HYGIENIC CONSEQUENCES OF THE ACCIDENT AT THE CHERNOBYL NPP AND THE TASKS OF THEIR MINIMIZATION

    Directory of Open Access Journals (Sweden)

    G. G. Onischenko

    2009-01-01

    Full Text Available The paper presents data on the role and results of activities of Rospotrebnadzor bodies and institutions in the field of ensuring population radiation protection during various periods since accident at the Chernobyl NPP. Radiation hygienic characterization of territories affected by radioactive contamination from the accident, population exposure dose range, issues of ensuring radiological well-being of population and ways of their solution are being presented in the paper.

  14. BMX bicycles: accident comparison with other models.

    OpenAIRE

    1985-01-01

    A comparison has been made between BMX bicycle accidents and those occurring when children ride other types of bicycle. The injuries sustained are compared to see if the clinical impressions that BMX are more dangerous, and produce more facial injuries, are correct. This was found not to be true as half the children involved rode BMX bicycles, and the injuries sustained were similar to those occurring to non BMX riders. BMX riders had a lower proportion of serious injuries than riders of raci...

  15. INFLUENCE OF ANTIHYPERTENSIVE THERAPY ON PSYCHOLOGICAL STATUS OF CHERNOBYL NUCLEAR POWER PLANT ACCIDENT CONSEQUENCES LIQUIDATORS

    Directory of Open Access Journals (Sweden)

    E. M. Manoshkina

    2006-01-01

    Full Text Available Aim. To study psychological status and influence of antihypertensive therapy (AHT on it in Chernobyl nuclear power plant (NPP accident consequences liquidators, who suffer arterial hyper-tension (AH, with controlled treatment compared to the standard treatment in out-patient clinic. Material and methods. 81 liquidators with AH (all men were included into open compara-tive randomized study. Study duration was 12 months. Patients were randomized into main group (MG and control group (CG. Patients of MG received strictly regulated stepped AHT based on ACE inhibitor spirapril 6 mg daily (Quadropril®, Pliva-AVD, hypothiazide was added if necessary (12.5-25 mg daily and afterwards – atenolol (12.5-100 mg daily. In CG AHT and its correction was set by physician in polyclinic. Brief multifactor questionnaire for personality analysis was used to study psychological status. Results. 57 patients completed the study, 28 in MG and 29 in CG. In MG target blood pres-sure (BP levels were reached in 22 (78.6% patients, in CG – in 11 (38% patients (p<0.01. The main feature of psychological status of liquidators with AH was hypochondriac, depressive and anxious disorders. Controlled AHT made it possible to reach improvement in psychological status, i.e. growth of optimism and activity of patients, more often, than standard treatment in out-patient clinics. Increase in number of patients with pronounced anxious changes was observed in CG. Effi-ciency of AHT in liquidators with AH is connected with severity of depressive disturbances: in subgroups with inefficient treatment patients had the highest level of depression. In liquidators with AH, possessing neurotic disturbances, spirapril was efficient both as monotherapy, and in combina-tion with diuretic hydrochlorothiazide and beta-blocker atenolol. Conclusion. Controlled AHT in liquidators with AH has advantages over standard treatment in out-patient clinic and results in more frequent target BP level

  16. Estimation of the Radiological Consequences of Fukushima Dai-ichi Nuclear Power Plant Accident using MACCS2

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sora; Min, Byung-Il; Park, Kihyun; Yang, Byung-Mo; Suh, Kyung-suk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Three of them have undergone fuel melting and hydrogen explosions. A significant amount of radioactive material was released into the atmosphere from FDNPP and dispersed all over the world. In this study, we assessed the offsite consequences of Fukushima disaster in the region within a 30-km radius of FDNPP using the MELCOR Accident Consequence Code Systems 2(MACCS2) code, which is the Nuclear Regulatory Commission's (NRC's) code. The reflection of the realistic regional characteristics, such as long-term meteorological data, site- and population-specific data, and radiation safety regulatory, is essential to accurately analyze the off-site consequences. The assessment that reflects regional characteristics would contribute to identify main causes of exposure doses and to find the effective countermeasures for minimizing the accidental off-site consequences.

  17. Estimation of traffic accident costs: a prompted model.

    Science.gov (United States)

    Hejazi, Rokhshad; Shamsudin, Mad Nasir; Radam, Alias; Rahim, Khalid Abdul; Ibrahim, Zelina Zaitun; Yazdani, Saeed

    2013-01-01

    Traffic accidents are the reason for 25% of unnatural deaths in Iran. The main objective of this study is to find a simple model for the estimation of economic costs especially in Islamic countries (like Iran) in a straightforward manner. The model can show the magnitude of traffic accident costs with monetary equivalent. Data were collected from different sources that included traffic police records, insurance companies and hospitals. The conceptual framework, in our study, was based on the method of Ayati. He used this method for the estimation of economic costs in Iran. We promoted his method via minimum variables. Our final model has only three available variables which can be taken from insurance companies and police records. The running model showed that the traffic accident costs were US$2.2 million in 2007 for our case study route.

  18. Emergency Responses and Health Consequences after the Fukushima Accident; Evacuation and Relocation.

    Science.gov (United States)

    Hasegawa, A; Ohira, T; Maeda, M; Yasumura, S; Tanigawa, K

    2016-04-01

    The Fukushima accident was a compounding disaster following the strong earthquake and huge tsunami. The direct health effects of radiation were relatively well controlled considering the severity of the accident, not only among emergency workers but also residents. Other serious health issues include deaths during evacuation, collapse of the radiation emergency medical system, increased mortality among displaced elderly people and public healthcare issues in Fukushima residents. The Fukushima mental health and lifestyle survey disclosed that the Fukushima accident caused severe psychological distress in the residents from evacuation zones. In addition to psychiatric and mental health problems, there are lifestyle-related problems such as an increase proportion of those overweight, an increased prevalence of hypertension, diabetes mellitus and dyslipidaemia and changes in health-related behaviours among evacuees; all of which may lead to an increased cardiovascular disease risk in the future. The effects of a major nuclear accident on societies are diverse and enduring. The countermeasures should include disaster management, long-term general public health services, mental and psychological care, behavioural and societal support, in addition to efforts to mitigate the health effects attributable to radiation.

  19. A MELCOR model of Fukushima Daiichi Unit 3 accident

    Energy Technology Data Exchange (ETDEWEB)

    Sevón, Tuomo, E-mail: tuomo.sevon@vtt.fi

    2015-04-01

    Highlights: • A MELCOR model of the Fukushima Unit 3 accident was developed. • The MELCOR input file is published as electronic supplementary data with this paper. • Reactor pressure vessel lower head failed about 53 h after the earthquake. • 70% of fuel was discharged from reactor to containment. • 0.95% of cesium inventory was released to the environment. - Abstract: A MELCOR model of the Fukushima Daiichi Unit 3 accident was developed. The model is based on publicly available information, and the MELCOR input file is published as electronic supplementary data with this paper. According to the calculation, the reactor pressure vessel lower head failed about 53 h after the earthquake. At the end of the calculation, 30% of the fuel was still inside the reactor and 70% had been discharged to the containment. Almost all of the radioactive noble gases and 0.95% of the cesium inventory were released to the environment during the accident.

  20. Computational Modeling of Culture's Consequences

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, T.

    2010-01-01

    This paper presents an approach to formalize the influence of culture on the decision functions of agents in social simulations. The key components are (a) a definition of the domain of study in the form of a decision model, (b) knowledge acquisition based on a dimensional theory of culture, resulti

  1. Evaluation of sanitary consequences of Chernobylsk accident in France. Epidemiological surveillance plan, state of knowledge, risks evaluation and perspectives; Evaluation des consequences sanitaires de l'accident de Tchernobyl en France. Dispositif de surveillance epidemiologique, etat des connaissances, evaluation des risques et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Verger, P.; Cherie-Challine, L

    2000-12-15

    This report jointly written by IPSN and InVS, reviews the sanitary consequences in France of the Chernobyl accident, which occurred in 1986. The first point is dedicated to a short presentation of the knowledge relative to the sanitary consequences of the Chernobyl accident in the high contaminated countries and to the risk factors of the thyroid cancer. Secondly, this report describes the main systems of epidemiological surveillance of health implemented in France in 1986 and in 1999, as well as the data of the incidence and mortality of thyroid cancer observed in France since 1975. In addition, this report presents an analysis of the risk of thyroid cancer related to radioactive contamination in France, for young people of less than 15 years of age who where living in 1986 in the highest contaminated areas of France (Eastern territories). For this purpose, the theoretical number of thyroid cancers in excess is evaluated for this population, on the basis of different available risk model. Finally starting from the results of risk assessment, there is a discussion about the relevance and the feasibility of different epidemiological methods in view of answering the questions related to the sanitary consequences of the Chernobyl accident. In conclusion, this report recommends to reinforce the surveillance of thyroid cancer in France. (author)

  2. Quantifying safety benefit of winter road maintenance: accident frequency modeling.

    Science.gov (United States)

    Usman, Taimur; Fu, Liping; Miranda-Moreno, Luis F

    2010-11-01

    This research presents a modeling approach to investigate the association of the accident frequency during a snow storm event with road surface conditions, visibility and other influencing factors controlling for traffic exposure. The results have the premise to be applied for evaluating different maintenance strategies using safety as a performance measure. As part of this approach, this research introduces a road surface condition index as a surrogate measure of the commonly used friction measure to capture different road surface conditions. Data from various data sources, such as weather, road condition observations, traffic counts and accidents, are integrated and used to test three event-based models including the Negative Binomial model, the generalized NB model and the zero inflated NB model. These models are compared for their capability to explain differences in accident frequencies between individual snow storms. It was found that the generalized NB model best fits the data, and is most capable of capturing heterogeneity other than excess zeros. Among the main results, it was found that the road surface condition index was statistically significant influencing the accident occurrence. This research is the first showing the empirical relationship between safety and road surface conditions at a disaggregate level (event-based), making it feasible to quantify the safety benefits of alternative maintenance goals and methods.

  3. Bounding Radionuclide Inventory and Accident Consequence Calculation for the 1L Target

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, Charles T. IV [Los Alamos National Laboratory

    2011-01-01

    A bounding radionuclide inventory for the tungsten of the Los Alamos Neutron Science Center (LANSCE) IL Target is calculated. Based on the bounding inventory, the dose resulting from the maximum credible incident (MCI) is calculated for the maximally exposed offsite individual (MEOl). The design basis accident involves tungsten target oxidation following a loss of cooling accident. Also calculated for the bounding radionuclide inventory is the ratio to the LANSCE inventory threshold for purposes of inventory control as described in the target inventory control policy. A bounding radionuclide inventory calculation for the lL Target was completed using the MCNPX and CINDER'90 codes. Continuous beam delivery at 200 {micro}A to 2500 mA{center_dot}h was assumed. The total calculated activity following this irradiation period is 205,000 Ci. The dose to the MEOI from the MCI is 213 mrem for the bounding inventory. The LANSCE inventory control threshold ratio is 132.

  4. Pedal cycling accidents--mechanisms and consequences. A study from northern Sweden.

    Science.gov (United States)

    Björnstig, U; Näslund, K

    1984-01-01

    During one year, 447 persons attended the University Hospital of Umeå (Sweden) because of bicycling accidents. The incidence was highest in children, falling with advancing age. The most common accident was falling off a bicycle on an uneven or slippery road. Collisions and objects interfering with the rear or front wheel were also common causes. A high percentage of the injuries involved the head, and one-third of these were major injuries. Almost one-fifth of the injured received in-patient care (average 6 days) and a similar number were paid sickness benefit (average 26.5 days). Costs for treatment and benefit were estimated as approx. 2200 Swedish kronor (SEK) per injured person (1 USD = 4:30 SEK, 1979, and 1984 = 8:20 SEK).

  5. RESPONSIBILITY OF PHYSICAL EDUCATION TEACHER: CONSEQUENCES OF THE LEGAL CLAIMS IN ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Roberto Silva Piñeiro

    2015-12-01

    Full Text Available Being physical education an area that collects some case law, and that the professionalization required studies specifically, a review of appeals and complaints concerning accidents in school physical education, including sessions inside and outside. It was studied the sense of judicial and administrative resolutions about school accidents in physical education in Spain between 1988-2012, and its effects on physical education professionals. Most opinions and judgments studied the claims were rejected for various reasons, among them the casuality and risk taking, although there are outstanding judgments, blaming the teacher for not being present in class and for not preventing situations. The administration usually paid, although in some cases the teacher also participates.

  6. 液氨储罐泄露后果模拟及应急处置%Consequences Simulation and Emergency Disposal of Liquid Ammonia Tank Leakage Accidents

    Institute of Scientific and Technical Information of China (English)

    孙高穹; 刘剑俊

    2016-01-01

    Taking a liquid ammonia tank of a enterprise cold storage as an example,This paper identified the risk of ammonia storage possible poisoning and explosion accident,used the TNT equivalent method and overpressure criterion to simulate the accident consequences of the steam explosion caused by the leakage of a single tank,predicted the toxic gas leakage diffusion effect based on multi-puff model,Finally put forward prevention and emergency response measures of the liquid ammonia tank leak accident.%文章以某企业冷库配备的液氨储罐为实例,对液氨储存过程可能发生的中毒和爆炸事故进行风险识别,运用TNT当量法和超压准则模拟单个储罐泄露后引发蒸汽云爆炸的事故后果,同时运用多烟团模式预测有毒气体泄露扩散影响范围,最后提出液氨储罐泄露事故防范和应急处置措施。

  7. Modeling to assessment in an environmental consequences of nuclear accidents

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, A.N.; Meleshin, A.Yu.; Ponomarev, S.Yu; Ozornov, A.G.; Tepikin, V.E.; Arkhipov, N.P. [Chernobyl Scientific and Technical Centre for International Research, Chernobyl (Ukraine)

    2001-03-01

    To evaluate radiological risk of Chernobyl Exclusion Zone, radionuclide migration mechanisms were investigated including partially vertical migration through soil to plant. After collection and systematization of radiological data on {sup 90}Sr, {sup 137/134}Cs, Ce, and Ru regarding to terrestrial (spatial) and vertical distribution in soil profile in the framework of subproject-2 CheSCIR, the methodology of combining various radio-ecological and geographical information has been developed, which allows to analyze possible schemes of economic use of the contaminated territories. (S. Ohno)

  8. Statistical modelling of the frequency and severity of road accidents

    DEFF Research Database (Denmark)

    Janstrup, Kira Hyldekær

    of the reasons for heterogeneity has been made, which in the end may lead to devising policy measures (Paper 1). 3) A connection between the occurrence probability of trauma type and crash, vehicle and person characteristics exists (Paper 2). 4) The attitudes that accident reporting is useless are found...... the literature about under-reporting and gives new and innovative knowledge which can contribute to new policy measures for improving the reporting rate. For that reason this thesis should be used as an important tool whenever addressing the under-reporting challenge....... management tool.Initially models were built by using existing traffic accident data collected by the police and emergency rooms in Denmark. The data registered by the police was collected on traffic accidents occurred on Danish roads in the period between 2002 and 2008. The emergency room data were collected...

  9. Catastrophe model of the accident process, safety climate, and anxiety.

    Science.gov (United States)

    Guastello, Stephen J; Lynn, Mark

    2014-04-01

    This study aimed (a) to address the evidence for situational specificity in the connection between safety climate to occupational accidents, (b) to resolve similar issues between anxiety and accidents, (c) to expand and develop the concept of safety climate to include a wider range of organizational constructs, (d) to assess a cusp catastrophe model for occupational accidents where safety climate and anxiety are treated as bifurcation variables, and environ-mental hazards are asymmetry variables. Bifurcation, or trigger variables can have a positive or negative effect on outcomes, depending on the levels of asymmetry, or background variables. The participants were 1262 production employees of two steel manufacturing facilities who completed a survey that measured safety management, anxiety, subjective danger, dysregulation, stressors and hazards. Nonlinear regression analyses showed, for this industry, that the accident process was explained by a cusp catastrophe model in which safety management and anxiety were bifurcation variables, and hazards, age and experience were asymmetry variables. The accuracy of the cusp model (R2 = .72) exceeded that of the next best log-linear model (R2 = .08) composed from the same survey variables. The results are thought to generalize to any industry where serious injuries could occur, although situationally specific effects should be anticipated as well.

  10. Consequence Reasoning in Multilevel Flow Modelling

    DEFF Research Database (Denmark)

    Zhang, Xinxin; Lind, Morten; Ravn, Ole

    2013-01-01

    Consequence reasoning is a major element for operation support system to assess the plant situations. The purpose of this paper is to elaborate how Multilevel Flow Models can be used to reason about consequences of disturbances in complex engineering systems. MFM is a modelling methodology...... for representing process knowledge for complex systems. It represents the system by using means-end and part-whole decompositions, and describes not only the purposes and functions of the system but also the causal relations between them. Thus MFM is a tool for causal reasoning. The paper introduces MFM modelling...... syntax and gives detailed reasoning formulas for consequence reasoning. The reasoning formulas offers basis for developing rule-based system to perform consequence reasoning based on MFM, which can be used for alarm design, risk monitoring, and supervision and operation support system design....

  11. Neural Networks Based Modelling of Traffic Accidents in Interurban Rural Highways, Duzce Sampling

    Science.gov (United States)

    Ozgan, Ercan; Demirci, Recep

    this study, alternatively, Artificial Neural Network (ANN) based modelling of traffic accidents on two line interurban rural highways in terms of number of accidents; injuries and dead have been presented. This study was conducted for D100/11 state highway section in Duzce. In this section of the highway, totally 783 traffic accidents occurred and 1396 vehicles involved in these accidents between 2002 and 2006 years. Using traffic accident reports data, ANN was applied for modelling of traffic accidents with respect to distance and months. As a result, it was observed that there was a perfect fit between the simulation results and actual data of accidents and the created neural network model of accidents resembles the actual data. Therefore, the developed model could be an alternative method for predictions of traffic accidents on interurban rural highways.

  12. Managing Errors to Reduce Accidents in High Consequence Networked Information Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ganter, J.H.

    1999-02-01

    Computers have always helped to amplify and propagate errors made by people. The emergence of Networked Information Systems (NISs), which allow people and systems to quickly interact worldwide, has made understanding and minimizing human error more critical. This paper applies concepts from system safety to analyze how hazards (from hackers to power disruptions) penetrate NIS defenses (e.g., firewalls and operating systems) to cause accidents. Such events usually result from both active, easily identified failures and more subtle latent conditions that have resided in the system for long periods. Both active failures and latent conditions result from human errors. We classify these into several types (slips, lapses, mistakes, etc.) and provide NIS examples of how they occur. Next we examine error minimization throughout the NIS lifecycle, from design through operation to reengineering. At each stage, steps can be taken to minimize the occurrence and effects of human errors. These include defensive design philosophies, architectural patterns to guide developers, and collaborative design that incorporates operational experiences and surprises into design efforts. We conclude by looking at three aspects of NISs that will cause continuing challenges in error and accident management: immaturity of the industry, limited risk perception, and resource tradeoffs.

  13. Evaluating the consequences of loss of flow accident for a typical VVER-1000 nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mirvakili, S.M.; Safaei, S. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). Dept. of Nuclear Engineering, School of Mechanical Engineering; Faghihi, F. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). Safety Research Center

    2010-07-01

    The loss of coolant flow in a nuclear reactor can result from a mechanical or electrical failure of the coolant pump. If the reactor is not tripped promptly, the immediate effect is a rapid increase in coolant temperature, decrease in minimum departure from nucleate boiling ratio (DNBR) and fuel damage. This study evaluated the shaft seizure of a reactor coolant pump in a VVER-1000 nuclear reactor. The locked rotor results in rapid reduction of flow through the affected reactor coolant loop and in turn leads to an increase in the primary coolant temperature and pressure. The analysis was conducted with regard for superimposing loss of power to the power plant at the initial accident moment. The required transient functions of flow, pressure and power were obtained using system transient calculations applied in COBRA-EN computer code in order to calculate the overall core thermal-hydraulic parameters such as temperature, critical heat flux and DNBR. The study showed that the critical period for the locked rotor accident is the first few seconds during which the maximum values of pressure and temperature are reached. 10 refs., 1 tab., 3 figs.

  14. A Bayesian ensemble of sensitivity measures for severe accident modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hoseyni, Seyed Mohsen [Department of Basic Sciences, East Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Di Maio, Francesco, E-mail: francesco.dimaio@polimi.it [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Vagnoli, Matteo [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Zio, Enrico [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Chair on System Science and Energetic Challenge, Fondation EDF – Electricite de France Ecole Centrale, Paris, and Supelec, Paris (France); Pourgol-Mohammad, Mohammad [Department of Mechanical Engineering, Sahand University of Technology, Tabriz (Iran, Islamic Republic of)

    2015-12-15

    Highlights: • We propose a sensitivity analysis (SA) method based on a Bayesian updating scheme. • The Bayesian updating schemes adjourns an ensemble of sensitivity measures. • Bootstrap replicates of a severe accident code output are fed to the Bayesian scheme. • The MELCOR code simulates the fission products release of LOFT LP-FP-2 experiment. • Results are compared with those of traditional SA methods. - Abstract: In this work, a sensitivity analysis framework is presented to identify the relevant input variables of a severe accident code, based on an incremental Bayesian ensemble updating method. The proposed methodology entails: (i) the propagation of the uncertainty in the input variables through the severe accident code; (ii) the collection of bootstrap replicates of the input and output of limited number of simulations for building a set of finite mixture models (FMMs) for approximating the probability density function (pdf) of the severe accident code output of the replicates; (iii) for each FMM, the calculation of an ensemble of sensitivity measures (i.e., input saliency, Hellinger distance and Kullback–Leibler divergence) and the updating when a new piece of evidence arrives, by a Bayesian scheme, based on the Bradley–Terry model for ranking the most relevant input model variables. An application is given with respect to a limited number of simulations of a MELCOR severe accident model describing the fission products release in the LP-FP-2 experiment of the loss of fluid test (LOFT) facility, which is a scaled-down facility of a pressurized water reactor (PWR).

  15. Accident Prediction Models for Akure – Ondo Carriageway, Ondo ...

    African Journals Online (AJOL)

    FIRST LADY

    Accident data on the 52km Akure-Ondo Carriageway and Spot Speed data were collected ... fatal accident and 62% non-fatal accident, However, the regression analysis ... corresponding vehicle kilometre of travel, commerce, and transportation ... of accident can provide insight into the causes that contributed to accident.

  16. Calculation notes that support accident scenario and consequence of the evaporator dump

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, R.D., Westinghouse Hanford

    1996-09-09

    The purpose of this calculation note is to provide the basis for evaporator dump consequence for the Tank Farm Safety Analysis Report (FSAR). Evaporator Dump scenario is developed and details and description of the analysis methods are provided.

  17. The French-German initiative for Chernobyl: programme 3: Health consequences of the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Tirmarche, M. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Radiological Protection and Human Health Div. (DRPH), Radiobiology and Epidemiology Dept., 92 - Fontenay-aux-Roses (France); Kellerer, A.M. [Munchen Univ., Strahlenbiologisches Institut (Germany); Bazyka, D. [Chornobyl Center (CC), Kiev regoin (Ukraine)

    2006-07-01

    - Goals: The main objectives of the health programme are collection and validation of existing data on cancer and non cancer diseases in the most highly contaminated regions of Ukraine, Russia and Belarus, common scientific expertise on main health indicators and reliable dosimetry, and finally communication of the results to the scientific community and to the public. - General Tasks: 1- Comparison between high and low exposed regions, 2- Description of trends over time, 3- Consideration of specific age groups. This methodological approach is applied on Solid cancer incidence and leukaemia incidence in different regions in Ukraine, Belarus and Russia, With a special focus on thyroid cancer in young exposed ages. - Thyroid cancer: Those exposed in very young ages continue to express a relatively high excess of thyroid cancer even though they have now reached the age group 15-29. Those exposed as young adults show a small increase, at least partly due to better screening conditions - Leukemia: Description of leukemia trends for various age groups show no clear difference between exposed and unexposed regions when focusing on those exposed at very young ages. The rates of childhood leukemia before and after the accident show no evidence of any increase (oblasts in Belarus over 1982-1998). - Specific studies: Incidence of congenital malformations in Belarus; Infant mortality and morbidity in the most highly contaminated regions; Potential effects of prenatal irradiation on the brain as a result of the Chernobyl accident; Nutritional status of population living in regions with different levels of contamination; Dosimetry of Chernobyl clean-up workers; Radiological passports in contaminated settlements. - Congenital malformations: As a national register was existing since the 1980's and gives the possibility to compare trends before and after the accident, results of congenital malformations describe large results collected over Belarus, There is no evidence of a

  18. Probability and consequences of severe reactor accidents. 60th year atw

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Norman Carl [Massachusetts Institute of Technology (MIT), Cambridge, MA (United States). Dept. of Nuclear Engineering

    2015-06-15

    The study carried out on behalf of former USAEC (United States Atomic Energy Commission) led by Prof. Rasmussen and published in reworked form as WASH 1400 by the USNRC (United States Nuclear Regulatory Commission) in 1975, assessed in 3,300 pages the risks that can be deducted from severe accidents in nuclear power plants. The results, often quoted and criticised, were so far the most conclusive statements to this question. In his lecture at the reactor meeting in 1976, Prof. Rasmussen tried to trace back the conclusion of the results to the question: Is the use of larger nuclear power plants, in accordance to experiences and calculations so far, acceptable? His risk assessment, related to American power plants and cites, on behalf of the BMI is currently evaluated by the IRS together with the LRA on specific occurrences within the Federal Republic of Germany.

  19. Potential consequences in Norway after a hypothetical accident at Leningrad nuclear power plant. Potential release, fallout and predicted impacts on the environment

    Energy Technology Data Exchange (ETDEWEB)

    Nalbandyan, A.; Ytre-Eide, M.A.; Thoerring, H.; Liland, A.; Bartnicki, J.; Balonov, M.

    2012-06-15

    The report describes different hypothetical accident scenarios at the Leningrad nuclear power plant for both RBMK and VVER-1200 reactors. The estimated release is combined with different meteorological scenarios to predict possible fallout of radioactive substances in Norway. For a hypothetical catastrophic accident at an RBMK reactor combined with a meteorological worst case scenario, the consequences in Norway could be considerable. Foodstuffs in many regions would be contaminated above the food intervention levels for radioactive cesium in Norway. (Author)

  20. An application of probabilistic safety assessment methods to model aircraft systems and accidents

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guridi, G.; Hall, R.E.; Fullwood, R.R.

    1998-08-01

    A case study modeling the thrust reverser system (TRS) in the context of the fatal accident of a Boeing 767 is presented to illustrate the application of Probabilistic Safety Assessment methods. A simplified risk model consisting of an event tree with supporting fault trees was developed to represent the progression of the accident, taking into account the interaction between the TRS and the operating crew during the accident, and the findings of the accident investigation. A feasible sequence of events leading to the fatal accident was identified. Several insights about the TRS and the accident were obtained by applying PSA methods. Changes proposed for the TRS also are discussed.

  1. Boundary effects on car accidents in a cellular automaton model

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang; Zhao, Yue-Min

    2004-04-01

    In this paper we numerically study the probability Pac of occurrence of car accidents in the Nagel-Schreckenberg (NS) model with open boundary condition. In the deterministic NS model, numerical results show that there exists a critical value of extinction rate bgr above which no car accidents occur, and below which the probability Pac is independent of the speed limit vmax and the injection rate agr, but only determined by the extinction rate bgr. In the non-deterministic NS model, the probability Pac is a non-monotonic function of bgr in the region of low bgr value, while it is independent of bgr in the region of high bgr value. The stochastic braking not only reduces the occurrence of car accidents, but splits degenerate effects of vmax on the probability Pac. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the non-deterministic NS model with vmax = 1 in the case of low bgr value region. Qualitative differences between open and periodic systems in the relations of Pac to the bulk density rgr imply that various correlations may exist between the two systems.

  2. Boundary effects on car accidents in a cellular automaton model

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xianqing [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Ma Yuqiang [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Zhao Yuemin [School of Chemical Engineering and Technology, China University of Ming and Technology, Xuzhou 221008 (China)

    2004-04-30

    In this paper we numerically study the probability P{sub ac} of occurrence of car accidents in the Nagel-Schreckenberg (NS) model with open boundary condition. In the deterministic NS model, numerical results show that there exists a critical value of extinction rate {beta} above which no car accidents occur, and below which the probability P{sub ac} is independent of the speed limit v{sub max} and the injection rate {alpha}, but only determined by the extinction rate {beta}. In the non-deterministic NS model, the probability P{sub ac} is a non-monotonic function of {beta} in the region of low {beta} value, while it is independent of {beta} in the region of high {beta} value. The stochastic braking not only reduces the occurrence of car accidents, but splits degenerate effects of v{sub max} on the probability P{sub ac}. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the non-deterministic NS model with v{sub max} = 1 in the case of low {beta} value region. Qualitative differences between open and periodic systems in the relations of P{sub ac} to the bulk density {rho} imply that various correlations may exist between the two systems.

  3. Fault-tree Models of Accident Scenarios of RoPax Vessels

    Institute of Scientific and Technical Information of China (English)

    Pedro Ant(a)o; C. Guedes Soares

    2006-01-01

    Ro-Ro vessels for cargo and passengers (RoPax) are a relatively new concept that has proven to be popular in the Mediterranean region and is becoming more widespread in Northern Europe. Due to its design characteristics and amount of passengers, although less than a regular passenger liner, accidents with RoPax vessels have far reaching consequences both for economical and for human life. The objective of this paper is to identify hazards related to casualties of RoPax vessels. The terminal casualty events chosen are related to accident and incident statistics for this type of vessel. This paper focuses on the identification of the basic events that can lead to an accident and the performance requirements. The hazard identification is carried out as the first step of a Formal Safety Assessment (FSA) and the modelling of the relation between the relevant events is made using Fault Tree Analysis (FTA). The conclusions of this study are recommendations to the later steps of FSA rather than for decision making (Step 5 of FSA). These recommendations will be focused on the possible design shortcomings identified during the analysis by fault trees throughout cut sets. Also the role that human factors have is analysed through a sensitivity analysis where it is shown that their influence is higher for groundings and collisions where an increase of the initial probability leads to the change of almost 90% of the accident occurrence.

  4. Car Accidents in the Deterministic and Nondeterministic Nagel-Schreckenberg Models

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang

    In this paper, we study further the probability for the occurrence of car accidents in the Nagel-Schreckenberg model. By considering the braking probability, the conditions for car accidents to occur are modified to obtain accurate results. A universal phenomenological theory will also be presented to describe the probability for car accidents to occur in the deterministic and nondeterministic models, respectively.

  5. Radiological consequences of the Chernobyl reactor accident; Radiologische Folgen des Tschernobyl-Ungluecks

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, P.

    1996-05-01

    Large areas of Belarus, Russia, and the Ukraine have been highly contaminated by the radioactive fallout from the reactor accident at Chernobyl. The most affected areas are around Chernobyl and east of Gomel in Belarus, where part of the radioactive fallout came down with rain. The article maps the radioactive contamination through cesium 137 and iodine 131, and summarizes the immediate action taken at the time, as well as long-term remedial action for decontamination of soils. Data are given on the radiation exposure of the population, in particular doses to the thyroid, and prognoses on the incidence of thyroid cancer. (VHE) [Deutsch] Durch den Reaktorunfall von Tschernobyl wurden groessere Flaechen von Belarus, Russland und der Ukraine stark radioaktiv kontaminiert. Besonders betroffen sind die Umgebung von Tschernobyl sowie die Gegend oestlich von Gomel (Belarus), wo die radioaktive Wolke teilweise ausregnete. Der Artikel beschreibt die Belastung mit Caesium 137 und Iod 131 sowie die ergriffenen Sofortmassnahmen und die langfristigen Massnahmen zur Dekontamination der betroffenen Boeden. Die Strahlenbelastung der Bevoelkerung, v.a. die Schilddruesendosen, werden beschrieben, fuer Schilddruesenkrebs werden Prognosen gegeben. (VHE)

  6. Consequence analysis of core meltdown accidents in liquid metal fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suk, S.D.; Hahn, D. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2001-07-01

    Core disruptive accidents have been investigated at Korea Atomic Energy Research Institute(KAERI) as part of work to demonstrate the inherent and ultimate safety of the conceptual design of the Korea Advanced Liquid Metal Reactor(KALIMER), a 150 Mw pool-type sodium cooled prototype fast reactor that uses U-Pu-Zr metallic fuel. In this study, a simple method was developed using a modified Bethe-Tait method to simulate the kinetics and hydraulic behavior of a homogeneous spherical core over the period of the super-prompt critical power excursion induced by the ramp reactivity insertion. Calculations of energy release during excursions in the sodium-voided core of the KALIMER were subsequently performed using the method for various reactivity insertion rates up to 100 $/s, which has been widely considered to be the upper limit of ramp rates due to fuel compaction. Benchmark calculations were made to compare with the results of more detailed analysis for core meltdown energetics of the oxide fuelled fast reactor. A set of parametric studies was also performed to investigate the sensitivity of the results on the various thermodynamics and reactor parameters. (author)

  7. Current status and epidemiological research needs for achieving a better understanding of the consequences of the Chernobyl accident.

    Science.gov (United States)

    Cardis, Elisabeth

    2007-11-01

    Twenty years after the Chernobyl accident, there is no clearly demonstrated increase in the incidence of cancers in the most affected populations that can be attributed to radiation from the accident, except for the dramatic increase in thyroid cancer incidence among those exposed in childhood and adolescence. Increases in the incidence of cancers and other diseases have been reported in Belarus, the Russian Federation, and Ukraine, but much of the increase appears to be due to other factors, including improvements in diagnosis, reporting, and registration. Recent findings indicate a possible doubling of leukemia risk among Chernobyl liquidators and a small increase in the incidence of premenopausal breast cancer in the very most contaminated districts. Increased risks of cardiovascular diseases and cataracts have also been reported. These findings, however, need confirmation in well-designed analytical epidemiological studies with careful individual dose reconstruction. The absence of demonstrated increases in cancer risk--apart from thyroid cancer--is not the proof that no increase has in fact occurred. Based on the experience of atomic bomb survivors, and assuming that there is a linear, no-threshold dose-response relationship between exposure to ionizing radiation and the development of cancer in humans, a small increase in the relative risk of cancer is expected, even at the low to moderate doses received. Given the large number of individuals exposed, the absolute number of cancer cases caused could be substantial, particularly in the future. It is therefore essential to continue to use population registries to monitor trends in disease morbidity and mortality in the most contaminated areas, as well as among liquidators, in order to assess the public health impact of the accident. Studies of selected populations and diseases are also essential in order to study the real effect of the accident and compare it to predictions. Careful studies may in particular

  8. The Research Summary of UF6 Leakage Accident Consequence Assessment%UF6泄漏事故后果评价研究进展

    Institute of Scientific and Technical Information of China (English)

    陈海龙

    2013-01-01

    简要介绍了核燃料循环过程中UF6泄漏事故的几类事故情形,以及UF6泄漏后的大气扩散过程。目前,用于UF6泄漏事故后果评价的主要模型是HGSYSTEM/UF6模型和RASCAL模型:一般情况下,两种模型可溶性铀的平均浓度的预测值与实际测量值相比为小于2的数;在D类稳定下RASCAL预测的结果处于高斯模型和HGSYSTEM/UF6之间;而在F类稳定度下,1 km内基本上是RASCAL计算结果最低,1 km外3个模型预测结果无规律性。%This paper gathered and analyzed the scenarios for UF6 release accident ,and the atmosphere diffu-sion of UF6 and the air concentration of UF6 ,HF ,UO2 F2 .The result showed that two models are used to sim-ulate UF6 accidental release now , HGSYSTEM/UF6 model and RASCAL model . The former is a dense gas model ,and the latter is an accident consequence assessment model .The scholar of Portugal compared the two different dispersion models .The results showed that the calculated concentration by RASCAL model is between the HGSYSTEM/UF6 model and Gaussian plume model under the D stability ,but the tendency is complicated under the F stability .

  9. WHEN MODEL MEETS REALITY – A REVIEW OF SPAR LEVEL 2 MODEL AGAINST FUKUSHIMA ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    Zhegang Ma

    2013-09-01

    The Standardized Plant Analysis Risk (SPAR) models are a set of probabilistic risk assessment (PRA) models used by the Nuclear Regulatory Commission (NRC) to evaluate the risk of operations at U.S. nuclear power plants and provide inputs to risk informed regulatory process. A small number of SPAR Level 2 models have been developed mostly for feasibility study purpose. They extend the Level 1 models to include containment systems, group plant damage states, and model containment phenomenology and accident progression in containment event trees. A severe earthquake and tsunami hit the eastern coast of Japan in March 2011 and caused significant damages on the reactors in Fukushima Daiichi site. Station blackout (SBO), core damage, containment damage, hydrogen explosion, and intensive radioactivity release, which have been previous analyzed and assumed as postulated accident progression in PRA models, now occurred with various degrees in the multi-units Fukushima Daiichi site. This paper reviews and compares a typical BWR SPAR Level 2 model with the “real” accident progressions and sequences occurred in Fukushima Daiichi Units 1, 2, and 3. It shows that the SPAR Level 2 model is a robust PRA model that could very reasonably describe the accident progression for a real and complicated nuclear accident in the world. On the other hand, the comparison shows that the SPAR model could be enhanced by incorporating some accident characteristics for better representation of severe accident progression.

  10. RASCAL 及其在核事故后果评价中的应用%RASCAL and Its Application in Nuclear Accident Consequences Assessment

    Institute of Scientific and Technical Information of China (English)

    王韶伟; 侯杰; 陈海英; 曹亚丽; 乔清党; 李冰

    2014-01-01

    The development history, main function and basic principle used for emergency response of RAS-CAL, which is used for analyzing nuclear and radiate accident by American Nuclear Regulatory Commission, are presented in the study.The main modules/models are analyzed selectively, including source term to dose, field measurement to dose, meteorological data processor, source term calculation, transport, diffusion, and dose calculations.Then, RASCAL is applied to assess the radiological consequence of a nuclear power plant ac-cident emergency exercise.The assessment conclusion is displayed through Google Earth as 3D style.%介绍了美国核管会用于核与辐射事故后果分析的辐射评价系统( RASCAL)的主要功能和特性,重点分析了RASCAL的源项计算剂量模块、场外监测数据计算剂量模块、气象数据处理模块,以及源项计算模式、大气输运扩散模式和剂量计算模式。最后,将RASCAL应用于我国某核电厂事故应急演习中,评价分析事故情景下的放射性影响,并将其结果通过Google Earth进行三维展示。

  11. The reactor accident in Fukushima Daiichi. The consequence of design deficiencies and inadequate safety engineering; Der Reaktorunfall in Fukushima Daiichi. Folge fehlerhafter Auslegung und unzureichender Sicherheitstechnik

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-03-15

    The reactor accident in Fukushima Daiichi is discussed in the frame of design deficiencies and inadequate safety engineering. The progress of the accident as consequence of the earthquake and the tsunami is described. The radiological situation for the public is supposed to be blow the dose limit of 20 mSv/year. The WHO and UNSCEAR (United Nations Scientific Committee on the Effects of Atomic radiation) did not observe acute radiation injuries. The Japanese authorities have classified the accident to 7 of the INES scale. The German Atomforum e.V. considers the safety engineering of German NPPs to be superior to the Japanese situation due to higher emergency energy supply, extensive measures to reduce the hydrogen accumulation and mitigating measures for the accident management. German NPPS are considered highly robust as the EU stress tests have shown.

  12. Development and test results of the Realtime Severe Accident Model 5 (RSAM5) based on the MAAP5 For the Kori 1 simulator

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jin Hyuk; Lee, Myeong Soo [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The Real Time Severe Accident Model (RSAM) in the Kori simulator employs the standard MAAP 5.01.1101 code (which is defined as MAAP 5.01) plus several statically linked libraries that interface with the simulator environment. The physical phenomena that can be envisioned inside the reactor vessel, the reactor coolant system (RCS), and the containment during severe accidents are comprehensively modeled by the MAAP5 code. The MAAP5 code has been known to be a reliable tool for understanding the sequence of events that occur during severe LWR accidents, evaluating the consequences of the failure of emergency systems, assessing the effects of operator interventions, and investigating the influence of design features of the RCS, containment, and safety systems on the accident consequences. The purpose of this paper is to describe the modeling of the Kori Unit 1 nuclear plant with the MAAP5 code and major outputs in the event of the SBO, SBO + SGTR, SBO + LBLOCA.

  13. A Comparative analysis for control rod drop accident in RETRAN DNB and CETOP DNB Model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chang Keun; Kim, Yo Han; Ha, Sang Jun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    In Korea, the nuclear industries such as fuel manufacturer, the architect engineer and the utility, have been using the methodologies and codes of vendors, such as Westinghouse(WH), Combustion Engineering, for the safety analyses of nuclear power plants. Consequently the industries have kept up the many organizations to operate the methodologies and to maintain the codes for each vendor. It may occur difficulty to improve the safety analyses efficiency and technology related. So, the necessity another of methodologies and code systems applicable to Non- LOCA, beyond design basis accident and performance analyses for all types of pressurized water reactor(PWR) has been raised. Due to the above reason, the Korea Electric Power Research Institute(KEPRI) had decided to develop the new safety analysis code system for Korea Standard Nuclear Power Plants in Korea. As the first requirement, the best-estimate codes were required for applicable wider application area and realistic behavior prediction of power plants with various and sophisticated functions. After the investigation for few candidates, RETRAN-3D has been chosen as a system analysis code. As a part of the feasibility estimation for the methodology and code system, CRD(Control Rod Drop) accident which an event of Non-LOCA accidents for Uljin units 3 and 4 and Yonggwang 1 and 2 was selected to verify the feasibility of the methodology using the RETRAN-3D. In this paper, RETRAN DNB Model and CETOP DNB Model were analyzed by using comparative method.

  14. Car accidents in cellular automata models for one-lane traffic flow

    Science.gov (United States)

    Moussa, Najem

    2003-09-01

    Conditions for the occurrence of car accidents are introduced in the Nagel-Schreckenberg model. These conditions are based on the thought that a real accident depends on several parameters: an unexpected action of the car ahead (sudden stop or abrupt deceleration), the gap between the two cars, the velocity of the successor car and its delayed reaction time. We discuss then the effect of this delayed reaction time on the probability of traffic accidents. We find that these conditions for the occurrence of car accidents are necessary for modeling realistic accidents.

  15. A Bayesian hierarchical model for accident and injury surveillance.

    Science.gov (United States)

    MacNab, Ying C

    2003-01-01

    This article presents a recent study which applies Bayesian hierarchical methodology to model and analyse accident and injury surveillance data. A hierarchical Poisson random effects spatio-temporal model is introduced and an analysis of inter-regional variations and regional trends in hospitalisations due to motor vehicle accident injuries to boys aged 0-24 in the province of British Columbia, Canada, is presented. The objective of this article is to illustrate how the modelling technique can be implemented as part of an accident and injury surveillance and prevention system where transportation and/or health authorities may routinely examine accidents, injuries, and hospitalisations to target high-risk regions for prevention programs, to evaluate prevention strategies, and to assist in health planning and resource allocation. The innovation of the methodology is its ability to uncover and highlight important underlying structure of the data. Between 1987 and 1996, British Columbia hospital separation registry registered 10,599 motor vehicle traffic injury related hospitalisations among boys aged 0-24 who resided in British Columbia, of which majority (89%) of the injuries occurred to boys aged 15-24. The injuries were aggregated by three age groups (0-4, 5-14, and 15-24), 20 health regions (based of place-of-residence), and 10 calendar years (1987 to 1996) and the corresponding mid-year population estimates were used as 'at risk' population. An empirical Bayes inference technique using penalised quasi-likelihood estimation was implemented to model both rates and counts, with spline smoothing accommodating non-linear temporal effects. The results show that (a) crude rates and ratios at health region level are unstable, (b) the models with spline smoothing enable us to explore possible shapes of injury trends at both the provincial level and the regional level, and (c) the fitted models provide a wealth of information about the patterns (both over space and time

  16. Development and application of a random walk model of atmospheric diffusion in the emergency response of nuclear accidents

    Institute of Scientific and Technical Information of China (English)

    CHI Bing; LI Hong; FANG Dong

    2007-01-01

    Plume concentration prediction is one of the main contents of radioactive consequence assessment for early emergency response to nuclear accidents. Random characteristics of atmospheric diffusion itself was described, a random walk model of atmospheric diffusion (Random Walk) was introduced and compared with the Lagrangian puff model (RIMPUFF) in the nuclear emergency decision support system (RODOS) developed by the European Community for verification. The results show the concentrations calculated by the two models are quite close except that the plume area calculated by Random Walk is a little smaller than that by RIMPUFF. The random walk model for atmospheric diffusion can simulate the atmospheric diffusion in case of nuclear accidents, and provide more actual information for early emergency and consequence assessment as one of the atmospheric diffusion module of the nuclear emergency decision support system.

  17. Thermal-hydraulic modeling of reactivity accidents in MTR reactors

    Directory of Open Access Journals (Sweden)

    Khater Hany

    2006-01-01

    Full Text Available This paper describes the development of a dynamic model for the thermal-hydraulic analysis of MTR research reactors during a reactivity insertion accident. The model is formulated for coupling reactor kinetics with feedback reactivity and reactor core thermal-hydraulics. To represent the reactor core, two types of channels are considered, average and hot channels. The developed computer program is compiled and executed on a personal computer, using the FORTRAN language. The model is validated by safety-related benchmark calculations for MTR-TYPE reactors of IAEA 10 MW generic reactor for both slow and fast reactivity insertion transients. A good agreement is shown between the present model and the benchmark calculations. Then, the model is used for simulating the uncontrolled withdrawal of a control rod of an ETRR-2 reactor in transient with over power scram trip. The model results for ETRR-2 are analyzed and discussed.

  18. Reactor safety study. An assessment of accident risks in U. S. commercial nuclear power plants. Appendix XI. Analysis of comments on the draft WASH-1400 report. [PWR and BWR

    Energy Technology Data Exchange (ETDEWEB)

    1975-10-01

    Information is presented concerning comments on reactor safety by governmental agencies and civilian organizations; reactor safety study methodology; consequence model; probability of accident sequences; and various accident conditions.

  19. Review of psychological consequences of nuclear accidents and empirical study on peoples reactions to radiation protection activities in an imagined situation.; Katsaus ydinonnettomuuksien psykologisiin seurauksiin sekae empiirinen tutkimus saeteilysuojelutoimenpiteiden vaikutuksista kaeyttaeytymiseen kuvitteelisessa tilanteessa

    Energy Technology Data Exchange (ETDEWEB)

    Haukkala, A.; Eraenen, L. [Helsinki Univ. (Finland). Dept. of Social Psychology

    1994-10-01

    The report consist of two parts: a review of studies on psychological consequences of nuclear and radiation accidents in population and an empirical study of peoples reactions to protection actions in an event of hypothetical accident. Review is based on research results from two nuclear reactor accidents (Three Mile Island 1979, Chernobyl 1986) and a radiation accident in Goiania, Brazil 1987. (53 refs, 2 figs.,7 tabs.).

  20. Development of a post accident analysis model for KALIMER

    Energy Technology Data Exchange (ETDEWEB)

    Chang, W. P.; Ha, G. S.; Jeong, H. Y.; Kwon, Y. M.; Heo, S.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    An ultimate safety measure of the KALIMER depends on the inherent safety, which have the core maintain a negative reactivity during any accident periods. In order to secure the integrity of a fuel rod, the void reactivity feedback under sodium boiling must be analyzed. Even though the KALIMER design might not allow boiling at any circumstance, sodium boiling would be possible under HCDA (Hypothetical Core Disruptive Accident) initiating events which are represented by UTOP (Unprotected Transient Over Power), ULOF (Unprotected Loss Of Flow), ULOHS (Unprotected Loss Of Heat Sink), or sudden flow channel blockage, due to power excursion caused by the reactivity feedback. The slug and annular flow regimes tend to prevail for the boiling of a liquid-metal coolant such as sodium near the atmospheric pressure. In contrast, the bubbly flow is typical under a high pressure in light water reactors. This phenomenon difference brings to develop the present model, especially, at the onset of boiling. A few models had been developed for the sodium boiling analysis. The models such as those in the HOMSEP-2 and SAS series are classified into relatively detailed models. Both models are usually called a multiple-bubble slug ejection model. Some simpler models are also introduced to evade either parameter sensitivities or a mathematical complexity associated with those rigorous models. The present model based on the multiple-bubble slug ejection model. It allows a finite number (N) of bubbles, separated by liquid slugs, in a channel. Boiling occurs at a user specified superheat, and a generated vapor is modeled to fill the whole cross section of the coolant channel except for a static liquid film left on the cladding or/and structure surfaces. The model also assumes a vapor with one uniform pressure. The present analysis is focused on the behavior of early sodium boiling after ULOHS.

  1. Advanced accident sequence precursor analysis level 1 models

    Energy Technology Data Exchange (ETDEWEB)

    Sattison, M.B.; Thatcher, T.A.; Knudsen, J.K.; Schroeder, J.A.; Siu, N.O. [Idaho National Engineering Lab., Idaho National Lab., Idaho Falls, ID (United States)

    1996-03-01

    INEL has been involved in the development of plant-specific Accident Sequence Precursor (ASP) models for the past two years. These models were developed for use with the SAPHIRE suite of PRA computer codes. They contained event tree/linked fault tree Level 1 risk models for the following initiating events: general transient, loss-of-offsite-power, steam generator tube rupture, small loss-of-coolant-accident, and anticipated transient without scram. Early in 1995 the ASP models were revised based on review comments from the NRC and an independent peer review. These models were released as Revision 1. The Office of Nuclear Regulatory Research has sponsored several projects at the INEL this fiscal year to further enhance the capabilities of the ASP models. Revision 2 models incorporates more detailed plant information into the models concerning plant response to station blackout conditions, information on battery life, and other unique features gleaned from an Office of Nuclear Reactor Regulation quick review of the Individual Plant Examination submittals. These models are currently being delivered to the NRC as they are completed. A related project is a feasibility study and model development of low power/shutdown (LP/SD) and external event extensions to the ASP models. This project will establish criteria for selection of LP/SD and external initiator operational events for analysis within the ASP program. Prototype models for each pertinent initiating event (loss of shutdown cooling, loss of inventory control, fire, flood, seismic, etc.) will be developed. A third project concerns development of enhancements to SAPHIRE. In relation to the ASP program, a new SAPHIRE module, GEM, was developed as a specific user interface for performing ASP evaluations. This module greatly simplifies the analysis process for determining the conditional core damage probability for a given combination of initiating events and equipment failures or degradations.

  2. Global atmospheric dispersion modelling after the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Suh, K.S.; Youm, M.K.; Lee, B.G.; Min, B.I. [Korea Atomic Energy Research Institute (Korea, Republic of); Raul, P. [Universidad de Sevilla (Spain)

    2014-07-01

    A large amount of radioactive material was released to the atmosphere due to the Fukushima nuclear accident in March 2011. The radioactive materials released into the atmosphere were mostly transported to the Pacific Ocean, but some of them were fallen on the surface due to dry and wet depositions in the northwest area from the Fukushima nuclear site. Therefore, northwest part of the nuclear site was seriously contaminated and it was designated with the restricted zone within a radius of 20 ∼ 30 km around the Fukushima nuclear site. In the early phase of the accident from 11 March to 30 March, the radioactive materials were dispersed to an area of the inland and offshore of the nuclear site by the variations of the wind. After the Fukushima accident, the radionuclides were detected through the air monitoring in the many places over the world. The radioactive plume was transported to the east part off the site by the westerly jet stream. It had detected in the North America during March 17-21, in European countries during March 23-24, and in Asia during from March 24 to April 6, 2011. The radioactive materials were overall detected across the northern hemisphere passed by 15 ∼ 20 days after the accident. Three dimensional numerical model was applied to evaluate the dispersion characteristics of the radionuclides released into the air. Simulated results were compared with measurements in many places over the world. Comparative results had good agreements in some places, but they had a little differences in some locations. The difference between the calculations and measurements are due to the meteorological data and relatively coarse resolutions in the model. Some radioactive materials were measured in Philippines, Taiwan, Hon Kong and South Korea during from March 23-28. It inferred that it was directly transported from the Fukushima by the northeastern monsoon winds. This event was well represented in the numerical model. Generally, the simulations had a good

  3. Risk forecasting and evaluating model of Environmental pollution accident

    Institute of Scientific and Technical Information of China (English)

    ZENG Wei-hua; CHENG Sheng-tong

    2005-01-01

    Environmental risk (ER) fact ore come from ER source and they are controlled by the primary control mechanism (PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factore will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident(EPA) will break out; only the ER receptore are exposed in the ER field and damaged seriously,the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA. This model provides some scientific methods for risk evaluation, prevention and emergency response of EPA. This model not only enriches and develops the theory system of environment safety and emergency response, but also acts as an instruction for public safety, enterprise' s safety management and emergency response of the accident.

  4. ATMOSPHERIC MODELING IN SUPPORT OF A ROADWAY ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.

    2010-10-21

    The United States Forest Service-Savannah River (USFS) routinely performs prescribed fires at the Savannah River Site (SRS), a Department of Energy (DOE) facility located in southwest South Carolina. This facility covers {approx}800 square kilometers and is mainly wooded except for scattered industrial areas containing facilities used in managing nuclear materials for national defense and waste processing. Prescribed fires of forest undergrowth are necessary to reduce the risk of inadvertent wild fires which have the potential to destroy large areas and threaten nuclear facility operations. This paper discusses meteorological observations and numerical model simulations from a period in early 2002 of an incident involving an early-morning multicar accident caused by poor visibility along a major roadway on the northern border of the SRS. At the time of the accident, it was not clear if the limited visibility was due solely to fog or whether smoke from a prescribed burn conducted the previous day just to the northwest of the crash site had contributed to the visibility. Through use of available meteorological information and detailed modeling, it was determined that the primary reason for the low visibility on this night was fog induced by meteorological conditions.

  5. The Quota Simulation Analysis in Accident Consequence of Ethanol Tank Area%乙醇贮罐区事故后果定量模拟分析

    Institute of Scientific and Technical Information of China (English)

    苗金明; 刘倩倩; 张宪金

    2012-01-01

    This paper systematically analyzes the major risk of the ethanol tank area, and summarizes the possible consequences of the accident: tank poor fire, vapor cloud explosion (VCE), boiling liquid expanding vapor explosion (BLEVE). Also mathematical models of quan- titative simulation analysis and an applied methodology for simulating the consequences is presen- ted, which is conductive for overall layout of alcohol tank, security design, risk analysis, and accident prevention measures.%通过对乙醇罐区的危险特性进行分析,指出乙醇的事故后果主要为池火灾、蒸气云爆炸、沸腾液体扩展为蒸气爆炸;给出了乙醇事故后果的定量模拟分析的数学模型,同时进行了实例模拟,对指导乙醇贮罐区的总体布局、贮罐区安全设计、贮罐区危险性分析及事故预防措施均有一定参考价值。

  6. Analysis of traffic accident size for Korean highway using structural equation models.

    Science.gov (United States)

    Lee, Ju-Yeon; Chung, Jin-Hyuk; Son, Bongsoo

    2008-11-01

    Accident size can be expressed as the number of involved vehicles, the number of damaged vehicles, the number of deaths and/or the number of injured. Accident size is the one of the important indices to measure the level of safety of transportation facilities. Factors such as road geometric condition, driver characteristic and vehicle type may be related to traffic accident size. However, all these factors interact in complicate ways so that the interrelationships among the variables are not easily identified. A structural equation model is adopted to capture the complex relationships among variables because the model can handle complex relationships among endogenous and exogenous variables simultaneously and furthermore it can include latent variables in the model. In this study, we use 2649 accident data occurred on highways in Korea and estimate relationship among exogenous factors and traffic accident size. The model suggests that road factors, driver factors and environment factors are strongly related to the accident size.

  7. Development of a parametric containment event tree model for a severe BWR accident

    Energy Technology Data Exchange (ETDEWEB)

    Okkonen, T. [OTO-Consulting Ay, Helsinki (Finland)

    1995-04-01

    A containment event tree (CET) is built for analysis of severe accidents at the TVO boiling water reactor (BWR) units. Parametric models of severe accident progression and fission product behaviour are developed and integrated in order to construct a compact and self-contained Level 2 PSA model. The model can be easily updated to correspond to new research results. The analyses of the study are limited to severe accidents starting from full-power operation and leading to core melting, and are focused mainly on the use and effects of the dedicated severe accident management (SAM) systems. Severe accident progression from eight plant damage states (PDS), involving different pre-core-damage accident evolution, is examined, but the inclusion of their relative or absolute probabilities, by integration with Level 1, is deferred to integral safety assessments. (33 refs., 5 figs., 7 tabs.).

  8. A simplified model for calculating atmospheric radionuclide transport and early health effects from nuclear reactor accidents

    Energy Technology Data Exchange (ETDEWEB)

    Madni, I.K. [Brookhaven National Lab., Upton, NY (United States); Cazzoli, E.G.; Khatib-Rahbar, M. [Energy Research, Inc., Rockville, MD (United States)

    1995-11-01

    During certain hypothetical severe accidents in a nuclear power plant, radionuclides could be released to the environment as a plume. Prediction of the atmospheric dispersion and transport of these radionuclides is important for assessment of the risk to the public from such accidents. A simplified PC-based model was developed that predicts time-integrated air concentration of each radionuclide at any location from release as a function of time integrated source strength using the Gaussian plume model. The solution procedure involves direct analytic integration of air concentration equations over time and position, using simplified meteorology. The formulation allows for dry and wet deposition, radioactive decay and daughter buildup, reactor building wake effects, the inversion lid effect, plume rise due to buoyancy or momentum, release duration, and grass height. Based on air and ground concentrations of the radionuclides, the early dose to an individual is calculated via cloudshine, groundshine, and inhalation. The model also calculates early health effects based on the doses. This paper presents aspects of the model that would be of interest to the prediction of environmental flows and their public consequences.

  9. Administrative circular No.14 (Rev. 3) – Protection of members of the personnel against the financial consequences of illness, accident and incapacity for work

    CERN Multimedia

    2013-01-01

    Administrative Circular No. 14 (Rev. 3) entitled “Protection of members the personnel against the financial consequences of illness, accident and incapacity for work”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 19 April 2012 and entering into force on 1 January 2013, is available on the intranet site of the Human Resources Department.   This circular is applicable to all members of the personnel. It cancels and replaces Administrative Circular No. 14 (Rev. 2) entitled “Protection of members of the personnel against the financial consequences of illness, accident and disability” from July 2006. The circular was revised in order to improve the procedure before the Joint Advisory Rehabilitation and Disability Board (JARDB) and the management of long-term sick leave through a multidisciplinary approach launched upstream. The aim of this approach is to allow staff/fellows c...

  10. Study of the Severity of Accidents in Tehran Using Statistical Modeling and Data Mining Techniques

    Directory of Open Access Journals (Sweden)

    Hesamaldin Razi

    2013-01-01

    Full Text Available AbstractBackgrounds and Aims: The Tehran province was subject to the second highest incidence of fatalities due to traffic accidents in 1390. Most studies in this field examine rural traffic accidents, but this study is based on the use of logit models and artificial neural networks to evaluate the factors that affect the severity of accidents within the city of Tehran.Materials and Methods: Among the various types of crashes, head-on collisions are specified as the most serious type, which is investigated in this study with the use of Tehran’s accident data. In the modeling process, the severity of the accident is the dependent variable and defined as a binary covariate, which are non-injury accidents and injury accidents. The independent variables are parameters such as the characteristics of the driver, time of the accident, traffic and environmental characteristics. In addition to the prediction accuracy comparison of the two models, the elasticity of the logit model is compared with a sensitivity analysis of the neural network.Results: The results show that the proposed model provides a good estimate of an accident's severity. The explanatory variables that have been determined to be significant in the final models are the driver’s gender, age and education, along with negligence of the traffic rules, inappropriate acceleration, deviation to the left, type of vehicle, pavement conditions, time of the crash and street width.Conclusion: An artificial neural network model can be useful as a statistical model in the analysis of factors that affect the severity of accidents. According to the results, human errors and illiteracy of drivers increase the severity of crashes, and therefore, educating drivers is the main strategy that will reduce accident severity in Iran. Special attention should be given to a driver’s age group, with particular care taken when they are very young.

  11. Simulation on Poisson and negative binomial models of count road accident modeling

    Science.gov (United States)

    Sapuan, M. S.; Razali, A. M.; Zamzuri, Z. H.; Ibrahim, K.

    2016-11-01

    Accident count data have often been shown to have overdispersion. On the other hand, the data might contain zero count (excess zeros). The simulation study was conducted to create a scenarios which an accident happen in T-junction with the assumption the dependent variables of generated data follows certain distribution namely Poisson and negative binomial distribution with different sample size of n=30 to n=500. The study objective was accomplished by fitting Poisson regression, negative binomial regression and Hurdle negative binomial model to the simulated data. The model validation was compared and the simulation result shows for each different sample size, not all model fit the data nicely even though the data generated from its own distribution especially when the sample size is larger. Furthermore, the larger sample size indicates that more zeros accident count in the dataset.

  12. Radiative heat transfer modelling in a PWR severe accident sequence

    Energy Technology Data Exchange (ETDEWEB)

    Magali Zabiego; Florian Fichot [Institut de Radioprotection et de Surete Nucleaire - BP 3 - 13115 Saint-paul-Lez-Durance (France); Pablo Rubiolo [Westinghouse Science and Technology - 1344 Beulah Road - Pittsburgh - PA 15235 (United States)

    2005-07-01

    Full text of publication follows: The present study is devoted to the estimation of the radiative heat transfers during a severe accident sequence in a Pressurized Water Reactor. In such a situation, the residual nuclear power released by the fuel rods can not be evacuated and heats up the core. As a result, the cylindrical rods and the structures initially composing the core undergo a degradation process: swelling, breaking or melting of the rods and structures and eventual collapse to form a heap of fragments called a debris bed. As the solid matrix loses its original shape, the core geometry continuously evolves from standing, regularly-spaced cylinders to a non-homogeneous system including deformed remaining rods and structures and debris particles. To predict this type of sequence, the ICARE/CATHARE software [1] is developed by IRSN. Since the temperatures can reach values greater than 3000 K, it was of major interest to provide the code with an accurate radiative transfer model usable whatever the geometry of the system. Considering the size of a reactor core compared to the mean penetration length of radiation, the core can be seen as an optically thick medium. This observation led us to use the diffusion approximation to treat the radiation propagation. In this approach, the radiative flux is calculated in a way similar to thermal conduction: q{sub r} = [K{sub e}].{nabla}T where [K{sub e}] is the equivalent conductivity tensor of the system accounting for thermal and radiative transfer. An homogenization technique is applied to estimate the equivalent conductivity. Given the temperature level, the radiative contribution to the equivalent conductivity tensor quickly becomes dominant. This model was described earlier in [2] in which it was shown that an equivalent conductivity can be continuously calculated in the system when the geometry evolves from standing regular cylinder rods to swollen or broken ones, surrounded or not by a film of liquid materials, to

  13. 福岛核事故后果初步评价与思考%Consequences of the Fukushima Accident: A Preliminary Assessment and Discussion

    Institute of Scientific and Technical Information of China (English)

    张立国; 曹建主; 薛大知; 曲静原; 童节娟

    2012-01-01

    东日本的大地震引发的海啸造成日本福岛第一核电站发生严重核事故,引起了国内外社会广泛关注。对此次核事故放射性源项和事故所致后果进行了大致评价与预测。与后续事故发展情况相比较,本文评价工作从整体上把握了事故规模及其所致后果。%Tsunami due to the earthquake in East Japan Sea eventually leaded to a severe nuclear accident in Fukushima Dai-ichi nuclear power plant. This event immediately became the focus of the whole world. The work to roughly evaluate and predict the consequence of this nuclear accident is summarized in this paper and the work actually provides valuable information in predicting the scale and severity of the accident comparing to the published information on the accident thereafter.

  14. ASTEC V2 severe accident integral code: Fission product modelling and validation

    Energy Technology Data Exchange (ETDEWEB)

    Cantrel, L., E-mail: laurent.cantrel@irsn.fr; Cousin, F.; Bosland, L.; Chevalier-Jabet, K.; Marchetto, C.

    2014-06-01

    One main goal of the severe accident integral code ASTEC V2, jointly developed since almost more than 15 years by IRSN and GRS, is to simulate the overall behaviour of fission products (FP) in a damaged nuclear facility. ASTEC applications are source term determinations, level 2 Probabilistic Safety Assessment (PSA2) studies including the determination of uncertainties, accident management studies and physical analyses of FP experiments to improve the understanding of the phenomenology. ASTEC is a modular code and models of a part of the phenomenology are implemented in each module: the release of FPs and structural materials from degraded fuel in the ELSA module; the transport through the reactor coolant system approximated as a sequence of control volumes in the SOPHAEROS module; and the radiochemistry inside the containment nuclear building in the IODE module. Three other modules, CPA, ISODOP and DOSE, allow respectively computing the deposition rate of aerosols inside the containment, the activities of the isotopes as a function of time, and the gaseous dose rate which is needed to model radiochemistry in the gaseous phase. In ELSA, release models are semi-mechanistic and have been validated for a wide range of experimental data, and noticeably for VERCORS experiments. For SOPHAEROS, the models can be divided into two parts: vapour phase phenomena and aerosol phase phenomena. For IODE, iodine and ruthenium chemistry are modelled based on a semi-mechanistic approach, these FPs can form some volatile species and are particularly important in terms of potential radiological consequences. The models in these 3 modules are based on a wide experimental database, resulting for a large part from international programmes, and they are considered at the state of the art of the R and D knowledge. This paper illustrates some FPs modelling capabilities of ASTEC and computed values are compared to some experimental results, which are parts of the validation matrix.

  15. Modelling transport and deposition of caesium and iodine from the Chernobyl accident using the DREAM model

    Directory of Open Access Journals (Sweden)

    J. Brandt

    2002-06-01

    Full Text Available A tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model, has been developed for modelling transport, dispersion and deposition (wet and dry of radioactive material from accidental releases, as the Chernobyl accident. The model is a combination of a Lagrangian model, that includes the near source dispersion, and an Eulerian model describing the long-range transport. The performance of the transport model has previously been tested within the European Tracer Experiment, ETEX, which included transport and dispersion of an inert, non-depositing tracer from a controlled release. The focus of this paper is the model performance with respect to the deposition of 137Cs, 134Cs and 131I from the Chernobyl accident, using different relatively simple and comprehensive parameterizations. The performance, compared to measurements, of different combinations of parameterizations of wet and dry deposition schemes has been evaluated, using different statistical tests.

  16. IRSN press briefing on the issue 'Fukushima, one year after': Situation of Fukushima Dai-ichi nuclear installations; Accident of the Fukushima Dai-ichi: briefing on the situation in February 2012; The Fukushima 1 accident one year after: assessment of environmental consequences in Japan; assessment of consequences of the Fukushima accident on the environment in Japan, one year after; Health consequences of the Fukushima Dai-ichi: situation briefing in February 2012; Point presse de l'IRSN sur le theme 'Fukushima, un an apres': Situation des installations nucleaires de Fukushima Dai-ichi; Accident survenu a la centrale de Fukushima Dai-Ichi Point de la situation en fevrier 2012; L'accident de Fukushima 1 an apres: bilan des consequences environnementales au Japon; bilan des consequences de l'accident de Fukushima sur l'environnement au Japon, un an apres l'accident; Les consequences sanitaires de l'accident de Fukushima Dai-ichi: point de situation en fevrier 2012

    Energy Technology Data Exchange (ETDEWEB)

    Charles, T.; Jourdain, Jean-Rene

    2012-02-28

    This document gathers reports and Power Point presentations (with maps, data tables and graphs) dealing with the Fukushima accident, one year after its occurrence. Different issues are addressed: the status of the nuclear installations, the situation of the installations and of the environment, assessments, measurements and investigations on the effects and consequences of the accident (radioactive releases and fallouts) on the ground and marine environment and on public health

  17. Logit Model of Motorcycle Accidents in the Philippines Considering Personal and Environmental Factors

    Directory of Open Access Journals (Sweden)

    Rosemary R. Seva

    2013-06-01

    Full Text Available The study aims to determine significant personal and environmental variables in predicting motorcycle accidents in the Philippines, compare the results with findings in other countries, and propose possible government interventions. Data were gathered from 177 participants through the use of a survey in a licensing center in the largest city in Metro Manila. Logistic regression was used to predict the likelihood of an accident from variables considered in the model. Three variables were found to be significant predictors of motorcycle accidents: age, driving behavior, and junction type. Younger drivers are more likely to be involved in accidents. The significance of age was unexpected because similar models found this to be insignificant. Driving behavior, specifically, committing violation predicts accident likelihood. Driving at t- and y-junctions also predicts motorcycle accidents. In the Philippines, a unique set of variables were found to predict motorcycle accidents. Although previous studies have established the effect of these variables to accident likelihood, the combination was unforeseen. Government agencies can focus on interventions directed at these three variables.

  18. Self Rescue Model-SeReMo-A model to determine the effects of human behaviour and safety measures on the consequences of a hazardous material release-development of the new triage injury model and self-rescue for fire and explosion accidents

    NARCIS (Netherlands)

    Trijssenaar, I.J.M.; Horst, M.J. van der; Simons, M.; Sterkenburg, R.P.

    2014-01-01

    Human behaviour during a large-scale hazardous material release can make the difference between life, serious injury and death. People may decide to investigate what is going on or to take shelter, while a toxic or flammable cloud is being released. The Self Rescue Model (SeReMo) has been developed

  19. Predictive model for motorcycle accidents at three-legged priority junctions.

    Science.gov (United States)

    Harnen, S; Umar, R S Radin; Wong, S V; Wan Hashim, W I

    2003-12-01

    In conjunction with a nationwide motorcycle safety program, the provision of exclusive motorcycle lanes has been implemented to overcome link-motorcycle accidents along trunk roads in Malaysia. However, not much work has been done to address accidents at junctions involving motorcycles. This article presents the development of predictive model for motorcycle accidents at three-legged major-minor priority junctions of urban roads in Malaysia. The generalized linear modeling technique was used to develop the model. The final model reveals that motorcycle accidents are proportional to the power of traffic flow. An increase in nonmotorcycle and motorcycle flows entering the junctions is associated with an increase in motorcycle accidents. Nonmotorcycle flow on major roads had the highest effect on the probability of motorcycle accidents. Approach speed, lane width, number of lanes, shoulder width, and land use were found to be significant in explaining motorcycle accidents at the three-legged major-minor priority junctions. These findings should enable traffic engineers to specifically design appropriate junction treatment criteria for nonexclusive motorcycle lane facilities.

  20. Long-term therapy for polymorphic mental disorders in liquidators of the consequences of the accident at the Chernobyl nuclear power plant

    Directory of Open Access Journals (Sweden)

    V. N. Krasnov

    2012-01-01

    Full Text Available The paper gives the results of a long-term comparative therapeutic study of a large cohort of more than 500 liquidators of the consequences of the accident at the Chernobyl nuclear power plant in 1986. The patients were followed up (and periodically treated at hospital 5 years or more, usually 10—15 years. The study confirmed mainly the cerebrovascular nature of disorders following the pattern seen in moderate psychoorganic syndrome. Therapy with cerebroprotective agents having vascular vegetotropic properties could yield certain therapeutic results and, to some extent, preserve social functioning capacity in these patients.

  1. Updated action plan for the implementation of measures as a consequence of the Fukushima reactor accident; Fortgeschriebener Aktionsplan zur Umsetzung von Massnahmen nach dem Reaktorunfall in Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-03-15

    The updated German action plan for the implementation of measures as a consequence of the Fukushima reactor accident covers the following issues: decision on the future utilization of nuclear energy in Germany; national frame for security checks, inspections and measures for nuclear power plants; international frame for inspections; action plan and WENRA reference level; action plan for the implementation of measures form robustness enhancement in German nuclear power plants (SNC topics 1-3), action plan for implementation of further measures (CNS topics 4-6).

  2. An Artificial Neural Network Model for Highway Accident Prediction: A Case Study of Erzurum, Turkey

    Directory of Open Access Journals (Sweden)

    Muhammed Yasin Çodur

    2015-06-01

    Full Text Available This study presents an accident prediction model of Erzurum’s Highways in Turkey using artificial neural network (ANN approaches. There are many ANN models for predicting the number of accidents on highways that were developed using 8 years with 7,780 complete accident reports of historical data (2005-2012. The best ANN model was chosen for this task and the model parameters included years, highway sections, section length (km, annual average daily traffic (AADT, the degree of horizontal curvature, the degree of vertical curvature, traffic accidents with heavy vehicles (percentage, and traffic accidents that occurred in summer (percentage. In the ANN model development, the sigmoid activation function was employed with Levenberg-Marquardt algorithm. The performance of the developed ANN model was evaluated by mean square error (MSE, the root mean square error (RMSE, and the coefficient of determination (R2. The model results indicate that the degree of vertical curvature is the most important parameter that affects the number of accidents on highways.

  3. Consequences of Fukushima 11032011 - Radiological consequences from the nuclear accidents in Fukushima on 11 March 2011; Fukushima Auswirkung 11032011 -- Radiologische Auswirkungen aus den kerntechnischen Unfaellen in Fukushima vom 11.03.2011

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-12-15

    On 11 March 2011 at 14.46 the strongest earthquake ever recorded in Japan struck the Pacific coast in front of Fukushima. The earthquake and the following tsunami damaged the nuclear power plants in Fukushima Dai-ichi to such an extent that the Japanese government declared the state of catastrophic accident with degree 7 according to the International Nuclear and Radiological Event Scale (INES). At Fukushima Dai-ichi there were 6 boiling water reactors (BWR), a storage pool for spent fuel assemblies and a dry cask storage. 12 km apart at Fukushima Dai-ni there were 4 more BWR. At the moment of the earthquake the reactors 1 to 3 of Fukushima Dai-ichi, as well as the 4 reactors at Fukushima Dai-ni, were at full power, while the reactors 4 to 6 of Fukushima Dai-ichi were shut down for revision. From 12 March 2011 on, fairly large quantities of radioactive materials were released from Fukushima Dai-ichi reactors with meaningful consequences on the population in the near neighbourhood. The irradiation from the radioactivity bearing clouds, the ingestion and inhalation, and the deposit of radioactive materials on the ground threatened the population. The inhabitants of large areas had to be evacuated. Furthermore, radioactive materials contaminated the drinking water, the sea water and finally the plants and animals, i.e. the food chain of the people living there. The Swiss Federal Nuclear Safety Inspectorate (ENSI) continuously proceeded with the evaluation of the situation in Japan and a specialists' team made a detailed analysis of the accident, with emphasis on the human and organisational factors and on the lessons learned from this. The present report describes the present knowledge about the radiological consequences of the accident in Fukushima Dai-ichi on the population in the neighbourhood and on the staff at the power plant, until October 2011. First, the unrolling of the accident and its consequences on the plant site are analysed according to

  4. Contribution to Accident Prediction Models Development for Rural Two-Lane Roads in Serbia

    Directory of Open Access Journals (Sweden)

    Draženko Glavić

    2016-08-01

    Full Text Available Over the last three decades numerous research efforts have been conducted worldwide to determine the relationship between traffic accidents and traffic and road characteristics. So far, the mentioned studies have not been carried out in Serbia and in the region. This paper represents one of the first attempts to develop accident prediction models in Serbia. The paper provides a comprehensive literature review, describes procedures for collection and analysis of the traffic accident data, as well as the methodology used to develop the accident prediction models. The paper presents models obtained by both univariate and multivariate regression analyses. The obtained results are compared to the results of other studies and comparisons are discussed. Finally, the paper presents conclusions and important points for future research. The results of this research can find theoretical as well as practical application.

  5. Speed Spatial Distribution Models for Traffic Accident Section of Freeway Based on Computer Simulation

    Institute of Scientific and Technical Information of China (English)

    Decai Li; Jiangwei Chu; Wenhui Zhang; Xiaojuan Wang; Guosheng Zhang

    2015-01-01

    Simulation models for accident section on freeway are built in microscopic traffic flow simulation environment. In these models involving 2⁃lane, 3⁃lane and 4⁃lane freeway, one detector is set every 10 m to measure section running speed. According to the simulation results, speed spatial distribution curves for traffic accident section on freeway are drawn which help to determine dangerous sections on upstream of accident section. Furthermore, the speed spatial distribution models are obtained for every speed distribution curve. The results provide theoretical basis for determination on temporal and spatial influence ranges of traffic accident and offer reference to formulation of speed limit scheme and other management measures.

  6. TIRE MODELS USED IN VEHICLE DYNAMIC APPLICATIONS AND THEIR USING IN VEHICLE ACCIDENT SIMULATIONS

    Directory of Open Access Journals (Sweden)

    Osman ELDOĞAN

    1995-01-01

    Full Text Available Wheel model is very important in vehicle modelling, it is because the contact between vehicle and road is achieved by wheel. Vehicle models can be dynamic models which are used in vehicle design, they can also be models used in accident simulations. Because of the importance of subject, many studies including theoretical, experimental and mixed type have been carried out. In this study, information is given about development of wheel modelling and research studies and also use of these modellings in traffic accident simulations.

  7. Cellular automata model simulating traffic car accidents in the on-ramp system

    Science.gov (United States)

    Echab, H.; Lakouari, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2015-01-01

    In this paper, using Nagel-Schreckenberg model we study the on-ramp system under the expanded open boundary condition. The phase diagram of the two-lane on-ramp system is computed. It is found that the expanded left boundary insertion strategy enhances the flow in the on-ramp lane. Furthermore, we have studied the probability of the occurrence of car accidents. We distinguish two types of car accidents: the accident at the on-ramp site (Prc) and the rear-end accident in the main road (Pac). It is shown that car accidents at the on-ramp site are more likely to occur when traffic is free on road A. However, the rear-end accidents begin to occur above a critical injecting rate αc1. The influence of the on-ramp length (LB) and position (xC0) on the car accidents probabilities is studied. We found that large LB or xC0 causes an important decrease of the probability Prc. However, only large xC0 provokes an increase of the probability Pac. The effect of the stochastic randomization is also computed.

  8. A Quasi-Poisson Approach on Modeling Accident Hazard Index for Urban Road Segments

    Directory of Open Access Journals (Sweden)

    Lu Ma

    2014-01-01

    Full Text Available In light of the recently emphasized studies on risk evaluation of crashes, accident counts under specific transportation facilities are adopted to reflect the chance of crash occurrence. The current study introduces more comprehensive measure with the supplement information of accidental harmfulness into the expression of accident risks which are also named Accident Hazard Index (AHI in the following context. Before the statistical analysis, datasets from various sources are integrated under a GIS platform and the corresponding procedures are presented as an illustrated example for similar analysis. Then, a quasi-Poisson regression model is suggested for analyses and the results show that the model is appropriate for dealing with overdispersed count data and several key explanatory variables were found to have significant impact on the estimation of AHI. In addition, the effect of weight on different severity levels of accidents is examined and the selection of the weight is also discussed.

  9. Antecedents and Consequences of Business Model Innovation

    DEFF Research Database (Denmark)

    Waldner, Florian; Poetz, Marion; Grimpe, Christoph

    2015-01-01

    evidence seems to be confined to firm-level antecedents and pays little attention to the impact of industry structure. This study investigates how different stages of an industry’s life cycle and levels of industry competition affect firms’ business model innovation, and how such innovation translates...... performance. Our findings contribute to the ongoing dialog on the role of industry structure in business model innovation, and provide implications for the management of business model innovation.......What makes firms innovate their business models? Why do they engage in innovating how they create, deliver, and capture value? And how does such innovation translate into innovation performance? Despite the importance of business model innovation for achieving competitive advantage, existing...

  10. Surety of human elements of high consequence systems: An organic model

    Energy Technology Data Exchange (ETDEWEB)

    FORSYTHE,JAMES C.; WENNER,CAREN A.

    2000-04-25

    Despite extensive safety analysis and application of safety measures, there is a frequent lament, ``Why do we continue to have accidents?'' Two breakdowns are prevalent in risk management and prevention. First, accidents result from human actions that engineers, analysts and management never envisioned and second, controls, intended to preclude/mitigate accident sequences, prove inadequate. This paper addresses the first breakdown, the inability to anticipate scenarios involving human action/inaction. The failure of controls has been addressed in a previous publication (Forsythe and Grose, 1998). Specifically, this paper presents an approach referred to as surety. The objective of this approach is to provide high levels of assurance in situations where potential system failure paths cannot be fully characterized. With regard to human elements of complex systems, traditional approaches to human reliability are not sufficient to attain surety. Consequently, an Organic Model has been developed to account for the organic properties exhibited by engineered systems that result from human involvement in those systems.

  11. Restructuring of an Event Tree for a Loss of Coolant Accident in a PSA model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ho-Gon; Han, Sang-Hoon; Park, Jin-Hee; Jang, Seong-Chul [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    Conventional risk model using PSA (probabilistic Safety Assessment) for a NPP considers two types of accident initiators for internal events, LOCA (Loss of Coolant Accident) and transient event such as Loss of electric power, Loss of cooling, and so on. Traditionally, a LOCA is divided into three initiating event (IE) categories depending on the break size, small, medium, and large LOCA. In each IE group, safety functions or systems modeled in the accident sequences are considered to be applicable regardless of the break size. However, since the safety system or functions are not designed based on a break size, there exist lots of mismatch between safety system/function and an IE, which may make the risk model conservative or in some case optimistic. Present paper proposes new methodology for accident sequence analysis for LOCA. We suggest an integrated single ET construction for LOCA by incorporating a safety system/function and its applicable break spectrum into the ET. Integrated accident sequence analysis in terms of ET for LOCA was proposed in the present paper. Safety function/system can be properly assigned if its applicable range is given by break set point. Also, using simple Boolean algebra with the subset of the break spectrum, final accident sequences are expressed properly in terms of the Boolean multiplication, the occurrence frequency and the success/failure of safety system. The accident sequence results show that the accident sequence is described more detailed compared with the conventional results. Unfortunately, the quantitative results in terms of MCS (minimal Cut-Set) was not given because system fault tree was not constructed for this analysis and the break set points for all 7 point were not given as a specified numerical quantity. Further study may be needed to fix the break set point and to develop system fault tree.

  12. 某涉氨制冷企业液氨储罐泄漏事故的后果分析%Analysis of An Ammonia Refrigeration Enterprise Involved in Liquid Ammonia Storage Tank Leakage Accident Consequence

    Institute of Scientific and Technical Information of China (English)

    周峰

    2014-01-01

    以某涉氨制冷企业液氨储罐为例,选用蒸气云爆炸、沸腾液体扩展蒸气爆炸和中毒模型对液氨储罐泄漏事故进行后果分析,定量地得出各类伤害半径,为企业制定应急救援预案和政府进行安全监管提供科学依据。%Taking the liquid ammonia tank of a refrigeration enterprise as example, the consequences of liquid ammonia storage tank leakage accident were analyzed using vapor cloud explosion model, boiling liq-uid expanding vapor explosion model and poisoning model. The various damage radiuses were calculated. It provided the scientific basis for enterprises to formulate emergency rescue plans and for safety supervision of government.

  13. A GIS-based prediction and assessment system of off-site accident consequence for Guangdong nuclear power plant.

    Science.gov (United States)

    Wang, X Y; Qu, J Y; Shi, Z Q; Ling, Y S

    2003-01-01

    GNARD (Guangdong Nuclear Accident Real-time Decision support system) is a decision support system for off-site emergency management in the event of an accidental release from the nuclear power plants located in Guangdong province, China. The system is capable of calculating wind field, concentrations of radionuclide in environmental media and radiation doses. It can also estimate the size of the area where protective actions should be taken and provide other information about population distribution and emergency facilities available in the area. Furthermore, the system can simulate and evaluate the effectiveness of countermeasures assumed and calculate averted doses by protective actions. All of the results can be shown and analysed on the platform of a geographical information system (GIS).

  14. Modeling the Consequences of Proterozoic Oxygenation

    Science.gov (United States)

    Bachan, A.; Kump, L. R.

    2013-12-01

    Abundant geologic data indicate an increase in atmospheric O2 levels starting at 2.4 Ga. Associated with this increase is a protracted interval of elevated δ13C known as the Lomagundi event. The elevated δ13C values have long been taken as evidence for elevated levels of organic carbon burial driving O2 production and oxygenation. Yet recently published data indicate that the increase in pO2, (as signaled by the disappearance of the MIF signature) occurs immediately below sediments with enriched δ13C values, in contrast to the expected order of events if organic carbon burial was the cause of O2 accumulation. A way to resolve this conundrum is if an initial rise in pO2 above the MIF threshold resulted in a positive feedback that led to enhanced Corg burial and a further increase in pO2. Here we utilize a numerical box model to explore the hypothesis that increased oxygenation (most likely via reduced O2 consumption) was the driver of elevated organic carbon burial, as manifested in enriched δ13C values. The numerical model contains boxes representing sedimentary and oceanic reservoirs, and tracks the fluxes and isotopic compositions of carbon, calcium, sulfate, and phosphate, as well as ocean chemistry parameters including pCO2, pH, and calcite saturation. We find that perturbing the model from a postulated Archean steady state with a step function in O2 input gives rise to a major increase in δ13C. The magnitude of the perturbation is nearly independent of the magnitude of increase in the O2 flux, but highly sensitive to the size of the sedimentary sulfide reservoir being oxidized. In the model, increased delivery of sulfate drives elevated organic carbon burial, as we allow the C:P burial ratio of organic carbon to respond to the O2-to-SO4 ratio. This feedback is based on the notion that in low-O2 / low-SO4 and high-O2 / high-SO4 oceanic states iron oxide precipitation acts as a strong sink for dissolved phosphate, while in the intermediate low-O2 / high-SO4

  15. Effects of a type of quenched randomness on car accidents in a cellular automaton model

    Science.gov (United States)

    Yang, Xian-Qing; Zhang, Wei; Qiu, Kang; Zhao, Yue-Min

    2006-01-01

    In this paper we numerically study the probability Pac of the occurrence of car accidents in the Nagel-Schreckenberg (NS) model with a defect. In the deterministic NS model, numerical results show that there exists a critical value of car density below which no car accident happens. The critical density ρc1 is not related only to the maximum speed of cars, but also to the braking probability at the defect. The braking probability at a defect can enhance, not suppress, the occurrence of car accidents when its value is small. Only the braking probability at the defect is very large, car accidents can be reduced by the bottleneck. In the nondeterministic NS model, the probability Pac exhibits the same behaviors with that in the deterministic model except the case of vmax=1 under which the probability Pac is only reduced by the defect. The defect also induces the inhomogeneous distribution of car accidents over the whole road. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the nondeterministic NS model with vmax=1 in the case of large defect braking probability.

  16. 大型 LNG 储罐泄漏事故后果分析%Consequence Analysis of Leakage Accident of Large LNG Storage Tank

    Institute of Scientific and Technical Information of China (English)

    俞志东; 吴建林

    2016-01-01

    Natural gas is a kind of high quality ,high efficiency ,clean energy ,Which is widely used in various industries .In order to use natural gas Conveniently ,some coastal cities in our country have built many large LNG storage tanks .Liquefied natural gas is the flammable and explosive dangerous goods ,so once a tank leaks ,it may cause very serious consequences .The PHAST software ,once being input the real scene at the time of an accident ,can calculate and analyze the diffusion ,the flash fire ,the fire disaster ,or the explosion immediately , quickly determining the leakage ,diffusion ,combustion and explosion hazard area ,and measuring the personnel death radius ,serious injury radius and minor injury radius caused by the fire thermal radiation and explosion pressure .Analysis of the accident can help receiving sta-tions intuitively understand the degree of danger after the accident so as to take corresponding measures .%天然气是一种优质、高效的清洁能源,广泛地应用于各个行业中。我国部分沿海城市已建造了大型 LNG 接收站,运用PHAST 软件,输入发生事故时的真实场景,可对 LNG 储罐泄漏事故后果进行计算和分析,从而确定泄漏、扩散、燃烧和爆炸等危险区域范围。分析结果能帮助接收站直观了解发生事故后的危险程度,进而能够针对性地采取相应的安全措施。

  17. Evaluation of sanitary consequences of Chernobyl accident in France: epidemiological monitoring device, state of knowledge, evaluation of risks and perspectives; Evaluation des consequences sanitaires de l'accident de Tchernobyl en France: dispositif de surveillance epidemiologique, etat des connaissances, evaluation des risques et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Verger, P.; Champion, D.; Gourmelon, P.; Hubert, Ph.; Joly, J.; Renaud, Ph.; Tirmarche, M.; Vidal, M. [CEA/Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire, IPSN, 92 (France); Cherie-Challine, L.; Boutou, O.; Isnard, H.; Jouan, M.; Pirard, Ph. [Institut National de Veille Sanitaire, 94 - Saint-Maurice (France)

    2000-12-01

    The objectives of this document are firstly, to present the situation of knowledge both on the sanitary consequences of the Chernobyl accident and on the risk factors of thyroid cancers, these ones constituting one of the most principal consequences observed in Belarus, in Ukraine and Russia; secondly, the give the principal system contributing to the epidemiological surveillance of effects coming from a exposure to ionizing radiations, in France and to give the knowledge on incidence and mortality of thyroid cancer in France; thirdly, to discuss the pertinence and the feasibility of epidemiological approaches that could be considered to answer questions that the public and authorities ask relatively to the sanitary consequences of Chernobyl accident in France; fourthly to male a calculation of thyroid cancer risk in relation with Chernobyl fallout in France from works and studies made from 1986 on the consequences of this disaster in terms of radioecology and dosimetry at the national level. Besides, the improvement of thyroid cancer surveillance is also tackled. (N.C.)

  18. Report on the consequences of Chernobylsk accident in France Minister missions from the 25. february to 6. august 2002; Rapport sur les consequences de l'accident de Tchernobyl en France missions ministerielles du 25 fevrier et du 6 aout 2002

    Energy Technology Data Exchange (ETDEWEB)

    Aurengo, A

    2006-04-15

    Actually, we have not any map that gives reliable quantitative data of Chernobylsk accident fallout on soils. The maps proposed for these deposits give order of magnitude; they find east-west gradient conform to the origin of the accident and confirm the importance of the rain. But the quantitative value is only an approximation where the precision is not known (error interval). It does not allow to know the radiation doses to the thyroid because the food contamination does not increase like the soils contamination. It could be possible to improve the models but the scientific council of I.R.S.N. proposes to realize a periodic ground state of soils contamination in cesium. It would be a better step of a more reliable mapping of Chernobylsk accident fallout. (N.C.)

  19. SCIENTIFIC SUPPORT OF THE MEDICAL SECTION OF THE STATE PROGRAM OF THE BELARUS REPUBLIC FOR THE OVERCOMING OF THE CHERNOBYL ACCIDENT CONSEQUENCES

    Directory of Open Access Journals (Sweden)

    A. V. Rozhko

    2012-01-01

    Full Text Available A twenty-five year health follow-up of the affected population has shown that a properly structured State strategy on overcoming the consequences of disaster allow to maintain stable levels of morbidity and mortality. An important achievement in the system of medical help to the affected population is the organization of dynamic follow-up, as well as creating State Register of people exposed to radiation as a result of the Chernobyl accident as a tool for solving scientific and practical problems. The results of scientific researches obtained in the SO “The Republican Research Centre for Radiation Medicine and Human Ecology” were the basis for one of the Council of Ministers Decree and two Decrees of the Ministry of Health. Significant changes have been made in the order of assigning the causation connection of disease (disability and the accident at the Chernobyl nuclear power plant and objective criteria for the formation of high radiation risk groups.In a whole, the rate of oncological morbidity in the affected population remains at the average republican level, but for certain categories of the affected population, referred to groups of enhanced radiation risk, there has been detected the presence of excess morbidity of some forms of malignant neoplasms.

  20. Influence of main variables modifications on accident transient based on AP1000-like MELCOR model

    Science.gov (United States)

    Malicki, M.; Pieńkowski, L.

    2016-09-01

    Analysis of Severe Accidents (SA) is one of the most important parts of nuclear safety researches. MELCOR is a validated system code for severe accident analysis and as such it was used to obtain presented results. Analysed AP1000 model is based on publicly available data only. Sensitivity analysis was done for the main variables of primary reactor coolant system to find their influence on accident transient. This kind of analysis helps to find weak points of reactor design and the model itself. Performed analysis is a base for creation of Small Modular Reactor (SMR) generic model which will be the next step of the investigation aiming to estimate safety level of different reactors. Results clearly help to establish a range of boundary conditions for main the variables in future SMR model.

  1. Object-Oriented Bayesian Networks (OOBN) for Aviation Accident Modeling and Technology Portfolio Impact Assessment

    Science.gov (United States)

    Shih, Ann T.; Ancel, Ersin; Jones, Sharon M.

    2012-01-01

    The concern for reducing aviation safety risk is rising as the National Airspace System in the United States transforms to the Next Generation Air Transportation System (NextGen). The NASA Aviation Safety Program is committed to developing an effective aviation safety technology portfolio to meet the challenges of this transformation and to mitigate relevant safety risks. The paper focuses on the reasoning of selecting Object-Oriented Bayesian Networks (OOBN) as the technique and commercial software for the accident modeling and portfolio assessment. To illustrate the benefits of OOBN in a large and complex aviation accident model, the in-flight Loss-of-Control Accident Framework (LOCAF) constructed as an influence diagram is presented. An OOBN approach not only simplifies construction and maintenance of complex causal networks for the modelers, but also offers a well-organized hierarchical network that is easier for decision makers to exploit the model examining the effectiveness of risk mitigation strategies through technology insertions.

  2. Effects of quenched randomness induced by car accidents on traffic flow in a cellular automata model

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang; Zhao, Yue-Min

    2004-10-01

    In this paper we numerically study the impact of quenched disorder induced by car accidents on traffic flow in the Nagel-Schreckenberg (NS) model. Car accidents occur when the necessary conditions proposed by [Boccara J. Phys. A 30, 3329 (1997)] are satisfied. Two realistic situations of cars involved in car accidents have been considered. Model A is presented to consider that the accident cars become temporarily stuck. Our studies exhibit the “inverse- λ form” or the metastable state for traffic flow in the fundamental diagram and wide-moving waves of jams in the space-time pattern. Model B is proposed to take into account that the “wrecked” cars stay there forever and the cars behind will pass through the sites occupied by the “wrecked” cars with a transmission rate. Four-stage transitions from a maximum flow through a sharp decrease phase and a density-independent phase to a high-density jamming phase for traffic flow have been observed. The density profiles and the effects of transmission rate and probability of the occurrence of car accidents in model B are also discussed.

  3. Development and Validation of Accident Models for FeCrAl Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle Allan Lawrence [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, Jason Dean [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    The purpose of this milestone report is to present the work completed in regards to material model development for FeCrAl cladding and highlight the results of applying these models to Loss of Coolant Accidents (LOCA) and Station Blackouts (SBO). With the limited experimental data available (essentially only the data used to create the models) true validation is not possible. In the absence of another alternative, qualitative comparisons during postulated accident scenarios between FeCrAl and Zircaloy-4 cladded rods have been completed demonstrating the superior performance of FeCrAl.

  4. Final safety analysis report for the Galileo Mission: Volume 2, Book 2: Accident model document: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-15

    This section of the Accident Model Document (AMD) presents the appendices which describe the various analyses that have been conducted for use in the Galileo Final Safety Analysis Report II, Volume II. Included in these appendices are the approaches, techniques, conditions and assumptions used in the development of the analytical models plus the detailed results of the analyses. Also included in these appendices are summaries of the accidents and their associated probabilities and environment models taken from the Shuttle Data Book (NSTS-08116), plus summaries of the several segments of the recent GPHS safety test program. The information presented in these appendices is used in Section 3.0 of the AMD to develop the Failure/Abort Sequence Trees (FASTs) and to determine the fuel releases (source terms) resulting from the potential Space Shuttle/IUS accidents throughout the missions.

  5. Combined Prediction Model of Death Toll for Road Traffic Accidents Based on Independent and Dependent Variables

    Science.gov (United States)

    Zhong-xiang, Feng; Shi-sheng, Lu; Wei-hua, Zhang; Nan-nan, Zhang

    2014-01-01

    In order to build a combined model which can meet the variation rule of death toll data for road traffic accidents and can reflect the influence of multiple factors on traffic accidents and improve prediction accuracy for accidents, the Verhulst model was built based on the number of death tolls for road traffic accidents in China from 2002 to 2011; and car ownership, population, GDP, highway freight volume, highway passenger transportation volume, and highway mileage were chosen as the factors to build the death toll multivariate linear regression model. Then the two models were combined to be a combined prediction model which has weight coefficient. Shapley value method was applied to calculate the weight coefficient by assessing contributions. Finally, the combined model was used to recalculate the number of death tolls from 2002 to 2011, and the combined model was compared with the Verhulst and multivariate linear regression models. The results showed that the new model could not only characterize the death toll data characteristics but also quantify the degree of influence to the death toll by each influencing factor and had high accuracy as well as strong practicability. PMID:25610454

  6. Combined Prediction Model of Death Toll for Road Traffic Accidents Based on Independent and Dependent Variables

    Directory of Open Access Journals (Sweden)

    Feng Zhong-xiang

    2014-01-01

    Full Text Available In order to build a combined model which can meet the variation rule of death toll data for road traffic accidents and can reflect the influence of multiple factors on traffic accidents and improve prediction accuracy for accidents, the Verhulst model was built based on the number of death tolls for road traffic accidents in China from 2002 to 2011; and car ownership, population, GDP, highway freight volume, highway passenger transportation volume, and highway mileage were chosen as the factors to build the death toll multivariate linear regression model. Then the two models were combined to be a combined prediction model which has weight coefficient. Shapley value method was applied to calculate the weight coefficient by assessing contributions. Finally, the combined model was used to recalculate the number of death tolls from 2002 to 2011, and the combined model was compared with the Verhulst and multivariate linear regression models. The results showed that the new model could not only characterize the death toll data characteristics but also quantify the degree of influence to the death toll by each influencing factor and had high accuracy as well as strong practicability.

  7. Ethical Issues Related to the Promotion of a "100 mSv Threshold Assumption" in Japan after the Fukushima Nuclear Accident in 2011: Background and Consequences.

    Science.gov (United States)

    Tsuda, Toshihide; Lindahl, Lena; Tokinobu, Akiko

    2017-06-01

    This article describes the debates in Japan regarding the 100 mSv threshold assumption and ethical issues related to it, and explores the background to distorted risk information and absence of risk communication in Japan. Then we seek proper risk communication based on scientific evidence. On March 11, 2011 an accident occurred at the Fukushima Daiichi Nuclear Power Plant due to the Great East Japan Earthquake. Since then a number of misunderstandings have become common in Japan as a result of public statements by the Japanese and local governments that have no basis in medical science or are contradictory to medical science. Consequently, not only the population of Fukushima Prefecture, but also others, have been subjected to unnecessary exposure to radiation, against the As Low As Reasonably Achievable (ALARA) principle. The number of cases of thyroid cancer has increased by one or two orders of magnitude since the accident in Fukushima. However, the population has hardly been given any correct information from the central and local governments, medical societies, and media. The center of this problem is a statement on radiation-induced cancer (including thyroid cancer) made by the Japanese Government and Japanese medical academic societies indicating that "exposure of less than 100 mSv gives rise to no excess risk of cancer, and even if there is some resulting cancer it will be impossible to detect it" (this will be referred to as "the 100 mSv threshold assumption" from now onward). They have been saying this since April 2011 and have made no effort to correct it. Many Japanese began to notice this but correct information on radiation protection has reached only one part of the population. Risk communication should be based on scientific evidence, and providing it as information for the public is a key element. In Japan, governments and academic societies tried to communicate with the public without doing it. Ethical problems after the accident in Fukushima

  8. Severe accident modeling of a PWR core with different cladding materials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, S. C. [Westinghouse Electric Company LLC, 5801 Bluff Road, Columbia, SC 29209 (United States); Henry, R. E.; Paik, C. Y. [Fauske and Associates, Inc., 16W070 83rd Street, Burr Ridge, IL 60527 (United States)

    2012-07-01

    The MAAP v.4 software has been used to model two severe accident scenarios in nuclear power reactors with three different materials as fuel cladding. The TMI-2 severe accident was modeled with Zircaloy-2 and SiC as clad material and a SBO accident in a Zion-like, 4-loop, Westinghouse PWR was modeled with Zircaloy-2, SiC, and 304 stainless steel as clad material. TMI-2 modeling results indicate that lower peak core temperatures, less H 2 (g) produced, and a smaller mass of molten material would result if SiC was substituted for Zircaloy-2 as cladding. SBO modeling results indicate that the calculated time to RCS rupture would increase by approximately 20 minutes if SiC was substituted for Zircaloy-2. Additionally, when an extended SBO accident (RCS creep rupture failure disabled) was modeled, significantly lower peak core temperatures, less H 2 (g) produced, and a smaller mass of molten material would be generated by substituting SiC for Zircaloy-2 or stainless steel cladding. Because the rate of SiC oxidation reaction with elevated temperature H{sub 2}O (g) was set to 0 for this work, these results should be considered preliminary. However, the benefits of SiC as a more accident tolerant clad material have been shown and additional investigation of SiC as an LWR core material are warranted, specifically investigations of the oxidation kinetics of SiC in H{sub 2}O (g) over the range of temperatures and pressures relevant to severe accidents in LWR 's. (authors)

  9. An Evaluation of the Role that Traffic Culture Plays in Reducing Consequences of Accidents and Promoting Social Security and Order

    Directory of Open Access Journals (Sweden)

    Nasser Pourmoallem

    2013-01-01

    Full Text Available IntroductionAccidents and traffic security have become serious issues in our country, to the extent that most of the people and authorities are severely concerned about them. On the other hand, research shows that human factor has the most important role in the occurrence of accidents. According to the records, only %1 of all accidents in Iran are resulted from "vehicle malfunction" and “immunodeficiency of the roads”; while other events, directly or indirectly, are caused by human wrong operations. Analysis of various factors shows that the human factor is not an element, but is characterized by three axes: (1 drivers and pedestrians, (2 planning and legislation and (3 control factors. In this paper, approaches to develop transportation and traffic security through teaching traffic behaviors to road users are investigated in the framework of three scenarios. Also, the solutions for improving safety, traffic and transportation through culture and education have been investigated. Moreover, the behavior of road users has been studied in the form of these traffic scenarios. Material & MethodsIn scenario No. 1, the importance and the role of traffic culture and behavior in the development of traffic flow is investigated and the process of AHP is used to investigate the decision making processes about the improvement of traffic culture and behavior. In this scenario, the importance of culture together with the role that it plays in improving the safety and facilitative factors of transportation is evaluated. To this end, “improving traffic behavior and culture alongside of the improvement of transport safety and facilitation” is intended to be the assumed target. Therefore, all the factors and parameters effective on the improvement of traffic behavior and culture are the statistical variables in this study:•The training method (culture•The enforcement of traffic laws and regulations variable•The variable of social and psychological

  10. The accident in Fukushima. Preliminary report on the accident progress in the nuclear power plants as a consequence of the earth quake on 11th March 2011; Der Unfall in Fukushima. Zwischenbericht zu den Ablaeufen in den Kernkraftwerken nach dem Erdbeben vom 11. Maerz 2011

    Energy Technology Data Exchange (ETDEWEB)

    Borghoff, Stefan; Brueck, Benjamin; Kilian-Huelsmeyer, Yvonne; Maqua, Michael; Mildenberger, Oliver; Quester, Claudia; Stahl, Thorsten; Thuma, Gernot; Wetzel, Norbert; Wild, Volker

    2011-08-15

    The preliminary report on the accident progress in the nuclear power plants as a consequence of the earth quake on 11th March 2011 describes the chronologic sequence of the accident in the different units of the power plant. The measures for mitigation of the accident impact at the site of Fukushima Daiichi and Fukushima Daini included the efforts to reach and maintain stable plant conditions. The issue radiological situation includes an estimation of the air-borne radionuclide release, the contamination of the environment and the sea water, measures for protection of the public. The lessons learned following the NISA and IAEA fact finding missions and the open questions are summarized.

  11. Usefulness of high resolution coastal models for operational oil spill forecast: the Full City accident

    Science.gov (United States)

    Broström, G.; Carrasco, A.; Hole, L. R.; Dick, S.; Janssen, F.; Mattsson, J.; Berger, S.

    2011-06-01

    Oil spill modeling is considered to be an important decision support system (DeSS) useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas implying that low resolution basin scale ocean models is of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the Full City accident on the Norwegian south coast and compare three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws but including an analysis based on a higher resolution model (1.5 km resolution) for the area the model system show results that compare well with observations. The study also shows that an ensemble using three different models is useful when predicting/analyzing oil spill in coastal areas.

  12. Accident Process and Consequence Research for LOCA Combining with Blackout Accident of Ship Reactor%船用堆破口叠加全船断电事故进程及后果研究

    Institute of Scientific and Technical Information of China (English)

    张帆; 陈航; 张彦招; 晏峰

    2015-01-01

    Using MELCOR code ,the combination of LOCA and blackout accident of ship reactor was modeled and calculated , and the accident process and source term release were researched . The results show that the accident leads to lower head of pressure vessel and bilge creep‐rupture finally without emergency power .The release fraction of inert gases and iodine are above 80% ,the main form of iodine is CsI with great deposit and less airborne fraction .The accident process is decided by the equiva‐lent diameter of break size .The production of H2 is decided by core temperature and water remaining in the core ,but has nothing to do with equivalent diameter of break size .T he probability of H2 detonation is unlikely to occur .T he results can provide tech‐nical support for emergency maintenance and emergency decision‐making .%采用M ELCOR程序,对船用堆破口叠加全船断电事故进行建模计算,并对事故进程和源项释放进行了研究。计算结果表明:若应急电源无法投入,最终将导致压力容器下封头失效和舱底失效;所研究事故的惰性气体、碘释放量均在80%以上,且释放的I主要以CsI形式存在,滞留量大,气载量小。事故进展快慢取决于破口当量尺寸,但氢气的产量与堆芯温度、堆芯残余水量相关,与破口当量尺寸无直接关系,堆舱内发生氢爆可能性不大。本文计算结果可为应急抢修和应急决策提供技术支持。

  13. [Model of Analysis and Prevention of Accidents - MAPA: tool for operational health surveillance].

    Science.gov (United States)

    de Almeida, Ildeberto Muniz; Vilela, Rodolfo Andrade de Gouveia; da Silva, Alessandro José Nunes; Beltran, Sandra Lorena

    2014-12-01

    The analysis of work-related accidents is important for accident surveillance and prevention. Current methods of analysis seek to overcome reductionist views that see these occurrences as simple events explained by operator error. The objective of this paper is to analyze the Model of Analysis and Prevention of Accidents (MAPA) and its use in monitoring interventions, duly highlighting aspects experienced in the use of the tool. The descriptive analytical method was used, introducing the steps of the model. To illustrate contributions and or difficulties, cases where the tool was used in the context of service were selected. MAPA integrates theoretical approaches that have already been tried in studies of accidents by providing useful conceptual support from the data collection stage until conclusion and intervention stages. Besides revealing weaknesses of the traditional approach, it helps identify organizational determinants, such as management failings, system design and safety management involved in the accident. The main challenges lie in the grasp of concepts by users, in exploring organizational aspects upstream in the chain of decisions or at higher levels of the hierarchy, as well as the intervention to change the determinants of these events.

  14. Usefulness of high resolution coastal models for operational oil spill forecast: the "Full City" accident

    Science.gov (United States)

    Broström, G.; Carrasco, A.; Hole, L. R.; Dick, S.; Janssen, F.; Mattsson, J.; Berger, S.

    2011-11-01

    Oil spill modeling is considered to be an important part of a decision support system (DeSS) for oil spill combatment and is useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas, implying that low resolution basin scale ocean models are of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the "Full City" accident on the Norwegian south coast and compare operational simulations from three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws, but by applying ocean forcing data of higher resolution (1.5 km resolution), the model system shows results that compare well with observations. The study also shows that an ensemble of results from the three different models is useful when predicting/analyzing oil spill in coastal areas.

  15. Usefulness of high resolution coastal models for operational oil spill forecast: the "Full City" accident

    Directory of Open Access Journals (Sweden)

    G. Broström

    2011-11-01

    Full Text Available Oil spill modeling is considered to be an important part of a decision support system (DeSS for oil spill combatment and is useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas, implying that low resolution basin scale ocean models are of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the "Full City" accident on the Norwegian south coast and compare operational simulations from three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws, but by applying ocean forcing data of higher resolution (1.5 km resolution, the model system shows results that compare well with observations. The study also shows that an ensemble of results from the three different models is useful when predicting/analyzing oil spill in coastal areas.

  16. Calculation notes that support accident scenario and consequence development for the leak from a railcar/tank trailer at the 204-ar waste unloading facility

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, G.W., Westinghouse Hanford

    1996-09-19

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Leak from Railcar/Tank Trailer. The calculations needed to quantify the risk associated with this accident scenario are included within.

  17. 90Sr and 89Sr in seawater off Japan as a consequence of the Fukushima Dai-ichi nuclear accident

    Directory of Open Access Journals (Sweden)

    K. O. Buesseler

    2013-02-01

    Full Text Available The impact of the earthquake and tsunami in the east coast of Japan in 11 March 2011 caused a loss of power at the Fukushima Dai-ichi Nuclear Power Plant (NPP that resulted in one of the most important releases of artificial radioactivity to the environment. Although several works were devoted to evaluate the atmospheric dispersion of radionuclides, the impact of the discharges to the ocean has been less investigated. Here we evaluate the distribution of Fukushima-derived 90Sr and 89Sr throughout waters 30–600 km offshore in June 2011. Concentrations of 90Sr and 89Sr in both surface waters and shallow profiles ranged from 0.8 ± 0.2 to 85 ± 3 Bq m−3 and from 19 ± 6 to 265 ± 74 Bq m−3, respectively. Because of its short half-life, all measured 89Sr was due to the accident, while the 90Sr concentrations can be compared to the background levels in the Pacific Ocean of about 1.2 Bq m−3. Fukushima-derived radiostrontium was mainly detected north of Kuroshio Current, as this was acting as a southern boundary for transport. The highest activities were associated with near-shore eddies, and larger inventories were found in the closest stations to Fukushima NPP. The data evidences a major influence of direct liquid discharges of radiostrontium compared to the atmospheric deposition. Existing 137Cs data reported from the same samples allowed us establishing a 90Sr/137Cs ratio of 0.0256 ± 0.0006 in seawater off Fukushima, being significantly different than that of the global atmospheric fallout (i.e. 0.63 and may be used in future studies to track waters coming from the east coast of Japan. Liquid discharges of 90Sr to the ocean were estimated, resulting in an inventory of 53 ± 1 TBq of 90Sr in the inshore study area in June 2011 and total releases of 90Sr ranging from 90 to 900 TBq, depending upon the reported estimates of 137Cs releases that are considered.

  18. 90Sr and 89Sr in seawater off Japan as a consequence of the Fukushima Dai-ichi nuclear accident

    Directory of Open Access Journals (Sweden)

    N. Casacuberta

    2013-06-01

    Full Text Available The impact of the earthquake and tsunami on the east coast of Japan on 11 March 2011 caused a loss of power at the Fukushima Dai-ichi nuclear power plant (NPP that resulted in one of the most important releases of artificial radioactivity into the environment. Although several works were devoted to evaluating the atmospheric dispersion of radionuclides, the impact of the discharges to the ocean has been less investigated. Here we evaluate the distribution of Fukushima-derived 90Sr (n = 57 and 89Sr (n = 19 throughout waters 30–600 km offshore in June 2011. Concentrations of 90Sr and 89Sr in both surface waters and shallow profiles ranged from 0.8 ± 0.2 to 85 ± 3 Bq m−3 and from 19 ± 6 to 265 ± 74 Bq m−3, respectively. Because of its short half-life, all measured 89Sr was due to the accident, while the 90Sr concentrations can be compared to the background levels in the Pacific Ocean of about 1.2 Bq m−3. Fukushima-derived radiostrontium was mainly detected north of Kuroshio Current, as this was acting as a southern boundary for transport. The highest activities were associated with near-shore eddies, and larger inventories were found in the closest stations to Fukushima NPP. The data evidence a major influence of direct liquid discharges of radiostrontium compared to the atmospheric deposition. Existing 137Cs data reported from the same samples allowed us to establish a 90Sr / 137Cs ratio of 0.0256 ± 0.0006 in seawater off Fukushima, being significantly different than that of the global atmospheric fallout (i.e., 0.63 and may be used in future studies to track waters coming from the east coast of Japan. Liquid discharges of 90Sr to the ocean were estimated, resulting in an inventory of 53 ± 1 TBq of 90Sr in the inshore study area in June 2011 and total releases of 90Sr ranging from 90 to 900 TBq, depending upon the reported estimates of 137Cs releases that are considered.

  19. 90Sr and 89Sr in seawater off Japan as a consequence of the Fukushima Dai-ichi nuclear accident

    Science.gov (United States)

    Casacuberta, N.; Masqué, P.; Garcia-Orellana, J.; Garcia-Tenorio, R.; Buesseler, K. O.

    2013-06-01

    The impact of the earthquake and tsunami on the east coast of Japan on 11 March 2011 caused a loss of power at the Fukushima Dai-ichi nuclear power plant (NPP) that resulted in one of the most important releases of artificial radioactivity into the environment. Although several works were devoted to evaluating the atmospheric dispersion of radionuclides, the impact of the discharges to the ocean has been less investigated. Here we evaluate the distribution of Fukushima-derived 90Sr (n = 57) and 89Sr (n = 19) throughout waters 30-600 km offshore in June 2011. Concentrations of 90Sr and 89Sr in both surface waters and shallow profiles ranged from 0.8 ± 0.2 to 85 ± 3 Bq m-3 and from 19 ± 6 to 265 ± 74 Bq m-3, respectively. Because of its short half-life, all measured 89Sr was due to the accident, while the 90Sr concentrations can be compared to the background levels in the Pacific Ocean of about 1.2 Bq m-3. Fukushima-derived radiostrontium was mainly detected north of Kuroshio Current, as this was acting as a southern boundary for transport. The highest activities were associated with near-shore eddies, and larger inventories were found in the closest stations to Fukushima NPP. The data evidence a major influence of direct liquid discharges of radiostrontium compared to the atmospheric deposition. Existing 137Cs data reported from the same samples allowed us to establish a 90Sr / 137Cs ratio of 0.0256 ± 0.0006 in seawater off Fukushima, being significantly different than that of the global atmospheric fallout (i.e., 0.63) and may be used in future studies to track waters coming from the east coast of Japan. Liquid discharges of 90Sr to the ocean were estimated, resulting in an inventory of 53 ± 1 TBq of 90Sr in the inshore study area in June 2011 and total releases of 90Sr ranging from 90 to 900 TBq, depending upon the reported estimates of 137Cs releases that are considered.

  20. Sodium fast reactor gaps analysis of computer codes and models for accident analysis and reactor safety.

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, Juan (Oak Ridge National Laboratory, Oak Ridge, TN); Jeong, Hae-Yong (Korea Atomic Energy Research Institute, Daejeon, Korea); Wigeland, Roald (Idaho National Laboratory, Idaho Falls, ID); Corradini, Michael (University of Wisconsin, Madison, WI); Schmidt, Rodney Cannon; Thomas, Justin (Argonne National Laboratory, Argonne, IL); Wei, Tom (Argonne National Laboratory, Argonne, IL); Sofu, Tanju (Argonne National Laboratory, Argonne, IL); Ludewig, Hans (Brookhaven National Laboratory, Upton, NY); Tobita, Yoshiharu (Japan Atomic Energy Agency, Ibaraki-ken, Japan); Ohshima, Hiroyuki (Japan Atomic Energy Agency, Ibaraki-ken, Japan); Serre, Frederic (Centre d' %C3%94etudes nucl%C3%94eaires de Cadarache %3CU%2B2013%3E CEA, France)

    2011-06-01

    This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and identify important gaps. During the review, panel members identified over 60 computer codes that are currently available in the international community to perform different aspects of SFR safety analysis for various event scenarios and accident categories. A brief description of each of these codes together with references (when available) is provided. An adaptation of the Predictive Capability Maturity Model (PCMM) for computational modeling and simulation is described for use in this work. The panel's assessment of the available US codes is presented in the form of nine tables, organized into groups of three for each of three risk categories considered: anticipated operational occurrences (AOOs), design basis accidents (DBA), and beyond design basis accidents (BDBA). A set of summary conclusions are drawn from the results obtained. At the highest level, the panel judged that current US code capabilities are adequate for licensing given reasonable margins, but expressed concern that US code development activities had stagnated and that the

  1. Radiation risk models for all solid cancers other than those types of cancer requiring individual assessments after a nuclear accident.

    Science.gov (United States)

    Walsh, Linda; Zhang, Wei

    2016-03-01

    In the assessment of health risks after nuclear accidents, some health consequences require special attention. For example, in their 2013 report on health risk assessment after the Fukushima nuclear accident, the World Health Organisation (WHO) panel of experts considered risks of breast cancer, thyroid cancer and leukaemia. For these specific cancer types, use was made of already published excess relative risk (ERR) and excess absolute risk (EAR) models for radiation-related cancer incidence fitted to the epidemiological data from the Japanese A-bomb Life Span Study (LSS). However, it was also considered important to assess all other types of solid cancer together and the WHO, in their above-mentioned report, stated "No model to calculate the risk for all other solid cancer excluding breast and thyroid cancer risks is available from the LSS data". Applying the LSS models for all solid cancers along with the models for the specific sites means that some cancers have an overlap in the risk evaluations. Thus, calculating the total solid cancer risk plus the breast cancer risk plus the thyroid cancer risk can overestimate the total risk by several per cent. Therefore, the purpose of this paper was to publish the required models for all other solid cancers, i.e. all solid cancers other than those types of cancer requiring special attention after a nuclear accident. The new models presented here have been fitted to the same LSS data set from which the risks provided by the WHO were derived. Although it is known already that the EAR and ERR effect modifications by sex are statistically significant for the outcome "all solid cancer", it is shown here that sex modification is not statistically significant for the outcome "all solid cancer other than thyroid and breast cancer". It is also shown here that the sex-averaged solid cancer risks with and without the sex modification are very similar once breast and thyroid cancers are factored out. Some other notable model

  2. Learning lessons from Natech accidents - the eNATECH accident database

    Science.gov (United States)

    Krausmann, Elisabeth; Girgin, Serkan

    2016-04-01

    equipment vulnerability models linking the natural-hazard severity to the observed damage almost impossible. As a consequence, the European Commission has set up the eNATECH database for the systematic collection of Natech accident data and near misses. The database exhibits the more sophisticated accident representation required to capture the characteristics of Natech events and is publicly accessible at http://enatech.jrc.ec.europa.eu. This presentation outlines the general lessons-learning process, introduces the eNATECH database and its specific structure, and discusses natural-hazard specific lessons learned and features common to Natech accidents triggered by different natural hazards.

  3. Modelling transport and deposition of caesium and iodine from the Chernobyl accident using the DREAM model

    Directory of Open Access Journals (Sweden)

    J. Brandt

    2002-01-01

    Full Text Available A tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model, has been developed for modelling transport, dispersion and deposition (wet and dry of radioactive material from accidental releases, as the Chernobyl accident. The model is a combination of a Lagrangian model, that includes the near source dispersion, and an Eulerian model describing the long-range transport. The performance of the transport model has previously been tested within the European Tracer Experiment, ETEX, which included transport and dispersion of an inert, non-depositing tracer from a controlled release. The focus of this paper is the model performance with respect to the total deposition of  137Cs, 134Cs and 131I from the Chernobyl accident, using different relatively simple and comprehensive parameterizations for dry- and wet deposition. The performance, compared to measurements, of using different combinations of two different wet deposition parameterizations and three different parameterizations of dry deposition has been evaluated, using different statistical tests. The best model performance, compared to measurements, is obtained when parameterizing the total deposition combined of a simple method for dry deposition and a subgrid-scale averaging scheme for wet deposition based on relative humidities. The same major conclusion is obtained for all the three different radioactive isotopes and using two different deposition measurement databases. Large differences are seen in the results obtained by using the two different parameterizations of wet deposition based on precipitation rates and relative humidities, respectively. The parameterization based on subgrid-scale averaging is, in all cases, performing better than the parameterization based on precipitation rates. This indicates that the in-cloud scavenging process is more important than the below cloud scavenging process for the submicron particles and that the precipitation rates are

  4. [Guilty victims: a model to perpetuate impunity for work-related accidents].

    Science.gov (United States)

    Vilela, Rodolfo Andrade Gouveia; Iguti, Aparecida Mari; Almeida, Ildeberto Muniz

    2004-01-01

    This article analyzes reports and data from the investigation of severe and fatal work-related accidents by the Regional Institute of Criminology in Piracicaba, São Paulo State, Brazil. Some 71 accident investigation reports were analyzed from 1998, 1999, and 2000. Accidents involving machinery represented 38.0% of the total, followed by high falls (15.5%), and electric shocks (11.3%). The reports conclude that 80.0% of the accidents are caused by "unsafe acts" committed by workers themselves, while the lack of safety or "unsafe conditions" account for only 15.5% of cases. Victims are blamed even in situations involving high risk in which not even minimum safety conditions are adopted, thus favoring employers' interests. Such conclusions reflect traditional reductionist explanatory models, in which accidents are viewed as simple, unicausal phenomena, generally focused on slipups and errors by the workers themselves. Despite criticism in recent decades from the technical and academic community, this concept is still hegemonic, thus jeopardizing the development of preventive policies and the improvement of work conditions.

  5. A graph model for preventing railway accidents based on the maximal information coefficient

    Science.gov (United States)

    Shao, Fubo; Li, Keping

    2017-01-01

    A number of factors influences railway safety. It is an important work to identify important influencing factors and to build the relationship between railway accident and its influencing factors. The maximal information coefficient (MIC) is a good measure of dependence for two-variable relationships which can capture a wide range of associations. Employing MIC, a graph model is proposed for preventing railway accidents which avoids complex mathematical computation. In the graph, nodes denote influencing factors of railway accidents and edges represent dependence of the two linked factors. With the increasing of dependence level, the graph changes from a globally coupled graph to isolated points. Moreover, the important influencing factors are identified from many factors which are the monitor key. Then the relationship between railway accident and important influencing factors is obtained by employing the artificial neural networks. With the relationship, a warning mechanism is built by giving the dangerous zone. If the related factors fall into the dangerous zone in railway operations, the warning level should be raised. The built warning mechanism can prevent railway accidents and can promote railway safety.

  6. Instrument Fault Detection Sensitivity of an Empirical Model under Accident Condition in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hwan; Hur, Seop; Cheon, Se Woo; Kim, Jung Taek [KAERI, Daejeon (Korea, Republic of)

    2014-08-15

    After the recent accident in Fukushima, Japan, it has been proven that we cannot obtain fully reliable information from instruments during severe accident conditions. Although the reactor core really melted down, the RV water level indicator showed a more optimistic value than the actual conditions. Accordingly, plant operators were under the misunderstanding that the core was not exposed. This caused confusion for the incident response. Therefore, it is necessary to be equipped with a function that informs operators of the status of the instrument integrity in real time. If plant operators verify that the instruments are working properly during accident conditions, they able to make safer decisions. In an effort to solve this problem, we considered an empirical model using a Process Equipment Monitoring (PEM) tool as a method of instrument diagnosis in a nuclear power plant.

  7. Multilevel modelling for the regional effect of enforcement on road accidents.

    Science.gov (United States)

    Yannis, George; Papadimitriou, Eleonora; Antoniou, Constantinos

    2007-07-01

    This paper investigates the effect of the intensification of Police enforcement on the number of road accidents at national and regional level in Greece, focusing on one of the most important road safety violations: drinking-and-driving. Multilevel negative binomial models are developed to describe the effect of the intensification of alcohol enforcement on the reduction of road accidents in different regions of Greece. Moreover, two approaches are explored as far as regional clustering is concerned: the first one concerns an ad hoc geographical clustering and the second one is based on the results of mathematical cluster analysis through demographic, transport and road safety characteristics. Results indicate that there are significant spatial dependences among road accidents and enforcement. Additionally, it is shown that these dependences are more efficiently interpreted when regions are determined on the basis of qualitative similarities than on the basis of geographical adjacency.

  8. Improvement of radiological consequence estimation methodologies for NPP accidents in the ARGOS and RODOS decision support systems through consideration of contaminant physico-chemical forms

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, K.G.; Roos, P. [Technical University of Denmark - DTU (Denmark); Lind, O.C.; Salbu, B. [Norwegian University of Life Sciences/CERAD - NMBU (Norway); Bujan, A.; Duranova, T. [VUJE, Inc. (Slovakia); Ikonomopoulos, A.; Andronopoulos, S. [National Centre for Scientific Research ' Demokritos' (Greece)

    2014-07-01

    The European standard computerized decision support systems RODOS and ARGOS, which are integrated in the operational nuclear emergency preparedness in practically all European countries, as well as in a range of non-European countries, are highly valuable tools for radiological consequence estimation, e.g., in connection with planning and exercising as well as in justification and optimization of intervention strategies. Differences between the Chernobyl and Fukushima accident atmospheric release source terms have demonstrated that differences in release conditions and processes may lead to very different degrees of volatilization of some radionuclides. Also the physico-chemical properties of radionuclides released can depend strongly on the release process. An example from the Chernobyl accident of the significance of this is that strontium particles released in the fire were oxidized and thus generally physico-chemically different from those released during the preceding explosion. This is reflected in the very different environmental mobility of the two groups of particles. The initial elemental matrix characteristics of the contaminants, as well as environmental parameters like pH, determine for instance the particle dissolution time functions, and thus the environmental mobility and potential for uptake in living organisms. As ICRP recommends optimization of intervention according to residual dose, it is crucial to estimate long term dose contributions adequately. In the EURATOM FP7 project PREPARE, an effort is made to integrate physico-chemical forms of contaminants in scenario-specific source term determination, thereby enabling consideration of influences on atmospheric dispersion/deposition, post-deposition migration, and effectiveness of countermeasure implementation. The first step in this context was to investigate, based on available experience, the important physico-chemical properties of radio-contaminants that might potentially be released to the

  9. Biomechanical models to simulate consequences of maxillofacial surgery

    CERN Document Server

    Payan, Y; Pelorson, X; Vilain, C; Levy, P; Luboz, V; Perrier, P; Payan, Yohan; Chabanas, Matthieu; Pelorson, Xavier; Vilain, Coriandre; Levy, Patrick; Luboz, Vincent; Perrier, Pascal

    2002-01-01

    This paper presents the biomechanical finite element models that have been developed in the framework of the computer-assisted maxillofacial surgery. After a brief overview of the continuous elastic modelling method, two models are introduced and their use for computer-assisted applications discussed. The first model deals with orthognathic surgery and aims at predicting the facial consequences of maxillary and mandibular osteotomies. For this, a generic three-dimensional model of the face is automatically adapted to the morphology of the patient by the mean of elastic registration. Qualitative simulations of the consequences of an osteotomy of the mandible can thus be provided. The second model addresses the Sleep Apnoea Syndrome. Its aim is to develop a complete modelling of the interaction between airflow and upper airways walls during respiration. Dynamical simulations of the interaction during a respiratory cycle are computed and compared with observed phenomena.

  10. Development of a parametric containment event tree model of a severe PWR accident

    Energy Technology Data Exchange (ETDEWEB)

    Okkonen, T. [OTO-Consulting Ay, Helsinki (Finland)

    1996-06-01

    The study supports the development project of STUK on `Living` PSA Level 2. The main work objective is to develop review tools for the Level 2 PSA studies underway at the utilities. The SPSA (STUK PSA) code is specifically designed for the purpose. In this work, SPSA is utilized as the Level 2 programming and calculation tool. A containment event tree (CET) model is built for analysis of severe accidents at the Loviisa pressurized water reactor (PWR) units. Parametric models of severe accident progression and fission product behaviour are developed and integrated in order to construct a compact and self-contained Level 2 PSA model. The model can be easily updated to include new research results, and so it facilitates the Living PSA concept on Level 2 as well. The analyses of the study are limited to severe accidents starting from full-power operation and leading to core melting at a low primary system pressure. Severe accident progression from five plant damage states (PDSs) is examined, however the integration with Level 1 is deferred to more definitive, integrated, safety assessments. (34 refs., 5 figs., 9 tabs.).

  11. Input-output model for MACCS nuclear accident impacts estimation¹

    Energy Technology Data Exchange (ETDEWEB)

    Outkin, Alexander V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bixler, Nathan E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vargas, Vanessa N [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-27

    Since the original economic model for MACCS was developed, better quality economic data (as well as the tools to gather and process it) and better computational capabilities have become available. The update of the economic impacts component of the MACCS legacy model will provide improved estimates of business disruptions through the use of Input-Output based economic impact estimation. This paper presents an updated MACCS model, bases on Input-Output methodology, in which economic impacts are calculated using the Regional Economic Accounting analysis tool (REAcct) created at Sandia National Laboratories. This new GDP-based model allows quick and consistent estimation of gross domestic product (GDP) losses due to nuclear power plant accidents. This paper outlines the steps taken to combine the REAcct Input-Output-based model with the MACCS code, describes the GDP loss calculation, and discusses the parameters and modeling assumptions necessary for the estimation of long-term effects of nuclear power plant accidents.

  12. 汽油储罐化学爆炸事故后果模拟分析%Simulation Analysis of the Consequence of Chemical Gasoline Tank Explosion Accident

    Institute of Scientific and Technical Information of China (English)

    张啸

    2014-01-01

    一直以来,汽油储罐化学爆炸事故模型被用来评审加油站的安全评价报告,所以本文通过实际模拟计算来分析汽油储罐化学爆炸事故模型,以方便加油站进行安全管理。%Chemical gasoline tank explosion accident model has been used to review the safety assessment report of the gas station for a long time. So this article analyzes the chemical gasoline tank explosion model through the actual simulation to facilitate the gas station for safety management.

  13. Modeling Zero – Inflated Regression of Road Accidents at Johor Federal Road F001

    Directory of Open Access Journals (Sweden)

    Prasetijo Joewono

    2016-01-01

    Full Text Available This study focused on the Poisson regression with excess zero outcomes on the response variable. A generalized linear modelling technique such as Poisson regression model and Negative Binomial model was found to be insignificant in explaining and handle over dispersion which due to high amount of zeros thus Zero Inflated model was introduced to overcome the problem. The application work on the number of road accidents on F001 Jalan Jb – Air Hitam. Data on road accident were collected for five-year period from 2010 through 2014. The result from analysis show that ZINB model performed best, in terms of the comparative criteria based on the P value less than 0.05.

  14. System analysis with improved thermo-mechanical fuel rod models for modeling current and advanced LWR materials in accident scenarios

    Science.gov (United States)

    Porter, Ian Edward

    A nuclear reactor systems code has the ability to model the system response in an accident scenario based on known initial conditions at the onset of the transient. However, there has been a tendency for these codes to lack the detailed thermo-mechanical fuel rod response models needed for accurate prediction of fuel rod failure. This proposed work will couple today's most widely used steady-state (FRAPCON) and transient (FRAPTRAN) fuel rod models with a systems code TRACE for best-estimate modeling of system response in accident scenarios such as a loss of coolant accident (LOCA). In doing so, code modifications will be made to model gamma heating in LWRs during steady-state and accident conditions and to improve fuel rod thermal/mechanical analysis by allowing axial nodalization of burnup-dependent phenomena such as swelling, cladding creep and oxidation. With the ability to model both burnup-dependent parameters and transient fuel rod response, a fuel dispersal study will be conducted using a hypothetical accident scenario under both PWR and BWR conditions to determine the amount of fuel dispersed under varying conditions. Due to the fuel fragmentation size and internal rod pressure both being dependent on burnup, this analysis will be conducted at beginning, middle and end of cycle to examine the effects that cycle time can play on fuel rod failure and dispersal. Current fuel rod and system codes used by the Nuclear Regulatory Commission (NRC) are compilations of legacy codes with only commonly used light water reactor materials, Uranium Dioxide (UO2), Mixed Oxide (U/PuO 2) and zirconium alloys. However, the events at Fukushima Daiichi and Three Mile Island accident have shown the need for exploration into advanced materials possessing improved accident tolerance. This work looks to further modify the NRC codes to include silicon carbide (SiC), an advanced cladding material proposed by current DOE funded research on accident tolerant fuels (ATF). Several

  15. Prevaba: a Bayesian Model to Predict the Existence of Victims in car accidents

    Directory of Open Access Journals (Sweden)

    TELLES, M.J.

    2015-12-01

    Full Text Available Road safety is an area which is concerned with both the reduction of accidents as with the care provided to the victims. Several initiatives are proposed to assist with reducing the number of accidents, such as surveillance, awareness campaigns and support equipment to drivers. Other initiatives for prevention and protection are proposed by vehicle manufacturers in terms of requirements of governament entities. As a final resort, that is, in the event of the accident and the victim needs medical attention, this should be done as quickly as possible. To assist in identifying the existence of the victim and the need for medical care, we propose a Bayesian model, called Prevaba, which uses Bayesian Networks (BN, which aims to predict the existence of victims in traffic accidents. In order to validate the model, we developed a prototype that performed the actual data classification in Porto Alegre - RS for the year 2013. The prototype made the classification based on the previous year's data (2012, showing an index above 90% accuracy, taking into account the incorrect classications are only classified as victimless, but actually was has a victim.

  16. BRAIN INJURY BIOMECHANICS IN REAL WORLD VEHICLE ACCIDENT USING MATHEMATICAL MODELS

    Institute of Scientific and Technical Information of China (English)

    YANG Jikuang; XU Wei; OTTE Dietmar

    2008-01-01

    This paper aims at investigating brain injury mechanisms and predicting head injuries in real world accidents. For this purpose, a 3D human head finite element model (HBM-head) was developed based on head-brain anatomy. The HBM head model was validated with two experimental tests. Then the head finite element(FE) model and a multi-body system (MBS) model were used to carry out reconstructions of real world vehicle-pedestrian accidents and brain injuries. The MBS models were used for calculating the head impact conditions in vehicle impacts. The HBM-head model was used for calculating the injury related physical parameters, such as intracranial pressure, stress, and strain. The calculated intracranial pressure and strain distribution were correlated with the injury outcomes observed from accidents. It is shown that this model can predict the intracranial biomechanical response and calculate the injury related physical parameters. The head FE model has good biofidelity and will be a valuable tool for the study of injury mechanisms and the tolerance level of the brain.

  17. Dynamic modelling of radionuclide uptake by marine biota: application to the Fukushima nuclear power plant accident.

    Science.gov (United States)

    Vives i Batlle, Jordi

    2016-01-01

    The dynamic model D-DAT was developed to study the dynamics of radionuclide uptake and turnover in biota and sediments in the immediate aftermath of the Fukushima accident. This dynamics is determined by the interplay between the residence time of radionuclides in seawater/sediments and the biological half-lives of elimination by the biota. The model calculates time-variable activity concentration of (131)I, (134)Cs, (137)Cs and (90)Sr in seabed sediment, fish, crustaceans, molluscs and macroalgae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of the model is the inclusion of dynamic transfer of radionuclides to/from sediments by factorising the depletion of radionuclides adsorbed onto suspended particulates, molecular diffusion, pore water mixing and bioturbation, represented by a simple set of differential equations coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment more realistically. The model was used to assess the radiological impact of the Fukushima accident on marine biota in the acute phase of the accident. Sediment and biota activity concentrations are within the wide range of actual monitoring data. Activity concentrations in marine biota are thus shown to be better calculated by a dynamic model than with the simpler equilibrium approach based on concentration factors, which tends to overestimate for the acute accident period. Modelled dose rates from external exposure from sediment are also significantly below equilibrium predictions. The model calculations confirm previous studies showing that radioactivity levels in marine biota have been generally below the levels necessary to cause a measurable effect on populations. The model was used in mass-balance mode to calculate total integrated releases of 103, 30 and 3 PBq for (131)I, (137)Cs and (90)Sr, reasonably in line with previous

  18. Consequence modeling for nuclear weapons probabilistic cost/benefit analyses of safety retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, T.F.; Peters, L.; Serduke, F.J.D.; Hall, C.; Stephens, D.R.

    1998-01-01

    The consequence models used in former studies of costs and benefits of enhanced safety retrofits are considered for (1) fuel fires; (2) non-nuclear detonations; and, (3) unintended nuclear detonations. Estimates of consequences were made using a representative accident location, i.e., an assumed mixed suburban-rural site. We have explicitly quantified land- use impacts and human-health effects (e.g. , prompt fatalities, prompt injuries, latent cancer fatalities, low- levels of radiation exposure, and clean-up areas). Uncertainty in the wind direction is quantified and used in a Monte Carlo calculation to estimate a range of results for a fuel fire with uncertain respirable amounts of released Pu. We define a nuclear source term and discuss damage levels of concern. Ranges of damages are estimated by quantifying health impacts and property damages. We discuss our dispersal and prompt effects models in some detail. The models used to loft the Pu and fission products and their particle sizes are emphasized.

  19. Consequences analysis of accidents in an air-propane plant; Analise de consequencias de acidentes numa planta de ar propanado

    Energy Technology Data Exchange (ETDEWEB)

    Lucena, Sergio; Lima Flho, Nelson M. de; Martins, Andrea do N. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Campos, Michel F. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Zimmerle, Sergio Ricardo T.S. [Companhia Pernambucana de Gas (COPERGAS), Recife, PE (Brazil); Alencar, Joao Rui B. de [LAFEPE - Laboratorio Farmaceutico do Estado de Pernambuco S/A, Recife, PE (Brazil); Martins, Andrea do N. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2004-07-01

    The Universidade Federal do Rio Grande do Norte has been developing prototype ovens, which work with natural gas. All the project of the prototypes, which will be applied to ceramic, bread bake industry and incineration of the hospital garbage, needs to be studied, developed and tested carefully until its conclusion. Then VRML language (Virtual Reality Modelling Language) is used as a tool in the study of the engineering projects and simulation of some tests. The main benefits of the use of this tool are: finding and solving problems in the project of the prototypes faster; optimization in the project since the three-dimensional visualization facilitates the study ; and simulation of aspects of functioning of the ovens before its construction. (author)

  20. Consequences analysis of accidents in an air-propane plant; Analise de consequencias de acidentes numa planta de ar propanado

    Energy Technology Data Exchange (ETDEWEB)

    Lucena, Sergio; Lima Flho, Nelson M. de; Martins, Andrea do N. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Campos, Michel F. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Zimmerle, Sergio Ricardo T.S. [Companhia Pernambucana de Gas (COPERGAS), Recife, PE (Brazil); Alencar, Joao Rui B. de [LAFEPE - Laboratorio Farmaceutico do Estado de Pernambuco S/A, Recife, PE (Brazil); Martins, Andrea do N. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2004-07-01

    The Universidade Federal do Rio Grande do Norte has been developing prototype ovens, which work with natural gas. All the project of the prototypes, which will be applied to ceramic, bread bake industry and incineration of the hospital garbage, needs to be studied, developed and tested carefully until its conclusion. Then VRML language (Virtual Reality Modelling Language) is used as a tool in the study of the engineering projects and simulation of some tests. The main benefits of the use of this tool are: finding and solving problems in the project of the prototypes faster; optimization in the project since the three-dimensional visualization facilitates the study ; and simulation of aspects of functioning of the ovens before its construction. (author)

  1. Probabilistic consequence model of accidenal or intentional chemical releases.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.-S.; Samsa, M. E.; Folga, S. M.; Hartmann, H. M.

    2008-06-02

    In this work, general methodologies for evaluating the impacts of large-scale toxic chemical releases are proposed. The potential numbers of injuries and fatalities, the numbers of hospital beds, and the geographical areas rendered unusable during and some time after the occurrence and passage of a toxic plume are estimated on a probabilistic basis. To arrive at these estimates, historical accidental release data, maximum stored volumes, and meteorological data were used as inputs into the SLAB accidental chemical release model. Toxic gas footprints from the model were overlaid onto detailed population and hospital distribution data for a given region to estimate potential impacts. Output results are in the form of a generic statistical distribution of injuries and fatalities associated with specific toxic chemicals and regions of the United States. In addition, indoor hazards were estimated, so the model can provide contingency plans for either shelter-in-place or evacuation when an accident occurs. The stochastic distributions of injuries and fatalities are being used in a U.S. Department of Homeland Security-sponsored decision support system as source terms for a Monte Carlo simulation that evaluates potential measures for mitigating terrorist threats. This information can also be used to support the formulation of evacuation plans and to estimate damage and cleanup costs.

  2. Accident tolerant clad material modeling by MELCOR: Benchmark for SURRY Short Term Station Black Out

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: jwang564@wisc.edu [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Mccabe, Mckinleigh [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Wu, Lei [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Dong, Xiaomeng [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Wang, Xianmao [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Haskin, Troy Christopher [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Corradini, Michael L., E-mail: corradini@engr.wisc.edu [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States)

    2017-03-15

    Highlights: • Thermo-physical and oxidation kinetics properties calculation and analysis of FeCrAl. • Properties modelling of FeCrAl in MELCOR. • Benchmark calculation of Surry nuclear power plant. - Abstract: Accident tolerant fuel and cladding materials are being investigated to provide a greater resistance to fuel degradation, oxidation and melting if long-term cooling is lost in a Light Water Reactor (LWR) following an accident such as a Station Blackout (SBO) or Loss of Coolant Accident (LOCA). Researchers at UW-Madison are analyzing an SBO sequence and examining the effect of a loss of auxiliary feedwater (AFW) with the MELCOR systems code. Our research work considers accident tolerant cladding materials (e.g., FeCrAl alloy) and their effect on the accident behavior. We first gathered the physical properties of this alternative cladding material via literature review and compared it to the usual zirconium alloys used in LWRs. We then developed a model for the Surry reactor for a Short-term SBO sequence and examined the effect of replacing FeCrAl for Zircaloy cladding. The analysis uses MELCOR, Version 1.8.6 YR, which is developed by Idaho National Laboratory in collaboration with MELCOR developers at Sandia National Laboratories. This version allows the user to alter the cladding material considered, and our study examines the behavior of the FeCrAl alloy as a substitute for Zircaloy. Our benchmark comparisons with the Sandia National Laboratory’s analysis of Surry using MELCOR 1.8.6 and the more recent MELCOR 2.1 indicate good overall agreement through the early phases of the accident progression. When FeCrAl is substituted for Zircaloy to examine its performance, we confirmed that FeCrAl slows the accident progression and reduce the amount of hydrogen generated. Our analyses also show that this special version of MELCOR can be used to evaluate other potential ATF cladding materials, e.g., SiC as well as innovative coatings on zirconium cladding

  3. Development of an Ontology to Assist the Modeling of Accident Scenarii "Application on Railroad Transport "

    CERN Document Server

    Maalel, Ahmed; Mejri, Lassad; Ghezela, Henda Hajjami Ben

    2012-01-01

    In a world where communication and information sharing are at the heart of our business, the terminology needs are most pressing. It has become imperative to identify the terms used and defined in a consensual and coherent way while preserving linguistic diversity. To streamline and strengthen the process of acquisition, representation and exploitation of scenarii of train accidents, it is necessary to harmonize and standardize the terminology used by players in the security field. The research aims to significantly improve analytical activities and operations of the various safety studies, by tracking the error in system, hardware, software and human. This paper presents the contribution of ontology to modeling scenarii for rail accidents through a knowledge model based on a generic ontology and domain ontology. After a detailed presentation of the state of the art material, this article presents the first results of the developed model.

  4. Preliminary modeling of the TMI-2 accident with MELPROG-TRAC

    Energy Technology Data Exchange (ETDEWEB)

    Jenks, R.P.

    1988-01-01

    In support of Nuclear Regulatory Commission and Organization for Economic Cooperation and Development (OECD)-sponsored Three Mile Island-Unit 2 (TMI-2) Analysis Exercise studies, work has been performed to develop a simulation model of the TMI-2 plant for use with the integrated MELPROG-TRAC computer code. Numerous nuclear power plant simulation studies have been performed with the TRAC computer code in the past. Some of these addressed the TMI-2 accident or other hypothetical events at the TMI plant. In addition, studies have been previously performed with the MELPROG-TRAC code using Oconee-1 and Surry plant models. This paper describes the preliminary MELPROG-TRAC input model for severe accident analysis.

  5. Generation IV benchmarking of TRISO fuel performance models under accident conditions: Modeling input data

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison

  6. Generation IV benchmarking of TRISO fuel performance models under accident conditions: Modeling input data

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison

  7. Time series count data models: an empirical application to traffic accidents.

    Science.gov (United States)

    Quddus, Mohammed A

    2008-09-01

    Count data are primarily categorised as cross-sectional, time series, and panel. Over the past decade, Poisson and Negative Binomial (NB) models have been used widely to analyse cross-sectional and time series count data, and random effect and fixed effect Poisson and NB models have been used to analyse panel count data. However, recent literature suggests that although the underlying distributional assumptions of these models are appropriate for cross-sectional count data, they are not capable of taking into account the effect of serial correlation often found in pure time series count data. Real-valued time series models, such as the autoregressive integrated moving average (ARIMA) model, introduced by Box and Jenkins have been used in many applications over the last few decades. However, when modelling non-negative integer-valued data such as traffic accidents at a junction over time, Box and Jenkins models may be inappropriate. This is mainly due to the normality assumption of errors in the ARIMA model. Over the last few years, a new class of time series models known as integer-valued autoregressive (INAR) Poisson models, has been studied by many authors. This class of models is particularly applicable to the analysis of time series count data as these models hold the properties of Poisson regression and able to deal with serial correlation, and therefore offers an alternative to the real-valued time series models. The primary objective of this paper is to introduce the class of INAR models for the time series analysis of traffic accidents in Great Britain. Different types of time series count data are considered: aggregated time series data where both the spatial and temporal units of observation are relatively large (e.g., Great Britain and years) and disaggregated time series data where both the spatial and temporal units are relatively small (e.g., congestion charging zone and months). The performance of the INAR models is compared with the class of Box and

  8. GEN-IV BENCHMARKING OF TRISO FUEL PERFORMANCE MODELS UNDER ACCIDENT CONDITIONS MODELING INPUT DATA

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise Paul [Idaho National Laboratory

    2016-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: • The modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release. • The modeling of the AGR-1 and HFR-EU1bis safety testing experiments. • The comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from “Case 5” of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. “Case 5” of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to “effects of the numerical calculation method rather than the physical model” [IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read

  9. Chernobyl and Fukushima nuclear accidents: what has changed in the use of atmospheric dispersion modeling?

    Science.gov (United States)

    Benamrane, Y; Wybo, J-L; Armand, P

    2013-12-01

    The threat of a major accidental or deliberate event that would lead to hazardous materials emission in the atmosphere is a great cause of concern to societies. This is due to the potential large scale of casualties and damages that could result from the release of explosive, flammable or toxic gases from industrial plants or transport accidents, radioactive material from nuclear power plants (NPPs), and chemical, biological, radiological or nuclear (CBRN) terrorist attacks. In order to respond efficiently to such events, emergency services and authorities resort to appropriate planning and organizational patterns. This paper focuses on the use of atmospheric dispersion modeling (ADM) as a support tool for emergency planning and response, to assess the propagation of the hazardous cloud and thereby, take adequate counter measures. This paper intends to illustrate the noticeable evolution in the operational use of ADM tools over 25 y and especially in emergency situations. This study is based on data available in scientific publications and exemplified using the two most severe nuclear accidents: Chernobyl (1986) and Fukushima (2011). It appears that during the Chernobyl accident, ADM were used few days after the beginning of the accident mainly in a diagnosis approach trying to reconstruct what happened, whereas 25 y later, ADM was also used during the first days and weeks of the Fukushima accident to anticipate the potentially threatened areas. We argue that the recent developments in ADM tools play an increasing role in emergencies and crises management, by supporting stakeholders in anticipating, monitoring and assessing post-event damages. However, despite technological evolutions, its prognostic and diagnostic use in emergency situations still arise many issues.

  10. Modeling of Spray System Operation under Hydrogen and Steam Emissions in NPP Containment during Severe Accident

    Directory of Open Access Journals (Sweden)

    Vadim E. Seleznev

    2011-01-01

    Full Text Available The paper describes one of the variants of mathematical models of a fluid dynamics process inside the containment, which occurs in the conditions of operation of spray systems in severe accidents at nuclear power plant. The source of emergency emissions in this case is the leak of the coolant or rupture at full cross-section of the main circulating pipeline in a reactor building. Leak or rupture characteristics define the localization and the temporal law of functioning of a source of emergency emission (or accrued operating of warmed up hydrogen and steam in the containment. Operation of this source at the course of analyzed accident models should be described by the assignment of the relevant Dirichlet boundary conditions. Functioning of the passive autocatalytic recombiners of hydrogen is described in the form of the complex Newton boundary conditions.

  11. Analysis of the consequences of aircraft manufacturers’ system integration model

    Directory of Open Access Journals (Sweden)

    João Henrique Lopes Guerra

    2013-11-01

    Full Text Available This is a theoretical-conceptual, which aimed to identify some likely consequences of the integration model systems that have been adopted in the aerospace industry by major aircraft manufacturers in the world. In the model of system integration, these manufacturers maintain internally the activities associated with their basic skills and transfer their skills to peripheral suppliers. We identified the following consequences: the growth of strategic alliances in the airline industry, the internationalization of aeronautical chains, with the strengthening of productive activities in some geographic regions; challenges related to the domestic supplier base and the consolidation of national chains, the greatest power suppliers of the first layer, the contribution to the dissemination of knowledge among supply chains, and the potential emergence of new competitors.

  12. Phenomenological and mechanistic modeling of melt-structure-water interactions in a light water reactor severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Bui, V.A

    1998-10-01

    The objective of this work is to address the modeling of the thermal hydrodynamic phenomena and interactions occurring during the progression of reactor severe accidents. Integrated phenomenological models are developed to describe the accident scenarios, which consist of many processes, while mechanistic modeling, including direct numerical simulation, is carried out to describe separate effects and selected physical phenomena of particular importance 88 refs, 54 figs, 7 tabs

  13. Physical Consequences of Nonabelian Duality in the Standard Model

    OpenAIRE

    Chan, H. M.; Tsou, S. T.

    1997-01-01

    Possible physical consequences of a recently discovered nonabelian dual symmetry are explored in the standard model. It is found that both Higgs fields and fermion generations can be assigned a natural place in the dual framework, with Higgs fields appearing as frames (or `N-beins') in internal symmetry space, and generations appearing as spontaneously broken dual colour. Fermions then occur in exactly 3 generations and have a factorizable mass matrix which gives automatically one generation ...

  14. Modeling and Simulation of Release of Radiation in Flow Blockage Accident for Two Loops PWR

    OpenAIRE

    Khurram Mehboob; Cao Xinrong; Majid Ali

    2012-01-01

    In this study modeling and simulation of release of radiation form two loops PWR has been carried out for flow blockage accident. For this purpose, a MATLAB based program “Source Term Evaluator for Flow Blockage Accident” (STEFBA) has been developed, which uses the core inventory as its primary input. The TMI-2 reactor is considered as the reference plant for this study. For 1100 reactor operation days, the core inventory has been evaluated under the core design constrains at average reactor ...

  15. A drug cost model for injuries due to road traffic accidents.

    Directory of Open Access Journals (Sweden)

    Riewpaiboon A

    2008-03-01

    Full Text Available Objective: This study aimed to develop a drug cost model for injuries due to road traffic accidents for patients receiving treatment at a regional hospital in Thailand. Methods: The study was designed as a retrospective, descriptive analysis. The cases were all from road traffic accidents receiving treatment at a public regional hospital in the fiscal year 2004. Results: Three thousand seven hundred and twenty-three road accident patients were included in the study. The mean drug cost per case was USD18.20 (SD=73.49, median=2.36. The fitted drug cost model had an adjusted R2 of 0.449. The positive significant predictor variables of drug costs were prolonged length of stay, age over 30 years old, male, Universal Health Coverage Scheme, time of accident during 18:00-24:00 o’clock, and motorcycle comparing to bus. To forecast the drug budget for 2006, there were two approaches identified, the mean drug cost and the predicted average drug cost. The predicted average drug cost was calculated based on the forecasted values of statistically significant (p<0.05 predictor variables included in the fitted model; predicted total drug cost was USD44,334. Alternatively, based on the mean cost, predicted total drug cost in 2006 was USD63,408. This was 43% higher than the figure based on the predicted cost approach.Conclusions: The planned budget of drug cost based on the mean cost and predicted average cost were meaningfully different. The application of a predicted average cost model could result in a more accurate budget planning than that of a mean statistic approach.

  16. Initial VHTR accident scenario classification: models and data.

    Energy Technology Data Exchange (ETDEWEB)

    Vilim, R. B.; Feldman, E. E.; Pointer, W. D.; Wei, T. Y. C.; Nuclear Engineering Division

    2005-09-30

    Nuclear systems codes are being prepared for use as computational tools for conducting performance/safety analyses of the Very High Temperature Reactor. The thermal-hydraulic codes are RELAP5/ATHENA for one-dimensional systems modeling and FLUENT and/or Star-CD for three-dimensional modeling. We describe a formal qualification framework, the development of Phenomena Identification and Ranking Tables (PIRTs), the initial filtering of the experiment databases, and a preliminary screening of these codes for use in the performance/safety analyses. In the second year of this project we focused on development of PIRTS. Two events that result in maximum fuel and vessel temperatures, the Pressurized Conduction Cooldown (PCC) event and the Depressurized Conduction Cooldown (DCC) event, were selected for PIRT generation. A third event that may result in significant thermal stresses, the Load Change event, is also selected for PIRT generation. Gas reactor design experience and engineering judgment were used to identify the important phenomena in the primary system for these events. Sensitivity calculations performed with the RELAP5 code were used as an aid to rank the phenomena in order of importance with respect to the approach of plant response to safety limits. The overall code qualification methodology was illustrated by focusing on the Reactor Cavity Cooling System (RCCS). The mixed convection mode of heat transfer and pressure drop is identified as an important phenomenon for Reactor Cavity Cooling System (RCCS) operation. Scaling studies showed that the mixed convection mode is likely to occur in the RCCS air duct during normal operation and during conduction cooldown events. The RELAP5/ATHENA code was found to not adequately treat the mixed convection regime. Readying the code will require adding models for the turbulent mixed convection regime while possibly performing new experiments for the laminar mixed convection regime. Candidate correlations for the turbulent

  17. Consequence and Resilience Modeling for Chemical Supply Chains

    Science.gov (United States)

    Stamber, Kevin L.; Vugrin, Eric D.; Ehlen, Mark A.; Sun, Amy C.; Warren, Drake E.; Welk, Margaret E.

    2011-01-01

    The U.S. chemical sector produces more than 70,000 chemicals that are essential material inputs to critical infrastructure systems, such as the energy, public health, and food and agriculture sectors. Disruptions to the chemical sector can potentially cascade to other dependent sectors, resulting in serious national consequences. To address this concern, the U.S. Department of Homeland Security (DHS) tasked Sandia National Laboratories to develop a predictive consequence modeling and simulation capability for global chemical supply chains. This paper describes that capability , which includes a dynamic supply chain simulation platform called N_ABLE(tm). The paper also presents results from a case study that simulates the consequences of a Gulf Coast hurricane on selected segments of the U.S. chemical sector. The case study identified consequences that include impacted chemical facilities, cascading impacts to other parts of the chemical sector. and estimates of the lengths of chemical shortages and recovery . Overall. these simulation results can DHS prepare for and respond to actual disruptions.

  18. Analysis of ex-vessel melt jet breakup and coolability. Part 1: Sensitivity on model parameters and accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, Kiyofumi; Park, Hyun Sun, E-mail: hejsunny@postech.ac.kr; Hwang, Byoungcheol; Jung, Woo Hyun

    2016-06-15

    Highlights: • Application of JASMINE code to melt jet breakup and coolability in APR1400 condition. • Coolability indexes for quasi steady state breakup and cooling process. • Typical case in complete breakup/solidification, film boiling quench not reached. • Significant impact of water depth and melt jet size; weak impact of model parameters. - Abstract: The breakup of a melt jet falling in a water pool and the coolability of the melt particles produced by such jet breakup are important phenomena in terms of the mitigation of severe accident consequences in light water reactors, because the molten and relocated core material is the primary heat source that governs the accident progression. We applied a modified version of the fuel–coolant interaction simulation code, JASMINE, developed at Japan Atomic Energy Agency (JAEA) to a plant scale simulation of melt jet breakup and cooling assuming an ex-vessel condition in the APR1400, a Korean advanced pressurized water reactor. Also, we examined the sensitivity on seven model parameters and five initial/boundary condition variables. The results showed that the melt cooling performance of a 6 m deep water pool in the reactor cavity is enough for removing the initial melt enthalpy for solidification, for a melt jet of 0.2 m initial diameter. The impacts of the model parameters were relatively weak and that of some of the initial/boundary condition variables, namely the water depth and melt jet diameter, were very strong. The present model indicated that a significant fraction of the melt jet is not broken up and forms a continuous melt pool on the containment floor in cases with a large melt jet diameter, 0.5 m, or a shallow water pool depth, ≤3 m.

  19. Hybrid Models Based on Singular Values and Autoregressive Methods for Multistep Ahead Forecasting of Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Lida Barba

    2016-01-01

    Full Text Available The traffic accidents occurrence urges the intervention of researchers and society; the human losses and material damage could be abated with scientific studies focused on supporting prevention plans. In this paper prediction strategies based on singular values and autoregressive models are evaluated for multistep ahead traffic accidents forecasting. Three time series of injured people in traffic accidents collected in Santiago de Chile from 2000:1 to 2014:12 were used, which were previously classified by causes related to the behavior of drivers, passengers, or pedestrians and causes not related to the behavior as road deficiencies, mechanical failures, and undetermined causes. A simplified form of Singular Spectrum Analysis (SSA, combined with the autoregressive linear (AR method, and a conventional Artificial Neural Network (ANN are proposed. Additionally, equivalent models that combine Hankel Singular Value Decomposition (HSVD, AR, and ANN are evaluated. The comparative analysis shows that the hybrid models SSA-AR and SSA-ANN reach the highest accuracy with an average MAPE of 1.5% and 1.9%, respectively, from 1- to 14-step ahead prediction. However, it was discovered that HSVD-AR shows a higher accuracy in the farthest horizons, from 12- to 14-step ahead prediction, which reaches an average MAPE of 2.2%.

  20. THE ROLE OF BELARUS NATIONAL COMMISSION ON RADIATION PROTECTION IN THE MINIMIZATION OF CONSEQUENCES OF THE ACCIDENT AT THE CHERNOBYL NUCLEAR POWER PLANT

    Directory of Open Access Journals (Sweden)

    A. N. Stozharov

    2016-01-01

    Full Text Available The Belarus National Commission on Radiation Protection was established in 1991, based on the former Byelorussian Soviet Socialist Republic Supreme Council Resolution. The Commission works out recommendations on the radiation protection to submit to the state authorities, state institutions under the Republic of Belarus Government and state research institutions, reviews and assesses scientific data in the field of radiation protection and makes suggestions in regards of the implementation of the achieved developments. The Commission engages leading scientists and practitioners from Belarus, involved in the provision of the radiation protection and safety in the state. The methodological cornerstone for the Commission activities was chosen to be the committment to the worldwide accepted approach of the nature and magnitude of the undertaken protective measures justification in the field of radiation safety. The Commission adheres the ALARA optimization criteria as the core of the aforementioned approach. The Commission has also submited to the Government a number of developments which were crucial in the highest level managerial decisions elaboration. The latter impacted directly the state tactics and strategy in the environmental, health and social consequences of the Chernobyl disaster minimization. Following the recommendations of the international institutions (ICRP, IAEA, UNSCEAR, FAO/WHO, developments of the colleagues in the Russian Federation, Ukraine and the local regional experience, the Commission proceeds with the expert observation of the ongoing protective measures to reduce the radiation impact and population exposure resulted from the Chernobyl accident, is actively occupied in the radiation safety ensuring at the Belarussian nuclear power plant being under construction, much contributes to elaboration of the new version of the state Law “On Radiation Protection of Population” and other regulatory documents.

  1. A new CFD modeling method for flow blockage accident investigations

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wenyuan, E-mail: fanwy@mail.ustc.edu.cn; Peng, Changhong, E-mail: pengch@ustc.edu.cn; Chen, Yangli, E-mail: chenyl@mail.ustc.edu.cn; Guo, Yun, E-mail: guoyun79@ustc.edu.cn

    2016-07-15

    Highlights: • Porous-jump treatment is applied to CFD simulation on flow blockages. • Porous-jump treatment predicts consistent results with direct CFD treatment. • Relap5 predicts abnormal flow rate profiles in MTR SFA blockage scenario. • Relap5 fails to simulate annular heat flux in blockage case of annular assembly. • Porous-jump treatment provides reasonable and generalized CFD results. - Abstract: Inlet flow blockages in both flat and annular plate-type fuel assemblies are simulated by (Computational Fluid Dynamics) CFD and system analysis methods, with blockage ratio ranging from 60 to 90%. For all the blockage scenarios, mass flow rate of the blocked channel drops dramatically as blockage ratio increases, while mass flow rates of non-blocked channels are almost steady. As a result of over-simplifications, the system code fails to capture details of mass flow rate profiles of non-blocked channels and power redistribution of fuel plates. In order to acquire generalized CFD results, a new blockage modeling method is developed by using the porous-jump condition. For comparisons, direct CFD simulations are conducted toward postulated blockages. For the porous-jump treatment, conservative flow and heat transfer conditions are predicted for the blocked channel, while consistent predictions are obtained for non-blocked channels. Besides, flow fields in the blocked channel, asymmetric power redistributions of fuel plates, and complex heat transfer phenomena in annular fuel assembly are obtained and discussed. The present study indicates that the porous-jump condition is a reasonable blockage modeling method, which predicts generalized CFD results for flow blockages.

  2. Modelling Hydrological Consequences of Climate Change-Progress and Challenges

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The simulation of hydrological consequences of climate change has received increasing attention from the hydrology and land-surface modelling communities. There have been many studies of climate-change effects on hydrology and water resources which usually consist of three steps: (1) use of general circulation models (GCMs) to provide future global climate scenarios under the effect of increasing greenhouse gases,(2) use of downscaling techniques (both nested regional climate models, RCMs, and statistical methods)for "downscaling" the GCM output to the scales compatible with hydrological models, and (3) use of hydrologic models to simulate the effects of climate change on hydrological regimes at various scales.Great progress has been achieved in all three steps during the past few years, however, large uncertainties still exist in every stage of such study. This paper first reviews the present achievements in this field and then discusses the challenges for future studies of the hydrological impacts of climate change.

  3. Reasoning about causes and consequences in Mulitlevel Flow Models

    DEFF Research Database (Denmark)

    Lind, Morten

    2012-01-01

    -end topology of the multilevel flow models and may be used for design of human machine interfaces supporting diagrammatic reasoning about spatial-temporal aspects of dynamic situations. The principles described in the paper have been used in the implementation of a model based reasoning system.......The purpose of the paper is to describe how multilevel flow models are used for reasoning about causes and consequences in complex dynamic processes. Reasoning in MFM models derives its power from representation of process knowledge on several levels of specification. The detailed specification...... is the basis for implementation of automated model based reasoning functions whereas the more abstract specifica-tions provides generic process knowledge for formulation of reasoning strategies and for giving explanations. Reasoning strategies and explanations can be directly visualized in terms of the means...

  4. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    Science.gov (United States)

    Crider, Dennis; Foster, John V.

    2012-01-01

    In-flight loss of control remains the leading contributor to aviation accident fatalities, with stall upsets being the leading causal factor. The February 12, 2009. Colgan Air, Inc., Continental Express flight 3407 accident outside Buffalo, New York, brought this issue to the forefront of public consciousness and resulted in recommendations from the National Transportation Safety Board to conduct training that incorporates stalls that are fully developed and develop simulator standards to support such training. In 2010, Congress responded to this accident with Public Law 11-216 (Section 208), which mandates full stall training for Part 121 flight operations. Efforts are currently in progress to develop recommendations on implementation of stall training for airline pilots. The International Committee on Aviation Training in Extended Envelopes (ICATEE) is currently defining simulator fidelity standards that will be necessary for effective stall training. These recommendations will apply to all civil transport aircraft including straight-wing turboprop aircraft. Government-funded research over the previous decade provides a strong foundation for stall/post-stall simulation for swept-wing, conventional tail jets to respond to this mandate, but turboprops present additional and unique modeling challenges. First among these challenges is the effect of power, which can provide enhanced flow attachment behind the propellers. Furthermore, turboprops tend to operate for longer periods in an environment more susceptible to ice. As a result, there have been a significant number of turboprop accidents as a result of the early (lower angle of attack) stalls in icing. The vulnerability of turboprop configurations to icing has led to studies on ice accumulation and the resulting effects on flight behavior. Piloted simulations of these effects have highlighted the important training needs for recognition and mitigation of icing effects, including the reduction of stall margins

  5. Development of a Gravid Uterus Model for the Study of Road Accidents Involving Pregnant Women.

    Science.gov (United States)

    Auriault, F; Thollon, L; Behr, M

    2016-01-01

    Car accident simulations involving pregnant women are well documented in the literature and suggest that intra-uterine pressure could be responsible for the phenomenon of placental abruption, underlining the need for a realistic amniotic fluid model, including fluid-structure interactions (FSI). This study reports the development and validation of an amniotic fluid model using an Arbitrary Lagrangian Eulerian formulation in the LS-DYNA environment. Dedicated to the study of the mechanisms responsible for fetal injuries resulting from road accidents, the fluid model was validated using dynamic loading tests. Drop tests were performed on a deformable water-filled container at acceleration levels that would be experienced in a gravid uterus during a frontal car collision at 25 kph. During the test device braking phase, container deformation induced by inertial effects and FSI was recorded by kinematic analysis. These tests were then simulated in the LS-DYNA environment to validate a fluid model under dynamic loading, based on the container deformations. Finally, the coupling between the amniotic fluid model and an existing finite-element full-body pregnant woman model was validated in terms of pressure. To do so, experimental test results performed on four postmortem human surrogates (PMHS) (in which a physical gravid uterus model was inserted) were used. The experimental intra-uterine pressure from these tests was compared to intra uterine pressure from a numerical simulation performed under the same loading conditions. Both free fall numerical and experimental responses appear strongly correlated. The relationship between the amniotic fluid model and pregnant woman model provide intra-uterine pressure values correlated with the experimental test responses. The use of an Arbitrary Lagrangian Eulerian formulation allows the analysis of FSI between the amniotic fluid and the gravid uterus during a road accident involving pregnant women.

  6. Catastrophe model for the exposure to blood-borne pathogens and other accidents in health care settings.

    Science.gov (United States)

    Guastello, S J; Gershon, R R; Murphy, L R

    1999-11-01

    Catastrophe models, which describe and predict discontinuous changes in system state variables, were used to model the exposure to blood and bodily fluids and more conventional occupational accidents among 1708 health care workers. Workers at three hospitals completed a survey measuring HIV-relevant exposures (needlesticks, cuts, splashes, contact with open wounds), the accident rate for broadly-defined injuries, and several occupationally relevant themes: safety climate, shift work, depression symptoms, work pace, verbal abuse, and professional group membership. A cusp (cubic polynomial) model predicting HIV-relevant exposures specifically was more accurate (R2 = 0.56) than a comparable linear model containing the same variables (R2 = 0.07). Some of the foregoing variables predisposed workers to greater differences in HIV-relevant and general accident exposures: shiftwork, climate, depressive symptoms, and work pace. Other variables governed how close an individual was to a critical threshold where a harmful incident would take place: verbal abuse, professional group membership. Similarly, a cusp model for accident incidents predicted from HIV-relevant exposures and occupational variables was also more accurate (R2 = 0.75) than comparison models. Two variables predisposed the worker to a greater accident risk: depression symptoms and shift work. Four other variables predisposed the worker to lesser accident risk: job satisfaction, safety climate, environmental stressors, and work pace. Compliance with the universal precautions and HIV-related training were not relevant to either of the models.

  7. The Application of Data Mining Technology to Build a Forecasting Model for Classification of Road Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Yau-Ren Shiau

    2015-01-01

    Full Text Available With the ever-increasing number of vehicles on the road, traffic accidents have also increased, resulting in the loss of lives and properties, as well as immeasurable social costs. The environment, time, and region influence the occurrence of traffic accidents. The life and property loss is expected to be reduced by improving traffic engineering, education, and administration of law and advocacy. This study observed 2,471 traffic accidents which occurred in central Taiwan from January to December 2011 and used the Recursive Feature Elimination (RFE of Feature Selection to screen the important factors affecting traffic accidents. It then established models to analyze traffic accidents with various methods, such as Fuzzy Robust Principal Component Analysis (FRPCA, Backpropagation Neural Network (BPNN, and Logistic Regression (LR. The proposed model aims to probe into the environments of traffic accidents, as well as the relationships between the variables of road designs, rule-violation items, and accident types. The results showed that the accuracy rate of classifiers FRPCA-BPNN (85.89% and FRPCA-LR (85.14% combined with FRPCA is higher than that of BPNN (84.37% and LR (85.06% by 1.52% and 0.08%, respectively. Moreover, the performance of FRPCA-BPNN and FRPCA-LR combined with FRPCA in classification prediction is better than that of BPNN and LR.

  8. Modelling road accident blackspots data with the discrete generalized Pareto distribution.

    Science.gov (United States)

    Prieto, Faustino; Gómez-Déniz, Emilio; Sarabia, José María

    2014-10-01

    This study shows how road traffic networks events, in particular road accidents on blackspots, can be modelled with simple probabilistic distributions. We considered the number of crashes and the number of fatalities on Spanish blackspots in the period 2003-2007, from Spanish General Directorate of Traffic (DGT). We modelled those datasets, respectively, with the discrete generalized Pareto distribution (a discrete parametric model with three parameters) and with the discrete Lomax distribution (a discrete parametric model with two parameters, and particular case of the previous model). For that, we analyzed the basic properties of both parametric models: cumulative distribution, survival, probability mass, quantile and hazard functions, genesis and rth-order moments; applied two estimation methods of their parameters: the μ and (μ+1) frequency method and the maximum likelihood method; used two goodness-of-fit tests: Chi-square test and discrete Kolmogorov-Smirnov test based on bootstrap resampling; and compared them with the classical negative binomial distribution in terms of absolute probabilities and in models including covariates. We found that those probabilistic models can be useful to describe the road accident blackspots datasets analyzed.

  9. Application of Gray Markov SCGM(1,1) c Model to Prediction of Accidents Deaths in Coal Mining.

    Science.gov (United States)

    Lan, Jian-Yi; Zhou, Ying

    2014-01-01

    The prediction of mine accident is the basis of aviation safety assessment and decision making. Gray prediction is suitable for such kinds of system objects with few data, short time, and little fluctuation, and Markov chain theory is just suitable for forecasting stochastic fluctuating dynamic process. Analyzing the coal mine accident human error cause, combining the advantages of both Gray prediction and Markov theory, an amended Gray Markov SCGM(1,1) c model is proposed. The gray SCGM(1,1) c model is applied to imitate the development tendency of the mine safety accident, and adopt the amended model to improve prediction accuracy, while Markov prediction is used to predict the fluctuation along the tendency. Finally, the new model is applied to forecast the mine safety accident deaths from 1990 to 2010 in China, and, 2011-2014 coal accidents deaths were predicted. The results show that the new model not only discovers the trend of the mine human error accident death toll but also overcomes the random fluctuation of data affecting precision. It possesses stronger engineering application.

  10. Lessons from Chernobyl and prognosis for Fukushima: radiological consequences.

    Science.gov (United States)

    Ivanov, Victor K

    2012-03-01

    The following are considered: results of large-scale radiation epidemiological studies of the health effects of the Chernobyl accident, radiation risks for emergency workers and the affected population; and verification of ICRP risk models taking into account data on the Chernobyl accident and preliminary prognostic estimates of potential radiological consequences of the Fukushima disaster.

  11. Validation of advanced NSSS simulator model for loss-of-coolant accidents

    Energy Technology Data Exchange (ETDEWEB)

    Kao, S.P.; Chang, S.K.; Huang, H.C. [Nuclear Training Branch, Northeast Utilities, Waterford, CT (United States)

    1995-09-01

    The replacement of the NSSS (Nuclear Steam Supply System) model on the Millstone 2 full-scope simulator has significantly increased its fidelity to simulate adverse conditions in the RCS. The new simulator NSSS model is a real-time derivative of the Nuclear Plant Analyzer by ABB. The thermal-hydraulic model is a five-equation, non-homogeneous model for water, steam, and non-condensible gases. The neutronic model is a three-dimensional nodal diffusion model. In order to certify the new NSSS model for operator training, an extensive validation effort has been performed by benchmarking the model performance against RELAP5/MOD2. This paper presents the validation results for the cases of small-and large-break loss-of-coolant accidents (LOCA). Detailed comparisons in the phenomena of reflux-condensation, phase separation, and two-phase natural circulation are discussed.

  12. Modeling the consequences of tongue surgery on tongue mobility

    CERN Document Server

    Buchaillard, Stéphanie; Perrier, Pascal; Payan, Yohan

    2007-01-01

    This paper presents the current achievements of a long term project aiming at predicting and assessing the impact of tongue and mouth floor surgery on tongue mobility. The ultimate objective of this project is the design of a software with which surgeons should be able (1) to design a 3D biomechanical model of the tongue and of the mouth floor that matches the anatomical characteristics of each patient specific oral cavity, (2) to simulate the anatomical changes induced by the surgery and the possible reconstruction, and (3) to quantitatively predict and assess the consequences of these anatomical changes on tongue mobility and speech production after surgery.

  13. Jet fire consequence modeling for high-pressure gas pipelines

    Science.gov (United States)

    Coccorullo, Ivano; Russo, Paola

    2016-12-01

    A simple and reliable approach for sizing the hazard area potentially affected by a jet fire as consequence of the failure of high-pressure pipeline is proposed. A release rate model, taking pipeline operation properties and source release properties into account, is coupled with SLAB dispersion model and point source radiation model to calculate the hazard distance. The hazard distance is set beyond the distance at which a low chance of fatality can occur to people exposed and a wooden structure is not expected to burn due to radiation heat of jet fire. The comparison between three gases with different physico-chemical properties (i.e. natural gas, hydrogen, ethylene) is shown. The influence of pipeline operating parameters, such as: pressure, pipeline diameter and length, hole size, on the hazard area for the three gases is evaluated. Finally, a simple correlation is proposed for calculating the hazard distance as function of these parameters.

  14. ASTEC V2 severe accident integral code main features, current V2.0 modelling status, perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Chatelard, P., E-mail: patrick.chatelard@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, B.250, Cadarache BP3 13115, Saint-Paul-lez-Durance, Cedex (France); Reinke, N.; Arndt, S. [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50677 Köln (Germany); Belon, S.; Cantrel, L.; Carenini, L.; Chevalier-Jabet, K.; Cousin, F. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, B.250, Cadarache BP3 13115, Saint-Paul-lez-Durance, Cedex (France); Eckel, J. [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50677 Köln (Germany); Jacq, F.; Marchetto, C.; Mun, C.; Piar, L. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, B.250, Cadarache BP3 13115, Saint-Paul-lez-Durance, Cedex (France)

    2014-06-01

    The severe accident integral code ASTEC, jointly developed since almost 20 years by IRSN and GRS, simulates the behaviour of a whole nuclear power plant under severe accident conditions, including severe accident management by engineering systems and procedures. Since 2004, the ASTEC code is progressively becoming the reference European severe accident integral code through in particular the intensification of research activities carried out in the frame of the SARNET European network of excellence. The first version of the new series ASTEC V2 was released in 2009 to about 30 organizations worldwide and in particular to SARNET partners. With respect to the previous V1 series, this new V2 series includes advanced core degradation models (issued from the ICARE2 IRSN mechanistic code) and necessary extensions to be applicable to Gen. III reactor designs, notably a description of the core catcher component to simulate severe accidents transients applied to the EPR reactor. Besides these two key-evolutions, most of the other physical modules have also been improved and ASTEC V2 is now coupled to the SUNSET statistical tool to make easier the uncertainty and sensitivity analyses. The ASTEC models are today at the state of the art (in particular fission product models with respect to source term evaluation), except for quenching of a severely damage core. Beyond the need to develop an adequate model for the reflooding of a degraded core, the main other mean-term objectives are to further progress on the on-going extension of the scope of application to BWR and CANDU reactors, to spent fuel pool accidents as well as to accidents in both the ITER Fusion facility and Gen. IV reactors (in priority on sodium-cooled fast reactors) while making ASTEC evolving towards a severe accident simulator constitutes the main long-term objective. This paper presents the status of the ASTEC V2 versions, focussing on the description of V2.0 models for water-cooled nuclear plants.

  15. Analysis 320 coal mine accidents using structural equation modeling with unsafe conditions of the rules and regulations as exogenous variables.

    Science.gov (United States)

    Zhang, Yingyu; Shao, Wei; Zhang, Mengjia; Li, Hejun; Yin, Shijiu; Xu, Yingjun

    2016-07-01

    Mining has been historically considered as a naturally high-risk industry worldwide. Deaths caused by coal mine accidents are more than the sum of all other accidents in China. Statistics of 320 coal mine accidents in Shandong province show that all accidents contain indicators of "unsafe conditions of the rules and regulations" with a frequency of 1590, accounting for 74.3% of the total frequency of 2140. "Unsafe behaviors of the operator" is another important contributory factor, which mainly includes "operator error" and "venturing into dangerous places." A systems analysis approach was applied by using structural equation modeling (SEM) to examine the interactions between the contributory factors of coal mine accidents. The analysis of results leads to three conclusions. (i) "Unsafe conditions of the rules and regulations," affect the "unsafe behaviors of the operator," "unsafe conditions of the equipment," and "unsafe conditions of the environment." (ii) The three influencing factors of coal mine accidents (with the frequency of effect relation in descending order) are "lack of safety education and training," "rules and regulations of safety production responsibility," and "rules and regulations of supervision and inspection." (iii) The three influenced factors (with the frequency in descending order) of coal mine accidents are "venturing into dangerous places," "poor workplace environment," and "operator error."

  16. Biogeochemical versus ecological consequences of modeled ocean physics

    Science.gov (United States)

    Clayton, Sophie; Dutkiewicz, Stephanie; Jahn, Oliver; Hill, Christopher; Heimbach, Patrick; Follows, Michael J.

    2017-06-01

    We present a systematic study of the differences generated by coupling the same ecological-biogeochemical model to a 1°, coarse-resolution, and 1/6°, eddy-permitting, global ocean circulation model to (a) biogeochemistry (e.g., primary production) and (b) phytoplankton community structure. Surprisingly, we find that the modeled phytoplankton community is largely unchanged, with the same phenotypes dominating in both cases. Conversely, there are large regional and seasonal variations in primary production, phytoplankton and zooplankton biomass. In the subtropics, mixed layer depths (MLDs) are, on average, deeper in the eddy-permitting model, resulting in higher nutrient supply driving increases in primary production and phytoplankton biomass. In the higher latitudes, differences in winter mixed layer depths, the timing of the onset of the spring bloom and vertical nutrient supply result in lower primary production in the eddy-permitting model. Counterintuitively, this does not drive a decrease in phytoplankton biomass but results in lower zooplankton biomass. We explain these similarities and differences in the model using the framework of resource competition theory, and find that they are the consequence of changes in the regional and seasonal nutrient supply and light environment, mediated by differences in the modeled mixed layer depths. Although previous work has suggested that complex models may respond chaotically and unpredictably to changes in forcing, we find that our model responds in a predictable way to different ocean circulation forcing, despite its complexity. The use of frameworks, such as resource competition theory, provides a tractable way to explore the differences and similarities that occur. As this model has many similarities to other widely used biogeochemical models that also resolve multiple phytoplankton phenotypes, this study provides important insights into how the results of running these models under different physical conditions

  17. Consequence modelling of gas explosion scenarios in traffic tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den; Rhijnsburger, M.P.M.; Doormaal, J.C.A.M. van

    2002-01-01

    In the Netherlands, future road and rail infrastructure is increasingly projected underground or covered in. In this respect, a particular problem shows up with regard to the transportation hazardous materials, witness the many recent severe accidents in European traffic tunnels. Within the entire s

  18. Consequence modelling of gas explosion scenarios in traffic tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den; Rhijnsburger, M.P.M.; Doormaal, J.C.A.M. van

    2002-01-01

    In the Netherlands, future road and rail infrastructure is increasingly projected underground or covered in. In this respect, a particular problem shows up with regard to the transportation hazardous materials, witness the many recent severe accidents in European traffic tunnels. Within the entire s

  19. Interactive Rapid Dose Assessment Model (IRDAM): reactor-accident assessment methods. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness, the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This document describes the technical bases for IRDAM including methods, models and assumptions used in calculations. IRDAM calculates whole body (5-cm depth) and infant thyroid doses at six fixed downwind distances between 500 and 20,000 meters. Radionuclides considered primarily consist of noble gases and radioiodines. In order to provide a rapid assessment capability consistent with the capacity of the Osborne-1 computer, certain simplifying approximations and assumptions are made. These are described, along with default values (assumptions used in the absence of specific input) in the text of this document. Two companion volumes to this one provide additional information on IRDAM. The user's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios.

  20. A re-parameterisation of the Power Model of the relationship between the speed of traffic and the number of accidents and accident victims.

    Science.gov (United States)

    Elvik, Rune

    2013-01-01

    This paper presents a re-analysis of the Power Model of the relationship between the mean speed of traffic and road safety. Past evaluations of the model, most recently in 2009, have broadly speaking supported it. However, the most recent evaluation of the model indicated that the relationship between speed and road safety depends not only on the relative change in speed, as suggested by the Power Model, but also on initial speed. This implies that the exponent describing, for example, a 25% reduction in speed will not be the same when speed changes from 100km/h to 75km/h as it will when speed changes from 20km/h to 15km/h. This paper reports an analysis leading to a re-parameterisation of the Power Model in terms of continuously varying exponents which depend on initial speed. The re-parameterisation was accomplished by fitting exponential functions to data points in which changes in speed and accidents were sorted in groups of 10km/h according to initial speed, starting with data points referring to the highest initial speeds. The exponential functions fitted the data extremely well and imply that the effect on accidents of a given relative change in speed is largest when initial speed is highest. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Igneous Consequence Modeling for the TSPA-SR

    Energy Technology Data Exchange (ETDEWEB)

    John McCord

    2001-10-29

    The purpose of this technical report is to develop credible, defendable, substantiated models for the consequences of igneous activity for the TSPA-SR Model. The effort will build on the TSPA-VA and improve the quality of scenarios and depth of the technical basis underlying disruptive events modeling. Computational models for both volcanic eruptive releases (this is an event that results in ash containing waste being ejected from Yucca Mountain) and igneous intrusion groundwater releases (this is an event that reaches the repository level, impacts the waste packages, and produces releases from waste packages damaged by igneous activity) will be included directly in the TSPA calculations as part of the TSPA-SR Model. This Analysis Model Report (AMR) is limited to development of the conceptual models for these two scenarios. The mathematical implementation of these conceptual models will be done within the TSPA-SR Model. Thus, this AMR will not include any model results or sensitivity analyses. Calculation of any doses resulting from igneous releases will also be done within the TSPA-SR model, as will the probabilistic weighting of these doses. Calculation and analysis of the TSPA-SR Model results for igneous disruption are, therefore, outside the scope of this activity. The reason for not running the mathematical models as part of this AMR is that the models are integrated within the TSPA-SR model and, thus, any model simulations and the corresponding results are out of the scope of this AMR. The scope of this work as defined in the development plan (CRWMS M&O 2000j) involves using data that has been extracted from existing sources to design and support the TSPA-SR models for the transport of radionuclides following igneous disruption of the repository. The development plan states ''applications of the code in this analysis will be limited to testing of the code and sensitivity analyses during analysis design.'' In contrast to the development

  2. Forecasting consequences of accidental release: how reliable are current assessment models

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

    This paper focuses on uncertainties in model output used to assess accidents. We begin by reviewing the historical development of assessment models and the associated interest in uncertainties as these evolutionary processes occurred in the United States. This is followed by a description of the sources of uncertainties in assessment calculations. Types of models appropriate for assessment of accidents are identified. A summary of results from our analysis of uncertainty is provided in results obtained with current methodology for assessing routine and accidental radionuclide releases to the environment. We conclude with discussion of preferred procedures and suggested future directions to improve the state-of-the-art of radiological assessments.

  3. Ecological consequences of global bifurcations in some food chain models.

    Science.gov (United States)

    van Voorn, George A K; Kooi, Bob W; Boer, Martin P

    2010-08-01

    Food chain models of ordinary differential equations (ode's) are often used in ecology to gain insight in the dynamics of populations of species, and the interactions of these species with each other and their environment. One powerful analysis technique is bifurcation analysis, focusing on the changes in long-term (asymptotic) behaviour under parameter variation. For the detection of local bifurcations there exists standardised software, but until quite recently most software did not include any capabilities for the detection and continuation of global bifurcations. We focus here on the occurrence of global bifurcations in four food chain models, and discuss the implications of their occurrence. In two stoichiometric models (one piecewise continuous, one smooth) there exists a homoclinic bifurcation, that results in the disappearance of a limit cycle attractor. Instead, a stable positive equilibrium becomes the global attractor. The models are also capable of bistability. In two three-dimensional models a Shil'nikov homoclinic bifurcation functions as the organising centre of chaos, while tangencies of homoclinic cycle-to-cycle connections 'cut' the chaotic attractors, which is associated with boundary crises. In one model this leads to extinction of the top predator, while in the other model hysteresis occurs. The types of ecological events occurring because of a global bifurcation will be categorized. Global bifurcations are always catastrophic, leading to the disappearance or merging of attractors. However, there is no 1-on-1 coupling between global bifurcation type and the possible ecological consequences. This only emphasizes the importance of including global bifurcations in the analysis of food chain models.

  4. 日本福岛第一核电站事故源项及后果评价%Fukushima Daiichi NPS Accident Source Term and Consequence Assessment

    Institute of Scientific and Technical Information of China (English)

    王海洋; 黄树明; 王晓霞; 尤伟; 米爱军; 张普忠

    2011-01-01

    根据已有的日本福岛第一核电站相关资料,利用美国核管理委员会《轻水堆核电厂事故源项》中的假设条件,计算出事故后安全壳内的放射性源项,综合考虑各种不确定性因素,得出较为保守的环境释放源项。采用美国核管理委员会RG 1.4中大气扩散模式的假设计算大气弥散因子,并应用ICRP 71号出版物F、GR 12号报告等资料中的剂量计算模式及剂量转换因子进行了事故剂量后果的估算、分析和评价。%Conservative source term of radioactive release to the environment is calculated after the accident at Fukushima Daiichi nuclear power station based on updated informational materials and the assumptions made in NUREG-1465 by U.S.Nuclear Regulatory Commission(U.S.NRC),with the consideration of the various uncertainties.And a series of atmospheric dispersion factors are obtained from U.S.NRC Regulatory Guide 1.4(RG 1.4).Finally,this paper provides calculation of the accidental dose,which is analyzed and assessed specifically,using the models and parameters in ICRP Publication 71,FGR 12 and so on.

  5. A combined M5P tree and hazard-based duration model for predicting urban freeway traffic accident durations.

    Science.gov (United States)

    Lin, Lei; Wang, Qian; Sadek, Adel W

    2016-06-01

    The duration of freeway traffic accidents duration is an important factor, which affects traffic congestion, environmental pollution, and secondary accidents. Among previous studies, the M5P algorithm has been shown to be an effective tool for predicting incident duration. M5P builds a tree-based model, like the traditional classification and regression tree (CART) method, but with multiple linear regression models as its leaves. The problem with M5P for accident duration prediction, however, is that whereas linear regression assumes that the conditional distribution of accident durations is normally distributed, the distribution for a "time-to-an-event" is almost certainly nonsymmetrical. A hazard-based duration model (HBDM) is a better choice for this kind of a "time-to-event" modeling scenario, and given this, HBDMs have been previously applied to analyze and predict traffic accidents duration. Previous research, however, has not yet applied HBDMs for accident duration prediction, in association with clustering or classification of the dataset to minimize data heterogeneity. The current paper proposes a novel approach for accident duration prediction, which improves on the original M5P tree algorithm through the construction of a M5P-HBDM model, in which the leaves of the M5P tree model are HBDMs instead of linear regression models. Such a model offers the advantage of minimizing data heterogeneity through dataset classification, and avoids the need for the incorrect assumption of normality for traffic accident durations. The proposed model was then tested on two freeway accident datasets. For each dataset, the first 500 records were used to train the following three models: (1) an M5P tree; (2) a HBDM; and (3) the proposed M5P-HBDM, and the remainder of data were used for testing. The results show that the proposed M5P-HBDM managed to identify more significant and meaningful variables than either M5P or HBDMs. Moreover, the M5P-HBDM had the lowest overall mean

  6. Mesoscale modelling of radioactive contamination formation in Ukraine caused by the Chernobyl accident.

    Science.gov (United States)

    Talerko, Nikolai

    2005-01-01

    This work is devoted to the reconstruction of time-dependent radioactive contamination fields in the territory of Ukraine in the initial period of the Chernobyl accident using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The modelling results were compared with available 137Cs air and ground contamination measurement data. The 137Cs atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The detailed scenario of the release from the accidental unit of the Chernobyl nuclear plant has been built (including time-dependent radioactivity release intensity and time-varied height of the release). The calculations have enabled to explain the main features of spatial and temporal variations of radioactive contamination fields over the territory of Ukraine on the regional scale, including the formation of the major large-scale spots of radioactive contamination caused by dry and wet deposition.

  7. Mesoscale modelling of radioactive contamination formation in Ukraine caused by the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Talerko, Nikolai [Scientific Center for Radiation Medicine, 53 Melnikov Street, Kyiv 04050 (Ukraine)]. E-mail: nick@rpi.kiev.ua

    2005-03-01

    This work is devoted to the reconstruction of time-dependent radioactive contamination fields in the territory of Ukraine in the initial period of the Chernobyl accident using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The modelling results were compared with available {sup 137}Cs air and ground contamination measurement data. The {sup 137}Cs atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The detailed scenario of the release from the accidental unit of the Chernobyl nuclear plant has been built (including time-dependent radioactivity release intensity and time-varied height of the release). The calculations have enabled to explain the main features of spatial and temporal variations of radioactive contamination fields over the territory of Ukraine on the regional scale, including the formation of the major large-scale spots of radioactive contamination caused by dry and wet deposition.

  8. Low-power and shutdown models for the accident sequence precursor (ASP) program

    Energy Technology Data Exchange (ETDEWEB)

    Sattison, M.B.; Thatcher, T.A.; Knudsen, J.K. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1997-02-01

    The US Nuclear Regulatory Commission (NRC) has been using full-power. Level 1, limited-scope risk models for the Accident Sequence Precursor (ASP) program for over fifteen years. These models have evolved and matured over the years, as have probabilistic risk assessment (PRA) and computer technologies. Significant upgrading activities have been undertaken over the past three years, with involvement from the Offices of Nuclear Reactor Regulation (NRR), Analysis and Evaluation of Operational Data (AEOD), and Nuclear Regulatory Research (RES), and several national laboratories. Part of these activities was an RES-sponsored feasibility study investigating the ability to extend the ASP models to include contributors to core damage from events initiated with the reactor at low power or shutdown (LP/SD), both internal events and external events. This paper presents only the LP/SD internal event modeling efforts.

  9. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  10. Overview of cost-consequence modeling in outcomes research.

    Science.gov (United States)

    Stergachis, A

    1995-01-01

    Outcomes research has developed in response to the need for information on costs, risks, and benefits of clinical treatments, including data regarding the effectiveness of prescription drugs. It attempts to consider more than the biologic effects of pharmaceuticals, that is, to encompass wider measures of the results of their use, issues that are not routinely addressed during clinical trials. Cost-effectiveness analysis compares the outcome of different treatment options in terms of monetary cost per unit of effectiveness. Examples of measures of effectiveness are years of life saved, number of days of hospitalization avoided, and number of treatment successes. Cost-consequence models, also referred to as cost-outcome models, deal with costs and a variety of outcomes ranging from clinical to humanistic. Direct medical costs are those for prevention, detection, treatment, and rehabilitation; they are amounts spent to treat an illness, including hospitalization, professional services, pharmaceuticals, and medical supplies. Indirect medical costs are associated with changes in productivity, such as earnings lost because of illness. Humanistic outcomes deal primarily with functional status, quality of life, and satisfaction, and may include pain, anxiety, self-esteem, ability to carry out normal activities, and overall impressions. Since it is not possible to study all effects of treatments with clinical trials, modeling techniques are useful in making therapeutic decisions.

  11. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Heames, T.J. (Science Applications International Corp., Albuquerque, NM (USA)); Williams, D.A.; Johns, N.A.; Chown, N.M. (UKAEA Atomic Energy Establishment, Winfrith (UK)); Bixler, N.E.; Grimley, A.J. (Sandia National Labs., Albuquerque, NM (USA)); Wheatley, C.J. (UKAEA Safety and Reliability Directorate, Culcheth (UK))

    1990-10-01

    This document provides a description of a model of the radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident. This document serves as the user's manual for the computer code called VICTORIA, based upon the model. The VICTORIA code predicts fission product release from the fuel, chemical reactions between fission products and structural materials, vapor and aerosol behavior, and fission product decay heating. This document provides a detailed description of each part of the implementation of the model into VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided. The VICTORIA code was developed upon a CRAY-XMP at Sandia National Laboratories in the USA and a CRAY-2 and various SUN workstations at the Winfrith Technology Centre in England. 60 refs.

  12. A Study of The Relationship Between The Components of The Five-Factor Model of Personality and The Occurrence of Occupational Accidents in Industry Workers

    Directory of Open Access Journals (Sweden)

    Ehsanollah Habibi

    2016-05-01

    Full Text Available Accidents are among the most important problems of both the developed and the developing countries. Individual factors and personality traits are the primary causes of human errors and contribute to accidents. The present study aims to investigate the relationship between the components of the five-factor model of personality and the occurrence of occupational accidents in industrial workers. The independent T-test indicated that there is a meaningful relationship between the personality traits and accident proneness. In the two groups of industry workers injured in occupational accidents and industry workers without any occupational accidents, there is a significant relationship between personality traits, neuroticism (p=0.001, openness to experience (p=0.001, extraversion (p=0.024 and conscientiousness (p=0.021. Nonetheless, concerning the personality trait of agreeableness (p = 0.09, the group of workers with accidents did not differ significantly from the workers without any accidents. The results showed that there is a direct and significant relationship between accident proneness and the personality traits of neuroticism and openness to experience. Furthermore, there is a meaningful but inverse correlation between accident proneness and the personality traits of extraversion and conscientiousness, while there was no relationship between accident proneness and the personality trait of agreeableness.

  13. What are the consequences of the reactor accident in Fukushima for the evaluation of nuclear risk?; Welche Folgen hat der Kernkraftwerksunfall in Fukushima fuer die Bewertung von Kernenergierisiken?

    Energy Technology Data Exchange (ETDEWEB)

    Renn, Ortwin [Univ. Stuttgart (Germany). Inst. Sozialwissenshaften V; Gallego Carrera, Diana [Univ. Stuttgart (Germany). ZIRIUS Zentrum fuer Interdiszipliaere Risiko- und Innovationsforschung

    2015-06-01

    There are historical breaks in the relation of risk analysis, risk perception and regulation policy. The year 2011 with the reactor accident in the NPP Fukushima was such a break, especially in Germany. The nuclear phase-out was reduced to ten years the energy policy turnaround received a broad societal agreement. Nuclear facilities loose public acceptance, the risk perception has changed. The Japanese evaluation results on faulty and nontransparent behavior and the lack of governance of responsible persons and authorities including a poor accident management have further decreased the public confidence. A new concept of safety culture for all nuclear facilities including the radioactive waste management is required, the communication processes between plant operator, authorities, science and the public have to be intensified.

  14. IMMEDIATE MENTAL CONSEQUENCES OF THE GREAT EAST JAPAN EARTHQUAKE AND FUKUSHIMA NUCLEAR POWER PLANT ACCIDENT ON MOTHERS EXPERIENCING MISCARRIAGE, ABORTION, AND STILLBIRTH: THE FUKUSHIMA HEALTH MANAGEMENT SURVEY

    OpenAIRE

    Yoshida-Komiya, Hiromi; Goto, Aya; Yasumura, Seiji; FUJIMORI, KEIYA; Abe, Masafumi; FOR THE PREGNANCY AND BIRTH SURVEY GROUP OF THE FUKUSHIMA HEALTH MANAGEMENT SURVEY,

    2015-01-01

    Background: The Fukushima Pregnancy and Birth Survey was launched to monitor pregnant mothers’ health after the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant (NPP) accident. Several lines of investigations have indicated that a disaster impacts maternal mental health with childbirth. However, there is no research regarding mental health of mothers with fetal loss after a disaster. In this report, we focus on those women immediately after the Great East Japan Earthquake...

  15. Immediate mental consequences of the great east Japan earthquake and Fukushima nuclear power Plant accident on mothers experiencing miscarriage, abortion, and stillbirth: the Fukushima health management survey

    OpenAIRE

    YOSHIDA-KOMIYA, HIROMI; Goto, Aya; Yasumura, Seiji; FUJIMORI, KEIYA; Abe, Masafumi

    2015-01-01

    Background: The Fukushima Pregnancy and Birth Survey was launched to monitor pregnant mothers' health after the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant (NPP) accident. Several lines of investigations have indicated that a disaster impacts maternal mental health with childbirth. However, there is no research regarding mental health of mothers with fetal loss after a disaster. In this report, we focus on those women immediately after the Great East Japan Earthquake...

  16. A source term estimation method for a nuclear accident using atmospheric dispersion models

    DEFF Research Database (Denmark)

    Kim, Minsik; Ohba, Ryohji; Oura, Masamichi

    2015-01-01

    The objective of this study is to develop an operational source term estimation (STE) method applicable for a nuclear accident like the incident that occurred at the Fukushima Dai-ichi nuclear power station in 2011. The new STE method presented here is based on data from atmospheric dispersion...... models and short-range observational data around the nuclear power plants.The accuracy of this method is validated with data from a wind tunnel study that involved a tracer gas release from a scaled model experiment at Tokai Daini nuclear power station in Japan. We then use the methodology developed...... and validated through the effort described in this manuscript to estimate the release rate of radioactive material from the Fukushima Dai-ichi nuclear power station....

  17. Ruthenium release modelling in air under severe accident conditions using the MAAP4 code

    Energy Technology Data Exchange (ETDEWEB)

    Beuzet, E.; Lamy, J.S. [EDF R and D, 1 avenue du General de Gaulle, F-92140 Clamart (France); Perron, H. [EDF R and D, Avenue des Renardieres, Ecuelles, F-77818 Moret sur Loing (France); Simoni, E. [Institut de Physique Nucleaire, Universite de Paris Sud XI, F-91406 Orsay (France)

    2010-07-01

    In a nuclear power plant (NPP), in some situations of low probability of severe accidents, an air ingress into the vessel occurs. Air is a highly oxidizing atmosphere that can lead to an enhanced core degradation affecting the release of Fission Products (FPs) to the environment (source term). Indeed, Zircaloy-4 cladding oxidation by air yields 85% more heat than by steam. Besides, UO{sub 2} can be oxidised to UO{sub 2+x} and mixed with Zr, which may lead to a decrease of the fuel melting temperature. Finally, air atmosphere can enhance the FPs release, noticeably that of ruthenium. Ruthenium is of particular interest for two main reasons: first, its high radiotoxicity due to its short and long half-life isotopes ({sup 103}Ru and {sup 106}Ru respectively) and second, its ability to form highly volatile compounds such as ruthenium gaseous tetra-oxide (RuO{sub 4}). Considering that the oxygen affinity decreases between cladding, fuel and ruthenium inclusions, it is of great need to understand the phenomena governing fuel oxidation by air and ruthenium release as prerequisites for the source term issues. A review of existing data on ruthenium release, controlled by fuel oxidation, leads us to implement a new model in the EDF version of MAAP4 severe accident code (Modular Accident Analysis Program). This model takes into account the fuel stoichiometric deviation and the oxygen partial pressure evolution inside the fuel to simulate its oxidation by air. Ruthenium is then oxidised. Its oxides are released by volatilisation above the fuel. All the different ruthenium oxides formed and released are taken into consideration in the model, in terms of their particular reaction constants. In this way, partial pressures of ruthenium oxides are given in the atmosphere so that it is possible to know the fraction of ruthenium released in the atmosphere. This new model has been assessed against an analytical test of FPs release in air atmosphere performed at CEA (VERCORS RT8). The

  18. Effect of Check Valve on Consequences of Coolant Pump Rotor Seizure Accident for EPR Reactor%止回阀对EPR反应堆主泵卡轴事故后果的影响

    Institute of Scientific and Technical Information of China (English)

    陈秋炀; 周拥辉

    2012-01-01

    分析计算欧洲先进压水堆(EPR)反应堆主泵卡轴事故,并对比在主泵出口安装止回阀和没有安装止回阀模型的卡轴事故安全分析.结果表明,在EPR主泵卡轴事故中,止回阀可增加模型堆芯进口流量约4%,有利于堆芯的冷却.止回阀可显著地提高堆芯最小偏离泡核沸腾比(DNBR),降低堆芯偏离泡核沸腾(DNB)份额,降低包壳温度约14℃.模型分析结果表明,在主泵卡轴事故工况下,主泵出口安装止回阀可更好地维持堆芯的完整性.%Counter current flow phenomenon would appear during reactor coolant pump rotor seizure accident. Present work analyzes the coolant pump rotor seizure accident for European Pressurized Reactor (EPR). The accident safety analysis results of model with check valve and without check valve are compared. It can be found that the check valve can increase the core inlet flow rate of model about 4%. The increasing of coolant flow rate is beneficial to the reactor core cooling. Check valve can increase the minimum departure from nucleate boiling ratio (DNBR), reduce the departure from nucleate boiling (DNB) fraction and the fuel rod cladding temperature about 14℃ during coolant pump rotor seizure accident. The analyses results show that the model with check valve can maintain the integrity of nuclear fuel rod effectively during reactor coolant pump rotor seizure accident.

  19. The Chernobyl accident 20 years on: an assessment of the health consequences and the international response O acidente de Chernobyl 20 anos depois: avaliação das conseqüências e resposta internacional

    Directory of Open Access Journals (Sweden)

    Keith Baverstock

    2007-06-01

    Full Text Available Twenty years after the Chernobyl accident the WHO and the International Atomic Energy Authority issued a reassuring statement about the consequences. Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment in future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. Because of the uncertainties from and the consequences of the accident, it is essential that investigations of its effects should be broadened and supported for the long term. The United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry.Vinte anos após o acidente de Chernobyl ocorrido em 1986, a OMS e a Autoridade Internacional sobre Energia Atômica lançaram um relatório sobre as conseqüências desse desastre. Nosso objetivo neste estudo é avaliar o impacto de tal acidente sobre a saúde e a reação internacional sobre o ocorrido, além de considerar se é possível melhorar as respostas em futuros desastres. Observamos que a radiação sobre a tireóide, proveniente de radioisótopos de iodo, causou milhares de casos de câncer, mas poucas mortes; as crianças expostas foram as mais suscetíveis. O

  20. Review the number of accidents in Tehran over a two-year period and prediction of the number of events based on a time-series model

    Science.gov (United States)

    Teymuri, Ghulam Heidar; Sadeghian, Marzieh; Kangavari, Mehdi; Asghari, Mehdi; Madrese, Elham; Abbasinia, Marzieh; Ahmadnezhad, Iman; Gholizadeh, Yavar

    2013-01-01

    Background: One of the significant dangers that threaten people’s lives is the increased risk of accidents. Annually, more than 1.3 million people die around the world as a result of accidents, and it has been estimated that approximately 300 deaths occur daily due to traffic accidents in the world with more than 50% of that number being people who were not even passengers in the cars. The aim of this study was to examine traffic accidents in Tehran and forecast the number of future accidents using a time-series model. Methods: The study was a cross-sectional study that was conducted in 2011. The sample population was all traffic accidents that caused death and physical injuries in Tehran in 2010 and 2011, as registered in the Tehran Emergency ward. The present study used Minitab 15 software to provide a description of accidents in Tehran for the specified time period as well as those that occurred during April 2012. Results: The results indicated that the average number of daily traffic accidents in Tehran in 2010 was 187 with a standard deviation of 83.6. In 2011, there was an average of 180 daily traffic accidents with a standard deviation of 39.5. One-way analysis of variance indicated that the average number of accidents in the city was different for different months of the year (P < 0.05). Most of the accidents occurred in March, July, August, and September. Thus, more accidents occurred in the summer than in the other seasons. The number of accidents was predicted based on an auto-regressive, moving average (ARMA) for April 2012. The number of accidents displayed a seasonal trend. The prediction of the number of accidents in the city during April of 2012 indicated that a total of 4,459 accidents would occur with mean of 149 accidents per day during these three months. Conclusion: The number of accidents in Tehran displayed a seasonal trend, and the number of accidents was different for different seasons of the year. PMID:26120405

  1. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  2. Learning from incidents and accidents

    NARCIS (Netherlands)

    Drupsteen, L.; Kampen, J. van

    2014-01-01

    There are many different definitions for what constitutes an incident or an accident, however the focus is always on unintended and often unforeseen events that cause unintended consequences. This article is focused on the process of learning from incidents and accidents. The focus is on making sure

  3. Learning from incidents and accidents

    NARCIS (Netherlands)

    Drupsteen, L.; Kampen, J. van

    2014-01-01

    There are many different definitions for what constitutes an incident or an accident, however the focus is always on unintended and often unforeseen events that cause unintended consequences. This article is focused on the process of learning from incidents and accidents. The focus is on making sure

  4. Structure of the thyroid pathology in the radiation exposed areas of Leningrad region: late consequences of Chernobyl accident after 20 years

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, A.; Uspenskaya, A.; Bychenkova, E.; Chinchuk, I.; Novokshonov, K.; Chernikov, R.; Sleptsov, I.; Bubnov, A.; Fedotov, Y.; Makarin, V.; Karelina, Y. [Endocrinology, NWRMC FHSDA, ST-Petersburg (Russian Federation)

    2012-07-01

    After the Chernobyl accident large areas of the USSR were contaminated with fallout, it has been proved that I{sup 131} caused higher incidence of papillary thyroid cancer in children and adolescents. Further observation for over 20 years showed retention of high annual prevalence of this pathology among the population. The aim of this study is to evaluate the ultimate result of the influence of I{sup 131} on the thyroid gland. The study included 454 women living in localities affected by the Chernobyl accident in April-May 1986 (case) and 909 women living in fallout-free localities (ICCIDD method). The incidence of malignant thyroid tumors among the inhabitants of the contaminated territories is higher than in the control area. This phenomenon can not be unambiguously attributed to radiation induced cancers, but requires further investigation, perhaps by the method of carrying out continuous and all-round prophylactic medical examination. High incidence of autoimmune changes can be considered to have been caused by the action of I{sup 131} and prophylactic supplement with stable iodine

  5. Sensitivity study of the wet deposition schemes in the modelling of the Fukushima accident.

    Science.gov (United States)

    Quérel, Arnaud; Quélo, Denis; Roustan, Yelva; Mathieu, Anne; Kajino, Mizuo; Sekiyama, Thomas; Adachi, Kouji; Didier, Damien; Igarashi, Yasuhito

    2016-04-01

    The Fukushima-Daiichi release of radioactivity is a relevant event to study the atmospheric dispersion modelling of radionuclides. Actually, the atmospheric deposition onto the ground may be studied through the map of measured Cs-137 established consecutively to the accident. The limits of detection were low enough to make the measurements possible as far as 250km from the nuclear power plant. This large scale deposition has been modelled with the Eulerian model ldX. However, several weeks of emissions in multiple weather conditions make it a real challenge. Besides, these measurements are accumulated deposition of Cs-137 over the whole period and do not inform of deposition mechanisms involved: in-cloud, below-cloud, dry deposition. A comprehensive sensitivity analysis is performed in order to understand wet deposition mechanisms. It has been shown in a previous study (Quérel et al, 2016) that the choice of the wet deposition scheme has a strong impact on the assessment of the deposition patterns. Nevertheless, a "best" scheme could not be highlighted as it depends on the selected criteria: the ranking differs according to the statistical indicators considered (correlation, figure of merit in space and factor 2). A possibility to explain the difficulty to discriminate between several schemes was the uncertainties in the modelling, resulting from the meteorological data for instance. Since the move of the plume is not properly modelled, the deposition processes are applied with an inaccurate activity in the air. In the framework of the SAKURA project, an MRI-IRSN collaboration, new meteorological fields at higher resolution (Sekiyama et al., 2013) were provided and allows to reconsider the previous study. An updated study including these new meteorology data is presented. In addition, a focus on several releases causing deposition in located areas during known period was done. This helps to better understand the mechanisms of deposition involved following the

  6. Bicycle accidents.

    Science.gov (United States)

    Lind, M G; Wollin, S

    1986-01-01

    Information concerning 520 bicycle accidents and their victims was obtained from medical records and the victims' replies to questionnaires. The analyzed aspects included risk of injury, completeness of accident registrations by police and in hospitals, types of injuries and influence of the cyclists' age and sex, alcohol, fatigue, hunger, haste, physical disability, purpose of cycling, wearing of protective helmet and other clothing, type and quality of road surface, site of accident (road junctions, separate cycle paths, etc.) and turning manoeuvres.

  7. Research with radiation and radioisotopes to better understand plant physiology and agricultural consequences of radioactive contamination from the Fukushima Daiichi nuclear accident.

    Science.gov (United States)

    Nakanishi, Tomoko M

    2017-01-01

    Research carried out by me and my group over the last almost four decades are summarized here. The main emphasis of my work was and continues to be on plant physiology using radiation and radioisotopes. Plants live on water and inorganic elements. In the case of water, we developed neutron imaging methods and produced (15)O-labeled water (half-life 2 min) and applied them to understand water circulation pattern in the plant. In the case of elements, we developed neutron activation analysis methods to analyze a large number of plant tissues to follow element specific distribution. Then, we developed real-time imaging system using conventional radioisotopes for the macroscopic and microscopic observation of element movement. After the accident in Fukushima Daiichi nuclear power plant, we, the academic staff of Graduate School, have been studying agricultural effects of radioactive fallout; the main results are summarized in two books published by Springer.

  8. Development and qualification of a thermal-hydraulic nodalization for modeling station blackout accident in PSB-VVER test facility

    Energy Technology Data Exchange (ETDEWEB)

    Saghafi, Mahdi [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); Ghofrani, Mohammad Bagher, E-mail: ghofrani@sharif.edu [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); D’Auria, Francesco [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, San Piero a Grado, Pisa (Italy)

    2016-07-15

    Highlights: • A thermal-hydraulic nodalization for PSB-VVER test facility has been developed. • Station blackout accident is modeled with the developed nodalization in MELCOR code. • The developed nodalization is qualified at both steady state and transient levels. • MELCOR predictions are qualitatively and quantitatively in acceptable range. • Fast Fourier Transform Base Method is used to quantify accuracy of code predictions. - Abstract: This paper deals with the development of a qualified thermal-hydraulic nodalization for modeling Station Black-Out (SBO) accident in PSB-VVER Integral Test Facility (ITF). This study has been performed in the framework of a research project, aiming to develop an appropriate accident management support tool for Bushehr nuclear power plant. In this regard, a nodalization has been developed for thermal-hydraulic modeling of the PSB-VVER ITF by MELCOR integrated code. The nodalization is qualitatively and quantitatively qualified at both steady-state and transient levels. The accuracy of the MELCOR predictions is quantified in the transient level using the Fast Fourier Transform Base Method (FFTBM). FFTBM provides an integral representation for quantification of the code accuracy in the frequency domain. It was observed that MELCOR predictions are qualitatively and quantitatively in the acceptable range. In addition, the influence of different nodalizations on MELCOR predictions was evaluated and quantified using FFTBM by developing 8 sensitivity cases with different numbers of control volumes and heat structures in the core region and steam generator U-tubes. The most appropriate case, which provided results with minimum deviations from the experimental data, was then considered as the qualified nodalization for analysis of SBO accident in the PSB-VVER ITF. This qualified nodalization can be used for modeling of VVER-1000 nuclear power plants when performing SBO accident analysis by MELCOR code.

  9. RAIM-A model for iodine behavior in containment under severe accident condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Chul; Cho, Yeong Hun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-12-15

    Following a severe accident in a nuclear power plant, iodine is a major contributor to the potential health risks for the public. Because the amount of iodine released largely depends on its volatility, iodine's behavior in containment has been extensively studied in international programs such as International Source Term Programme-Experimental Program on Iodine Chemistry under Radiation (EPICUR), Organization for Economic Co-operation and Development (OECD)-Behaviour of Iodine Project, and OECD-Source Term Evaluation and Mitigation. Korea Institute of Nuclear Safety (KINS) has joined these programs and is developing a simplified, stand-alone iodine chemistry model, RAIM (Radio-Active Iodine chemistry Model), based on the IMOD methodology and other previous studies. This model deals with chemical reactions associated with the formation and destruction of iodine species and surface reactions in the containment atmosphere and the sump in a simple manner. RAIM was applied to a simulation of four EPICUR tests and one Radioiodine Test Facility test, which were carried out in aqueous or gaseous phases. After analysis, the results show a trend of underestimation of organic and molecular iodine for the gas-phase experiments, the opposite of that for the aqueous-phase ones, whereas the total amount of volatile iodine species agrees well between the experiment and the analysis result.

  10. Bow-tie model for offshore drilling blowout accident%海上钻井井喷事故的蝴蝶结模型

    Institute of Scientific and Technical Information of China (English)

    薛鲁宁; 樊建春; 张来斌

    2013-01-01

    海上钻井是一个复杂的动态系统,同时又与一般的过程工业一样,可以划分为清晰的操作步骤和流程,因此安全屏障理论的过程模型非常适合分析海上钻井作业的安全.井喷是海上钻井作业的重要威胁,井喷事故模型对于指导海上钻井安全有重要意义.以安全屏障为基础,利用事故树和事件树分析方法,建立了海上钻井井喷事故的蝴蝶结模型.利用事故树方法分析了井喷事件的原因,通过事件树方法分析了井喷发生后火灾爆炸事故的发展过程.通过将事件原因及事故后果综合为一个模型,操作者可以很直观地了解井喷事故的发生发展过程,进而为其寻找相应的预防及控制措施提供指导.最后将“深水地平线”事故应用于该模型,验证了该模型分析海上钻井井喷事故的有效性.%Offshore drilling is a complex and dynamic system. Meanwhile, like any other process industry, it can also be divided into several independent operating steps and procedures. Therefore, the process model of safety barrier is very suitable to analyze safety of offshore drilling operations. Blowout was an important threat to offshore drilling. A blowout accident model is very meaningful to instruct offshore drilling safety. Based on safety barrier theory, a bow-tie model for offshore drilling blowout was established by utilizing fault tree and event tree methods. Causes of an offshore drilling blowout event were analyzed by fault tree, while development processes of fire & explosion accident after a blowout event were analyzed by event tree. Causes of an offshore drilling blowout event and consequences of fire & explosion accident after the blowout were combined into a single model. This model is very convenient for operators to understand the whole generating and developing process of an offshore drilling blowout accident. Therefore, it can be used as a guide for offshore drilling operators to find relevant

  11. Accidents in nuclear ships

    Energy Technology Data Exchange (ETDEWEB)

    Oelgaard, P.L. [Risoe National Lab., Roskilde (Denmark)]|[Technical Univ. of Denmark, Lyngby (Denmark)

    1996-12-01

    This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10{sup -3} per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au).

  12. Using Numerical Models in the Development of Software Tools for Risk Management of Accidents with Oil and Inert Spills

    Science.gov (United States)

    Fernandes, R.; Leitão, P. C.; Braunschweig, F.; Lourenço, F.; Galvão, P.; Neves, R.

    2012-04-01

    The increasing ship traffic and maritime transport of dangerous substances make it more difficult to significantly reduce the environmental, economic and social risks posed by potential spills, although the security rules are becoming more restrictive (ships with double hull, etc.) and the surveillance systems are becoming more developed (VTS, AIS). In fact, the problematic associated to spills is and will always be a main topic: spill events are continuously happening, most of them unknown for the general public because of their small scale impact, but with some of them (in a much smaller number) becoming authentic media phenomena in this information era, due to their large dimensions and environmental and social-economic impacts on ecosystems and local communities, and also due to some spectacular or shocking pictures generated. Hence, the adverse consequences posed by these type of accidents, increase the preoccupation of avoiding them in the future, or minimize their impacts, using not only surveillance and monitoring tools, but also increasing the capacity to predict the fate and behaviour of bodies, objects, or substances in the following hours after the accident - numerical models can have now a leading role in operational oceanography applied to safety and pollution response in the ocean because of their predictive potential. Search and rescue operation, oil, inert (ship debris, or floating containers), and HNS (hazardous and noxious substances) spills risk analysis are the main areas where models can be used. Model applications have been widely used in emergency or planning issues associated to pollution risks, and contingency and mitigation measures. Before a spill, in the planning stage, modelling simulations are used in environmental impact studies, or risk maps, using historical data, reference situations, and typical scenarios. After a spill, the use of fast and simple modelling applications allow to understand the fate and behaviour of the spilt

  13. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Heams, T J [Science Applications International Corp., Albuquerque, NM (United States); Williams, D A; Johns, N A; Mason, A [UKAEA, Winfrith, (England); Bixler, N E; Grimley, A J [Sandia National Labs., Albuquerque, NM (United States); Wheatley, C J [UKAEA, Culcheth (England); Dickson, L W [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Osborn-Lee, I [Oak Ridge National Lab., TN (United States); Domagala, P; Zawadzki, S; Rest, J [Argonne National Lab., IL (United States); Alexander, C A [Battelle, Columbus, OH (United States); Lee, R Y [Nuclear Regulatory Commission, Washington, DC (United States)

    1992-12-01

    The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided.

  14. Using meteorological ensembles for atmospheric dispersion modelling of the Fukushima nuclear accident

    Science.gov (United States)

    Périllat, Raphaël; Korsakissok, Irène; Mallet, Vivien; Mathieu, Anne; Sekiyama, Thomas; Didier, Damien; Kajino, Mizuo; Igarashi, Yasuhito; Adachi, Kouji

    2016-04-01

    Dispersion models are used in response to an accidental release of radionuclides of the atmosphere, to infer mitigation actions, and complement field measurements for the assessment of short and long term environmental and sanitary impacts. However, the predictions of these models are subject to important uncertainties, especially due to input data, such as meteorological fields or source term. This is still the case more than four years after the Fukushima disaster (Korsakissok et al., 2012, Girard et al., 2014). In the framework of the SAKURA project, an MRI-IRSN collaboration, a meteorological ensemble of 20 members designed by MRI (Sekiyama et al. 2013) was used with IRSN's atmospheric dispersion models. Another ensemble, retrieved from ECMWF and comprising 50 members, was also used for comparison. The MRI ensemble is 3-hour assimilated, with a 3-kilometers resolution, designed to reduce the meteorological uncertainty in the Fukushima case. The ECMWF is a 24-hour forecast with a coarser grid, representative of the uncertainty of the data available in a crisis context. First, it was necessary to assess the quality of the ensembles for our purpose, to ensure that their spread was representative of the uncertainty of meteorological fields. Using meteorological observations allowed characterizing the ensembles' spread, with tools such as Talagrand diagrams. Then, the uncertainty was propagated through atmospheric dispersion models. The underlying question is whether the output spread is larger than the input spread, that is, whether small uncertainties in meteorological fields can produce large differences in atmospheric dispersion results. Here again, the use of field observations was crucial, in order to characterize the spread of the ensemble of atmospheric dispersion simulations. In the case of the Fukushima accident, gamma dose rates, air activities and deposition data were available. Based on these data, selection criteria for the ensemble members were

  15. Review of experimental data for modelling LWR fuel cladding behaviour under loss of coolant accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park (Sweden)

    2007-02-15

    Extensive range of experiments has been conducted in the past to quantitatively identify and understand the behaviour of fuel rod under loss-of-coolant accident (LOCA) conditions in light water reactors (LWRs). The obtained experimental data provide the basis for the current emergency core cooling system acceptance criteria under LOCA conditions for LWRs. The results of recent experiments indicate that the cladding alloy composition and high burnup effects influence LOCA acceptance criteria margins. In this report, we review some past important and recent experimental results. We first discuss the background to acceptance criteria for LOCA, namely, clad embrittlement phenomenology, clad embrittlement criteria (limitations on maximum clad oxidation and peak clad temperature) and the experimental bases for the criteria. Two broad kinds of test have been carried out under LOCA conditions: (i) Separate effect tests to study clad oxidation, clad deformation and rupture, and zirconium alloy allotropic phase transition during LOCA. (ii) Integral LOCA tests, in which the entire LOCA sequence is simulated on a single rod or a multi-rod array in a fuel bundle, in laboratory or in a tests and results are discussed and empirical correlations deduced from these tests and quantitative models are conferred. In particular, the impact of niobium in zirconium base clad and hydrogen content of the clad on allotropic phase transformation during LOCA and also the burst stress are discussed. We review some recent LOCA integral test results with emphasis on thermal shock tests. Finally, suggestions for modelling and further evaluation of certain experimental results are made.

  16. Development of two-dimensional hot pool model and analysis of the ULOHS accident in KALIMER design

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Bum; Jeong, K. S.; Hahn, H. D

    2000-10-01

    In the new version of HP2D program, the variation model of the hot pool sodium level is added so that the temperature and velocity profiles can be predicted more accurately than old version. To verify and validate the developed new version model, comparison of the MONJU experimental data with the predicted one is performed and analyzed. And also the ULOHS(Unprotected Loss of Heat Sink) accident in the KALIMER design is performed and analyzed.

  17. The accident simulation and consequence analysis of the hydrogen refueling station leakage%加氢站氢气泄漏事故模拟及后果分析

    Institute of Scientific and Technical Information of China (English)

    杨灿剑; 付晋

    2011-01-01

    Aim at the safety of hydrogen refueling station, the theoretical model analysis and numerical simulation was carried out to simulate the accident and consequence. The concentration contours were obtained by the in house MATLAB gauss diffusion code. The influence on hydrogen diffusion of wind speed in the surroundings was analyzed. That is, the hazardous area decreased when the wind speed up. The CFD code Fluent was adopted to build a 2D full-scale hydrogen leakage in the hydrogen refueling station. The results showed that, under calm condition, the horizontal and vertical hydrogen diffusions are very fast and tend to accumulate forming explosive gas cloud. But under 10 m/s wind, the escaping gas is driven, blown away and diluted and it is hard to gather. The blast area is limited next to the leaking source. The wind is not benefit to the hydrogen diffusion but is good for safety.%针对加氢站安全,通过理论模型分析和数值模拟两种方法,对其开展事故模拟和后果分析.利用自行编制的MATLAB高斯扩散程序得到爆炸危险区域的浓度曲线,分析环境风速对氢气扩散的影响,即风速越大,危险区域越向泄漏口收缩;利用CFD软件Fluent建立加氢站氢气泄漏全场景二维模型,模拟结果表明,无风情况下,氢气水平和垂直扩散速度很快,容易富集并形成爆炸气团,而在风速10 m/s情况下,泄漏氮气被带动、吹散和稀释,难以富集,爆炸区域仅限于泄漏点附近.环境风不利于氢气稳定扩散,对安全有利.

  18. Development of comprehensive accident models for two-lane rural highways using exposure, geometry, consistency and context variables.

    Science.gov (United States)

    Cafiso, Salvatore; Di Graziano, Alessandro; Di Silvestro, Giacomo; La Cava, Grazia; Persaud, Bhagwant

    2010-07-01

    In Europe, approximately 60% of road accident fatalities occur on two-lane rural roads. Thus, research to develop and enhance explanatory and predictive models for this road type continues to be of interest in mitigating these accidents. To this end, this paper describes a novel and extensive data collection and modeling effort to define accident models for two-lane road sections based on a unique combination of exposure, geometry, consistency and context variables directly related to the safety performance. The first part of the paper documents how these were identified for the segmentation of highways into homogeneous sections. Next, is a description of the extensive data collection effort that utilized differential cinematic GPS surveys to define the horizontal alignment variables, and road safety inspections (RSIs) to quantify the other road characteristics related to safety. The final part of the paper focuses on the calibration of models for estimating the expected number of accidents on homogeneous sections that can be characterized by constant values of the explanatory variables. Several candidate models were considered for calibration using the Generalized Linear Modeling (GLM) approach. After considering the statistical significance of the parameters related to exposure, geometry, consistency and context factors, and goodness of fit statistics, 19 models were ranked and three were selected as the recommended models. The first of the three is a base model, with length and traffic as the only predictor variables; since these variables are the only ones likely to be available network-wide, this base model can be used in an empirical Bayesian calculation to conduct network screening for ranking "sites with promise" of safety improvement. The other two models represent the best statistical fits with different combinations of significant variables related to exposure, geometry, consistency and context factors. These multiple variable models can be used, with

  19. Modeling and sensitivity analysis of transport and deposition of radionuclides from the Fukushima Daiichi accident

    Directory of Open Access Journals (Sweden)

    X. Hu

    2014-01-01

    Full Text Available The atmospheric transport and ground deposition of radioactive isotopes 131I and 137Cs during and after the Fukushima Daiichi Nuclear Power Plant (FDNPP accident (March 2011 are investigated using the Weather Research and Forecasting/Chemistry (WRF/Chem model. The aim is to assess the skill of WRF in simulating these processes and the sensitivity of the model's performance to various parameterizations of unresolved physics. The WRF/Chem model is first upgraded by implementing a radioactive decay term into the advection-diffusion solver and adding three parameterizations for dry deposition and two parameterizations for wet deposition. Different microphysics and horizontal turbulent diffusion schemes are then tested for their ability to reproduce observed meteorological conditions. Subsequently, the influence on the simulated transport and deposition of the characteristics of the emission source, including the emission rate, the gas partitioning of 131I and the size distribution of 137Cs, is examined. The results show that the model can predict the wind fields and rainfall realistically. The ground deposition of the radionuclides can also potentially be captured well but it is very sensitive to the emission characterization. It is found that the total deposition is most influenced by the emission rate for both 131I and 137Cs; while it is less sensitive to the dry deposition parameterizations. Moreover, for 131I, the deposition is also sensitive to the microphysics schemes, the horizontal diffusion schemes, gas partitioning and wet deposition parameterizations; while for 137Cs, the deposition is very sensitive to the microphysics schemes and wet deposition parameterizations, and it is also sensitive to the horizontal diffusion schemes and the size distribution.

  20. HCTISN - Plenary extraordinary meeting on the 9 March 2012 - General consequences of the earthquake and tsunami; Status of Fukushima-Dai-ichi nuclear installations; The Fukushima accident, one year after: environmental and health situation in Japan; Protective actions undertaken by Japanese authorities; Support by AREVA to Japan after the Fukushima accident; What went on in Fukushima? Implementation of the IAEA nuclear safety action plan; Review of European stress tests by the peers; Opinion of the ASN on complementary safety assessments (CSAs); HCTISN - Reunion pleniere extraordinaire du 9 mars 2012: Consequences generales du seisme et du tusnami; Situation des installations nucleaires de Fukushima Dai-ichi; L'accident de Fukushima 1 an apres: situation environnementale et sanitaire au Japon; Les actions de protection engagees par les autorites japonaises; Aide apportee par AREVA au Japon suite a l'accident de Fukushima; Que s'est-il passe a Fukushima?

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, Susumu [Ambassade du Japon en France, 7 Avenue Hoche, 75008 Paris (France); Charles, T.; Champion, Didier [Institut de radioprotection et de surete nucleaire - IRSN, 31, avenue de la Division Leclerc, 92260 Fontenay-aux-Roses (France); Jean-Luc Godet [Autorite de surete nucleaire, 6, place du Colonel Bourgoin, 75012 Paris (France); ASN/DIS, 10, Route du Panorama, 92266 Fontenay-aux-Roses cedex (France); Arnaud GAY [Business Unit Valorisation - AREVA (France); Philippe Jamet [European Nuclear Safety Regulators Group - ENSREG, Autorite de surete nucleaire, 6, place du Colonel Bourgoin, 75012 Paris (France)

    2012-03-09

    This document contains Power Point presentations proposed during a plenary session of the High Committee transparency and information on nuclear safety (HCTISN). The contributions addressed the Fukushima accident (the earthquake and the tsunami, the technical consequences on the plant, the consequences on the environment and on health, the different actions undertaken in Japan to protect the population, the consequences on nuclear safety in other countries with notably the performance of stress tests or the organisation of complementary safety assessments on the French fleet of nuclear reactors

  1. Inverse estimation of source parameters of oceanic radioactivity dispersion models associated with the Fukushima accident

    Directory of Open Access Journals (Sweden)

    Y. Miyazawa

    2013-04-01

    Full Text Available With combined use of the ocean–atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant (FNPP that occurred in March 2011. The Green's function approach is adopted for the estimation of two parameters determining the total emission amounts for the period from 12 March to 6 May 2011. It is confirmed that the validity of the estimation depends on the simulation skill near FNPP. The total amount of the direct release is estimated as 5.5–5.9 × 1015 Bq, while that of the atmospheric deposition is estimated as 5.5–9.7 × 1015 Bq, which indicates broader range of the estimate than that of the direct release owing to uncertainty of the dispersion widely spread over the western North Pacific.

  2. Inverse estimation of source parameters of oceanic radioactivity dispersion models associated with the Fukushima accident

    Directory of Open Access Journals (Sweden)

    Y. Miyazawa

    2012-10-01

    Full Text Available With combined use of the ocean-atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the Western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant (FNPP that occurred in March 2011. The Green's function approach is adopted for the estimation of two parameters determining the total emission amounts for the period from 12 March to 6 May 2011. It is confirmed that the validity of the estimation depends on the simulation skill near FNPP. The total amount of the direct release is estimated as 5.5–5.9 × 1015 Bq, while that of the atmospheric deposition is estimated as 5.5–9.7 × 1015 Bq, which indicates broader range of the estimate than that of the direct release owing to uncertainty of the dispersion widely spread over the Western North Pacific.

  3. Persistence of airline accidents.

    Science.gov (United States)

    Barros, Carlos Pestana; Faria, Joao Ricardo; Gil-Alana, Luis Alberiko

    2010-10-01

    This paper expands on air travel accident research by examining the relationship between air travel accidents and airline traffic or volume in the period from 1927-2006. The theoretical model is based on a representative airline company that aims to maximise its profits, and it utilises a fractional integration approach in order to determine whether there is a persistent pattern over time with respect to air accidents and air traffic. Furthermore, the paper analyses how airline accidents are related to traffic using a fractional cointegration approach. It finds that airline accidents are persistent and that a (non-stationary) fractional cointegration relationship exists between total airline accidents and airline passengers, airline miles and airline revenues, with shocks that affect the long-run equilibrium disappearing in the very long term. Moreover, this relation is negative, which might be due to the fact that air travel is becoming safer and there is greater competition in the airline industry. Policy implications are derived for countering accident events, based on competition and regulation. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.

  4. Modeling the early-phase redistribution of radiocesium fallouts in an evergreen coniferous forest after Chernobyl and Fukushima accidents

    Energy Technology Data Exchange (ETDEWEB)

    Calmon, P.; Gonze, M.-A.; Mourlon, Ch.

    2015-10-01

    Following the Chernobyl accident, the scientific community gained numerous data on the transfer of radiocesium in European forest ecosystems, including information regarding the short-term redistribution of atmospheric fallout onto forest canopies. In the course of international programs, the French Institute for Radiological Protection and Nuclear Safety (IRSN) developed a forest model, named TREE4 (Transfer of Radionuclides and External Exposure in FORest systems), 15 years ago. Recently published papers on a Japanese evergreen coniferous forest contaminated by Fukushima radiocesium fallout provide interesting and quantitative data on radioactive mass fluxes measured within the forest in the months following the accident. The present study determined whether the approach adopted in the TREE4 model provides satisfactory results for Japanese forests or whether it requires adjustments. This study focused on the interception of airborne radiocesium by forest canopy, and the subsequent transfer to the forest floor through processes such as litterfall, throughfall, and stemflow, in the months following the accident. We demonstrated that TREE4 quite satisfactorily predicted the interception fraction (20%) and the canopy-to-soil transfer (70% of the total deposit in 5 months) in the Tochigi forest. This dynamics was similar to that observed in the Höglwald spruce forest. However, the unexpectedly high contribution of litterfall (31% in 5 months) in the Tochigi forest could not be reproduced in our simulations (2.5%). Possible reasons for this discrepancy are discussed; and sensitivity of the results to uncertainty in deposition conditions was analyzed. - Highlights: • Transfer of radiocesium atmospheric fallout in evergreen forests was modeled. • The model was tested using observations from Chernobyl and Fukushima accidents. • Model predictions of canopy interception and depuration agree with measurements. • Unexpectedly high contribution of litterfall for the

  5. Dermatological consequences of the Cs-137 radiological accident in Goiania, Goias State, Brazil; Repercussoes dermatologicas no acidente radioativo com o Cesio 137 em Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Lia Candida Miranda de

    1996-07-01

    The objective of the present study was to analyse the occurrence of dermatosis in individuals that had been exposed to cesium{sup 137} during the radioactive accident in Goiania, in 1987 and detect pre-cancerous dermatosis or those predictive of low immunity. The groups were evaluated according to the intensity of radiation they had been exposed to and then compared to a control group of people not exposed to radiation. The population exposed to the cesium{sup 137} was comprised of 109 people, who were divided into Groups I and II, according to the CNEN norms. In group I, 54 people with {<=} 20 rads exposure and/or radio lesion were included; in group II, 55 people with > 20 rads exposure were included, along with the children of group I individuals. This was a historic cohort study, that is, a retrospective study that lasted 9 years, extending from September of 1987 to August, 1996. The presence of the oncoprotein p-53 was studied in the radio lesions of 10 patients. There is no evidence of an increase in the incidence of dermatosis in the exposed groups, excepts for pyoderma in patients with radio lesions. The most frequent dermatosis were: pyoderma, pityriasis versicolor, scabies, dermatophytosis and seborrhoeic dermatitis. The results obtained were not statistically significant for the evaluation of dermatosis predictive of low immunity or precancerous lesions. The oncoprotein p-53 in individuals with radio lesion showed a 80% positivity rate and risk factor estimated in 8 times, for the test. It has proved to be useful because it represents one more option in terms of propaedeutic evaluation and suggests that one should pay close and continuous attention in order to better control the evolution of these individuals. (author)

  6. Risk assessment and consequence modeling of BLEVE explosion wave phenomenon of LPG spherical tank in a refinery

    Directory of Open Access Journals (Sweden)

    Mohammad Kamaei

    2016-06-01

    Full Text Available Introduction: Although human industrial activities are as a part of efforts to achieve greater prosperity, the risks related to these activities are also expanding. Hazard identification and risk assessment in the oil and gas industries are essential to reduce the frequency and severity of accidents and minimize damage to people and property before their occurrence. The aim of this study was to evaluate the liquefied and pressurized petroleum gas spherical tanks in a refinery and assessing the risks of Boiling Liquid Expanding Vapor Explosion (BLEVE phenomenon. Material and Method: In this study, the risks of BLEVE phenomenon were assessed, using the Bowtie method. The consequences of explosion wave phenomenon and the resulting wave quantity and its impacts on the neighboring machineries and equipment were analyzed. PHAST software version 6.54 has been used for modeling the BLEVE phenomenon. Result: In this evaluation, generally five causes and two consequences were identified for BLEVE phenomenon. In order to reduce its consequences, forty-three controlling measures were introduced to prevent the BLEVE phenomenon and the impacts of 31 control measures were identified. According to the conducted analysis, it was found that the spherical tank blast wave caused by LPG can lead to explosion of close located tanks which can create a chain of explosions. Conclusion: The results of modeling and risk assessment can be used to identify the BLEVE phenomenon causes and its effects on nearby people and equipment. Based on these results, preventive controlling measures can be implemented and also be determined by adopting proper design and layout, margin of safety for personnel, equipment and accessories.

  7. Assessment of accident risks in the CRBRP. Volume 2. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-03-01

    Appendices to Volume I include core-related accident-sequence definition, CRBRP risk-assessment sequence-probability determinations, failure-probability data, accident scenario evaluation, radioactive material release analysis, ex-core accident analysis, safety philosophy and design features, calculation of reactor accident consequences, sensitivity study, and risk from fires.

  8. The Fukushima accident; Accident nucleaire a Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Delbecq, D.

    2012-02-15

    The Fukushima accident is characterized by a sequence of natural disasters: earthquake and tsunamis that deprived simultaneously 3 reactors from cooling and electrical power for quite a long time. A series of hydrogen explosion has added to the mess. Experts agree to say that certainly nuclear fuel has melt to form corium in all 3 reactors. The accident has contaminated tens of thousand acres of land around the plant and has jeopardized local coastal fishery. The human toll is unexpectedly low: no direct casualty in the population but several suicides among the people that was forced to leave their home. 5 people from the plant staff died certainly from the consequences of the tsunami. (A.C.)

  9. Inclusion of models to describe severe accident conditions in the fuel simulation code DIONISIO

    Energy Technology Data Exchange (ETDEWEB)

    Lemes, Martín; Soba, Alejandro [Sección Códigos y Modelos, Gerencia Ciclo del Combustible Nuclear, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina); Daverio, Hernando [Gerencia Reactores y Centrales Nucleares, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina); Denis, Alicia [Sección Códigos y Modelos, Gerencia Ciclo del Combustible Nuclear, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina)

    2017-04-15

    The simulation of fuel rod behavior is a complex task that demands not only accurate models to describe the numerous phenomena occurring in the pellet, cladding and internal rod atmosphere but also an adequate interconnection between them. In the last years several models have been incorporated to the DIONISIO code with the purpose of increasing its precision and reliability. After the regrettable events at Fukushima, the need for codes capable of simulating nuclear fuels under accident conditions has come forth. Heat removal occurs in a quite different way than during normal operation and this fact determines a completely new set of conditions for the fuel materials. A detailed description of the different regimes the coolant may exhibit in such a wide variety of scenarios requires a thermal-hydraulic formulation not suitable to be included in a fuel performance code. Moreover, there exist a number of reliable and famous codes that perform this task. Nevertheless, and keeping in mind the purpose of building a code focused on the fuel behavior, a subroutine was developed for the DIONISIO code that performs a simplified analysis of the coolant in a PWR, restricted to the more representative situations and provides to the fuel simulation the boundary conditions necessary to reproduce accidental situations. In the present work this subroutine is described and the results of different comparisons with experimental data and with thermal-hydraulic codes are offered. It is verified that, in spite of its comparative simplicity, the predictions of this module of DIONISIO do not differ significantly from those of the specific, complex codes.

  10. Accident Statistics

    Data.gov (United States)

    Department of Homeland Security — Accident statistics available on the Coast Guard’s website by state, year, and one variable to obtain tables and/or graphs. Data from reports has been loaded for...

  11. Models and numerical methods for the simulation of loss-of-coolant accidents in nuclear reactors

    Science.gov (United States)

    Seguin, Nicolas

    2014-05-01

    In view of the simulation of the water flows in pressurized water reactors (PWR), many models are available in the literature and their complexity deeply depends on the required accuracy, see for instance [1]. The loss-of-coolant accident (LOCA) may appear when a pipe is broken through. The coolant is composed by light water in its liquid form at very high temperature and pressure (around 300 °C and 155 bar), it then flashes and becomes instantaneously vapor in case of LOCA. A front of liquid/vapor phase transition appears in the pipes and may propagate towards the critical parts of the PWR. It is crucial to propose accurate models for the whole phenomenon, but also sufficiently robust to obtain relevant numerical results. Due to the application we have in mind, a complete description of the two-phase flow (with all the bubbles, droplets, interfaces…) is out of reach and irrelevant. We investigate averaged models, based on the use of void fractions for each phase, which represent the probability of presence of a phase at a given position and at a given time. The most accurate averaged model, based on the so-called Baer-Nunziato model, describes separately each phase by its own density, velocity and pressure. The two phases are coupled by non-conservative terms due to gradients of the void fractions and by source terms for mechanical relaxation, drag force and mass transfer. With appropriate closure laws, it has been proved [2] that this model complies with all the expected physical requirements: positivity of densities and temperatures, maximum principle for the void fraction, conservation of the mixture quantities, decrease of the global entropy… On the basis of this model, it is possible to derive simpler models, which can be used where the flow is still, see [3]. From the numerical point of view, we develop new Finite Volume schemes in [4], which also satisfy the requirements mentioned above. Since they are based on a partial linearization of the physical

  12. Determinants of participation in a longitudinal two-stage study of the health consequences of the Chornobyl nuclear power plant accident

    Directory of Open Access Journals (Sweden)

    Zakhozha Victoria

    2008-05-01

    Full Text Available Abstract Background The determinants of participation in long-term follow-up studies of disasters have rarely been delineated. Even less is known from studies of events that occurred in eastern Europe. We examined the factors associated with participation in a longitudinal two-stage study conducted in Kyiv following the 1986 Chornobyl nuclear power plant accident. Methods Six hundred child-mother dyads (300 evacuees and 300 classmate controls were initially assessed in 1997 when the children were 11 years old, and followed up in 2005–6 when they were 19 years old. A population control group (304 mothers and 327 children was added in 2005–6. Each assessment point involved home interviews with the children and mothers (stage 1, followed by medical examinations of the children at a clinic (stage 2. Background characteristics, health status, and Chornobyl risk perceptions were examined. Results The participation rates in the follow-up home interviews were 87.8% for the children (88.6% for evacuees; 87.0% for classmates and 83.7% for their mothers (86.4% for evacuees and 81.0% for classmates. Children's and mothers' participation was predicted by one another's study participation and attendance at the medical examination at time 1. Mother's participation was also predicted by initial concerns about her child's health, greater psychological distress, and Chornobyl risk perceptions. In 1997, 91.2% of the children had a medical examination (91.7% of evacuees and 90.7% of classmates; in 2005–6, 85.2% were examined (83.0% of evacuees, 87.7% of classmates, 85.0% of population controls. At both times, poor health perceptions were associated with receiving a medical examination. In 2005–6, clinic attendance was also associated with the young adults' risk perceptions, depression or generalized anxiety disorder, lower standard of living, and female gender. Conclusion Despite our low attrition rates, we identified several determinants of selective

  13. Sports Accidents

    CERN Multimedia

    Kiebel

    1972-01-01

    Le Docteur Kiebel, chirurgien à Genève, est aussi un grand ami de sport et de temps en temps médecin des classes genevoises de ski et également médecin de l'équipe de hockey sur glace de Genève Servette. Il est bien qualifié pour nous parler d'accidents de sport et surtout d'accidents de ski.

  14. Consequences of spatial autocorrelation for niche-based models

    DEFF Research Database (Denmark)

    Segurado, P.; Araújo, Miguel B.; Kunin, W. E.

    2006-01-01

    variables, as measured by Moran's I, was analysed and compared between models. The effects of systematic subsampling of the data set and the inclusion of a contagion term to deal with spatial autocorrelation in models were assessed with projections made with GLM, as it was with this method that estimates...... were vulnerable to the effects of spatial autocorrelation. 5.  The procedures utilized to reduce the effects of spatial autocorrelation had varying degrees of success. Subsampling was partially effective in avoiding the inflation effect, whereas the inclusion of a contagion term fully eliminated......1.  Spatial autocorrelation is an important source of bias in most spatial analyses. We explored the bias introduced by spatial autocorrelation on the explanatory and predictive power of species' distribution models, and make recommendations for dealing with the problem. 2.  Analyses were based...

  15. Consequences of nonconformist behaviors in a continuous opinion model

    CERN Document Server

    Vieira, Allan R; Crokidakis, Nuno

    2016-01-01

    We investigate opinion formation in a kinetic exchange opinion model, where opinions are represented by numbers in the real interval $[-1,1]$ and agents are typified by the individual degree of conviction about the opinion that they support. Opinions evolve through pairwise interactions governed by competitive positive and negative couplings, that promote imitation and dissent, respectively. The model contemplates also another type of nonconformity such that agents can occasionally choose their opinions independently of the interactions with other agents. The steady states of the model as a function of the parameters that describe conviction, dissent and independence are analyzed, with particular emphasis on the emergence of extreme opinions. Then, we characterize the possible ordered and disordered phases and the occurrence or suppression of phase transitions that arise spontaneously due to the disorder introduced by the heterogeneity of the agents and/or their interactions.

  16. Risk factors associated with bus accident severity in the United States: A generalized ordered logit model

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    Introduction: Recent years have witnessed a growing interest in improving bus safety operations worldwide. While in the United States buses are considered relatively safe, the number of bus accidents is far from being negligible, triggering the introduction of the Motor-coach Enhanced Safety Act...... that accident severity increases: (i) for young bus drivers under the age of 25; (ii) for drivers beyond the age of 55, and most prominently for drivers over 65 years old; (iii) for female drivers; (iv) for very high (over 65 mph) and very low (under 20 mph) speed limits; (v) at intersections; (vi) because...

  17. A new interacting two-fluid model and its consequences

    Science.gov (United States)

    Sharov, G. S.; Bhattacharya, S.; Pan, S.; Nunes, R. C.; Chakraborty, S.

    2017-04-01

    In the background of a homogeneous and isotropic space-time with zero spatial curvature, we consider interacting scenarios between two barotropic fluids, one is the pressureless dark matter and the other one is dark energy (DE), in which the equation of state (EoS) in DE is either constant or time-dependent. In particular, for constant EoS in DE, we show that the evolution equations for both fluids can be analytically solved. For all these scenarios, the model parameters have been constrained using the current astronomical observations from Type Ia supernovae, Hubble parameter measurements and baryon acoustic oscillation distance measurements. Our analysis shows that both for constant and variable EoS in DE, a very small but non-zero interaction in the dark sector is favoured while the EoS in DE can predict a slight phantom nature, i.e. the EoS in DE can cross the phantom divide line '-1'. On the other hand, although the models with variable EoS describe the observations better, the Akaike Information Criterion supports models with minimal number of parameters. However, it is found that all the models are very close to the Λ cold dark matter cosmology.

  18. A two-stage optimization model for emergency material reserve layout planning under uncertainty in response to environmental accidents.

    Science.gov (United States)

    Liu, Jie; Guo, Liang; Jiang, Jiping; Jiang, Dexun; Liu, Rentao; Wang, Peng

    2016-06-05

    In the emergency management relevant to pollution accidents, efficiency emergency rescues can be deeply influenced by a reasonable assignment of the available emergency materials to the related risk sources. In this study, a two-stage optimization framework is developed for emergency material reserve layout planning under uncertainty to identify material warehouse locations and emergency material reserve schemes in pre-accident phase coping with potential environmental accidents. This framework is based on an integration of Hierarchical clustering analysis - improved center of gravity (HCA-ICG) model and material warehouse location - emergency material allocation (MWL-EMA) model. First, decision alternatives are generated using HCA-ICG to identify newly-built emergency material warehouses for risk sources which cannot be satisfied by existing ones with a time-effective manner. Second, emergency material reserve planning is obtained using MWL-EMA to make emergency materials be prepared in advance with a cost-effective manner. The optimization framework is then applied to emergency management system planning in Jiangsu province, China. The results demonstrate that the developed framework not only could facilitate material warehouse selection but also effectively provide emergency material for emergency operations in a quick response.

  19. Gender consequences of a national performance-based funding model

    DEFF Research Database (Denmark)

    Nielsen, Mathias Wullum

    2015-01-01

    This article investigates the extent to which the Danish Bibliometric Research Indicator (BRI) reflects the performance of men and women differently. The model is based on a differentiated counting of peer-reviewed publications, awarding three and eight points for contributions to ‘well-regarded’...... privileges collaborative research, which disadvantages women due to gender differences in collaborative network relations.......This article investigates the extent to which the Danish Bibliometric Research Indicator (BRI) reflects the performance of men and women differently. The model is based on a differentiated counting of peer-reviewed publications, awarding three and eight points for contributions to ‘well......-regarded’ and highly selective journals and book publishers, and 1 and 5 points for equivalent scientific contributions via ‘normal level’ channels. On the basis of bibliometric data, the study shows that the BRI considerably widens the existing gender gap in researcher performance, since men on average receive more...

  20. Consequence of reputation in the Sznajd consensus model

    Energy Technology Data Exchange (ETDEWEB)

    Crokidakis, Nuno, E-mail: nuno@if.uff.b [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, 24210-340 Niteroi, RJ (Brazil); Departamento de Fisica, I3N - Universidade de Aveiro, 3810-193 Aveiro (Portugal); Forgerini, Fabricio L., E-mail: fabricio_forgerini@ufam.edu.b [Departamento de Fisica, I3N - Universidade de Aveiro, 3810-193 Aveiro (Portugal); ISB - Universidade Federal do Amazonas, 69460-000 Coari, AM (Brazil)

    2010-07-26

    In this work we study a modified version of the Sznajd sociophysics model. In particular we introduce reputation, a mechanism that limits the capacity of persuasion of the agents. The reputation is introduced as a score which is time-dependent, and its introduction avoid dictatorship (all spins parallel) for a wide range of parameters. The relaxation time follows a log-normal-like distribution. In addition, we show that the usual phase transition also occurs, as in the standard model, and it depends on the initial concentration of individuals following an opinion, occurring at a initial density of up spins greater than 1/2. The transition point is determined by means of a finite-size scaling analysis.

  1. Industrial accidents triggered by lightning.

    Science.gov (United States)

    Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

    2010-12-15

    Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents.

  2. Risk Estimation Methodology for Launch Accidents.

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Daniel James; Lipinski, Ronald J.; Bechtel, Ryan D.

    2014-02-01

    As compact and light weight power sources with reliable, long lives, Radioisotope Power Systems (RPSs) have made space missions to explore the solar system possible. Due to the hazardous material that can be released during a launch accident, the potential health risk of an accident must be quantified, so that appropriate launch approval decisions can be made. One part of the risk estimation involves modeling the response of the RPS to potential accident environments. Due to the complexity of modeling the full RPS response deterministically on dynamic variables, the evaluation is performed in a stochastic manner with a Monte Carlo simulation. The potential consequences can be determined by modeling the transport of the hazardous material in the environment and in human biological pathways. The consequence analysis results are summed and weighted by appropriate likelihood values to give a collection of probabilistic results for the estimation of the potential health risk. This information is used to guide RPS designs, spacecraft designs, mission architecture, or launch procedures to potentially reduce the risk, as well as to inform decision makers of the potential health risks resulting from the use of RPSs for space missions.

  3. Reactor physics modelling of accident tolerant fuel for LWRs using ANSWERS codes

    Directory of Open Access Journals (Sweden)

    Lindley Benjamin A.

    2016-01-01

    adopts an integral configuration and a fully passive decay heat removal system to provide indefinite cooling capability for a class of accidents. This paper presents the equilibrium cycle core design and reactor physics behaviour of the I2S-LWR with U3Si2 and the advanced steel cladding. The results were obtained using the traditional two-stage approach, in which homogenized macroscopic cross-section sets were generated by WIMS and applied in a full 3D core solution with PANTHER. The results obtained with WIMS/PANTHER were compared against the Monte Carlo Serpent code developed by VTT and previously reported results for the I2S-LWR. The results were found to be in a good agreement (e.g. <200 pcm in reactivity among the compared codes, giving confidence that the WIMS/PANTHER reactor physics package can be reliably used in modelling advanced LWR systems.

  4. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale FeCrAl Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, K. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, J. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andersson, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Capolungo, L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wirth, B. D. [Univ. of Tennessee, Knoxville, TN (United States)

    2017-07-26

    Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced ac- cident tolerance when compared to traditional UO2 fuel zircaloy clad fuel rods. One of the potential replacement claddings are iron-chromium-alunimum (FeCrAl) alloys due to their increased oxidation resistance [1–4] and higher strength [1, 2]. While the oxidation characteristics of FeCrAl are a benefit for accident tolerance, the thermal neu- tron absorption cross section of FeCrAl is about ten times that of Zircaloy. This neutronic penalty necessitates thinner cladding. This allows for slightly larger pellets to give the same cold gap width in the rod. However, the slight increase in pellet diameter is not sufficient to compensate for the neutronic penalty and enriching the fuel beyond the current 5% limit appears to be necessary [5]. Current estimates indicate that this neutronic penalty will impose an increase in fuel cost of 15-35% [1, 2]. In addition to the neutronic disadvantage, it is anticipated that tritium release to the coolant will be larger because the permeability of hydrogen in FeCrAl is about 100 times higher than in Zircaloy [6]. Also, radiation-induced hardening and embrittlement of FeCrAl need to be fully characterized experimentally [7]. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022 [8] multiscale multiphysics modeling approaches have been used to provide insight into these the use of FeCrAl as a cladding material. The purpose of this letter report is to highlight the multiscale modeling effort for iron-chromium-alunimum (FeCrAl) cladding alloys as part of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program through its Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The approach taken throughout the HIP is to

  5. Niche variability and its consequences for species distribution modeling.

    Directory of Open Access Journals (Sweden)

    Matt J Michel

    Full Text Available When species distribution models (SDMs are used to predict how a species will respond to environmental change, an important assumption is that the environmental niche of the species is conserved over evolutionary time-scales. Empirical studies conducted at ecological time-scales, however, demonstrate that the niche of some species can vary in response to environmental change. We use habitat and locality data of five species of stream fishes collected across seasons to examine the effects of niche variability on the accuracy of projections from Maxent, a popular SDM. We then compare these predictions to those from an alternate method of creating SDM projections in which a transformation of the environmental data to similar scales is applied. The niche of each species varied to some degree in response to seasonal variation in environmental variables, with most species shifting habitat use in response to changes in canopy cover or flow rate. SDMs constructed from the original environmental data accurately predicted the occurrences of one species across all seasons and a subset of seasons for two other species. A similar result was found for SDMs constructed from the transformed environmental data. However, the transformed SDMs produced better models in ten of the 14 total SDMs, as judged by ratios of mean probability values at known presences to mean probability values at all other locations. Niche variability should be an important consideration when using SDMs to predict future distributions of species because of its prevalence among natural populations. The framework we present here may potentially improve these predictions by accounting for such variability.

  6. ITER transient consequences for material damage: modelling versus experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bazylev, B [Forschungszentrum Karlsruhe, IHM, P O Box 3640, 76021 Karlsruhe (Germany); Janeschitz, G [Forschungszentrum Karlsruhe, Fusion, P O Box 3640, 76021 Karlsruhe (Germany); Landman, I [Forschungszentrum Karlsruhe, IHM, P O Box 3640, 76021 Karlsruhe (Germany); Pestchanyi, S [Forschungszentrum Karlsruhe, IHM, P O Box 3640, 76021 Karlsruhe (Germany); Loarte, A [EFDA Close Support Unit Garching, Boltmannstr 2, D-85748 Garching (Germany); Federici, G [ITER International Team, Garching Working Site, Boltmannstr 2, D-85748 Garching (Germany); Merola, M [ITER International Team, Garching Working Site, Boltmannstr 2, D-85748 Garching (Germany); Linke, J [Forschungszentrum Juelich, EURATOM-Association, D-52425 Juelich (Germany); Zhitlukhin, A [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Podkovyrov, V [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Klimov, N [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation); Safronov, V [SRC RF TRINITI, Troitsk, 142190, Moscow Region (Russian Federation)

    2007-03-15

    Carbon-fibre composite (CFC) and tungsten macrobrush armours are foreseen as PFC for the ITER divertor. In ITER the main mechanisms of metallic armour damage remain surface melting and melt motion erosion. In the case of CFC armour, due to rather different heat conductivities of CFC fibres a noticeable erosion of the PAN bundles may occur at rather small heat loads. Experiments carried out in the plasma gun facilities QSPA-T for the ITER like edge localized mode (ELM) heat load also demonstrated significant erosion of the frontal and lateral brush edges. Numerical simulations of the CFC and tungsten (W) macrobrush target damage accounting for the heat loads at the face and lateral brush edges were carried out for QSPA-T conditions using the three-dimensional (3D) code PHEMOBRID. The modelling results of CFC damage are in a good qualitative and quantitative agreement with the experiments. Estimation of the droplet splashing caused by the Kelvin-Helmholtz (KH) instability was performed.

  7. Numerical 3D modelling of oil dispersion in the sea due to different accident scenarios

    Science.gov (United States)

    Guandalini, Roberto; Agate, Giordano; Moia, Fabio

    2017-04-01

    The purpose of the study has been the development of a methodology, based on a numerical 3D approach, for the analysis of oil dispersion in the sea, in order to simulate with a high level of accuracy the dynamic behavior of the oil plume and its displacement in the environment. As a matter of fact, the numerical simulation is the only approach currently able to analyse in detail possible accident scenarios, even with an high degree of complexity, of different type and intensity, allowing to follow their evolution both in time and space, and to evaluate the effectiveness of suggested prevention or recovery actions. The software for these calculations is therefore an essential tool in order to simulate the impact effects in the short, medium and long period, able to account for the complexity of the sea system involved in the dispersion process and its dependency on the meteorological, marine and morphological local conditions. This software, generally based on fluid dynamic 3D simulators and modellers, is therefore extremely specialized and requires expertise for an appropriate usage, but at the same time it allows detailed scenario analyses and design verifications. It takes into account different parameters as the sea current field and its turbulence, the wind acting on the sea surface, the salinity and temperature gradients, the local coastal morphology, the seabed bathymetry and the tide. The applied methodology is based on the Integrated Fluid Dynamic Simulation System HyperSuite developed by RSE. This simulation system includes the consideration of all the parameters previously listed, in the frame of a 3D Eulerian finite element fluid dynamic model, which accuracy is guaranteed by a very detailed spatial mesh and by an automatically optimized time step management. In order to assess the methodology features, an area of more than 2500 km2 and depth of 200 m located in the middle Adriatic Sea has been modelled. The information required for the simulation in

  8. Modelling of HTR Confinement Behaviour during Accidents Involving Breach of the Helium Pressure Boundary

    Directory of Open Access Journals (Sweden)

    Joan Fontanet

    2009-01-01

    Full Text Available Development of HTRs requires the performance of a thorough safety study, which includes accident analyses. Confinement building performance is a key element of the system since the behaviour of aerosol and attached fission products within the building is of an utmost relevance in terms of the potential source term to the environment. This paper explores the available simulation capabilities (ASTEC and CONTAIN codes and illustrates the performance of a postulated HTR vented confinement under prototypical accident conditions by a scoping study based on two accident sequences characterized by Helium Pressure Boundary breaches, a small and a large break. The results obtained indicate that both codes predict very similar thermal-hydraulic responses of the confinement both in magnitude and timing. As for the aerosol behaviour, both codes predict that most of the inventory coming into the confinement is eventually depleted on the walls and only about 1% of the aerosol dust is released to the environment. The crosscomparison of codes states that largest differences are in the intercompartmental flows and the in-compartment gas composition.

  9. Status report of advanced cladding modeling work to assess cladding performance under accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    B.J. Merrill; Shannon M. Bragg-Sitton

    2013-09-01

    Scoping simulations performed using a severe accident code can be applied to investigate the influence of advanced materials on beyond design basis accident progression and to identify any existing code limitations. In 2012 an effort was initiated to develop a numerical capability for understanding the potential safety advantages that might be realized during severe accident conditions by replacing Zircaloy components in light water reactors (LWRs) with silicon carbide (SiC) components. To this end, a version of the MELCOR code, under development at the Sandia National Laboratories in New Mexico (SNL/NM), was modified by replacing Zircaloy for SiC in the MELCOR reactor core oxidation and material properties routines. The modified version of MELCOR was benchmarked against available experimental data to ensure that present SiC oxidation theory in air and steam were correctly implemented in the code. Additional modifications have been implemented in the code in 2013 to improve the specificity in defining components fabricated from non-standard materials. An overview of these modifications and the status of their implementation are summarized below.

  10. Analysis on the `Thermite` reaction consequences in accidents involving research reactors using plate-type fuel; Analisis sobre las concequencias de la reaccion `Termita` en caso de accidentes en reactores de investigacion que utilizan combustible tipo placa

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Norma L.; Bruno, Hernan R.; Camacho, Esteban F.; Cincotta, Daniel O.; Yorio, Daniel [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Constituyentes

    1999-11-01

    The mixture of Al-U{sub 3} O{sub 8} is not in a state of chemical equilibrium, and at temperatures of between 850 deg C and 1000 deg C, it reacts exo thermally. This is known, in corresponding bibliography as a `Thermite reaction. This mixture is used in the manufacturing of the plate-type fuel used in research reactors. It has been pointed out that the release of energy caused by this type of reactions might represent a risk in case of accidents in this type of reactor. Conclusions, in general, tend to indicate that no such risk exists, although no concrete assurance is given that this is the case, and this fact, therefore, leaves room for doubt. The objective of this paper is to provide an in-depth study of what happens to a fuel plate when it is subjected to thermite reaction. We will, furthermore, analyze the consequences of the release of energy generated by this type of reaction within the core of the reactor, clearly defining the problem for this type of fuel and this kind of reactor. (author) 3 refs., 9 figs., 1 tab.

  11. Radiological assessment by compartment model POSEIDON-R of radioactivity released in the ocean following Fukushima Daiichi accident

    Science.gov (United States)

    Bezhenar, Roman; Maderich, Vladimir; Heling, Rudie; Jung, Kyung Tae; Myoung, Jung-Goo

    2013-04-01

    The modified compartment model POSEIDON-R (Lepicard et al, 2004), was applied to the North-Western Pacific and adjacent seas. It is for the first time, that a compartment model was used in this region, where 25 Nuclear Power Plants (NPP) are operated. The aim of this study is to perform a radiological assessment of the releases of radioactivity due to the Fukushima Daiichi accident. The model predicts the dispersion of radioactivity in water column and in the sediments, and the transfer of radionuclides throughout the marine food web, and the subsequent doses to the population due to the consumption of fishery products. A generic predictive dynamical food-chain model is used instead of concentration factor (CF) approach. The radionuclide uptake model for fish has as central feature the accumulation of radionuclides in the target tissue. Three layer structure of the water column makes it possible to describe deep-water transport adequately. In total 175 boxes cover the Northwestern Pacific, the East China Sea, and the Yellow Sea and East/Japan Sea. Water fluxes between boxes were calculated by averaging three-dimensional currents obtained by hydrodynamic model ROMS over a 10-years period. Tidal mixing between boxes was parameterized. The model was validated on observation data on the Cs-137 in water for the period 1945-2004. The source terms from nuclear weapon tests are regional source term from the bomb tests on Atoll Enewetak and Atoll Bikini and global deposition from weapons tests. The correlation coefficient between predicted and observed concentrations of Cs-137 in the surface water is 0.925 and RMSE=1.43 Bq/m3. A local-scale coastal box was used according POSEIDON's methodology to describe local processes of activity transport, deposition and food web around the Fukushima Daiichi NPP. The source term to the ocean from the Fukushima accident includes a 10-days release of Cs-134 (5 PBq) and Cs-137 (4 PBq) directly into the ocean and 6 and 5 PBq of Cs-134 and

  12. Analysis of multiple tank car releases in train accidents.

    Science.gov (United States)

    Liu, Xiang; Liu, Chang; Hong, Yili

    2017-10-01

    There are annually over two million carloads of hazardous materials transported by rail in the United States. The American railroads use large blocks of tank cars to transport petroleum crude oil and other flammable liquids from production to consumption sites. Being different from roadway transport of hazardous materials, a train accident can potentially result in the derailment and release of multiple tank cars, which may result in significant consequences. The prior literature predominantly assumes that the occurrence of multiple tank car releases in a train accident is a series of independent Bernoulli processes, and thus uses the binomial distribution to estimate the total number of tank car releases given the number of tank cars derailing or damaged. This paper shows that the traditional binomial model can incorrectly estimate multiple tank car release probability by magnitudes in certain circumstances, thereby significantly affecting railroad safety and risk analysis. To bridge this knowledge gap, this paper proposes a novel, alternative Correlated Binomial (CB) model that accounts for the possible correlations of multiple tank car releases in the same train. We test three distinct correlation structures in the CB model, and find that they all outperform the conventional binomial model based on empirical tank car accident data. The analysis shows that considering tank car release correlations would result in a significantly improved fit of the empirical data than otherwise. Consequently, it is prudent to consider alternative modeling techniques when analyzing the probability of multiple tank car releases in railroad accidents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Modeling the early-phase redistribution of radiocesium fallouts in an evergreen coniferous forest after Chernobyl and Fukushima accidents.

    Science.gov (United States)

    Calmon, P; Gonze, M-A; Mourlon, Ch

    2015-10-01

    Following the Chernobyl accident, the scientific community gained numerous data on the transfer of radiocesium in European forest ecosystems, including information regarding the short-term redistribution of atmospheric fallout onto forest canopies. In the course of international programs, the French Institute for Radiological Protection and Nuclear Safety (IRSN) developed a forest model, named TREE4 (Transfer of Radionuclides and External Exposure in FORest systems), 15 years ago. Recently published papers on a Japanese evergreen coniferous forest contaminated by Fukushima radiocesium fallout provide interesting and quantitative data on radioactive mass fluxes measured within the forest in the months following the accident. The present study determined whether the approach adopted in the TREE4 model provides satisfactory results for Japanese forests or whether it requires adjustments. This study focused on the interception of airborne radiocesium by forest canopy, and the subsequent transfer to the forest floor through processes such as litterfall, throughfall, and stemflow, in the months following the accident. We demonstrated that TREE4 quite satisfactorily predicted the interception fraction (20%) and the canopy-to-soil transfer (70% of the total deposit in 5 months) in the Tochigi forest. This dynamics was similar to that observed in the Höglwald spruce forest. However, the unexpectedly high contribution of litterfall (31% in 5 months) in the Tochigi forest could not be reproduced in our simulations (2.5%). Possible reasons for this discrepancy are discussed; and sensitivity of the results to uncertainty in deposition conditions was analyzed. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Sensitivity analysis for CORSOR models simulating fission product release in LOFT-LP-FP-2 severe accident experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hoseyni, Seyed Mohsen [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Basic Sciences; Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Young Researchers and Elite Club; Pourgol-Mohammad, Mohammad [Sahand Univ. of Technology, Tabriz (Iran, Islamic Republic of). Dept. of Mechanical Engineering; Yousefpour, Faramarz [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2017-03-15

    This paper deals with simulation, sensitivity and uncertainty analysis of LP-FP-2 experiment of LOFT test facility. The test facility simulates the major components and system response of a pressurized water reactor during a LOCA. MELCOR code is used for predicting the fission product release from the core fuel elements in LOFT LP-FP-2 experiment. Moreover, sensitivity and uncertainty analysis is performed for different CORSOR models simulating release of fission products in severe accident calculations for nuclear power plants. The calculated values for the fission product release are compared under different modeling options to the experimental data available from the experiment. In conclusion, the performance of 8 CORSOR modeling options is assessed for available modeling alternatives in the code structure.

  15. Use of detailed thermochemical databases to model chemical interactions in the Severe Accident codes

    Energy Technology Data Exchange (ETDEWEB)

    Barrachin, M. [IPSN/DRS, CEA Cadarache (France)

    2001-07-01

    For the prevention, mitigation and management of severe accidents, many problems related to core melt have to be solved: fuel degradation, melting and relocation, convection in the core melt(s), coolability of the core melt(s), fission product release, hydrogen production, behavior of the materials of the protective layers, ex-vessel spreading of the core melt(s).. To solve these problems such properties like thermal conductivity, heat capacity, density, viscosity, evaporation or sublimation of melts, the solidification behavior (solid/liquid fraction), the tendency to trap or to release the fission products, the stratification of melts notably metallic and oxide, must be known. However most of these properties are delicate to measure directly at high temperature and/or in the radio-active environment produced by the fission products. Therefore some of them must be derived by calculations from the physical-chemical description of the melt: number of phases, phase compositions, proportions of solids and liquids and their respective oxidation state, miscibility of the liquids, solubility of one phase in another, etc. This information is given by the phase diagrams of the materials in presence. Since more than ten years, IPSN has developed in collaboration with THERMODATA (Grenoble, France) a very detailed thermochemical database for the complex system U-O-Zr-Fe-Ni-La-Ba-Ru-Sr-Si-Mg-Ca-Al-(H-Ar). The direct coupling between the severe accident (SA) Codes and a thermochemical code with its database is not actually possible because of the computer time consuming and the size of the database. For this reason, most of the Severe Accident codes usually have a very simplified description for the phase diagrams which are not in agreement with the status of the art. In this presentation, alternative methodologies are detailed with their respective difficulties, the goal being to build an interface between a thermochemical database and a SA Code and to get a fast, accurate and

  16. Cassini Spacecraft Uncertainty Analysis Data and Methodology Review and Update/Volume 1: Updated Parameter Uncertainty Models for the Consequence Analysis

    Energy Technology Data Exchange (ETDEWEB)

    WHEELER, TIMOTHY A.; WYSS, GREGORY D.; HARPER, FREDERICK T.

    2000-11-01

    Uncertainty distributions for specific parameters of the Cassini General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) Final Safety Analysis Report consequence risk analysis were revised and updated. The revisions and updates were done for all consequence parameters for which relevant information exists from the joint project on Probabilistic Accident Consequence Uncertainty Analysis by the United States Nuclear Regulatory Commission and the Commission of European Communities.

  17. Anthropometric dependence of the response of a thorax FE model under high speed loading: validation and real world accident replication.

    Science.gov (United States)

    Roth, Sébastien; Torres, Fabien; Feuerstein, Philippe; Thoral-Pierre, Karine

    2013-05-01

    Finite element analysis is frequently used in several fields such as automotive simulations or biomechanics. It helps researchers and engineers to understand the mechanical behaviour of complex structures. The development of computer science brought the possibility to develop realistic computational models which can behave like physical ones, avoiding the difficulties and costs of experimental tests. In the framework of biomechanics, lots of FE models have been developed in the last few decades, enabling the investigation of the behaviour of the human body submitted to heavy damage such as in road traffic accidents or in ballistic impact. In both cases, the thorax/abdomen/pelvis system is frequently injured. The understanding of the behaviour of this complex system is of extreme importance. In order to explore the dynamic response of this system to impact loading, a finite element model of the human thorax/abdomen/pelvis system has, therefore, been developed including the main organs: heart, lungs, kidneys, liver, spleen, the skeleton (with vertebrae, intervertebral discs, ribs), stomach, intestines, muscles, and skin. The FE model is based on a 3D reconstruction, which has been made from medical records of anonymous patients, who have had medical scans with no relation to the present study. Several scans have been analyzed, and specific attention has been paid to the anthropometry of the reconstructed model, which can be considered as a 50th percentile male model. The biometric parameters and laws have been implemented in the dynamic FE code (Radioss, Altair Hyperworks 11©) used for dynamic simulations. Then the 50th percentile model was validated against experimental data available in the literature, in terms of deflection, force, whose curve must be in experimental corridors. However, for other anthropometries (small male or large male models) question about the validation and results of numerical accident replications can be raised.

  18. Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

    1997-11-01

    Three uranium hexafluoride-(UF{sub 6}-) specific models--HGSYSTEM/UF{sub 6}, Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF{sub 6} released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF{sub 6}-specific models, using field data on releases of UF{sub 6} and other heavy gases. Predictions from the HGSYSTEM/UF{sub 6} and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF{sub 6}-specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF{sub 6} reaction with water.

  19. Partial least square method for modelling ergonomic risks factors on express bus accidents in the east coast of peninsular west Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Yusof bin [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Gambang 26300 Kuantan, Pahang (Malaysia); Taha, Zahari bin [Faculty of Manufacturing Engineering, Malaysia Pahang, 26600 Pekan, Pahang (Malaysia)

    2015-02-03

    Public, stake holders and authorities in Malaysian government show great concern towards high numbers of passenger’s injuries and passengers fatalities in express bus accident. This paper studies the underlying factors involved in determining ergonomics risk factors towards human error as the reasons in express bus accidents in order to develop an integrated analytical framework. Reliable information about drivers towards bus accident should lead to the design of strategies intended to make the public feel safe in public transport services. In addition there is an analysis of ergonomics risk factors to determine highly ergonomic risk factors which led to accidents. The research was performed in east coast of peninsular Malaysia using variance-based structural equation modeling namely the Partial Least Squares (PLS) regression techniques. A questionnaire survey was carried out at random among 65 express bus drivers operating from the city of Kuantan in Pahang and among 49 express bus drivers operating from the city of Kuala Terengganu in Terengganu to all towns in the east coast of peninsular west Malaysia. The ergonomic risks factors questionnaire is based on demographic information, occupational information, organizational safety climate, ergonomic workplace, physiological factors, stress at workplace, physical fatigue and near miss accidents. The correlation and significant values between latent constructs (near miss accident) were analyzed using SEM SmartPLS, 3M. The finding shows that the correlated ergonomic risks factors (occupational information, t=2.04, stress at workplace, t = 2.81, physiological factor, t=2.08) are significant to physical fatigue and as the mediator to near miss accident at t = 2.14 at p<0.05and T-statistics, t>1.96. The results shows that the effects of physical fatigue due to ergonomic risks factors influence the human error as the reasons in express bus accidents.

  20. Partial least square method for modelling ergonomic risks factors on express bus accidents in the east coast of peninsular west Malaysia

    Science.gov (United States)

    Hashim, Yusof bin; Taha, Zahari bin

    2015-02-01

    Public, stake holders and authorities in Malaysian government show great concern towards high numbers of passenger's injuries and passengers fatalities in express bus accident. This paper studies the underlying factors involved in determining ergonomics risk factors towards human error as the reasons in express bus accidents in order to develop an integrated analytical framework. Reliable information about drivers towards bus accident should lead to the design of strategies intended to make the public feel safe in public transport services. In addition there is an analysis of ergonomics risk factors to determine highly ergonomic risk factors which led to accidents. The research was performed in east coast of peninsular Malaysia using variance-based structural equation modeling namely the Partial Least Squares (PLS) regression techniques. A questionnaire survey was carried out at random among 65 express bus drivers operating from the city of Kuantan in Pahang and among 49 express bus drivers operating from the city of Kuala Terengganu in Terengganu to all towns in the east coast of peninsular west Malaysia. The ergonomic risks factors questionnaire is based on demographic information, occupational information, organizational safety climate, ergonomic workplace, physiological factors, stress at workplace, physical fatigue and near miss accidents. The correlation and significant values between latent constructs (near miss accident) were analyzed using SEM SmartPLS, 3M. The finding shows that the correlated ergonomic risks factors (occupational information, t=2.04, stress at workplace, t = 2.81, physiological factor, t=2.08) are significant to physical fatigue and as the mediator to near miss accident at t = 2.14 at p1.96. The results shows that the effects of physical fatigue due to ergonomic risks factors influence the human error as the reasons in express bus accidents.

  1. Accident: Reminder

    CERN Document Server

    2003-01-01

    There is no left turn to Point 1 from the customs, direction CERN. A terrible accident happened last week on the Route de Meyrin just outside Entrance B because traffic regulations were not respected. You are reminded that when travelling from the customs, direction CERN, turning left to Point 1 is forbidden. Access to Point 1 from the customs is only via entering CERN, going down to the roundabout and coming back up to the traffic lights at Entrance B

  2. ECOLOGICAL CONSEQUENCES REDUCTION FROM AVIATION ACCIDENTS IMPACTS

    Directory of Open Access Journals (Sweden)

    N. I. Nikolaykin

    2016-01-01

    Full Text Available В статье предлагается рассматривать авиационные события как источник аварийно-залпового воздействия на окружающую среду. Приведена классификация видов возникающего загрязнения, анализ проблем при разливе горюче-смазочных материалов на месте падения воздушного судна.Предложена система мер по снижению негативного экологического воздействия на почвы затронутой тер- ритории путем их детоксикации. Обосновано применение углеродных сорбентов. Рекомендованы зависимости для расчета необходимого количества активных углей. Показана рекомендуемая последовательность проведения работ на загрязненной территории.

  3. Research and application on FTA model of chemical accident fuzzy system%化工事故模糊系统FTA模型的研究与应用

    Institute of Scientific and Technical Information of China (English)

    王陈玉书; 张园园; 张巨伟; 尚思思; 刘俊亨

    2013-01-01

    针对化工事故模糊系统,基于三角模糊数和事故树建立事故定量分析模型.运用该模型进行案例分析,确定储油罐体发生火灾爆炸事故的概率分布,指出概率的波动范围、平均事故概率,得出基本事件的模糊重要度,进行模糊重要度排序,明确该化工系统危险源分布的状态,指出导致事故发生的最危险路径,给出该危险路径发生的模糊概率,以上为企业管理人员制定安全措施提供重要的参考依据.该模型对于企业进行事故预测、事故原因分析、制定安全对策、风险投资分析具有重要的意义.%Accident quantitative analysis model for chemical accident fuzzy system based on triangular fuzzy number and fault tree was established. This model was applied to analyzing a case, determining the fire and explosion accident probability distribution of oil tank, pointing out that the fluctuation range of probability and the average accident probability, getting the fuzzy important degree of basic events, sorting fuzzy degree of importance, clearing the state of dangerous source distribution about the chemical system, and pointing out the most dangerous path that causes the accident. All of above provide important reference for corporate executives to develop safety measures. The model is important for accident prediction, analyzing the cause of the accident, developing safety countermeasures and analyzing risk investment.

  4. Consequence modeling of fire on Methane storage tanks in a gas refinery

    Directory of Open Access Journals (Sweden)

    Sara Shahedi ali abadi

    2016-06-01

    Full Text Available Introduction: using fossil fuels, some hazards such as explosion and fire are probable. This study was aimed to consequence modeling of fire on Methane storage tanks in a gas refinery using analyzing the risk, and modeling and evaluating the related consequences. Method: Hazard analysis by PHA was used to choosing the worst-case scenario. Then, causes of the scenario were determined by FTA. After that, consequence modeling by the PHAST software was applied for the consequence analysis. Results: Based on some criteria, the fire of methane gas tank (V-100 was selected as the worst-case scenario at the refinery. The qualitative fault tree showed three factors including mechanical, process, and human failures contribute in gas leakage. The leakage size and weather conditions were effective on the distance of radiation. Using consequence modeling, thermal radiation was considered as the major outcome of the incident. Finally, for outcome evaluating, probit equations were used to quantify losses and the percentage of fatalities due to the methane gas leakage and fire occurrence. The maximum number of fatalities caused by fire was obtained 23 persons. Conclusions: In conclusion, the methane gas vessel in the refinery can be considered as the main center of hazard, therefore the implementation of the safety rules, eliminating mechanical failures, personal protection and education, and Effective measures to prevent and fighting of fire are proposed for decreasing the probable losses and fatalities.

  5. Modeling in fast dynamics of accidents in the primary circuit of PWR type reactors; Modelisation en dynamique rapide d'accidents dans le circuit primaire des reacteurs a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Robbe, M.F

    2003-12-01

    Two kinds of accidents, liable to occur in the primary circuit of a Pressurized Water Reactor and involving fast dynamic phenomena, are analyzed. The Loss Of Coolant Accident (LOCA) is the accident used to define the current PWR. It consists in a large-size break located in a pipe of the primary circuit. A blowdown wave propagates through the circuit. The pressure differences between the different zones of the reactor induce high stresses in the structures of the lower head and may degrade the reactor core. The primary circuit starts emptying from the break opening. Pressure decreases very quickly, involving a large steaming. Two thermal-hydraulic simulations of the blowdown phase of a LOCA are computed with the Europlexus code. The primary circuit is represented by a pipe-model including the hydraulic peculiarities of the circuit. The main differences between both computations concern the kind of reactor, the break location and model, and the initialization of the accidental operation. Steam explosion is a hypothetical severe accident liable to happen after a core melting. The molten part of the core (called corium) falls in the lower part of the reactor. The interaction between the hot corium and the cold water remaining at the bottom of the vessel induces a massive and violent vaporization of water, similar to an explosive phenomenon. A shock wave propagates in the vessel. what can damage seriously the neighbouring structures or drill the vessel. This work presents a synthesis of in-vessel parametrical studies carried out with the Europlexus code, the linkage of the thermal-hydraulic code Mc3d dedicated to the pre-mixing phase with the Europlexus code dealing with the explosion, and finally a benchmark between the Cigalon and Europlexus codes relative to the Vulcano mock-up. (author)

  6. Consequence Based Design. An approach for integrating computational collaborative models (Integrated Dynamic Models) in the building design phase

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer

    affect the design process and collaboration between building designers and simulationists. Within the limits of applying the approach of Consequence based design to five case studies, followed by documentation based on interviews, surveys and project related documentations derived from internal reports...... that secures validity and quality assurance with a simulationist while sustaining autonomous control of building design with the building designer. Consequence based design is defined by the specific use of integrated dynamic models. These models include the parametric capabilities of a visual programming tool...... relies on various advancements in the area of integrated dynamic models. It also relies on the application and test of the approach in practice to evaluate the Consequence based design and the use of integrated dynamic models. As a result, the Consequence based design approach has been applied in five...

  7. Identification of traffic accident risk-prone areas under low lighting conditions

    Directory of Open Access Journals (Sweden)

    K. Ivan

    2015-02-01

    Full Text Available Besides other non-behavioural factors, the low lighting conditions significantly influence the frequency of the traffic accidents in the urban environment. This paper intends to identify the impact of low lighting conditions on the traffic accidents in the city of Cluj-Napoca. The dependence degree between lighting and the number of traffic accidents was analyzed by the Pearson's correlation and the relation between the spatial distribution of traffic accidents and the lighting conditions was determined by the frequency ratio model. The vulnerable areas within the city were identified based on the calculation of the injured persons rate for the 0.5 km2 equally-sized areas uniformly distributed within the study area. The results have shown a strong linear dependence between the low lighting conditions and the number of traffic accidents in terms of three seasonal variations and a high probability of traffic accidents occurrence under the above-mentioned conditions, at the city entrances-exits, which represent also vulnerable areas within the study area. Knowing the linear dependence and the spatial relation between the low lighting and the number of traffic accidents, as well as the consequences induced by their occurrence enabled us to identify the high traffic accident risk areas in the city of Cluj-Napoca.

  8. Identification of traffic accident risk-prone areas under low-light conditions

    Science.gov (United States)

    Ivan, K.; Haidu, I.; Benedek, J.; Ciobanu, S. M.

    2015-09-01

    Besides other non-behavioural factors, low-light conditions significantly influence the frequency of traffic accidents in an urban environment. This paper intends to identify the impact of low-light conditions on traffic accidents in the city of Cluj-Napoca, Romania. The dependence degree between light and the number of traffic accidents was analysed using the Pearson correlation, and the relation between the spatial distribution of traffic accidents and the light conditions was determined by the frequency ratio model. The vulnerable areas within the city were identified based on the calculation of the injury rate for the 0.5 km2 areas uniformly distributed within the study area. The results show a strong linear correlation between the low-light conditions and the number of traffic accidents in terms of three seasonal variations and a high probability of traffic accident occurrence under the above-mentioned conditions at the city entrances/exits, which represent vulnerable areas within the study area. Knowing the linear dependence and the spatial relation between the low light and the number of traffic accidents, as well as the consequences induced by their occurrence, enabled us to identify the areas of high traffic accident risk in Cluj-Napoca.

  9. Environmental Consequences of Wildlife Tourism: The Use of Formalised Qualitative Models

    Directory of Open Access Journals (Sweden)

    Veselý Štěpán

    2015-09-01

    Full Text Available The paper presents a simple qualitative model of environmental consequences of wildlife tourism. Qualitative models use just three values: Positive/Increasing, Zero/Constant and Negative/Decreasing. Such quantifiers of trends are the least information intensive. Qualitative models can be useful, since models of wildlife tourism include such variables as, for example, Biodiversity (BIO, Animals’ habituation to tourists (HAB or Plant composition change (PLA that are sometimes difficult or costly to quantify. Hence, a significant fraction of available information about wildlife tourism and its consequences is not of numerical nature, for example, if HAB is increasing then BIO is decreasing. Such equationless relations are studied in this paper. The model has 10 variables and 20 equationless pairwise interrelations among them. The model is solved and 15 solutions, that is, scenarios are obtained. All qualitative states, including the first and second qualitative derivatives with respect to time, of all variables are specified for each scenario.

  10. Reconstruction of {sup 131}I radioactive contamination in Ukraine caused by the Chernobyl accident using atmospheric transport modelling

    Energy Technology Data Exchange (ETDEWEB)

    Talerko, Nikolai [Scientific Center for Radiation Medicine, 53 Melnikov Street, Kyiv 04050 (Ukraine)]. E-mail: ntalerko@mail.ru

    2005-07-01

    The evaluation of {sup 131}I air and ground contamination field formation in the territory of Ukraine was made using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The {sup 131}I atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The airborne {sup 131}I concentration and ground deposition fields were calculated as the database for subsequent thyroid dose reconstruction for inhabitants of radioactive contaminated regions. The small-scale deposition field variability is assessed using data of {sup 137}Cs detailed measurements in the territory of Ukraine. The obtained results are compared with available data of radioiodine daily deposition measurements made at the network of meteorological stations in Ukraine and data of the assessments of {sup 131}I soil contamination obtained from the {sup 129}I measurements.

  11. Multiplicative models of analysis : a description and the use in analysing accident ratios as a function of hourly traffic volume and road-surface skidding resistance.

    NARCIS (Netherlands)

    Oppe, S.

    1977-01-01

    Accident ratios are analysed with regard to the variables road surface skidding resistance and hourly traffic volume. It is concluded that the multiplicative model describes the data better than the additive model. Moreover that there is no interaction between skidding resistance and traffic volume

  12. Evaluation of the anatomical and functional consequences of repetitive mild cervical contusion using a model of spinal concussion.

    Science.gov (United States)

    Jin, Ying; Bouyer, Julien; Haas, Christopher; Fischer, Itzhak

    2015-09-01

    Spinal cord concussion is characterized by a transient loss of motor and sensory function that generally resolves without permanent deficits. Spinal cord concussions usually occur during vehicular accidents, falls, and sport activity, but unlike brain concussions, have received much less attention despite the potential for repeated injury leading to permanent neurological sequelae. Consequently, there is no consensus regarding decisions related to return to play following an episode of spinal concussion, nor an understanding of the short- and long-term consequences of repeated injury. Importantly, there are no models of spinal concussion to study the anatomical and functional sequelae of single or repeated injury. We have developed a new model of spinal cord concussion focusing on the anatomical and behavioral outcomes of single and repeated injury. Rats received a very mild (50 kdyn, IH impactor) spinal contusion at C5 and were separated into two groups three weeks after the initial injury--C1, which received a second, sham surgery, and C2, which received a second contusion at the same site. To track motor function and recovery, animals received weekly behavioral tests--BBB, CatWalk™, cylinder, and Von Frey. Analysis of locomotor activity by BBB demonstrated that rats rapidly recovered, regaining near-normal function by one week after the first and second injury, which was confirmed using the more detailed CatWalk™ analysis. The cylinder test showed that a single contusion did not induce significant deficits of the affected limb, but that repeated injury resulted in significant alteration in paw preference, with animals favoring the unaffected limb. Intriguingly, Von Frey analysis demonstrated an increased sensitivity in the contralateral hindlimb in the C2 group vs. the C1 group. Anatomical analyses revealed that while the lesion volume of both groups was minimal, the area of spared white matter in the C2 group was significantly reduced 1 and 2mm rostral to

  13. The SAM software system for modeling severe accidents at nuclear power plants equipped with VVER reactors on full-scale and analytic training simulators

    Science.gov (United States)

    Osadchaya, D. Yu.; Fuks, R. L.

    2014-04-01

    The architecture of the SAM software package intended for modeling beyond-design-basis accidents at nuclear power plants equipped with VVER reactors evolving into a severe stage with core melting and failure of the reactor pressure vessel is presented. By using the SAM software package it is possible to perform comprehensive modeling of the entire emergency process from the failure initiating event to the stage of severe accident involving meltdown of nuclear fuel, failure of the reactor pressure vessel, and escape of corium onto the concrete basement or into the corium catcher with retention of molten products in it.

  14. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale U3Si2 Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, K. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, J. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Miao, Y. [Argonne National Lab. (ANL), Argonne, IL (United States); Andersson, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-07-26

    Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced accident tolerance when compared to traditional \\uo~fuel zircaloy clad fuel rods. One of the potential replacement fuels is uranium silicide (\\usi) for its higher thermal conductivity and uranium density. The lower melting temperature is of potential concern during postulated accident conditions. Another disadvantage for \\usi~ is the lack of experimental data under power reactor conditions. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022~\\cite{bragg-sitton_2014} multiscale multiphysics modeling approaches have been used to provide insight into these materials. \\\\ \

  15. Validation of a loss of vacuum accident (LOVA) Computational Fluid Dynamics (CFD) model

    Energy Technology Data Exchange (ETDEWEB)

    Bellecci, C.; Gaudio, P. [EURATOM-Faculty of Engineering, University of Rome ' Tor Vergata' Via del Politecnico 1, 00133 Rome (Italy); Lupelli, I., E-mail: ivan.lupelli@uniroma2.it [EURATOM-Faculty of Engineering, University of Rome ' Tor Vergata' Via del Politecnico 1, 00133 Rome (Italy); Malizia, A. [EURATOM-Faculty of Engineering, University of Rome ' Tor Vergata' Via del Politecnico 1, 00133 Rome (Italy); Porfiri, M.T. [ENEA Nuclear Fusion Tecnologies, Via Enrico Fermi, 45 I-00044 Frascati (Italy); Quaranta, R.; Richetta, M. [EURATOM-Faculty of Engineering, University of Rome ' Tor Vergata' Via del Politecnico 1, 00133 Rome (Italy)

    2011-10-15

    Intense thermal loads in fusion devices occur during plasma disruptions, Edge Localized Modes (ELM) and Vertical Displacement Events (VDE). They will result in macroscopic erosion of the plasma facing materials and consequent accumulation of activated dust into the ITER Vacuum Vessel (VV). A recognized safety issue for future fusion reactors fueled with deuterium and tritium is the generation of sizeable quantities of dust. In case of LOVA, air inlet occurs due to the pressure difference between the atmospheric condition and the internal condition. It causes mobilization of the dust that can exit the VV threatening public safety because it may contain tritium, may be radioactive from activation products, and may be chemically reactive and/or toxic (Sharpe et al.; Sharpe and Humrickhouse). Several experiments have been conducted with STARDUST facility in order to reproduce a low pressurization rate (300 Pa/s) LOVA event in ITER due to a small air leakage for two different positions of the leak, at the equatorial port level and at the divertor port level, in order to evaluate the velocity magnitude in case of a LOVA that is strictly connected with dust mobilization phenomena. A two-dimensional (2D) modelling of STARDUST, made with the CFD commercial code FLUENT, has been carried out. The results of these simulations were compared against the experimental data for CFD code validation. For validation purposes, the CFD simulation data were extracted at the same locations as the experimental data were collected. In this paper, the authors present and discuss the computer-simulation data and compare them with data collected during the laboratory studies at the University of Rome 'Tor Vergata' Quantum Electronics and Plasmas lab.

  16. The radiological assessment system for consequence analysis - RASCAL

    Energy Technology Data Exchange (ETDEWEB)

    Sjoreen, A.L. [Oak Ridge National Lab., TN (United States); Ramsdell, J.V. [Pacific Northwest Lab., Richland, WA (United States); Athey, G.F. [Athey Consulting, Charles Town, WV (United States)] [and others

    1996-04-01

    The Radiological Assessment System for Consequence Analysis, Version 2.1 (RASCAL 2.1) has been developed for use during a response to radiological emergencies. The model estimates doses for comparison with U.S. Environmental Protection Agency (EPA) Protective Action Guides (PAGs) and thresholds for acute health effects. RASCAL was designed to be used by U.S. Nuclear Regulatory Commission (NRC) personnel who report to the site of a nuclear accident to conduct an independent evaluation of dose and consequence projections and personnel who conduct training and drills on emergency responses. It allows consideration of the dominant aspects of the source term, transport, dose, and consequences. RASCAL consists of three computational tools: ST-DOSE, FM-DOSE, and DECAY. ST-DOSE computes source term, atmospheric transport, and dose to man from accidental airborne releases of radionuclides. The source-term calculations are appropriate for accidents at U.S. power reactors. FM-DOSE computes doses from environmental concentrations of radionuclides in the air and on the ground. DECAY computes radiological decay and daughter in-growth. RASCAL 2.1 is a DOS application that can be run under Windows 3.1 and 95. RASCAL has been the starting point for other accident consequence models, notably INTERRAS, an international version of RASCAL, and HASCAL, an expansion of RASCAL that will model radiological, biological, and chemical accidents.

  17. Modeling of the TMI-2 (Three Mile Island Unit-2) accident with MELPROG/TRAC and calculation results for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Motley, F.E.; Jenks, R.P.

    1988-01-01

    Work has been performed to develop a Three Mile Island Unit-2 (TMI-2) simulation model for MELPROG/TRAC capable of predicting the observed plant behavior that took place during the accident of March 1979. A description of the TMI-2 plant model is presented and calculation results through 174 min of the accident are discussed. Using the ICBC boundary conditions, the calculation predicts pressurizer draining and core recovering prior to fuel-rod damage. A parametric calculation (reduced makeup flow) is currently underway and is in better agreement with the observed plant behavior. Efforts are underway to resolve current discrepancies and proceed with an accurate simulation through Phases 3 and 4 of the accident (174-227 min and 227-300 min, respectively). 13 refs., 11 figs., 2 tabs.

  18. Consequences of K Spin in the Preon Model with Preonic Charge

    Science.gov (United States)

    Senju, H.

    1992-11-01

    The symmetry between w2 and c0 (K spin symmetry) is one of important approximate global symmetries in our model. Some consequences of this symmetry are discussed, including the natural existence of cold dark matter with ΩCDM = O(1) and the existence of very massive and quasi-stable hadrons. Implications of K symmetry for CP violations are also discussed.

  19. The Consequences of Ignoring Multilevel Data Structures in Nonhierarchical Covariance Modeling.

    Science.gov (United States)

    Julian, Marc W.

    2001-01-01

    Examined the effects of ignoring multilevel data structures in nonhierarchical covariance modeling using a Monte Carlo simulation. Results suggest that when the magnitudes of intraclass correlations are less than 0.05 and the group size is small, the consequences of ignoring the data dependence within the multilevel data structures seem to be…

  20. Modelling the consequences of increasing bioenergy demand on land and feed use

    NARCIS (Netherlands)

    Banse, M.A.H.; Tabeau, A.A.; Meijl, van H.; Woltjer, G.B.

    2010-01-01

    The aim of this paper is to show the consequences of a model extension towards the presentation of by-product in the production of biofuels. By-products can be used as a substitute for feed grain use in livestock production. A boost in biofuel production will also show a strong increase in the

  1. Development of an in vitro porcine aorta model to study the stability of stent grafts in motor vehicle accidents.

    Science.gov (United States)

    Darvish, Kurosh; Shafieian, Mehdi; Romanov, Vasily; Rotella, Vittorio; Salvatore, Michael D; Blebea, John

    2009-04-01

    Endovascular stent grafts for the treatment of thoracic aortic aneurysms have become increasingly utilized and yet their locational stability in moderate chest trauma is unknown. A high speed impact system was developed to study the stability of aortic endovascular stent grafts in vitro. A straight segment of porcine descending aorta with stent graft was constrained in a custom-made transparent urethane casing. The specimen was tested in a novel impact system at an anterior inclination of 45 deg and an average deceleration of 55 G, which represented a frontal automobile crash. Due to the shock of the impact, which was shown to be below the threshold of aortic injury, the stent graft moved 0.6 mm longitudinally. This result was repeatable. The presented experimental model may be helpful in developing future grafts to withstand moderate shocks experienced in motor vehicle accidents or other dynamic loadings of the chest.

  2. Verification and Validation of Neutronic/Thermalhydraulic 3D-Time Dependent Model for Treatment of Super-critical States of Light water Research Reactors Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Khaled, S.M. [Department of Basic Studies and Sciences, Community College, University of Tabuk, Tabuk (Saudi Arabia); Department of Mathematics, Faculty of Sciences, Helwan University, Cairo (Egypt)

    2015-07-01

    This work presents the Verification and testing both the neutronic and thermal-hydraulics response of the positive reactivity-initiated power excursion accidents in small light water research reactors. Some research reactors have to build its own severe accidents code system. In this sense, a 3D space-time-dependent neutron diffusion models with thermal hydraulic feedback have been introduced, compared and tested both experimentally at criticality 14-cent and theoretically up to 1.5 $ with a number of similar codes. The results shows that no expected core failure or moderator boiling. (author)

  3. Self-reported accidents

    DEFF Research Database (Denmark)

    Møller, Katrine Meltofte; Andersen, Camilla Sloth

    2016-01-01

    The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals.......The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals....

  4. Multi-physics modelling in the frame of the DRACCAR code development and its application to spent-fuel pool draining accidents

    Energy Technology Data Exchange (ETDEWEB)

    Jacq, F.; Luze, O. de; Guillard, G.; Bascou, S. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France)

    2013-07-01

    To meet the simulation needs of its LOCA R and D program, the IRSN is developing a multi-pin computational tool named DRACCAR. In order to realistically describe the behavior of the reactor core during a Loss Of Coolant Accident (LOCA), modeling has to take into account many coupled phenomena such as thermics (heat generation, radiation, convection and conduction), hydraulics (multi dimensional 1-3 phase flow, shrinkage), mechanics (thermal dilatation, creep, embrittlement) and chemistry (oxidation, oxygen diffusion, hydriding,..). This paper presents several aspects of the DRACCAR code abilities: investigation of the bundle rods strain during a LOCA transient, checking of the thermalhydraulics during reflooding of a partially ballooned bundle, and application to spent-fuel-pool draining accidents in the case of a propagation of the burn front in a typical non axis-symmetrical situation for the thermal heat exchanges which are driving the accident. (orig.)

  5. Modelling of Zry-4 cladding oxidation by air, under severe accident conditions using the MAAP4 code

    Energy Technology Data Exchange (ETDEWEB)

    Beuzet, Emilie, E-mail: emilie.beuzet@edf.f [EDF R and D, 1 Avenue du General de Gaulle, F-92140 Clamart (France); Lamy, Jean-Sylvestre, E-mail: jean-sylvestre.lamy@edf.f [EDF R and D, 1 Avenue du General de Gaulle, F-92140 Clamart (France); Bretault, Armelle, E-mail: armelle.bretault@edf.f [EDF R and D, 1 Avenue du General de Gaulle, F-92140 Clamart (France); Simoni, Eric, E-mail: simoni@ipno.in2p3.f [Institut de Physique Nucleaire, Universite Paris Sud XI, F-91406 Orsay (France)

    2011-04-15

    In a nuclear power plant, a potential risk in some low probability situations in severe accidents is air ingress into the vessel. Air is a highly oxidizing atmosphere that can lead to an enhanced core oxidation and degradation affecting the release of Fission Products (FP), especially increasing that of ruthenium. This FP is of particular importance because of its high radio-toxicity and its ability to form highly volatile oxides. Oxygen affinity is decreasing between Zircaloy cladding, fuel and ruthenium inclusions in the fuel. It is consequently of great need to understand the phenomena governing cladding oxidation by air as a prerequisite for the source term issues. A review of existing data in the field of Zircaloy-4 oxidation in air-containing atmosphere shows that this phenomenon is quantitatively well understood. The cladding oxidation process can be divided into two kinetic regimes separated by a breakaway transition. Before transition, a protective dense zirconia scale grows following a solid state diffusion-limited regime for which experimental data are well fitted by a parabolic time dependence. For a given thickness, which depends mainly on temperature and the extent of pre-oxidation in steam, the dense scale can potentially breakdown. In case of breakaway combined with oxygen starvation, cladding oxidation can then be much faster because of the combined action of oxygen and nitrogen through a complex self sustaining nitriding-oxidation process. A review of the pre-existing correlations used to simulate zirconia scale growth under air atmospheres shows a high degree of variation from parabolic to accelerated time dependence. Variations also exist in the choice of the breakaway parameter based on zirconia phase change or oxide thickness. Several correlations and breakaway parameters found in the literature were implemented in the MAAP4.07 Severe Accident code. They were assessed by simulation of the QUENCH-10 test, which is a semi-integral test designed

  6. A two-temperature model for thermoelectric effects and its consequences in practical applications

    Science.gov (United States)

    Sellitto, A.

    2015-12-01

    In recent papers, a two-temperature model for thermoelectric effects has been introduced. That model is able to account for the difference in phonon and electron temperature and may open new lines of research in thermoelectricity. Here, we perform a scrutiny of that model in order to check its physical standing. We further provide some useful characteristic numbers which may be used in practical applications in order to reduce to a simpler level the analysis. The consequences of that model on the usual Kelvin relations are pointed out, as well.

  7. Economic models of compensation for damages caused by nuclear accidents: some lessons for the revision of the Paris and Vienna Conventions

    Energy Technology Data Exchange (ETDEWEB)

    Faure, Michael G. [Limburg Univ., Maastricht (Netherlands). Faculty of Law

    1995-12-31

    Alternative systems of compensation for damages caused by nuclear accidents have been proposed. In respect, the question merits attention to whether these alternative models of compensation discussed in the economic literature could be implemented when discussing the revision of the Paris and Vienna Conventions. 55 refs., 1 tab.

  8. PRYMA-TO: A model of radionuclide transfer from air into food stuff. Test with data from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Olivares, A.; Carrasco, E.; Suanez, A.; Josep, L.

    1994-07-01

    This report describes a dynamical model developed in the Environmental Institute of the CIEMAT. Its aims are the calculation of the integrated as well as time-dependent concentrations of ''131l and ''137Cs over time in soils, in forage pasture (or other vegetation species), and in milk and meat. The source contamination is assumed to come from a radioactive cloud confined in the atmospheric mixing layer. Data monitored in different locations the days following the Chernobyl accident have been used. The model was tested against post-Chernobyl data from 13 locations around the world, in the framework of the A4 exercise from the BIOMOVS program (Biospheric Models Validation Studies). The performance of the model is illustrated in 9 scenarios which have been chosen of these 13 because they have more information or they are better described. Default Probability Density Functions for the main parameters used by the model have been obtained by statistical processing of some post-Chernobyl evidence. (Author) 30 refs.

  9. Soils apart from equilibrium – consequences for soil carbon balance modelling

    Directory of Open Access Journals (Sweden)

    T. Wutzler

    2006-10-01

    Full Text Available Many projections of the soil carbon sink or source are based on kinetically defined carbon pool models. Parameters of these models are often determined in a way that the steady state of the model matches observed carbon stocks. The underlying simplifying assumption is that observed carbon stocks are near equilibrium. This assumption is challenged by observations of very old soils that do still accumulate carbon. In this modelling study we explored the consequences of the case where soils are apart from equilibrium. Calculation of equilibrium states of soils that are currently accumulating small amounts of carbon were performed using the Yasso model. It was found that already very small current accumulation rates cause big changes in theoretical equilibrium stocks, which can virtually approach infinity. We conclude that soils that have been disturbed several centuries ago are not in equilibrium but in a transient state because of the slowly ongoing accumulation of the slowest pool. A first consequence is that model calibrations to current carbon stocks that assume equilibrium state, overestimate the decay rate of the slowest pool. A second consequence is that spin-up runs (simulations until equilibrium overestimate stocks of recently disturbed sites. In order to account for these consequences, we propose a transient correction. This correction prescribes a lower decay rate of the slowest pool and accounts for disturbances in the past by decreasing the spin-up-run predicted stocks to match an independent estimate of current soil carbon stocks. Application of this transient correction at a Central European beech forest site with a typical disturbance history resulted in an additional carbon fixation of 5.7±1.5 tC/ha within 100 years. Carbon storage capacity of forest soils is potentially much higher than currently assumed. Simulations that do not adequately account for the transient state of soil carbon stocks neglect a substantial amount of

  10. A SCOPING STUDY: Development of Probabilistic Risk Assessment Models for Reactivity Insertion Accidents During Shutdown In U.S. Commercial Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    S. Khericha

    2011-06-01

    This report documents the scoping study of developing generic simplified fuel damage risk models for quantitative analysis from inadvertent reactivity insertion events during shutdown (SD) in light water pressurized and boiling water reactors. In the past, nuclear fuel reactivity accidents have been analyzed both mainly deterministically and probabilistically for at-power and SD operations of nuclear power plants (NPPs). Since then, many NPPs had power up-rates and longer refueling intervals, which resulted in fuel configurations that may potentially respond differently (in an undesirable way) to reactivity accidents. Also, as shown in a recent event, several inadvertent operator actions caused potential nuclear fuel reactivity insertion accident during SD operations. The set inadvertent operator actions are likely to be plant- and operation-state specific and could lead to accident sequences. This study is an outcome of the concern which arose after the inadvertent withdrawal of control rods at Dresden Unit 3 in 2008 due to operator actions in the plant inadvertently three control rods were withdrawn from the reactor without knowledge of the main control room operator. The purpose of this Standardized Plant Analysis Risk (SPAR) Model development project is to develop simplified SPAR Models that can be used by staff analysts to perform risk analyses of operating events and/or conditions occurring during SD operation. These types of accident scenarios are dominated by the operator actions, (e.g., misalignment of valves, failure to follow procedures and errors of commissions). Human error probabilities specific to this model were assessed using the methodology developed for SPAR model human error evaluations. The event trees, fault trees, basic event data and data sources for the model are provided in the report. The end state is defined as the reactor becomes critical. The scoping study includes a brief literature search/review of historical events, developments of

  11. Influence of the meteorological input on the atmospheric transport modelling with FLEXPART of radionuclides from the Fukushima Daiichi nuclear accident.

    Science.gov (United States)

    Arnold, D; Maurer, C; Wotawa, G; Draxler, R; Saito, K; Seibert, P

    2015-01-01

    In the present paper the role of precipitation as FLEXPART model input is investigated for one possible release scenario of the Fukushima Daiichi accident. Precipitation data from the European Center for Medium-Range Weather Forecast (ECMWF), the NOAA's National Center for Environmental Prediction (NCEP), the Japan Meteorological Agency's (JMA) mesoscale analysis and a JMA radar-rain gauge precipitation analysis product were utilized. The accident of Fukushima in March 2011 and the following observations enable us to assess the impact of these precipitation products at least for this single case. As expected the differences in the statistical scores are visible but not large. Increasing the ECMWF resolution of all the fields from 0.5° to 0.2° rises the correlation from 0.71 to 0.80 and an overall rank from 3.38 to 3.44. Substituting ECMWF precipitation, while the rest of the variables remains unmodified, by the JMA mesoscale precipitation analysis and the JMA radar gauge precipitation data yield the best results on a regional scale, specially when a new and more robust wet deposition scheme is introduced. The best results are obtained with a combination of ECMWF 0.2° data with precipitation from JMA mesoscale analyses and the modified wet deposition with a correlation of 0.83 and an overall rank of 3.58. NCEP-based results with the same source term are generally poorer, giving correlations around 0.66, and comparatively large negative biases and an overall rank of 3.05 that worsens when regional precipitation data is introduced.

  12. Incorporating real-time traffic and weather data to explore road accident likelihood and severity in urban arterials.

    Science.gov (United States)

    Theofilatos, Athanasios

    2017-06-01

    The effective treatment of road accidents and thus the enhancement of road safety is a major concern to societies due to the losses in human lives and the economic and social costs. The investigation of road accident likelihood and severity by utilizing real-time traffic and weather data has recently received significant attention by researchers. However, collected data mainly stem from freeways and expressways. Consequently, the aim of the present paper is to add to the current knowledge by investigating accident likelihood and severity by exploiting real-time traffic and weather data collected from urban arterials in Athens, Greece. Random Forests (RF) are firstly applied for preliminary analysis purposes. More specifically, it is aimed to rank candidate variables according to their relevant importance and provide a first insight on the potential significant variables. Then, Bayesian logistic regression as well finite mixture and mixed effects logit models are applied to further explore factors associated with accident likelihood and severity respectively. Regarding accident likelihood, the Bayesian logistic regression showed that variations in traffic significantly influence accident occurrence. On the other hand, accident severity analysis revealed a generally mixed influence of traffic variations on accident severity, although international literature states that traffic variations increase severity. Lastly, weather parameters did not find to have a direct influence on accident likelihood or severity. The study added to the current knowledge by incorporating real-time traffic and weather data from urban arterials to investigate accident occurrence and accident severity mechanisms. The identification of risk factors can lead to the development of effective traffic management strategies to reduce accident occurrence and severity of injuries in urban arterials. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

  13. Exploring Environmental Effects of Accidents During Marine Transport of Dangerous Goods by Use of Accident Descriptions

    DEFF Research Database (Denmark)

    Rømer, Hans Gottberg; Haastrup, P.; Petersen, H J Styhr

    1996-01-01

    On the basis of 1776 descriptions of water transport accidents involving dangerous goods, environmental problems in connection with releases of this kind are described and discussed. It was found that most detailed descriptions of environmental consequences concerned oil accidents, although most...

  14. Road characteristics and bicycle accidents.

    Science.gov (United States)

    Nyberg, P; Björnstig, U; Bygren, L O

    1996-12-01

    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  15. Modeling of leachable 137Cs in throughfall and stemflow for Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident.

    Science.gov (United States)

    Loffredo, Nicolas; Onda, Yuichi; Kawamori, Ayumi; Kato, Hiroaki

    2014-09-15

    The Fukushima accident dispersed significant amounts of radioactive cesium (Cs) in the landscape. Our research investigated, from June 2011 to November 2013, the mobility of leachable Cs in forests canopies. In particular, (137)Cs and (134)Cs activity concentrations were measured in rainfall, throughfall, and stemflow in broad-leaf and cedar forests in an area located 40 km from the power plant. Leachable (137)Cs loss was modeled by a double exponential (DE) model. This model could not reproduce the variation in activity concentration observed. In order to refine the DE model, the main physical measurable parameters (rainfall intensity, wind velocity, and snowfall occurrence) were assessed, and rainfall was identified as the dominant factor controlling observed variation. A corrective factor was then developed to incorporate rainfall intensity in an improved DE model. With the original DE model, we estimated total (137)Cs loss by leaching from canopies to be 72 ± 4%, 67 ± 4%, and 48 ± 2% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. In contrast, with the improved DE model, the total (137)Cs loss by leaching was estimated to be 34 ± 2%, 34 ± 2%, and 16 ± 1% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. The improved DE model corresponds better to observed data in literature. Understanding (137)Cs and (134)Cs forest dynamics is important for forecasting future contamination of forest soils around the FDNPP. It also provides a basis for understanding forest transfers in future potential nuclear disasters.

  16. Internal Flow Thermal/Fluid Modeling of STS-107 Port Wing in Support of the Columbia Accident Investigation Board

    Science.gov (United States)

    Sharp, John R.; Kittredge, Ken; Schunk, Richard G.

    2003-01-01

    As part of the aero-thermodynamics team supporting the Columbia Accident Investigation Board (CAB), the Marshall Space Flight Center was asked to perform engineering analyses of internal flows in the port wing. The aero-thermodynamics team was split into internal flow and external flow teams with the support being divided between shorter timeframe engineering methods and more complex computational fluid dynamics. In order to gain a rough order of magnitude type of knowledge of the internal flow in the port wing for various breach locations and sizes (as theorized by the CAB to have caused the Columbia re-entry failure), a bulk venting model was required to input boundary flow rates and pressures to the computational fluid dynamics (CFD) analyses. This paper summarizes the modeling that was done by MSFC in Thermal Desktop. A venting model of the entire Orbiter was constructed in FloCAD based on Rockwell International s flight substantiation analyses and the STS-107 reentry trajectory. Chemical equilibrium air thermodynamic properties were generated for SINDA/FLUINT s fluid property routines from a code provided by Langley Research Center. In parallel, a simplified thermal mathematical model of the port wing, including the Thermal Protection System (TPS), was based on more detailed Shuttle re-entry modeling previously done by the Dryden Flight Research Center. Once the venting model was coupled with the thermal model of the wing structure with chemical equilibrium air properties, various breach scenarios were assessed in support of the aero-thermodynamics team. The construction of the coupled model and results are presented herein.

  17. [Mobbing: a meta-analysis and integrative model of its antecedents and consequences].

    Science.gov (United States)

    Topa Cantisano, Gabriela; Depolo, Marco; Morales Domínguez, J Francisco

    2007-02-01

    Although mobbing has been extensively studied, empirical research has not led to firm conclusions regarding its antecedents and consequences, both at personal and organizational levels. An extensive literature search yielded 86 empirical studies with 93 samples. The matrix correlation obtained through meta-analytic techniques was used to test a structural equation model. Results supported hypotheses regarding organizational environmental factors as main predictors of mobbing.

  18. A Simplified Approach to Estimate the Urban Expressway Capacity after Traffic Accidents Using a Micro-Simulation Model

    Directory of Open Access Journals (Sweden)

    Hong Chen

    2013-01-01

    Full Text Available Based on the decomposition of the evolution processes of the urban expressway capacity after traffic accidents and the influence factors analysis, an approach for estimating the capacity has been proposed. Firstly, the approach introduces the Decision Tree ID algorithm, solves the accident delay time of different accident types by the Information Gain Value, and determines congestion dissipation time by the Traffic Flow Wave Theory. Secondly, taking the accident delay time as the observation cycle, the maximum number of the vehicles through the accident road per unit time was considered as its capacity. Finally, the attenuation simulation of the capacity for different accident types was calculated by the VISSIM software. The simulation results suggest that capacity attenuation of vehicle anchor is minimal and the rate is 30.074%; the next is vehicles fire, rear-end, and roll-over, and the rate is 38.389%, 40.204%, and 43.130%, respectively; the capacity attenuation of vehicle collision is the largest, and the rate is 50.037%. Moreover, the further research shows that the accident delay time is proportional to congestion dissipation time, time difference, and the ratio between them, but it is an inverse relationship with the residual capacity of urban expressway.

  19. Modelling the global atmospheric transport and deposition of radionuclides from the Fukushima Dai-ichi nuclear accident

    Science.gov (United States)

    Christoudias, T.; Lelieveld, J.

    2013-02-01

    We modeled the global atmospheric dispersion and deposition of radionuclides released from the Fukushima Dai-ichi nuclear power plant accident. The EMAC atmospheric chemistry - general circulation model was used, with circulation dynamics nudged towards ERA-Interim reanalysis data. We applied a resolution of approximately 0.5 degrees in latitude and longitude (T255). The model accounts for emissions and transport of the radioactive isotopes 131I and 137Cs, and removal processes through precipitation, particle sedimentation and dry deposition. In addition, we simulated the release of 133Xe, a noble gas that can be regarded as a passive transport tracer of contaminated air. The source terms are based on Chino et al. (2011) and Stohl et al. (2012); especially the emission estimates of 131I are associated with a high degree of uncertainty. The calculated concentrations have been compared to station observations by the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO). We calculated that about 80% of the radioactivity from Fukushima which was released to the atmosphere deposited into the Pacific Ocean. In Japan a large inhabited land area was contaminated by more than 40 kBq m-2. We also estimated the inhalation and 50-year dose by 137Cs, 134Cs and 131I to which the people in Japan are exposed.

  20. Accident history, risk perception and traffic safe behaviour.

    Science.gov (United States)

    Ngueutsa, Robert; Kouabenan, Dongo Rémi

    2017-09-01

    This study clarifies the associations between accident history, perception of the riskiness of road travel and traffic safety behaviours by taking into account the number and severity of accidents experienced. A sample of 525 road users in Cameroon answered a questionnaire comprising items on perception of risk, safe behaviour and personal accident history. Participants who reported involvement in more than three accidents or involvement in a severe accident perceived road travel as less risky and also reported behaving less safely compared with those involved in fewer, or less severe accidents. The results have practical implications for the prevention of traffic accidents. Practitioner Summary: The associations between accident history, perceived risk of road travel and safe behaviour were investigated using self-report questionnaire data. Participants involved in more than three accidents, or in severe accidents, perceived road travel as less risky and also reported more unsafe behaviour compared with those involved in fewer, or less severe accidents. Campaigns targeting people with a less serious, less extensive accident history should aim to increase awareness of hazards and the potential severity of their consequences, as well as emphasising how easy it is to take the recommended preventive actions. Campaigns targeting those involved in more frequent accidents, and survivors of serious accidents, should address feelings of invulnerability and helplessness.

  1. Regression model analysis of the decreasing trend of cesium-137 concentration in the atmosphere since the Fukushima accident.

    Science.gov (United States)

    Kitayama, Kyo; Ohse, Kenji; Shima, Nagayoshi; Kawatsu, Kencho; Tsukada, Hirofumi

    2016-11-01

    The decreasing trend of the atmospheric (137)Cs concentration in two cities in Fukushima prefecture was analyzed by a regression model to clarify the relation between the parameter of the decrease in the model and the trend and to compare the trend with that after the Chernobyl accident. The (137)Cs particle concentration measurements were conducted in urban Fukushima and rural Date sites from September 2012 to June 2015. The (137)Cs particle concentrations were separated in two groups: particles of more than 1.1 μm aerodynamic diameters (coarse particles) and particles with aerodynamic diameter lower than 1.1 μm (fine particles). The averages of the measured concentrations were 0.1 mBq m(-3) in Fukushima and Date sites. The measured concentrations were applied in the regression model which decomposed them into two components: trend and seasonal variation. The trend concentration included the parameters for the constant and the exponential decrease. The parameter for the constant was slightly different between the Fukushima and Date sites. The parameter for the exponential decrease was similar for all the cases, and much higher than the value of the physical radioactive decay except for the concentration in the fine particles at the Date site. The annual decreasing rates of the (137)Cs concentration evaluated by the trend concentration ranged from 44 to 53% y(-1) with average and standard deviation of 49 ± 8% y(-1) for all the cases in 2013. In the other years, the decreasing rates also varied slightly for all cases. These indicated that the decreasing trend of the (137)Cs concentration was nearly unchanged for the location and ground contamination level in the three years after the accident. The (137)Cs activity per aerosol particle mass also decreased with the same trend as the (137)Cs concentration in the atmosphere. The results indicated that the decreasing trend of the atmospheric (137)Cs concentration was related with the reduction of the (137)Cs

  2. 二次交通事故Duffing振子模型研究%Research on Duffing Oscillator Model of Secondary Traffic Accident

    Institute of Scientific and Technical Information of China (English)

    张文会; 李平

    2011-01-01

    为了揭示二次交通事故的演变特性,预防二次交通事故的发生,在描述Duffing振子模型的基础上,分析二次交通事故的混沌特性,并建立混沌模型.在仿真环境下,改变模型参数值,得到系统出现周期振荡状态和混沌状态的系统结构条件,并绘制出相平面图和根轨迹图.实例分析结果表明,Duffing振子模型可用于二次交通事故演变过程分析,仿真结果为采取有效的二次交通事故预防措施提供了理论依据.%In order to discover evolution of secondary traffic accidents and prevent from secondary traffic accidents, chaos characteristics of secondary traffic accidents are analyzed based on describing Duffing oscillator model. Afterwards, chaos model is established. By means of simulation, parameters values in chaos model are changed to obtain system constructions when periodic oscillation and chaos state occur. The phase plane and root locus diagrams are drawn. Case study shows that it is feasible to apply Duffing equation to analyze evolution of secondary traffic accidents. Simulation results provide theory conference for taking effective measurements to prevent from secondary traffic accidents.

  3. Quantifying the risk of extreme aviation accidents

    Science.gov (United States)

    Das, Kumer Pial; Dey, Asim Kumer

    2016-12-01

    Air travel is considered a safe means of transportation. But when aviation accidents do occur they often result in fatalities. Fortunately, the most extreme accidents occur rarely. However, 2014 was the deadliest year in the past decade causing 111 plane crashes, and among them worst four crashes cause 298, 239, 162 and 116 deaths. In this study, we want to assess the risk of the catastrophic aviation accidents by studying historical aviation accidents. Applying a generalized Pareto model we predict the maximum fatalities from an aviation accident in future. The fitted model is compared with some of its competitive models. The uncertainty in the inferences are quantified using simulated aviation accident series, generated by bootstrap resampling and Monte Carlo simulations.

  4. Monte Carlo modeling of beta-radiometer device used to measure milk contaminated as a result of the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Khrutchinsky, A.; Kutsen, S. [Research Institute for Nuclear Problems, 11 Bobruiskaya Street, Minsk 220050 (Belarus); Minenko, V. [Belarusian Medical Academy of Post-Graduate Education, 3 Brovki Street, Minsk 220714 (Belarus); Zhukova, O. [Center of Radiation Control and Environment Monitoring, 110A Nezalezhnosti Avenue, Minsk 220023 (Belarus); Luckyanov, N.; Bouville, A. [DHHS, NIH, National Cancer Institute, Division of Cancer Epidemiology and Genetics, 6120 Executive Blvd, EPS 7100, Bethesda, MD 20892 (United States); Drozdovitch, V. [DHHS, NIH, National Cancer Institute, Division of Cancer Epidemiology and Genetics, 6120 Executive Blvd, EPS 7100, Bethesda, MD 20892 (United States)], E-mail: drozdovv@mail.nih.gov

    2009-06-15

    This paper presents results of Monte Carlo modeling of the beta-radiometer device with Geiger-Mueller detector used in Belarus and Russia to measure the radioactive contamination of milk after the Chernobyl accident. This type of detector, which is not energy selective, measured the total beta-activity of the radionuclide mix. A mathematical model of the beta-radiometer device, namely DP-100, was developed, and the calibration factors for the different radionuclides that might contribute to the milk contamination were calculated. The estimated calibration factors for {sup 131}I, {sup 137}Cs, {sup 134}Cs, {sup 90}Sr, {sup 144}Ce, and {sup 106}Ru reasonably agree with calibration factors determined experimentally. The calculated calibration factors for {sup 132}Te, {sup 132}I, {sup 133}I, {sup 136}Cs, {sup 89}Sr, {sup 103}Ru, {sup 140}Ba, {sup 140}La, and {sup 141}Ce had not been previously determined experimentally. The obtained results allow to derive the activity of specific radionuclides, in particular {sup 131}I, from the results of the total beta-activity measurements in milk. Results of this study are important for the purposes of retrospective dosimetry that uses measurements of radioactivity in environmental samples performed with beta-radiometer devices.

  5. Measurement and Exploration of Individual Beliefs About the Consequences of Building Information Modelling Use

    DEFF Research Database (Denmark)

    Davies, Richard; Harty, Chris

    2013-01-01

    expectancy, effort expectancy, social influence, facilitating conditions, compatibility, and attitude toward using technology were adapted from existing measures. In an analysis of responses from 762 construction employees the scales showed acceptable measurement properties. Expectations about......Information and communication technology (ICT) is becoming increasingly important in construction although the rate of adoption is considered slow and the industry faces specific implementation challenges. Mainstream information systems research has shown that individuals’ beliefs and expectations...... of the consequences of ICT use predict subsequent usage. We describe the development of scales to measure beliefs about the consequences of building information modelling (BIM) and their use in a survey of employees of a large construction contracting organization in the United Kingdom. Scales for performance...

  6. Knowledge, transparency, refutability, and consequences: Using models to evaluate geologic repositories

    Science.gov (United States)

    Hill, M. C.; Kavetski, D.; Clark, M. P.; Ye, M.; Tiedeman, C. R.; Arabi, M.; Lu, D.

    2012-04-01

    Current knowledge of a geologic repository includes knowledge about data and their errors; knowledge about possible physical, chemical, and biological processes, and their interactions; knowledge about possible hydrologic and geologic frameworks; knowledge about past and future changes in system dynamics and characteristics; and knowledge about potential future development and use of the repository. Model development and analysis methods ideally integrate all of this knowledge, produce the transparency and refutability acknowledged as necessary to useful models of any environmental system; and provide clear understanding of consequences for the geologic repository, including quantification of uncertainty. Yet many model development and analysis methods fail to achieve this goal. For example, many methods fail to properly account for data error and spend many model runs exploring unrealistic error assumptions that are rarely clearly presented to modelers and model users. Many methods expend huge computer resources to address nearly pathologic model nonlinearities which are often programming and numerical artifacts that fail to represent the intended system behavior. Finally, many methods are unfamiliar to people using model results so that transparency and refutability is not achieved by those most in need of understanding likely consequences. This work suggests that ideas for including data error (including epistemic error) in model development and analysis, referred to as error-based weighting, and ideas about addressing nonlinearity, referred to as robust models, can be used to greatly improve model transparency and refutability, and achieve greater and more defensible long-term understanding of system dynamics and consequences for geologic repositories. This talk will discuss error-based weighting and robust models, and outline a model development and analysis approach that uses 10s to 100s of model runs instead of the 1,000s to 100,000s of runs required by many

  7. Validation of GAMMA+ model for Evaluating Heat Transfer of VHTR core in Accident Conditions by CFD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dongho; Yoon, Sujong; Park, Gooncherl; Cho, Hyoungkyu [Seoul National Univ., Seoul (Korea, Republic of)

    2013-05-15

    KAERI has established a plan to demonstrate massive production of hydrogen using a VHTR by the early 2020s. In addition the GAMMA+ code is developed to analyze VHTR thermo-fluid transients at KAERI. One of the candidate reactor designs for VHTR is prismatic modular reactor (PMR), of which reference reactor is the 600MWth GT-MHR. This type of reactor has a passive safety system. During the High Pressure Conduction Cooling (HPCC) or Low Pressure Conduction Cooling (LPCC) accident, the core heats up by decay heat and then starts to cool down by conduction and radiation cooling to the Reactor Cavity Cooling System (RCCS) through the prismatic core. In this mechanism, the solid conduction occurs in graphite and fuel blocks, and the gas conduction and radiation occurs in coolant holes and bypass gaps. It is important to predict conduction and radiation heat transfer in the core for safety analysis. Effective thermal conductivity is derived by Maxwell's far-field methodology Radiation effect is expressed as corresponding conductivity and added to gas conductivity. In this study, ETC model used in GAMMA+ code is validated with the commercial CFD code, CFX-13. In this study, the effective thermal conductivity model of the GAMMA+ was evaluated by comparison of CFD analysis. The CFD analysis was conducted for various numbers and volume fractions of coolant holes and temperatures. Although slight disagreement was shown for the cases run with small number of holes, the result of GAMMA+ model is accurate for the large numbers of holes sufficiently. Since there are 102 coolant holes and 210 fuel holes in a fuel block, it is concluded that GAMMA+ model is proper formula for predicting effective thermal conductivity of the VHTR fuel block. However, in high temperature region above 500 .deg. C, the GAMMA+ model underestimates the effective thermal conductivity since radiation heat transfer is not reflected precisely. Further researches on it seem to be necessary.

  8. Overview of lower length scale model development for accident tolerant fuels regarding U3Si2 fuel and FeCrAl cladding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Laboratory

    2016-09-01

    U3Si2 and FeCrAl have been proposed as fuel and cladding concepts, respectively, for accident tolerance fuels with higher tolerance to accident scenarios compared to UO2. However, a lot of key physics and material properties regarding their in-pile performance are yet to be explored. To accelerate the understanding and reduce the cost of experimental studies, multiscale modeling and simulation are used to develop physics-based materials models to assist engineering scale fuel performance modeling. In this report, the lower-length-scale efforts in method and material model development supported by the Accident Tolerance Fuel (ATF) high-impact-problem (HIP) under the NEAMS program are summarized. Significant progresses have been made regarding interatomic potential, phase field models for phase decomposition and gas bubble formation, and thermal conductivity for U3Si2 fuel, and precipitation in FeCrAl cladding. The accomplishments are very useful by providing atomistic and mesoscale tools, improving the current understanding, and delivering engineering scale models for these two ATF concepts.

  9. Internal dose assessment due to large area contamination: Main lessons drawn from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Andrasi, A. [KFKI Atomic Energy Research Inst., Budapest (Hungary)

    1997-03-01

    The reactor accident at Chernobyl in 1986 beside its serious and tragic consequences provided also an excellent opportunity to check, test and validate all kind of environmental models and calculation tools which were available in the emergency preparedness systems of different countries. Assessment of internal and external doses due to the accident has been carried out for the population all over Europe using different methods. Dose predictions based on environmental model calculation considering various pathways have been compared with those obtained by more direct monitoring methods. One study from Hungary and one from the TAEA is presented shortly. (orig./DG)

  10. Simulation of the Lower Head Boiling Water Reactor Vessel in a Severe Accident

    Directory of Open Access Journals (Sweden)

    Alejandro Nuñez-Carrera

    2012-01-01

    Full Text Available The objective of this paper is the simulation and analysis of the BoilingWater Reactor (BWR lower head during a severe accident. The COUPLE computer code was used in this work to model the heatup of the reactor core material that slumps in the lower head of the reactor pressure vessel. The prediction of the lower head failure is an important issue in the severe accidents field, due to the accident progression and the radiological consequences that are completely different with or without the failure of the Reactor Pressure Vessel (RPV. The release of molten material to the primary containment and the possibility of steam explosion may produce the failure of the primary containment with high radiological consequences. Then, it is important to have a detailed model in order to predict the behavior of the reactor vessel lower head in a severe accident. In this paper, a hypothetical simulation of a Loss of Coolant Accident (LOCA with simultaneous loss of off-site power and without injection of cooling water is presented with the proposal to evaluate the temperature distribution and heatup of the lower part of the RPV. The SCDAPSIM/RELAP5 3.2 code was used to build the BWR model and conduct the numerical simulation.

  11. Examining Antecedents and Consequences of Tourist Satisfaction: A Structural Modeling Approach

    Institute of Scientific and Technical Information of China (English)

    WANG Xia; ZHANG Jie; GU Chaolin; ZHEN Feng

    2009-01-01

    While the importance of tourist satisfaction has been recognized by academic researchers for at least four decades, adequate tourist satisfaction models have not been developed or validated. This study presents a tourist satisfaction model for a destination and explores the antecedents (tourist expectations, destination image, perceived quality, and perceived value) and the consequences (tourist complaints and tourist loyalty) of tourist satisfaction using Guilin for the case study. Structural equation modeling results support the tourist satisfaction model of tourist expectations, destination image, perceived quality, and per-ceived value as four key antecedents of tourist satisfaction, with tourist satisfaction having a negative effect on tourist complaints and a positive effect on tourist loyalty. Managerial implications are drawn from the study findings and suggestions are given for future work.

  12. Professional shift-work drivers who adopt prophylactic naps can reduce the risk of car accidents during night work.

    Science.gov (United States)

    Garbarino, Sergio; Mascialino, Barbara; Penco, Maria Antonietta; Squarcia, Sandro; De Carli, Fabrizio; Nobili, Lino; Beelke, Manolo; Cuomo, Gianni; Ferrillo, Franco

    2004-11-01

    Night work can be dangerous because both circadian sleep propensity (process C) and sleep pressure due to the prolonged wakefulness (process S) contribute to the reduction of vigilance levels. As naps are a countermeasure to sleepiness, this study evaluates the role they play in preventing sleep-related accidents in Italian shift-working police drivers. The study concerns highway car accidents that occurred to Italian shift-working police drivers; it was performed in 2 steps: a retrospective analysis of the overall number of accidents that occurred during the years 1993--1997 (n, 1195), followed by a validation analysis of a smaller cohort of accidents prospectively collected during 2003 (n, 84). N/A. RETROSPECTIVE ANALYSIS: The influence of process S, process C, driver characteristics, and context conditions on accident risk, estimated by means of Cox hazard regression, revealed that nighttime accident risk was mainly influenced by process S levels. Consequently, an experimental mathematical model linking the hourly observed number of accidents to process S levels was designed. Its generalization to the theoretical case of drivers omitting naps showed an increase of about 38% of accidents. PROSPECTIVE ANALYSIS: In order to validate our results, we compared retrospective and prospective sleep patterns: no statistical difference was found. Again, the hourly number of accidents increased with homeostatic sleep pressure; the theoretical efficacy of napping was quantified in 48% accidents decrease. Our data seem to confirm that napping before working a night shift is an effective countermeasure to alertness and performance deterioration associated with night work. Moreover, this self-initiated behavior could have a prophylactic efficacy in reducing the number of car accidents.

  13. Testing the fitness consequences of the thermoregulatory and parental care models for the origin of endothermy.

    Directory of Open Access Journals (Sweden)

    Sabrina Clavijo-Baque

    Full Text Available The origin of endothermy is a puzzling phenomenon in the evolution of vertebrates. To address this issue several explicative models have been proposed. The main models proposed for the origin of endothermy are the aerobic capacity, the thermoregulatory and the parental care models. Our main proposal is that to compare the alternative models, a critical aspect is to determine how strongly natural selection was influenced by body temperature, and basal and maximum metabolic rates during the evolution of endothermy. We evaluate these relationships in the context of three main hypotheses aimed at explaining the evolution of endothermy, namely the parental care hypothesis and two hypotheses related to the thermoregulatory model (thermogenic capacity and higher body temperature models. We used data on basal and maximum metabolic rates and body temperature from 17 rodent populations, and used intrinsic population growth rate (R(max as a global proxy of fitness. We found greater support for the thermogenic capacity model of the thermoregulatory model. In other words, greater thermogenic capacity is associated with increased fitness in rodent populations. To our knowledge, this is the first test of the fitness consequences of the thermoregulatory and parental care models for the origin of endothermy.

  14. Quantifying the predictive consequences of model error with linear subspace analysis

    Science.gov (United States)

    White, Jeremy T.; Doherty, John E.; Hughes, Joseph D.

    2014-01-01

    All computer models are simplified and imperfect simulators of complex natural systems. The discrepancy arising from simplification induces bias in model predictions, which may be amplified by the process of model calibration. This paper presents a new method to identify and quantify the predictive consequences of calibrating a simplified computer model. The method is based on linear theory, and it scales efficiently to the large numbers of parameters and observations characteristic of groundwater and petroleum reservoir models. The method is applied to a range of predictions made with a synthetic integrated surface-water/groundwater model with thousands of parameters. Several different observation processing strategies and parameterization/regularization approaches are examined in detail, including use of the Karhunen-Loève parameter transformation. Predictive bias arising from model error is shown to be prediction specific and often invisible to the modeler. The amount of calibration-induced bias is influenced by several factors, including how expert knowledge is applied in the design of parameterization schemes, the number of parameters adjusted during calibration, how observations and model-generated counterparts are processed, and the level of fit with observations achieved through calibration. Failure to properly implement any of these factors in a prediction-specific manner may increase the potential for predictive bias in ways that are not visible to the calibration and uncertainty analysis process.

  15. Global risk of radioactive fallout after major nuclear reactor accidents

    Science.gov (United States)

    Lelieveld, J.; Kunkel, D.; Lawrence, M. G.

    2012-05-01

    Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7), using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  16. Global risk of radioactive fallout after major nuclear reactor accidents

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2012-05-01

    Full Text Available Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7, using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  17. Modeling of BWR core meltdown accidents - for application in the MELRPI. MOD2 computer code

    Energy Technology Data Exchange (ETDEWEB)

    Koh, B R; Kim, S H; Taleyarkhan, R P; Podowski, M Z; Lahey, Jr, R T

    1985-04-01

    This report summarizes improvements and modifications made in the MELRPI computer code. A major difference between this new, updated version of the code, called MELRPI.MOD2, and the one reported previously, concerns the inclusion of a model for the BWR emergency core cooling systems (ECCS). This model and its computer implementation, the ECCRPI subroutine, account for various emergency injection modes, for both intact and rubblized geometries. Other changes to MELRPI deal with an improved model for canister wall oxidation, rubble bed modeling, and numerical integration of system equations. A complete documentation of the entire MELRPI.MOD2 code is also given, including an input guide, list of subroutines, sample input/output and program listing.

  18. A Review of Accident Modelling Approaches for Complex Critical Sociotechnical Systems

    Science.gov (United States)

    2008-01-01

    integrated model has been demonstrated by analysing the failure in the Therac -25 sociotechnical system. THERAC -25 was an X-ray treatment machine...Baxter (2003) developed a three-layer model for the THERAC -25 system: the regulation authorities, the company who developed the system, and the...FailureFault Error FailureFault Error Failure THERAC -25 FAILURE DESIGN and CERTIFICATION Programmer Company Regulation Authorities Figure 7: Integrating

  19. Comparative Assessment of Severe Accidents in the Chinese Energy Sector

    Energy Technology Data Exchange (ETDEWEB)

    Hirschberg, S.; Burgherr, P.; Spiekerman, G.; Cazzoli, E.; Vitazek, J.; Cheng, L

    2003-03-01

    This report deals with the comparative assessment of accidents risks characteristic for the various electricity supply options. A reasonably complete picture of the wide spectrum of health, environmental and economic effects associated with various energy systems can only be obtained by considering damages due to normal operation as well as due to accidents. The focus of the present work is on severe accidents, as these are considered controversial. By severe accidents we understand potential or actual accidents that represent a significant risk to people, property and the environment and may lead to large consequences. (author)

  20. Accident knowledge and emergency management

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, B.; Groenberg, C.D.

    1997-03-01

    The report contains an overall frame for transformation of knowledge and experience from risk analysis to emergency education. An accident model has been developed to describe the emergency situation. A key concept of this model is uncontrolled flow of energy (UFOE), essential elements are the state, location and movement of the energy (and mass). A UFOE can be considered as the driving force of an accident, e.g., an explosion, a fire, a release of heavy gases. As long as the energy is confined, i.e. the location and movement of the energy are under control, the situation is safe, but loss of confinement will create a hazardous situation that may develop into an accident. A domain model has been developed for representing accident and emergency scenarios occurring in society. The domain model uses three main categories: status, context and objectives. A domain is a group of activities with allied goals and elements and ten specific domains have been investigated: process plant, storage, nuclear power plant, energy distribution, marine transport of goods, marine transport of people, aviation, transport by road, transport by rail and natural disasters. Totally 25 accident cases were consulted and information was extracted for filling into the schematic representations with two to four cases pr. specific domain. (au) 41 tabs., 8 ills.; 79 refs.

  1. A model for the release, dispersion and environmental impact of a postulated reactor accident from a submerged commercial nuclear power plant

    Science.gov (United States)

    Bertch, Timothy Creston

    1998-12-01

    Nuclear power plants are inherently suitable for submerged applications and could provide power to the shore power grid or support future underwater applications. The technology exists today and the construction of a submerged commercial nuclear power plant may become desirable. A submerged reactor is safer to humans because the infinite supply of water for heat removal, particulate retention in the water column, sedimentation to the ocean floor and inherent shielding of the aquatic environment would significantly mitigate the effects of a reactor accident. A better understanding of reactor operation in this new environment is required to quantify the radioecological impact and to determine the suitability of this concept. The impact of release to the environment from a severe reactor accident is a new aspect of the field of marine radioecology. Current efforts have been centered on radioecological impacts of nuclear waste disposal, nuclear weapons testing fallout and shore nuclear plant discharges. This dissertation examines the environmental impact of a severe reactor accident in a submerged commercial nuclear power plant, modeling a postulated site on the Atlantic continental shelf adjacent to the United States. This effort models the effects of geography, decay, particle transport/dispersion, bioaccumulation and elimination with associated dose commitment. The use of a source term equivalent to the release from Chernobyl allows comparison between the impacts of that accident and the postulated submerged commercial reactor plant accident. All input parameters are evaluated using sensitivity analysis. The effect of the release on marine biota is determined. Study of the pathways to humans from gaseous radionuclides, consumption of contaminated marine biota and direct exposure as contaminated water reaches the shoreline is conducted. The model developed by this effort predicts a significant mitigation of the radioecological impact of the reactor accident release

  2. Emulation and Sobol' sensitivity analysis of an atmospheric dispersion model applied to the Fukushima nuclear accident

    Science.gov (United States)

    Girard, Sylvain; Mallet, Vivien; Korsakissok, Irène; Mathieu, Anne

    2016-04-01

    Simulations of the atmospheric dispersion of radionuclides involve large uncertainties originating from the limited knowledge of meteorological input data, composition, amount and timing of emissions, and some model parameters. The estimation of these uncertainties is an essential complement to modeling for decision making in case of an accidental release. We have studied the relative influence of a set of uncertain inputs on several outputs from the Eulerian model Polyphemus/Polair3D on the Fukushima case. We chose to use the variance-based sensitivity analysis method of Sobol'. This method requires a large number of model evaluations which was not achievable directly due to the high computational cost of Polyphemus/Polair3D. To circumvent this issue, we built a mathematical approximation of the model using Gaussian process emulation. We observed that aggregated outputs are mainly driven by the amount of emitted radionuclides, while local outputs are mostly sensitive to wind perturbations. The release height is notably influential, but only in the vicinity of the source. Finally, averaging either spatially or temporally tends to cancel out interactions between uncertain inputs.

  3. Escalation scenarios initiated by gas explosions on offshore installations. Probabilistic cause and consequence modelling

    Energy Technology Data Exchange (ETDEWEB)

    Eknes, Monika Loeland

    1996-12-31

    This Dr. ing. thesis deals with escalation scenarios initiated by gas explosions on offshore installations. Gas explosions is one of the major hazards to such installations. The objectives were to estimate the probability of ignition and frequency of gas explosions for gas leaks on top sides of offshore installations, and to estimate the response and resistance of components that could result in escalation if they failed. Main fields considered cover risk analysis methodology, gas explosions, simplified escalation models, evaluation of structural consequences, case studies, and guidelines. 107 refs., 33 figs., 33 tabs.

  4. LADTAP-PROB: A PROBABILISTIC MODEL TO ASSESS RADIOLOGICAL CONSEQUENCES FROM LIQUID RADIOACTIVE RELEASES

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E; Trevor Foley, T; Tim Jannik, T

    2009-01-26

    The potential radiological consequences to humans resulting from aqueous releases at the Savannah River Site (SRS) have usually been assessed using the computer code LADTAP or deterministic variations of this code. The advancement of LADTAP over the years included LADTAP II (a computer program that still resides on the mainframe at SRS) [1], LADTAP XL{copyright} (Microsoft Excel{reg_sign} Spreadsheet) [2], and other versions specific to SRS areas such as [3]. The spreadsheet variations of LADTAP contain two worksheets: LADTAP and IRRIDOSE. The LADTAP worksheet estimates dose for environmental pathways including ingestion of water and fish and external exposure resulting from recreational activities. IRRIDOSE estimates potential dose to individuals from irrigation of food crops with contaminated water. A new version of this deterministic methodology, LADTAP-PROB, was developed at Savannah River National Laboratory (SRNL) to (1) consider the complete range of the model parameter values (not just maximum or mean values), (2) determine the influences of parameter uncertainties within the LADTAP methodology, to perform a sensitivity analysis of all model parameters (to identify the input parameters to which model results are most sensitive), and (3) probabilistically assess radiological consequences from contaminated water. This study presents the methodology applied in LADTAP-PROB.

  5. A review of {sup 137}Cs transfer to fungi and consequences for modelling environmental transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gillett, A.G. E-mail: andy.gillett@nottingham.ac.uk; Crout, N.M.J

    2000-03-01

    A review of the published literature describing {sup 137}Cs transfer to fungi was carried out, summarising the collated data to determine factors controlling transfer and identify an appropriate modelling approach to predict future contamination. {sup 137}Cs transfer ratios (TR) are derived for fungi species collected within Europe and the CIS. Considerable variability in TRs is demonstrated, with TRs varying between <0.001 and >10 m{sup 2} kg{sup -1} across all species and over three orders of magnitude for individual species (e.g. Boletus badius). Generally, meta-information (such as habitat and soil attributes) is poorly reported in the literature so that classification of the TR is limited to the effect of nutritional type (P<0.025) in the order mycorrhizal>saprophytic{approx}parasitic. Analysis of the literature data set (a heterogeneous source) suggests that there is no statistical evidence to indicate a decrease in TRs for 10 years after the Chernobyl accident. Spatial analysis of a data set for Belgium indicates variability in {sup 137}Cs transfer within a sampling location, such that fruitbodies collected over a scale of approximately 5 km would show activities as variable as those collected over a much larger scale ({approx} or>50 km). Therefore, it is proposed that the collated data sets for individual species can be used to derive 'best estimates' for the parameters describing the distribution of TRs. These can then be used to estimate an 'effective' TR, which, when combined with local soil deposition level and frequency and effect of culinary practices, can give an estimate of the activity of fungi consumed by the general population.

  6. Modeling a Civil Event Case Study for Consequence Management Using the IMPRINT Forces Module

    Science.gov (United States)

    Gacy, Marc; Gosakan, Mala; Eckdahl, Angela; Miller, Jeffrey R.

    2012-01-01

    A critical challenge in the Consequence Management (CM) domain is the appropriate allocation of necessary and skilled military and civilian personnel and materiel resources in unexpected emergencies. To aid this process we used the Forces module in the Improved Performance Research Integration Tool (IMPRINT). This module enables analysts to enter personnel and equipment capabilities, prioritized schedules and numbers available, along with unexpected emergency requirements in order to assess force response requirements. Using a suspected terrorist threat on a college campus, we developed a test case model which exercised the capabilities of the module, including the scope and scale of operations. The model incorporates data from multiple sources, including daily schedules and frequency of events such as fire calls. Our preliminary results indicate that the model can predict potential decreases in civilian emergency response coverage due to an involved unplanned incident requiring significant portions of police, fire and civil responses teams.

  7. World Meteorological Organization's model simulations of the radionuclide dispersion and deposition from the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Draxler, Roland; Arnold, Dèlia; Chino, Masamichi; Galmarini, Stefano; Hort, Matthew; Jones, Andrew; Leadbetter, Susan; Malo, Alain; Maurer, Christian; Rolph, Glenn; Saito, Kazuo; Servranckx, René; Shimbori, Toshiki; Solazzo, Efisio; Wotawa, Gerhard

    2015-01-01

    Five different atmospheric transport and dispersion model's (ATDM) deposition and air concentration results for atmospheric releases from the Fukushima Daiichi nuclear power plant accident were evaluated over Japan using regional (137)Cs deposition measurements and (137)Cs and (131)I air concentration time series at one location about 110 km from the plant. Some of the ATDMs used the same and others different meteorological data consistent with their normal operating practices. There were four global meteorological analyses data sets available and two regional high-resolution analyses. Not all of the ATDMs were able to use all of the meteorological data combinations. The ATDMs were configured identically as much as possible with respect to the release duration, release height, concentration grid size, and averaging time. However, each ATDM retained its unique treatment of the vertical velocity field and the wet and dry deposition, one of the largest uncertainties in these calculations. There were 18 ATDM-meteorology combinations available for evaluation. The deposition results showed that even when using the same meteorological analysis, each ATDM can produce quite different deposition patterns. The better calculations in terms of both deposition and air concentration were associated with the smoother ATDM deposition patterns. The best model with respect to the deposition was not always the best model with respect to air concentrations. The use of high-resolution mesoscale analyses improved ATDM performance; however, high-resolution precipitation analyses did not improve ATDM predictions. Although some ATDMs could be identified as better performers for either deposition or air concentration calculations, overall, the ensemble mean of a subset of better performing members provided more consistent results for both types of calculations.

  8. A model for the analysis of loss of decay heat removal during loss of coolant accident in MTR pool type research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bousbia-salah, Anis [Dipartimento di Ingegneria Meccanica, Nucleari e della Produzione, Facolta di Ingegneria, Universita di Pisa, Via Diotisalvi, 2, 56126 Pisa (Italy)]. E-mail: b.salah@ing.unipi.it; Meftah, Brahim [Division Reacteur - Centre de Recherche Nucleaire Draria (CRND), BP 43 Sebala DRARIA - Algiers (Algeria); Hamidouche, Tewfik [Laboratoire des Analyses de Surete, Centre de Recherche Nucleaire d' Alger (CRNA), 02 Boulevard Frantz Fanon, B.P. 399, 16000 Algiers (Algeria)]. E-mail: thamidouche@comena-dz.org; Si-Ahmed, El Khider [Laboratoire des Ecoulements Polyhpasiques, Universite des Sciences et de la Technologie d' Alger, Algiers (Algeria)

    2006-03-15

    During a loss of coolant accident leading to total emptying of the reactor pool, the decay heat could be removed through air natural convection. However, under partial pool emptying the core is partially submerged and the coolant circulation inside the fuel element could no more be possible. Under such conditions, a core overheat takes place, and the thermal energy is essentially diffused from the core to its periphery by combined thermal radiation and conduction. In order to predict fuel element temperature evolution under such conditions a mathematical model is performed. The model is based on a 3D geometry and takes into account a variety of core configurations including fuel elements (standard and control), reflector elements and grid plates. The homogeneous flow model is used and the fluid conservation equations are solved using a semi-implicit finite difference method. Preliminary tests of the developed model were made by considering a series of hypothetical accidents. In the current framework a loss of decay heat removal accidents in the IAEA benchmark open pool MTR-type research reactor is considered. It is shown that in the case of a low core immersion height no water boiling is observed and the fuel surface temperature rise remains below the melting point of the aluminium cladding.

  9. A RISK MEASUREMENT AND MANAGEMENT MODEL FOR PREVENTING UNMANNED AIR VEHICLE ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Hüdayim BAŞAK

    2008-01-01

    Full Text Available In this study, it is aimed to investigate operationally risky areas by analyzing dangers which can arise during the maintenance and flight activities of Unmanned Air Vehicles (UAVs. For this purpose, a risk analysis methodology was introduced and then within the framework of the application, a sample of risk management model was developed. During the development of the model, personal experiences in the area of UAVs were benefited and a risk management technique consisting of five steps used by pioneering international aviation companies in fliht safety was utilized.

  10. Consequences of radioactive releases into the sea resulting from the accident at the Fukushima Dai-ichi nuclear power plant - Evolution of expert investigation according to the data available

    OpenAIRE

    2012-01-01

    The accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) in March 2011 led to an unprecedented direct input of artificial radioactivity into the marine environment. The Institute for Radioprotection and Nuclear Safety was requested by the French authorities to investigate the radioecological impact of this input, in particular the potential contamination of products of marine origin used for human consumption. This article describes the close link between the responses provided and ...

  11. An evaluation of spindle-shaft seizure accident sequences for the Schenck Dynamic Balancer

    Energy Technology Data Exchange (ETDEWEB)

    Bott, T.F.; Fischer, S.R.

    1998-11-01

    This study was conducted at the request of the USDOE/AL Dynamic Balancer Project Team to develop a set of representative accident sequences initiated by rapid seizure of the spindle shaft of the Schenck dynamic balancing machine used in the mass properties testing activities in Bay 12-60 at the Pantex Plant. This Balancer is used for balancing reentry vehicles. In addition, the study identified potential causes of possible spindle-shaft seizure leading to a rapid deceleration of the rotating assembly. These accident sequences extend to the point that the reentry vehicle either remains in stable condition on the balancing machine or leaves the machine with some translational and rotational motion. Fault-tree analysis was used to identify possible causes of spindle-shaft seizure, and failure modes and effects analysis identified the results of shearing of different machine components. Cause-consequence diagrams were used to help develop accident sequences resulting from the possible effects of spindle-shaft seizure. To make these accident sequences physically reasonable, the analysts used idealized models of the dynamics of rotating masses. Idealized physical modeling also was used to provide approximate values of accident parameters that lead to branching down different accident progression paths. The exacerbating conditions of balancing machine over-speed and improper assembly of the fixture to the face plate are also addressed.

  12. An evaluation of spindle-shaft seizure accident sequences for the Schenck Dynamic Balancer

    Energy Technology Data Exchange (ETDEWEB)

    Bott, T.F.; Fischer, S.R.

    1998-11-01

    This study was conducted at the request of the USDOE/AL Dynamic Balancer Project Team to develop a set of representative accident sequences initiated by rapid seizure of the spindle shaft of the Schenck dynamic balancing machine used in the mass properties testing activities in Bay 12-60 at the Pantex Plant. This Balancer is used for balancing reentry vehicles. In addition, the study identified potential causes of possible spindle-shaft seizure leading to a rapid deceleration of the rotating assembly. These accident sequences extend to the point that the reentry vehicle either remains in stable condition on the balancing machine or leaves the machine with some translational and rotational motion. Fault-tree analysis was used to identify possible causes of spindle-shaft seizure, and failure modes and effects analysis identified the results of shearing of different machine components. Cause-consequence diagrams were used to help develop accident sequences resulting from the possible effects of spindle-shaft seizure. To make these accident sequences physically reasonable, the analysts used idealized models of the dynamics of rotating masses. Idealized physical modeling also was used to provide approximate values of accident parameters that lead to branching down different accident progression paths. The exacerbating conditions of balancing machine over-speed and improper assembly of the fixture to the face plate are also addressed.

  13. Perception model supports the analysis of vestibular illusions in flight accidents

    NARCIS (Netherlands)

    Groen, E.L.; Houben, M.M.J.; Bos, J.E.; Mumaw, R.J.

    2016-01-01

    TNO and Boeing developed a “Spatial Disorientation Identification Tool” (SDiT) to support the investigation of recorded aircraft motion for its potential to induce Spatial Disorientation (SD). The tool is based on a perception model that consists of transfer functions representing the dynamics in

  14. Development of Methodology for Spent Fuel Pool Severe Accident Analysis Using MELCOR Program

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Tae; Shin, Jae-Uk [RETech. Co. LTD., Yongin (Korea, Republic of); Ahn, Kwang-Il [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The general reason why SFP severe accident analysis has to be considered is that there is a potential great risk due to the huge number of fuel assemblies and no containment in a SFP building. In most cases, the SFP building is vulnerable to external damage or attack. In contrary, low decay heat of fuel assemblies may make the accident processes slow compared to the accident in reactor core because of a great deal of water. In short, its severity of consequence cannot exclude the consideration of SFP risk management. The U.S. Nuclear Regulatory Commission has performed the consequence studies of postulated spent fuel pool accident. The Fukushima-Daiichi accident has accelerated the needs for the consequence studies of postulated spent fuel pool accidents, causing the nuclear industry and regulatory bodies to reexamine several assumptions concerning beyond-design basis events such as a station blackout. The tsunami brought about the loss of coolant accident, leading to the explosion of hydrogen in the SFP building. Analyses of SFP accident processes in the case of a loss of coolant with no heat removal have studied. Few studies however have focused on a long term process of SFP severe accident under no mitigation action such as a water makeup to SFP. USNRC and OECD have co-worked to examine the behavior of PWR fuel assemblies under severe accident conditions in a spent fuel rack. In support of the investigation, several new features of MELCOR model have been added to simulate both BWR fuel assembly and PWR 17 x 17 assembly in a spent fuel pool rack undergoing severe accident conditions. The purpose of the study in this paper is to develop a methodology of the long-term analysis for the plant level SFP severe accident by using the new-featured MELCOR program in the OPR-1000 Nuclear Power Plant. The study is to investigate the ability of MELCOR in predicting an entire process of SFP severe accident phenomena including the molten corium and concrete reaction. The

  15. 气象因素对电力安全事故影响的模型%Research on Impact Model of Meteorological Factors on the Power Accidents

    Institute of Scientific and Technical Information of China (English)

    李彦斌; 韩颖; 张嵘; 李彦国

    2013-01-01

      以我国南方某地区为例,收集了该地区连续48个月的电力事故数据及其对应的15个气象要素资料。首先用因子分析法消除了15个气象要素的多重共线性,提取了温度因子、降水因子、湿度因子、风力因子4类主要因素,其次应用Logistic回归建立了气象因素对电力事故的影响模型。模型探究了气象条件与电力事故的内在联系,并用2010年的检验样本验证了模型拟合的准确性,为电力事故预警机制的建立进行了积极的探讨。%Taking a certain region in South China for example, the power system accident data in continuous 48 months of this region and corresponding data of 15 meteorological factors are collected. Firstly, the multicollinearity of the 15 meteorological factors are eliminated by factor analysis, and four kinds of main factors such as temperature factor, precipitation factor, humidity factor and wind power factor are extracted;secondly, an impact model of meteorological factors on power system accidents is established by Logistic regression. Using the established impact model the internal relations between meteorological conditions and power system accidents are explored, and the fitting accuracy of the proposed model is validated by test samples in 2010. The proposed impact model is available for reference to the establishment of early warning mechanism for power system accidents.

  16. Statistical Surrogate Models for Estimating Probability of High-Consequence Climate Change

    Science.gov (United States)

    Field, R.; Constantine, P.; Boslough, M.

    2011-12-01

    We have posed the climate change problem in a framework similar to that used in safety engineering, by acknowledging that probabilistic risk assessments focused on low-probability, high-consequence climate events are perhaps more appropriate than studies focused simply on best estimates. To properly explore the tails of the distribution requires extensive sampling, which is not possible with existing coupled atmospheric models due to the high computational cost of each simulation. We have developed specialized statistical surrogate models (SSMs) that can be used to make predictions about the tails of the associated probability distributions. A SSM is different than a deterministic surrogate model in that it represents each climate variable of interest as a space/time random field, that is, a random variable for every fixed location in the atmosphere at all times. The SSM can be calibrated to available spatial and temporal data from existing climate databases, or to a collection of outputs from general circulation models. Because of its reduced size and complexity, the realization of a large number of independent model outputs from a SSM becomes computationally straightforward, so that quantifying the risk associated with low-probability, high-consequence climate events becomes feasible. A Bayesian framework was also developed to provide quantitative measures of confidence, via Bayesian credible intervals, to assess these risks. To illustrate the use of the SSM, we considered two collections of NCAR CCSM 3.0 output data. The first collection corresponds to average December surface temperature for years 1990-1999 based on a collection of 8 different model runs obtained from the Program for Climate Model Diagnosis and Intercomparison (PCMDI). We calibrated the surrogate model to the available model data and make various point predictions. We also analyzed average precipitation rate in June, July, and August over a 54-year period assuming a cyclic Y2K ocean model. We

  17. An improved version of the consequence analysis model for chemical emergencies, ESCAPE

    Science.gov (United States)

    Kukkonen, J.; Nikmo, J.; Riikonen, K.

    2017-02-01

    We present a refined version of a mathematical model called ESCAPE, "Expert System for Consequence Analysis and Preparing for Emergencies". The model has been designed for evaluating the releases of toxic and flammable gases into the atmosphere, their atmospheric dispersion and the effects on humans and the environment. We describe (i) the mathematical treatments of this model, (ii) a verification and evaluation of the model against selected experimental field data, and (iii) a new operational implementation of the model. The new mathematical treatments include state-of-the-art atmospheric vertical profiles and new submodels for dense gas and passive atmospheric dispersion. The model performance was first successfully verified using the data of the Thorney Island campaign, and then evaluated against the Desert Tortoise campaign. For the latter campaign, the geometric mean bias was 1.72 (this corresponds to an underprediction of approximately 70%) and 0.71 (overprediction of approximately 30%) for the concentration and the plume half-width, respectively. The geometric variance was computers, tablets and mobile phones. The predicted results can be post-processed using geographic information systems. The model has already proved to be a useful tool of assessment for the needs of emergency response authorities in contingency planning.

  18. A cross-scale numerical modeling system for management support of oil spill accidents.

    Science.gov (United States)

    Azevedo, Alberto; Oliveira, Anabela; Fortunato, André B; Zhang, Joseph; Baptista, António M

    2014-03-15

    A flexible 2D/3D oil spill modeling system addressing the distinct nature of the surface and water column fluids, major oil weathering and improved retention/reposition processes in coastal zones is presented. The system integrates hydrodynamic, transport and oil weathering modules, which can be combined to offer different-complexity descriptions as required by applications across the river-to-ocean continuum. Features include accounting for different composition and reology in the surface and water column mixtures, as well as spreading, evaporation, water-in-oil emulsification, shoreline retention, dispersion and dissolution. The use of unstructured grids provides flexibility and efficiency in handling spills in complex geometries and across scales. The use of high-order Eulerian-Lagrangian methods allows for computational efficiency and for handling key processes in ways consistent with their distinct mathematical nature and time scales. The modeling system is tested through a suite of synthetic, laboratory and realistic-domain benchmarks, which demonstrate robust handling of key processes and of 2D/3D couplings. The application of the modeling system to a spill scenario at the entrance of a port in a coastal lagoon illustrates the power of the approach to represent spills that occur in coastal regions with complex boundaries and bathymetry.

  19. Modeling of Radionuclides from the Fukushima Dai-ichi Nuclear Accident to Korea

    Science.gov (United States)

    Lee, K.; Yun, J. Y.

    2016-12-01

    FLEXPART Lagrangian model and NCEP/GFS meteorological data were employed and transport of radionuclides from Fukushima Dai-ichi nuclear plant toward Korean Peninsula was simulated for three key artificial radionuclides (Cs-137, I-131, and Xe-133). By simulating horizontal distributions and tracking the trajectories of the radionuclides for the period of 10 March 2011 to 20 April 2011, the following three distinctive different arrival pathways were detected; 1) intercontinental scale - plume released since mid-March 2011 and transported to the North to arrive Korea on 23 March 2011, 2) global(hemispherical) scale - plume traveling over the whole northern hemisphere passing through the Pacific Ocean/Europe to reach the Korean Peninsula with relatively low concentrations in late March 2011 and, 3) regional scale - plume released on early April 2011 arrived at the Korean Peninsula via southwest sea of Japan influenced directly by veering mesoscale wind circulations. Our identification of these transport routes at three different scales of meteorological circulations suggests the feasibility of a multi-scale approach for more accurate prediction of radionuclide transport in the study area. In light of the fact that the observed arrival/duration time of peaks were explained well by the FLEXPART model coupled with NCEP/GFS input data, our approach can be used meaningfully as a decision support model for radiation emergency situations

  20. Risk-based modeling of early warning systems for pollution accidents.

    Science.gov (United States)

    Grayman, W M; Males, R M

    2002-01-01

    An early warning system is a mechanism for detecting, characterizing and providing notification of a source water contamination event (spill event) in order to mitigate the impact of contamination. Spill events are highly probabilistic occurrences with major spills, which can have very significant impacts on raw water sources of drinking water, being relatively rare. A systematic method for designing and operating early warning systems that considers the highly variable, probabilistic nature of many aspects of the system is described. The methodology accounts for the probability of spills, behavior of monitoring equipment, variable hydrology, and the probability of obtaining information about spills independent of a monitoring system. Spill Risk, a risk-based model using Monte Carlo simulation techniques has been developed and its utility has been demonstrated as part of an AWWA Research Foundation sponsored project. The model has been applied to several hypothetical river situations and to an actual section of the Ohio River. Additionally, the model has been systematically applied to a wide range of conditions in order to develop general guidance on design of early warning systems.

  1. Radioactive materials transport accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    McSweeney, T.I.; Maheras, S.J.; Ross, S.B. [Battelle Memorial Inst. (United States)

    2004-07-01

    Over the last 25 years, one of the major issues raised regarding radioactive material transportation has been the risk of severe accidents. While numerous studies have shown that traffic fatalities dominate the risk, modeling the risk of severe accidents has remained one of the most difficult analysis problems. This paper will show how models that were developed for nuclear spent fuel transport accident analysis can be adopted to obtain estimates of release fractions for other types of radioactive material such as vitrified highlevel radioactive waste. The paper will also show how some experimental results from fire experiments involving low level waste packaging can be used in modeling transport accident analysis with this waste form. The results of the analysis enable an analyst to clearly show the differences in the release fractions as a function of accident severity. The paper will also show that by placing the data in a database such as ACCESS trademark, it is possible to obtain risk measures for transporting the waste forms along proposed routes from the generator site to potential final disposal sites.

  2. Modeling vulnerability to thermokarst disturbance and its consequences on regional land cover dynamic in boreal Alaska

    Science.gov (United States)

    Genet, H.; Lara, M. J.; Bolton, W. R.; McGuire, A. D.

    2016-12-01

    Estimation of the magnitude and consequences of permafrost degradation in high latitude is one of the most urgent research challenges related to contemporary and future climate change. In addition to widespread vertical degradation, ice-rich permafrost can thaw laterally, often triggering abrupt subsidence of the ground surface called thermokart. In this depression, permafrost plateau vegetation will transition to wetlands or lakes, while surface water of the surrounding landscape may drain towards it. These abrupt changes in land cover and hydrology can have dramatic consequences from wildlife habitat and biogeochemical cycles. Although recent studies have documented an acceleration of the rates of thermokarst formation in boreal and arctic peatlands, the importance of thermokarst at the regional level is still poorly understood. To better understand the vulnerability of the landscape to thermokarst disturbance in Alaska, we developed the Alaska Thermokarst Model (ATM), a state-and-transition model designed to simulate land cover change associated with thermokarst disturbance. In boreal regions, the model simulates transitions from permafrost plateau forest to thermokarst lake, bog or fen, as a function of climate and fire dynamics, permafrost characteristics and physiographic information. This model is designed and parameterized based on existing literature and a new repeated imagery analysis we conducted in a major wetland complex in boreal Alaska. We will present simulation and validation of thermokarst dynamic and associated land cover change in two wetland complexes in boreal Alaska, from 2000 to 2100 for six climate scenarios associating three AR5 emission scenarios and two global circulation model simulations. By 2100, ATM is predicting decrease between 3.5 and 9.1 % in the extent of permafrost plateau forest, mostly to the benefit of thermokarst fen, and lake. This analysis allowed us to assess the importance of thermokarst dynamics and landscape evolution

  3. Study on Nuclear Accident Precursors Using AHP and BBN

    Directory of Open Access Journals (Sweden)

    Sujin Park

    2014-01-01

    Full Text Available Most of the nuclear accident reports used to indicate the implicit precursors which are not easily quantified as underlying factors. The current Probabilistic Safety Assessment (PSA is capable of quantifying the importance of accident causes in limited scope. It was, therefore, difficult to achieve quantifiable decision-making for resource allocation. In this study, the methodology which facilitates quantifying these precursors and a case study were presented. First, four implicit precursors have been obtained by evaluating the causality and hierarchy structure of various accident factors. Eventually, it turned out that they represent the lack of knowledge. After four precursors are selected, subprecursors were investigated and their cause-consequence relationship was implemented by Bayesian Belief Network (BBN. To prioritize the precursors, the prior probability is initially estimated by expert judgment and updated upon observations. The pair-wise importance between precursors is calculated by Analytic Hierarchy Process (AHP and the results are converted into node probability tables of the BBN model. Using this method, the sensitivity and the posterior probability of each precursor can be analyzed so that it enables making prioritization for the factors. We tried to prioritize the lessons learned from Fukushima accident to demonstrate the feasibility of the proposed methodology.

  4. [Antecedents and consequences of workplace bullying: a longitudinal analysis with a structural equation model].

    Science.gov (United States)

    Carretero Domínguez, Noelia; Gil-Monte, Pedro Rafael; Luciano Devis, Juan Vicente

    2011-11-01

    Most studies focusing on the antecedents and consequences of workplace bullying have used a cross-sectional design, which impedes determining the causality of the relationships. In the present work, we analyzed, by means of structural equation models, the relationship between workplace bullying and some variables that are considered antecedents (interpersonal conflicts, role ambiguity, role conflict, and workplace social support) or consequences (health complaints and inclination to absenteeism from work) of this phenomenon. Multicenter study with two phases. The sample consisted of 696 employees from 66 centers. Workplace bullying was assessed by means of the "Mobbing-UNIPSICO" questionnaire, and the other variables with frequency scales. The cross-sectional models indicated a significant association between role conflict, workplace social support, and workplace bullying in both study periods. Concerning the longitudinal relationships, only workplace social support was a significant predictor of workplace bullying, which, in turn, was a cross-sectional and longitudinal predictor of workers' health complaints. Our results show the mediating effect of workplace bullying between certain work conditions and health complaints, and it is recommendable to replicate these findings in a multi-occupational sample.

  5. Blume-Emery-Griffiths model on three-dimensional lattices: Consequences for the antiferromagnetic Potts model

    Science.gov (United States)

    Lapinskas, Saulius; Rosengren, Anders

    1994-06-01

    Using the cluster-variation method we study the phase diagram of the Blume-Emergy-Griffiths (BEG) model on simple cubic and face-centered cubic lattices. For the simple cubic lattice the main attention is paid to reentrant phenomena and ferrimagnetic phases occurring in a certain range of coupling constants. The results are in close agreement with Monte-Carlo data, available for parts of the phase diagram. Several ferrimagnetic phases are obtained in the vicinity of the line in parameter space, at which the model reduces to the antiferromagnetic three-state Potts model. Our results imply the existence of three phase transitions in the antiferromagnetic Potts model on the simple-cubic lattice. The phase diagrams for the BEG model on the face-centered cubic lattice are obtained in the region of antiquadrupolar ordering. Also the several ordered phases of the antiferromagnetic Potts model on this lattice are discussed.

  6. Systematics of Reconstructed Process Facility Criticality Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.L.; McLaughlin, T.P.; Monahan, S.P.

    1999-09-19

    The systematics of the characteristics of twenty-one criticality accidents occurring in nuclear processing facilities of the Russian Federation, the United States, and the United Kingdom are examined. By systematics the authors mean the degree of consistency or agreement between the factual parameters reported for the accidents and the experimentally known conditions for criticality. The twenty-one reported process criticality accidents are not sufficiently well described to justify attempting detailed neutronic modeling. However, results of classic hand calculations confirm the credibility of the reported accident conditions.

  7. Modeling the Geographic Consequence and Pattern of Dengue Fever Transmission in Thailand.

    Science.gov (United States)

    Bekoe, Collins; Pansombut, Tatdow; Riyapan, Pakwan; Kakchapati, Sampurna; Phon-On, Aniruth

    2017-05-04

    Dengue fever is one of the infectious diseases that is still a public health problem in Thailand. This study considers in detail, the geographic consequence, seasonal and pattern of dengue fever transmission among the 76 provinces of Thailand from 2003 to 2015. A cross-sectional study. The data for the study was from the Department of Disease Control under the Bureau of Epidemiology, Thailand. The quarterly effects and location on the transmission of dengue was modeled using an alternative additive log-linear model. The model fitted well as illustrated by the residual plots and the  Again, the model showed that dengue fever is high in the second quarter of every year from May to August. There was an evidence of an increase in the trend of dengue annually from 2003 to 2015. There was a difference in the distribution of dengue fever within and between provinces. The areas of high risks were the central and southern regions of Thailand. The log-linear model provided a simple medium of modeling dengue fever transmission. The results are very important in the geographic distribution of dengue fever patterns.

  8. Limitations of empirical sediment transport formulas for shallow water and their consequences for swash zone modelling

    CERN Document Server

    Li, Wei; Pähtz, Thomas; He, Zhiguo; Cao, Zhixian

    2016-01-01

    Volumetric sediment concentrations computed by phase-resolving swash morphodynamic models are shown to exceed unity minus porosity (i.e. the maximal physically possible concentration value) by up to factor of $10^5$ when using standard expressions to compute the sediment transport rate. An ad hoc limit of sediment concentration is introduced as a means to evaluate consequences of exceeding physically realistic concentration by standard expressions. We find that implementation of this ad hoc limit strongly changes the quantitative and qualitative predictions of phase-resolving swash morphodynamic models, suggesting that existing swash predictions are unreliable. This is because standard expressions inappropriately consider or ignore the fact that the shallow swash water depth limits the storage capacity of transported sediment.

  9. Global and local cancer risks after the Fukushima Nuclear Power Plant accident as seen from Chernobyl: a modeling study for radiocaesium ((134)Cs &(137)Cs).

    Science.gov (United States)

    Evangeliou, Nikolaos; Balkanski, Yves; Cozic, Anne; Møller, Anders Pape

    2014-03-01

    The accident at the Fukushima Daiichi Nuclear Power Plant (NPP) in Japan resulted in the release of a large number of fission products that were transported worldwide. We study the effects of two of the most dangerous radionuclides emitted, (137)Cs (half-life: 30.2years) and (134)Cs (half-life: 2.06years), which were transported across the world constituting the global fallout (together with iodine isotopes and noble gasses) after nuclear releases. The main purpose is to provide preliminary cancer risk estimates after the Fukushima NPP accident, in terms of excess lifetime incident and death risks, prior to epidemiology, and compare them with those occurred after the Chernobyl accident. Moreover, cancer risks are presented for the local population in the form of high-resolution risk maps for 3 population classes and for both sexes. The atmospheric transport model LMDZORINCA was used to simulate the global dispersion of radiocaesium after the accident. Air and ground activity concentrations have been incorporated with monitoring data as input to the LNT-model (Linear Non-Threshold) frequently used in risk assessments of all solid cancers. Cancer risks were estimated to be small for the global population in regions outside Japan. Women are more sensitive to radiation than men, although the largest risks were recorded for infants; the risk is not depended on the sex at the age-at-exposure. Radiation risks from Fukushima were more enhanced near the plant, while the evacuation measures were crucial for its reduction. According to our estimations, 730-1700 excess cancer incidents are expected of which around 65% may be fatal, which are very close to what has been already published (see references therein). Finally, we applied the same calculations using the DDREF (Dose and Dose Rate Effectiveness Factor), which is recommended by the ICRP, UNSCEAR and EPA as an alternative reduction factor instead of using a threshold value (which is still unknown). Excess lifetime cancer

  10. Systematic approach for assessment of accident risks in chemical and nuclear processing; Abordagem sistematica para avaliacao de riscos de acidentes em instalacoes de processamento quimico e nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Senne Junior, Murillo

    2003-07-15

    The industrial accidents which occurred in the last years, particularly in the 80's, contributed a significant way to draw the attention of the government, industry and the society as a whole to the mechanisms for preventing events that could affect people's safety and the environment quality. Techniques and methods extensively used the nuclear, aeronautic and war industries so far were adapted to performing analysis and evaluation of the risks associated to other industrial activities, especially in the petroleum, chemistry and petrochemical areas. The risk analysis in industrial facilities is carried out through the evaluation of the probability or frequency of the accidents and their consequences. However, no systematized methodology that could supply the tools for identifying possible accidents likely to take place in an installation is available in the literature. Neither existing are methodologies for the identification of the models for evaluation of the accidents' consequences nor for the selection of the available techniques for qualitative or quantitative analysis of the possibility of occurrence of the accident being focused. The objective of this work is to develop and implement a methodology for identification of the risks of accidents in chemical and nuclear processing facilities as well as for the evaluation of their consequences on persons. For the development of the methodology, the main possible accidents that could occur in such installations were identified and the qualitative and quantitative techniques available for the identification of the risks and for the evaluation of the consequences of each identified accidents were selected. The use of the methodology was illustrated by applying it in two case examples adapted from the literature, involving accidents with inflammable, explosives, and radioactive materials. The computer code MRA - Methodology for Risk Assessment was developed using DELPHI, version 5.0, with the purpose of

  11. Associating Crash Avoidance Maneuvers with Driver Attributes and Accident Characteristics: A Mixed Logit Model Approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study focuses on the propensity of drivers to engage in crash avoidance maneuvers in relation to driver attributes, critical events, crash characteristics, vehicles involved, road characteristics and environmental attributes. Five alternative actions involving emergency lateral and speed...... as from the key role of the ability of drivers to perform effective corrective maneuvers for the success of automated in-vehicle warning and driver assistance systems. The analysis is conducted by means of a mixed logit model that accommodates correlations across alternatives and heteroscedasticity. Data...... for the analysis are retrieved from the General Estimates System (GES) crash database for the year 2009. Results show that (i) the nature of the critical event that made the crash imminent influences the choice of crash avoidance maneuvers, (ii) women and elderly have a lower propensity to conduct crash avoidance...

  12. Analysis of Maximum Reasonably Foreseeable Accidents for the Yucca Mountain Draft Environmental Impact Statement (DEIS)

    Energy Technology Data Exchange (ETDEWEB)

    S.B. Ross; R.E. Best; S.J. Maheras; T.I. McSweeney

    2001-08-17

    Accidents could occur during the transportation of spent nuclear fuel and high-level radioactive waste. This paper describes the risks and consequences to the public from accidents that are highly unlikely but that could have severe consequences. The impact of these accidents would include those to a collective population and to hypothetical maximally exposed individuals (MEIs). This document discusses accidents with conditions that have a chance of occurring more often than 1 in 10 million times in a year, called ''maximum reasonably foreseeable accidents''. Accidents and conditions less likely than this are not considered to be reasonably foreseeable.

  13. Weather modeling for hazard and consequence assessment operations during the 2006 Winter Olympic Games

    Science.gov (United States)

    Hayes, P.; Trigg, J. L.; Stauffer, D.; Hunter, G.; McQueen, J.

    2006-05-01

    Consequence assessment (CA) operations are those processes that attempt to mitigate negative impacts of incidents involving hazardous materials such as chemical, biological, radiological, nuclear, and high explosive (CBRNE) agents, facilities, weapons, or transportation. Incident types range from accidental spillage of chemicals at/en route to/from a manufacturing plant, to the deliberate use of radiological or chemical material as a weapon in a crowded city. The impacts of these incidents are highly variable, from little or no impact to catastrophic loss of life and property. Local and regional scale atmospheric conditions strongly influence atmospheric transport and dispersion processes in the boundary layer, and the extent and scope of the spread of dangerous materials in the lower levels of the atmosphere. Therefore, CA personnel charged with managing the consequences of CBRNE incidents must have detailed knowledge of current and future weather conditions to accurately model potential effects. A meteorology team was established at the U.S. Defense Threat Reduction Agency (DTRA) to provide weather support to CA personnel operating DTRA's CA tools, such as the Hazard Prediction and Assessment Capability (HPAC) tool. The meteorology team performs three main functions: 1) regular provision of meteorological data for use by personnel using HPAC, 2) determination of the best performing medium-range model forecast for the 12 - 48 hour timeframe and 3) provision of real-time help-desk support to users regarding acquisition and use of weather in HPAC CA applications. The normal meteorology team operations were expanded during a recent modeling project which took place during the 2006 Winter Olympic Games. The meteorology team took advantage of special weather observation datasets available in the domain of the Winter Olympic venues and undertook a project to improve weather modeling at high resolution. The varied and complex terrain provided a special challenge to the

  14. Severe accident simulation at Olkiuoto

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkonen, H.; Saarenpaeae, T. [Teollisuuden Voima Oy (TVO), Olkiluoto (Finland); Cliff Po, L.C. [Micro-Simulation Technology, Montville, NJ (United States)

    1995-09-01

    A personal computer-based simulator was developed for the Olkiluoto nuclear plant in Finland for training in severe accident management. The generic software PCTRAN was expanded to model the plant-specific features of the ABB Atom designed BWR including its containment over-pressure protection and filtered vent systems. Scenarios including core heat-up, hydrogen generation, core melt and vessel penetration were developed in this work. Radiation leakage paths and dose rate distribution are presented graphically for operator use in diagnosis and mitigation of accidents. Operating on an graphically for operator use in diagnosis and mitigation of accidents. Operating on an 486 DX2-66, PCTRAN-TVO achieves a speed about 15 times faster than real-time. A convenient and user-friendly graphic interface allows full interactive control. In this paper a review of the component models and verification runs are presented.

  15. Review of current severe accident management approaches in Europe and identification of related modelling requirements for the computer code ASTEC V2.1

    Energy Technology Data Exchange (ETDEWEB)

    Hermsmeyer, S. [European Commission JRC, Petten (Netherlands). Inst. for Energy and Transport; Herranz, L.E.; Iglesias, R. [CIEMAT, Madrid (Spain); and others

    2015-07-15

    The severe accident at the Fukushima-Daiichi nuclear power plant (NPP) has led to a worldwide review of nuclear safety approaches and is bringing a refocussing of R and D in the field. To support these efforts several new Euratom FP7 projects have been launched. The CESAM project focuses on the improvement of the ASTEC computer code. ASTEC is jointly developed by IRSN and GRS and is considered as the European reference code for Severe Accident Analyses since it capitalizes knowledge from the extensive Euro-pean R and D in the field. The project aims at the code's enhancement and extension for use in Severe Accident Management (SAM) analysis of the NPPs of Generation II-III presently under operation or foreseen in the near future in Europe, spent fuel pools included. The work reported here is concerned with the importance, for the further development of the code, of SAM strategies to be simulated. To this end, SAM strategies applied in the EU have been compiled. This compilation is mainly based on the public information made available in the frame of the EU ''stress tests'' for NPPs and has been complemented by information pro-vided by the different CESAM partners. The context of SAM is explained and the strategies are presented. The modelling capabilities for the simulation of these strategies in the current production version 2.0 of ASTEC are discussed. Furthermore, the requirements for the next version of ASTEC V2.1 that is supported in the CESAM project are highlighted. They are a necessary complement to the list of code improvements that is drawn from consolidating new fields of application, like SFP and BWR model enhancements, and from new experimental results on severe accident phenomena.

  16. Explosion risks and consequences for tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den

    2014-01-01

    Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for t

  17. Simple physics-based models of compensatory plant water uptake: concepts and eco-hydrological consequences

    Directory of Open Access Journals (Sweden)

    N. J. Jarvis

    2011-11-01

    Full Text Available Many land surface schemes and simulation models of plant growth designed for practical use employ simple empirical sub-models of root water uptake that cannot adequately reflect the critical role water uptake from sparsely rooted deep subsoil plays in meeting atmospheric transpiration demand in water-limited environments, especially in the presence of shallow groundwater. A failure to account for this so-called "compensatory" water uptake may have serious consequences for both local and global modeling of water and energy fluxes, carbon balances and climate. Some purely empirical compensatory root water uptake models have been proposed, but they are of limited use in global modeling exercises since their parameters cannot be related to measurable soil and vegetation properties. A parsimonious physics-based model of uptake compensation has been developed that requires no more parameters than empirical approaches. This model is described and some aspects of its behavior are illustrated with the help of example simulations. These analyses demonstrate that hydraulic lift can be considered as an extreme form of compensation and that the degree of compensation is principally a function of soil capillarity and the ratio of total effective root length to potential transpiration. Thus, uptake compensation increases as root to leaf area ratios increase, since potential transpiration depends on leaf area. Results of "scenario" simulations for two case studies, one at the local scale (riparian vegetation growing above shallow water tables in seasonally dry or arid climates and one at a global scale (water balances across an aridity gradient in the continental USA, are presented to illustrate biases in model predictions that arise when water uptake compensation is neglected. In the first case, it is shown that only a compensated model can match the strong relationships between water table depth and leaf area and transpiration observed in riparian forest

  18. Simple physics-based models of compensatory plant water uptake: concepts and eco-hydrological consequences

    Directory of Open Access Journals (Sweden)

    N. J. Jarvis

    2011-07-01

    Full Text Available Many land surface schemes and simulation models of plant growth designed for practical use employ simple empirical sub-models of root water uptake that cannot adequately reflect the critical role water uptake from sparsely rooted deep subsoil plays in meeting atmospheric transpiration demand in water-limited environments, especially in the presence of shallow groundwater. A failure to account for this so-called "compensatory" water uptake may have serious consequences for both local and global modeling of water and energy fluxes, carbon balances and climate. Some purely empirical compensatory root water uptake models have been proposed, but they are of limited use in global modeling exercises since their parameters cannot be related to measurable soil and vegetation properties. Parsimonious physics-based models of uptake compensation have been developed that require no more parameters than empirical approaches. These models are described and compared from a conceptual point of view and some aspects of their behavior, including the phenomenon of hydraulic lift, are illustrated with the help of example simulations. These analyses demonstrate that the degree of compensation is a function of soil capillarity and the ratio of total effective root length to potential transpiration. Thus, uptake compensation increases as root to leaf area ratios increase, since potential transpiration depends on leaf area. Results of "scenario" simulations for two case studies, one at the local scale (riparian vegetation growing above shallow water tables in seasonally dry or arid climates and one at a global scale (water balances across an aridity gradient in the continental USA, are presented to illustrate biases in model predictions that arise when water uptake compensation is neglected. In the first case, it is shown that only a compensated model can match the strong relationships between water table depth and leaf area and transpiration observed in riparian forest

  19. Stressors, stress and stress consequences during long-duration manned space missions: a descriptive model

    Science.gov (United States)

    Geuna, Stefano; Brunelli, Francesco; Perino, Maria A.

    Keeping crew members in good health is a major factor in the success or failure of long-duration manned space missions. Among the many possible agents that can affect the crew's general well-being, stress is certainly one of the most critical because of its implications on human health and performance, both physical and mental. Nevertheless, very few studies have been performed on this fundamental issue and none of them has addressed it in its entirity, considering its diverse physical and psychological aspects. In this work, a descriptive model is proposed to expound the mechanism and sequence of events which mediate stress. A critical analysis of the information provided by past manned spaceflights and by dedicated research performed in analogous environments is presented, and an extrapolation of the available data on human stress in such extreme conditions is proposed. Both internal and external stressors have been identified, at physical and psychosocial levels, thus providing the basis for their early detection and preventive reduction. The possible negative consequences of stress that may lead to disease in crewmembers are described. Finally, the most effective instruments which may be of help in reducing space-related human stress and treating its negative consequences are suggested.

  20. Uncertainties in offsite consequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Young, M.L.; Harper, F.T.; Lui, C.H.

    1996-03-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequences from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the U.S. Nuclear Regulatory Commission and the European Commission began co-sponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables using a formal expert judgment elicitation and evaluation process. This paper focuses on the methods used in and results of this on-going joint effort.

  1. Cold Vacuum Drying facility design basis accident analysis documentation

    Energy Technology Data Exchange (ETDEWEB)

    CROWE, R.D.

    2000-08-08

    This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report (FSAR), ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR. The calculations in this document address the design basis accidents (DBAs) selected for analysis in HNF-3553, ''Spent Nuclear Fuel Project Final Safety Analysis Report'', Annex B, ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' The objective is to determine the quantity of radioactive particulate available for release at any point during processing at the Cold Vacuum Drying Facility (CVDF) and to use that quantity to determine the amount of radioactive material released during the DBAs. The radioactive material released is used to determine dose consequences to receptors at four locations, and the dose consequences are compared with the appropriate evaluation guidelines and release limits to ascertain the need for preventive and mitigative controls.

  2. Mean-field theory for car accidents

    Science.gov (United States)

    Huang, Ding-Wei; Tseng, Wei-Chung

    2001-11-01

    We study analytically the occurrence of car accidents in the Nagel-Schreckenberg traffic model. We obtain exact results for the occurrence of car accidents Pac as a function of the car density ρ and the degree of stochastic braking p1 in the case of speed limit vmax=1. Various quantities are calculated analytically. The nontrivial limit p1-->0 is discussed.

  3. A study on industrial accident rate forecasting and program development of estimated zero accident time in Korea.

    Science.gov (United States)

    Kim, Tae-gu; Kang, Young-sig; Lee, Hyung-won

    2011-01-01

    To begin a zero accident campaign for industry, the first thing is to estimate the industrial accident rate and the zero accident time systematically. This paper considers the social and technical change of the business environment after beginning the zero accident campaign through quantitative time series analysis methods. These methods include sum of squared errors (SSE), regression analysis method (RAM), exponential smoothing method (ESM), double exponential smoothing method (DESM), auto-regressive integrated moving average (ARIMA) model, and the proposed analytic function method (AFM). The program is developed to estimate the accident rate, zero accident time and achievement probability of an efficient industrial environment. In this paper, MFC (Microsoft Foundation Class) software of Visual Studio 2008 was used to develop a zero accident program. The results of this paper will provide major information for industrial accident prevention and be an important part of stimulating the zero accident campaign within all industrial environments.

  4. Modelling the economic consequences of Marine Protected Areas using the BEMCOM model

    DEFF Research Database (Denmark)

    Hoff, A.; Andersen, J.L.; Christensen, Asbjørn;

    2013-01-01

    Sea. It has several times been suggested to close parts of the sandeel fishery in the North Sea out of concern for other species feeding on sandeel and/or spawning in the sandeel habitats. The economic effects of such closures have been assessed using BEMCOM. The results indicate that the model yields...... the question ‘what’s best?’, i.e. finds the overall optimal effort allocation, from an economic point of view, between multiple harvesting fleets fishing under a subset of restrictions on catches and effort levels. The BEMCOM model is described and applied to the case of the Danish sandeel fishery in the North...

  5. Radiation protection: an analysis of thyroid blocking. [Effectiveness of KI in reducing radioactive uptake following potential reactor accident

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, D C; Blond, R M

    1980-01-01

    An analysis was performed to provide guidance to policymakers concerning the effectiveness of potassium iodide (KI) as a thyroid blocking agent in potential reactor accident situations, the distance to which (or area within which) it should be distributed, and its relative effectiveness compared to other available protective measures. The analysis was performed using the Reactor Safety Study (WASH-1400) consequence model. Four categories of accidents were addressed: gap activity release accident (GAP), GAP without containment isolation, core melt with a melt-through release, and core melt with an atmospheric release. Cost-benefit ratios (US $/thyroid nodule prevented) are given assuming that no other protective measures are taken. Uncertainties due to health effects parameters, accident probabilities, and costs are assessed. The effects of other potential protective measures, such as evacuation and sheltering, and the impact on children (critical population) are evaluated. Finally, risk-benefit considerations are briefly discussed.

  6. Simulation of Containment Pressurization in a Large Break-Loss of Coolant Accident Using Single-Cell and Multicell Models and CONTAIN Code

    Directory of Open Access Journals (Sweden)

    Omid Noori-Kalkhoran

    2016-10-01

    Full Text Available Since the inception of nuclear power as a commercial energy source, safety has been recognized as a prime consideration in the design, construction, operation, maintenance, and decommissioning of nuclear power plants. The release of radioactivity to the environment requires the failure of multiple safety systems and the breach of three physical barriers: fuel cladding, the reactor cooling system, and containment. In this study, nuclear reactor containment pressurization has been modeled in a large break-loss of coolant accident (LB-LOCA by programming single-cell and multicell models in MATLAB. First, containment has been considered as a control volume (single-cell model. In addition, spray operation has been added to this model. In the second step, the single-cell model has been developed into a multicell model to consider the effects of the nodalization and spatial location of cells in the containment pressurization in comparison with the single-ce