WorldWideScience

Sample records for accident source term

  1. Source term analyses under severe accidents for KNGR

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yong Mann; Park, Soo Yong

    2001-03-01

    In this study, in-containment source term for LOFW (Loss of Feed Water), which has appeared the most frequent core melt accident, is calculated and compared with NUREG-1465 source term. This study provides not only new source term data using MELCOR1.8.4 and its state-of-the-art models but also evaluating basis of KNGR design and its mitigation capability under severe accidents. As the selected accident is identical with LOFW-S17, which has been analyzed using MAAP by KEPCO with only difference of 2 SITs, mutual comparison of the results is especially expected.

  2. Revised accident source terms for light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soffer, L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  3. Advanced sodium fast reactor accident source terms :

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Dana Auburn; Clement, Bernard; Denning, Richard; Ohno, Shuji; Zeyen, Roland

    2010-09-01

    An expert opinion elicitation has been used to evaluate phenomena that could affect releases of radionuclides during accidents at sodium-cooled fast reactors. The intent was to identify research needed to develop a mechanistic model of radionuclide release for licensing and risk assessment purposes. Experts from the USA, France, the European Union, and Japan identified phenomena that could affect the release of radionuclides under hypothesized accident conditions. They qualitatively evaluated the importance of these phenomena and the need for additional experimental research. The experts identified seven phenomena that are of high importance and have a high need for additional experimental research: High temperature release of radionuclides from fuel during an energetic event Energetic interactions between molten reactor fuel and sodium coolant and associated transfer of radionuclides from the fuel to the coolant Entrainment of fuel and sodium bond material during the depressurization of a fuel rod with breached cladding Rates of radionuclide leaching from fuel by liquid sodium Surface enrichment of sodium pools by dissolved and suspended radionuclides Thermal decomposition of sodium iodide in the containment atmosphere Reactions of iodine species in the containment to form volatile organic iodides. Other issues of high importance were identified that might merit further research as development of the mechanistic model of radionuclide release progressed.

  4. Source term analysis for a nuclear submarine accident

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.J.; Hugron, J.J.M.R. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)

    1999-07-01

    A source term analysis has been conducted to determine the activity release into the environment as a result of a large-break loss-of-coolant accident aboard a visiting nuclear-powered submarine to a Canadian port. This best-estimate analysis considers the fractional release from the core, and fission product transport in the primary heat transport system, primary containment (i.e. reactor compartment) and submarine hull. Physical removal mechanisms such as vapour and aerosol deposition are treated in the calculation. Since a thermalhydraulic analysis indicated that the integrity of the reactor compartment is maintained, release from the reactor compartment will only occur by leakage; however, it is conservatively assumed that the secondary containment is not isolated for a 24-h period where release occurs through an open hatch in the submarine hull. Consequently, during this period, the activity release into the atmosphere is estimated as 4.6 TBq, leading to a maximum individual dose equivalent of 0.5 mSv at 800 metres from the berthing location. This activity release is comparable to that obtained in the BEREX TSA study (for a similar accident scenario) but is four orders of magnitude less than that reported in the earlier Davis study where, unrealistically, no credit had been taken for the containment system or for any physical removal processes. (author)

  5. Review of Past Nuclear Accidents: Source Terms and Recorded Gamma-Ray Spectra

    OpenAIRE

    Sanderson, D.C.W.; Cresswell, A.; Allyson, J.D.; McConville, P.; Department of the Environment: Radioactive Substances Division

    1997-01-01

    Airborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. A literature search on past nuclear accidents has been conducted to define the source terms which have been experienced so far. Selected gamma ray spectra recorded after past accidents have also been collated to examine the complexity of observed behaviour.

  6. Project on Transfer Mechanism of Radioactive Source Term Under Severe Accident

    Institute of Scientific and Technical Information of China (English)

    SUN; Xue-ting; JI; Song-tao; CHEN; Lin-lin

    2012-01-01

    <正>The "Transfer mechanism of radioactive source term under severe accident" is a sub-project of the research program of "Mechanism and phenomenology of severe accident". An aerosol transfer mechanism experimental facility is built to simulate the passive containment cooling system (PCCS) of advanced pressurizer reactors to research effects to the transfer process of fission products under severe accident. An advanced CFD method is also utilized to research the effects. The objective of this project is to understand

  7. Quantification of severe accident source terms of a Westinghouse 3-loop plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee Min [Department of Engineering and System Science, and Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec II, Kung Fu Road, Hsinchu, Taiwan (China)], E-mail: mlee@mail.ess.nthu.edu.tw; Ko, Y.-C. [Department of Engineering and System Science, and Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec II, Kung Fu Road, Hsinchu, Taiwan, ROC (China)

    2008-04-15

    Integrated severe accident analysis codes are used to quantify the source terms of the representative sequences identified in PSA study. The characteristics of these source terms depend on the detail design of the plant and the accident scenario. A historical perspective of radioactive source term is provided. The grouping of radionuclides in different source terms or source term quantification tools based on TID-14844, NUREG-1465, and WASH-1400 is compared. The radionuclides release phenomena and models adopted in the integrated severe accident analysis codes of STCP and MAAP4 are described. In the present study, the severe accident source terms for risk quantification of Maanshan Nuclear Power Plant of Taiwan Power Company are quantified using MAAP 4.0.4 code. A methodology is developed to quantify the source terms of each source term category (STC) identified in the Level II PSA analysis of the plant. The characteristics of source terms obtained are compared with other source terms. The plant analyzed employs a Westinghouse designed 3-loop pressurized water reactor (PWR) with large dry containment.

  8. Source terms for analysis of accidents at a high level waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Mubayi, V.; Davis, R.E.; Youngblood, R.

    1989-01-01

    This paper describes an approach to identifying source terms from possible accidents during the preclosure phase of a high-level nuclear waste repository. A review of the literature on repository safety analyses indicated that source term estimation is in a preliminary stage, largely based on judgement-based scoping analyses. The approach developed here was to partition the accident space into domains defined by certain threshold values of temperature and impact energy density which may arise in potential accidents and specify release fractions of various radionuclides, present in the waste form, in each domain. Along with a more quantitative understanding of accident phenomenology, this approach should help in achieving a clearer perspective on scenarios important to preclosure safety assessments of geologic repositories. 18 refs., 3 tabs.

  9. Accident source terms for boiling water reactors with high burnup cores.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Powers, Dana Auburn; Leonard, Mark Thomas

    2007-11-01

    The primary objective of this report is to provide the technical basis for development of recommendations for updates to the NUREG-1465 Source Term for BWRs that will extend its applicability to accidents involving high burnup (HBU) cores. However, a secondary objective is to re-examine the fundamental characteristics of the prescription for fission product release to containment described by NUREG-1465. This secondary objective is motivated by an interest to understand the extent to which research into the release and behaviors of radionuclides under accident conditions has altered best-estimate calculations of the integral response of BWRs to severe core damage sequences and the resulting radiological source terms to containment. This report, therefore, documents specific results of fission product source term analyses that will form the basis for the HBU supplement to NUREG-1465. However, commentary is also provided on observed differences between the composite results of the source term calculations performed here and those reflected NUREG-1465 itself.

  10. CFD Analysis of Migration Mechanism of Source Term Under Severe Accident

    Institute of Scientific and Technical Information of China (English)

    CHEN; Lin-lin; SUN; Xue-ting; JI; Song-tao

    2013-01-01

    The analysis of the migration of source term under severe accident is one of the important aspects of‘Studies on Migration Mechanism of the Source Term under Severe Accident’,which is a significant task of the National Large Advanced PWR Research Program.This research aims at building up a method for analyzing fission product behavior in the containment with CFD code.The effect of PCCS(Passive

  11. Development of the source term PIRT based on findings during Fukushima Daiichi NPPs accident

    Energy Technology Data Exchange (ETDEWEB)

    Suehiro, Shoichi, E-mail: suehiro-shouichi@tepsys.co.jp [TEPCO SYSTEMS Co., 2-37-28 Eitai, Koto-Ku, Tokyo 135-0034 (Japan); Sugimoto, Jun [Kyoto University, Yoshida Sakyo, Kyoto 606-8501 (Japan); Hidaka, Akihide [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Okada, Hidetoshi [The Institute of Applied Energy, 14-2 Nishi-Shimbashi 1-Chome, Minato-ku, Tokyo 105-0003 (Japan); Mizokami, Shinya [Tokyo Electric Power Company, 1-3 Uchisaiwai-cho 1-Chome, Chiyoda-ku, Tokyo 100-8560 (Japan); Okamoto, Koji [The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan)

    2015-05-15

    Highlights: • We developed the source term PIRT based on findings during the Fukushima accident. • The FoM is the masses or fractions of radionuclides released into the environment. • 68 phenomena were identified as influencing to the FoM. • Radionuclide release from molten fuel had the highest score in the early phase. • MCCI, iodine chemistry, and chemical form had the highest score in the later phase. - Abstract: Research Expert Committee on Evaluation of Severe Accident of AESJ (Atomic Energy Society of Japan) has developed thermal hydraulic PIRT (Phenomena Identification and Ranking Table) and source term (ST) PIRT based on findings during the Fukushima Daiichi NPPs accident. These PIRTs aim to explore the debris distribution and the current condition in the NPPs with high accuracy and to extract higher priority from the aspect of the sophistication of the analytical technology to predict the severe accident phenomena by the analytical codes. The ST PIRT is divided into 3 phases for time domain and 9 categories for spatial domain. The 68 phenomena have been extracted and the importance from the viewpoint of the source term has been ranked through brainstorming and discussions among experts. The present paper describes the developed ST PIRT list and summarizes the high ranked phenomena in each phase.

  12. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    Energy Technology Data Exchange (ETDEWEB)

    Salay, Michael (U.S. Nuclear Regulatory Commission, Washington, D.C.); Gauntt, Randall O.; Lee, Richard Y. (U.S. Nuclear Regulatory Commission, Washington, D.C.); Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  13. HTGR accident initiation and progression analysis status report. Volume V. AIPA fission product source terms

    Energy Technology Data Exchange (ETDEWEB)

    Alberstein, D.; Apperson, C.E. Jr.; Hanson, D.L.; Myers, B.F.; Pfeiffer, W.W.

    1976-02-01

    The primary objective of the Accident Initiation and Progression Analysis (AIPA) Program is to provide guidance for high-temperature gas-cooled reactor (HTGR) safety research and development. Among the parameters considered in estimating the uncertainties in site boundary doses are uncertainties in fission product source terms generated under normal operating conditions, i.e., fuel body inventories, circulating coolant activity, total plateout activity in the primary circuit, and plateout distributions. The volume presented documents the analyses of these source term uncertainties. The results are used for the detailed consequence evaluations, and they provide the basis for evaluation of fission products important for HTGR maintenance and shielding.

  14. Chemistry aspects of the source term formation for a severe accident in a CANDU type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, A.; Constantin, M. [Institute for Nuclear Research, Pitesti (Romania)

    2013-07-15

    The progression of a severe accident in a CANDU type reactor is slow because the core is surrounded by a large quantity of heavy and light water which acts as a heat sink to remove the decay heat. Therefore, the source term formation is a complex and long process involving fission products transport and releasing in the fuel matrix, thermal hydraulics of the transport fluid in the primary heat system and containment, deposition and transport of fission products, chemistry including the interaction with the dousing system, structural materials and paints, etc. The source term is strongly dependent on initial conditions and accident type. The paper presents chemistry aspects for a severe accident in a CANDU type reactor, in terms of the retention in the primary heat system. After releasing from the fuel elements, the fission products suffer a multitude of phenomena before they are partly transferred into the containment region. The most important species involved in the deposition were identified. At the same time, the influence of the break position in the transfer fractions from the primary heat system to the containment was investigated. (orig.)

  15. Severe accident source term characteristics for selected Peach Bottom sequences predicted by the MELCOR Code

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, J.J. [Oak Ridge National Lab., TN (United States)

    1993-09-01

    The purpose of this report is to compare in-containment source terms developed for NUREG-1159, which used the Source Term Code Package (STCP), with those generated by MELCOR to identify significant differences. For this comparison, two short-term depressurized station blackout sequences (with a dry cavity and with a flooded cavity) and a Loss-of-Coolant Accident (LOCA) concurrent with complete loss of the Emergency Core Cooling System (ECCS) were analyzed for the Peach Bottom Atomic Power Station (a BWR-4 with a Mark I containment). The results indicate that for the sequences analyzed, the two codes predict similar total in-containment release fractions for each of the element groups. However, the MELCOR/CORBH Package predicts significantly longer times for vessel failure and reduced energy of the released material for the station blackout sequences (when compared to the STCP results). MELCOR also calculated smaller releases into the environment than STCP for the station blackout sequences.

  16. Effect of hypoiodous acid volatility on the iodine source term in reactor accidents

    Energy Technology Data Exchange (ETDEWEB)

    Routamo, T. [Imatran Voima Oy, Vantaa (Finland)

    1996-12-01

    A FORTRAN code ACT WATCH has been developed to establish an improved understanding of essential radionuclide behaviour mechanisms, especially related to iodine chemistry, in reactor accidents. The accident scenarios calculated in this paper are based on the Loss of Coolant accident at the Loviisa Nuclear Power Plant. The effect of different airborne species, especially HIO, on the iodine source term has been studied. The main cause of the high HIO release in the system modelled is the increase of I{sub 2} hydrolysis rate along with the temperature increase, which accelerates HIO production. Due to the high radiation level near the reactor core, I{sub 2} is produced from I{sup -}very rapidly. High temperature in the reactor coolant causes I{sub 2} to be transformed into HIO and through the boiling of the coolant volatile I{sub 2} and HIO are transferred efficiently into the gas phase. High filtration efficiency for particulate iodine causes I{sup -} release to be much lower than those of I{sub 2} and HIO. (author) 15 figs., 1 tab., refs.

  17. Methods to prevent the source term of methyl lodide during a core melt accident

    Energy Technology Data Exchange (ETDEWEB)

    Karhu, A. [VTT Energy (Finland)

    1999-11-01

    The purpose of this literature review is to gather available information of the methods to prevent a source term of methyl iodide during a core melt accident. The most widely studied methods for nuclear power plants include the impregnated carbon filters and alkaline additives and sprays. It is indicated that some deficiencies of these methods may emerge. More reactive impregnants and additives could make a great improvement. As a new method in the field of nuclear applications, the potential of transition metals to decompose methyl iodide, is introduced in this review. This area would require an additional research, which could elucidate the remaining questions of the reactions. The ionization of the gaseous methyl iodide by corona-discharge reactors is also shortly described. (au)

  18. 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....

  19. Estimation of marine source-term following Fukushima Dai-ichi accident.

    Science.gov (United States)

    Bailly du Bois, P; Laguionie, P; Boust, D; Korsakissok, I; Didier, D; Fiévet, B

    2012-12-01

    Contamination of the marine environment following the accident in the Fukushima Dai-ichi nuclear power plant represented the most important artificial radioactive release flux into the sea ever known. The radioactive marine pollution came from atmospheric fallout onto the ocean, direct release of contaminated water from the plant and transport of radioactive pollution from leaching through contaminated soil. In the immediate vicinity of the plant (less than 500 m), the seawater concentrations reached 68,000 Bq.L(-1) for (134)Cs and (137)Cs, and exceeded 100,000 Bq.L(-1) for (131)I in early April. Due to the accidental context of the releases, it is difficult to estimate the total amount of radionuclides introduced into seawater from data obtained in the plant. An evaluation is proposed here, based on measurements performed in seawater for monitoring purposes. Quantities of (137)Cs in seawater in a 50-km area around the plant were calculated from interpolation of seawater measurements. The environmental halftime of seawater in this area is deduced from the time-evolution of these quantities. This halftime appeared constant at about 7 days for (137)Cs. These data allowed estimation of the amount of principal marine inputs and their evolution in time: a total of 27 PBq (12 PBq-41 PBq) of (137)Cs was estimated up to July 18. Even though this main release may be followed by residual inputs from the plant, river runoff and leakage from deposited sediments, it represents the principal source-term that must be accounted for future studies of the consequences of the accident on marine systems. The (137)Cs from Fukushima will remain detectable for several years throughout the North Pacific, and (137)Cs/(134)Cs ratio will be a tracer for future studies.

  20. A comparison of world-wide uses of severe reactor accident source terms

    Energy Technology Data Exchange (ETDEWEB)

    Ang, M.L. [NNC Ltd., Knutsford (United Kingdom); Frid, W. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Kersting, E.J.; Friederichs, H.G. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany); Lee, R.Y. [Nuclear Regulatory Commission, Washington, DC (United States); Meyer-Heine, A. [CEA Centre d`Etudes de Cadarache, Saint Paul Lez Durance (France); Powers, D.A. [Sandia National Labs., Albuquerque, NM (United States); Soda, K. [Japan Atomic Energy Research Inst., Tokyo (Japan); Sweet, D. [AEA Technology, Winfrith (United Kingdom)

    1994-09-01

    The definitions of source terms to reactor containments and source terms to the environment are discussed. A comparison is made between the TID-14844 example source term and the alternative source term described in NUREG-1465. Comparisons of these source terms to the containments and those used in France, Germany, Japan, Sweden, and the United Kingdom are made. Source terms to the environment calculated in NUREG-1500 and WASH-1400 are discussed. Again, these source terms are compared to those now being used in France, Germany, Japan, Sweden, and the United Kingdom. It is concluded that source terms to the containment suggested in NUREG-1465 are not greatly more conservative than those used in other countries. Technical bases for the source terms are similar. The regulatory use of the current understanding of radionuclide behavior varies among countries.

  1. 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.

  2. Recent advances in the source term area within the SARNET European severe accident research network

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L.E., E-mail: luisen.herranz@ciemat.es [Centro de Investigaciones Energeticas Medio Ambientales y Tecnologica, CIEMAT, Avda. Complutense 40, E-28040 Madrid (Spain); Haste, T. [Institut de Radioprotection et de Sûreté Nucléaire, IRSN, BP 3, F-13115 St Paul lez Durance Cedex (France); Kärkelä, T. [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT Espoo (Finland)

    2015-07-15

    Highlights: • Main achievements of source term research in SARNET are given. • Emphasis on the radiologically important iodine and ruthenium fission products. • Conclusions on FP release, transport in the RCS and containment behaviour. • Significance of large-scale integral experiments to validate the analyses used. • A thorough list of the most recent references on source term research results. - Abstract: Source Term has been one of the main research areas addressed within the SARNET network during the 7th EC Framework Programme of EURATOM. The entire source term domain was split into three major areas: oxidising impact on source term, iodine chemistry in the reactor coolant system and containment and data and code assessment. The present paper synthesises the main technical outcome stemming from the SARNET FWP7 project in the area of source term and includes an extensive list of references in which deeper insights on specific issues may be found. Besides, based on the analysis of the current state of the art, an outlook of future source term research is outlined, where major changes in research environment are discussed (i.e., the end of the Phébus FP project; the end of the SARNET projects; and the launch of HORIZON 2020). Most probably research projects will be streamlined towards: release and transport under oxidising conditions, containment chemistry, existing and innovative filtered venting systems and others. These will be in addition to a number of projects that have been completed or are ongoing under different national and international frameworks, like VERDON, CHIP and EPICUR started under the International Source Term Programme (ISTP), the OECD/CSNI programmes BIP, BIP2, STEM, THAI and THAI2, and the French national programme MIRE. The experimental PASSAM project under the 7th EC Framework programme, focused on source term mitigation systems, is highlighted as a good example of a project addressing potential enhancement of safety systems

  3. Accident source terms for pressurized water reactors with high-burnup cores calculated using MELCOR 1.8.5.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Powers, Dana Auburn; Ashbaugh, Scott G.; Leonard, Mark Thomas; Longmire, Pamela

    2010-04-01

    In this study, risk-significant pressurized-water reactor severe accident sequences are examined using MELCOR 1.8.5 to explore the range of fission product releases to the reactor containment building. Advances in the understanding of fission product release and transport behavior and severe accident progression are used to render best estimate analyses of selected accident sequences. Particular emphasis is placed on estimating the effects of high fuel burnup in contrast with low burnup on fission product releases to the containment. Supporting this emphasis, recent data available on fission product release from high-burnup (HBU) fuel from the French VERCOR project are used in this study. The results of these analyses are treated as samples from a population of accident sequences in order to employ approximate order statistics characterization of the results. These trends and tendencies are then compared to the NUREG-1465 alternative source term prescription used today for regulatory applications. In general, greater differences are observed between the state-of-the-art calculations for either HBU or low-burnup (LBU) fuel and the NUREG-1465 containment release fractions than exist between HBU and LBU release fractions. Current analyses suggest that retention of fission products within the vessel and the reactor coolant system (RCS) are greater than contemplated in the NUREG-1465 prescription, and that, overall, release fractions to the containment are therefore lower across the board in the present analyses than suggested in NUREG-1465. The decreased volatility of Cs2MoO4 compared to CsI or CsOH increases the predicted RCS retention of cesium, and as a result, cesium and iodine do not follow identical behaviors with respect to distribution among vessel, RCS, and containment. With respect to the regulatory alternative source term, greater differences are observed between the NUREG-1465 prescription and both HBU and LBU predictions than exist between HBU and LBU

  4. Review of the status of validation of the computer codes used in the severe accident source term reassessment study (BMI-2104). [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Kress, T. S. [comp.

    1985-04-01

    The determination of severe accident source terms must, by necessity it seems, rely heavily on the use of complex computer codes. Source term acceptability, therefore, rests on the assessed validity of such codes. Consequently, one element of NRC's recent efforts to reassess LWR severe accident source terms is to provide a review of the status of validation of the computer codes used in the reassessment. The results of this review is the subject of this document. The separate review documents compiled in this report were used as a resource along with the results of the BMI-2104 study by BCL and the QUEST study by SNL to arrive at a more-or-less independent appraisal of the status of source term modeling at this time.

  5. Analysis of accident sequences and source terms at treatment and storage facilities for waste generated by US Department of Energy waste management operations

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Nabelssi, B.; Roglans-Ribas, J.; Folga, S.; Policastro, A.; Freeman, W.; Jackson, R.; Mishima, J.; Turner, S.

    1996-12-01

    This report documents the methodology, computational framework, and results of facility accident analyses performed for the US Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). The accident sequences potentially important to human health risk are specified, their frequencies assessed, and the resultant radiological and chemical source terms evaluated. A personal-computer-based computational framework and database have been developed that provide these results as input to the WM PEIS for the calculation of human health risk impacts. The WM PEIS addresses management of five waste streams in the DOE complex: low-level waste (LLW), hazardous waste (HW), high-level waste (HLW), low-level mixed waste (LLMW), and transuranic waste (TRUW). Currently projected waste generation rates, storage inventories, and treatment process throughputs have been calculated for each of the waste streams. This report summarizes the accident analyses and aggregates the key results for each of the waste streams. Source terms are estimated, and results are presented for each of the major DOE sites and facilities by WM PEIS alternative for each waste stream. Key assumptions in the development of the source terms are identified. The appendices identify the potential atmospheric release of each toxic chemical or radionuclide for each accident scenario studied. They also discuss specific accident analysis data and guidance used or consulted in this report.

  6. Inverse modeling of the (137)Cs source term of the Fukushima Dai-ichi Nuclear Power Plant accident constrained by a deposition map monitored by aircraft.

    Science.gov (United States)

    Yumimoto, Keiya; Morino, Yu; Ohara, Toshimasa; Oura, Yasuji; Ebihara, Mitsuru; Tsuruta, Haruo; Nakajima, Teruyuki

    2016-11-01

    The amount of (137)Cs released by the Fukushima Dai-ichi Nuclear Power Plant accident of 11 March 2011 was inversely estimated by integrating an atmospheric dispersion model, an a priori source term, and map of deposition recorded by aircraft. An a posteriori source term refined finer (hourly) variations comparing with the a priori term, and estimated (137)Cs released 11 March to 2 April to be 8.12 PBq. Although time series of the a posteriori source term was generally similar to those of the a priori source term, notable modifications were found in the periods when the a posteriori source term was well-constrained by the observations. Spatial pattern of (137)Cs deposition with the a posteriori source term showed better agreement with the (137)Cs deposition monitored by aircraft. The a posteriori source term increased (137)Cs deposition in the Naka-dori region (the central part of Fukushima Prefecture) by 32.9%, and considerably improved the underestimated a priori (137)Cs deposition. Observed values of deposition measured at 16 stations and surface atmospheric concentrations collected on a filter tape of suspended particulate matter were used for validation of the a posteriori results. A great improvement was found in surface atmospheric concentration on 15 March; the a posteriori source term reduced root mean square error, normalized mean error, and normalized mean bias by 13.4, 22.3, and 92.0% for the hourly values, respectively. However, limited improvements were observed in some periods and areas due to the difficulty in simulating accurate wind fields and the lack of the observational constraints.

  7. Review of plutonium aerosol source-term in nuclear accident%核事故条件下钚气溶胶源项研究综述

    Institute of Scientific and Technical Information of China (English)

    刘文杰; 胡八一; 李庆忠

    2011-01-01

    The theoretical and experimental evaluations of plutonium aerosol source-term in nuclear accident are summarized and reviewed in this paper. Hie content of this paper include oxidation mechanism of plutonium, paniculate distribution of plutonium aerosol, aerosol release fraction (ARF) and respirable fraction (RF) of radioactive aerosolization during nuclear accident. The source-term data of three kinds of nuclear accidents which are explosive detonation, static combustion and dynamic combustion have been investigated. The latter two accidental scenes tend to imitate stockpile fire accidents and air transportation disasters wherein the aircrafts and missiles with nuclear devices run up against unexpected fire, crash or in-flight breakup respectively . It is indicated that the aerosolization mechanisms of static combustion and the dynamic combustion without plutonium droplets sparking and explosion are all derived from the oxide particles spilled from the plutonium surface. The size distributions of smaller aerosol particles dispersed with updraft and biggish ones deposited in the soil during static combustion have been measured individually. After that, the full-scale distribution could be obtained in accordance with the combination of the two parts. The investigation of full-scale particu-late distribution in the dynamic combustion scene is unreachable due to the restriction of experimental conditions. The aerosolization distribution in the explosive detonation scene is listed via field test data of Operation Roller Coaster. The source-term of static combustion is lower than the dynamic combustion without sparking and explosion of plutonium droplets, which is based on the thermo dissipation and the loss of oxygen around the plutonium solidity. The dynamic combustion with plutonium droplets sparking and explosion leads to vapor venting and higher source-term. During the explosive detonation the reaction of plutonium oxidation is severest and leads to the highest

  8. Source Term Analysis on Blackout Accident of Marine Reactor%船用堆全船断电事故源项分析

    Institute of Scientific and Technical Information of China (English)

    王伟; 陈力生; 张帆; 蔡琦

    2014-01-01

    Based on the integration program of MELCOR for severe accident analysis , the computational model of a typical marine reactor was established .The creep failure of pressurizer surge tube in the accident of blackout was verified ,and the behavior of the source term before and after the break of surge tube was analyzed .The results show that atmospheric environment and crew would suffer the radioactive harm .The smaller the surge tube break ,the slower the accident process .However ,the external radiation of the crew is slightly increased and the internal radiation is unchanged .The research results can provide a basis on further dose analysis of the source term and the emergency action inside and outside the ship .%本文以一体化严重事故分析程序M ELCOR为研究工具,建立了某型船用堆的计算模型。计算验证了全船断电事故稳压器波动管的蠕变失效,对波动管破损前后的源项行为进行了分析研究。结果表明:波动管失效直接导致对大气环境和船内人员的放射性危害。波动管破损尺寸的减小,导致失效后事故进程减慢,然而对船内人员的外照射危害略有提高,内照射危害相同。本文研究结果可为进一步的源项剂量分析及船内外应急提供依据。

  9. Assessment of severe accident source terms in pressurized-water reactors with a 40% mixed-oxide and 60% low-enriched uranium core using MELCOR 1.8.5.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Goldmann, Andrew S. (Texas A& M University, College Station, TX); Wagner, Kenneth C.; Powers, Dana Auburn; Ashbaugh, Scott G.; Longmire, Pamela

    2010-04-01

    As part of a Nuclear Regulatory Commission (NRC) research program to evaluate the impact of using mixed-oxide (MOX) fuel in commercial nuclear power plants, a study was undertaken to evaluate the impact of the usage of MOX fuel on the consequences of postulated severe accidents. A series of 23 severe accident calculations was performed using MELCOR 1.8.5 for a four-loop Westinghouse reactor with an ice condenser containment. The calculations covered five basic accident classes that were identified as the risk- and consequence-dominant accident sequences in plant-specific probabilistic risk assessments for the McGuire and Catawba nuclear plants, including station blackouts and loss-of-coolant accidents of various sizes, with both early and late containment failures. Ultimately, the results of these MELCOR simulations will be used to provide a supplement to the NRC's alternative source term described in NUREG-1465. Source term magnitude and timing results are presented consistent with the NUREG-1465 format. For each of the severe accident release phases (coolant release, gap release, in-vessel release, ex-vessel release, and late in-vessel release), source term timing information (onset of release and duration) is presented. For all release phases except for the coolant release phase, magnitudes are presented for each of the NUREG-1465 radionuclide groups. MELCOR results showed variation of noble metal releases between those typical of ruthenium (Ru) and those typical of molybdenum (Mo); therefore, results for the noble metals were presented for Ru and Mo separately. The collection of the source term results can be used as the basis to develop a representative source term (across all accident types) that will be the MOX supplement to NUREG-1465.

  10. Analysis of accident sequences and source terms at waste treatment and storage facilities for waste generated by U.S. Department of Energy Waste Management Operations, Volume 3: Appendixes C-H

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Nabelssi, B.; Roglans-Ribas, J. [and others

    1995-04-01

    This report contains the Appendices for the Analysis of Accident Sequences and Source Terms at Waste Treatment and Storage Facilities for Waste Generated by the U.S. Department of Energy Waste Management Operations. The main report documents the methodology, computational framework, and results of facility accident analyses performed as a part of the U.S. Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). The accident sequences potentially important to human health risk are specified, their frequencies are assessed, and the resultant radiological and chemical source terms are evaluated. A personal computer-based computational framework and database have been developed that provide these results as input to the WM PEIS for calculation of human health risk impacts. This report summarizes the accident analyses and aggregates the key results for each of the waste streams. Source terms are estimated and results are presented for each of the major DOE sites and facilities by WM PEIS alternative for each waste stream. The appendices identify the potential atmospheric release of each toxic chemical or radionuclide for each accident scenario studied. They also provide discussion of specific accident analysis data and guidance used or consulted in this report.

  11. Detailed source term estimation of atmospheric release during the Fukushima Dai-ichi nuclear power plant accident by coupling atmospheric and oceanic dispersion models

    Science.gov (United States)

    Katata, Genki; Chino, Masamichi; Terada, Hiroaki; Kobayashi, Takuya; Ota, Masakazu; Nagai, Haruyasu; Kajino, Mizuo

    2014-05-01

    Temporal variations of release amounts of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident and their dispersion process are essential to evaluate the environmental impacts and resultant radiological doses to the public. Here, we estimated a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data and coupling atmospheric and oceanic dispersion simulations by WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN developed by the authors. New schemes for wet, dry, and fog depositions of radioactive iodine gas (I2 and CH3I) and other particles (I-131, Te-132, Cs-137, and Cs-134) were incorporated into WSPEEDI-II. The deposition calculated by WSPEEDI-II was used as input data of ocean dispersion calculations by SEA-GEARN. The reverse estimation method based on the simulation by both models assuming unit release rate (1 Bq h-1) was adopted to estimate the source term at the FNPP1 using air dose rate, and air sea surface concentrations. The results suggested that the major release of radionuclides from the FNPP1 occurred in the following periods during March 2011: afternoon on the 12th when the venting and hydrogen explosion occurred at Unit 1, morning on the 13th after the venting event at Unit 3, midnight on the 14th when several openings of SRV (steam relief valve) were conducted at Unit 2, morning and night on the 15th, and morning on the 16th. The modified WSPEEDI-II using the newly estimated source term well reproduced local and regional patterns of air dose rate and surface deposition of I-131 and Cs-137 obtained by airborne observations. Our dispersion simulations also revealed that the highest radioactive contamination areas around FNPP1 were created from 15th to 16th March by complicated interactions among rainfall (wet deposition), plume movements, and phase properties (gas or particle) of I-131 and release rates

  12. 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.

  13. An uncertainty analysis of the hydrogen source term for a station blackout accident in Sequoyah using MELCOR 1.8.5

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Bixler, Nathan E.; Wagner, Kenneth Charles.

    2014-03-01

    A methodology for using the MELCOR code with the Latin Hypercube Sampling method was developed to estimate uncertainty in various predicted quantities such as hydrogen generation or release of fission products under severe accident conditions. In this case, the emphasis was on estimating the range of hydrogen sources in station blackout conditions in the Sequoyah Ice Condenser plant, taking into account uncertainties in the modeled physics known to affect hydrogen generation. The method uses user-specified likelihood distributions for uncertain model parameters, which may include uncertainties of a stochastic nature, to produce a collection of code calculations, or realizations, characterizing the range of possible outcomes. Forty MELCOR code realizations of Sequoyah were conducted that included 10 uncertain parameters, producing a range of in-vessel hydrogen quantities. The range of total hydrogen produced was approximately 583kg 131kg. Sensitivity analyses revealed expected trends with respected to the parameters of greatest importance, however, considerable scatter in results when plotted against any of the uncertain parameters was observed, with no parameter manifesting dominant effects on hydrogen generation. It is concluded that, with respect to the physics parameters investigated, in order to further reduce predicted hydrogen uncertainty, it would be necessary to reduce all physics parameter uncertainties similarly, bearing in mind that some parameters are inherently uncertain within a range. It is suspected that some residual uncertainty associated with modeling complex, coupled and synergistic phenomena, is an inherent aspect of complex systems and cannot be reduced to point value estimates. The probabilistic analyses such as the one demonstrated in this work are important to properly characterize response of complex systems such as severe accident progression in nuclear power plants.

  14. Atmospheric discharge and dispersion of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant accident. Part II: verification of the source term and analysis of regional-scale atmospheric dispersion.

    Science.gov (United States)

    Terada, Hiroaki; Katata, Genki; Chino, Masamichi; Nagai, Haruyasu

    2012-10-01

    Regional-scale atmospheric dispersion simulations were carried out to verify the source term of (131)I and (137)Cs estimated in our previous studies, and to analyze the atmospheric dispersion and surface deposition during the Fukushima Dai-ichi Nuclear Power Plant accident. The accuracy of the source term was evaluated by comparing the simulation results with measurements of daily and monthly surface depositions (fallout) over land in eastern Japan from March 12 to April 30, 2011. The source term was refined using observed air concentrations of radionuclides for periods when there were significant discrepancies between the calculated and measured daily surface deposition, and when environmental monitoring data, which had not been used in our previous studies, were now available. The daily surface deposition using the refined source term was predicted mostly to within a factor of 10, and without any apparent bias. Considering the errors in the model prediction, the estimated source term is reasonably accurate during the period when the plume flowed over land in Japan. The analysis of regional-scale atmospheric dispersion and deposition suggests that the present distribution of a large amount of (137)Cs deposition in eastern Japan was produced primarily by four events that occurred on March 12, 15-16, 20, and 21-23. The ratio of wet deposition to the total varied widely depending on the influence by the particular event. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. 福岛第一核电厂事故源项估算及方法比较%Fukushima Dai-ichi NPP Accident Source Term Estimation and Methods Comparison

    Institute of Scientific and Technical Information of China (English)

    王海洋; 王晓霞; 黄树明; 尤伟

    2011-01-01

    本文参考日本福岛第一核电厂的部分资料,利用美国核管会发布的《轻水堆核电厂事故源项》(NUREG-1465)以及国际原子能机构发布的《为轻水堆设计估算参考源项所提供的简化方法》(IAEA-TECDOC-1127)两份技术文件中的假设条件,分别计算出事故后由堆芯释放到安全壳内的放射性源项。同时通过对堆芯积存量、抑压水池净化因子等参数的估计,得出较为保守的环境释放源项。采用有关技术文件所提供的剂量计算模式及剂量转换因子对事故剂量后果做了估算,并比较、分析了两种假设条件下计算出的堆芯释放源项及其对事故剂量后果的影响。本文对核电厂发生严重事故时快速确定堆芯释放源项并估算事故剂量后果具有一定的参考意义。%This paper calculates the conservative radioactive source term released to the containment based on the assumptions specified in NUREG-1465 and IAEA-TECDOC-1127, using some of the available information of Fukushima Dai-ichi NPP. A series of environmental release source terms is obtained with the consideration of the parameters such as the cumulative amount of the radioactive material and the de- contamination factor in suppression pool. Moreover, this paper calculates the equivalent dose after accident using the models and parameters in some related technical documents. The containment radioactive relea- ses and the resultant doses, which are based on two assumptions mentioned above, are analyzed and com- pared. In conclusion, this paper does make sense for the quick establishment of the severe accident source term and the accident consequences estimation in nuclear power plant.

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

    Science.gov (United States)

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

    2015-01-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of cumulative

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

    Directory of Open Access Journals (Sweden)

    G. Katata

    2014-06-01

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

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

    Science.gov (United States)

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

    2014-06-01

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

  19. Long-term follow-up of radiation accident patients in Peru: review of two cases.

    Science.gov (United States)

    Barriga, L E; Zaharia, M; Pinillos, L; Moscol, A; Heredia, A; Sarria, G; Marquina, J; Barriga, O; Picon, C

    2012-10-01

    Overexposure to radioactive sources used in radiotherapy or industrial radiography may result in severe health consequences. This report assesses the initial clinical status and the medical and psychological long-term follow-up of two radiation accident patients from Peru during the mid-to-late 1990s: one patient exposed to a radiotherapy (60)Co source in Arequipa, the other patient to a (192)Ir source in Yanango. Commonalities and differences are described. The main causes in both accidents were human error and the failure to apply appropriate safety guidelines and standard operating procedures. Education and training of the personnel working with radiation sources are essential to prevent accidents. The experience gained from the medical management of the two patients is valuable for future treatment of such patients.

  20. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O`Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-12-31

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  1. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O' Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-01-01

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  2. Graphic console for analysis of severe accidents visualization of OEs, NAEs and calculation of the source term for the NPP-LV (CoGrAAS); Consola grafica para analisis de accidentes severos visualizacion de OEs, NAEs y calculo del termino fuente para la CLV (CoGrAAS)

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval V, S.; Mendoza E, P. R.; Gonzalez C, J. M.; Cecenas F, M. [Instituto Nacional de Electricidad y Energias Limpias, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Tijerina S, F., E-mail: francisco.tijerina@cfe.gob.mx [CFE, Central Nucleoelectrica Laguna Verde, Carretera Federal Cardel-Nautla Km 42.5, 91476 Municipio Alto Lucero, Veracruz (Mexico)

    2016-09-15

    In response to the Fukushima Daiichi nuclear power plant accident, the NRC conducted an analysis and issued recommendations to improve the safety of the nuclear reactors. These include strengthening and integrating emergency response capabilities and emphasizing periodic staff training, the performance of simulation exercises. As a tool to observe these recommendations, the Graphic Console was developed for Analysis of Severe Accidents, Visualization of OEs, NAEs and calculation of the source term for nuclear power plant of Laguna Verde (NPP-LV ; CoGrAAS). The CoGrAAS is a computer system that displays in an integrated, graphic and dynamic way the information of a catalog of previously simulated accident scenarios. Has core mimics, vessel, primary containment and safety systems, trend graph of thermodynamic and radiological variables and the emergency procedures (OEs), chronological list of events, windows with detailed information for the dry-well, among others. The use of CoGrAAS allows that staff to understand and become familiar with the thermo-hydraulic progression of actual scenarios that exceed the design basis including those with core damage as severe accidents. The system enables personnel to develop an integral vision of the scenarios during the exercises and drills by observing and analyzing the evolution of the main reactor, core and primary containment variables, the response of emergency systems and the influence of that progression on OEs and the emergency action levels (NAEs). The CoGrAAS allows o observe the radiological variables and obtain the source term, to make the projection of doses, at any time within the scenario evolution. Thus, not only can the phenomenology of severe accidents be analyzed and understood, it is also possible to exercise, verify and evaluate the performance of critical tasks in the application of procedures, guidelines and emergency management plans. (Author)

  3. MELCOR code source term characteristics for fast SBO scenario of OPR1000 plant

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok Jung; Kim, Tae Woon; Park, Sun Hee; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Off site consequence analysis in Level 3 PSA is mainly affected by source terms release characteristics of nuclear plant. The severe accidents analysis codes for quantifying the source terms release characteristics, such as MELCOR or MAAP, could be available to provide the detailed information of these characteristics to assess offsite consequence. To utilize these characteristics from severe accident analysis codes, MELCOR code was used in a specific severe accident scenario, i.e., fast station black out (SBO) for OPR1000 plant.

  4. Effects of source term characteristics on Off Site consequence

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok Jung; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Off site consequence analysis in Level 3 PSA is mainly affected by source term release characteristics of nuclear plant. The severe accident analysis codes for quantifying the source term release characteristics such as MELCOR and MAAP provide detailed information of these characteristics to assess the off site consequence. The aforementioned characteristics, however, have not been considered in the consequence analysis of domestic plants because of large uncertainty in these characteristics so far. Recently, the USNRC SOARCA report showed an approach to utilize detailed source term characteristics provided by MELCOR code to quantify the off site consequence more realistically. Main purpose of this study is to assess effects of the MELCOR source term characteristics on the off site consequence analysis of a domestic nuclear power plant, in a similar fashion to the SOARCA approach. Among many features characterizing source term, the most important one is to determine initial and boundary conditions of atmospheric dispersion such as:- Release amounts of source term - Release time and duration Moreover, plumes features (i.e., radiation clouds) affect atmospheric dispersion that shapes plume characteristics as follows: - Initial dimension of plumes - Plume rise - Deposition of radioactive materials during dispersion Although the current severe accident codes have some limitation in providing the entire source term release characteristics needed in the consequence analysis, the essential information for these features could be obtained from these codes. It is noted that the typical approaches, which generate source term information for the consequence analysis from the severe accident codes, should require a technical manipulation by the experts of consequence analysis. The present effort focused on an identification of insights to utilize source term characteristics of the severe accident codes.

  5. The latest results from source term research. Overview and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, Luis E. [Centro de Investigaciones Energeticas Medio Ambientales y Tecnologica (CIEMAT), Madrid (Spain); Haste, Tim [Centre d' Etudes de Cadarache, Paul-Lez-Durance (France). Institut de Radioprotection et de Surete Nucleaire (IRSN); Kaerkelae, Teemu [VTT Technical Research Centre of Finland Ltd, Espoo (Finland)

    2016-12-15

    Source term research has continued internationally for more than 30 years, increasing confidence in calculations of the potential radioactive release to the environment after a severe reactor accident. Important experimental data have been obtained, mainly under international frameworks such as OECD/NEA and EURATOM. Specifically, Phebus FP provides major insights into fission product release and transport. Results are included in severe accident analysis codes. Data from international projects are being interpreted with a view to further improvements in these codes. This paper synthesizes the recent main outcomes from source term research on these topics, and on source term mitigation. It highlights knowledge gaps remaining and discusses ways to proceed. Aside from this further knowledge-driven research, there is consensus on the need to assess the source term predictive ability of current system codes, taking account of scale-up from experiment to reactor conditions.

  6. In-Plant Fission Product Behavior in SGTR Accident with Long-Term SBO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Han, Seok Jung; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The off-site AC power was recovered in 9 days after the accident in the NPS. Therefore safety injection by fire pump truck with fresh water or seawater is only available in the Fukushima accident. However, safety injection by fire pump truck is not always effective due to the high pressure of RPV inside or leakages of alternative water injection flow paths. In the SBO situations in pressurized water reactor plant (PWR), turbine driven auxiliary feedwater (TD-AFW) pump can inject water to the secondary side of steam generator. However, turbine inlet steam flow control valve cannot work properly when loss of vital DC power occurs. Vital DC power is designed to be maintained during 4 or 8 hours in the SBO conditions. In this paper motor-driven and turbine driven AFW pumps are all assumed to be not working at time 0 sec as a worst case assumption. Iodine pool-scrubbing can occur in the secondary side of the faulted steam generator. However, iodine pool-scrubbing in the secondary side of the faulted steam generator is assumed not to be working, due to the assumption of the loss of DC battery for turbine inlet flow control valve. Iodine pool-scrubbing is one of the long-term research issues in safety assessment of nuclear power plant severe accident. PHEBUS FPT series and THAI experiment projects are typical projects on the resolving source term issues in severe accident of nuclear power plants. However, iodine retention by pool scrubbing is still a debating issue. In such containment bypass sequences, fission products can be released out to environment directly from RCS without retention or deposition in containment structures. SGTR is one of the hazardous accident scenarios in the typical PSA, because SGTR induces a large release amount of source term to environment directly. A key operation strategy was the isolation of the broken reactor coolant system loop from the intact loop. Typical core degradation in SGTR scenarios occurs with multiple failures of the isolation

  7. Modified ensemble Kalman filter for nuclear accident atmospheric dispersion: prediction improved and source estimated.

    Science.gov (United States)

    Zhang, X L; Su, G F; Yuan, H Y; Chen, J G; Huang, Q Y

    2014-09-15

    Atmospheric dispersion models play an important role in nuclear power plant accident management. A reliable estimation of radioactive material distribution in short range (about 50 km) is in urgent need for population sheltering and evacuation planning. However, the meteorological data and the source term which greatly influence the accuracy of the atmospheric dispersion models are usually poorly known at the early phase of the emergency. In this study, a modified ensemble Kalman filter data assimilation method in conjunction with a Lagrangian puff-model is proposed to simultaneously improve the model prediction and reconstruct the source terms for short range atmospheric dispersion using the off-site environmental monitoring data. Four main uncertainty parameters are considered: source release rate, plume rise height, wind speed and wind direction. Twin experiments show that the method effectively improves the predicted concentration distribution, and the temporal profiles of source release rate and plume rise height are also successfully reconstructed. Moreover, the time lag in the response of ensemble Kalman filter is shortened. The method proposed here can be a useful tool not only in the nuclear power plant accident emergency management but also in other similar situation where hazardous material is released into the atmosphere.

  8. Preliminary probabilistic design accident evaluation of the cold source facilities of the advanced neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, R.M.; Ramsey, C.T.

    1995-08-01

    Consistent with established Advanced Neutron Source (ANS) project policy for the use of probabilistic risk assessment (PRA) in design, a task has been established to use PRA techniques to help guide the design and safety analysis of the ANS cold sources. The work discussed in this report is the first formal output of the cold source PRA task. The major output at this stage is a list of design basis accidents, categorized into approximate frequency categories. This output is expected to focus attention on continued design work to define and optimize the design such that design basis accidents are better defined and have acceptable outcomes. Categorizing the design basis events (DBEs) into frequency categories should prove helpful because it will allow appropriate acceptance criteria to be applied. Because the design of the cold source is still proceeding, it is beyond the scope of this task to produce detailed event probability calculations or even, in some cases, detailed event sequence definitions. That work would take place as a logically planned follow-on task, to be completed as the design matures. Figure 1.1 illustrates the steps that would typically be followed in selecting design basis accidents with the help of PRA. Only those steps located above the dashed line on Fig. 1.1 are included in the scope of the present task. (Only an informal top-level failure modes and effects analysis was done.) With ANS project closeout expected in the near future, the scope of this task has been abbreviated somewhat beyond the state of available design information on the ANS cold sources, or what could be achieved in a reasonable time. This change was necessary to ensure completion before the closeout and because the in-depth analytical support necessary to define fully some of the accidents has already been curtailed.

  9. Definition of loss-of-coolant accident radiation source. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    1978-02-01

    Meaningful qualification testing of nuclear reactor components requires a knowledge of the radiation fields expected in a loss-of-coolant accident (LOCA). The overall objective of this program is to define the LOCA source terms and compare these with the output of various simulators employed for radiation qualification testing. The basis for comparison will be the energy deposition in a model reactor component. The results of the calculations are presented and some interpretation of the results given. The energy release rates and spectra were validated by comparison with other calculations using different codes since experimental data appropriate to these calculations do not exist.

  10. Inventory and source term evaluation of Russian nuclear power plants for marine applications

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, O. [Norwegian Radiation Protection Authority (Norway); Oelgaard, P.L. [Risoe National Lab. (Denmark)

    2006-04-15

    This report discusses inventory and source term properties in regard to operation and possible releases due to accidents from Russian marine reactor systems. The first part of the report discusses relevant accidents on the basis of both Russian and western sources. The overview shows that certain vessels were much more accident prone compared to others, in addition, there have been a noteworthy reduction in accidents the last two decades. However, during the last years new types of incidents, such as collisions, has occurred more frequently. The second part of the study considers in detail the most important factors for the source term; reactor operational characteristics and the radionuclide inventory. While Russian icebreakers has been operated on a similar basis as commercial power plants, the submarines has different power cyclograms which results in considerable lower values for fission product inventory. Theoretical values for radionuclide inventory are compared with computed results using the modelling tool HELIOS. Regarding inventory of transuranic elements, the results of the calculations are discussed in detail for selected vessels. Criticality accidents, loss-of-cooling accidents and sinking accidents are considered, bases on actual experiences with these types of accident and on theoretical considerations, and source terms for these accidents are discussed in the last chapter. (au)

  11. Particular Qualities of Soviet Information Policy according Chornobyl Accident: Source Study Aspects of the Problem

    Directory of Open Access Journals (Sweden)

    O. Makhno

    2016-07-01

    Full Text Available The article identifies the main groups of historical sources for a comprehensive study of Soviet information policy with respect to the Chernobyl accident. Determine their informational potential, deals with the methods of source analysis.

  12. Literature study of source term research for PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Sponton, L.L.; NiIsson, Lars

    2001-04-01

    A literature survey has been carried out in support of ongoing source term calculations with the MELCOR code of some severe accident scenarios for the Swedish Ringhals 2 pressurised water reactor (PWR). The research in the field of severe accidents in power reactors and the source term for subsequent release of radioisotopes was intensified after the Harrisburg accident and has produced a large amount of reports and papers. This survey was therefore limited to research concerning PWR type of reactors and with emphasis on papers related to MELCOR code development. A background is given, relating to some historic documents, and then more recent research after 1990 is reviewed. Of special interest is the ongoing PMbus-programme which is creating new and important results of benefit to the code development and validation of, among others, the MELCOR code. It is concluded that source term calculations involve simulation of many interacting complex physical phenomena, which result in large uncertainties The research has, however, over the years led to considerable improvements Thus has the uncertainty in source term predictions been reduced one to two orders of magnitude from the simpler codes in the early 1980-s to the more realistic codes of today, like MELCOR.

  13. An establishment of MELCOR code to generate source terms for off site consequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. H.; Han, S.; Ahn, K. I. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Since the Fukushima accident, an effective approach to a source term analysis for off site consequence analyses has been needed. The MELCOR code has the capability to assess the source term characteristics for this kind of demand. A comprehensive effort is required to use the MELCOR code for a source term analysis effectively. For this purpose, the following works are required: - Review and assess the MELCOR model relevant to source term characterization - Generate input files for source term analysis - Utilize the source term parameters This paper shows an effort to establish the MELCOR code to generate source terms for an off site consequence analysis.

  14. Review of SFR In-Vessel HCDA Source Terms

    Energy Technology Data Exchange (ETDEWEB)

    Suk, S. D.; Ha, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    An effort has been made in this study to search for and review the literatures on the studies of the phenomena related to the release of radionuclides and aerosols to the reactor containment of the sodium fast reactor (SFR) plants ( i.e., in-vessel source term. Review work is focused on the experimental programs to investigate the phenomena related to determining the source terms, with a brief review on supporting analytical models and computer programs. As a result of the severe accidents experienced at TMI and Chernobyl, much work has been done on the energetic CDA bubble source term (also called 'primary' or 'instantaneous' source term) defined as the amount of radioactive material released from the reactor vessel to the containment due to the rapid expansion of fuel or sodium leading to a failure of the vessel head. In this study, the research programs conducted to investigate the CDA (core disruptive accident) bubble behavior in the sodium pool for determining 'primary' or 'instantaneous' source term are introduced. The research programs to investigate the release and transport of fission products(FPs) and aerosols in the reactor containment (i.e., in-containment source term) are not described in this study.

  15. Scenarios catalog for the graphical console for analysis of severe accidents visualization of OEs, NAEs and calculation of source term of the NPP-LV; Catalogo de escenarios para la consola grafica para analisis de accidentes severos visualizacion de OEs, NAEs y calculo del termino fuente de la CLV

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval V, S. [Instituto Nacional de Electricidad y Energias Limpias, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Mendoza R, M. E.; Tijerina S, F.; Garcia C, T., E-mail: manuel.mendoza@cfe.gob.mx [CFE, Central Nucleoelectrica Laguna Verde, Carretera Federal Cardel-Nautla Km 42.5, 91476 Municipio Alto Lucero, Veracruz (Mexico)

    2016-09-15

    A nuclear power plant is operated at all times within the design criteria of structures, systems and components, and according to the operation technical specifications. For different areas of work of a nuclear power plant is necessary to carry out practices in which is useful to have the prediction of the thermo-hydraulic and radiological progression of scenarios that imply exceeding that design bases, even reaching the damage of the fuel in different degree. During the exercises and drills of the External Plan of Emergency Response, the projection of doses is done to exercise the different tasks of the plan. To make the projection of doses is required to have the radiological source term of the scenario on which is practiced. Because of this, was identified the convenience of having a catalog of scenarios for which the radiological source term was calculated. In 2004, a first version of the catalog was produced for a power of 2027 MW, and in 2011 the catalog was updated for extended power conditions, 2317 MW. Both versions were made using the severe accident simulator MAAP-3B. That catalog consists of a form and an optical storage device. The form contains tables and figures in which the characteristics of the scenario to be practiced are searched and the electronic files of the corresponding radiological source term are located in the storage device. Due to the recent development of the graphical console for analysis of severe accidents, visualization of OEs, NAEs and calculation of the source term for the nuclear power plant of Laguna Verde (NPP-LV) CoGrAAS, the catalog printed was replaced by an electronic catalog for the CoGrAAS. The new catalog retains the philosophy of the previous catalog, constituted by a wide collection of scenarios that involve different circumstances and phenomena, that can be used to practice different tasks during training exercises or simulacrums, and combined with the following advantages: the scenario selection is made from an

  16. Nuclear fuel cycle facility accident analysis handbook

    Energy Technology Data Exchange (ETDEWEB)

    Ayer, J E; Clark, A T; Loysen, P; Ballinger, M Y; Mishima, J; Owczarski, P C; Gregory, W S; Nichols, B D

    1988-05-01

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH.

  17. Estimated long term health effects of the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Cardis, E. [International Agency for Research on Cancer, Lyon (France)

    1996-07-01

    Apart from the dramatic increase in thyroid cancer in those exposed as children, there is no evidence to date of a major public health impact as a result of radiation exposure due to the Chernobyl accident in the three most affected countries (Belarus, Russia, and Ukraine). Although some increases in the frequency of cancer in exposed populations have been reported ,these results are difficult to interpret, mainly because of differences in the intensity and method of follow-up between exposed populations and the general population with which they are compared. If the experience of the survivors of the atomic bombing of Japan and of other exposed populations is applicable, the major radiological impact of the accident will be cases of cancer. The total lifetime numbers of excess cancers will be greatest among the `liquidators` (emergency and recovery workers) and among the residents of `contaminated` territories, of the order of 2000 to 2500 among each group (the size of the exposed populations is 200,000 liquidators and 3,700,000 residents of `contaminated` areas). These increases would be difficult to detect epidemiologically against an expected background number of 41500 and 433000 cases of cancer respectively among the two groups. The exposures for populations due to the Chernobyl accident are different in type and pattern from those of the survivors of the atomic bombing of Japan. Thus predictions derived from studies of these populations are uncertain. The extent of the incidence of thyroid cancer was not envisaged. Since only ten years have lapsed since the accident, continued monitoring of the health of the population is essential to assess the public health impact.

  18. Application of a new source term at Grand Gulf nuclear station

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, G.E.; Withrow, M.D. [Entergy Operations, Inc., Port Gibson, MS (United States)

    1997-12-01

    The NUREG and a number of companion regulatory guidance documents and methodologies establish new design basis accident source terms that individual existing BWR type reactor licensees may choose to adopt. These new source terms constitute the first major change in regulatory requirements.

  19. Traffic accidents in Belo Horizonte: the view from three different sources, 2008 to 2010.

    Science.gov (United States)

    Paixão, Lúcia Maria Miana Mattos; Gontijo, Eliane Dias; Drumond, Eliane de Freitas; Friche, Amélia Augusta de Lima; Caiaffa, Waleska Teixeira

    2015-01-01

    To analyze the contribution of three data sources in the description of traffic accidents in the city of Belo Horizonte, Brazil. Exploratory study of databases: BHTRANS (metropolitan traffic and transportation authority), Hospital Admissions and Mortality Information Systems, with estimation of proportions, coefficients and odds ratios. Incomplete data was observed in the three sources, especially regarding alcohol consumption by drivers and use of safety equipment. The victim profile among the sources was consistent: young adults, males, motorcycle riders and pedestrians. In addition to the high mortality rate (19.4 per 100.000 inhabitants), an increase in the number of non-fatal accidents was observed. An increase of 34% in hospital admissions and of 53% in hospital costs was evidenced. The motorcycle accident rate is higher than expected given the fleet composition. Male drivers have the highest risk of injury or death; relative to drivers, passengers or pedestrians have a 1,8 times higher risk of death. There was a 12% increase in the number of deaths at the site of the accident, 55% of which showed positive evidence of alcohol use and 50% higher risk of fatal accidents on weekends. Despite some incomplete record keeping and non-specific death registry codes, it was possible to characterize the main factors associated with accidents: elderly pedestrians, motorcycle riders, alcohol consumption and speeding. The study demonstrated the complementarity of the three data sources, with their different goals, and revealed important features of the traffic accident event-chain and victim profile, providing key data for the development of mitigation strategies.

  20. Source Term Analysis in Severe Accident Induced by Large Break Loss of Coolant Accident Coincident With Ship Blackout for Ship Reactor%船用堆大破口失水叠加全船断电严重事故源项分析

    Institute of Scientific and Technical Information of China (English)

    张彦招; 张帆; 赵新文; 郑映峰

    2013-01-01

    以某船用压水堆为研究对象,采用M ELCOR程序建立事故分析模型,研究大破口失水事故叠加全船断电严重事故下放射性裂变产物的行为,着重分析了惰性气体和CsI的释放、迁移、滞留特点及在堆舱内的分布。结果表明,83.12%惰性气体从堆芯释放出来,并主要存在于堆舱的气空间;83.08%的CsI从堆芯释放出来,其中,72.66%滞留在堆坑熔融物与一回路内,27.34%释放到堆舱内,并主要溶解于舱底水池中。本文分析结果可为舱室剂量评估、核应急管理提供依据。%Using MELCOR code ,the accident analysis model was established for a ship reactor .The behaviors of radioactive fission products were analyzed in the case of severe accident induced by large break loss of coolant accident coincident with ship blackout . The research mainly focused on the behaviors of release ,transport ,retention and the final distribution of inert gas and CsI . T he results show that 83.12% of inert gas releases from the core , and the most of inert gas exists in the containment . About 83.08% of CsI release from the core ,72.66% of w hich is detained in the debris and the primary system ,and 27.34% releases into the containment . The results can give a reference for the evaluation of cabin dose and nuclear emergency management .

  1. [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.

  2. SESAME: a software tool for the numerical dosimetric reconstruction of radiological accidents involving external sources and its application to the accident in Chile in December 2005.

    Science.gov (United States)

    Huet, C; Lemosquet, A; Clairand, I; Rioual, J B; Franck, D; de Carlan, L; Aubineau-Lanièce, I; Bottollier-Depois, J F

    2009-01-01

    Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. This dose distribution can be assessed by physical dosimetric reconstruction methods. Physical dosimetric reconstruction can be achieved using experimental or numerical techniques. This article presents the laboratory-developed SESAME--Simulation of External Source Accident with MEdical images--tool specific to dosimetric reconstruction of radiological accidents through numerical simulations which combine voxel geometry and the radiation-material interaction MCNP(X) Monte Carlo computer code. The experimental validation of the tool using a photon field and its application to a radiological accident in Chile in December 2005 are also described.

  3. The long-term problems of contaminated land: Sources, impacts and countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Baes, C.F. III

    1986-11-01

    This report examines the various sources of radiological land contamination; its extent; its impacts on man, agriculture, and the environment; countermeasures for mitigating exposures; radiological standards; alternatives for achieving land decontamination and cleanup; and possible alternatives for utilizing the land. The major potential sources of extensive long-term land contamination with radionuclides, in order of decreasing extent, are nuclear war, detonation of a single nuclear weapon (e.g., a terrorist act), serious reactor accidents, and nonfission nuclear weapons accidents that disperse the nuclear fuels (termed ''broken arrows'').

  4. HTGR Mechanistic Source Terms White Paper

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Moe

    2010-07-01

    The primary purposes of this white paper are: (1) to describe the proposed approach for developing event specific mechanistic source terms for HTGR design and licensing, (2) to describe the technology development programs required to validate the design methods used to predict these mechanistic source terms and (3) to obtain agreement from the NRC that, subject to appropriate validation through the technology development program, the approach for developing event specific mechanistic source terms is acceptable

  5. SOURCE TERMS FOR AVERAGE DOE SNF CANISTERS

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Goluoglu

    2000-06-09

    The objective of this calculation is to generate source terms for each type of Department of Energy (DOE) spent nuclear fuel (SNF) canister that may be disposed of at the potential repository at Yucca Mountain. The scope of this calculation is limited to generating source terms for average DOE SNF canisters, and is not intended to be used for subsequent calculations requiring bounding source terms. This calculation is to be used in future Performance Assessment calculations, or other shielding or thermal calculations requiring average source terms.

  6. Ablation Properties of the Carbon-Based Composites Used in Artificial Heat Source Under Fire Accident

    Institute of Scientific and Technical Information of China (English)

    TANG; Xian; HUANG; Jin-ming; ZHOU; Shao-jian; LUO; Zhi-fu

    2012-01-01

    <正>The ablation properties of the carbon-based composites used in artificial heat source under fire accident were investigated by the arc heater. In this work, we tested the carbon-based composites referring to Fig. 1. Their linear/mass ablation ratio and ablation morphologies were studied. The results showed that the carbon-based composites used in artificial heat source behaved well

  7. 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.

  8. Nuclear source term evaluation for launch accident environments

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, W.H.

    1996-05-01

    When United States space missions involve launching vehicles carrying significant quantities of nuclear material, US law requires that prior to launch the mission be approved by the Office of the President. This approval is to be based on an evaluation of the nuclear safety risks associated with the mission and the projected benefits. To assist in the technical evaluation of risks for each mission, an Interagency Nuclear Safety Review Panel (INSRP) is instituted to provide an independent assessment of the mission risks. INSRP`s assessment begins with a review of the safety analysis for the mission completed by the organization proposing the mission and documented in a Safety Analysis Report (SAR). In addition, INSRP may execute other analyses it deems necessary. Results are documented and passed to the decision maker in a Safety Evaluation Report (SER). The INSRP review and evaluation process has been described in some detail in a number of papers.

  9. Source terms: an investigation of uncertainties, magnitudes, and recommendations for research. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Levine, S.; Kaiser, G. D.; Arcieri, W. C.; Firstenberg, H.; Fulford, P. J.; Lam, P. S.; Ritzman, R. L.; Schmidt, E. R.

    1982-03-01

    The purpose of this document is to assess the state of knowledge and expert opinions that exist about fission product source terms from potential nuclear power plant accidents. This is so that recommendations can be made for research and analyses which have the potential to reduce the uncertainties in these estimated source terms and to derive improved methods for predicting their magnitudes. The main reasons for writing this report are to indicate the major uncertainties involved in defining realistic source terms that could arise from severe reactor accidents, to determine which factors would have the most significant impact on public risks and emergency planning, and to suggest research and analyses that could result in the reduction of these uncertainties. Source terms used in the conventional consequence calculations in the licensing process are not explicitly addressed.

  10. Source terms: an investigation of uncertainties, magnitudes, and recommendations for research. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Levine, S.; Kaiser, G. D.; Arcieri, W. C.; Firstenberg, H.; Fulford, P. J.; Lam, P. S.; Ritzman, R. L.; Schmidt, E. R.

    1982-03-01

    The purpose of this document is to assess the state of knowledge and expert opinions that exist about fission product source terms from potential nuclear power plant accidents. This is so that recommendations can be made for research and analyses which have the potential to reduce the uncertainties in these estimated source terms and to derive improved methods for predicting their magnitudes. The main reasons for writing this report are to indicate the major uncertainties involved in defining realistic source terms that could arise from severe reactor accidents, to determine which factors would have the most significant impact on public risks and emergency planning, and to suggest research and analyses that could result in the reduction of these uncertainties. Source terms used in the conventional consequence calculations in the licensing process are not explicitly addressed.

  11. 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

  12. Source contributions to radiocesium contaminated particulate matter deposited in a reservoir after the Fukushima accident

    Science.gov (United States)

    Laceby, J. Patrick; Huon, Sylvain; Hayashi, Seiji; Onda, Yuichi; Evrard, Olivier

    2017-04-01

    The Fukushima nuclear accident resulted in the deposition of radiocesium over forested and rural landscapes northwest of the power plant. Although there have been several investigations into the dynamics of contaminated river sediment, less attention has been paid to the sources of deposited particulate matter in dams and reservoirs. In the Fukushima Prefecture, there are 10 significant dams and over a 1,000 reservoirs for both agricultural and surface water management. These reservoirs may have trapped a significant volume of radiocesium contaminated sediment, and understanding the sources of this material is important for the ongoing management of contamination in the region. Accordingly, the source of contaminated particulate matter (i.e. cultivated, forest and subsoils) deposited in the Mano Dam reservoir, Japan, was investigated with the analyses and modelling of carbon and nitrogen stable isotope ratios, total organic carbon and total nitrogen concentrations. Four sediment cores with lengths ranging from 29-41 cm were sampled in the Mano Dam, approximately 40 km northwest of the FDNPP. Source samples were taken from 46 forest soils, 28 cultivated soils and 25 subsoils in the region. Carbon-nitrogen parameters were analysed on all samples and a concentration-dependent distribution modelling approach was used to apportion source contributions. Three of the four cores sampled in the Mano Dam reservoir had distinct radiocesium peaks representative of the initial post-accident wash-off phase. Cultivated sources were responsible for 48% (SD 7%) of the deposited fine particulate matter in the three cores with the radiocesium peaks, whereas forests were modelled to contribute 27% (SD 6%) and subsoil sources 25% (SD 4%). Ongoing decontamination of cultivated sources in the Fukushima region should result in a decrease of contaminated matter deposited in reservoirs. More research is required to understand the potential ongoing source contributions from forested

  13. Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Alfheim, P. [Scandpower AB, Sundbyberg (Sweden)

    2012-09-15

    The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

  14. Using Bayesian Belief Network (BBN) modelling for rapid source term prediction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Dedda, F.D.; Hansson, F.; Sjoekvist, S.; Sunnegaerd, K. [Lloyd' s Register Consulting AB, Sundbyberg (Sweden)

    2013-10-15

    The project presented in this report deals with a number of complex issues related to the development of a tool for rapid source term prediction (RASTEP), based on a plant model represented as a Bayesian belief network (BBN) and a source term module which is used for assigning relevant source terms to BBN end states. Thus, RASTEP uses a BBN to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, composition, timing, and release path of released radio-nuclides). The output is a set of possible source terms with associated probabilities. One major issue has been associated with the integration of probabilistic and deterministic analyses are addressed, dealing with the challenge of making the source term determination flexible enough to give reliable and valid output throughout the accident scenario. The potential for connecting RASTEP to a fast running source term prediction code has been explored, as well as alternative ways of improving the deterministic connections of the tool. As part of the investigation, a comparison of two deterministic severe accident analysis codes has been performed. A second important task has been to develop a general method where experts' beliefs can be included in a systematic way when defining the conditional probability tables (CPTs) in the BBN. The proposed method includes expert judgement in a systematic way when defining the CPTs of a BBN. Using this iterative method results in a reliable BBN even though expert judgements, with their associated uncertainties, have been used. It also simplifies verification and validation of the considerable amounts of quantitative data included in a BBN. (Author)

  15. Workshop on short-term health effects of reactor accidents: Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    1986-08-08

    The high-dose early-effects research that has been continued has been done in the context of infrequent accidents with large radiation sources and the use of bone marrow transfusions for treating malignancies, especially leukemia. It thus seemed appropriate to bring together those who have done research on and have had experience with massive whole-body radiation. The objectives were to review what is known about the acute effects of whole-body irradiation, to review the current knowledge of therapy, and particularly of the diagnostic and immunologic problems encountered in bone marrow therapy, and to compare this knowledge with observations made to date on the Chernobyl accident radiation casualties. Dr. Robert Gale, who had helped to care for these casualties, was present at the Workshop. It was hoped that such a review would help those making continuing clinical and pathological observations on the Chernobyl casualties, and that these observations would provide a basis for recommendations for additional research that might result in improved ability to manage successfully this type of severe injury.

  16. BWR Source Term Generation and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    J.C. Ryman

    2003-07-31

    This calculation is a revision of a previous calculation (Ref. 7.5) that bears the same title and has the document identifier BBAC00000-01717-0210-00006 REV 01. The purpose of this revision is to remove TBV (to-be-verified) -41 10 associated with the output files of the previous version (Ref. 7.30). The purpose of this and the previous calculation is to generate source terms for a representative boiling water reactor (BWR) spent nuclear fuel (SNF) assembly for the first one million years after the SNF is discharged from the reactors. This calculation includes an examination of several ways to represent BWR assemblies and operating conditions in SAS2H in order to quantify the effects these representations may have on source terms. These source terms provide information characterizing the neutron and gamma spectra in particles per second, the decay heat in watts, and radionuclide inventories in curies. Source terms are generated for a range of burnups and enrichments (see Table 2) that are representative of the waste stream and stainless steel (SS) clad assemblies. During this revision, it was determined that the burnups used for the computer runs of the previous revision were actually about 1.7% less than the stated, or nominal, burnups. See Section 6.6 for a discussion of how to account for this effect before using any source terms from this calculation. The source term due to the activation of corrosion products deposited on the surfaces of the assembly from the coolant is also calculated. The results of this calculation support many areas of the Monitored Geologic Repository (MGR), which include thermal evaluation, radiation dose determination, radiological safety analyses, surface and subsurface facility designs, and total system performance assessment. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Disposal Container (Ref. 7.27, page 7). Therefore, this calculation is subject to the requirements of the

  17. IMPACTS OF SOURCE TERM HETEROGENEITIES ON WATER PATHWAY DOSE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.; GUSKOV, A.; POSKAS, P.; RUPERTI, N.; HANUSIK, V.; ET AL.

    2004-09-15

    specific activities and small physical sizes and for which a solution has to be found in term of long-term disposal. Together with their casing and packaging, they are one form of heterogeneous waste; many other forms of waste with heterogeneous properties exist. They may arise in very small quantities and with very specific characteristics in the case of small producers, or in larger streams with standard characteristics in others. This wide variety of waste induces three main different levels of waste heterogeneity: (1) hot spot (e.g. disused sealed sources); (2) large item inside a package (e.g. metal components); and (3) very large items to be disposed of directly in the disposal unit (e.g. irradiated pipes, vessels). Safety assessments generally assume a certain level of waste homogeneity in most of the existing or proposed disposal facilities. There is a need to evaluate the appropriateness of such an assumption and the influence on the results of safety assessment. This need is especially acute in the case of sealed sources. There are many cases where are storage conditions are poor, or there is improper management leading to a radiological accident, some with significant or detrimental impacts. Disposal in a near surface disposal facility has been used in the past for some disused sealed sources. This option is currently in use for others sealed sources, or is being studied for the rest of them. The regulatory framework differs greatly between countries. In some countries, large quantities of disused sealed sources have been disposed of without any restriction, in others their disposal is forbidden by law. In any case, evaluation of the acceptability of disposal of disused sealed sources in near surface disposal facility is of utmost importance.

  18. 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.).

  19. Long-Term Station Blackout Accident Analyses of a PWR with RELAP5/MOD3.3

    Directory of Open Access Journals (Sweden)

    Andrej Prošek

    2013-01-01

    Full Text Available Stress tests performed in Europe after accident at Fukushima Daiichi also required evaluation of the consequences of loss of safety functions due to station blackout (SBO. Long-term SBO in a pressurized water reactor (PWR leads to severe accident sequences, assuming that existing plant means (systems, equipment, and procedures are used for accident mitigation. Therefore the main objective was to study the accident management strategies for SBO scenarios (with different reactor coolant pumps (RCPs leaks assumed to delay the time before core uncovers and significantly heats up. The most important strategies assumed were primary side depressurization and additional makeup water to reactor coolant system (RCS. For simulations of long term SBO scenarios, including early stages of severe accident sequences, the best estimate RELAP5/MOD3.3 and the verified input model of Krško two-loop PWR were used. The results suggest that for the expected magnitude of RCPs seal leak, the core uncovery during the first seven days could be prevented by using the turbine-driven auxiliary feedwater pump and manually depressurizing the RCS through the secondary side. For larger RCPs seal leaks, in general this is not the case. Nevertheless, the core uncovery can be significantly delayed by increasing RCS depressurization.

  20. Development of alternate methods of determining integrated SMR source terms

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Kenneth [Electric Power Research Inst. (EPRI), Charlotte, NC (United States)

    2014-06-10

    The Nuclear Energy Institute (NEI) Small Modular Reactor (SMR) Licensing Task Force (TF) has been evaluating licensing issues unique and important to iPWRs, ranking these issues, and developing NEI position papers for submittal to the U.S. Nuclear Regulatory Commission (NRC) during the past three years. Papers have been developed and submitted to the NRC in a range of areas including: Price-Anderson Act, NRC annual fees, security, modularity, and staffing. In December, 2012, NEI completed a draft position paper on SMR source terms and participated in an NRC public meeting presenting a summary of this paper, which was subsequently submitted to the NRC. One important conclusion of the source term paper was the evaluation and selection of high importance areas where additional research would have a significant impact on source terms. The highest ranked research area was iPWR containment aerosol natural deposition. The NRC accepts the use of existing aerosol deposition correlations in Regulatory Guide 1.183, but these were developed for large light water reactor (LWR) containments. Application of these correlations to an iPWR design has resulted in greater than a ten-fold reduction of containment airborne aerosol inventory as compared to large LWRs. Development and experimental justification of containment aerosol natural deposition correlations specifically for the unique iPWR containments is expected to result in a large reduction of design basis and beyond-design-basis accident source terms with concomitantly smaller dose to workers and the public. Therefore, NRC acceptance of iPWR containment aerosol natural deposition correlations will directly support the industry’s goal of reducing the Emergency Planning Zone (EPZ) for SMRs. Based on the results in this work, it is clear that thermophoresis is relatively unimportant for iPWRs. Gravitational settling is well understood, and may be the dominant process for a dry environment. Diffusiophoresis and enhanced

  1. A Perspective on Long-Term Recovery Following the Fukushima Nuclear Accident - 12075

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.Y. [Environmental Science Division, Argonne National Laboratory, Argonne, IL (United States)

    2012-07-01

    The tragic events at the Fukushima Daiichi Nuclear Power Station began occurring on March 11, 2011, following Japan's unprecedented earthquake and tsunami. The subsequent loss of external power and on-site cooling capacity severely compromised the plant's safety systems, and subsequently, led to core melt in the affected reactors and damage to spent nuclear fuel in the storage pools. Together with hydrogen explosions, this resulted in a substantial release of radioactive material to the environment (mostly Iodine-131 and Cesium- 137), prompting an extensive evacuation effort. The latest release estimate places the event at the highest severity level (Level 7) on the International Nuclear Event Scale, the same as the Chernobyl accident of 1986. As the utility owner endeavored to stabilize the damaged facility, environmental contamination continued to propagate and affect every aspect of daily life in the affected region of Japan. Elevated levels of radioactivity (mostly dominated by Cs-137 with the passage of time) were found in soil, drinking water, vegetation, produce, seafood, and other foodstuffs. An estimated 80,000 to 90,000 people were evacuated; more evacuations are being contemplated months after the accident, and a vast amount of land has become contaminated. Early actions were taken to ban the shipment and sale of contaminated food and drinking water, followed by later actions to ban the shipment and sale of contaminated beef, mushrooms, and seafood. As the event continues to evolve toward stabilization, the long-term recovery effort needs to commence - a process that doubtless will involve rather complex decision-making interactions between various stakeholders. Key issues that may be encountered and considered in such a process include (1) socio-political factors, (2) local economic considerations, (3) land use options, (4) remediation approaches, (5) decontamination methods, (6) radioactive waste management, (7) cleanup levels and options

  2. Long-term aging and loss-of-coolant accident (LOCA) testing of electrical cables

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, C.F.; Gauthier, G.; Carlin, F. [and others

    1996-10-01

    Experiments were performed to assess the aging degradation and loss-of-coolant accident (LOCA) behavior of electrical cables subjected to long-term aging exposures. Four different cable types were tested in both the U.S. and France: (1) U.S. 2 conductor with ethylene propylene rubber (EPR) insulation and a Hypalon jacket. (2) U.S. 3 conductor with cross-linked polyethylene (XLPE) insulation and a Hypalon jacket. (3) French 3 conductor with EPR insulation and a Hypalon jacket. (4) French coaxial with polyethylene (PE) insulation and a PE jacket. The data represent up to 5 years of simultaneous aging where the cables were exposed to identical aging radiation doses at either 40{degrees}C or 70{degrees}C; however, the dose rate used for the aging irradiation was varied over a wide range (2-100 Gy/hr). Aging was followed by exposure to simulated French LOCA conditions. Several mechanical, electrical, and physical-chemical condition monitoring techniques were used to investigate the degradation behavior of the cables. All the cables, except for the French PE cable, performed acceptably during the aging and LOCA simulations. In general, cable degradation at a given dose was highest for the lowest dose rate, and the amount of degradation decreased as the dose rate was increased.

  3. Risk comparisons based on representative source terms with the NUREG-1150 results

    Energy Technology Data Exchange (ETDEWEB)

    Mubayi, V.; Davis, R.E.; Hanson, A.L.

    1993-12-01

    Standardized source terms, based on a specified release of fission products during potential accidents at commercial light water nuclear reactors, have been used for a long time for regulatory purposes. The siting of nuclear power plants, for example, which is governed by Part 100 of the Code of Federal Regulations Title 10, has utilized the source term recommended in TID-14844 supplemented by Regulatory Guides 1.3 and 1.4 and the Standard Review Plan. With the introduction of probabilistic risk assessment (PRA) methods, the source terms became characterized not only by the amount of fission products released, but also by the probability of the release. In the Reactor Safety Study, for example, several categories of source terms, characterized by release severity and probability, were developed for both pressurized and boiling water reactors (PWRs and BWRs). These categories were based on an understanding of the likely paths and associated phenomenology of accident progression following core damage to possible failure of the containment and release to the environment.

  4. TRIGA MARK-II source term

    Science.gov (United States)

    Usang, M. D.; Hamzah, N. S.; J. B., Abi M.; M. Z., M. Rawi; Abu, M. P.

    2014-02-01

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  5. TRIGA MARK-II source term

    Energy Technology Data Exchange (ETDEWEB)

    Usang, M. D., E-mail: mark-dennis@nuclearmalaysia.gov.my; Hamzah, N. S., E-mail: mark-dennis@nuclearmalaysia.gov.my; Abi, M. J. B., E-mail: mark-dennis@nuclearmalaysia.gov.my; Rawi, M. Z. M. Rawi, E-mail: mark-dennis@nuclearmalaysia.gov.my; Abu, M. P., E-mail: mark-dennis@nuclearmalaysia.gov.my [Bahagian Teknologi Reaktor, Agensi Nuklear Malaysia, 43000 Kajang (Malaysia)

    2014-02-12

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  6. Analysis of safety information for nuclear power plants and development of source term estimation program

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Choi, Seong Soo; Park, Jin Hee [Atomic Creative Technology, Taejon (Korea, Republic of)

    1999-12-15

    Current CARE(Computerized Advisory System for Radiological Emergency) in KINS(Korea Institute of Nuclear Safety) has no STES(Source Term Estimation System) which links between SIDS(Safety Information Display System) and FADAS(Following Accident Dose Assessment System). So in this study, STES is under development. STES system is the system that estimates the source term based on the safety information provided by SIDS. Estimated source term is given to FADAS as an input for estimation of environmental effect of radiation. Through this first year project STES for the Kori 3,4 and Younggwang 1,2 has been developed. Since there is no CARE for Wolsong(PHWR) plants yet, CARE for Wolsong is under construction. The safety parameters are selected and the safety information display screens and the alarm logic for plant status change are developed for Wolsong Unit 2 based on the design documents for CANDU plants.

  7. Review of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O' Kula, K.R.; Hunter, C.H.

    1992-01-01

    The purpose of this work was to verify the Source Term Setup Module of the Reactor Accident Program (RAP) which is used to perform environmental consequence assessments during emergency response situations at the Savannah River Site (SRS). The Source Term Setup Module is that portion of the program that estimates the source term based on either an input number of melted assemblies or a derived number of melted assemblies based on the Total Stack Activity Monitor (TSAM) response. In order to verify the code, the following items were completed: a review of isotope and fuel specific data by examining the original literature, a complete derivation of all equations employed in the module, and a comparison study of hand calculations with computer results.

  8. Review of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O`Kula, K.R.; Hunter, C.H.

    1992-12-31

    The purpose of this work was to verify the Source Term Setup Module of the Reactor Accident Program (RAP) which is used to perform environmental consequence assessments during emergency response situations at the Savannah River Site (SRS). The Source Term Setup Module is that portion of the program that estimates the source term based on either an input number of melted assemblies or a derived number of melted assemblies based on the Total Stack Activity Monitor (TSAM) response. In order to verify the code, the following items were completed: a review of isotope and fuel specific data by examining the original literature, a complete derivation of all equations employed in the module, and a comparison study of hand calculations with computer results.

  9. Advanced Neutron Source Reactor (ANSR) phenomena identification and ranking (PIR) for large break loss of coolant accidents (LBLOCA)

    Energy Technology Data Exchange (ETDEWEB)

    Ruggles, A. E. [Oak Ridge National Lab., TN (United States); Tennessee Univ., Knoxville, TN (United States); Cheng, L. Y. [Brookhaven National Lab., Upton, NY (United States); Dimenna, R. A. [Westinghouse Savannah River Co., Aiken, SC (United States); Griffith, P. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Wilson, G. E. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-06-01

    A team of experts in reactor analysis conducted a phenomena identification and ranking (PIR) exercise for a large break loss-of-coolant accident (LBLOCA) in the Advanced Neutron source Reactor (ANSR). The LBLOCA transient is broken into two separate parts for the PIR exercise. The first part considers the initial depressurization of the system that follows the opening of the break. The second part of the transient includes long-term decay heat removal after the reactor is shut down and the system is depressurized. A PIR is developed for each part of the LBLOCA. The ranking results are reviewed to establish if models in the RELAP5-MOD3 thermalhydraulic code are adequate for use in ANSR LBLOCA simulations. Deficiencies in the RELAP5-MOD3 code are identified and existing data or models are recommended to improve the code for this application. Experiments were also suggested to establish models for situations judged to be beyond current knowledge. The applicability of the ANSR PIR results is reviewed for the entire set of transients important to the ANSR safety analysis.

  10. Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

    Science.gov (United States)

    Lujanienė, G.; Valiulis, D.; Byčenkienė, S.; Šakalys, J.; Povinec, P. P.

    2012-12-01

    137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994-2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March-April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

  11. Long-term transport and dispersion of 137Cs released into ocean off Fukushima nuclear accident

    Science.gov (United States)

    Zhao, Chang; Qiao, Fangli; Wang, Guansuo; Xia, Changshui; Jung, KyungTae

    2014-05-01

    In the following days after the Fukushima nuclear accident which happened in 11th March 2011, significant amounts of radioactive materials (131I, 134Cs and 137Cs) had been leaking into the terrestrial and marine environments. The radionuclides model was used to study the distribution of the 137Cs in the Pacific and the Indian Ocean released from the Fukushima accident. The simulation on the distribution of 137Cs agrees well with the the observed profiles in the 9th November 2011, which proved the validaty of the model. In the first year of our model run, the 137Cs is carried eastward by the Kuroshio and its extension, spreading southward and northword meanwhile. Four or five years after the accident, the 137Cs reaches the US coast with the surface waters of the Pacific Ocean; its concentration is no higher than 3 Bq/m3. Ten years after the accident, all the North Pacific Ocean is labeled with the 137Cs from the Fukushima. The concentration is less than 1 Bq/m3 at that time. Thirty years after the accident, the concentration of 137Cs in both the Pacific and the Indian Ocean is below 0.1 Bq/m3. Since the spreading path of 137Cs from the Fukushima nuclear accident is just the migration route of the Pacific tuna, a kind of fish inhabit the western and eastern North Pacific, it may cause radioactive contamination to the fish. In the offshore seas of China, the 137Cs from Fukushima nuclear accident is very low (<0.2 Bq/m3) .

  12. Analyses of containment source term of BWR5 considering iodine chemistry suppression pool with THALES-2 code

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Jun; Moriyama, Kiyofumi [Japan Atomic Energy Agency, Ibaraki (Japan)

    2009-05-15

    After JCO criticality accident in 1999, recognized the importance of PSA application research for emergency planning and basic technical study supporting decision making in protective actions. In order to evaluate containment source term in the late phase SA, coupling of severe accident analysis code THALES-2 and kinetics of iodine chemistry code Kiche was done. And containment source term analyses were performed a typical accident sequence TQUV of BWR5/Mark-II. The lower the pH in the pool was, the more fraction of iodine were released to gas phase, as was in agreement with the known tendency. Total release fractions of all iodine species to gas phase at 40 hr were 0.1[-](pH=5), 0.01[-](pH=7), 4x10{sup -4}[-] (pH=9). I{sub 2} was dominant in released iodine to gas phase and most of released I{sub 2} was adsorbed to the wall. As the operation of the containment spray, the release of iodine tot the gas phase was enhanced due to the break of a steady state by the circulation in the containment. In future, JAEA will perform containment source term analyses for extensive accident sequences with consideration of iodine chemistry.

  13. 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.)

  14. Literature review on metallic fuel source term for sodium cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Nam Duk; Bae, Moo Hoon; Shin, An Dong; Huh, Chang Wook [Korea Institute of Nuclear Safety, Daejon (Korea, Republic of)

    2012-10-15

    Source term is defined as the release of radionuclides from the fuel and coolant into the containment, and subsequently to the environment, following a severe accident where a significant portion of the reactor core has melted. Of the many issues associated with the development and deployment of SFRs, one of high regulatory importance is the source term to be used in the siting of the reactor. Apart from assessing the radiological consequences for siting, it is also important for designing filtering systems and even reactor components. Overly conservative source term for light water reactor, TID 14844 demands for very fast closure of main steam isolation valves, rapid startup of emergency diesels, and safety systems designed to mitigate gaseous iodine. In spite of this importance, most of the knowledge we have for SFR source term comes from the research performed before 1980s. Moreover, majority of the work on metallic fuels was done during the late 1950's through the 1960's. This paper reviews and summarizes the main characteristics of SFR source terms based on the available literatures.

  15. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  16. MIGRATORY GAME BIRDS AS A SOURCE OF PUBLIC EXPOSURE FROM THE FUKUSHIMA NUCLEAR POWER PLANT ACCIDENT

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2011-01-01

    Full Text Available This article examines assessments of the impact of the Fukushima nuclear power plant accident on exposure of the Russian Federation population related to the seasonal migration of game birds. Intake of artificial radionuclides with meat of migratory game birds is shown to be one of the major pathways for the population exposure in the Far Eastern region of the country.

  17. Information Sources as Explanatory Variables for the Belgian Health-Related Risk Perception of the Fukushima Nuclear Accident.

    Science.gov (United States)

    Vyncke, Bart; Perko, Tanja; Van Gorp, Baldwin

    2016-06-20

    The media play an important role in risk communication, providing information about accidents, both nearby and far away. Each media source has its own presentation style, which could influence how the audience perceives the presented risk. This study investigates the explanatory power of 12 information sources (traditional media, new media, social media, and interpersonal communication) for the perceived risk posed by radiation released from the damaged Fukushima nuclear power plant on respondents' own health and that of the population in general. The analysis controlled for attitude toward nuclear energy, gender, education, satisfaction with the media coverage, and duration of attention paid to the coverage. The study uses a large empirical data set from a public opinion survey, which is representative for the Belgian population with respect to six sociodemographic variables. Results show that three information sources are significant regressors of perceived health-related risk of the nuclear accident: television, interpersonal communication, and the category of miscellaneous online sources. More favorable attitudes toward nuclear power, longer attention to the coverage, and higher satisfaction with the provided information lead to lower risk perception. Taken together, the results suggest that the media can indeed have a modest influence on how the audience perceives a risk.

  18. Guide to Sources: Term Paper Strategy.

    Science.gov (United States)

    White, Lucinda M.

    This two-page guide suggests an eight-step term paper research strategy for students using the Fogler Library at the University of Maine. The student is first guided to encyclopedias for overview articles with bibliographies, then directed to the card catalog; periodical indexes; and indexes for books, journal articles, and newspaper articles.…

  19. Source dynamics of radiocesium-contaminated particulate matter deposited in an agricultural water reservoir after the Fukushima nuclear accident.

    Science.gov (United States)

    Huon, Sylvain; Hayashi, Seiji; Laceby, J Patrick; Tsuji, Hideki; Onda, Yuichi; Evrard, Olivier

    2017-09-06

    The Fukushima nuclear accident in Japan resulted in the deposition of radiocesium over forested and rural landscapes northwest of the power plant. Although there have been several investigations into the dynamics of contaminated river sediment, less attention has been paid to the sources of deposited particulate matter in dams and reservoirs. In the Fukushima Prefecture, there are 10 significant dams and over a 1000 reservoirs for both agricultural and surface water management. These reservoirs may have trapped a significant volume of radiocesium-contaminated sediment. Therefore, characterizing the sources of contaminated particulate matter is important for the ongoing management of contamination in the region. Accordingly, the composition of particulate matter deposited in the Mano Dam reservoir, approximately 40km northwest of the power plant, was investigated with the analyses and modelling of carbon and nitrogen stable isotope ratios (δ(13)C and δ(15)N), total organic carbon (TOC) and total nitrogen (TN) concentrations. Four sediment cores, with lengths ranging 29-41cm, were sampled in the Mano Dam. Source samples from 46 forest soils, 28 cultivated soils and 25 subsoils were used to determine the source contributions of particulate matter. Carbon and nitrogen parameters were analyzed on all samples and a concentration-dependent distribution modelling approach was used to apportion source contributions. Three of the four cores sampled in the Mano Dam reservoir had distinct radiocesium peaks representative of the initial post-accident wash-off phase. Cultivated sources were responsible for 48±7% of the deposited fine particulate matter whereas forests were modelled to contribute 27±6% and subsoil sources 25±4%. Ongoing decontamination of cultivated sources in the Fukushima region should result in a decrease of contaminated matter deposition in reservoirs. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Evaluation of long-term post-accident core cooling of Three Mile Island Unit 2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-15

    On the basis of current understanding of the accident scenario and available data, the staff reports here on its evaluation of the condition of the core and the core flow resistance as it might affect ability to cool the core by natural circulation. The natural circulation cooling capability of TMI-2 for the estimated core flow resistance and a variety of other conditions is evaluated and a comparison of the Base Case and off-nominal plant configurations is presented. The potential for and effects of natural convection core cooling are addressed, and the staff recommendations for reactor performance acceptance criteria upon initiation of natural convection are presented.

  1. Maximal design basis accident of fusion neutron source DEMO-TIN

    Energy Technology Data Exchange (ETDEWEB)

    Kolbasov, B. N., E-mail: Kolbasov-BN@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)

    2015-12-15

    When analyzing the safety of nuclear (including fusion) facilities, the maximal design basis accident at which the largest release of activity is expected must certainly be considered. Such an accident is usually the failure of cooling systems of the most thermally stressed components of a reactor (for a fusion facility, it is the divertor or the first wall). The analysis of safety of the ITER reactor and fusion power facilities (including hybrid fission–fusion facilities) shows that the initial event of such a design basis accident is a large-scale break of a pipe in the cooling system of divertor or the first wall outside the vacuum vessel of the facility. The greatest concern is caused by the possibility of hydrogen formation and the inrush of air into the vacuum chamber (VC) with the formation of a detonating mixture and a subsequent detonation explosion. To prevent such an explosion, the emergency forced termination of the fusion reaction, the mounting of shutoff valves in the cooling systems of the divertor and the first wall or blanket for reducing to a minimum the amount of water and air rushing into the VC, the injection of nitrogen or inert gas into the VC for decreasing the hydrogen and oxygen concentration, and other measures are recommended. Owing to a continuous feed-out of the molten-salt fuel mixture from the DEMO-TIN blanket with the removal period of 10 days, the radioactivity release at the accident will mainly be determined by tritium (up to 360 PBq). The activity of fission products in the facility will be up to 50 PBq.

  2. Environmental radiation safety source term evaluation program

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Filipy, R.E.; Cannon, W.C.; Craig, D.K.

    1977-04-01

    Plutonium-238 is currently used in the form of a pure refractory oxide as a power source on a number of space vehicles that have already been or will be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere and impact with the earth's surface without releasing any plutonium, the possibility of such an event can never be absolutely excluded. Three separate tasks were undertaken in this study. The interactions between soils and /sup 238/PuO/sub 2/ aerosols which might be created in a space launch about environment were examined. Aging of the plutonium-soil mixture under a humid atmosphere showed a trend toward the slow coagulation of two dilute aerosols. Studies on marine animals were conducted to assess the response of /sup 238/PuO/sub 2/ pellets to conditions found 60 feet below the ocean surface. Ultrafilterability studies measured the solubility of /sup 238/PuO/sub 2/ as a function of time, temperature, suspension concentration and molality of solvent. (ACR)

  3. Source term derivation and radiological safety analysis for the TRICO II research reactor in Kinshasa

    Energy Technology Data Exchange (ETDEWEB)

    Muswema, J.L., E-mail: jeremie.muswem@unikin.ac.cd [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Ekoko, G.B. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Lukanda, V.M. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Democratic Republic of the Congo' s General Atomic Energy Commission, P.O. Box AE1 (Congo, The Democratic Republic of the); Lobo, J.K.-K. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Darko, E.O. [Radiation Protection Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Boafo, E.K. [University of Ontario Institute of Technology, 2000 Simcoe St. North, Oshawa, ONL1 H7K4 (Canada)

    2015-01-15

    Highlights: • Atmospheric dispersion modeling for two credible accidents of the TRIGA Mark II research reactor in Kinshasa (TRICO II) was performed. • Radiological safety analysis after the postulated initiating events (PIE) was also carried out. • The Karlsruhe KORIGEN and the HotSpot Health Physics codes were used to achieve the objectives of this study. • All the values of effective dose obtained following the accident scenarios were below the regulatory limits for reactor staff members and the public, respectively. - Abstract: The source term from the 1 MW TRIGA Mark II research reactor core of the Democratic Republic of the Congo was derived in this study. An atmospheric dispersion modeling followed by radiation dose calculation were performed based on two possible postulated accident scenarios. This derivation was made from an inventory of peak radioisotope activities released in the core by using the Karlsruhe version of isotope generation code KORIGEN. The atmospheric dispersion modeling was performed with HotSpot code, and its application yielded to radiation dose profile around the site using meteorological parameters specific to the area under study. The two accident scenarios were picked from possible accident analyses for TRIGA and TRIGA-fueled reactors, involving the case of destruction of the fuel element with highest activity release and a plane crash on the reactor building as the worst case scenario. Deterministic effects of these scenarios are used to update the Safety Analysis Report (SAR) of the reactor, and for its current version, these scenarios are not yet incorporated. Site-specific meteorological conditions were collected from two meteorological stations: one installed within the Atomic Energy Commission and another at the National Meteorological Agency (METTELSAT), which is not far from the site. Results show that in both accident scenarios, radiation doses remain within the limits, far below the recommended maximum effective

  4. Long term simulation of {sup 137}Cs radioactivity in the regional ocean following the Fukushima Daiichi nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Tsumune, D.; Tsubono, T.; Misumi, K.; Yoshida, Y.; Hayami, H. [Central Research Institute of Electric Power Industry (Japan); Aoyama, M. [Meteorological Research Institute (Japan); Uematsu, M. [University of Tokyo (Japan); Maeda, Y. [CERES, Inc. (Japan)

    2014-07-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. A regional-scale simulation of {sup 137}Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of {sup 137}Cs deposited on the ocean by atmospheric deposition outside the domain of the model for more than two years. Direct releases of {sup 131}I, {sup 134}Cs, and {sup 137}Cs were estimated for 1 year after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released {sup 131}I, {sup 134}Cs, and {sup 137}Cs were 11.1±2.2 PBq, 3.5±0.7 PBq, and 3.6±0.7 PBq, respectively. The contributions of each source were estimated by analysis of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs activity ratios and comparisons between simulated results and measured activities of {sup 137}Cs. Simulated {sup 137}Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated {sup 137}Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured {sup 137}Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated {sup 137}Cs activities attributable to the inflow of {sup 137}Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the

  5. Generalities on nuclear accidents and their short-dated and middle-dated management; Generalites sur les accidents nucleaires et leur gestion a court terme et a long terme

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    All the nuclear activities present a radiation risk. The radiation exposure of the employees or the public, may occur during normal activity or during an accident. The IRSN realized a document on this radiation risk and the actions of protection. The sanitary and medical aspects of a radiation accident are detailed. The actions of the population protection during an accident and the post accident management are also discussed. (A.L.B.)

  6. The development of a realistic source term for sodium-cooled fast reactors : assessment of current status and future needs.

    Energy Technology Data Exchange (ETDEWEB)

    LaChance, Jeffrey L.; Phillips, Jesse; Parma, Edward J., Jr.; Olivier, Tara Jean; Middleton, Bobby D.

    2011-06-01

    Sodium-cooled fast reactors (SFRs) continue to be proposed and designed throughout the United States and the world. Although the number of SFRs actually operating has declined substantially since the 1980s, a significant interest in advancing these types of reactor systems remains. Of the many issues associated with the development and deployment of SFRs, one of high regulatory importance is the source term to be used in the siting of the reactor. A substantial amount of modeling and experimental work has been performed over the past four decades on accident analysis, sodium coolant behavior, and radionuclide release for SFRs. The objective of this report is to aid in determining the gaps and issues related to the development of a realistic, mechanistically derived source term for SFRs. This report will allow the reader to become familiar with the severe accident source term concept and gain a broad understanding of the current status of the models and experimental work. Further, this report will allow insight into future work, in terms of both model development and experimental validation, which is necessary in order to develop a realistic source term for SFRs.

  7. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-02-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  8. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-01-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  9. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-10-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  10. Fission Product Transport and Source Terms in HTRs: Experience from AVR Pebble Bed Reactor

    Directory of Open Access Journals (Sweden)

    Rainer Moormann

    2008-01-01

    Full Text Available Fission products deposited in the coolant circuit outside of the active core play a dominant role in source term estimations for advanced small pebble bed HTRs, particularly in design basis accidents (DBA. The deposited fission products may be released in depressurization accidents because present pebble bed HTR concepts abstain from a gas tight containment. Contamination of the circuit also hinders maintenance work. Experiments, performed from 1972 to 88 on the AVR, an experimental pebble bed HTR, allow for a deeper insight into fission product transport behavior. The activity deposition per coolant pass was lower than expected and was influenced by fission product chemistry and by presence of carbonaceous dust. The latter lead also to inconsistencies between Cs plate out experiments in laboratory and in AVR. The deposition behavior of Ag was in line with present models. Dust as activity carrier is of safety relevance because of its mobility and of its sorption capability for fission products. All metal surfaces in pebble bed reactors were covered by a carbonaceous dust layer. Dust in AVR was produced by abrasion in amounts of about 5 kg/y. Additional dust sources in AVR were ours oil ingress and peeling of fuel element surfaces due to an air ingress. Dust has a size of about 1  m, consists mainly of graphite, is partly remobilized by flow perturbations, and deposits with time constants of 1 to 2 hours. In future reactors, an efficient filtering via a gas tight containment is required because accidents with fast depressurizations induce dust mobilization. Enhanced core temperatures in normal operation as in AVR and broken fuel pebbles have to be considered, as inflammable dust concentrations in the gas phase.

  11. Source Term Model for an Array of Vortex Generator Vanes

    Science.gov (United States)

    Buning, P. G. (Technical Monitor); Waithe, Kenrick A.

    2003-01-01

    A source term model was developed for numerical simulations of an array of vortex generators. The source term models the side force created by a vortex generator being modeled. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on a local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low-profile vortex generator vane, which is only a fraction of the boundary layer thickness, over a flat plate. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data.

  12. [Method of ecological risk assessment for risk pollutants under short-term and high dose exposure in water pollution accident].

    Science.gov (United States)

    Lei, Bing-Li; Sun, Yan-Feng; Liu, Qian; Yu, Zhi-Qiang; Zeng, Xiang-Ying

    2011-11-01

    In recent years, water pollution accidents resulting in acute aquatic ecological risk and security issues become a research focus. However, in our country, the surface water quality standards and drinking water health standards were used to determine the safety of waters or not in pollution incidents due to lacking safety effect threshold or risk value for protection of aquatic life. In foreign countries, although predicted no effect concentration (PNEC) or risk value (R) of pollutants were provided for protection of aquatic organisms, the PNECs or risk values were derived based on long-term exposure toxicity data NOECs (no observed effect concentrations) and lack of short-term exposure risk or threshold values. For the short-term and high dose exposure in pollution incident, ecological risk assessment methods were discussed according to the procedures of the conventional ecological risk assessment and the water quality criteria establishment of the U.S. EPA for the protection of aquatic organisms in short-term exposure, and had a case study. At the same time, we provide some suggestions for the establishment of ecological risk assessment system in water pollution incidents.

  13. Simulation on In-Containment Source Term and Virtual Accident Scene of Large-Break LOCA%大破口事故安全壳内气载源项的仿真分析及事故场景虚拟

    Institute of Scientific and Technical Information of China (English)

    肖红光; 朱波; 张帆

    2011-01-01

    The variation of the concentrations of aerosol 131I, airborne 137Cs and 133Xe under 3 different disposal measures, i.e., without spray and emergency ventilation. with spray but without emergency ventilation, and with spray and emergency ventilation, was analyzed after a large-break LOCA for the small-scale experiment reactor. The results showed that the spray played an effective role in reducing the radioactive concentration of 131I and 137Cs, but almost had no effect on the inert gas 133Xe. Under the condition of this study, when the security system failed, the radioactive material would escape once the core melt. Finally, by the virtual simulation of the accident, the variation of the nuclide radioactive concentration in the whole containment was expressed intuitively in real-time and the combination of the accurate simulation data and the visual interface was achieved in this paper.%分析小型实验堆大破口事故后,冷端安全注射时在无喷淋无应急排风、有喷淋无应急排风和有喷淋有应急排风3种处置措施下,气溶胶1311I、气载137Cs和133Xe浓度的变化情况.结果表明,喷淋措施对核素131I和137Cs起到了有效降低放射性浓度的作用,但对惰性气体133Xe几乎没有影响;在本文所研究的工况下,若安全系统功能丧失,一旦堆芯裸露导致堆芯熔化,极有可能出现放射性物质外逸.最后通过对事故的虚拟仿真,将整个安全壳内核素放射性浓度变化状况实时、直观地表现出来,实现了精确仿真数据和可视化界面的有机结合.

  14. Source term assessment with ASTEC and associated uncertainty analysis using SUNSET tool

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier-Jabet, K., E-mail: karine.chevalier-jabet@irsn.fr; Cousin, F.; Cantrel, L.; Séropian, C.

    2014-06-01

    Several accidental scenarios have been simulated using the ASTEC integral IRSN-GRS code for a French 1300 MWe PWR, including several break sizes or locations, highlighting the effect of safety systems and of iodine chemistry in the reactor coolant system (RCS) and in the containment on iodine source term evaluations. Iodine chemistry in the RCS and in the containment is still subject to significant uncertainties and it is thus studied in on-going R and D programs. To assess the impact of uncertainties, ASTEC has been coupled to the IRSN uncertainty propagation and sensitivity analysis tool SUNSET. Focusing on a loss of feed-water of steam generator accident, ASTEC/SUNSET calculations have been performed to assess the effect of remaining uncertainties relative to iodine behaviour on the source term. Calculations show that the postulated lack of knowledge may impact the iodine source term in the environment by at least one decade, confirming the importance of the on-going R and D programs to improve the knowledge on iodine chemistry.

  15. A novel integrated approach for the hazardous radioactive dust source terms estimation in future nuclear fusion power plants.

    Science.gov (United States)

    Poggi, L A; Malizia, A; Ciparisse, J F; Gaudio, P

    2016-10-01

    An open issue still under investigation by several international entities working on the safety and security field for the foreseen nuclear fusion reactors is the estimation of source terms that are a hazard for the operators and public, and for the machine itself in terms of efficiency and integrity in case of severe accident scenarios. Source term estimation is a crucial key safety issue to be addressed in the future reactors safety assessments, and the estimates available at the time are not sufficiently satisfactory. The lack of neutronic data along with the insufficiently accurate methodologies used until now, calls for an integrated methodology for source term estimation that can provide predictions with an adequate accuracy. This work proposes a complete methodology to estimate dust source terms starting from a broad information gathering. The wide number of parameters that can influence dust source term production is reduced with statistical tools using a combination of screening, sensitivity analysis, and uncertainty analysis. Finally, a preliminary and simplified methodology for dust source term production prediction for future devices is presented.

  16. Source Term Analysis for the Nuclear Power Station Goesgen-Daeniken; Quelltermanalysen fuer das Kernkraftwerk Goesgen-Daeniken

    Energy Technology Data Exchange (ETDEWEB)

    Hosemann, J.P.; Megaritis, G.; Guentay, S.; Hirschmann, H.; Luebbesmeyer, D.; Lieber, K.; Jaeckel, B.; Birchley, J.; Duijvestijn, G

    2001-08-01

    Analyses are performed for three accident scenarios postulated to occur in the Goesgen Nuclear Power Plant, a 900 MWe Pressurised Water Reactor of Siemens design. The scenarios investigated comprise a Station Blackout and two separate cases of small break loss-of-coolant accident which lead, respectively, to high, intermediate and low pressure conditions in the reactor system. In each case the accident assumptions are highly pessimistic, so that the sequences span a large range of plant states and a damage phenomena. Thus the plant is evaluated for a diversity of potential safety challenges. A suite of analysis tools are used to examine the reactor coolant system response, the core heat-up, melting, fission product release from the reactor system, the transport and chemical behaviour of those fission products in the containment building, and the release of radioactivity (source term) to the environment. Comparison with reference values used by the licensing authority shows that the use of modern analysis tools and current knowledge can provide substantial reduction in the estimated source term. Of particular interest are insights gained from the analyses which indicate opportunities for operators to reduce or forestall the release. (author)

  17. Inverse modeling of the Chernobyl source term using atmospheric concentration and deposition measurements

    Directory of Open Access Journals (Sweden)

    N. Evangeliou

    2017-07-01

    Full Text Available This paper describes the results of an inverse modeling study for the determination of the source term of the radionuclides 134Cs, 137Cs and 131I released after the Chernobyl accident. The accident occurred on 26 April 1986 in the Former Soviet Union and released about 1019 Bq of radioactive materials that were transported as far away as the USA and Japan. Thereafter, several attempts to assess the magnitude of the emissions were made that were based on the knowledge of the core inventory and the levels of the spent fuel. More recently, when modeling tools were further developed, inverse modeling techniques were applied to the Chernobyl case for source term quantification. However, because radioactivity is a sensitive topic for the public and attracts a lot of attention, high-quality measurements, which are essential for inverse modeling, were not made available except for a few sparse activity concentration measurements far from the source and far from the main direction of the radioactive fallout. For the first time, we apply Bayesian inversion of the Chernobyl source term using not only activity concentrations but also deposition measurements from the most recent public data set. These observations refer to a data rescue attempt that started more than 10 years ago, with a final goal to provide available measurements to anyone interested. In regards to our inverse modeling results, emissions of 134Cs were estimated to be 80 PBq or 30–50 % higher than what was previously published. From the released amount of 134Cs, about 70 PBq were deposited all over Europe. Similar to 134Cs, emissions of 137Cs were estimated as 86 PBq, on the same order as previously reported results. Finally, 131I emissions of 1365 PBq were found, which are about 10 % less than the prior total releases. The inversion pushes the injection heights of the three radionuclides to higher altitudes (up to about 3 km than previously assumed (≈ 2.2 km in order

  18. Emergency preparedness source term development for the Office of Nuclear Material Safety and Safeguards-Licensed Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, S.L.; Mishima, J.; Ballinger, M.Y.; Lindsey, C.G.

    1984-08-01

    In order to establish requirements for emergency preparedness plans at facilities licensed by the Office of Nuclear Materials Safety and Safeguards, the Nuclear Regulatory Commission (NRC) needs to develop source terms (the amount of material made airborne) in accidents. These source terms are used to estimate the potential public doses from the events, which, in turn, will be used to judge whether emergency preparedness plans are needed for a particular type of facility. Pacific Northwest Laboratory is providing the NRC with source terms by developing several accident scenarios for eleven types of fuel cycle and by-product operations. Several scenarios are developed for each operation, leading to the identification of the maximum release considered for emergency preparedness planning (MREPP) scenario. The MREPP scenarios postulated were of three types: fire, tornado, and criticality. Fire was significant at oxide fuel fabrication, UF/sub 6/ production, radiopharmaceutical manufacturing, radiopharmacy, sealed source manufacturing, waste warehousing, and university research and development facilities. Tornadoes were MREPP events for uranium mills and plutonium contaminated facilities, and criticalities were significant at nonoxide fuel fabrication and nuclear research and development facilities. Techniques for adjusting the MREPP release to different facilities are also described.

  19. 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.

  20. 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.

  1. A Mechanistic Source Term Calculation for a Metal Fuel Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2017-06-26

    A mechanistic source term (MST) calculation attempts to realistically assess the transport and release of radionuclides from a reactor system to the environment during a specific accident sequence. The U.S. Nuclear Regulatory Commission (NRC) has repeatedly stated its expectation that advanced reactor vendors will utilize an MST during the U.S. reactor licensing process. As part of a project to examine possible impediments to sodium fast reactor (SFR) licensing in the U.S., an analysis was conducted regarding the current capabilities to perform an MST for a metal fuel SFR. The purpose of the project was to identify and prioritize any gaps in current computational tools, and the associated database, for the accurate assessment of an MST. The results of the study demonstrate that an SFR MST is possible with current tools and data, but several gaps exist that may lead to possibly unacceptable levels of uncertainty, depending on the goals of the MST analysis.

  2. Selection of models to calculate the LLW source term

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M. (Brookhaven National Lab., Upton, NY (United States))

    1991-10-01

    Performance assessment of a LLW disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). In turn, many of these physical processes are influenced by the design of the disposal facility (e.g., infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This document provides a brief overview of disposal practices and reviews existing source term models as background for selecting appropriate models for estimating the source term. The selection rationale and the mathematical details of the models are presented. Finally, guidance is presented for combining the inventory data with appropriate mechanisms describing release from the disposal facility. 44 refs., 6 figs., 1 tab.

  3. Influence of iodine chemistry on source term assessment; Influencia de la quimica del yodo en la estimacion del termino fuente

    Energy Technology Data Exchange (ETDEWEB)

    Herranz Puebla, L. E.; Lopez Diez, I.; Rodriguez Maroto, J. J.; Martinez Lopez-Alcorocho, A.

    1991-07-01

    The major goal of a phenomenology analysis of containment during a severe accident situation can be spitted into the following ones: to know the containment response to the different loads and to predict accurately the fission product and aerosol behavior. In this report, the main results coming from the study of a hypothetical accident scenario, based on LA-4 experiment of LACE project, are presented. In order to do it, several codes have been coupled: CONTEMPT4/MOD5 (thermohydraulics), NAUA/MOD5 (aerosol physics) and IODE (iodine chemistry). It has been demonstrated the impossibility of assessing with confidence the Source Term if the chemical conduct of some radionuclides is not taken into account. In particular, the influence on the iodine retention efficiency of the sump of variables such as pH has been proven. (Author)12 refs.

  4. Charge-exchange source terms in magnetohydrodynamic plasmas

    Science.gov (United States)

    DeStefano, Anthony M.; Heerikhuisen, Jacob

    2017-05-01

    In the modeling of space plasma environments, source terms are often used to couple separate species of particles and/or fluids. There have been many techniques developed over the years to make such coupling more tractable while maintaining maximum physical fidelity. In our current application we use the formalism of the Boltzmann collision integral to compute source terms due to charge-exchange events in the heliosphere. The charge-exchange cross sections often encountered in heliospheric interactions can be fit to laboratory data, but in most cases cannot be directly integrated over analytically. Therefore, researchers often employ various levels of approximation, either semi-analytic or numerical. We explore several assumptions to the charge-exchange source term integrals, namely using Maxwellian velocity spaces for like-mass species and either hard-sphere, power-law, or exact forms of the cross section.

  5. Comparison of the Chernobyl and Fukushima nuclear accidents: a review of the environmental impacts.

    Science.gov (United States)

    Steinhauser, Georg; Brandl, Alexander; Johnson, Thomas E

    2014-02-01

    The environmental impacts of the nuclear accidents of Chernobyl and Fukushima are compared. In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident. In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, cesium, tellurium). However, the amount of refractory elements (including actinides) emitted in the course of the Chernobyl accident was approximately four orders of magnitude higher than during the Fukushima accident. For Chernobyl, a total release of 5,300 PBq (excluding noble gases) has been established as the most cited source term. For Fukushima, we estimated a total source term of 520 (340-800) PBq. In the course of the Fukushima accident, the majority of the radionuclides (more than 80%) was transported offshore and deposited in the Pacific Ocean. Monitoring campaigns after both accidents reveal that the environmental impact of the Chernobyl accident was much greater than of the Fukushima accident. Both the highly contaminated areas and the evacuated areas are smaller around Fukushima and the projected health effects in Japan are significantly lower than after the Chernobyl accident. This is mainly due to the fact that food safety campaigns and evacuations worked quickly and efficiently after the Fukushima accident. In contrast to Chernobyl, no fatalities due to acute radiation effects occurred in Fukushima. © 2013.

  6. Flowsheets and source terms for radioactive waste projections

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W. (comp.)

    1985-03-01

    Flowsheets and source terms used to generate radioactive waste projections in the Integrated Data Base (IDB) Program are given. Volumes of each waste type generated per unit product throughput have been determined for the following facilities: uranium mining, UF/sub 6/ conversion, uranium enrichment, fuel fabrication, boiling-water reactors (BWRs), pressurized-water reactors (PWRs), and fuel reprocessing. Source terms for DOE/defense wastes have been developed. Expected wastes from typical decommissioning operations for each facility type have been determined. All wastes are also characterized by isotopic composition at time of generation and by general chemical composition. 70 references, 21 figures, 53 tables.

  7. Short-term associations between outdoor air pollution and visits to accident and emergency departments in London for respiratory complaints

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, R.W.; Anderson, H.R.; Strachan, D.P.; Bland, J.M.; Bremner, S.A. [St. George`s Hospital Medical School, Dept. of Public Health Sciences, London (United Kingdom); Ponce de Leon, A. [IME/UERJ Rua Sao Francisco Xavier, Dept. de Estatistica, Maracana Rio de Janeiro (Brazil)

    1999-02-01

    Many epidemiological studies have shown positive short-term associations between health and current levels of outdoor air pollution. The aim of this study was to investigate the association between air pollution and the number of visits to accident and emergency (A and E) departments in London for respiratory complaints. A and E visits include the less severe cases of acute respiratory disease and are unrestricted by bed availability. Daily counts of visits to 12 London A and E departments for asthma, other respiratory complaints, and both combined for a number of age groups were constructed from manual registers of visits for the period 1992-1994. A poison regression allowing for seasonal patterns meteorological conditions and influenza epidemics was used to assess the associations between the number of visits and six pollutants: nitrogen dioxide, ozone, sulphur dioxide, carbon monoxide, and particles measured as black smoke (BS) and particles with a median aerodynamic diameter of <10 {mu}m (PM10). After making an allowance for the multiplicity of tests, there remained strong associations between visits for all respiratory complaints and increases in SO{sub 2}: a 2.8% (95% confidence interval (CI) 0.7-4.9) increase in the number of visits for a 18 {mu}g{sup .}m{sup -3} increase (10th-90th percentile range) and a 3.0% (95% Cl 0.8-5.2) increase for a 31 {mu}g{sup .}m{sup -3} increase in PM10. There were also significant associations between visits for asthma and SO{sub 2}, NO{sub 2} and PM10. No significant associations between O{sub 3} and any of the respiratory complaints investigated were found. Because of the strong correlation between pollutants, it was difficult to identify a single pollutant responsible for the associations found in the analyses. This study suggests that the levels of air pollution currently experienced in London are linked to short-term increases in the number of people visiting accident and emergency departments with respiratory complaints

  8. Short-term associations between outdoor air pollution and visits to accident and emergency departments in London for respiratory complaints

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, R.W.; Anderson, H.R.; Strachan, D.P.; Bland, J.M.; Bremner, S.A. [St. George' s Hospital Medical School, Dept. of Public Health Sciences, London (United Kingdom); Ponce de Loen, A. [IME/UERJ Rua Sao Francisco Xavier, Dept. de Estatistica, Maracana Rio de Janeiro , RJ (Brazil)

    1999-07-01

    Many epidemiological studies have shown positive short-term associations between health and current levels of outdoor air pollution. The aim of this study was to investigate the association between air pollution and the number of visits to accident and emergency (A and E) departments in London for respiratory complaints. A and E visits include the less severe cases of acute respiratory disease and are unrestricted by bed availability. Daily counts of visits to 12 London A and E departments for asthma, other respiratory complaints, and both combined for a number of age groups were constructed from manual registers of visits for the period 1992-1994. A Poisson regression allowing for seasonal patterns, meteorological conditions and influenza epidemics was used to assess the associations between the number of visits and six pollutants: nitrogen dioxide, ozone, sulphur dioxide, carbon monoxide, and particles measured as black smoke (BS) and particles with a median aerodynamic diameter of <10 {mu}m (PM10). After making an allowance for the multiplicity of tests, there remained strong associations between visits for all respiratory complaints and increases in SO{sub 2}: a 2.8% (95% confidence interval (CI) 0.7-4.9) increase in the number of visits for a 18 {mu}g{sup .}m{sup -3} increase (10th-90th percentile range) and a 3.0% (95% CI 0.8-5.2) increase for a 31 {mu}g{sup .}m{sup -3} increase in PM10. There were also significant associations between visits for asthma and SO{sub 2}, NO{sub 2} and PM10. No significant associations between O{sub 3} and any of the respiratory complaints investigated were found. Because of the strong correlation between pollutants, it was difficult to identify a single pollutant responsible for the associations found in the analyses. This study suggests that the levels of air pollution currently experineced in London are linked to short-term increases in the number of people visiting accident and emergency departments with respiratory

  9. Multi-stage ranking of emergency technology alternatives for water source pollution accidents using a fuzzy group decision making tool.

    Science.gov (United States)

    Qu, Jianhua; Meng, Xianlin; You, Hong

    2016-06-05

    Due to the increasing number of unexpected water source pollution events, selection of the most appropriate disposal technology for a specific pollution scenario is of crucial importance to the security of urban water supplies. However, the formulation of the optimum option is considerably difficult owing to the substantial uncertainty of such accidents. In this research, a multi-stage technical screening and evaluation tool is proposed to determine the optimal technique scheme, considering the areas of pollutant elimination both in drinking water sources and water treatment plants. In stage 1, a CBR-based group decision tool was developed to screen available technologies for different scenarios. Then, the threat degree caused by the pollution was estimated in stage 2 using a threat evaluation system and was partitioned into four levels. For each threat level, a corresponding set of technique evaluation criteria weights was obtained using Group-G1. To identify the optimization alternatives corresponding to the different threat levels, an extension of TOPSIS, a multi-criteria interval-valued trapezoidal fuzzy decision making technique containing the four arrays of criteria weights, to a group decision environment was investigated in stage 3. The effectiveness of the developed tool was elaborated by two actual thallium-contaminated scenarios associated with different threat levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Alternative Source Terms for SWAN in the Coastal Region

    NARCIS (Netherlands)

    Salmon, J.E.; Holthuijsen, L.H.; Smit, P.B.; Van Vledder, G.P.; Zijlema, M.

    2014-01-01

    This paper presents the application of new source terms in SWAN for the dominant water wave physics in the coastal zone: depth-induced breaking and triad wave-wave interactions. We present results demonstrating increased modelling skill in the prediction of bulk wave parameters e.g. significant wave

  11. BWR ASSEMBLY SOURCE TERMS FOR WASTE PACKAGE DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    T.L. Lotz

    1997-02-15

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide boiling water reactor (BWR) assembly radiation source term data for use during Waste Package (WP) design. The BWR assembly radiation source terms are to be used for evaluation of radiolysis effects at the WP surface, and for personnel shielding requirements during assembly or WP handling operations. The objectives of this evaluation are to generate BWR assembly radiation source terms that bound selected groupings of BWR assemblies, with regard to assembly average burnup and cooling time, which comprise the anticipated MGDS BWR commercial spent nuclear fuel (SNF) waste stream. The source term data is to be provided in a form which can easily be utilized in subsequent shielding/radiation dose calculations. Since these calculations may also be used for Total System Performance Assessment (TSPA), with appropriate justification provided by TSPA, or radionuclide release rate analysis, the grams of each element and additional cooling times out to 25 years will also be calculated and the data included in the output files.

  12. Disposal Unit Source Term (DUST) data input guide

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M. [Brookhaven National Lab., Upton, NY (United States)

    1993-05-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). The computer code DUST (Disposal Unit Source Term) has been developed to model these processes. This document presents the models used to calculate release from a disposal facility, verification of the model, and instructions on the use of the DUST code. In addition to DUST, a preprocessor, DUSTIN, which helps the code user create input decks for DUST and a post-processor, GRAFXT, which takes selected output files and plots them on the computer terminal have been written. Use of these codes is also described.

  13. 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-term

  14. Evaluation of source term induced by beam loss in the superconducting linear accelerator at RAON

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Jin; Kim, Su Na; Nam, Shin Woo; Chung, Yon Sei [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2014-11-15

    As a new world-class heavy ion accelerator, RAON is able to accelerate heavy ions from proton to uranium with the energy up to -400 MeV/u and produce rare isotopes. These high purity, high intensity, and high energy beams generate the various secondary radiation which will impact on the shielding aspects of the main linear accelerator tunnels. In the main tunnel the secondary neutrons are produced by uniform beam-loss or accident criteria. In this paper evaluations of several source terms induced by beam-loss will be discussed along with the physics model of the Monte Carlo simulation codes. The beam-loss criteria were tested for the evaluation of source term for the main beam line tunnel of the RAON accelerator. It was found that the amount of the secondary neutrons depends on the incident angle of projectile on the beam pipe and the mass and energy of projectile. The influence of selected physics models and libraries of MCNPX and PHITS has been examined. The secondary neutrons were produced most in the CEM and LAQGSM model.

  15. Impact of inhospital stent thrombosis and cerebrovascular accidents on long-term prognosis after percutaneous coronary intervention.

    Science.gov (United States)

    Guerra, Elena; Ndrepepa, Gjin; Schulz, Stefanie; Byrne, Robert; Hoppmann, Petra; Kufner, Sebastian; Ibrahim, Tareq; Tada, Tomohisa; Schunkert, Heribert; Laugwitz, Karl-Ludwig; Kastrati, Adnan

    2014-12-01

    Inhospital stent thrombosis (ST) and cerebrovascular accidents (CVA) are rare but serious adverse events after percutaneous coronary intervention (PCI). The association of ST or CVA with long-term outcome after PCI remains poorly investigated. The study included 18,334 consecutive patients who underwent PCI. Patients were divided into 3 groups: the group with ST, the group with CVA, and the group without these events. The primary outcome was all-cause mortality at 3-year follow-up. Inhospital ST or CVA occurred in 59 patients (0.32%) and in 90 patients (0. 49%), respectively. There were 2,149 deaths (11.7%) during the follow-up: 26 deaths among patients with ST, 32 deaths among patients with CVA, and 2,091 deaths among patients without ST or CVA (Kaplan-Meier estimates of 3-year mortality 45.3%, 38.0%, and 12.9%, odds ratio 6.1, 95% CI 3.6-10.2, P CVA and odds ratio 4.2 [2.7-6.6], P CVA group vs the group without ST or CVA). There was no significant difference in the 3-year mortality between CVA and ST groups (P = .29). The Cox proportional hazards model showed that ST (adjusted hazard ratio 4.97, 95% CI 2.58-9.56, P CVA (adjusted hazard ratio 2.25 [1.25-4.04], P = .006) were independently associated with the increased risk of 3-year mortality. Inhospital ST and CVA after PCI are associated with the increased risk of 3-year mortality. Both events seem to have a similar impact on long-term survival. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Definition of loss-of-coolant accident radiation source: summary and conclusions. [BWR; PWR

    Energy Technology Data Exchange (ETDEWEB)

    Bonzon, L.L.; Lurie, N.A.; Houston, D.H.; Naber, J.A.

    1978-05-01

    The radiation energy release rates and spectra corresponding to those sources specified in USNRC Regulatory Guide 1.89 for the radiation qualification of Class 1E equipment were calculated. The effects of several parameters (some not specific in the Guide), such as reactor fuel composition, operating duration and power level, and treatment of progeny, are evaluated. The results are presented as time-dependent beta and gamma-ray energy release rates and spectra which are fundamental quantities that are not specific to a plant design but are generally applicable to any nuclear power station.

  17. Radiological Source Terms for Tank Farms Safety Analysis

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    2000-06-27

    This document provides Unit Liter Dose factors, atmospheric dispersion coefficients, breathing rates and instructions for using and customizing these factors for use in calculating radiological doses for accident analyses in the Hanford Tank Farms.

  18. Source term evaluation for accident transients in the experimental fusion facility ITER

    Energy Technology Data Exchange (ETDEWEB)

    Virot, F.; Barrachin, M.; Cousin, F. [IRSN, BP3-13115, Saint Paul lez Durance (France)

    2015-03-15

    We have studied the transport and chemical speciation of radio-toxic and toxic species for an event of water ingress in the vacuum vessel of experimental fusion facility ITER with the ASTEC code. In particular our evaluation takes into account an assessed thermodynamic data for the beryllium gaseous species. This study shows that deposited beryllium dusts of atomic Be and Be(OH){sub 2} are formed. It also shows that Be(OT){sub 2} could exist in some conditions in the drain tank. (authors)

  19. Inverse modelling-based reconstruction of the Chernobyl source term available for long-range transport

    Directory of Open Access Journals (Sweden)

    X. Davoine

    2007-01-01

    Full Text Available The reconstruction of the Chernobyl accident source term has been previously carried out using core inventories, but also back and forth confrontations between model simulations and activity concentration or deposited activity measurements. The approach presented in this paper is based on inverse modelling techniques. It relies both on the activity concentration measurements and on the adjoint of a chemistry-transport model. The location of the release is assumed to be known, and one is looking for a source term available for long-range transport that depends both on time and altitude. The method relies on the maximum entropy on the mean principle and exploits source positivity. The inversion results are mainly sensitive to two tuning parameters, a mass scale and the scale of the prior errors in the inversion. To overcome this hardship, we resort to the statistical L-curve method to estimate balanced values for these two parameters. Once this is done, many of the retrieved features of the source are robust within a reasonable range of parameter values. Our results favour the acknowledged three-step scenario, with a strong initial release (26 to 27 April, followed by a weak emission period of four days (28 April–1 May and again a release, longer but less intense than the initial one (2 May–6 May. The retrieved quantities of iodine-131, caesium-134 and caesium-137 that have been released are in good agreement with the latest reported estimations. Yet, a stronger apportionment of the total released activity is ascribed to the first period and less to the third one. Finer chronological details are obtained, such as a sequence of eruptive episodes in the first two days, likely related to the modulation of the boundary layer diurnal cycle. In addition, the first two-day release surges are found to have effectively reached an altitude up to the top of the domain (5000 m.

  20. Inverse modelling-based reconstruction of the Chernobyl source term available for long-range transport

    Directory of Open Access Journals (Sweden)

    X. Davoine

    2007-01-01

    Full Text Available The reconstruction of the Chernobyl accident source term has been previously carried out using core inventories, but also back and forth confrontations between model simulations and activity concentration or deposited activity measurements. The approach presented in this paper is based on inverse modelling techniques. It relies both on the activity concentration measurements and on the adjoint of a chemistry-transport model. The location of the release is assumed to be known, and one is looking for a source term available for long-range transport that depends both on time and altitude. The method relies on the maximum entropy on the mean principle and exploits source positivity. The inversion results are mainly sensitive to two tuning parameters, a mass scale and the scale of the prior errors in the inversion. To overcome this hardship, we resort to the statistical L-curve method to estimate balanced values for these two parameters. Once this is done, many of the retrieved features of the source are robust within a reasonable range of parameter values. Our results favour the acknowledged three-step scenario, with a strong initial release (26 to 27 April, followed by a weak emission period of four days (28 April–1 May and again a release, longer but less intense than the initial one (2 May–6 May. The retrieved quantities of iodine-131, caesium-134 and caesium-137 that have been released are in good agreement with the latest reported estimations. Yet, a stronger apportionment of the total released activity is ascribed to the first period and less to the third one. Finer chronological details are obtained, such as a sequence of eruptive episodes in the first two days, likely related to the modulation of the boundary layer diurnal cycle. In addition, the first two-day release surges are found to have effectively reached an altitude up to the top of the domain (5000 m.

  1. Lessons learned from accidents investigations

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Bello, P. [Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico City (Mexico); Croft, J. [National Radiological Protection Board (United Kingdom); Glenn, J

    1997-12-31

    Accidents from three main practices: medical applications, industrial radiography and industrial irradiators are used to illustrate some common causes of accidents and the main lessons to be learned. A brief description of some of these accidents is given. Lessons learned from the described accidents are approached by subjects covering: safety culture, quality assurance, human factors, good engineering practice, defence in depth, security of sources, safety assessment and monitoring and verification compliance. (author)

  2. Brines as Sources of Long-term Subsurface Contamination

    Science.gov (United States)

    Flowers, T. C.; Hunt, J. R.

    2004-12-01

    Concentrated salt solutions, i.e. brines, are source terms for environmental contaminants released into surface waters and groundwaters. Brines arise from both natural and industrial processes such as natural salt deposits, solid rocket fuel production, landfill leachates, nuclear fuel reprocessing, and acid rock drainage. Additionally, many of the in-situ remediation fluids that have been implemented at the pilot or the field scale are also classified as brines. While brines are miscible with water, mixing processes are slow in the subsurface and this constrains the dilution of contaminants present within brines and the delivery of remediation fluids to sites where reactions are needed. The mixing of brines during their vertical migration through aquifers is determined by aquifer permeability as well as differences in density and viscosity between the brine and the ambient groundwater. The stability criterion for brine displacement was predicted in 1952 by Hill and the resulting dispersion at the mixing front is quantified by a compilation of literature data and the acquisition of new experimental data. As brines sink through aquifers, they become emplaced in less accessible locations where mass transfer models predict that contaminants within brines are slowly released into flowing groundwater. For radioactive wastes and environmental contaminants with very low acceptable concentrations, groundwater quality can be impacted for decades. Field data from a cooling water disposal site suggest that a dense brine is likely still present as a source term 40 years after waste disposal was stopped. Overall, analysis of pollution sources, quantification of transport processes, generalization of laboratory data, and limited evaluation of field data indicate that brines represent long-term sources of groundwater contamination and that source control has not been seriously addressed.

  3. Regulatory Technology Development Plan Sodium Fast Reactor. Mechanistic Source Term Development

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David S. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, Acacia Joann [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew D. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sofu, Tanju [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-02-28

    Construction and operation of a nuclear power installation in the U.S. requires licensing by the U.S. Nuclear Regulatory Commission (NRC). A vital part of this licensing process and integrated safety assessment entails the analysis of a source term (or source terms) that represents the release of radionuclides during normal operation and accident sequences. Historically, nuclear plant source term analyses have utilized deterministic, bounding assessments of the radionuclides released to the environment. Significant advancements in technical capabilities and the knowledge state have enabled the development of more realistic analyses such that a mechanistic source term (MST) assessment is now expected to be a requirement of advanced reactor licensing. This report focuses on the state of development of an MST for a sodium fast reactor (SFR), with the intent of aiding in the process of MST definition by qualitatively identifying and characterizing the major sources and transport processes of radionuclides. Due to common design characteristics among current U.S. SFR vendor designs, a metal-fuel, pool-type SFR has been selected as the reference design for this work, with all phenomenological discussions geared toward this specific reactor configuration. This works also aims to identify the key gaps and uncertainties in the current knowledge state that must be addressed for SFR MST development. It is anticipated that this knowledge state assessment can enable the coordination of technology and analysis tool development discussions such that any knowledge gaps may be addressed. Sources of radionuclides considered in this report include releases originating both in-vessel and ex-vessel, including in-core fuel, primary sodium and cover gas cleanup systems, and spent fuel movement and handling. Transport phenomena affecting various release groups are identified and qualitatively discussed, including fuel pin and primary coolant retention, and behavior in the cover gas and

  4. Paradigms and commonalities in atmospheric source term estimation methods

    Science.gov (United States)

    Bieringer, Paul E.; Young, George S.; Rodriguez, Luna M.; Annunzio, Andrew J.; Vandenberghe, Francois; Haupt, Sue Ellen

    2017-05-01

    Modeling the downwind hazard area resulting from the unknown release of an atmospheric contaminant requires estimation of the source characteristics of a localized source from concentration or dosage observations and use of this information to model the subsequent transport and dispersion of the contaminant. This source term estimation problem is mathematically challenging because airborne material concentration observations and wind data are typically sparse and the turbulent wind field chaotic. Methods for addressing this problem fall into three general categories: forward modeling, inverse modeling, and nonlinear optimization. Because numerous methods have been developed on various foundations, they often have a disparate nomenclature. This situation poses challenges to those facing a new source term estimation problem, particularly when selecting the best method for the problem at hand. There is, however, much commonality between many of these methods, especially within each category. Here we seek to address the difficulties encountered when selecting an STE method by providing a synthesis of the various methods that highlights commonalities, potential opportunities for component exchange, and lessons learned that can be applied across methods.

  5. Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue

    CERN Document Server

    Chen, X; Lopez-Caniego, M; Dickinson, C; Pearson, T J; Fuhrmann, L; Krichbaum, T P; Partridge, B

    2013-01-01

    Combining measurements taken using the Wilkinson Microwave Anisotropy Probe (WMAP) from 2001 to 2008 with measurements taken using Planck from 2009 to 2010, we investigate the long-term flux density variability of extragalactic radio sources selected from the Planck Early Release Compact Source Catalogue. The single-year, single-frequency WMAP maps are used to estimate yearly-averaged flux densities of the sources in the four WMAP bands: Ka (33 GHz), Q (41 GHz), V (61 GHz), and W (94 GHz). We identify 82, 67, 32, and 15 sources respectively as variable at greater than 99% confidence level in these four bands. The amplitudes of variation are comparable between bands, and are not correlated with either the flux densities or the spectral indices of the sources. The number counts of WMAP Ka-band sources are stable from year to year despite the fluctuation caused by individual source variability. Most of our sources show strong correlation in variability between bands. Almost all the sources that show variability ...

  6. Toward a Mechanistic Source Term in Advanced Reactors: Characterization of Radionuclide Transport and Retention in a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Brunett, Acacia J.; Bucknor, Matthew; Grabaskas, David

    2016-04-17

    A vital component of the U.S. reactor licensing process is an integrated safety analysis in which a source term representing the release of radionuclides during normal operation and accident sequences is analyzed. Historically, source term analyses have utilized bounding, deterministic assumptions regarding radionuclide release. However, advancements in technical capabilities and the knowledge state have enabled the development of more realistic and best-estimate retention and release models such that a mechanistic source term assessment can be expected to be a required component of future licensing of advanced reactors. Recently, as part of a Regulatory Technology Development Plan effort for sodium cooled fast reactors (SFRs), Argonne National Laboratory has investigated the current state of knowledge of potential source terms in an SFR via an extensive review of previous domestic experiments, accidents, and operation. As part of this work, the significant sources and transport processes of radionuclides in an SFR have been identified and characterized. This effort examines all stages of release and source term evolution, beginning with release from the fuel pin and ending with retention in containment. Radionuclide sources considered in this effort include releases originating both in-vessel (e.g. in-core fuel, primary sodium, cover gas cleanup system, etc.) and ex-vessel (e.g. spent fuel storage, handling, and movement). Releases resulting from a primary sodium fire are also considered as a potential source. For each release group, dominant transport phenomena are identified and qualitatively discussed. The key product of this effort was the development of concise, inclusive diagrams that illustrate the release and retention mechanisms at a high level, where unique schematics have been developed for in-vessel, ex-vessel and sodium fire releases. This review effort has also found that despite the substantial range of phenomena affecting radionuclide release, the

  7. Accident progression event tree analysis for postulated severe accidents at N Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wyss, G.D.; Camp, A.L.; Miller, L.A.; Dingman, S.E.; Kunsman, D.M. (Sandia National Labs., Albuquerque, NM (USA)); Medford, G.T. (Science Applications International Corp., Albuquerque, NM (USA))

    1990-06-01

    A Level II/III probabilistic risk assessment (PRA) has been performed for N Reactor, a Department of Energy (DOE) production reactor located on the Hanford reservation in Washington. The accident progression analysis documented in this report determines how core damage accidents identified in the Level I PRA progress from fuel damage to confinement response and potential releases the environment. The objectives of the study are to generate accident progression data for the Level II/III PRA source term model and to identify changes that could improve plant response under accident conditions. The scope of the analysis is comprehensive, excluding only sabotage and operator errors of commission. State-of-the-art methodology is employed based largely on the methods developed by Sandia for the US Nuclear Regulatory Commission in support of the NUREG-1150 study. The accident progression model allows complex interactions and dependencies between systems to be explicitly considered. Latin Hypecube sampling was used to assess the phenomenological and systemic uncertainties associated with the primary and confinement system responses to the core damage accident. The results of the analysis show that the N Reactor confinement concept provides significant radiological protection for most of the accident progression pathways studied.

  8. Long-term follow-up after accidental gamma irradiation from a {sup 192}Ir source in Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Mollah, A.S.; Begum, A.; Begum, R. [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    2006-07-01

    A industrial radiographer was accidentally over -exposed to high dose of ionizing radiation from an {sup 192}Ir source pellet during radiograph y of weld-joints in gas pipe-lines on June 10, 1985 in Bangladesh. The source, housed in a portable exposure assembly, had an activity of about 1850 GBq. A guide -tube was used to control the transfer of the source from safe storage position to the exposure position and vice versa. For radiography, the ti p of the guide tube was to be fixed to the weld -joint while the source was cranked to the exposure position. Following the elapse of the preset exposure time the source had to be cranked back to the safe stor age position. This procedure was to be repeated for each radiographic exposure. Symptoms of high radiation exposure occurred immediately after the accident and skin erythema developed leading to progressive tissue deteriorations. Biological effects such as mild vomiting, malaise, nausea and diarrhea occurred within a short period after the accident. Skin erythema, swelling and tenderness of the palmar surfaces and the tips of the thumbs, index fingers and middle fingers of the both hands accompanied by severe pain and inflammation developed within 7 days of the mishap. The inflammatory changes characterized by redness and bullae spread over the affected fingers with severe pain and agony within a few days. The finger -tips developed abscesses with enormous pus formation and the affected finger nails fell off. He also developed toothache. At this stage a medical practitioner made some surgical dressings and prescribed antibiotics. During the first six months the most serious health disorder was local necroses of the skin and the deep layers of the palmar side of the affected fingers with sharply delineated injuries. The clinical findings were consistent with those reported elsewhere under similar accident conditions. The consequences of this over-exposure are being followed up to assess the long-term effects of

  9. Informational uncertainties of risk assessment about accidents of chemicals

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An analysis system of informational uncertainties for accidental risk assessment of chemicals is introduced. Statistical test methods and fuzzy sets method can do the quantitative analysis of the input parameters. The uncertainties of the model can be used by quantitative compared method for the leakage accidents of chemicals. The estimation of the leaking time is important for discussing accidental source term. The uncertain analyses of the release accident for pipeline gas (CO) liquid chlorine and liquid propane gas (LPG) have been discussed.

  10. Methodology for a bounding estimate of activation source-term.

    Science.gov (United States)

    Culp, Todd

    2013-02-01

    Sandia National Laboratories' Z-Machine is the world's most powerful electrical device, and experiments have been conducted that make it the world's most powerful radiation source. Because Z-Machine is used for research, an assortment of materials can be placed into the machine; these materials can be subjected to a range of nuclear reactions, producing an assortment of activation products. A methodology was developed to provide a systematic approach to evaluate different materials to be introduced into the machine as wire arrays. This methodology is based on experiment specific characteristics, physical characteristics of specific radionuclides, and experience with Z-Machine. This provides a starting point for bounding calculations of radionuclide source-term that can be used for work planning, development of work controls, and evaluating materials for introduction into the machine.

  11. Trace metal source terms in carbon sequestration environments.

    Science.gov (United States)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2013-01-02

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising; however, possible CO(2) or CO(2)-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define a range of concentrations that can be used as the trace element source term for reservoirs and leakage pathways in risk simulations. Storage source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from cements and sandstones, shales, carbonates, evaporites, and basalts from the Frio, In Salah, Illinois Basin, Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands, and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution was tracked by measuring solution concentrations over time under conditions (e.g., pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for maximum contaminant levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments because of the presence of CO(2). Results indicate that Cr and Pb released from sandstone reservoir and shale cap rocks exceed the MCLs by an order of magnitude, while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the trace element source term for reservoirs and leakage pathways in risk simulations to further evaluate the impact of leakage on groundwater quality.

  12. Trace Metal Source Terms in Carbon Sequestration Environments

    Energy Technology Data Exchange (ETDEWEB)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2012-02-05

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising, however, possible CO₂ or CO₂-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define trace metal source terms from the reaction of supercritical CO₂, storage reservoir brines, reservoir and cap rocks. Storage reservoir source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from sandstones, shales, carbonates, evaporites, basalts and cements from the Frio, In Salah, Illinois Basin – Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution is tracked by measuring solution concentrations over time under conditions (e.g. pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for Maximum Contaminant Levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments due to the presence of CO₂. Results indicate that Cr and Pb released from sandstone reservoir and shale cap rock exceed the MCLs by an order of magnitude while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the reservoir and caprock source term to further evaluate the impact of leakage on groundwater quality.

  13. Dose estimates from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-11-01

    The Lawrence Livermore National Laboratory Atmospheric Release Advisory Capability (ARAC) responded to the Chernobyl nuclear reactor accident in the Soviet Union by utilizing long-range atmospheric dispersion modeling to estimate the amount of radioactivity released (source term) and the radiation dose distribution due to exposure to the radioactive cloud over Europe and the Northern Hemisphere. In later assessments, after the release of data on the accident by the Soviet Union, the ARAC team used their mesoscale to regional scale model to focus in on the radiation dose distribution within the Soviet Union and the vicinity of the Chernobyl plant. 22 refs., 5 figs., 5 tabs.

  14. Fourth order wave equations with nonlinear strain and source terms

    Science.gov (United States)

    Liu, Yacheng; Xu, Runzhang

    2007-07-01

    In this paper we study the initial boundary value problem for fourth order wave equations with nonlinear strain and source terms. First we introduce a family of potential wells and prove the invariance of some sets and vacuum isolating of solutions. Then we obtain a threshold result of global existence and nonexistence. Finally we discuss the global existence of solutions for the problem with critical initial condition I(u0)[greater-or-equal, slanted]0, E(0)=d. So the Esquivel-Avila's results are generalized and improved.

  15. Quasilinear equations with source terms on Carnot groups

    CERN Document Server

    Phuc, Nguyen Cong

    2012-01-01

    In this paper we give necessary and sufficient conditions for the existence of solutions to quasilinear equations of Lane--Emden type with measure data on a Carnot group $\\mathbb G$ of arbitrary step. The quasilinear part involves operators of the $p$-Laplacian type $\\Delta_{\\mathbb G,\\,p}\\,$, $1terms of nonlinear potentials of Th. Wolff's type. As a consequence, we characterize completely removable singularities, and prove a Liouville type theorem for supersolutions of quasilinear equations with source terms which has been known only for equations involving the sub-Laplacian ($p=2$) on the Heisenberg group.

  16. 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.

  17. Comparison of the Chernobyl and Fukushima nuclear accidents: A review of the environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Steinhauser, Georg, E-mail: georg.steinhauser@colostate.edu; Brandl, Alexander; Johnson, Thomas E.

    2014-02-01

    The environmental impacts of the nuclear accidents of Chernobyl and Fukushima are compared. In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident. In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, cesium, tellurium). However, the amount of refractory elements (including actinides) emitted in the course of the Chernobyl accident was approximately four orders of magnitude higher than during the Fukushima accident. For Chernobyl, a total release of 5300 PBq (excluding noble gases) has been established as the most cited source term. For Fukushima, we estimated a total source term of 520 (340–800) PBq. In the course of the Fukushima accident, the majority of the radionuclides (more than 80%) was transported offshore and deposited in the Pacific Ocean. Monitoring campaigns after both accidents reveal that the environmental impact of the Chernobyl accident was much greater than of the Fukushima accident. Both the highly contaminated areas and the evacuated areas are smaller around Fukushima and the projected health effects in Japan are significantly lower than after the Chernobyl accident. This is mainly due to the fact that food safety campaigns and evacuations worked quickly and efficiently after the Fukushima accident. In contrast to Chernobyl, no fatalities due to acute radiation effects occurred in Fukushima. - Highlights: • The environmental effects of Chernobyl and Fukushima are compared. • Releases of radionuclides from Chernobyl exceeded Fukushima by an order of magnitude. • Chernobyl caused more severe radiation-related health effects. • Overall, Chernobyl was a much more severe nuclear accident than Fukushima. • Psychological effects are neglected but important consequences of nuclear accidents.

  18. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    Energy Technology Data Exchange (ETDEWEB)

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO/sub 2/) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO/sub 2/ pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs.

  19. The effect of gamma-ray transport on afterheat calculations for accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S.; Latkowski, J.F.; Sanz, J.

    2000-05-01

    Radioactive afterheat is an important source term for the release of radionuclides in fusion systems under accident conditions. Heat transfer calculations are used to determine time-temperature histories in regions of interest, but the true source term needs to be the effective afterheat, which considers the transport of penetrating gamma rays. Without consideration of photon transport, accident temperatures may be overestimated in others. The importance of this effect is demonstrated for a simple, one-dimensional problem. The significance of this effect depends strongly on the accident scenario being analyzed.

  20. Estimating Source Terms for Diverse Spent Nuclear Fuel Types

    Energy Technology Data Exchange (ETDEWEB)

    Brett Carlsen; Layne Pincock

    2004-11-01

    The U.S. Department of Energy (DOE) National Spent Nuclear Fuel Program is responsible for developing a defensible methodology for determining the radionuclide inventory for the DOE spent nuclear fuel (SNF) to be dispositioned at the proposed Monitored Geologic Repository at the Yucca Mountain Site. SNF owned by DOE includes diverse fuels from various experimental, research, and production reactors. These fuels currently reside at several DOE sites, universities, and foreign research reactor sites. Safe storage, transportation, and ultimate disposal of these fuels will require radiological source terms as inputs to safety analyses that support design and licensing of the necessary equipment and facilities. This paper summarizes the methodology developed for estimating radionuclide inventories associated with DOE-owned SNF. The results will support development of design and administrative controls to manage radiological risks and may later be used to demonstrate conformance with repository acceptance criteria.

  1. Tank waste source term inventory validation. Volume 1. Letter report

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.; Gaddis, L.A.; Johnson, E.D.

    1995-04-28

    The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories. This document is Volume I of the Letter Report entitled Tank Waste Source Term Inventory Validation.

  2. 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.

  3. 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.

  4. 5.0. Depletion, activation, and spent fuel source terms

    Energy Technology Data Exchange (ETDEWEB)

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

  5. Severe accident research and management in Nordic Countries - A status report

    Energy Technology Data Exchange (ETDEWEB)

    Frid, W. [Swedish Nuclear Power Inspectorate, SKI (Sweden)] (ed.)

    2002-01-01

    have been mainly concentrated on further development of accident management strategies and aids for source term predictions whereas in Finland in addition to further development of accident management strategies some important plant modifications have been carried out. (au)

  6. 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.

  7. [Long-term evacuation after the nuclear accident in Fukushima ~Different daily living under low-dose radioactive suffering~].

    Science.gov (United States)

    Ishikawa, Kazunobu

    2013-01-01

    One year has passed since the Great East Japan Earthquake and the Fukushima No. 1 nuclear power plant accident. Even currently, more than 150,000 evacuees in Fukushima Prefecture are forced to leave their home and to move throughout Japan. Because of the limited space of temporary housing and the weakening of personal ties in local communities, many families need to move and have separate lives. As a consequence, Fukushima has a serious shortage of caregivers for the elderly. There have been more than 1,300 disaster-related deaths due to shock and stress after long-distance drifts from town to town. Most of the victims were the elderly, who collapsed, caught pneumonia, suffered stroke and heart attack. Concerns about the safety of low-dose radiation exposure deprived the elderly of important contact with playing outside with their grandchildren in Fukushima. Fear of invisible radioactive contamination inactivated outdoor activities such as farming, dairy, fishing, gardening, hiking and wild-vegetable/mushroom hunting, although most of these activities have been traditionally supported by the wisdom of the elderly. Several recent questionnaire investigations revealed that older evacuees wish to go home even if the environment has significant contamination. In contrast, more than half of younger generation with small children have a different attitude. Nuclear accident brought serious social pains although it did not acutely hurt our bodies.

  8. Source term for atmospheric dispersion in pipeline rupture; Termo fonte para dispersao atmosferica em ruptura de gasoduto

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Rubem da Cunha [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Faculdade de Engenharia. Dept. de Engenharia Quimica]. E-mail: rreis@eq.pucrs.br; Leal, Cesar Antonio [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-graduacao em Engenharia Mecanica]. E-mail: leal@vortex.ufrgs.br

    2003-07-01

    The evaluation of consequences of industrial accidents requires the determination of physical effects in the several stages that compose a sequence of events that needs to be modeled. When a dangerous product is liberated accidentally, in order to the estimate of the possible number of victims in the scenario under consideration, one needs to evaluate the amount of released material, its physical state, and the amount that becomes airborne to form the source term for dispersion. Natural gas, transported in pipelines, is already crossing the state of Rio Grande do Sul, where, as well as in another areas of the country, it will be widely used. The need to overcome large distances between distribution and consuming units of natural gas implies in the use of high pressure conditions for transportation. The modeling of the behavior of the system in case of an accidents under this condition of quite severe pressure was done in a similar fashion used in a previous work where good results were obtained. The pipeline initial conditions are supercritical. In this paper, it is presented a discussion and results of the amount of natural gas that would be liberated in the form gas for further dispersion in the atmosphere, for the case of a pipeline initially in the pressure of 7 MPa and ambient temperature. (author)

  9. Approximate solution for SPP with discontinuous source term

    Directory of Open Access Journals (Sweden)

    Adžić Nevenka

    2004-01-01

    Full Text Available In this paper we shall consider self-adjoint singularly perturbed problem described by the ordinary differential equation of second order with small parameter multiplying the highest derivative and discontinuous source term, and the appropriate boundary conditions, which describes steady state of certain flow problems. The solution displays both boundary layers and an interior layer. The domain decomposition will be performed determining layer subintervals which are adapted to polynomial approximation. The division points for the interior layer are determined by the procedure similar to the one for boundary layers using appropriate resemblance function. The solution out of boundary layer is approximated by the solution of the reduced problem, and the layer solutions is approximated by truncated orthogonal series giving a smooth approximate solution upon the entire interval. The coefficients of the truncated series are evaluated using pseudospectral technique. The rate of convergence is examined and the order-of-magnitude of the error is given, using the principle of inverse monotonicity and the behavior of the pseudospectral approximations. Numerical example is included and it shows the high accuracy of the presented method. .

  10. A parameter model for dredge plume sediment source terms

    Science.gov (United States)

    Decrop, Boudewijn; De Mulder, Tom; Toorman, Erik; Sas, Marc

    2017-01-01

    The presented model allows for fast simulations of the near-field behaviour of overflow dredging plumes. Overflow dredging plumes occur when dredging vessels employ a dropshaft release system to discharge the excess sea water, which is pumped into the trailing suction hopper dredger (TSHD) along with the dredged sediments. The fine sediment fraction in the loaded water-sediment mixture does not fully settle before it reaches the overflow shaft. By consequence, the released water contains a fine sediment fraction of time-varying concentration. The sediment grain size is in the range of clays, silt and fine sand; the sediment concentration varies roughly between 10 and 200 g/l in most cases, peaking at even higher value with short duration. In order to assess the environmental impact of the increased turbidity caused by this release, plume dispersion predictions are often carried out. These predictions are usually executed with a large-scale model covering a complete coastal zone, bay, or estuary. A source term of fine sediments is implemented in the hydrodynamic model to simulate the fine sediment dispersion. The large-scale model mesh resolution and governing equations, however, do not allow to simulate the near-field plume behaviour in the vicinity of the ship hull and propellers. Moreover, in the near-field, these plumes are under influence of buoyancy forces and air bubbles. The initial distribution of sediments is therefore unknown and has to be based on crude assumptions at present. The initial (vertical) distribution of the sediment source is indeed of great influence on the final far-field plume dispersion results. In order to study this near-field behaviour, a highly-detailed computationally fluid dynamics (CFD) model was developed. This model contains a realistic geometry of a dredging vessel, buoyancy effects, air bubbles and propeller action, and was validated earlier by comparing with field measurements. A CFD model requires significant simulation times

  11. 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...

  12. 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.

  13. The Contribution of Sources to the Sustained Elevated Inventory of (137)Cs in Offshore Waters East of Japan after the Fukushima Dai-ichi Nuclear Power Station Accident.

    Science.gov (United States)

    Takata, Hyoe; Kusakabe, Masashi; Inatomi, Naohiko; Ikenoue, Takahito; Hasegawa, Kazuyuki

    2016-07-05

    We have evaluated the contribution of sources of (137)Cs to the inventory of radiocesium in waters (surface area: 6160 km(2), water volume: 753 km(3)) off Fukushima Prefecture and neighboring prefectures from May 2011 to February 2015. A time-series of the inventory of (137)Cs in the offshore waters revealed a clearly decreasing trend from May 2011 (283.4 TBq) to February 2015 (1.89 TBq). The (137)Cs inventory about four years after the accident was approximately twice the background inventory of 1.1 TBq. The magnitudes of the (137)Cs influxes from sources into offshore waters for periods of 182-183 days were estimated from the first period (1 October 2011 to 31 March 2012: 15.3 TBq) to the last period (1 October 2014 to 31 March 2015: 0.41 TBq). We assumed that three sources contributed (137)Cs: continuous direct discharge from the Fukushima Dai-ichi Nuclear Power Station (FNPS) even after the massive discharge in late March 2011, desorption/dissolution from sediments, and fluvial input. Quantification of these sources indicated that the direct discharge from the FNPS is the principal source of (137)Cs to maintain the relatively high inventory in the offshore area.

  14. Termination of light-water reactor core-melt accidents with a chemical core catcher: the core-melt source reduction system (COMSORS)

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Parker, G.W.; Rudolph, J.C.; Osborne-Lee, I.W. [Oak Ridge National Lab., TN (United States); Kenton, M.A. [Dames and Moore, Westmont, IL (United States)

    1996-09-01

    The Core-Melt Source Reduction System (COMSORS) is a new approach to terminate light-water reactor core melt accidents and ensure containment integrity. A special dissolution glass is placed under the reactor vessel. If core debris is released onto the glass, the glass melts and the debris dissolves into the molten glass, thus creating a homogeneous molten glass. The molten glass, with dissolved core debris, spreads into a wide pool, distributing the heat for removal by radiation to the reactor cavity above or by transfer to water on top of the molten glass. Expected equilibrium glass temperatures are approximately 600 degrees C. The creation of a low-temperature, homogeneous molten glass with known geometry permits cooling of the glass without threatening containment integrity. This report describes the technology, initial experiments to measure key glass properties, and modeling of COMSORS operations.

  15. Quantum correlations in nuclear mean field theory through source terms

    CERN Document Server

    Lee, S J

    1996-01-01

    Starting from full quantum field theory, various mean field approaches are derived systematically. With a full consideration of external source dependence, the stationary phase approximation of an action gives a nuclear mean field theory which includes quantum correlation effects (such as particle-hole or ladder diagram) in a simpler way than the Brueckner-Hartree-Fock approach. Implementing further approximation, the result can be reduced to Hartree-Fock or Hartree approximation. The role of the source dependence in a mean field theory is examined.

  16. Radiological accidents balance in medicine; Bilan des accidents radiologiques en medecine

    Energy Technology Data Exchange (ETDEWEB)

    Nenot, J.C.

    1995-12-31

    This work deals with the radiological accidents in medicine. In medicine, the radiation accidents on medical personnel and patients can be the result of over dosage and bad focusing of radiotherapy sealed sources. Sometimes, the accidents, if they are unknown during a time enough for the source to be spread and to expose a lot of persons (in the case of source dismantling for instance) can take considerable dimensions. Others accidents can come from bad handling of linear accelerators and from radionuclide kinetics in some therapies. Some examples of accidents are given. (O.L.). 11 refs.

  17. The Fukushima nuclear accident and the pale grass blue butterfly: evaluating biological effects of long-term low-dose exposures.

    Science.gov (United States)

    Hiyama, Atsuki; Nohara, Chiyo; Taira, Wataru; Kinjo, Seira; Iwata, Masaki; Otaki, Joji M

    2013-08-12

    On August 9th 2012, we published an original research article in Scientific Reports, concluding that artificial radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant exerted genetically and physiologically adverse effects on the pale grass blue butterfly Zizeeria maha in the Fukushima area. Immediately following publication, many questions and comments were generated from all over the world. Here, we have clarified points made in the original paper and answered questions posed by the readers. The following points were clarified. (1) There are many advantages to using the pale grass blue butterfly as an indicator species. (2) The forewings of the individuals collected in Fukushima were significantly smaller than in the northern and southern localities. (3) We observed growth retardation in the butterflies from the Fukushima area. (4) The aberrant colour patterns in the butterflies obtained in the Fukushima area were different from the colour patterns induced by temperature and sibling crosses but similar to those induced by external and internal exposures to the artificial radionuclides and by a chemical mutagen, suggesting that genetic mutations caused the aberrations. (5) This species of butterfly has been plentiful in Fukushima area for at least half a century. We here present specimens collected from Fukushima Prefecture before the accident. (6) Mutation accumulation was detected by the increase in the abnormality rates from May 2011 to September 2011. (7) The abnormal traits were heritable. (8) Our sampling localities were not affected by the tsunami. (9) We used a high enough number of samples to obtain statistically significant results. (10) The standard rearing method was followed, producing normal adults in the control groups. (11) The exposure experiments successfully reproduced the results of the field work. This species of butterfly is vulnerable to long-term low-dose internal and external exposures; however, insect cells are known to be

  18. CHALLENGES IN SOURCE TERM MODELING OF DECONTAMINATION AND DECOMMISSIONING WASTES.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.

    2006-08-01

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., ''urban canyons''. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City's (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used

  19. Long-term assessment of airborne radio-cesium after the Fukushima nuclear accident: re-suspension from soil and vegetation

    Science.gov (United States)

    Kajino, Mizuo; Ishizuka, Masahide; Igarashi, Yasuhito; Kita, Kazuyuki; Yoshikawa, Chisato; Inatsu, Masaru

    2016-04-01

    Long-term assessment of Cs-137 re-suspension from contaminated soil and vegetation due to the Fukushima nuclear accident in March 2011 and the on-going emission from the premises of the power plant has been conducted using a numerical simulation, a field experiment on the dust deflation at Namie in the restricted habitation area, and air concentration measurements in and out of the area, Namie and Tsukuba, respectively. The analysis period is one year from December 2012, about one and a half years from the accident, up to December 2013. The surface concentration of Cs-137 at Namie was high in the summer (~1 mBq/m3) and low in the winter (0.1-1 mBq/m3). The Cs-137 concentration was about one order smaller in Tsukuba (0.01-0.1 mBq/m3). The differences in the two sites are consistent between the observation and the simulation. Ishizuka et al. (2016) developed a numerical module of Cs-137 re-suspension associated with dust deflation based on the flux measurement in Namie. Using the module, the simulated Cs-137 from soil had a potential to account for the observed surface concentration in Namie in the winter, but underestimated by 1-2 orders of magnitude in the summer. The Tokyo Electric Power Company assessed the Cs-137 emission from the reactor buildings in 2013 as approximately 1e6 Bq/h. By using the emission rate, the simulation substantially underestimated the observation by 2-3 orders of magnitude in Namie. We simulated the re-suspension from vegetation applying a seasonal variation as a function of the green fraction map, obtained from the database of Chen and Dudhia (2001). With the constant re-suspension rate of 1e-7 [/h], the simulated vegetation re-suspension quantitatively accounted for the observed surface concentration together with its seasonal variation. Still, so far, the re-suspension mechanism has not been fully understood and thus further investigations for the understanding of the mechanisms and its long-term effects on the environment are needed.

  20. Numerical simulation of radioisotope's dependency on containment performance for large dry PWR containment under severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Mehboob, Khurram, E-mail: khurramhrbeu@gmail.com [College of Nuclear Science and Technology, Harbin Engineering University, 145-31 Nantong Street, Nangang District, Harbin, Heilongjiang 150001 (China); Xinrong, Cao [College of Nuclear Science and Technology, Harbin Engineering University, 145-31 Nantong Street, Nangang District, Harbin, Heilongjiang 150001 (China); Ahmed, Raheel [College of Automation, Harbin Engineering University, 145-31 Nantong Street, Nangang District, Harbin, Heilongjiang 150001 (China); Ali, Majid [College of Nuclear Science and Technology, Harbin Engineering University, 145-31 Nantong Street, Nangang District, Harbin, Heilongjiang 150001 (China)

    2013-09-15

    Highlights: • Calculation and comparison of activity of BURN-UP code with ORIGEN2 code. • Development of SASTC computer code. • Radioisotopes dependency on containment ESFs. • Mitigation in atmospheric release with ESFs operation. • Variation in radioisotopes source term with spray flow and pH value. -- Abstract: During the core melt accidents large amount of fission products can be released into the containment building. These fission products escape into the environment to contribute in accident source term. The mitigation in environmental release is demanded for such radiological consequences. Thus, countermeasures to source term, mitigations of release of radioactivity have been studied for 1000 MWe PWR reactor. The procedure of study is divided into five steps: (1) calculation and verification of core inventory, evaluated by BURN-UP code, (2) containment modeling based on radioactivity removal factors, (3) selection of potential accidents initiates the severe accident, (4) calculation of release of radioactivity, (5) study the dependency of release of radioactivity on containment engineering safety features (ESFs) inducing mitigation. Loss of coolant accident (LOCA), small break LOCA and flow blockage accidents (FBA) are selected as initiating accidents. The mitigation effect of ESFs on source term has been studied against ESFs performance. Parametric study of release of radioactivity has been carried out by modeling and simulating the containment parameters in MATLAB, which takes BURN-UP outcomes as input along with the probabilistic data. The dependency of iodine and aerosol source term on boric and caustic acid spray has been determined. The variation in source term mitigation with the variation of containment spray flow rate and pH values have been studied. The variation in containment retention factor (CRF) has also been studied with the ESF performance. A rapid decrease in source term is observed with the increase in pH value.

  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. Source term reduction at DAEC (including stellite ball recycling)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.; Schebler, D. [Duane Arnold Energy Center, Palo, IA (United States)

    1995-05-01

    The Duane Arnold Energy Center was seeking methods to reduce dose rates from the drywell due to Co-60. Duane Arnold is known in the industry to have one of the highest drywell dose rates from the industry standardized `BRAC` point survey. A prime method to reduce dose rates due to Co-60 is the accelerated replacement of stellite pins and rollers in control rod blades due to their high stellite (cobalt) content. Usually the cobalt content in alloys of stellite is greater than 60% cobalt by weight. During the RFO-12 refueling outage at Duane Arnold, all of the remaining cobalt bearing control rod blades were replaced and new stellite free control rod blades were installed in the core. This left Duane Arnold with the disposal of highly radioactive stellite pins and rollers. The processing of control rod blades for disposal is a very difficult evolution. First, the velocity limiter (a bottom portion of the component) and the highly radioactive upper stellite control rod blade ins and rollers are separated from the control rod blade. Next, the remainder of the control rod blade is processed (chopped and/or crushed) to aid packaging the waste for disposal. The stellite bearings are then often carefully placed in with the rest of the waste in a burial liner to provide shielding for disposal or more often are left as `orphans` in the spent fuel pool because their high specific activity create shipping and packaging problems. Further investigation by the utility showed that the stellite balls and pins could be recycled to a source manufacturer rather than disposed of in a low-level burial site. The cost savings to the utility was on the order of $200,000 with a gross savings of $400,000 in savings in burial site charges. A second advantage of the recycling of the stellite pins and rollers was a reduction in control in radioactive waste shipments.

  3. Development of source term evaluation method for Korean Next Generation Reactor(III)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Jae; Park, Jin Baek; Lee, Yeong Il; Song, Min Cheonl; Lee, Ho Jin [Korea Advanced Institue of Science and Technology, Taejon (Korea, Republic of)

    1998-06-15

    This project had investigated irradiation characteristics of MOX fuel method to predict nuclide concentration at primary and secondary coolant using a core containing 100% of all MOX fuel and development of source term evaluation tool. In this study, several prediction methods of source term are evaluated. Detailed contents of this project are : an evaluation of model for nuclear concentration at Reactor Coolant System, evaluation of primary and secondary coolant concentration of reference Nuclear Power Plant using purely MOX fuel, suggestion of source term prediction method of NPP with a core using MOX fuel.

  4. Source term model evaluations for the low-level waste facility performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S.; Su, S.I. [North Carolina State Univ., Raleigh, NC (United States)

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  5. Development of source term evaluation method for Korean Next Generation Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keon Jae; Cheong, Jae Hak; Park, Jin Baek; Kim, Guk Gee [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-10-15

    This project had investigate several design features of radioactive waste processing system and method to predict nuclide concentration at primary coolant basic concept of next generation reactor and safety goals at the former phase. In this project several prediction methods of source term are evaluated conglomerately and detailed contents of this project are : model evaluation of nuclide concentration at Reactor Coolant System, evaluation of primary and secondary coolant concentration of reference Nuclear Power Plant(NPP), investigation of prediction parameter of source term evaluation, basic parameter of PWR, operational parameter, respectively, radionuclide removal system and adjustment values of reference NPP, suggestion of source term prediction method of next generation NPP.

  6. Effect of In-Vessel Retention Strategies under Postulated SGTR Accidents of OPR1000

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Wonjun; Lee, Yongjae; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of); Kim, Hwan-Yeol; Park, Rae-Joon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, MELCOR code was used to simulate the severe accident of the OPR1000. MELCOR code is computer code which enables to simulate the progression of the severe accident for light water reactors. It has been developed by Sandia National Laboratories for plant risk assessment and source term analysis since 1982. According to the probabilistic safety analysis (PSA) Level 1 of OPR1000, typical severe accident scenarios of high probability of a transition to severe accident for OPR1000 were identified as Small Break Loss of Coolant Accident (SBLOCA), Station Black out (SBO), Total Loss of Feed Water (TLOFW), and Steam Generator Tube Rupture. While the first three accidents are expected to result in the generation and transportation of the radioactive nuclides within the containment building as consequence of the core damage and subsequent reactor pressure vessel (RPV) failure, the latter accident scenario may be progressed with possible direct release of the radioactive nuclides to the environment by bypassing the containment building. Thus it is of significance to investigate the SGTR accident with a sophisticated severe accident code. This code can simulate the whole phenomena of a severe accident such as thermal-hydraulic response, core heat-up, oxidation and relocation, and fission product release and transport. Thus many researchers have used MELCOR in severe accident studies. In this study, in-vessel retention strategies were applied for postulated SGTR accidents. Mitigation effect and adverse effect of in-vessel strategies was studied in aspect of RPV failure, fission product release and containment thermal-hydraulic and hydrogen behavior. Base case of SGTR accident and three mitigation cases were simulated using MELCOR code 1.8.6. For each mitigation cases, mitigation effect and adverse effect were investigated. Conclusions can be summarized as follows: (1) RPV failure of SGTR base case occurred at 5.62 hours and fission product of RCS released to

  7. 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.

  8. Long-term assessment of airborne radiocesium after the Fukushima nuclear accident. Re-suspension from bare soil and forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, Mizuo [Japan Meteorological Agency (JMA), Ibaraki (Japan). Meteorological Research Inst. (MRI); RIKEN Advanced Institute for Computational Science (AICS), Hyogo (Japan); Ishizuka, Masahide [Kagawa Univ. (Japan). Faculty of Engineering; Igarashi, Yasuhito [Japan Meteorological Agency (JMA), Ibaraki (Japan). Meteorological Research Inst. (MRI); Kita, Kazuyuki [Ibaraki Univ. (Japan). Faculty of Science; Yoshikawa, Chisato [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa (Japan); Inatsu, Masaru [Hokkaido Univ., Sapporo (Japan). Faculty of Science

    2016-07-01

    The long-term effect of {sup 137}Cs re-suspension from contaminated soil and forests due to the Fukushima nuclear accident has been quantitatively assessed by numerical simulation, a field experiment on dust emission flux in a contaminated area (town of Namie, Fukushima prefecture), and air concentration measurements inside (Namie) and outside (city of Tsukuba, Ibaraki prefecture) the contaminated area. In order to assess the long-term effect, the full year of 2013 was selected to study just after the start of the field experiments. The {sup 137}Cs concentrations at Namie and Tsukuba were approximately 10{sup -1}-1 and 10{sup -2}-10{sup -1} mBq m{sup -3}, respectively. The observed monthly median concentration at Namie was 1 to 2 orders of magnitude larger than that at Tsukuba. This observed difference between the two sites was consistent with the simulated difference, indicating successful modeling of {sup 137}Cs re-suspension and atmospheric transport. The estimated re-suspension rate was approximately 10{sup -6} day{sup -1}, which was significantly lower than the decreasing rate of the ambient gamma dose rate in Fukushima prefecture (10{sup -4}-10{sup -3} day{sup -1}) as a result of radioactive decay, migration in the soil and biota, and decontamination. Consequently, re-suspension contributed negligibly in reducing ground radioactivity. The dust emission model could reproduce the air concentration of {sup 137}Cs in winter, whereas the summer air concentration was underestimated by 1 to 2 orders of magnitude. Re-suspension from forests at a constant rate of 10{sup -7} h{sup -1}, multiplied by the green area fraction, could explain the air concentration of {sup 137}Cs at Namie and its seasonal variation. The simulated contribution of dust re-suspension to the air concentration was 0.7-0.9 in the cold season and 0.2-0.4 in the warm season at both sites; the remainder of the contribution was re-suspension from forest. The re-suspension mechanisms, especially

  9. Long-term assessment of airborne radiocesium after the Fukushima nuclear accident: re-suspension from bare soil and forest ecosystems

    Science.gov (United States)

    Kajino, Mizuo; Ishizuka, Masahide; Igarashi, Yasuhito; Kita, Kazuyuki; Yoshikawa, Chisato; Inatsu, Masaru

    2016-10-01

    The long-term effect of 137Cs re-suspension from contaminated soil and forests due to the Fukushima nuclear accident has been quantitatively assessed by numerical simulation, a field experiment on dust emission flux in a contaminated area (town of Namie, Fukushima prefecture), and air concentration measurements inside (Namie) and outside (city of Tsukuba, Ibaraki prefecture) the contaminated area. In order to assess the long-term effect, the full year of 2013 was selected to study just after the start of the field experiments. The 137Cs concentrations at Namie and Tsukuba were approximately 10-1-1 and 10-2-10-1 mBq m-3, respectively. The observed monthly median concentration at Namie was 1 to 2 orders of magnitude larger than that at Tsukuba. This observed difference between the two sites was consistent with the simulated difference, indicating successful modeling of 137Cs re-suspension and atmospheric transport. The estimated re-suspension rate was approximately 10-6 day-1, which was significantly lower than the decreasing rate of the ambient gamma dose rate in Fukushima prefecture (10-4-10-3 day-1) as a result of radioactive decay, migration in the soil and biota, and decontamination. Consequently, re-suspension contributed negligibly in reducing ground radioactivity. The dust emission model could reproduce the air concentration of 137Cs in winter, whereas the summer air concentration was underestimated by 1 to 2 orders of magnitude. Re-suspension from forests at a constant rate of 10-7 h-1, multiplied by the green area fraction, could explain the air concentration of 137Cs at Namie and its seasonal variation. The simulated contribution of dust re-suspension to the air concentration was 0.7-0.9 in the cold season and 0.2-0.4 in the warm season at both sites; the remainder of the contribution was re-suspension from forest. The re-suspension mechanisms, especially through the forest ecosystems, remain unknown. This is the first study that provides a crude

  10. 福岛核事故源项评价%Radioactive source-term of the Fukushima Nuclear Accident

    Institute of Scientific and Technical Information of China (English)

    林武辉; 陈立奇; 余雯; 马豪; 曾志; 曾实

    2015-01-01

    2011年日本福岛发生的核泄漏对全球环境和社会产生巨大影响,核事故的后果评价与环境修复成为长期而复杂的任务,而源项作为事故分级的重要依据,是后果评价和环境修复的基础.本文从福岛核事故泄漏的核素总量与组成、特征核素谱与其他事件的历史排放水平对比等三方面出发,对福岛核事故的源项进行分析.分析结果表明,福岛核事故泄漏放射性总量大约是切尔诺贝利核事故泄漏总量的10%,不到全球落下灰总量的千分之一,但是福岛核事故是至今为止最为严重的海洋放射性污染核事故.本文还对核事故后处理措施进行评估,针对福岛核事故的环境影响提出一些建议.

  11. Existence and Asymptotic Stability of Solutions for Hyperbolic Differential Inclusions with a Source Term

    Directory of Open Access Journals (Sweden)

    Park Jong Yeoul

    2007-01-01

    Full Text Available We study the existence of global weak solutions for a hyperbolic differential inclusion with a source term, and then investigate the asymptotic stability of the solutions by using Nakao lemma.

  12. Spent Fuel Source Term Calculation of Daya Bay Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    XU; Zhi-long; WAN; Hai-xia; LI; Long; WU; Xiao-chun; SHAO; Jing; LIU; Li-li; ZHANG; Jing

    2013-01-01

    The spent fuel of nuclear power plant should be transported to reprocessing plant for reprocessing after reserving for a period of time.Before that,safety analysis and environmental impact assessment should be carried on to the transportation process,which need radioactive source term calculation and analysis.The task of Daya Bay Nuclear Power Plant spent fuel source term calculation includes estimation of

  13. Backup Sourcing Decisions for Coping with Supply Disruptions under Long-Term Horizons

    OpenAIRE

    Jing Hou; Lijun Sun

    2016-01-01

    This paper studies a buyer’s inventory control problem under a long-term horizon. The buyer has one major supplier that is prone to disruption risks and one backup supplier with higher wholesale price. Two kinds of sourcing methods are available for the buyer: single sourcing with/without contingent supply and dual sourcing. In contingent sourcing, the backup supplier is capacitated and/or has yield uncertainty, whereas in dual sourcing the backup supplier has an incentive to offer output fle...

  14. Fission Product Appearance Rate Coefficients in Design Basis Source Term Determinations - Past and Present

    Science.gov (United States)

    Perez, Pedro B.; Hamawi, John N.

    2017-09-01

    Nuclear power plant radiation protection design features are based on radionuclide source terms derived from conservative assumptions that envelope expected operating experience. Two parameters that significantly affect the radionuclide concentrations in the source term are failed fuel fraction and effective fission product appearance rate coefficients. Failed fuel fraction may be a regulatory based assumption such as in the U.S. Appearance rate coefficients are not specified in regulatory requirements, but have been referenced to experimental data that is over 50 years old. No doubt the source terms are conservative as demonstrated by operating experience that has included failed fuel, but it may be too conservative leading to over-designed shielding for normal operations as an example. Design basis source term methodologies for normal operations had not advanced until EPRI published in 2015 an updated ANSI/ANS 18.1 source term basis document. Our paper revisits the fission product appearance rate coefficients as applied in the derivation source terms following the original U.S. NRC NUREG-0017 methodology. New coefficients have been calculated based on recent EPRI results which demonstrate the conservatism in nuclear power plant shielding design.

  15. Insights into the Societal Risk of Nuclear Power Plant Accidents.

    Science.gov (United States)

    Denning, Richard; Mubayi, Vinod

    2017-01-01

    The elements of societal risk from a nuclear power plant accident are clearly illustrated by the Fukushima accident: land contamination, long-term relocation of large numbers of people, loss of productive farm area, loss of industrial production, and significant loss of electric capacity. NUREG-1150 and other studies have provided compelling evidence that the individual health risk of nuclear power plant accidents is effectively negligible relative to other comparable risks, even for people living in close proximity to a plant. The objective of this study is to compare the societal risk of nuclear power plant accidents to that of other events to which the public is exposed. We have characterized the monetized societal risk in the United States from major societally disruptive events, such as hurricanes, in the form of a complementary cumulative distribution function. These risks are compared with nuclear power plant risks, based on NUREG-1150 analyses and new MACCS code calculations to account for differences in source terms determined in the more recent SOARCA study. A candidate quantitative societal objective is discussed for potential adoption by the NRC. The results are also interpreted with regard to the acceptability of nuclear power as a major source of future energy supply.

  16. Investigation regarding the long-term security developments in the Swedish nuclear power and the response to the accident at Fukushima; Utredning avseende den laangsiktiga saekerhetsutvecklingen i den svenska kaernkraften och aatgaerder med anledning av olyckan i Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Skaanberg, Lars

    2012-07-01

    Swedish nuclear plants need to continue to work on analysis and actions in the plants, partly to meet the demands of legislation and agreed action plans, and partly due to additional security requirements on account of experiences from the Fukushima Dai-ichi accident, stress tests, security investigations and investigations relating to physical protection. It is also essential to continue with safety improvements to gradually increase margins against unforeseen events in aging plants during long-term operation.

  17. 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....

  18. Backup Sourcing Decisions for Coping with Supply Disruptions under Long-Term Horizons

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2016-01-01

    Full Text Available This paper studies a buyer’s inventory control problem under a long-term horizon. The buyer has one major supplier that is prone to disruption risks and one backup supplier with higher wholesale price. Two kinds of sourcing methods are available for the buyer: single sourcing with/without contingent supply and dual sourcing. In contingent sourcing, the backup supplier is capacitated and/or has yield uncertainty, whereas in dual sourcing the backup supplier has an incentive to offer output flexibility during disrupted periods. The buyer’s expected cost functions and the optimal base-stock levels using each sourcing method under long-term horizon are obtained, respectively. The effects of three risk parameters, disruption probability, contingent capacity or uncertainty, and backup flexibility, are examined using comparative studies and numerical computations. Four sourcing methods, namely, single sourcing with contingent supply, dual sourcing, and single sourcing from either of the two suppliers, are also compared. These findings can be used as a valuable guideline for companies to select an appropriate sourcing strategy under supply disruption risks.

  19. Development of safety analysis technology for LMR; development of safety analysis technology for LMR/ development of radioactive source terms in liquid metal reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kamg, Chang Sun; Song, Jae Hyuk; Cho, Young Ho; Go, Hyun Seok; Lee, Young Wook; Jang, Mee [Seoul National Univ., Seoul (Korea)

    2002-05-01

    PRISM source term is reviewed that had much influence on development of KALIMER. A series of experiments and simulations made in many countries are studied and source terms for liquid metal reactors except for PRISM are also reviewed. Thus, KALIMER HCDA source term is determined reasonably and conservatively. Sodium pool fire and sodium spray fire are selected as HCDA scenarios for performance analysis for KALIMER containment dome. Performance analysis for KALIMER containment dome was carried out using CONTAIN-LMR code. Comparing code calculation results with containment design parameters, we determined whether KALIMER containment dome would fail or not. The major parameters are peak pressure and peak temperature. Then, using CONTAIN-LMR code and MACCS code, radiation dose at site boundary was calculated. By comparing code calculation results with PAG guideline and 10 CFR limit, radiological consequences for HCDA was evaluated. The performance analysis showed that KALIMER containment could maintain its integrity and achieve its purpose to mitigate accident consequences and prevent release of radioactive materials in case of HCDA. Sodium pool fire caused higher radiation doses than sodium spray fire. But, dose values evaluated for HCDA were much lower than dose limit values for both sodium pool fire and sodium spray fire. 23 refs., 55 figs., 21 tabs. (Author)

  20. Source term balance in a severe storm in the Southern North Sea

    Science.gov (United States)

    van Vledder, Gerbrant Ph.; Hulst, Sander Th. C.; McConochie, Jason D.

    2016-12-01

    This paper presents the results of a wave hindcast of a severe storm in the Southern North Sea to verify recently developed deep and shallow water source terms. The work was carried out in the framework of the ONR funded NOPP project (Tolman et al. 2013) in which deep and shallow water source terms were developed for use in third-generation wave prediction models. These deep water source terms for whitecapping, wind input and nonlinear interactions were developed, implemented and tested primarily in the WAVEWATCH III model, whereas shallow water source terms for depth-limited wave breaking and triad interactions were developed, implemented and tested primarily in the SWAN wave model. So far, the new deep-water source terms for whitecapping were not fully tested in shallow environments. Similarly, the shallow water source terms were not yet tested in large inter-mediate depth areas like the North Sea. As a first step in assessing the performance of these newly developed source terms, the source term balance and the effect of different physical settings on the prediction of wave heights and wave periods in the relatively shallow North Sea was analysed. The December 2013 storm was hindcast with a SWAN model implementation for the North Sea. Spectral wave boundary conditions were obtained from an Atlantic Ocean WAVEWATCH III model implementation and the model was driven by hourly CFSR wind fields. In the southern part of the North Sea, current and water level effects were included. The hindcast was performed with five different settings for whitecapping, viz. three Komen type whitecapping formulations, the saturation-based whitecapping by Van der Westhuysen et al. (2007) and the recently developed ST6 whitecapping as described by Zieger et al. (2015). Results of the wave hindcast were compared with buoy measurements at location K13 collected by the Dutch Ministry of Transport and Public Works. An analysis was made of the source term balance at three locations, the deep

  1. Temporal Statistic of Traffic Accidents in Turkey

    Science.gov (United States)

    Erdogan, S.; Yalcin, M.; Yilmaz, M.; Korkmaz Takim, A.

    2015-10-01

    Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  2. TEMPORAL STATISTIC OF TRAFFIC ACCIDENTS IN TURKEY

    Directory of Open Access Journals (Sweden)

    S. Erdogan

    2015-10-01

    Full Text Available Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  3. Source Term Model for Vortex Generator Vanes in a Navier-Stokes Computer Code

    Science.gov (United States)

    Waithe, Kenrick A.

    2004-01-01

    A source term model for an array of vortex generators was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the side force created by a vortex generator vane. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on the local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low profile vortex generator vane on a flat plate. In addition, the model was compared to experimental data of an S-duct with 22 co-rotating, low profile vortex generators. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator on a flat plate without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream-wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data. The peak vorticity and its location were also predicted very well when compared to numerical simulations and experimental data. The circulation predicted by the source term model matches the prediction of the numerical simulation. The source term model predicted the engine fan face distortion and total pressure recovery of the S-duct with 22 co-rotating vortex generators very well. The source term model allows a researcher to quickly investigate different locations of individual or a row of vortex generators. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

  4. Potential health risks from postulated accidents involving the Pu-238 RTG (radioisotope thermoelectric generator) on the Ulysses solar exploration mission

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, M. (California Univ., Davis, CA (USA)); Nelson, R.C. (EG and G Idaho, Inc., Idaho Falls, ID (USA)); Bollinger, L. (Air Force Inspection and Safety Center, Kirtland AFB, NM (USA)); Hoover, M.D. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (USA). Inhalation Toxicology Research Inst.); Templeton, W. (Pacific Northwest Lab., Richland, WA (USA)); Anspaugh, L. (Lawren

    1990-11-02

    Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later times after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher. 83 refs.

  5. Accident Generated Particulate Materials and Their Characteristics -- A Review of Background Information

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, S. L.

    1982-05-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of the amount of radioactive particulate material initially airborne (source term) during accidents. Pacific Northwest Laboratory (PNL) has surveyed the literature, gathering information on the amount and size of these particles that has been developed from limited experimental work, measurements made from operational accidents, and known aerosol behavior. Information useful for calculating both liquid and powder source terms is compiled in this report. Potential aerosol generating events discussed are spills, resuspension, aerodynamic entrainment, explosions and pressurized releases, comminution, and airborne chemical reactions. A discussion of liquid behavior in sprays, sparging, evaporation, and condensation as applied to accident situations is also included.

  6. Decontamination tests in the recreational areas affected by the Chernobyl accident: efficiency of decontamination and long-term stability of the effects

    DEFF Research Database (Denmark)

    Ramzaev, V.; Barkovsky, A.; Mishine, A.

    2013-01-01

    in forest-grassland surroundings. The sites are located on the territory of the Bryansk region (Russia) at a distance of about 180 km north-east of the Chernobyl Nuclear Power Plant. Before intervention began, the inventory of 137Cs in soil was determined at a level of 1000 kBq m-2. The collaborative...... of the Fukushima accident....

  7. Identifying Patterns in the Weather of Europe for Source Term Estimation

    Science.gov (United States)

    Klampanos, Iraklis; Pappas, Charalambos; Andronopoulos, Spyros; Davvetas, Athanasios; Ikonomopoulos, Andreas; Karkaletsis, Vangelis

    2017-04-01

    During emergencies that involve the release of hazardous substances into the atmosphere the potential health effects on the human population and the environment are of primary concern. Such events have occurred in the past, most notably involving radioactive and toxic substances. Examples of radioactive release events include the Chernobyl accident in 1986, as well as the more recent Fukushima Daiichi accident in 2011. Often, the release of dangerous substances in the atmosphere is detected at locations different from the release origin. The objective of this work is the rapid estimation of such unknown sources shortly after the detection of dangerous substances in the atmosphere, with an initial focus on nuclear or radiological releases. Typically, after the detection of a radioactive substance in the atmosphere indicating the occurrence of an unknown release, the source location is estimated via inverse modelling. However, depending on factors such as the spatial resolution desired, traditional inverse modelling can be computationally time-consuming. This is especially true for cases where complex topography and weather conditions are involved and can therefore be problematic when timing is critical. Making use of machine learning techniques and the Big Data Europe platform1, our approach moves the bulk of the computation before any such event taking place, therefore allowing for rapid initial, albeit rougher, estimations regarding the source location. Our proposed approach is based on the automatic identification of weather patterns within the European continent. Identifying weather patterns has long been an active research field. Our case is differentiated by the fact that it focuses on plume dispersion patterns and these meteorological variables that affect dispersion the most. For a small set of recurrent weather patterns, we simulate hypothetical radioactive releases from a pre-known set of nuclear reactor locations and for different substance and temporal

  8. Bayesian estimation of a source term of radiation release with approximately known nuclide ratios

    Science.gov (United States)

    Tichý, Ondřej; Šmídl, Václav; Hofman, Radek

    2016-04-01

    We are concerned with estimation of a source term in case of an accidental release from a known location, e.g. a power plant. Usually, the source term of an accidental release of radiation comprises of a mixture of nuclide. The gamma dose rate measurements do not provide a direct information on the source term composition. However, physical properties of respective nuclide (deposition properties, decay half-life) can be used when uncertain information on nuclide ratios is available, e.g. from known reactor inventory. The proposed method is based on linear inverse model where the observation vector y arise as a linear combination y = Mx of a source-receptor-sensitivity (SRS) matrix M and the source term x. The task is to estimate the unknown source term x. The problem is ill-conditioned and further regularization is needed to obtain a reasonable solution. In this contribution, we assume that nuclide ratios of the release is known with some degree of uncertainty. This knowledge is used to form the prior covariance matrix of the source term x. Due to uncertainty in the ratios the diagonal elements of the covariance matrix are considered to be unknown. Positivity of the source term estimate is guaranteed by using multivariate truncated Gaussian distribution. Following Bayesian approach, we estimate all parameters of the model from the data so that y, M, and known ratios are the only inputs of the method. Since the inference of the model is intractable, we follow the Variational Bayes method yielding an iterative algorithm for estimation of all model parameters. Performance of the method is studied on simulated 6 hour power plant release where 3 nuclide are released and 2 nuclide ratios are approximately known. The comparison with method with unknown nuclide ratios will be given to prove the usefulness of the proposed approach. This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases

  9. Radioactive material release from a containment vessel during a fire accident

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, S.; Norkus, J.

    2015-02-26

    A methodology is presented to determine the source term for leaks and ruptures of pressurized vessels. The generic methodology is applied to a 9975 Primary Containment Vessel (PCV) which losses containment due to a hypothesized fire accident. The release due to a vessel rupture is approximately two orders of magnitude greater than the release due to a leak.

  10. Radioactive material release from a containment vessel during a fire accident

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, S. [Savannah River Site (SRS), Aiken, SC (United States); Norkus, J. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-02-26

    A methodology is presented to determine the source term for leaks and ruptures of pressurized vessels. The generic methodology is applied to a 9975 Primary Containment Vessel (PCV) which losses containment due to a hypothesized fire accident. The release due to a vessel rupture is approximately two orders of magnitude greater than the release due to a leak.

  11. Finite Element Solutions for the Space Fractional Diffusion Equation with a Nonlinear Source Term

    Directory of Open Access Journals (Sweden)

    Y. J. Choi

    2012-01-01

    Full Text Available We consider finite element Galerkin solutions for the space fractional diffusion equation with a nonlinear source term. Existence, stability, and order of convergence of approximate solutions for the backward Euler fully discrete scheme have been discussed as well as for the semidiscrete scheme. The analytical convergent orders are obtained as O(k+hγ˜, where γ˜ is a constant depending on the order of fractional derivative. Numerical computations are presented, which confirm the theoretical results when the equation has a linear source term. When the equation has a nonlinear source term, numerical results show that the diffusivity depends on the order of fractional derivative as we expect.

  12. Advanced Reactor PSA Methodologies for System Reliability Analysis and Source Term Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, D.; Brunett, A.; Passerini, S.; Grelle, A.; Bucknor, M.

    2017-06-26

    Beginning in 2015, a project was initiated to update and modernize the probabilistic safety assessment (PSA) of the GE-Hitachi PRISM sodium fast reactor. This project is a collaboration between GE-Hitachi and Argonne National Laboratory (Argonne), and funded in part by the U.S. Department of Energy. Specifically, the role of Argonne is to assess the reliability of passive safety systems, complete a mechanistic source term calculation, and provide component reliability estimates. The assessment of passive system reliability focused on the performance of the Reactor Vessel Auxiliary Cooling System (RVACS) and the inherent reactivity feedback mechanisms of the metal fuel core. The mechanistic source term assessment attempted to provide a sequence specific source term evaluation to quantify offsite consequences. Lastly, the reliability assessment focused on components specific to the sodium fast reactor, including electromagnetic pumps, intermediate heat exchangers, the steam generator, and sodium valves and piping.

  13. Modified Predictor-Corrector WAF Method for the Shallow Water Equations with Source Terms

    Directory of Open Access Journals (Sweden)

    Montri Maleewong

    2011-01-01

    Full Text Available A modified predictor-corrector scheme combining with the depth gradient method (DGM and the weighted average flux (WAF method has been presented to solve the one-dimensional shallow water equations with source terms. Approximate solutions in the predictor step are obtained by the DGM with piecewise-linear reconstructions in each cell volume. The source terms can then be calculated directly by these predicted values at the corresponding half-time step. In the corrector step, the TVD version of the WAF method is applied to calculate the numerical fluxes at the same half-time step for each cell face. The accuracy of numerical solutions is shown by applying the method to solve various test cases in both steady and unsteady problems with and without source terms. It shows that the numerical results are in good agreement with the existing analytical solutions as well as experimental data in some test cases.

  14. Source Term Analysis for Reactor Coolant System with Consideration of Fuel Burnup

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yu Jong; Ahn, Joon Gi; Hwang, Hae Ryong [KEPCO EnC, Daejeon (Korea, Republic of)

    2015-10-15

    The radiation source terms in reactor coolant system (RCS) of pressurized water reactor (PWR) are basic design information for ALARA design such as radiation protection and shielding. Usually engineering companies own self-developed computer codes to estimate the source terms in RCS. DAMSAM and FIPCO are the codes developed by engineering companies. KEPCO E and C has developed computer code, RadSTAR, for use in the Radiation Source Term Analysis for Reactor coolant system during normal operation. The characteristics of RadSTAR are as follows. (1) RadSTAR uses fuel inventory data calculated by ORIGEN, such as ORIGEN2 or ORIGEN-S to consider effects of the fuel burnup. (2) RadSTAR estimates fission products by using finite differential method and analytic method to minimize numerical error. (3) RadSTAR enhances flexibility by adding the function to build the nuclide data library (production pathway library) for user-defined nuclides from ORIGEN data library. (4) RadSTAR consists of two modules. RadSTAR-BL is to build the nuclide data library. RadSTAR-ST is to perform numerical analysis on source terms. This paper includes descriptions on the numerical model, the buildup of nuclide data library, and the sensitivity analysis and verification of RadSTAR. KEPCO E and C developed RadSTAR to calculate source terms in RCS during normal operation. Sensitivity analysis and accuracy verification showed that RadSTAR keeps stability at Δt of 0.1 day and gives more accurate results in comparison with DAMSAM. After development, RadSTAR will replace DAMSAM. The areas, necessary to further development of RadSTAR, are addition of source term calculations for activation products and for shutdown operation.

  15. Non-uniqueness of Admissible Weak Solutions to Compressible Euler Systems with Source Terms

    OpenAIRE

    Luo, Tianwen; Xie, Chunjing; Xin, Zhouping

    2015-01-01

    We consider admissible weak solutions to the compressible Euler system with source terms, which include rotating shallow water system and the Euler system with damping as special examples. In the case of anti-symmetric sources such as rotations, for general piecewise Lipschitz initial densities and some suitably constructed initial momentum, we obtain infinitely many global admissible weak solutions. Furthermore, we construct a class of finite-states admissible weak solutions to the Euler sys...

  16. A study of numerical methods for hyperbolic conservation laws with stiff source terms

    Science.gov (United States)

    Leveque, R. J.; Yee, H. C.

    1990-01-01

    In the present study of the behavior of typical numerical methods in the case of a model advection equation having a parameter-dependent source term, two approaches to the incorporation of the source terms are used: MacCormack-type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. The latter are found to perform slightly better. The model scalar equation is used to show that the incorrectness of the propagation speeds of discontinuities observed in the stiff case is due to the introduction of nonequilibrium values through numerical dissipation in the advection step.

  17. Contribution of the Exposure Pathways After a Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joeun; Hwang, Wontae; Han, Moonhee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jae, Moosung [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    A radiological dose assessment calculates the amount of radiation energy absorbed by a potentially exposed individual as a result of a specific exposure. Public can be exposure from several exposure pathways. External doses occur when the body is exposed to radioactive material outside the body. When making the emergency preparedness for severe accident from NPPs, therefore, we need to have comprehension about those exposure pathways. Thus, in this study, an evaluation of external and internal dose from radioactive materials during severe accident was performed to find out exposure pathway from which the dose has the highest value for several radionuclides. The basic study to make out the relation between exposure pathways and dose from them was performed. In the emergency phase, the most affecting nuclide type on public was noble gas, especially {sup 133}Xe, and the dominant exposure pathway was could shine. Also, in the long term-phase, the most affecting nuclide type on public was fission product, especially {sup 90}Sr, and the dominant exposure pathway was water ingestion. The information of the dose composition from exposure pathway obtained in this study might be basic data for making emergency preparedness plan for severe accident. In the future, assessment of the source term is expected to enhance the reliability of dose assessment during severe accident.

  18. Second Order Fluid Glow Discharge Model Sustained by Different Source Terms%Second Order Fluid Glow Discharge Model Sustained by Different Source Terms

    Institute of Scientific and Technical Information of China (English)

    D. GUENDOUZ; A. HAMID; A. HENNAD

    2011-01-01

    Behavior of charged particles in a DC low pressure glow discharge is studied. The electric properties of the glow discharge in argon, maintained by a constant source term with uni- form electron and ion generation, between two plane electrodes or by secondary electron emission at the cathode, are determined. A fluid model is used to solve self-consistently the first three moments of the Boltzmann equation coupled with the Poisson equation. The stationary spatial distribution of the electron and ion densities, the electric potential, the electric field, and the electron energy, in a two-dimensional (2D) configuration, are presented.

  19. Refined Source Terms in WAVEWATCH III with Wave Breaking and Sea Spray Forecasts

    Science.gov (United States)

    2015-09-30

    shallow water outside the surf zone. After careful testing within a comprehensive suite of test bed cases, these refined source terms will be...including significant wave height, wave periods, wave train evolution, breaking wave probabilities, spectral crest length per unit area distributions...formulating the breaking strength b(k) in terms of the square root of the normalised saturation above a threshold, the Λ(k) values are obtained from

  20. Using Reactive Transport Modeling to Evaluate the Source Term at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Y. Chen

    2001-12-19

    The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses speciation-solubility modeling tools and assumes pure phases of radioelements control their solubility. This assumption may not reflect reality, as most radioelements (except for U) may not form their own pure phases. As a result, solubility limits predicted using the conventional approach are several orders of magnitude higher then the concentrations of radioelements measured in spent fuel dissolution experiments. This paper presents the author's attempt of using a non-conventional approach to evaluate source term of radionuclide release for Yucca Mountain. Based on the general reactive-transport code AREST-CT, a model for spent fuel dissolution and secondary phase precipitation has been constructed. The model accounts for both equilibrium and kinetic reactions. Its predictions have been compared against laboratory experiments and natural analogues. It is found that without calibrations, the simulated results match laboratory and field observations very well in many aspects. More important is the fact that no contradictions between them have been found. This provides confidence in the predictive power of the model. Based on the concept of Np incorporated into uranyl minerals, the model not only predicts a lower Np source-term than that given by conventional Np solubility models, but also produces results which are consistent with laboratory measurements and observations. Moreover, two hypotheses, whether Np enters tertiary uranyl minerals or not, have been tested by comparing model predictions against laboratory observations, the results favor the former. It is concluded that this non-conventional approach of source term evaluation not only eliminates over-conservatism in conventional solubility approach to some extent, but also gives a realistic representation of the system of interest, which is a prerequisite for truly understanding the long-term

  1. NKS-R ExCoolSe mid-term report KTH severe accidents research relevant to the NKS-ExCoolSe project[KTH = Royal Institute of Technology, Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Hyun Sun Park; Truc-Nam Dinh [Royal Inst. of Technology (Sweden)

    2006-04-15

    The present mid-term progress report is prepared on the recent results from the KTH severe accident research program relevant to the objective of the ExCoolSe project sponsored by the NKS-R program. The previous PRE-MELT-DEL project at KTH sponsored by NKS provided an extensive assessment on the remaining issues of severe accidents in general and suggested the key issues to be resolved such as coolability and steam explosion energetics in ex-vessel which became a backbone of the ExCoolSe project in NKS. The EXCOOLSE project has been integrated with, and leveraged on, parallel research program at KTH on severe accident phenomena the MSWI project which is funded by the APRI program, SKI in Sweden and HSK in Switzerland and produced more understanding of the key remaining issues. During last year, the critical assessment of the existing knowledge and current SAMG and designs of Nordic BWRs identified the research focus and initiated the new series of research activities toward the resolution of the key remaining issues specifically pertaining to the Nordic BWRs.(au)

  2. Quantifying sediment source contributions in coastal catchments impacted by the Fukushima nuclear accident with carbon and nitrogen elemental concentrations and stable isotope ratios

    Science.gov (United States)

    Laceby, J. Patrick; Huon Huon, Sylvain; Onda, Yuichi; Evrard, Olivier

    2016-04-01

    The Fukushima Dai-ichi Nuclear Power Plant accidental release of radioactive contaminants resulted in the significant fallout of radiocesium over several coastal catchments in the Fukushima Prefecture. Radiocesium, considered to be the greatest risk to the short and long term health of the local community, is rapidly bound to fine soil particles and thus is mobilized and transported during soil erosion and runoff processes. As there has been a broad-scale decontamination of rice paddy fields and rural residential areas in the contaminated region, one important long term question is whether there is, or may be, a downstream transfer of radiocesium from forests that covered over 65% of the most contaminated region. Accordingly, carbon and nitrogen elemental concentrations and stable isotope ratios are used to determine the relative contributions of forests and rice paddies to transported sediment in three contaminated coastal catchments. Samples were taken from the three main identified sources: cultivated soils (rice paddies and fields, n=30), forest soils (n=45), and subsoils (channel bank and decontaminated soils, n = 25). Lag deposit sediment samples were obtained from five sampling campaigns that targeted the main hydrological events from October 2011 to October 2014. In total, 86 samples of deposited sediment were analyzed for particulate organic matter elemental concentrations and isotope ratios, 24 from the Mano catchment, 44 from the Niida catchment, and 18 from the Ota catchment. Mann-Whitney U-tests were used to examine the source discrimination potential of this tracing suite and select the appropriate tracers for modelling. The discriminant tracers were modelled with a concentration-dependent distribution mixing model. Preliminary results indicate that cultivated sources (predominantly rice paddies) contribute disproportionately more sediment per unit area than forested regions in these contaminated catchments. Future research will examine if there are

  3. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    Science.gov (United States)

    Hall, Matthew L.; Bavelier, Daphne

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory--perception, encoding, and recall--in this effect. The present study…

  4. Hölder-type approximation for the spatial source term of a backward heat equation

    DEFF Research Database (Denmark)

    Dang, Duc Trong; Mach, Minh Nguyet; Pham, Ngoc Dinh Alain;

    2010-01-01

    the function $\\varphi$ and the final temperature $g(x,y)$ are given approximately. The problem is severely ill-posed. Using an interpolation method and the truncated Fourier series, we construct a regularized solution for the source term $f(x,y)$. Our approximation gives the H\\"older-type error estimates...

  5. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    Science.gov (United States)

    Hall, Matthew L.; Bavelier, Daphne

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory--perception, encoding, and recall--in this effect. The present study…

  6. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE LOANS AND GRANTS PRIMARILY FOR REAL ESTATE PURPOSES RURAL HOUSING LOANS AND GRANTS Rural Housing... 7 Agriculture 12 2010-01-01 2010-01-01 false Rates, terms, and source of funds. 1822.268 Section 1822.268 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING...

  7. POINTWISE AND UPWIND DISCRETIZATIONS OF SOURCE TERMS IN OPEN-CHANNEL FLOOD ROUTING

    Institute of Scientific and Technical Information of China (English)

    MENG Jian; CAO Zhi-xian; CARLING Paul A.

    2006-01-01

    Upwind algorithms are becoming progressively popular for river flood routing due to their capability of resolving trans-critical flow regimes. For consistency, these algorithms suggest natural upwind discretization of the source term, which may be essential for natural channels with irregular geometry. Yet applications of these upwind algorithms to natural river flows are rare, and in such applications the traditional and simpler pointwise, rather than upwind discretization of the source term is used. Within the framework of a first-order upwind algorithm, this paper presents a comparison of upwind and pointwise discretizations of the source term. Numerical simulations were carried out for a selected irregular channel comprising a pool-riffle sequence in the River Lune, England with observed data. It is shown that the impact of pointwise discretization, compared to the upwind, is appreciable mainly in flow zones with the Froude number closer to or larger than unity. The discrepancy due to pointwise and upwind discretizations of the source term is negligible in flow depth and hence in water surface elevation, but well manifested in mean velocity and derived flow quantities. Also the occurrence of flow reversal and equalisation over the pool-riffle sequence in response to increasing discharges is demonstrated.

  8. Developmental and social factors in Nigerian children's accidents.

    Science.gov (United States)

    Pfeffer, K

    1991-01-01

    Accidents to children are discussed in terms of developmental and social factors in Nigeria. The types of accidents involving children and age trends in accident incidence are reported. Physical, perceptual, cognitive and social development are discussed. Social factors identified are family variables, the physical environment, and attitudes and folk beliefs.

  9. Detection and analysis of black spots with even small accident figures. Contribution to the Seminar on Short-term and Area-wide Evaluation of Safety Measures, Amsterdam, April 19-21, 1982, p. 75-84.

    NARCIS (Netherlands)

    Oppe, S.

    1982-01-01

    In order to detect accident black spots we have to know the probability of an accident for a traffic situation of some kind, or the mean number of accidents for some unit of time. In almost all procedures known to us, the various road locations are treated as isolated spots. With small accident figu

  10. Regulatory Technology Development Plan - Sodium Fast Reactor: Mechanistic Source Term – Trial Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brunett, Acacia J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Denman, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nuclear Engineering Division; Clark, Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nuclear Engineering Division; Denning, Richard S. [Consultant, Columbus, OH (United States)

    2016-10-01

    The potential release of radioactive material during a plant incident, referred to as the source term, is a vital design metric and will be a major focus of advanced reactor licensing. The U.S. Nuclear Regulatory Commission has stated an expectation for advanced reactor vendors to present a mechanistic assessment of the potential source term in their license applications. The mechanistic source term presents an opportunity for vendors to realistically assess the radiological consequences of an incident and may allow reduced emergency planning zones and smaller plant sites. However, the development of a mechanistic source term for advanced reactors is not without challenges, as there are often numerous phenomena impacting the transportation and retention of radionuclides. This project sought to evaluate U.S. capabilities regarding the mechanistic assessment of radionuclide release from core damage incidents at metal fueled, pool-type sodium fast reactors (SFRs). The purpose of the analysis was to identify, and prioritize, any gaps regarding computational tools or data necessary for the modeling of radionuclide transport and retention phenomena. To accomplish this task, a parallel-path analysis approach was utilized, as shown below. One path, led by Argonne and Sandia National Laboratories, sought to perform a mechanistic source term assessment using available codes, data, and models, with the goal to identify gaps in the current knowledge base. The second path, performed by an independent contractor, performed sensitivity analyses to determine the importance of particular radionuclides and transport phenomena in regards to offsite consequences. The results of the two pathways were combined to prioritize gaps in current capabilities.

  11. Low-level radioactive waste source terms for the 1992 integrated data base

    Energy Technology Data Exchange (ETDEWEB)

    Loghry, S L; Kibbey, A H; Godbee, H W; Icenhour, A S; DePaoli, S M

    1995-01-01

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF{sub 6}) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and {open_quotes}other{close_quotes}. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF{sub 6} conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992.

  12. Fusion of chemical, biological, and meteorological observations for agent source term estimation and hazard refinement

    Science.gov (United States)

    Bieringer, Paul E.; Rodriguez, Luna M.; Sykes, Ian; Hurst, Jonathan; Vandenberghe, Francois; Weil, Jeffrey; Bieberbach, George, Jr.; Parker, Steve; Cabell, Ryan

    2011-05-01

    Chemical and biological (CB) agent detection and effective use of these observations in hazard assessment models are key elements of our nation's CB defense program that seeks to ensure that Department of Defense (DoD) operations are minimally affected by a CB attack. Accurate hazard assessments rely heavily on the source term parameters necessary to characterize the release in the transport and dispersion (T&D) simulation. Unfortunately, these source parameters are often not known and based on rudimentary assumptions. In this presentation we describe an algorithm that utilizes variational data assimilation techniques to fuse CB and meteorological observations to characterize agent release source parameters and provide a refined hazard assessment. The underlying algorithm consists of a combination of modeling systems, including the Second order Closure Integrated PUFF model (SCIPUFF), its corresponding Source Term Estimation (STE) model, a hybrid Lagrangian-Eulerian Plume Model (LEPM), its formal adjoint, and the software infrastructure necessary to link them. SCIPUFF and its STE model are used to calculate a "first guess" source estimate. The LEPM and corresponding adjoint are then used to iteratively refine this release source estimate using variational data assimilation techniques. This algorithm has undergone preliminary testing using virtual "single realization" plume release data sets from the Virtual THreat Response Emulation and Analysis Testbed (VTHREAT) and data from the FUSION Field Trials 2007 (FFT07). The end-to-end prototype of this system that has been developed to illustrate its use within the United States (US) Joint Effects Model (JEM) will be demonstrated.

  13. A Systematic Search for Short-term Variability of EGRET Sources

    Science.gov (United States)

    Wallace, P. M.; Griffis, N. J.; Bertsch, D. L.; Hartman, R. C.; Thompson, D. J.; Kniffen, D. A.; Bloom, S. D.

    2000-01-01

    The 3rd EGRET Catalog of High-energy Gamma-ray Sources contains 170 unidentified sources, and there is great interest in the nature of these sources. One means of determining source class is the study of flux variability on time scales of days; pulsars are believed to be stable on these time scales while blazers are known to be highly variable. In addition, previous work has demonstrated that 3EG J0241-6103 and 3EG J1837-0606 are candidates for a new gamma-ray source class. These sources near the Galactic plane display transient behavior but cannot be associated with any known blazers. Although, many instances of flaring AGN have been reported, the EGRET database has not been systematically searched for occurrences of short-timescale (approximately 1 day) variability. These considerations have led us to conduct a systematic search for short-term variability in EGRET data, covering all viewing periods through proposal cycle 4. Six 3EG catalog sources are reported here to display variability on short time scales; four of them are unidentified. In addition, three non-catalog variable sources are discussed.

  14. Predicting the long-term (137)Cs distribution in Fukushima after the Fukushima Dai-ichi nuclear power plant accident: a parameter sensitivity analysis.

    Science.gov (United States)

    Yamaguchi, Masaaki; Kitamura, Akihiro; Oda, Yoshihiro; Onishi, Yasuo

    2014-09-01

    Radioactive materials deposited on the land surface of Fukushima Prefecture from the Fukushima Dai-ichi Nuclear Power Plant explosion is a crucial issue for a number of reasons, including external and internal radiation exposure and impacts on agricultural environments and aquatic biota. Predicting the future distribution of radioactive materials and their fates is therefore indispensable for evaluation and comparison of the effectiveness of remediation options regarding human health and the environment. Cesium-137, the main radionuclide to be focused on, is well known to adsorb to clay-rich soils; therefore its primary transportation mechanism is in the form of soil erosion on the land surface and transport of sediment-sorbed contaminants in the water system. In this study, we applied the Soil and Cesium Transport model, which we have developed, to predict a long-term cesium distribution in the Fukushima area, based on the Universal Soil Loss Equation and simple sediment discharge formulas. The model consists of calculation schemes of soil erosion, transportation and deposition, as well as cesium transport and its future distribution. Since not all the actual data on parameters is available, a number of sensitivity analyses were conducted here to find the range of the output results due to the uncertainties of parameters. The preliminary calculation indicated that a large amount of total soil loss remained in slope, and the residual sediment was transported to rivers, deposited in rivers and lakes, or transported farther downstream to the river mouths. Most of the sediment deposited in rivers and lakes consists of sand. On the other hand, most of the silt and clay portions transported to river were transported downstream to the river mouths. The rate of sediment deposition in the Abukuma River basin was three times as high as those of the other 13 river basins. This may be due to the larger catchment area and more moderate channel slope of the Abukuma River basin

  15. Search for correlated radio and optical events in long-term studies of extragalactic sources

    Science.gov (United States)

    Pomphrey, R. B.; Smith, A. G.; Leacock, R. J.; Olsson, C. N.; Scott, R. L.; Pollock, J. T.; Edwards, P.; Dent, W. A.

    1976-01-01

    For the first time, long-term records of radio and optical fluxes of a large sample of variable extragalactic sources have been assembled and compared, with linear cross-correlation analysis being used to reinforce the visual comparisons. Only in the case of the BL Lac object OJ 287 is the correlation between radio and optical records strong. In the majority of cases there is no evidence of significant correlation, although nine sources show limited or weak evidence of correlation. The results do not support naive extrapolation of the expanding source model. The general absence of strong correlation between the radio and optical regions has important implications for the energetics of events occurring in such sources.

  16. A Methodology for a Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

    Directory of Open Access Journals (Sweden)

    Grezio Anita

    2015-01-01

    Full Text Available We propose a methodological approach for a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA, in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, the approach allows us to consider all possible tsunamigenic sources (seismic events, slides, volcanic eruptions, asteroids, etc.. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis and we demonstrate how the triggering events may induce significant temporary variations in short-term analysis of the tsunami hazard. In two target sites (the city of Naples and the island of Ischia in Italy we prove the feasibility of the TotPTHA methodology in the multi—source case considering near submarine seismic sources and submarine mass failures in the study area. The TotPTHA indicated that the tsunami hazard increases significantly by considering both the potential submarine mass failures and the submarine seismic events. Finally, the importance of the source interactions is evaluated by applying a triggering seismic event that causes relevant changes in the short-term TotPTHA.

  17. Use of open source software in estimating the effects of a severe accident on the Mark II containment; Uso de software de fuente abierta en la estimacion de los efectos de un accidente severo sobre la contencion Mark II

    Energy Technology Data Exchange (ETDEWEB)

    Sainz, E.; Arguelles, R., E-mail: eduardo.sainz@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    Because the spectrum of scenarios of severe accident before which must verify the integrity of the containment can be very broad, it arises here a calculation methodology to estimate the structural response of the containment without incurring in high costs for commercial software licenses, or in times and calculation excessive requirements. The capabilities of computer programs with license of open source, OpenFOAM for CFD calculations and Salome-Meca for thermal and mechanical calculations were tested. The methodology begins of the venting of mass and energy that are postulated inside the container and the values of the thermal and mechanical fields are obtained through the walls. (Author)

  18. 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

  19. Ranking of severe accident research priorities

    Energy Technology Data Exchange (ETDEWEB)

    Schwinges, B. [Gesell Anlagen and Reaktorsicherheit GRS mbH, D-50667 Cologne (Germany); Journeau, C. [CEA Cadarache, DEN STRI LMA, F-13115 St Paul Les Durance (France); Haste, T. [Paul Scherrer Inst, NES LTH, OVGA 312, CH-5232 Villigen (Switzerland); Meyer, L.; Tromm, W. [Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany); Trambauer, K. [GRS mbH, Forschungsgelande, D-85748 Garching (Germany)

    2010-07-01

    The objectives of the SARNET network are to define common research programmes in the field of severe accidents and to develop common computer tools and methodologies for safety assessment in this field. To reach these objectives, one of the work packages, named 'Severe Accident Research Priorities' (SARP), aimed at reviewing and reassessing the priorities of research issues as a basis to harmonize and to re-orient research programmes, to define new ones, and to close - if possible - resolved issues on a common basis. The work was performed in close collaboration with 8 participating institutions, led by GRS, representing technical safety organisations, industry and utilities (IRSN, CEA, EDF, FZK, GRS, KTH, TUS, VTT). This action made use notably of (1) the outcomes of the EURSAFE project in the 5. Framework Programme, i. e. the Phenomena Identification and Ranking Tables (PIRT) on severe accidents, (2) the results of the validation and benchmarking activities on ASTEC, (3) the results of reactor calculations carried out in the other SARNET tasks, and (4) the outcome of the research performed in the three thematic sub-domains of SARNET (corium, containment and source term). The main outcome of EURSAFE was a list of 21 topics which included recommendations for experimental programmes and code developments. This list formed the basis of the work in SARP. Also the methodology applied in EURSAFE to consider both the risk potential and the severe accident issues where large uncertainties still subsist was adopted. The analyses of the progress of research and development activities considered whether (1) any research issue was resolved due to reduction of uncertainties or gain of scientific insights, (2) any new issue had to be added to the list of needed research, (3) any new process or phenomenon had to be included in the general PIRT list taking into account the safety relevance and the lack of knowledge, and (4) any new accident management program has to be

  20. Regional long-term model of radioactivity dispersion and fate in the Northwestern Pacific and adjacent seas: application to the Fukushima Dai-ichi accident.

    Science.gov (United States)

    Maderich, V; Bezhenar, R; Heling, R; de With, G; Jung, K T; Myoung, J G; Cho, Y-K; Qiao, F; Robertson, L

    2014-05-01

    The compartment model POSEIDON-R was modified and applied to the Northwestern Pacific and adjacent seas to simulate the transport and fate of radioactivity in the period 1945-2010, and to perform a radiological assessment on the releases of radioactivity due to the Fukushima Dai-ichi accident for the period 2011-2040. The model predicts the dispersion of radioactivity in the water column and in sediments, the transfer of radionuclides throughout the marine food web, and subsequent doses to humans due to the consumption of marine products. A generic predictive dynamic food-chain model is used instead of the biological concentration factor (BCF) approach. The radionuclide uptake model for fish has as a central feature the accumulation of radionuclides in the target tissue. The three layer structure of the water column makes it possible to describe the vertical structure of radioactivity in deep waters. In total 175 compartments cover the Northwestern Pacific, the East China and Yellow Seas and the East/Japan Sea. The model was validated from (137)Cs data for the period 1945-2010. Calculated concentrations of (137)Cs in water, bottom sediments and marine organisms in the coastal compartment, before and after the accident, are in close agreement with measurements from the Japanese agencies. The agreement for water is achieved when an additional continuous flux of 3.6 TBq y(-1) is used for underground leakage of contaminated water from the Fukushima Dai-ichi NPP, during the three years following the accident. The dynamic food web model predicts that due to the delay of the transfer throughout the food web, the concentration of (137)Cs for piscivorous fishes returns to background level only in 2016. For the year 2011, the calculated individual dose rate for Fukushima Prefecture due to consumption of fishery products is 3.6 μSv y(-1). Following the Fukushima Dai-ichi accident the collective dose due to ingestion of marine products for Japan increased in 2011 by a

  1. Decontamination tests in the recreational areas affected by the Chernobyl accident: efficiency of decontamination and long-term stability of the effects

    DEFF Research Database (Denmark)

    Ramzaev, V.; Barkovsky, A.; Mishine, A.;

    2013-01-01

    The paper provides a review of the decontamination tests and the follow up monitoring program conducted by the Russian and Danish researchers in two recreational areas in the period 1995–2003. The recreational areas Novie Bobovichi and Muravinka consisted of sets of wooden and brick summer houses...... of the Fukushima accident....... in forest-grassland surroundings. The sites are located on the territory of the Bryansk region (Russia) at a distance of about 180 km north-east of the Chernobyl Nuclear Power Plant. Before intervention began, the inventory of 137Cs in soil was determined at a level of 1000 kBq m-2. The collaborative...

  2. A Statistical Description of the Types and Severities of Accidents Involving Tractor Semi-Trailers, Updated Results for 1992-1996

    Energy Technology Data Exchange (ETDEWEB)

    BLOWER,DANIEL F.; CLAUSS,DAVID B.

    1999-10-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. A previous study (SAND93-2580) reviewed the availability of accident data, identified the TIFA (Trucks Involved in Fatal Accidents) as the best source of accident data for accidents involving heavy trucks, and provided statistics on accident data collected between 1980 and 1990. The current study is an extension of the previous work and describes data collected for heavy truck accidents occurring between 1992 and 1996. The TIFA database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports and interviewing responders and witnesses for selected TEA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, effective fire temperature, fire size, fire separation, and fire duration.

  3. A Statistical Description of the Types and Severities of Accidents Involving Tractor Semi-Trailers, Updated Results for 1992-1996

    Energy Technology Data Exchange (ETDEWEB)

    BLOWER,DANIEL F.; CLAUSS,DAVID B.

    1999-10-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. A previous study (SAND93-2580) reviewed the availability of accident data, identified the TIFA (Trucks Involved in Fatal Accidents) as the best source of accident data for accidents involving heavy trucks, and provided statistics on accident data collected between 1980 and 1990. The current study is an extension of the previous work and describes data collected for heavy truck accidents occurring between 1992 and 1996. The TIFA database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports and interviewing responders and witnesses for selected TEA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, effective fire temperature, fire size, fire separation, and fire duration.

  4. Radiation accident grips Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, L.

    1987-11-20

    On 13 September two young scavengers in Goiania, Brazil, removed a stainless steel cylinder from a cancer therapy machine in an abandoned clinic, touching off a radiation accident second only to Chernobyl in its severity. On 18 September they sold the cylinder, the size of a 1-gallon paint can, to a scrap dealer for $25. At the junk yard an employee dismantled the cylinder and pried open the platinum capsule inside to reveal a glowing blue salt-like substance - 1400 curies of cesium-137. Fascinated by the luminescent powder, several people took it home with them. Some children reportedly rubbed in on their bodies like carnival glitter - an eerie image of how wrong things can go when vigilance over radioactive materials lapses. In all, 244 people in Goiania, a city of 1 million in central Brazil, were contaminated. The eventual toll, in terms of cancer or genetic defects, cannot yet be estimated. Parts of the city are cordoned off as radiation teams continue washing down buildings and scooping up radioactive soil. The government is also grappling with the political fallout from the accident.

  5. On the application of subcell resolution to conservation laws with stiff source terms

    Science.gov (United States)

    Chang, Shih-Hung

    1989-01-01

    LeVeque and Yee recently investigated a one-dimensional scalar conservation law with stiff source terms modeling the reacting flow problems and discovered that for the very stiff case most of the current finite difference methods developed for non-reacting flows would produce wrong solutions when there is a propagating discontinuity. A numerical scheme, essentially nonoscillatory/subcell resolution - characteristic direction (ENO/SRCD), is proposed for solving conservation laws with stiff source terms. This scheme is a modification of Harten's ENO scheme with subcell resolution, ENO/SR. The locations of the discontinuities and the characteristic directions are essential in the design. Strang's time-splitting method is used and time evolutions are done by advancing along the characteristics. Numerical experiment using this scheme shows excellent results on the model problem of LeVeque and Yee. Comparisons of the results of ENO, ENO/SR, and ENO/SRCD are also presented.

  6. In-plant source term measurements at Fort Calhoun Station - Unit 1. Topical technical report

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, N.C.; Keller, J.H.; Bunting, R.L.; Motes, B.G.; Croney, S.T.

    1978-07-01

    Data obtained from an in-plant source term measurement program are presented. The objective of this program is to provide operational data that can be used in the generic evaluation of plant system design in the licensing process and for updating of the calculational models used by the NRC staff in their evaluation of radioactive waste management systems for operating pressurized water reactors. A data base is provided for radioisotope inventory in plant systems, radioactive waste management system performance, and source terms for both liquid and gaseous systems. Data presented were obtained at the Fort Calhoun Station - Unit 1, operated by the Omaha Public Power District (OPPD), located at Blair, Nebraska. In-plant measurements were conducted during the time period from August, 1976 through February 1977. This plant is the first of a planned series of six (6) operating PWR's to be studied.

  7. New Source Term Model for the RESRAD-OFFSITE Code Version 3

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Charley [Argonne National Lab. (ANL), Argonne, IL (United States); Gnanapragasam, Emmanuel [Argonne National Lab. (ANL), Argonne, IL (United States); Cheng, Jing-Jy [Argonne National Lab. (ANL), Argonne, IL (United States); Kamboj, Sunita [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Shih-Yew [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-06-01

    This report documents the new source term model developed and implemented in Version 3 of the RESRAD-OFFSITE code. This new source term model includes: (1) "first order release with transport" option, in which the release of the radionuclide is proportional to the inventory in the primary contamination and the user-specified leach rate is the proportionality constant, (2) "equilibrium desorption release" option, in which the user specifies the distribution coefficient which quantifies the partitioning of the radionuclide between the solid and aqueous phases, and (3) "uniform release" option, in which the radionuclides are released from a constant fraction of the initially contaminated material during each time interval and the user specifies the duration over which the radionuclides are released.

  8. Binary Source Microlensing Event OGLE-2016-BLG-0733: Interpretation of a Long-Term Asymmetric Perturbation

    Science.gov (United States)

    Jung, Y. K.; Udalski, A.; Yee, J. C.; Sumi, T.; Gould, A.; Han, C.; Albrow, M. D.; Lee, C.-U.; Bennett, D. P.; Suzuki, D.

    2017-01-01

    In the process of analyzing an observed light curve, one often confronts various scenarios that can mimic the planetary signals causing difficulties in the accurate interpretation of the lens system. In this paper, we present the analysis of the microlensing event OGLE-2016-BLG-0733. The light curve of the event shows a long-term asymmetric perturbation that would appear to be due to a planet. From the detailed modeling of the lensing light curve, however, we find that the perturbation originates from the binarity of the source rather than the lens. This result demonstrates that binary sources with roughly equal-luminosity components can mimic long-term perturbations induced by planets with projected separations near the Einstein ring. The result also represents the importance of the consideration of various interpretations in planet-like perturbations and of high-cadence observations for ensuring the unambiguous detection of the planet.

  9. Piecewise Approximate Analytical Solutions of High-Order Singular Perturbation Problems with a Discontinuous Source Term

    Directory of Open Access Journals (Sweden)

    Essam R. El-Zahar

    2016-01-01

    Full Text Available A reliable algorithm is presented to develop piecewise approximate analytical solutions of third- and fourth-order convection diffusion singular perturbation problems with a discontinuous source term. The algorithm is based on an asymptotic expansion approximation and Differential Transform Method (DTM. First, the original problem is transformed into a weakly coupled system of ODEs and a zero-order asymptotic expansion of the solution is constructed. Then a piecewise smooth solution of the terminal value reduced system is obtained by using DTM and imposing the continuity and smoothness conditions. The error estimate of the method is presented. The results show that the method is a reliable and convenient asymptotic semianalytical numerical method for treating high-order singular perturbation problems with a discontinuous source term.

  10. 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)

  11. Least-squares finite-element method for shallow-water equations with source terms

    Institute of Scientific and Technical Information of China (English)

    Shin-Jye Liang; Tai-Wen Hsu

    2009-01-01

    Numerical solution of shallow-water equations (SWE) has been a challenging task because of its nonlinear hyperbolic nature, admitting discontinuous solution, and the need to satisfy the C-property. The presence of source terms in momentum equations, such as the bottom slope and friction of bed, compounds the difficulties further. In this paper, a least-squares finite-element method for the space discretization and θ-method for the time integration is developed for the 2D non-conservative SWE including the source terms. Advantages of the method include: the source terms can be approximated easily with interpolation functions, no upwind scheme is needed, as well as the resulting system equations is symmetric and positive-definite, therefore, can be solved efficiently with the conjugate gradient method. The method is applied to steady and unsteady flows, subcritical and transcritical flow over a bump, 1D and 2D circular dam-break, wave past a circular cylinder, as well as wave past a hump. Computed results show good C-property, conservation property and compare well with exact solutions and other numerical results for flows with weak and mild gradient changes, but lead to inaccurate predictions for flows with strong gradient changes and discontinuities.

  12. Schematic way to find solution of the outcoupled matter wave with a source term

    Energy Technology Data Exchange (ETDEWEB)

    Prayitno, T. B. [Physics Department, Faculty of Mathematics and Natural Science, Universitas Negeri Jakarta, Jl. Pemuda Rawamangun No. 10, Jakarta, 13220 (Indonesia)

    2013-09-09

    We propose a schematic way to obtain solution of the outcoupled atom laser beam wave function in the presence of a source term where the beam is influenced by gravity. In this case, we only focus on the external potentials inside the region of Bose-Einstein condensate that are generated by electromagnetic source and gravity. Since the evolution of the atom laser beam can be portrayed through the ordinary Schrödinger equation with a source, we are allowed to express the general solution as the superposition of the homogeneous solution and particular solution. With the given external potentials and ansatz solutions, we attain that the obtained energy depends on the parameter constituting to the ratio between the longitudinal frequency and transverse frequency.

  13. Low-level waste disposal performance assessments - Total source-term analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wilhite, E.L.

    1995-12-31

    Disposal of low-level radioactive waste at Department of Energy (DOE) facilities is regulated by DOE. DOE Order 5820.2A establishes policies, guidelines, and minimum requirements for managing radioactive waste. Requirements for disposal of low-level waste emplaced after September 1988 include providing reasonable assurance of meeting stated performance objectives by completing a radiological performance assessment. Recently, the Defense Nuclear Facilities Safety Board issued Recommendation 94-2, {open_quotes}Conformance with Safety Standards at Department of Energy Low-Level Nuclear Waste and Disposal Sites.{close_quotes} One of the elements of the recommendation is that low-level waste performance assessments do not include the entire source term because low-level waste emplaced prior to September 1988, as well as other DOE sources of radioactivity in the ground, are excluded. DOE has developed and issued guidance for preliminary assessments of the impact of including the total source term in performance assessments. This paper will present issues resulting from the inclusion of all DOE sources of radioactivity in performance assessments of low-level waste disposal facilities.

  14. The effect of work accidents on the efficiency of production in the coal sector

    Directory of Open Access Journals (Sweden)

    Yaşar Kasap

    2011-05-01

    Full Text Available In comparison with other sectors, mining is one of the sectors with the highest rates of work accidents. Such accidents negatively affect a country’s economy by wasting domestic resources and causing losses of both labour force and working days. What distinguishes mining from other branches of industry is that its working environments change continually and the working conditions are particularly harsh. Because of the practice of labour-intensive underground production methods, which leads to an increase in risk factors in terms of work accidents, and the fact that coal is a leading resource in meeting the ever-increasing demand for energy, this study investigated how work accidents affected the efficiency of production in the Turkish Hard Coal Enterprise (TTK between 1987 and 2006. Using data envelopment analysis, the overall sources of technical inefficiency in the years examined were determined. The results from this analysis revealed that the overall technical efficiency was as low as 69.7%, particularly as a result of the disaster in 1992; work accidents therefore had a negative effect on production efficiency. The greatest degree of pure technical inefficiency was found to have occurred in the period between 1992 and 2000, when the highest number of work accidents were noted, whilst the greatest degree of scale inefficiency was found to have occurred between 1987 and 1993. Because TTK has a prominent position among institutions and attaches great importance to workers’ health and safety, an increase was noted in efficiency scores after 1993.

  15. Improvement of the following accident dose assessment system (II)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-12-01

    The FADAS and its database have been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and does not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively. 7 refs., 8 figs., 6 tabs. (Author)

  16. Improvement of the following accident dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae; Choi, Young Gil [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1999-12-15

    The FADAS has been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and dose not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively.

  17. Radioactivity impacts of the Fukushima Nuclear Accident on the atmosphere

    Science.gov (United States)

    Lin, W.; Chen, L.; Yu, W.; Ma, H.; Zeng, Z.; Lin, J.; Zeng, S.

    2015-02-01

    The Fukushima Nuclear Accident (FNA) resulted in a large amount of radionuclides released into the atmosphere and dispersed globally, which has greatly raised public concerns. The state of the art for source terms of 19 kinds of radionuclides derived from the FNA was comprehensively collected and compared with levels of the global fallout and the Chernobyl Nuclear Accident (CNA). The atmospheric impacts of the FNA were evaluated from three aspects including radioactive baseline of the atmosphere, the concentration limits in standards and radiological protection. The FNA should not impose significant radiological risk on the public members in the countries excluding Japan. A conceptual scheme of Fukushima-derived radionuclides with physical and physicochemical insights on different temporal-spatial timescales was discussed and illustrated to understand their fates in the atmosphere.

  18. Analysis of Shahid Rajaee hospital administrative data on injuries resulting from car accidents in Shiraz, Iran: 2011–2014 data

    Directory of Open Access Journals (Sweden)

    Mahnaz Yadollahi

    2017-02-01

    Conclusion: Hospital administrative databases of this hospital could be used as reliable sources of information in providing epidemiologic reports of car accidents in terms of severity and outcomes. Improving the quality of recordings at hospital databases is an important initial step towards more comprehensive injury surveillance in Fars, Iran.

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

    Science.gov (United States)

    Krausmann, Elisabeth; Girgin, Serkan

    2016-04-01

    When natural hazards impact industrial facilities that house or process hazardous materials, fires, explosions and toxic releases can occur. This type of accident is commonly referred to as Natech accident. In order to prevent the recurrence of accidents or to better mitigate their consequences, lessons-learned type studies using available accident data are usually carried out. Through post-accident analysis, conclusions can be drawn on the most common damage and failure modes and hazmat release paths, particularly vulnerable storage and process equipment, and the hazardous materials most commonly involved in these types of accidents. These analyses also lend themselves to identifying technical and organisational risk-reduction measures that require improvement or are missing. Industrial accident databases are commonly used for retrieving sets of Natech accident case histories for further analysis. These databases contain accident data from the open literature, government authorities or in-company sources. The quality of reported information is not uniform and exhibits different levels of detail and accuracy. This is due to the difficulty of finding qualified information sources, especially in situations where accident reporting by the industry or by authorities is not compulsory, e.g. when spill quantities are below the reporting threshold. Data collection has then to rely on voluntary record keeping often by non-experts. The level of detail is particularly non-uniform for Natech accident data depending on whether the consequences of the Natech event were major or minor, and whether comprehensive information was available for reporting. In addition to the reporting bias towards high-consequence events, industrial accident databases frequently lack information on the severity of the triggering natural hazard, as well as on failure modes that led to the hazmat release. This makes it difficult to reconstruct the dynamics of the accident and renders the development of

  20. Spurious Behavior of Shock-Capturing Methods: Problems Containing Stiff Source Terms and Discontinuities

    Science.gov (United States)

    Yee, Helen M. C.; Kotov, D. V.; Wang, Wei; Shu, Chi-Wang

    2013-01-01

    The goal of this paper is to relate numerical dissipations that are inherited in high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities. For pointwise evaluation of the source term, previous studies indicated that the phenomenon of wrong propagation speed of discontinuities is connected with the smearing of the discontinuity caused by the discretization of the advection term. The smearing introduces a nonequilibrium state into the calculation. Thus as soon as a nonequilibrium value is introduced in this manner, the source term turns on and immediately restores equilibrium, while at the same time shifting the discontinuity to a cell boundary. The present study is to show that the degree of wrong propagation speed of discontinuities is highly dependent on the accuracy of the numerical method. The manner in which the smearing of discontinuities is contained by the numerical method and the overall amount of numerical dissipation being employed play major roles. Moreover, employing finite time steps and grid spacings that are below the standard Courant-Friedrich-Levy (CFL) limit on shockcapturing methods for compressible Euler and Navier-Stokes equations containing stiff reacting source terms and discontinuities reveals surprising counter-intuitive results. Unlike non-reacting flows, for stiff reactions with discontinuities, employing a time step and grid spacing that are below the CFL limit (based on the homogeneous part or non-reacting part of the governing equations) does not guarantee a correct solution of the chosen governing equations. Instead, depending on the numerical method, time step and grid spacing, the numerical simulation may lead to (a) the correct solution (within the truncation error of the scheme), (b) a divergent solution, (c) a wrong propagation speed of discontinuities solution or (d) other spurious solutions that are solutions of the discretized counterparts but are not solutions of the governing equations

  1. Work Accidents and Professional Diseases

    Directory of Open Access Journals (Sweden)

    Doru Hauptmann

    2009-10-01

    Full Text Available The major accident is defined as “any event occurred, like an emission of dangerous materials or agents, which emerges from uncontrolled evolutions along the exploitation of any objective that leads to the immediate or delayed occurrence of serious dangers with impact over human health or over the environment, inside or outside the objective in which are involved one or more than one dangerous materials”.The dangerous phenomenon is a potential source of harms. In the ambit of industrial risks of accidental origins, this expression more frequently refers to physical phenomena like conflagrations, explosions, toxic gases dispersion, etc.Any accident scenario relates itself to the potential effects at the level of environmental “targets”. In the case of major accidents, we can distinguish the following categories of “targets”: human (employees of the objective, working or resident people in the nearby of the emplacement; the installation or equipments that may stay at the origin of the accidents (dangerous equipments; certain all-important equipments to ensure the safety level of the installation (critical security equipments: control rooms, civil fire brigade headquarters, etc; goods and structures situated in the installation’ environment (ground water, rivers, soil, flora, fauna.

  2. The Multimedia Environmental Pollutant Assessment System (MEPAS){reg_sign}: Source-term release formulations

    Energy Technology Data Exchange (ETDEWEB)

    Streile, G.P.; Shields, K.D.; Stroh, J.L.; Bagaasen, L.M.; Whelan, G.; McDonald, J.P.; Droppo, J.G.; Buck, J.W.

    1996-11-01

    This report is one of a series of reports that document the mathematical models in the Multimedia Environmental Pollutant Assessment System (MEPAS). Developed by Pacific Northwest National Laboratory for the US Department of Energy, MEPAS is an integrated impact assessment software implementation of physics-based fate and transport models in air, soil, and water media. Outputs are estimates of exposures and health risk assessments for radioactive and hazardous pollutants. Each of the MEPAS formulation documents covers a major MEPAS component such as source-term, atmospheric, vadose zone/groundwater, surface water, and health exposure/health impact assessment. Other MEPAS documentation reports cover the sensitivity/uncertainty formulations and the database parameter constituent property estimation methods. The pollutant source-term release component is documented in this report. MEPAS simulates the release of contaminants from a source, transport through the air, groundwater, surface water, or overland pathways, and transfer through food chains and exposure pathways to the exposed individual or population. For human health impacts, risks are computed for carcinogens and hazard quotients for noncarcinogens. MEPAS is implemented on a desktop computer with a user-friendly interface that allows the user to define the problem, input the required data, and execute the appropriate models for both deterministic and probabilistic analyses.

  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.

    1991-01-01

    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.

  4. 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.

  5. Visualization of Traffic Accidents

    Science.gov (United States)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  6. Safety against releases in severe accidents. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, I.; Berg, Oe.; Nonboel, E. [eds.

    1997-12-01

    The work scope of the RAK-2 project has involved research on quantification of the effects of selected severe accident phenomena for Nordic nuclear power plants, development and testing of a computerised accident management support system and data collection and description of various mobile reactors and of different reactor types existing in the UK. The investigations of severe accident phenomena focused mainly on in-vessel melt progression, covering a numerical assessment of coolability of a degraded BWR core, the possibility and consequences of a BWR reactor to become critical during reflooding and the core melt behavior in the reactor vessel lower plenum. Simulant experiments were carried out to investigate lower head hole ablation induced by debris discharge. In addition to the in-vessel phenomena, a limited study on containment response to high pressure melt ejection in a BWR and a comparative study on fission product source term behaviour in a Swedish PWR were performed. An existing computerised accident management support system (CAMS) was further developed in the area of tracking and predictive simulation, signal validation, state identification and user interface. The first version of a probabilistic safety analysis module was developed and implemented in the system. CAMS was tested in practice with Barsebaeck data in a safety exercise with the Swedish nuclear authority. The descriptions of the key features of British reactor types, AGR, Magnox, FBR and PWR were published as data reports. Separate reports were issued also on accidents in nuclear ships and on description of key features of satellite reactors. The collected data were implemented in a common Nordic database. (au) 39 refs.

  7. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Yong; Ahn, Kwang Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

  8. IAEA-MEL case studies. Pt.1. Source terms and transport processes

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, M.S. [International Atomic Energy Agency, Monaco (Monaco). Marine Environmental Laboratory

    1997-12-31

    This IAEA review summarises the nuclide inventory and process-related aspects of investigations at sites which include disposals and dispersions of radioactive waste in the Arctic Seas, N.E. Atlantic Ocean, Far Eastern Seas and the Irish Sea, accidental inputs to the Norwegian Sea and Sea of Okhotsk, releases from weapons test environments in the Pacific Ocean and fallout from the Chernobyl accident, particularly in the Baltic and Black Seas. In many of these cases, monitoring, behavioural and modelling studies have been carried out. The Monaco laboratory is using natural and man-made radionuclides to trace particle flux and sedimentation, particularly in S.E. Asia and the Mediterranean Sea. A perspective on the results of these studies has been maintained in a new and growing marine radioactivity database which will soon be available to Member States. Radiological conclusions can be compared to the recently published results of a coordinated research programme organised by IAEA-MEL on sources of radioactivity in the marine environment and their relative contributions to overall dose assessment from marine radioactivity (the MARDOS project). Finally, some future plans within the IAEA-MEL programme are outlined. For example, the Government of Japan is funding a strategically planned follow-up to the Geosecs programme to update information on open ocean radionuclide distributions. Additional IAEA funds have also been allocated for study of marine inputs of technologically enhanced natural radionuclides from the oil and phosphogypsum industries. The laboratory is also developing and applying in-situ monitoring techniques for continuous and ROV-mounted surveys of radionuclide inventories in water and sediment. The presentation will end with a call for participation in an IAEA Symposium on Marine Pollution, containing various sessions related to tracer and radiological aspects of marine radioactivity, to be held in Monaco in 1998 as part of the United Nations programme

  9. Analysis of source term modeling for low-level radioactive waste performance assessments

    Energy Technology Data Exchange (ETDEWEB)

    Icenhour, A.S.

    1995-03-01

    Site-specific radiological performance assessments are required for the disposal of low-level radioactive waste (LLW) at both commercial and US Department of Energy facilities. This work explores source term modeling of LLW disposal facilities by using two state-of-the-art computer codes, SOURCEI and SOURCE2. An overview of the performance assessment methodology is presented, and the basic processes modeled in the SOURCE1 and SOURCE2 codes are described. Comparisons are made between the two advective models for a variety of radionuclides, transport parameters, and waste-disposal technologies. These comparisons show that, in general, the zero-order model predicts undecayed cumulative fractions leached that are slightly greater than or equal to those of the first-order model. For long-lived radionuclides, results from the two models eventually reach the same value. By contrast, for short-lived radionuclides, the zero-order model predicts a slightly higher undecayed cumulative fraction leached than does the first-order model. A new methodology, based on sensitivity and uncertainty analyses, is developed for predicting intruder scenarios. This method is demonstrated for {sup 137}Cs in a tumulus-type disposal facility. The sensitivity and uncertainty analyses incorporate input-parameter uncertainty into the evaluation of a potential time of intrusion and the remaining radionuclide inventory. Finally, conclusions from this study are presented, and recommendations for continuing work are made.

  10. A Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

    Science.gov (United States)

    Anita, G.; Selva, J.; Laura, S.

    2011-12-01

    We develop a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA), in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, such an innovative approach allows, in principle, to consider all possible tsunamigenic sources, from seismic events, to slides, asteroids, volcanic eruptions, etc. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis. We demonstrate how external triggering events may induce significant temporary variations in the tsunami hazard. Because of this, such effects should always be considered, at least in short-term applications, to obtain unbiased analyses. Finally, we prove the feasibility of the TotPTHA and of the treatment of interaction/cascade effects by applying this methodology to an ideal region with realistic characteristics (Neverland).

  11. An Organizational-Technical Concept to Deal with Open Source Software License Terms

    Directory of Open Access Journals (Sweden)

    Sergius Dyck

    2016-06-01

    Full Text Available Open source software (OSS released under various license terms is widely used as third party libraries in today's software projects. To ensure open source compliance within an organization, a strategic approach to OSS management is needed. As basis for such an approach, we introduce an organizational-technical concept for dealing with the various OSS licenses by using procedural instructions and build automation software. The concept includes the careful consideration of OSS license conditions. The results obtained from this consideration and additional necessary commitments are documented in a so-called license playbook. We introduce procedure instructions enabling a consistent approach for software development using OSS libraries. The procedure instructions are described in a way such that they can be implemented for example for Java projects using the popular build automation tool Apache Maven and the software repository tool Nexus. We give guidance on how to realize such an implementation on basis of automation tools in practice.

  12. ORIGAMI Automator Primer. Automated ORIGEN Source Terms and Spent Fuel Storage Pool Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thompson, Adam B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bowman, Stephen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Joshua L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    Source terms and spent nuclear fuel (SNF) storage pool decay heat load analyses for operating nuclear power plants require a large number of Oak Ridge Isotope Generation and Depletion (ORIGEN) calculations. SNF source term calculations also require a significant amount of bookkeeping to track quantities such as core and assembly operating histories, spent fuel pool (SFP) residence times, heavy metal masses, and enrichments. The ORIGEN Assembly Isotopics (ORIGAMI) module in the SCALE code system provides a simple scheme for entering these data. However, given the large scope of the analysis, extensive scripting is necessary to convert formats and process data to create thousands of ORIGAMI input files (one per assembly) and to process the results into formats readily usable by follow-on analysis tools. This primer describes a project within the SCALE Fulcrum graphical user interface (GUI) called ORIGAMI Automator that was developed to automate the scripting and bookkeeping in large-scale source term analyses. The ORIGAMI Automator enables the analyst to (1) easily create, view, and edit the reactor site and assembly information, (2) automatically create and run ORIGAMI inputs, and (3) analyze the results from ORIGAMI. ORIGAMI Automator uses the standard ORIGEN binary concentrations files produced by ORIGAMI, with concentrations available at all time points in each assembly’s life. The GUI plots results such as mass, concentration, activity, and decay heat using a powerful new ORIGEN Post-Processing Utility for SCALE (OPUS) GUI component. This document includes a description and user guide for the GUI, a step-by-step tutorial for a simplified scenario, and appendices that document the file structures used.

  13. Source term evaluation during seismic events in the Paducah Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Chen, N.C.J.; Schmidt, R.W.; Taleyarkhan, R.P.

    1996-12-30

    The 00 buildings are expected to collapse (per guidance from structure evaluation) during a seismic event in which acceleration level exceeds 0.15g. All roof beams may slip off supports, and collapse. Equipment may slip off from supports and fall onto the floor. The cell floor is also supposed to collapse due to structural instability and distortion due to excessive acceleration forces. Following structure collapse, expansion joints in the process piping and joints between the piping and equipment are expected to fail. Preliminary analysis showed that converters are likely to remain intact. The UF{sub 6} gas released from the break will rapidly interact with moisture in the air to produce UO{sub 2}F{sub 2} and HF with exothermic energy released of {approximately}0.32 MJ/kg of UF{sub 6} reacted. Depending on the degree of mixing between UF{sub 6} gas, its reaction products, air and freon (R-114), there may occur a strong buoyancy force to disperse UO{sub 2}F{sub 2} aerosol particles that are subjected to the gravitational force for settling. Such a chemical reaction will also occur inside the converters. A substantial amount of UF{sub 6} must be stagnated at the bottom of the converters. At the interface between this stagnated UF{sub 6} and air, UF{sub 6} gas will diffuse into the air, undergo the chemical reaction with moisture there, and eventually be released through the break. Furthermore, lubricant oil fire in the building, if it occurs, will enhance the UF{sub 6} release into the atmosphere. The purpose of this study is to evaluate source term (UO{sub 2}F{sub 2} and HF) during such a seismic event. This study takes an approach using multiple steps as follows: (1) Source term evaluation at the break due to mixing between UF{sub 6} and air along with thermal buoyancy induced by chemical reaction energy, (2) Evaluation of additional source term from the converters in which a substantial UF{sub 6} vapor remains, and (3) Source term evaluation with lubricant oil

  14. PBMR radionuclide source term analysis validation based on AVR operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, C.C. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Olivier, L.D. [Independent Nuclear Consultants, Grahamstown (South Africa); Stassen, E.; Reitsma, F. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Merwe, J.J. van der, E-mail: hanno.vdmerwe@pbmr.co.z [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa)

    2010-10-15

    The determination of radionuclide source terms is vital for any reactor design and licensing safety evaluation. This paper provides an overview of the PBMR analysis tools with specific focus on the modelling of mobile and deposited radionuclide source terms within the pressure boundary of a typical pebble-bed high temperature reactor (HTR). The main focus is on the Dust and Activity Migration and Distribution (DAMD) software code system that models the activation, migration and time-dependent distribution of dust and atomic particles in an HTR such as the AVR and PBMR. Since DAMD provides a time-dependent systems integrated model of HTR designs, most of the obvious physical phenomena relevant to source terms are at play. These include the neutron flux, activation cross-sections, radioactive decay, dust production rates, dust impurity levels, dust filter capabilities, dust particle size distributions, thermal-hydraulic parameters influencing the migration and distribution of particles throughout the main power system and subsystems, and helium coolant leakage and make-up rates. At this stage the DAMD calibration and validation is mainly based on the operational data, experiments and measurements made during 21 years of operating life of the AVR. The comparisons of the DAMD results with various AVR measurements provide confidence in the use of DAMD for the PBMR design and safety evaluations. In addition, sensitivity analyses are performed with DAMD to determine the bounding system parameters that drive the migration and distribution of radionuclides. The use of DAMD to evaluate design configurations, e.g. the effect of the introduction and placement of filters on the radionuclide distribution, is also shown. In conclusion, the importance of a systems modelling approach for radionuclide transport and distribution within the pressure boundary of a typical HTR system, is demonstrated. Since the DAMD code system is calibrated and validated against the AVR measurements it

  15. Numerical Dissipation and Wrong Propagation Speed of Discontinuities for Stiff Source Terms

    Science.gov (United States)

    Yee, H. C.; Kotov, D. V.; Sjoegreen, B.

    2012-01-01

    In compressible turbulent combustion/nonequilibrium flows, the constructions of numerical schemes for (a) stable and accurate simulation of turbulence with strong shocks, and (b) obtaining correct propagation speed of discontinuities for stiff reacting terms on coarse grids share one important ingredient - minimization of numerical dissipation while maintaining numerical stability. Here coarse grids means standard mesh density requirement for accurate simulation of typical non-reacting flows. This dual requirement to achieve both numerical stability and accuracy with zero or minimal use of numerical dissipation is most often conflicting for existing schemes that were designed for non-reacting flows. The goal of this paper is to relate numerical dissipations that are inherited in a selected set of high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities as a function of stiffness of the source term and the grid spacing.

  16. 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.

  17. 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.

  18. Lessons Learned Through the Follow-up of the Long-Term Effects of Over-Exposure to an Ir192 Industrial Radiography Source in Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Jalil, A.; Rabbani, G.; Hossain, M. K.; Alam, M. K.; Koddus, A.

    2003-02-24

    An industrial radiographer was accidentally over-exposed while taking the radiograph of weld-joints of gas pipe-lines in 1985 in Bangladesh. Symptoms of high radiation exposure occurred immediately after the accident and skin erythema developed leading to progressive tissue deterioration. The consequences of this over-exposure is being followed up to assess the long-term effects of ionizing radiation on the victim. Progressive tissue deteriorations have already led to multiple surgeries and successive amputations of the finger-tips so far. Lessons learned from this accident are also reported in this paper.

  19. Laser accidents: Being Prepared

    Energy Technology Data Exchange (ETDEWEB)

    Barat, K

    2003-01-24

    The goal of the Laser Safety Officer and any laser safety program is to prevent a laser accident from occurring, in particular an injury to a person's eyes. Most laser safety courses talk about laser accidents, causes, and types of injury. The purpose of this presentation is to present a plan for safety offices and users to follow in case of accident or injury from laser radiation.

  20. Summary of intensive monitoring for radionuclides in fishery products after Fukushima accident and comparison to the results of long term monitoring program in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Ken; Morita, Takami; Shigenobu, Yuya; Takagi, Kaori; Miki, Shizuho; Kaeriyama, Hideki; Ambe, Daisuke; Ono, Tsuneo [National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4, Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648 (Japan)

    2014-07-01

    Monitoring of artificial radionuclides in fishery products started in late 1950's and has over half a century history in Japan. Fisheries Agency (FA), Fisheries Research Agency (FRA) and prefectural organizations have been conducting the monitoring. The intensive monitoring of radioactive material in fishery products started in the late of March 2011 immediately after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident for the coastal area faced to the Pacific Ocean in the eastern area of Japan and for the offshore area. The purpose of this monitoring is to avoid the distribution of fishery products containing radioactive cesium in concentration over the Japanese standard limit (Cs-134+Cs-137: 100 Bq/kg). Japanese monitoring data are opened to public on the FA's and FRA's web page. In this study, we resume the results of intensive monitoring started in 2011 and show the temporal change of concentration of radioactive cesium in fishery product. In Fukushima Prefecture, the ratio of samples exceeding the Japanese standard limit shows a steadily decreasing trend from 53% at Mar.- Jun. 2011 to below 3% at Jul. - Sep. 2013. In other prefectures, the ratio was 6.5% at Mar.- Jun. 2011 and fell gradually, and it has been below to 1% at Jul. - Sep. 2013. In presentation, we show the results of monitoring conducted in the coastal area and deeper water around Japan from long gamma ray measurements with ashed samples by high purified germanium gamma spectrometry. (authors)

  1. 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.

  2. Guide to radiological accident considerations for siting and design of DOE nonreactor nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Elder, J.C.; Graf, J.M.; Dewart, J.M.; Buhl, T.E.; Wenzel, W.J.; Walker, L.J.; Stoker, A.K.

    1986-01-01

    This guide was prepared to provide the experienced safety analyst with accident analysis guidance in greater detail than is possible in Department of Energy (DOE) Orders. The guide addresses analysis of postulated serious accidents considered in the siting and selection of major design features of DOE nuclear facilities. Its scope has been limited to radiological accidents at nonreactor nuclear facilities. The analysis steps addressed in the guide lead to evaluation of radiological dose to exposed persons for comparison with siting guideline doses. Other possible consequences considered are environmental contamination, population dose, and public health effects. Choices of models and parameters leading to estimation of source terms, release fractions, reduction and removal factors, dispersion and dose factors are discussed. Although requirements for risk analysis have not been established, risk estimates are finding increased use in siting of major nuclear facilities, and are discussed in the guide. 3 figs., 9 tabs.

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

    Directory of Open Access Journals (Sweden)

    Rozental Jose de Julio

    2002-01-01

    of Safety Performance and Safety Culture. Accident investigation is the first step toward avoiding future injures and financial losses, by prevention of recur recurrence. On the other hand, accident investigation is also essential for the establishment of the responsibilities and liability for the consequences. This document discuss the main accidents that have happened in the last two decades, in terms of causes, consequences, similarities and lessons learned when sealed sources have been damaged, lost, stolen and abandoned. In considerable majority death and serious injuries were resulted from failures in the safety system for radiation sources and for the security of radioactive materials.

  4. [Accidents with the "paraglider"].

    Science.gov (United States)

    Lang, T H; Dengg, C; Gabl, M

    1988-09-01

    With a collective of 46 patients we show the details and kinds of accidents caused by paragliding. The base for the casuistry of the accidents was a questionnaire which was answered by most of the injured persons. These were questions about the theoretical and practical training, the course of the flight during the different phases, and the subjective point of view of the course of the accident. The patterns of the injuries showed a high incidence of injuries of the spinal column and high risks for the ankles. At the end, we give some advice how to prevent these accidents.

  5. Accidents (FARS) (National)

    Data.gov (United States)

    Department of Transportation — Accident - (1975-current): This data file (NTAD) contains information about crash characteristics and environmental conditions at the time of the crash. There is one...

  6. An analysis of aircraft accidents involving fires

    Science.gov (United States)

    Lucha, G. V.; Robertson, M. A.; Schooley, F. A.

    1975-01-01

    All U. S. Air Carrier accidents between 1963 and 1974 were studied to assess the extent of total personnel and aircraft damage which occurred in accidents and in accidents involving fire. Published accident reports and NTSB investigators' factual backup files were the primary sources of data. Although it was frequently not possible to assess the relative extent of fire-caused damage versus impact damage using the available data, the study established upper and lower bounds for deaths and damage due specifically to fire. In 12 years there were 122 accidents which involved airframe fires. Eighty-seven percent of the fires occurred after impact, and fuel leakage from ruptured tanks or severed lines was the most frequently cited cause. A cost analysis was performed for 300 serious accidents, including 92 serious accidents which involved fire. Personal injury costs were outside the scope of the cost analysis, but data on personnel injury judgements as well as settlements received from the CAB are included for reference.

  7. Toward a Mechanistic Source Term in Advanced Reactors: A Review of Past Incidents, Experiments, and Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Bucknor, Matthew; Brunett, Acacia J.; Grabaskas, David

    2016-04-17

    In 2015, as part of a Regulatory Technology Development Plan (RTDP) effort for sodium-cooled fast reactors (SFRs), Argonne National Laboratory investigated the current state of knowledge of source term development for a metal-fueled, pool-type SFR. This paper provides a summary of past domestic metal-fueled SFR incidents and experiments and highlights information relevant to source term estimations that were gathered as part of the RTDP effort. The incidents described in this paper include fuel pin failures at the Sodium Reactor Experiment (SRE) facility in July of 1959, the Fermi I meltdown that occurred in October of 1966, and the repeated melting of a fuel element within an experimental capsule at the Experimental Breeder Reactor II (EBR-II) from November 1967 to May 1968. The experiments described in this paper include the Run-Beyond-Cladding-Breach tests that were performed at EBR-II in 1985 and a series of severe transient overpower tests conducted at the Transient Reactor Test Facility (TREAT) in the mid-1980s.

  8. The Analytical Repository Source-Term (AREST) model: Description and documentation

    Energy Technology Data Exchange (ETDEWEB)

    Liebetrau, A.M.; Apted, M.J.; Engel, D.W.; Altenhofen, M.K.; Strachan, D.M.; Reid, C.R.; Windisch, C.F.; Erikson, R.L.; Johnson, K.I.

    1987-10-01

    The geologic repository system consists of several components, one of which is the engineered barrier system. The engineered barrier system interfaces with natural barriers that constitute the setting of the repository. A model that simulates the releases from the engineered barrier system into the natural barriers of the geosphere, called a source-term model, is an important component of any model for assessing the overall performance of the geologic repository system. The Analytical Repository Source-Term (AREST) model being developed is one such model. This report describes the current state of development of the AREST model and the code in which the model is implemented. The AREST model consists of three component models and five process models that describe the post-emplacement environment of a waste package. All of these components are combined within a probabilistic framework. The component models are a waste package containment (WPC) model that simulates the corrosion and degradation processes which eventually result in waste package containment failure; a waste package release (WPR) model that calculates the rates of radionuclide release from the failed waste package; and an engineered system release (ESR) model that controls the flow of information among all AREST components and process models and combines release output from the WPR model with failure times from the WPC model to produce estimates of total release. 167 refs., 40 figs., 12 tabs.

  9. In-plant source term measurements at Fort Calhoun Station, Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, N.C.; Bunting, R.L.; Croney, S.T.

    1978-04-01

    The report presents data obtained from an in-plant source term measurement program conducted for the Office of Nuclear Regulatory Research in support of the Effluent Treatment Systems Branch of the Office of Nuclear Reactor Regulation. The objective of this program is to provide operational data that can be used in the generic evaluation of plant system design in the licensing process and for updating of the calculational models used by the NRC staff in their evaluation of radioactive waste management systems for operating pressurized water reactors. A data base is provided for radioisotope inventory in plant systems, radioactive waste management system performance, and source terms for both liquid and gaseous systems. Data presented were obtained at the Fort Calhoun Station-Unit 1, operated by the Omaha Public Power District (OPPD), located at Blair, Nebraska. In-plant measurements were conducted during the time period from August, 1976 through February 1977. This plant is the first of a planned series of six (6) operating PWR's to be studied.

  10. Chernobyl radiocesium in freshwater fish: Long-term dynamics and sources of variation

    Energy Technology Data Exchange (ETDEWEB)

    Sundbom, M. [Uppsala Univ., Dept. of Limnology, Uppsala (Sweden)

    2002-04-01

    The aim of this thesis was to investigate both the long-term temporal pattern and sources of individual variation for radiocesium in freshwater fish. The basis for the study is time series of {sup 137}Cs activity concentrations in fish from three lakes in the area North-west of Uppsala, Sweden that received considerable amounts of {sup 137}Cs from Chernobyl in may 1986. The lakes were Lake Ekholmssjoen, Lake Flatsjoen and Lake Siggeforasjoen, all small forest lakes, but with different morphometrical and chemical characteristics. The data were collected regularly, usually several times per year, during 1986-2000, using consistent methods. More than 7600 fish individuals from 7 species covering wide size ranges and feeding habits were analysed for {sup 137}Cs. For each fish was the length, weight, sex, and often the stomach contend recorded. The evaluation on long-term trends were based on data from all three lakes, while the study on sources of variation evaluated data from Lake Flatsjoen only. (au)

  11. Reference Spent Fuel and Its Source Terms for a Design of Deep Geological Disposal System

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dong Keun

    2005-12-15

    In this study, current status and future trend of domestic spent fuels were analyzed to propose reference spent nuclear fuel. And then, source terms needed for design of a deep geological disposal system were calculated using ORIGEN-ARP. The reference spent fuels selected based on assembly physical dimension, inventory projection, trend of initial enrichment of 235U, discharge burnup are as follows; The 17x17 Korean Optimized Fuel Assembly with initial enrichment of 4.0 wt.% 235U and discharge burnup of 45 GWD/MTU was adopted as a low-burnup representative fuel. For the high-burnup representative fuel, 16x16 Korean Standard Fuel Assembly with initial enrichment of 4.5 wt.% 235U and discharge burnup of 55 GWD/MTU was chosen. CANDU fuel with initial enrichment of 0.711 wt.% 235U and discharge burnup of 7.5 GWD/MTU was also considered. For these reference fuels, decay heat, radiation intensity and spectrum, nuclide concentration, and individual nuclide radioactivity were calculated using ORIGEN-ARP for a disposal system design. It is expected that the source terms estimated in this study will be applied to the disposal system development in the future.

  12. Environmental radiation safety: source term modification by soil aerosols. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Allen, M.D.; Rossignol, E.J.; Cannon, W.C.

    1980-08-01

    The goal of this project is to provide information useful in estimating hazards related to the use of a pure refractory oxide of /sup 238/Pu as a power source in some of the space vehicles to be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere, and to impact with the earth's surface without releasing any plutonium, the possibility that such an event might produce aerosols composed of soil and /sup 238/PuO/sub 2/ cannot be absolutely excluded. This report presents the results of our most recent efforts to measure the degree to which the plutonium aerosol source term might be modified in a terrestrial environment. The five experiments described represent our best effort to use the original experimental design to study the change in the size distribution and concentration of a /sup 238/PuO/sub 2/ aerosol due to coagulation with an aerosol of clay or sandy loam soil.

  13. Long term change in relative contribution of various source regions on the surface ozone over Japan

    Science.gov (United States)

    Nagashima, T.; Sudo, K.; Akimoto, H.; Kurokawa, J.; Ohara, T.

    2011-12-01

    Although the concentrations of O3 precursors over Japan have been decreasing in recent decades, long-term monitoring data shows that the surface concentration of O3 in Japan has increased since the mid-1980s until the present time. As the cause of this recent increase in surface O3 over Japan, the trans-boundary transport of O3 from the outside of Japan have been pointed out and discussed. In particular, transport from East Asian countries whose emissions of the O3 precursors have been greatly increasing recently due to their economic growth is likely a major cause of the observed increase in O3 over Japan. However, the long-term change in other factors that also have an influence on the O3 in Japan, such as the domestic emissions or the background O3, should also be evaluated. Here, we performed a long-term (1980-2005) simulation of the Source-Receptor (S-R) relationship for surface O3 in East Asia by utilizing the tagged tracer method with a global chemical transport model. During this period, emissions of O3 precursors in the model from East Asia, especially from China, have increased more than double, while those from North America have not change so much and those from Europe have decreased. The model simulated the long-term increasing trend in the surface O3 over Japan similar to the observation. The long-term changes of contributions from each source region of O3 showed that the largest contributor to the increasing trend of surface O3 in Japan is the increase of O3 created in planetary boundary layer (PBL) of China which accounts for 35% of the trend, and those of O3 created in PBL of Korean Peninsular and Japan account for 13% and 12%, respectively. The O3 created in free troposphere of China also increased, which account for 4% of the trend. Therefore, almost 40% of recent O3 increase in Japan can be attributed to the increase in the O3 created over China.

  14. Estimating the Duration of Public Concern After the Fukushima Dai-ichi Nuclear Power Station Accident From the Occurrence of Radiation Exposure-Related Terms on Twitter: A Retrospective Data Analysis

    Science.gov (United States)

    2016-01-01

    Background After the Fukushima Dai-ichi Nuclear Power Station accident in Japan on March 11, 2011, a large number of comments, both positive and negative, were posted on social media. Objective The objective of this study was to clarify the characteristics of the trend in the number of tweets posted on Twitter, and to estimate how long public concern regarding the accident continued. We surveyed the attenuation period of the first term occurrence related to radiation exposure as a surrogate endpoint for the duration of concern. Methods We retrieved 18,891,284 tweets from Twitter data between March 11, 2011 and March 10, 2012, containing 143 variables in Japanese. We selected radiation, radioactive, Sievert (Sv), Becquerel (Bq), and gray (Gy) as keywords to estimate the attenuation period of public concern regarding radiation exposure. These data, formatted as comma-separated values, were transferred into a Statistical Analysis System (SAS) dataset for analysis, and survival analysis methodology was followed using the SAS LIFETEST procedure. This study was approved by the institutional review board of Hokkaido University and informed consent was waived. Results A Kaplan-Meier curve was used to show the rate of Twitter users posting a message after the accident that included one or more of the keywords. The term Sv occurred in tweets up to one year after the first tweet. Among the Twitter users studied, 75.32% (880,108/1,168,542) tweeted the word radioactive and 9.20% (107,522/1,168,542) tweeted the term Sv. The first reduction was observed within the first 7 days after March 11, 2011. The means and standard errors (SEs) of the duration from the first tweet on March 11, 2011 were 31.9 days (SE 0.096) for radioactive and 300.6 days (SE 0.181) for Sv. These keywords were still being used at the end of the study period. The mean attenuation period for radioactive was one month, and approximately one year for radiation and radiation units. The difference in mean duration

  15. MELCOR analysis of the TMI-2 accident

    Energy Technology Data Exchange (ETDEWEB)

    Boucheron, E.A.

    1990-01-01

    This paper describes the analysis of the Three Mile Island-2 (TMI-2) standard problem that was performed with MELCOR. The MELCOR computer code is being developed by Sandia National Laboratories for the Nuclear Regulatory Commission for the purpose of analyzing severe accident in nuclear power plants. The primary role of MELCOR is to provide realistic predictions of severe accident phenomena and the radiological source team. The analysis of the TMI-2 standard problem allowed for comparison of the model predictions in MELCOR to plant data and to the results of more mechanistic analyses. This exercise was, therefore valuable for verifying and assessing the models in the code. The major trends in the TMI-2 accident are reasonably well predicted with MELCOR, even with its simplified modeling. Comparison of the calculated and measured results is presented and, based on this comparison, conclusions can be drawn concerning the applicability of MELCOR to severe accident analysis. 5 refs., 10 figs., 3 tabs.

  16. 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.

  17. DUSTMS-D: DISPOSAL UNIT SOURCE TERM - MULTIPLE SPECIES - DISTRIBUTED FAILURE DATA INPUT GUIDE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.

    2006-01-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). Many of these physical processes are influenced by the design of the disposal facility (e.g., how the engineered barriers control infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This has been done and the resulting models have been incorporated into the computer code DUST-MS (Disposal Unit Source Term-Multiple Species). The DUST-MS computer code is designed to model water flow, container degradation, release of contaminants from the wasteform to the contacting solution and transport through the subsurface media. Water flow through the facility over time is modeled using tabular input. Container degradation models include three types of failure rates: (a) instantaneous (all containers in a control volume fail at once), (b) uniformly distributed failures (containers fail at a linear rate between a specified starting and ending time), and (c) gaussian failure rates (containers fail at a rate determined by a mean failure time, standard deviation and gaussian distribution). Wasteform release models include four release mechanisms: (a) rinse with partitioning (inventory is released instantly upon container failure subject to equilibrium partitioning (sorption) with

  18. Fukushima nuclear power plant accident was preventable

    Science.gov (United States)

    Kanoglu, Utku; Synolakis, Costas

    2015-04-01

    On 11 March 2011, the fourth largest earthquake in recorded history triggered a large tsunami, which will probably be remembered from the dramatic live pictures in a country, which is possibly the most tsunami-prepared in the world. The earthquake and tsunami caused a major nuclear power plant (NPP) accident at the Fukushima Dai-ichi, owned by Tokyo Electric Power Company (TEPCO). The accident was likely more severe than the 1979 Three Mile Island and less severe than the Chernobyl 1986 accidents. Yet, after the 26 December 2004 Indian Ocean tsunami had hit the Madras Atomic Power Station there had been renewed interest in the resilience of NPPs to tsunamis. The 11 March 2011 tsunami hit the Onagawa, Fukushima Dai-ichi, Fukushima Dai-ni, and Tokai Dai-ni NPPs, all located approximately in a 230km stretch along the east coast of Honshu. The Onagawa NPP was the closest to the source and was hit by an approximately height of 13m tsunami, of the same height as the one that hit the Fukushima Dai-ichi. Even though the Onagawa site also subsided by 1m, the tsunami did not reach to the main critical facilities. As the International Atomic Energy Agency put it, the Onagawa NPP survived the event "remarkably undamaged." At Fukushima Dai-ichi, the three reactors in operation were shut down due to strong ground shaking. The earthquake damaged all offsite electric transmission facilities. Emergency diesel generators (EDGs) provided back up power and started cooling down the reactors. However, the tsunami flooded the facilities damaging 12 of its 13 EDGs and caused a blackout. Among the consequences were hydrogen explosions that released radioactive material in the environment. It is unfortunately clear that TEPCO and Japan's principal regulator Nuclear and Industrial Safety Agency (NISA) had failed in providing a professional hazard analysis for the plant, even though their last assessment had taken place only months before the accident. The main reasons are the following. One

  19. A note on variational multiscale methods for high-contrast heterogeneous porous media flows with rough source terms

    KAUST Repository

    Calo, Victor M.

    2011-09-01

    In this short note, we discuss variational multiscale methods for solving porous media flows in high-contrast heterogeneous media with rough source terms. Our objective is to separate, as much as possible, subgrid effects induced by the media properties from those due to heterogeneous source terms. For this reason, enriched coarse spaces designed for high-contrast multiscale problems are used to represent the effects of heterogeneities of the media. Furthermore, rough source terms are captured via auxiliary correction equations that appear in the formulation of variational multiscale methods [23]. These auxiliary equations are localized and one can use additive or multiplicative constructions for the subgrid corrections as discussed in the current paper. Our preliminary numerical results show that one can capture the effects due to both spatial heterogeneities in the coefficients (such as permeability field) and source terms (e.g., due to singular well terms) in one iteration. We test the cases for both smooth source terms and rough source terms and show that with the multiplicative correction, the numerical approximations are more accurate compared to the additive correction. © 2010 Elsevier Ltd.

  20. Communication and industrial accidents

    NARCIS (Netherlands)

    As, Sicco van

    2001-01-01

    This paper deals with the influence of organizational communication on safety. Accidents are actually caused by individual mistakes. However the underlying causes of accidents are often organizational. As a link between these two levels - the organizational failures and mistakes - I suggest the conc

  1. Accidents - personal factors

    Energy Technology Data Exchange (ETDEWEB)

    Zaitsev, S.L.; Tsygankov, A.V.

    1982-03-01

    This paper evaluates influence of selected personal factors on accident rate in underground coal mines in the USSR. Investigations show that so-called organizational factors cause from 80 to 85% of all accidents. About 70% of the organizational factors is associated with social, personal and economic features of personnel. Selected results of the investigations carried out in Donbass mines are discussed. Causes of miner dissatisfaction are reviewed: 14% is caused by unsatisfactory working conditions, 21% by repeated machine failures, 16% by forced labor during days off, 14% by unsatisfactory material supply, 16% by hard physical labor, 19% by other reasons. About 25% of miners injured during work accidents are characterized as highly professionally qualified with automatic reactions, and about 41% by medium qualifications. About 60% of accidents is caused by miners with less than a 3 year period of service. About 15% of accidents occurs during the first month after a miner has returned from a leave. More than 30% of accidents occurs on the first work day after a day or days off. Distribution of accidents is also presented: 19% of accidents occurs during the first 2 hours of a shift, 36% from the second to the fourth hour, and 45% occurs after the fourth hour and before the shift ends.

  2. Accident investigation and analysis

    NARCIS (Netherlands)

    Kampen, J. van; Drupsteen, L.

    2013-01-01

    Many organisations and companies take extensive proactive measures to identify, evaluate and reduce occupational risks. However, despite these efforts things still go wrong and unintended events occur. After a major incident or accident, conducting an accident investigation is generally the next ste

  3. Distributed source term analysis, a new approach to nuclear material inventory verification

    CERN Document Server

    Beddingfield, D H

    2002-01-01

    The Distributed Source-Term Analysis (DSTA) technique is a new approach to measuring in-process material holdup that is a significant departure from traditional hold-up measurement methodology. The DSTA method is a means of determining the mass of nuclear material within a large, diffuse, volume using passive neutron counting. The DSTA method is a more efficient approach than traditional methods of holdup measurement and inventory verification. The time spent in performing DSTA measurement and analysis is a fraction of that required by traditional techniques. The error ascribed to a DSTA survey result is generally less than that from traditional methods. Also, the negative bias ascribed to gamma-ray methods is greatly diminished because the DSTA method uses neutrons which are more penetrating than gamma-rays.

  4. Novel Slope Source Term Treatment for Preservation of Quiescent Steady States in Shallow Water Flows

    Directory of Open Access Journals (Sweden)

    Khawar Rehman

    2016-10-01

    Full Text Available This paper proposes a robust method for modeling shallow-water flows and near shore tsunami propagation, applicable for both simple and complex geometries with uneven beds. The novel aspect of the model includes the introduction of a new method for slope source terms treatment to preserve quiescent equilibrium over uneven topographies, applicable to both structured and unstructured mesh systems with equal accuracy. Our model is based on the Godunov-type finite volume numerical approximation. Second-order spatial and temporal accuracy is achieved through high resolution gradient reconstruction and the predictor-corrector method, respectively. The approximate Riemann solver of Harten, Lax, and van Leer with contact wave restoration (HLLC is used to compute fluxes. Comparisons of the model’s results with analytical, experimental, and published numerical solutions show that the proposed method is capable of accurately predicting experimental and real-time tsunami propagation/inundation, and dam-break flows over varying topographies.

  5. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-04-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory.

  6. Long-term Periodicity Analysis of Polarization Variation for Radio Sources

    Indian Academy of Sciences (India)

    Yuhai Yuan

    2011-03-01

    We use the database of University of Michigan Radio Astronomy Observatory (UMRAO) at three radio bands (4.8, 8 and 14.5 GHz) to analyse the long-term polarization variation in search of the possible periodicity. Using the power spectral analysis method (PSA), the Jurkevich method and the discrete correlation function (DCF) method, we find that there are 16 sources lying in periodicity. The results show the astrophysically meaningful periodicity covering 2.1 years to 16.2 years at 4.8 GHz, 2.8 years to 16.3 years at 8 GHz, and 1.8 years to 16.6 years at 14.5 GHz.

  7. 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 ...

  8. Source term and activation calculations for the new TR-FLEX cyclotron for medical applications at HZDR

    Energy Technology Data Exchange (ETDEWEB)

    Konheiser, Joerg [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactor Safety; Ferrari, A. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Radiation Physics; Magin, A. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany); Naumann, B. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Dept. of Radiation Protection and Safety; Mueller, S.E.

    2017-06-01

    The neutron source terms for a proton beam hitting an {sup 18}O-enriched water target were calculated with the radiation transport programs MCNP6 and FLUKA and were compared to source terms for exclusive {sup 18}O(p,n){sup 18}F production. To validate the radiation fields obtained in the simulations, an experimental program has been started using activation samples originally used in reactor dosimetry.

  9. A New Lattice Bhatnagar-Gross-Krook Model for the Convection-Diffusion Equation with a Source Term

    Institute of Scientific and Technical Information of China (English)

    DENG Bin; SHI Bao-Chang; WANG Guang-Chao

    2005-01-01

    @@ A new lattice Bhatnagar-Gross-Krook (LBGK) model for the convection-diffusion equation with a source term is proposed. Unlike the models proposed previously, the present model does not require any additional assumption on the source term. Numerical results are found to be in excellent agreement with the analytical solutions. It is also found that the numerical accuracy of the model is much better than that of the existing models.

  10. The aerosol at Barrow, Alaska: long-term trends and source locations

    Science.gov (United States)

    Polissar, A. V.; Hopke, P. K.; Paatero, P.; Kaufmann, Y. J.; Hall, D. K.; Bodhaine, B. A.; Dutton, E. G.; Harris, J. M.

    Aerosol data consisting of condensation nuclei (CN) counts, black carbon (BC) mass, aerosol light scattering (SC), and aerosol optical depth (AOD) measured at Barrow, Alaska from 1977 to 1994 have been analyzed by three-way positive matrix factorization (PMF3) by pooling all of the different data into one large three-way array. The PMF3 analysis identified four factors that indicate four different combinations of aerosol sources active throughout the year in Alaska. Two of the factors (F1, F2) represent Arctic haze. The first Arctic haze have factor F1 is dominant in January-February while the second factor F2 is dominant in March-April. They appear to be material that is generally ascribed to long-range transported anthropogenic particles. A lower ratio of condensation nuclei to scattering coefficient loadings is obtained for F2 indicating larger particles. Factor F3 is related to condensation nuclei. It has an annual cycle with two maxima, March and July-August indicating some involvement of marine biogenic sources. The fourth factor F4 represents the contribution to the stratospheric aerosol from the eruptions of El Chichon and Mt. Pinatubo. No significant long-term trend for F1 was detected while F2 shows a negative trend over the period from 1982 to 1994 but not over the whole measurement period. A positive trend of F3 over the whole period has been observed. This trend may be related to increased biogenic sulfur production caused by reductions in the sea-ice cover in the Arctic and/or an air temperature increase in the vicinity of Barrow. Potential source contribution function (PSCF) analysis showed that in winter and spring during 1989 to 1993 regions in Eurasia and North America are the sources of particles measured at barrow. In contrast to this, large areas in the North Pacific Ocean and the Arctic Ocean was contributed to observed high concentrations of CN in the summer season. Three-way positive matrix factorization was an effective method to extract

  11. Long-term aerosol measurements in Gran Canaria, Canary Islands: Particle concentration, sources and elemental composition

    Science.gov (United States)

    Gelado-Caballero, MaríA. D.; López-GarcíA, Patricia; Prieto, Sandra; Patey, Matthew D.; Collado, Cayetano; HéRnáNdez-Brito, José J.

    2012-02-01

    There are very few sets of long-term measurements of aerosol concentrations over the North Atlantic Ocean, yet such data is invaluable in quantifying atmospheric dust inputs to this ocean region. We present an 8-year record of total suspended particles (TSP) collected at three stations on Gran Canaria Island, Spain (Taliarte at sea level, Tafira 269 m above sea level (a.s.l.) and Pico de la Gorra 1930 m a.s.l.). Using wet and dry deposition measurements, the mean dust flux was calculated at 42.3 mg m-2 d-1. Air mass back trajectories (HYSPLIT, NOAA) suggested that the Sahara desert is the major source of African dust (dominant during 32-50% of days), while the Sahel desert was the major source only 2-10% of the time (maximum in summer). Elemental composition ratios of African samples indicate that, despite the homogeneity of the dust in collected samples, some signatures of the bedrocks can still be detected. Differences were found for the Sahel, Central Sahara and North of Sahara regions in Ti/Al, Mg/Al and Ca/Al ratios, respectively. Elements often associated with pollution (Pb, Cd, Ni, Zn) appeared to share a common origin, while Cu may have a predominantly local source, as suggested by a decrease in the enrichment factor (EF) of Cu during dust events. The inter-annual variability of dust concentrations is investigated in this work. During winter, African dust concentration measurements at the Pico de la Gorra station were found to correlate with the North Atlantic Oscillation (NAO) index.

  12. Economic development and traffic accident mortality in the industrialized world, 1962-1990

    NARCIS (Netherlands)

    E.F. van Beeck (Ed); G.J.J.M. Borsboom (Gerard); J.P. Mackenbach (Johan)

    2000-01-01

    textabstractBACKGROUND: We examined the association between prosperity and traffic accident mortality in the industrialized world in a long-term perspective. METHODS: We calculated traffic accident mortality, traffic mobility and the fatal injury rate of 21 industrializ

  13. Economic development and traffic accident mortality in the industrialized world, 1962-1990

    NARCIS (Netherlands)

    E.F. van Beeck (Ed); G.J.J.M. Borsboom (Gerard); J.P. Mackenbach (Johan)

    2000-01-01

    textabstractBACKGROUND: We examined the association between prosperity and traffic accident mortality in the industrialized world in a long-term perspective. METHODS: We calculated traffic accident mortality, traffic mobility and the fatal injury rate of 21

  14. Atmospheric moisture transports to the Arctic from different reanalyses: comparative assessment and analysis of source terms

    Science.gov (United States)

    Dufour, Ambroise; Zolina, Olga; Gulev, Sergey

    2014-05-01

    Accurate knowledge of the Arctic heat and moisture balances is critically important for understanding mechanisms of polar climate change and the observed amplification of the Arctic warming. Basic characteristics of the atmosphere in the Arctic region have quite a large spread in the modern era and first generation reanalyses, thus preventing effective use of reanalyses for the assessment of atmospheric moisture and heat transports and analysis of variability in the source terms. We used Eulerian approach to derive and intercompare to each other estimates of the moisture transports in the atmosphere from 5 reanalyses (ERA-Interim, MERRA, NCEP-CFSR, JRA-25, NCEP-1). Computational procedure involved decomposition of the velocity and moisture fields into mean conditions and variations around the mean. This concept allowed for the further association of the mean and eddy transports with large scale circulation modes (mean component) and synoptic transients (eddy component). The latter was associated with the characteristics of cyclone activity derived from the same reanalyses using state of the art numerical algorithm for cyclone identification and tracking. Atmospheric moisture transport is most intense over the GIN Sea and the North European basin, however over this area of the most intense transports, the contributions from the eddy and mean transport components are not correlated hinting on different pattern of variability in moisture fluxes due to cyclone activity and mean circulation. Decadal scale variability in the atmospheric moisture transports has been further associated with the Arctic-scale and regional differences between local precipitation and evaporation as well as with the magnitude of the storage terms. Potential mechanisms of variability in these terms are discussed.

  15. 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.

  16. Modelling and simulation the radioactive source-term of fission products in PWR type reactors; Modelagem e simulacao do termo-fonte radioativo de produtos de fissao em reatores nucleares do tipo PWR

    Energy Technology Data Exchange (ETDEWEB)

    Porfirio, Rogilson Nazare da Silva

    1996-07-01

    The source-term was defined with the purpose the quantify all radioactive nuclides released the nuclear reactor in the case of accidents. Nowadays the source-term is limited to the coolant of the primary circuit of reactors and may be measured or modelled with computer coders such as the TFP developed in this work. The calculational process is based on the linear chain techniques used in the CINDER-2 code. The TFP code considers forms of fission products release from the fuel pellet: Recoil, Knockout and Migration. The release from the gap to the coolant fluid is determined from the ratio between activity measured in the coolant and calculated activity in the gap. Considered the operational data of SURRY-1 reactor, the TFP code was run to obtain the source=term of this reactor. From the measured activities it was verified the reliability level of the model and the employed computational logic. The accuracy of the calculated quantities were compared to the measured data was considered satisfactory. (author)

  17. Variational Iterative Refinement Source Term Estimation Algorithm Assessment for Rural and Urban Environments

    Science.gov (United States)

    Delle Monache, L.; Rodriguez, L. M.; Meech, S.; Hahn, D.; Betancourt, T.; Steinhoff, D.

    2016-12-01

    It is necessary to accurately estimate the initial source characteristics in the event of an accidental or intentional release of a Chemical, Biological, Radiological, or Nuclear (CBRN) agent into the atmosphere. The accurate estimation of the source characteristics are important because many times they are unknown and the Atmospheric Transport and Dispersion (AT&D) models rely heavily on these estimates to create hazard assessments. To correctly assess the source characteristics in an operational environment where time is critical, the National Center for Atmospheric Research (NCAR) has developed a Source Term Estimation (STE) method, known as the Variational Iterative Refinement STE algorithm (VIRSA). VIRSA consists of a combination of modeling systems. These systems include an AT&D model, its corresponding STE model, a Hybrid Lagrangian-Eulerian Plume Model (H-LEPM), and its mathematical adjoint model. In an operational scenario where we have information regarding the infrastructure of a city, the AT&D model used is the Urban Dispersion Model (UDM) and when using this model in VIRSA we refer to the system as uVIRSA. In all other scenarios where we do not have the city infrastructure information readily available, the AT&D model used is the Second-order Closure Integrated PUFF model (SCIPUFF) and the system is referred to as sVIRSA. VIRSA was originally developed using SCIPUFF 2.4 for the Defense Threat Reduction Agency and integrated into the Hazard Prediction and Assessment Capability and Joint Program for Information Systems Joint Effects Model. The results discussed here are the verification and validation of the upgraded system with SCIPUFF 3.0 and the newly implemented UDM capability. To verify uVIRSA and sVIRSA, synthetic concentration observation scenarios were created in urban and rural environments and the results of this verification are shown. Finally, we validate the STE performance of uVIRSA using scenarios from the Joint Urban 2003 (JU03

  18. Cause Analysis of Wuhan Tianheng Building Pile Accident

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The geological condition and the original structure feature and foundation design of Wuhan Tianheng building are described. The accident appearance of pile foundation in the construction execution of work is illustrated. The generating source of this pile foundation accident is analyzed in great details.``

  19. Severe accident risks from external events

    Institute of Scientific and Technical Information of China (English)

    Randall O Gauntt

    2013-01-01

    This paper reviews the early development of design requirements for seismic events in USA early developing nuclear electric generating fleet.Notable safety studies,including WASH-1400,Sandia Siting Study and the NUREG-1150 probabilistic risk study,are briefly reviewed in terms of their relevance to extreme accidents arising from seismic and other severe accident initiators.Specific characteristic about the nature of severe accidents in nuclear power plant (NPP) are reviewed along with present day state-of-art analysis methodologies (methods for estimation of leakages and consequences of releases (MELCOR) and MELCOR accident consequence code system (MACCS)) that are used to evaluate severe accidents and to optimize mitigative and protective actions against such accidents.It is the aim of this paper to make nuclear operating nations aware of the risks that accompany a much needed energy resource and to identify some of the tools,techniques and landmark safety studies that serve to make the technology safer and to maintain vigilance and adequate safety culture for the responsible management of this valuable but unforgiving technology.

  20. Comprehensive analysis of atmospheric radionuclides just after the Fukushima accident

    Science.gov (United States)

    Tsuruta, Haruo; Oura, Yasuji; Ebihara, Mitsuru; Ohara, Toshimasa; Moriguchi, Yuichi; Nakajima, Teruyuki

    2017-04-01

    Even six years passed after the Fukushima Daiichi Nuclear Power Plant (FD1NPP) accident, we still have large uncertainty for atmospheric transport and deposition models, the estimate of release rate of source terms and of internal exposure from inhalation. For our better understanding and to reduce the uncertainty, we thoroughly analyzed all the published data of radionuclides such as Cs-137, I-131 and Xe-133, and of radiation dose rates at many monitoring sites in eastern Japan. We also retrieved the spatio-temporal distributions of Cs-137 just after the accident by using the unique dataset of hourly radionuclides in atmospheric aerosols collected on the used filter-tapes installed in the suspended particulate matter (SPM) monitors operated at more than 100 stations in the air pollution monitoring network of Japan. The most important findings are summarized as follows. Analyzing the hourly Cs-137 concentrations at two SPM stations located within 20 km from the FD1NPP, we revealed the complicated behavior of plumes and atmospheric radionuclides near the FD1NPP just after the accident. The transport pathways to the northwestern and northern areas from the FD1NPP are clarified especially on March 12-21, 2011. Analysis of the published data clearly shows that atmospheric ratio of I-131/Cs-137 (=R) was mainly divided into two groups, one (R≦10) is for the plumes before March 21, 2011, and the other (R>100) is after that day. These two groups are consistent in all the measured sites, whether the sites are in the Fukushima prefecture or in the Tokyo Metropolitan area. These results are expected partially to identify the source term for each plume.

  1. Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

    Science.gov (United States)

    Nooshiri, Nima; Saul, Joachim; Heimann, Sebastian; Tilmann, Frederik; Dahm, Torsten

    2017-02-01

    Global earthquake locations are often associated with very large systematic travel-time residuals even for clear arrivals, especially for regional and near-regional stations in subduction zones because of their strongly heterogeneous velocity structure. Travel-time corrections can drastically reduce travel-time residuals at regional stations and, in consequence, improve the relative location accuracy. We have extended the shrinking-box source-specific station terms technique to regional and teleseismic distances and adopted the algorithm for probabilistic, nonlinear, global-search location. We evaluated the potential of the method to compute precise relative hypocentre locations on a global scale. The method has been applied to two specific test regions using existing P- and pP-phase picks. The first data set consists of 3103 events along the Chilean margin and the second one comprises 1680 earthquakes in the Tonga-Fiji subduction zone. Pick data were obtained from the GEOFON earthquake bulletin, produced using data from all available, global station networks. A set of timing corrections varying as a function of source position was calculated for each seismic station. In this way, we could correct the systematic errors introduced into the locations by the inaccuracies in the assumed velocity structure without explicitly solving for a velocity model. Residual statistics show that the median absolute deviation of the travel-time residuals is reduced by 40-60 per cent at regional distances, where the velocity anomalies are strong. Moreover, the spread of the travel-time residuals decreased by ˜20 per cent at teleseismic distances (>28°). Furthermore, strong variations in initial residuals as a function of recording distance are smoothed out in the final residuals. The relocated catalogues exhibit less scattered locations in depth and sharper images of the seismicity associated with the subducting slabs. Comparison with a high-resolution local catalogue reveals that

  2. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...

  3. Boating 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...

  4. Accident resistant transport container

    Science.gov (United States)

    Andersen, John A.; Cole, James K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  5. 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.)

  6. Long-term dust aerosol production from natural sources in Iceland.

    Science.gov (United States)

    Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur

    2017-02-01

    Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland is volcanic sandy deserts. Not only do natural emissions from these sources influenced by strong winds affect regional air quality in Iceland ("Reykjavik haze"), but dust particles are transported over the Atlantic ocean and Arctic Ocean >1000 km at times. The aim of this paper is to place Icelandic dust production area into international perspective, present long-term frequency of dust storm events in northeast Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in northeast Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the northeastern erosion area, indicating extreme dust plume activity and erosion within the northeastern deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and Aeolian transport during dust/volcanic ash storms in Iceland, which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust may contribute to the Arctic air pollution.

  7. Long-term fluctuations of hailstorms in South Moravia, Czech Republic: synthesis of different data sources

    Science.gov (United States)

    Chromá, Kateřina; Brázdil, Rudolf; Dolák, Lukáš; Řezníčková, Ladislava; Valášek, Hubert; Zahradníček, Pavel

    2016-04-01

    Hailstorms belong to natural phenomena causing great material damage in present time, similarly as it was in the past. In Moravia (eastern part of the Czech Republic), systematic meteorological observations started generally in the latter half of the 19th century. Therefore, in order to create long-term series of hailstorms, it is necessary to search for other sources of information. Different types of documentary evidence are used in historical climatology, such as annals, chronicles, diaries, private letters, newspapers etc. Besides them, institutional documentary evidence of economic and administrative character (e.g. taxation records) has particular importance. This study aims to create a long-term series of hailstorms in South Moravia using various types of documentary evidence (such as taxation records, family archives, chronicles and newspapers which are the most important) and systematic meteorological observations in the station network. Although available hailstorm data cover the 1541-2014 period, incomplete documentary evidence allows reasonable analysis of fluctuations in hailstorm frequency only since the 1770s. The series compiled from documentary data and systematic meteorological observations is used to identify periods of lower and higher hailstorm frequency. Existing data may be used also for the study of spatial hailstorm variability. Basic uncertainties of compiled hailstorm series are discussed. Despite some bias in hailstorm data, South-Moravian hailstorm series significantly extends our knowledge about this phenomenon in the south-eastern part of the Czech Republic. The study is a part of the research project "Hydrometeorological extremes in Southern Moravia derived from documentary evidence" supported by the Grant Agency of the Czech Republic, reg. no. 13-19831S.

  8. Release modes and processes relevant to source-term calculations at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Apted, M.J. [Intera Information Technologies, Denver (United States)

    1994-12-31

    The feasibility of permanent disposal of radioactive high-level waste (HLW) in repositories located in deep geologic formations is being studied world-wide. The most credible release pathway is interaction between groundwater and nuclear waste forms, followed by migration of radionuclide-bearing groundwater to the accessible environment. Under hydrologically unsaturated conditions, vapor transport of volatile radionuclides is also possible. The near-field encompasses the waste packages composed of engineered barriers, while the far-field includes the natural barriers. Taken together, these two subsystems define a series of multiple, redundant barriers that act to assure the safe isolation of nuclear waste. In the U.S., the Department of energy (DOE) is investigating the feasibility of safe, long-term disposal of high-level nuclear waste at the Yucca Mountain site in Nevada. The proposed repository horizon is located in non-welded tuffs within the unsaturated zone (i.e. above the water table) at Yucca Mountain. The purpose of this paper is to describe the source-term models for radionuclide release from waste packages at Yucca Mountain site. The first section describes the conceptual release modes that are relevant for this site and waste package design, based on a consideration of the performance of currently proposed engineered barriers under expected and unexpected conditions. No attempt is made to asses the reasonableness nor probability of occurrence for any specific release mode. The following section reviews the waste-form characteristics that are required to model and constrain the release of radionuclides from the waste package. The next section present mathematical models for the conceptual release modes, selected from those that have been implemented into a probabilistic total system assessment code developed for the Electric Power Research Institute (EPRI). (author) 4 figs., 35 refs.

  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. Long-term change in the source contribution to surface ozone over Japan

    Science.gov (United States)

    Nagashima, Tatsuya; Sudo, Kengo; Akimoto, Hajime; Kurokawa, Junichi; Ohara, Toshimasa

    2017-07-01

    The relative contributions of various source regions to the long-term (1980-2005) increasing trend in surface ozone (O3) over Japan were estimated by a series of tracer-tagging simulations using a global chemical transport model. The model simulated the observed increasing trend in surface O3, including its seasonal variation and geographical features, in Japan well and demonstrated the relative roles of different source regions in forming this trend. Most of the increasing trend in surface O3 over Japan ( ˜ 97 %) that was simulated was explained as the sum of trends in contributions of different regions to photochemical O3 production. The increasing trend in O3 produced in China accounted for 36 % of the total increasing trend and those in the other northeast Asian regions (the Korean Peninsula, coastal regions in East Asia, and Japan) each accounted for about 12-15 %. Furthermore, the contributions of O3 created in the entire free troposphere and in western, southern, and southeastern Asian regions also increased, and their increasing trends accounted for 16 and 7 % of the total trend, respectively. The impact of interannual variations in climate, in methane concentration, and in emission of O3 precursors from different source regions on the relative contributions of O3 created in each region estimated above was also investigated. The variation of climate and the increase in methane concentration together caused the increase of photochemical O3 production in several regions, and represented about 19 % of the total increasing trend in surface O3 over Japan. The increase in emission of O3 precursors in China caused an increase of photochemical O3 production not only in China itself but also in the other northeast Asian regions and accounted for about 46 % of the total increase in surface O3 over Japan. Similarly, the relative impact of O3 precursor emission changes in the Korean Peninsula and Japan were estimated as about 16 and 4 % of the total increasing trend

  11. 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....

  12. Conception of transport cask with advanced safety, aimed at transportation and storage of spent nuclear fuel of power reactors, which meets the requirements of IAEA in terms of safety and increased stability during beyond-design-basis accidents and acts of terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Il' kaev, R.I.; Matveev, V.Z.; Morenko, A.I.; Shapovalov, V.I. [Russian Federal Nuclear Center - All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation); Semenov, A.G.; Sergeyev, V.M.; Orlov, V.K. [All-Russian Research Inst. of Inorganic Materials, Moscow (Russian Federation); Shatalov, V.V.; Gotovchikov, V.T.; Seredenko, V.A. [All-Russian Research Inst. of Applied Chemistry, Moscow (Russian Federation); Haire, Jonathan M.; Forsberg, C.W. [Oak Ridge National Lab., Oak Ridge (United States)

    2004-07-01

    The report is devoted to the problem of creation of a new generation of multi-purpose universal transport cask with advanced safety, aimed at transportation and storage of spent nuclear fuel (SNF) of power reactors, which meets all requirements of IAEA in terms of safety and increased stability during beyond-design-basis accidents and acts of terrorism. Meeting all IAEA requirements in terms of safety both in normal operation conditions and accidents, as well as increased stability of transport cask (TC) with SNF under the conditions of beyond-design-basis accidents and acts of terrorism has been achieved in the design of multi-purpose universal TC due to the use of DU (depleted uranium) in it. At that, it is suggested to use DU in TC, which acts as effective gamma shield and constructional material in the form of both metallic depleted uranium and metal-ceramic mixture (cermet), based on stainless or carbon steel and DU dioxide. The metal in the cermet is chosen to optimize cask performance. The use of DU in the design of multi-purpose universal TC enables getting maximum load of the container for spent nuclear fuel when meeting IAEA requirements in terms of safety and providing increased stability of the container with SNF under conditions of beyond-design-basis accident and acts of terrorism.

  13. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    Science.gov (United States)

    Yee, H. C.; Shinn, Judy L.

    1987-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogeneous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the source terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  14. On the application of ENO scheme with subcell resolution to conservation laws with stiff source terms

    Science.gov (United States)

    Chang, Shih-Hung

    1991-01-01

    Two approaches are used to extend the essentially non-oscillatory (ENO) schemes to treat conservation laws with stiff source terms. One approach is the application of the Strang time-splitting method. Here the basic ENO scheme and the Harten modification using subcell resolution (SR), ENO/SR scheme, are extended this way. The other approach is a direct method and a modification of the ENO/SR. Here the technique of ENO reconstruction with subcell resolution is used to locate the discontinuity within a cell and the time evolution is then accomplished by solving the differential equation along characteristics locally and advancing in the characteristic direction. This scheme is denoted ENO/SRCD (subcell resolution - characteristic direction). All the schemes are tested on the equation of LeVeque and Yee (NASA-TM-100075, 1988) modeling reacting flow problems. Numerical results show that these schemes handle this intriguing model problem very well, especially with ENO/SRCD which produces perfect resolution at the discontinuity.

  15. Long-term Performance of Moderate Heat Portland Cement with Double-expansive Sources

    Institute of Scientific and Technical Information of China (English)

    YE Qing; CHEN Huxing; KONG Deyu; WANG Shangxian; LOU Zonghan

    2007-01-01

    The long-term performance of moderate heat Portland cement with double-expansive sources (DE cement) in the system of high MgO clinker and gypsum was studied by XRD, SEM/EDAX and test methods for strength and expansion of cement. Results indicate that the periclase particle, whose size was 5-7.5 μm in DE cement clinker containing 4.8 % MgO, existed individually. The periclase hydration in hardened DE cement paste started at about 60 days and completed up to 2 000 days, and ettringite in the paste was stable from 3 days to 2 000 days. Under the conditions of 4.5%-5.0 % MgO in clinker and 2.8%-3.4 %SO3 in cement,ettringite expansion and brucite expansion in DE cement paste had a continuity, entirety and stability. At the ages of 90, 365, 730 and 2 000 days the expansion of the paste reached 0.07%-0.11%, 0.16%-0.21%, 0.21%-0.27% and 0.29%-0.38 %, respectively. The results suggest that by using this cement in mass concrete it may compensate its temperature shrinkage and autogenous shrinkage to some extent.

  16. Preliminary Evaluation on In-vessel Source Term based on 4S Methodology in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong Won; Chang, Won-Pyo; Seong, Seung Hwan; Ahn, Sang June; Kang, Seok Hun; Choi, Chi-Woong; Lee, Jin Yoo; Lee, Kwi Lim; Jeong, Jae-Ho; Jeong, Taekyeong; Ha, Kwi-Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This strategy requires nuclear plants to have features that prevent radionuclide release and multiple barriers to the escape from the plants of any radionuclides that are released despite preventive measures. Considerations of the ability to prevent and mitigate release of radionuclides arise at numerous places in the safety regulations of nuclear plants. The effectiveness of mitigative capabilities in nuclear plants is subject to quantitative analysis. The radionuclide input to these quantitative analyses of effectiveness is the Source Term (ST). All features of the composition, magnitude, timing, chemical form and physical form of accidental radionuclide release constitute the ST. Also, ST is defined as the release of radionuclides from the fuel and coolant into the containment, and subsequently to the environment. The many assumptions and equations evaluated in 4S are used. The in-vessel STs are calculated through several phases: The inventory of each radionuclide is calculated by ORIGEN-2 code using the peak burnup conditions. The nominal value of the radiological inventory is multiplied by a factor of 1.5 as an uncertainty margin to give the radiological inventory. ST in the release from the core to primary sodium is calculated by using the assumption of 4S methodology. Lastly, ST in the release from the primary sodium to cover gas space is calculated by using the assumption of 4S methodology.

  17. Heat Loss in a Laser-Driven, Magnetized, X-Ray Source with Thermoelectric Terms

    Science.gov (United States)

    Giuliani, J. L.; Velikovich, A. L.; Kemp, G. E.; Colvin, J. D.; Koning, J.; Fournier, K. B.

    2016-10-01

    The efficiency of laser-driven K-shell radiation sources, i.e., pipes containing a gas or a metal foam, may be improved by using an axial magnetic field to thermally insulate the pipe wall from the hot interior. A planar, self-similar solution for the magnetic and thermal diffusion is developed to model the near wall physics that includes the thermoelectric Nernst and Ettingshausen effects. This solution extends previous work for the MagLIF concept to include the full dependence of the transport coefficients on the electron Hall parameter. The analytic solution assumes a constant pressure. This case is matched with a 1D MHD code, which is then applied to the case allowing for pressure gradients. These numerical solutions are found to evolve toward the self-similar ones. The variation of the time integrated heat loss with and without the thermoelectric terms will be examined. The present work provides a verification test for general MHD codes that use Braginskii's or Epperlein-Haines' transport model to account for thermoelectric effects. NRL supported by the DOE/NNSA. LLNL work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  18. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Trial Calculation. Work Plan

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, Acacia J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The overall objective of the SFR Regulatory Technology Development Plan (RTDP) effort is to identify and address potential impediments to the SFR regulatory licensing process. In FY14, an analysis by Argonne identified the development of an SFR-specific MST methodology as an existing licensing gap with high regulatory importance and a potentially long lead-time to closure. This work was followed by an initial examination of the current state-of-knowledge regarding SFR source term development (ANLART-3), which reported several potential gaps. Among these were the potential inadequacies of current computational tools to properly model and assess the transport and retention of radionuclides during a metal fuel pool-type SFR core damage incident. The objective of the current work is to determine the adequacy of existing computational tools, and the associated knowledge database, for the calculation of an SFR MST. To accomplish this task, a trial MST calculation will be performed using available computational tools to establish their limitations with regard to relevant radionuclide release/retention/transport phenomena. The application of existing modeling tools will provide a definitive test to assess their suitability for an SFR MST calculation, while also identifying potential gaps in the current knowledge base and providing insight into open issues regarding regulatory criteria/requirements. The findings of this analysis will assist in determining future research and development needs.

  19. On the convergence rate of operator splitting for Hamilton-Jacobi equations with source terms

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, Espen R.; Karlsen, Kenneth H.; Risebro, Nils Henrik

    2000-02-01

    We establish a rate of convergence for a semi-discrete operator splitting method applied to Hamilton-Jacobi equations with source terms. The method is based on sequentially solving a Hamilton-Jacobi equation and an ordinary differential equation. The Hamilton-Jacobi equation is solved exactly while the ordinary differential equation is solved exactly or by an explicit Euler method. We prove that the L{sup {infinity}} error associated with the operator splitting method is bounded by O({delta}t), where {delta}t is the splitting (or time) step. This error bound is an improvement over the existing O((sqroot)({delta}t)) bound due to Souganidis [40]. In the one dimensional case, we present a fully discrete splitting method based on an unconditionally stable front tracking method for homogenuous Hamilton-Jacobi equations. It is proved that this fully discrete splitting method possesses a linear convergence rate. Moreover, numerical results are presented to illustrate the theoreticle convergence results. (author)

  20. Long-term effects of lead poisoning on bone mineralization in vultures exposed to ammunition sources

    Energy Technology Data Exchange (ETDEWEB)

    Gangoso, Laura [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: laurag@ebd.csic.es; Alvarez-Lloret, Pedro [Department of Mineralogy and Petrology, University of Granada, Avda Fuentenueva s/n, 18002 Granada (Spain)], E-mail: pedalv@ugr.es; Rodriguez-Navarro, Alejandro A.B. [Department of Mineralogy and Petrology, University of Granada, Avda Fuentenueva s/n, 18002 Granada (Spain)], E-mail: anava@ugr.es; Mateo, Rafael [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo s/n, 13071 Ciudad Real (Spain)], E-mail: Rafael.Mateo@uclm.es; Hiraldo, Fernando [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: hiraldo@ebd.csic.es; Donazar, Jose Antonio [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: donazar@ebd.csic.es

    2009-02-15

    Long-lived species are particularly susceptible to bioaccumulation of lead in bone tissues. In this paper we gain insights into the sublethal effects of lead contamination on Egyptian vultures (Neophron percnopterus). Our approach was done on the comparison of two populations (Canary Islands and Iberian Peninsula) differing in exposures to the ingestion of lead ammunition. Blood lead levels were higher in the island population (Canary Islands range: 5.10-1780 {mu}g L{sup -1}n = 137; Iberian Peninsula range: 5.60-217.30 {mu}g L{sup -1}n = 32) showing clear seasonal trends, peaking during the hunting season. Moreover, males were more susceptible to lead accumulation than females. Bone lead concentration increased with age, reflecting a bioaccumulation effect. The bone composition was significantly altered by this contaminant: the mineralization degree decreased as lead concentration levels increased. These results demonstrate the existence of long-term effects of lead poisoning, which may be of importance in the declines of threatened populations of long-lived species exposed to this contaminant. - Bone lead accumulation decreases the degree of bone mineralization in vultures exposed to ammunition sources.

  1. Cyclical Fluctuations in Workplace Accidents

    OpenAIRE

    Boone, J.; J. C. VAN OURS

    2002-01-01

    This Paper presents a theory and an empirical investigation on cyclical fluctuations in workplace accidents. The theory is based on the idea that reporting an accident dents the reputation of a worker and raises the probability that he is fired. Therefore a country with a high or an increasing unemployment rate has a low (reported) workplace accident rate. The empirical investigation concerns workplace accidents in OECD countries. The analysis confirms that workplace accident rates are invers...

  2. High-order scheme for the source-sink term in a one-dimensional water temperature model

    Science.gov (United States)

    Jing, Zheng; Kang, Ling

    2017-01-01

    The source-sink term in water temperature models represents the net heat absorbed or released by a water system. This term is very important because it accounts for solar radiation that can significantly affect water temperature, especially in lakes. However, existing numerical methods for discretizing the source-sink term are very simplistic, causing significant deviations between simulation results and measured data. To address this problem, we present a numerical method specific to the source-sink term. A vertical one-dimensional heat conduction equation was chosen to describe water temperature changes. A two-step operator-splitting method was adopted as the numerical solution. In the first step, using the undetermined coefficient method, a high-order scheme was adopted for discretizing the source-sink term. In the second step, the diffusion term was discretized using the Crank-Nicolson scheme. The effectiveness and capability of the numerical method was assessed by performing numerical tests. Then, the proposed numerical method was applied to a simulation of Guozheng Lake (located in central China). The modeling results were in an excellent agreement with measured data. PMID:28264005

  3. The Long-term Variability of the X-Ray Sources in NGC 6946 and NGC 4485/4490

    CERN Document Server

    Fridriksson, Joel K; Lewin, Walter H G; Kong, Albert K H; Pooley, David

    2008-01-01

    We analyze data from five Chandra observations of the spiral galaxy NGC 6946, and from three Chandra observations of the irregular/spiral interacting galaxy pair NGC 4485/4490, with an emphasis on investigating the long-term variability exhibited by the source populations. We detect 90 point sources coincident with NGC 6946 down to luminosities of a few times 10^36 erg/s, and 38 sources coincident with NGC 4485/90 down to a luminosity of ~1x10^37 erg/s. Twenty-five (fifteen) sources in NGC 6946 (NGC 4485/90) exhibit long-term (i.e., weeks to years) variability in luminosity; eleven (four) are transient candidates. The single ultraluminous X-ray source (ULX) in NGC 6946 and all but one of the eight ULXs in NGC 4485/90 exhibit long-term flux variability. Two of the ULXs in NGC 4485/90 have not been identified before as ultraluminous sources. The widespread variability in both systems is indicative of the populations being dominated by X-ray binaries, and this is supported by the X-ray colors of the sources. The...

  4. Fission product releases at severe LWR accident conditions: ORNL/CEA measurements versus calculations

    Energy Technology Data Exchange (ETDEWEB)

    Andre, B.; Ducros, G.; Leveque, J.P. [CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique; Osborne, M.F.; Lorenz, R.A. [Oak Ridge National Lab., TN (United States); Maro, D. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations

    1995-12-31

    Experimental programs in the United States and France have followed similar paths in supplying much of the data needed to analyze severe accidents. Both the HI/VI program, conducted at the Oak Ridge National Laboratory (ORNL) under the sponsorship of the U. S. Nuclear Regulatory Commission (NRC), and the HEVA/VERCORS program, supported by IPSN-Commissariat a l`Energie Atomique (CEA) and carried out at the Centre d`Etudes Nucleaires de Grenoble, have studied fission product release from light water reactor (LWR) fuel samples during test sequences representative of severe accidents. Recognizing that more accurate data, i.e., a better defined source term, could reduce the safety margins included in the rather conservative source terms originating from WASH-1400, the primary objective of these programs has been to improve the data base concerning fission product release and behavior at high temperatures. To facilitate the comparison, a model based on fission product diffusion mechanisms that was developed at ORNL and adapted with CEA experimental data is proposed. This CEA model is compared with the ORNL experimental data in a blind test. The two experimental programs used similar techniques in out-of-pile studies. Highly irradiated fuel samples were heated in radiofrequency induction furnaces to very high temperatures (up to 2700 K at ORNL and 2750 K at CEA) in oxidizing (H{sub 2}O), reducing (H{sub 2}) or mixed (H{sub 2}O+H{sub 2}) environments. The experimental parameters, which were chosen from calculated accident scenarios, did not duplicate specific accidents, but rather emphasized careful control of test conditions to facilitate extrapolation of the results to a wide variety of accident situations. This paper presents a broad and consistent database from ORNL and CEA release results obtained independently since the early 1980`S. A comparison of CORSOR and CORSOR Booth calculations, currently used in safety analysis, and the experimental results is presented and

  5. Study of safety features and accident scenarios in a fusion DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, M., E-mail: nakamura.makoto@jaea.go.jp [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Tobita, K. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Gulden, W. [Fusion for Energy, c/o EFDA Garching and Max-Plank-Institut fuer Plasmaphysik, Garching D-85748 (Germany); Watanabe, K. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Toshiba Corporation, Yokohama, Kanagawa 235-8523 (Japan); Someya, Y. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Tanigawa, H. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Sakamoto, Y. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Araki, T.; Matsumiya, H.; Ishii, K. [Toshiba Corporation, Yokohama, Kanagawa 235-8523 (Japan); Utoh, H. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Takase, H. [IFERC Project Team, Rokkasho, Aomori 039-3212 (Japan); Hayashi, T. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Satou, A.; Yonomoto, T. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Federici, G. [Fusion for Energy, c/o EFDA Garching and Max-Plank-Institut fuer Plasmaphysik, Garching D-85748 (Germany); Okano, K. [IFERC Project Team, Rokkasho, Aomori 039-3212 (Japan)

    2014-10-15

    Highlights: This paper reports progress in the fusion DEMO safety research conducted under the Broader Approach DEMO Design Activities; Hazards of a reference DEMO concept have been assessed; Reference accident event sequences in the reference DEMO in this study have been analyzed based on the master logic diagram (MLD) and the functional failure mode and effect analysis (FFMEA) techniques; Accident events of particular concern in the DEMO have been selected based on the MLD and FFMEA analysis. Abstract: After the Fukushima Dai-ichi nuclear accident, a need for assuring safety of fusion energy has grown in the Japanese (JA) fusion research community. DEMO safety research has been launched as a part of Broader Approach DEMO Design Activities (BA-DDA). This paper reports progress in the fusion DEMO safety research conducted under BA-DDA. Safety requirements and evaluation guidelines have been, first of all, established based on those established in the Japanese ITER site invitation activities. The radioactive source terms and energies that can mobilize such source terms have been assessed for a reference DEMO concept. This concept employs in-vessel components that are cooled by pressurized water and built of a low activation ferritic steel (F82H), contains solid pebble beds made of lithium-titanate (Li{sub 2}TiO{sub 3}) and beryllium–titanium (Be{sub 12}Ti) for tritium breeding and neutron multiplication, respectively. It is shown that unlike the energies expected in ITER, the enthalpy in the first wall/blanket cooling loops is large compared to the other energies expected in the reference DEMO concept. Reference accident event sequences in the reference DEMO in this study have been analyzed based on the Master Logic Diagram and Functional Failure Mode and Effect Analysis techniques. Accident events of particular concern in the DEMO have been selected based on the event sequence analysis and the hazard assessment.

  6. 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.

  7. 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).

  8. Inhalation Dose and Source Term Studies in a Tribal Area of Wayanad, Kerala, India

    Directory of Open Access Journals (Sweden)

    Reshma Bhaskaran

    2017-01-01

    Full Text Available Among radiation exposure pathways to human beings, inhalation dose is the most prominent one. Radon, thoron, and their progeny contribute more than 50 per cent to the annual effective dose due to natural radioactivity. South west coast of India is classified as a High Natural Background Radioactivity Area and large scale data on natural radioactivity and dosimetry are available from these coastal regions including the Neendakara-Chavara belt in the south of Kerala. However, similar studies and reports from the northern part of Kerala are scarce. The present study involves the data collection and analysis of radon, thoron, and progeny concentration in the Wayanad district of Kerala. The radon concentration was found to be within a range of 12–378 Bq/m3. The thoron concentration varied from 15 to 621 Bq/m3. Progeny concentration of radon and thoron and the diurnal variation of radon were also studied. In order to assess source term, wall and floor exhalation studies have been done for the houses showing elevated concentration of radon and thoron. The average values of radon, thoron, and their progeny are found to be above the Indian average as well as the average values reported from the High Natural Background Radioactivity Areas of Kerala. Exhalation studies of the soil samples collected from the vicinity of the houses show that radon mass exhalation rate varied from below detectable limit (BDL to a maximum of 80 mBq/kg/h. The thoron surface exhalation rate ranged from BDL to 17470 Bq/m2/h.

  9. Iodine behaviour in severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, L.M.C.; Grindon, E.; Handy, B.J.; Sutherland, L. [NNC Ltd., Knutsford (United Kingdom); Bruns, W.G.; Sims, H.E. [AEA Technology, Harwell (United Kingdom); Dickinson, S. [AEA Technology, Winfrith (United Kingdom); Hueber, C.; Jacquemain, D. [IPSN/CEA, Cadarache, Saint Paul-Lez-Durance (France)

    1996-12-01

    A description is given of analyses which identify which aspects of the modelling and data are most important in evaluating the release of radioactive iodine to the environment following a potential severe accident at a PWR and which identify the major uncertainties which affect that release. Three iodine codes are used namely INSPECT, IODE and IMPAIR, and their predictions are compared with those of the PSA code MAAP. INSPECT is a mechanistic code which models iodine behaviour in the aqueous aerosol, spray water and sump water, and the partitioning of volatile species between the aqueous phases and containment gas space. Organic iodine is not modelled. IODE and IMPAIR are semi-empirical codes which do not model iodine behaviour in the aqueous aerosol, but model organic iodine. The fault sequences addressed are based on analyses for the Sizewell `B` design. Two types of sequence have been analysed.: (a) those in which a major release of fission products from the primary circuit to the containment occur, e.g. a large LOCAS, (b) those where the release by-passes the containment, e.g. a leak into the auxiliary building. In the analysis of the LOCA sequences where the pH of the sump is controlled to be a value of 8 or greater, all three codes predict that the oxidation of iodine to produce gas phase species does not make a significant contribution to the source term due to leakage from the reactor building and that the latter is dominated by iodide in the aerosol. In the case where the pH of the sump is not controlled, it is found that the proportion of gas phase iodine increases significantly, although the cumulative leakage predicted by all three codes is not significantly different from that predicted by MAAP. The radiolytic production of nitric acid could be a major factor in determining the pH, and if the pH were reduced, the codes predict an increase in gas phase iodine species leaked from the containment. (author) 4 figs., 7 tabs., 13 refs.

  10. Severe Accident Recriticality Analyses (SARA)

    Energy Technology Data Exchange (ETDEWEB)

    Frid, W. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Hoejerup, F. [Risoe National Lab. (Denmark); Lindholm, I.; Miettinen, J.; Puska, E.K. [VTT Energy, Helsinki (Finland); Nilsson, Lars [Studsvik Eco and Safety AB, Nykoeping (Sweden); Sjoevall, H. [Teoliisuuden Voima Oy (Finland)

    1999-11-01

    rate of 2000 kg/s. In most cases, however, the predicted energy deposition was much smaller, below the regulatory limits for fuel failure, but close or above recently observed thresholds for fragmentation and dispersion of high burn-up fuel. The highest calculated quasi steady-state power following initial power excursion was in most cases about 20 % of the nominal reactor power, according to SIMULATE-3K and APROS. RECRIT predictions were in general different in this respect with either oscillating power or power increase approaching 50 % of nominal power which in both cases resulted in fuel temperatures above the melting point as a result of insufficient cooling. Long-term containment response to recriticality was assessed through MELCOR calculations for Olkiluoto 1 plant. At stabilised reactor power of 19 % of nominal power the containment failure due to overpressurization was predicted to occur 1.3 h after recriticality, if the accident is not mitigated. The SARA studies have clearly shown the sensitivity of recriticality phenomena to thermal-hydraulic modelling, the specifics of accident scenario, such as distribution of boron-carbide, and importance of multi-dimensional kinetics for determination of local power distribution in the core. The results of the project have pointed out the importance of adequate accident management procedures to be used by reactor operators and emergency staff during recovery actions. Recommendations in this area are given in the report.

  11. Major Differences in Rates of Occupational Accidents between Different nationalities of Seafarers

    DEFF Research Database (Denmark)

    Hansen, Henrik L.; Laursen, Lise Hedegaard; Frydberg, Morten;

    2008-01-01

    sources on occurrence of accidents were used and to identify specific causes of excess accident rates among certain nationalities. METHODS: Occupational accidents aboard Danish merchant ships during one year were identified from four different sources. These included accidents reported to the maritime....... Differences in approach to safety and risk taking between South East Asian and European seafarers should be identified and positives attitudes included in accident preventing programmes. Main messages Seafarers from South East Asia, mainly the Philippines, seem to have a genuine lower risk of occupational...

  12. Who by accident? The social morphology of car accidents.

    Science.gov (United States)

    Factor, Roni; Yair, Gad; Mahalel, David

    2010-09-01

    Prior studies in the sociology of accidents have shown that different social groups have different rates of accident involvement. This study extends those studies by implementing Bourdieu's relational perspective of social space to systematically explore the homology between drivers' social characteristics and their involvement in specific types of motor vehicle accident. Using a large database that merges official Israeli road-accident records with socioeconomic data from two censuses, this research maps the social order of road accidents through multiple correspondence analysis. Extending prior studies, the results show that different social groups indeed tend to be involved in motor vehicle accidents of different types and severity. For example, we find that drivers from low socioeconomic backgrounds are overinvolved in severe accidents with fatal outcomes. The new findings reported here shed light on the social regularity of road accidents and expose new facets in the social organization of death. © 2010 Society for Risk Analysis.

  13. Assessment of CRBR core disruptive accident energetics

    Energy Technology Data Exchange (ETDEWEB)

    Theofanous, T.G.; Bell, C.R.

    1984-03-01

    The results of an independent assessment of core disruptive accident energetics for the Clinch River Breeder Reactor are presented in this document. This assessment was performed for the Nuclear Regulatory Commission under the direction of the CRBR Program Office within the Office of Nuclear Reactor Regulation. It considered in detail the accident behavior for three accident initiators that are representative of three different classes of events; unprotected loss of flow, unprotected reactivity insertion, and protected loss of heat sink. The primary system's energetics accommodation capability was realistically, yet conservatively, determined in terms of core events. This accommodation capability was found to be equivalent to an isentropic work potential for expansion to one atmosphere of 2550 MJ or a ramp rate of about 200 $/s applied to a classical two-phase disassembly.

  14. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source Reactor at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

    1995-09-01

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effects of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

  15. ALICE Injected Beam Accidents

    CERN Document Server

    Appleby, R B

    2009-01-01

    The ALICE (point 2) interaction region is sensitive to beam orbit errors arising from magnet setting errors on injection. In this report, beam accident scenarios under injection for ALICE are described, focusing on ultra- fast error injection scenarios for the interaction straight correctors and dipoles. Beam 1 and beam 2 accident scenarios are considered, where the errors can lead to beam orbits striking the ALICE vacuum chamber or elements of the machine. The required thresholds for magnet current interlocks are calculated to avoid machine and detector risk.

  16. LHCb Injected Beam Accidents

    CERN Document Server

    Appleby, R B

    2009-01-01

    The LHCb (point 8) interaction region is sensitive to beam orbit errors arising from magnet setting errors on injection. In this report, beam accident scenarios under injection for LHCb are described, focusing on ultra- fast error injection scenarios for the interaction straight correctors and dipoles. Beam 1 and beam 2 accident scenarios are considered, where the errors can lead to beam orbits striking the LHCb vacuum chamber or elements of the machine. The required thresholds for magnet current interlocks are calculated to avoid machine and detector risk.

  17. Nonradioactive Environmental Emissions Chemical Source Term for the Double Shell Tank (DST) Vapor Space During Waste Retrieval Operations

    Energy Technology Data Exchange (ETDEWEB)

    MAY, T.H.

    2000-04-21

    A nonradioactive chemical vapor space source term for tanks on the Phase 1 and the extended Phase 1 delivery, storage, and disposal mission was determined. Operations modeled included mixer pump operation and DST waste transfers. Concentrations of ammonia, specific volatile organic compounds, and quantitative volumes of aerosols were estimated.

  18. Determination of a source term for a time fractional diffusion equation with an integral type over-determining condition

    Directory of Open Access Journals (Sweden)

    Timurkhan S. Aleroev

    2013-12-01

    Full Text Available We consider a linear heat equation involving a fractional derivative in time, with a nonlocal boundary condition. We determine a source term independent of the space variable, and the temperature distribution for a problem with an over-determining condition of integral type. We prove the existence and uniqueness of the solution, and its continuous dependence on the data.

  19. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources

    Directory of Open Access Journals (Sweden)

    Vandana S

    2010-01-01

    Full Text Available Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR -1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR of a reference 137 Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference 137 Cs brachytherapy source (CDCSJ5, and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA, Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference 137 Cs source. All required correction factors were applied in the calculation of the RAKR of the 137 Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within ±0.5% for about three years after calibration/recalibration. However, it shows deviations larger than ±0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  20. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources.

    Science.gov (United States)

    Vandana, S; Sharma, S D

    2010-04-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference (137)Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference (137)Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference (137)Cs source. All required correction factors were applied in the calculation of the RAKR of the (137)Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within +/-0.5% for about three years after calibration/recalibration. However, it shows deviations larger than +/-0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  1. TMI-2 Reactor Building source term measurements: surfaces and basement water and sediment

    Energy Technology Data Exchange (ETDEWEB)

    McIsaac, C V; Keefer, D G

    1984-10-01

    Presented in this report are the results of radiochemical and elemental analyses performed on samples collected from the Three Mile Island Unit 2 Reactor Building from August 1979 to December 1983. The quantities of fission products and core materials that were measured on the external surfaces in the Reactor Building or in the water and sediment in its basement are summarized. Recent analysis results for access panels removed from the air cooling assembly and for liquid and particulate samples collected from the Reactor Building sump and reactor coolant drain tank are included in the report. Measurements show that 59% of the /sup 3/H, 2.7% of the /sup 90/Sr, 15% of the /sup 129/I, 20% of the /sup 131/I, and 42% of the /sup 137/Cs originally in the core at the time of the accident could be accounted for outside the core in the Reactor Building. With the exceptions of /sup 90/Sr and /sup 144/Ce, the vast majority of each radionuclide released was found dispersed in the water and sediment in the basement.

  2. Corrosion of Uranium in Desert Soil, with Application to GCD Source Term M

    Energy Technology Data Exchange (ETDEWEB)

    ANDERSON, HOWARD L.; BACA, JULIANNE; KRUMHANSL, JAMES L.; STOCKMAN, HARLAN W.; THOMPSON, MOLLIE E.

    1999-09-01

    Uranium fragments from the Sandia Sled Track were studied as analogues for weapons components and depleted uranium buried at the Greater Confinement Disposal (GCD) site in Nevada. The Sled Track uranium fragments originated as weapons mockups and counterweights impacted on concrete and soil barriers, and experienced heating and fragmentation similar to processes thought to affect the Nuclear Weapons Accident Residues (NWAR) at GCD. Furthermore, the Sandia uranium was buried in unsaturated desert soils for 10 to 40 years, and has undergone weathering processes expected to affect the GCD wastes. Scanning electron microscopy, X-ray diffraction and microprobe analyses of the fragments show rapid alteration from metals to dominantly VI-valent oxy-hydroxides. Leaching studies of the samples give results consistent with published U-oxide dissolution rates, and suggest longer experimental periods (ca. 1 year) would be required to reach equilibrium solution concentrations. Thermochemical modeling with the EQ3/6 code indicates that the uranium concentrations in solutions saturated with becquerelite could increase as the pore waters evaporate, due to changes in carbonate equilibria and increased ionic strength.

  3. Recent severe accident research synthesis of the major outcomes from the SARNET network

    Energy Technology Data Exchange (ETDEWEB)

    Van Dorsselaere, J.-P., E-mail: jean-pierre.van-dorsselaere@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Saint-Paul-lez-Durance (France); Auvinen, A. [VTT Technical Research Centre, Espoo (Finland); Beraha, D. [Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), Köln (Germany); Chatelard, P. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Saint-Paul-lez-Durance (France); Herranz, L.E. [Centro de Investigaciones Energéticas MedioAmbientales y Tecnológicas (CIEMAT), Madrid (Spain); Journeau, C. [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Paris (France); Klein-Hessling, W. [Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), Köln (Germany); Kljenak, I. [Jozef Stefan Institute (JSI), Ljubljana (Slovenia); Miassoedov, A. [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Paci, S. [University of Pisa, Pisa (Italy); Zeyen, R. [European Commission Joint Research Centre, Institute for Energy (JRC/IET), Petten (Netherlands)

    2015-09-15

    Highlights: • SARNET network of excellence integration mid-2013 in the NUGENIA Association. • Progress of knowledge on corium behaviour, hydrogen explosion and source term. • Further development of ASTEC integral code to capitalize knowledge. • Ranking of next R&D high priority issues accounting for international research. • Dissemination of knowledge through education courses and ERMSAR conferences. - Abstract: The SARNET network (Severe Accident Research NETwork of excellence), co-funded by the European Commission from 2004 to 2013, has allowed to significantly improve the knowledge on severe accidents and to disseminate it through courses and ERMSAR conferences. The major investigated topics, involving more than 250 researchers from 22 countries, were in- and ex-vessel corium/debris coolability, molten-core–concrete-interaction, steam explosion, hydrogen combustion and mitigation in containment, impact of oxidising conditions on source term, and iodine chemistry. The ranking of the high priority issues was updated to account for the results of recent international research and for the impact of Fukushima nuclear accidents in Japan. In addition, the ASTEC integral code was further developed to capitalize the new knowledge. The network has reached self-sustainability by integration in mid-2013 into the NUGENIA Association. The main activities and outcomes of the network are presented.

  4. On-line measurement of gaseous iodine species during a PWR severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Haykal, I.; Doizi, D. [CEA, DEN, Departement de Physico-chimie, 91191 Gif sur Yvette Cedex, (France); Perrin, A. [CNRS-University of Paris Est and Paris 7, Laboratoire Inter-Universitaire des Systemes Atmospheriques, 94010 Creteil, (France); Vincent, B. [University of Burgundy, Laboratoire de physique, CNRS UMR 5027, 9, Avenue Alain Savary, BP 47870, F-21078 Dijon Cedex, (France); Manceron, L. [Synchrotron SOLEIL, L' Orme des Merisiers, St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, (France); Mejean, G. [University of Joseph Fourier in Grenoble, Laboratoire de Spectrometrie Physique-CNRS UMR 5588, 38402 Saint Martin d' Heres, (France); Ducros, G. [CEA Cadarache, CEA, DEN, Departement d' Etudes des Combustibles, 13108 Saint-Paul-lez-Durance cedex, (France)

    2015-07-01

    A long-range remote sensing of severe accidents in nuclear power plants can be obtained by monitoring the online emission of volatile fission products such as xenon, krypton, caesium and iodine. The nuclear accident in Fukushima was ranked at level 7 of the International Nuclear Event Scale by the NISA (Nuclear and Industrial Safety Agency) according to the importance of the radionuclide release and the off-site impact. Among volatile fission products, iodine species are of high concern, since they can be released under aerosols as well as gaseous forms. Four years after the Fukushima accident, the aerosol/gaseous partition is still not clear. Since the iodine gaseous forms are less efficiently trapped by the Filtered Containment Venting Systems than aerosol forms, it is of crucial importance to monitor them on-line during a nuclear accident, in order to improve the source term assessment in such a situation. Therefore, we propose to detect and quantify these iodine gaseous forms by the use of highly sensitive optical methods. (authors)

  5. Assessment of the potential impact of Nuclear Power Plant accidents on aviation

    Science.gov (United States)

    Wotawa, Gerhard; Arnold, Delia; Maurer, Christian

    2014-05-01

    The nuclear accidents in Chernobyl in 1986 and in Fukushima in 2011 demonstrated the urgent need to provide adequate guidance for land-based, marine and airborne transport. Quick assessments of potential impacts are essential to avoid unnecessary traffic disruptions while guaranteeing appropriate safety levels for staff in the transport industry as well as travellers. Such estimates are to be provided under difficult circumstances, mostly due to the lack of reliable initial information on the severity of the accident and the exact source term of radionuclides. Regarding aviation, there are three equally relevant aspects to look at, namely aircraft in cruising altitude (about 40000 ft), aircraft approaching an airport, and finally the airports as such as critical infrastructure, including airport operations and ground transport. Based on the accident scenarios encountered in the Chernobyl and Fukushima cases, exemplary case studies shall be provided to assess the potential impacts of such events on aviation. The study is based on the Atmospheric Transport and Dispersion Model (ATDM) FLEXPART and a simplified scheme to calculate effective dose rates based on a few key radionuclides (Cs-137, I-131 and Xe-133). Besides the impact assessment, possible new products provided by WMO Regional Specialized Meteorological Centres in the event of an accident shall be discussed as well.

  6. Current research and development activities on fission products and hydrogen risk after the accident at Fukushima Daiichi nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Takeshi; Hoshi, Harutaka; Hotta, Akitoshi [Regulatory Standard and Research Department, Secretariat of Nuclear Regulation Authority, Tokyo (Japan)

    2015-02-15

    After the Fukushima Daiichi nuclear power plant (NPP) accident, new regulatory requirements were enforced in July 2013 and a backfit was required for all existing nuclear power plants. It is required to take measures to prevent severe accidents and mitigate their radiological consequences. The Regulatory Standard and Research Department, Secretariat of Nuclear Regulation Authority (S/NRA/R) has been conducting numerical studies and experimental studies on relevant severe accident phenomena and countermeasures. This article highlights fission product (FP) release and hydrogen risk as two major areas. Relevant activities in the S/NRA/R are briefly introduced, as follows: 1. For FP release: Identifying the source terms and leak mechanisms is a key issue from the viewpoint of understanding the progression of accident phenomena and planning effective countermeasures that take into account vulnerabilities of containment under severe accident conditions. To resolve these issues, the activities focus on wet well venting, pool scrubbing, iodine chemistry (in-vessel and ex-vessel), containment failure mode, and treatment of radioactive liquid effluent. 2. For hydrogen risk: because of three incidents of hydrogen explosion in reactor buildings, a comprehensive reinforcement of the hydrogen risk management has been a high priority topic. Therefore, the activities in evaluation methods focus on hydrogen generation, hydrogen distribution, and hydrogen combustion.

  7. Authority structure and industrial accidents

    NARCIS (Netherlands)

    As, Sicco van

    2001-01-01

    This paper deals with the influence of organizational characteristics on safety. Accidents are actually caused by individual mistakes. However the underlying causes of accidents are often organizational. The general hypothesis is that the authority structure is a main cause of accident-proneness

  8. private placements as sources of long term funds for publicly quoted ...

    African Journals Online (AJOL)

    USER

    Nigerian capital market by publicly quoted companies. These practices previously .... (proportion of profit that is not spent). External sources of ... security does not benefit from access to the Stock Exchange trading market. Also they tend to be ...

  9. Economic development, mobility and traffic accidents in Algeria.

    Science.gov (United States)

    Bougueroua, M; Carnis, L

    2016-07-01

    The aim of this contribution is to estimate the impact of road economic conditions and mobility on traffic accidents for the case of Algeria. Using the cointegration approach and vector error correction model (VECM), we will examine simultaneously short term and long-term impacts between the number of traffic accidents, fuel consumption and gross domestic product (GDP) per capital, over the period 1970-2013. The main results of the estimation show that the number of traffic accidents in Algeria is positively influenced by the GDP per capita in the short and long term. It implies that a higher economic development worsens the road safety situation. However, the new traffic rules adopted in 2009 have an impact on the forecast trend of traffic accidents, meaning efficient public policy could improve the situation. This result calls for a strong political commitment with effective countermeasures for avoiding the further deterioration of road safety record in Algeria.

  10. Experimental investigations relevant for hydrogen and fission product issues raised by the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sanjeev [Becker Technologies GmbH, Eschborn (Germany)

    2015-02-15

    The accident at Japan's Fukushima Daiichi nuclear power plant in March 2011, caused by an earthquake and a subsequent tsunami, resulted in a failure of the power systems that are needed to cool the reactors at the plant. The accident progression in the absence of heat removal systems caused Units 1-3 to undergo fuel melting. Containment pressurization and hydrogen explosions ultimately resulted in the escape of radioactivity from reactor containments into the atmosphere and ocean. Problems in containment venting operation, leakage from primary containment boundary to the reactor building, improper functioning of standby gas treatment system (SGTS), unmitigated hydrogen accumulation in the reactor building were identified as some of the reasons those added-up in the severity of the accident. The Fukushima accident not only initiated worldwide demand for installation of adequate control and mitigation measures to minimize the potential source term to the environment but also advocated assessment of the existing mitigation systems performance behavior under a wide range of postulated accident scenarios. The uncertainty in estimating the released fraction of the radionuclides due to the Fukushima accident also underlined the need for comprehensive understanding of fission product behavior as a function of the thermal hydraulic conditions and the type of gaseous, aqueous, and solid materials available for interaction, e.g., gas components, decontamination paint, aerosols, and water pools. In the light of the Fukushima accident, additional experimental needs identified for hydrogen and fission product issues need to be investigated in an integrated and optimized way. Additionally, as more and more passive safety systems, such as passive autocatalytic recombiners and filtered containment venting systems are being retrofitted in current reactors and also planned for future reactors, identified hydrogen and fission product issues will need to be coupled with the

  11. Recovery of wild Pacific oyster, Crassostrea gigas in terms of reproduction and gametogenesis two-years after the Hebei Spirit Oil Spill Accident off the West Coast of Korea

    Science.gov (United States)

    Mondol, Mostafizur Rahman; Keshavmurthy, Shashank; Lee, Hee-Jung; Hong, Hyun-Ki; Park, Heung-Sik; Park, Sang-Rul; Kang, Chang-Keun; Choi, Kwang-Sik

    2015-12-01

    The Hebei Spirit oil spill in December 2007 at Taean off the west coast of Korea was the largest oil tanker accident in Korea. However, the impact of the spill on physiology of benthic animals remains largely unknown. Two-years after the accident, we compared reproductive effort and annual gametogenesis of the wild Pacific oyster Crassostrea gigas, residing at oil spill site with a control oyster population in Incheon Bay, North-West coast of Korea. Results showed that the oyster sampled from the oil spill site showed a significantly higher (279.0 mg standard animal-1, Panimal-1, Panimal-1, Panimal-1, Panimal-1, Panimal-1, Pphysiological status to normal level after two years of the oil spill accident.

  12. Major Differences in Rates of Occupational Accidents between Different nationalities of Seafarers

    DEFF Research Database (Denmark)

    Hansen, Henrik L.; Laursen, Lise Hedegaard; Frydberg, Morten

    2008-01-01

    OBJECTIVES: Earlier studies and statistics have shown that merchant seafarers from the South East Asia had considerable lower accident rates when compared with seafarers from Western Europe. The purposes of the study were to investigate whether the earlier observations were sustained if further...... sources on occurrence of accidents were used and to identify specific causes of excess accident rates among certain nationalities. METHODS: Occupational accidents aboard Danish merchant ships during one year were identified from four different sources. These included accidents reported to the maritime...... authorities, accidents reported to a mutual insurance company, files on medical costs reimbursed by the government and finally, accidents in which there has been contact to the radio medical service. Time at risk aboard was obtained from a register on all employment periods aboard merchant ships. RESULTS...

  13. Long term variability of radio sources in the frequencies of 22 GHz and 44 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Botti, L.C.L.; Abraham, Z.

    1987-05-01

    The radio sources 3C273, OV236, Cen A and Sgr A were observed during a period of six years (1980-1986), in the frequencies of 22 GHz and 44 GHz, with the Itapetinga radiotelescope (Brazil). The objective of this work was the detection of variability in the intensity and in the shape of the spectra of the sources. All of them presented some variability, specially the quasar 3C273, which after a period of intense activity (1981-1985), returned to its quiescent level at the end of 1985. The increase of the flux density in these frequencies is associated to the ejection of new components by the central source in the quasar, as observed in the maps obtained by VLBI techniques. 17 references, 4 figures.

  14. In-stream attenuation of nitrogen and phosphorus from major point source in large-scale watershed: mixed source and long-term variation

    Science.gov (United States)

    Chen, X.; Fulda, M.; Keller, A. A.

    2011-12-01

    Increased human activity in agriculture and industry has posed significant impact on natural water bodies and resulted in water quality deterioration. Agricultural non-point source pollution and urban point source discharge from municipal waste water treatment plant are the more recent concerns. Computer models are often used to help assess the fate and transport of pollutant, which involves complex interactions such as adsorption, biochemical reaction and plants uptake. However, it remains to be a challenge to assess the attenuation of total nitrogen and total phosphorus in large-scale watershed where there are significant difference in land use types and soil properties, especially when there are significant temporal variations through a long-term simulation. In this study, a large-scale watershed model in the Ohio River Basin was constructed considering a ten year simulation period. To assess the downstream impacts of increasing or decreasing nutrient loads, a hypothetical waste water treatment plant was added as the point source in different subwatersheds, monitoring the downstream effects. Five scenarios (100 kg/d Ammonia, 100 kg/d Nitrate, 100 kg/d Phosphate, mixed 100 kg/d Ammonia & 100 kg/d Phosphate and mixed 100 kg/d Nitrate & 100 kg/d Phosphate) were examined to assess the attenuation process throughout the 10-years simulation. In addition to significant differences in the attenuation in different subwatersheds, the various loads had complex interrelations. We also observed significant variations in attenuation for short-term simulation, while in long-term, the attenuation factors tended to be stabilized.

  15. Occupational accidents aboard merchant ships

    DEFF Research Database (Denmark)

    Hansen, H.L.; Nielsen, D.; Frydenberg, Morten

    2002-01-01

    Objectives: To investigate the frequency, circumstances, and causes of occupational accidents aboard merchant ships in international trade, and to identify risk factors for the occurrence of occupational accidents as well as dangerous working situations where possible preventive measures may...... be initiated. Methods: The study is a historical follow up on occupational accidents among crew aboard Danish merchant ships in the period 1993–7. Data were extracted from the Danish Maritime Authority and insurance data. Exact data on time at risk were available. Results: A total of 1993 accidents were...... rate of accidents than Danish citizens. Age was a major risk factor for accidents causing permanent disability. Change of ship and the first period aboard a particular ship were identified as risk factors. Walking from one place to another aboard the ship caused serious accidents. The most serious...

  16. Increase the Safety of Road Traffic Accidents by Applying Clustering

    Directory of Open Access Journals (Sweden)

    Kos Goran

    2013-12-01

    Full Text Available In terms of continual increase of number of traffic accidents and alarming trend of increasing number of traffic accidents with catastrophic consequences for human life and health, it is necessary to actively research and develop methods to combat these trends. One of the measures is the implementation of advanced information systems in existing traffic environment. Accidents clusters, as databases of traffic accidents, introduce a new dimension in traffic systems in the form of experience, providing information on current accidents and the ones that have previously occurred in a given period. This paper proposes a new approach to predictive management of traffic processes, based on the collection of data in real time and is based on accidents clusters. The modern traffic information services collects road traffic status data from a wide variety of traffic sensing systems using modern ICT technologies, creating the most accurate road traffic situation awareness achieved so far. Road traffic situation awareness enhanced by accident clusters' data can be visualized and distributed in various ways (including the forms of dynamic heat maps and on various information platforms, suiting the requirements of the end-users. Accent is placed on their significant features that are based on additional knowledge about existing traffic processes and distribution of important traffic information in order to prevent and reduce traffic accidents.

  17. 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.

  18. Accident Management & Risk-Based Compliance With 40 CFR 68 for Chemical Process Facilities

    Energy Technology Data Exchange (ETDEWEB)

    O`Kula, K.R. [Westinghouse Savannah River Company, AIKEN, SC (United States); Taylor, R.P. Jr.; Ashbaugh, S.G. [Innovative Technology Solutions, Albuquerque, NM (United States)

    1995-08-23

    A risk-based logic model is suggested as an appropriate basis for better predicting accident progression and ensuing source terms to the environment from process upset conditions in complex chemical process facilities. Under emergency conditions, decision-makers may use the Accident Progression Event Tree approach to identify the best countermeasure for minimizing deleterious consequences to receptor groups before the atmospheric release has initiated. It is concluded that the chemical process industry may use this methodology as a supplemental information provider to better comply with the Environmental Protection Agency`s proposed 40 CFR 68 Risk Management Program rule. An illustration using a benzene-nitric acid potential interaction demonstrates the value of the logic process. The identification of worst-case releases and planning for emergency response are improved through these methods, at minimum. It also provides a systematic basis for prioritizing facility modifications to correct vulnerabilities.

  19. Evaluation of the Transient Hydrologic Source Term for the Cambric Underground Nuclear Test at Frenchman Flat, Nevada test Site

    Energy Technology Data Exchange (ETDEWEB)

    Carle, S F; Maxwell, R M; Pawloski, G A; Shumaker, D E; Tompson, A B; Zavarin, M

    2006-12-12

    The objective of Phase II HST work is to develop a better understanding of the evolution of the HST for 1,000 years at the CAMBRIC underground nuclear test site in Frenchman Flat at the NTS. This work provides a better understanding of activities as they actually occurred, incorporates improvements based on recent data acquisition, and provides a basis to use the CAMBRIC site for model validation and monitoring activities as required by the UGTA Project. CAMBRIC was the only test in Frenchman Flat detonated under the water table and best represents a fully saturated environment. These simulations are part of a broad Phase II Frenchman Flat Corrective Action Unit (CAU) flow and transport modeling effort being conducted by the Department of Energy (DOE) Underground Test Area (UGTA) Project. HST simulations provide, either directly or indirectly, the source term used in the CAU model to calculate a contaminant boundary. Work described in this report augments Phase I HST calculations at CAMBRIC conducted by Tompson et al. (1999) and Pawloski et al. (2001). Phase II HST calculations have been organized to calculate source terms under two scenarios: (1) A representation of the transient flow and radionuclide release behavior at the CAMBRIC site that is more specific than Tompson et al. (1999). This model reflects the influence of the background hydraulic gradient, residual test heat, pumping experiment, and ditch recharge, and takes into account improved data sources and modeling approaches developed since the previous efforts. Collectively, this approach will be referred to as the transient CAMBRIC source term. This report describes the development of the transient CAMBRIC HST. (2) A generic release model made under steady-state flow conditions, in the absence of any transient effects, at the same site with the same radiologic source term. This model is for use in the development of simpler release models for the other nine underground test sites in the Frenchman Flat

  20. Long-term studies with the Ariel 5 ASM. 2: The strong Cygnus sources

    Science.gov (United States)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300-day record from the Ariel 5 All Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3.

  1. Bayesian Inference for Source Term Estimation: Application to the International Monitoring System Radionuclide Network

    Science.gov (United States)

    2014-10-01

    probability theory, Ecological Modeling, 205, 437–452. [10] Keats, A., Yee, E., and Lien, F.-S. (2010), Information-driven receptor placement for... Aerodynamics , 96, 1805–1816. [12] Yee, E. (2008), Theory for reconstruction of an unknown number of contaminant sources using probabilistic inference

  2. Evaluation of the long-rang dispersion of radionuclides from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Suh, K.S.; Jeong, H.J.; Kim, E.H.; Hwang, W.T.; Han, M.H. [Korea Atomic Energy Research Institute (KAERI), Nuclear Environmental Research Div., Daejeon (Korea, Republic of)

    2006-07-01

    The atmospheric dispersion models have been developed to predict and minimize the radiological damage for the surrounding environment since the Chernobyl accident. There are many nuclear power plants in the region of Northeast Asia. It is necessary to develop a long-range atmospheric dispersion model for the radiological emergency preparedness against a nuclear accident. From this viewpoint, a Lagrangian particle model named L.A.D.A.S.(Long-range Accident Dose Assessment System) was initially developed for the evaluation the long-range dispersion in Korea since 2001. The model designed to estimate air concentrations and dry deposition as well as wet deposition at distances up to some thousands of kilometers from the source point in a horizontal direction. The validation study of the model was firstly performed by comparing the measured values of E.T.E.X. exercise. The developed model was also applied to simulate the movements of the radioactive materials at the Chernobyl accident. An intercomparison and validation study among the long-range models was performed through the A.T.M.E.S.(Atmospheric Transport Model Evaluation Study) project under auspices of the IAEA/W.M.O. (world meteorological organization) in 1992. As a consequence of A.T.M.E.S., it was observed that in a real emergency case, under conditions of urgency and stress, many of the models would have had different results. So, one of the main recommendations was the launch of a long-range atmospheric tracer experiment in conditions as close as possible to those which could be found in a real emergency case, with the advantage of a complete knowledge of the source term. In this study, numerical simulations were carried out to estimate the concentration distributions of {sup 137}Cs. The calculated results agreed well with them by Chernobyl accident. In conclusion, a three dimensional Lagrangian particle model named L.A.D.A.S. was developed to evaluate the characteristics of a long-range atmospheric

  3. Long-Term Variability in Sugarcane Bagasse Feedstock Compositional Methods: Sources and Magnitude of Analytical Variability

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, David W.; Sluiter, Justin B.; Sluiter, Amie; Payne, Courtney; Crocker, David P.; Tao, Ling; Wolfrum, Ed

    2016-10-18

    In an effort to find economical, carbon-neutral transportation fuels, biomass feedstock compositional analysis methods are used to monitor, compare, and improve biofuel conversion processes. These methods are empirical, and the analytical variability seen in the feedstock compositional data propagates into variability in the conversion yields, component balances, mass balances, and ultimately the minimum ethanol selling price (MESP). We report the average composition and standard deviations of 119 individually extracted National Institute of Standards and Technology (NIST) bagasse [Reference Material (RM) 8491] run by seven analysts over 7 years. Two additional datasets, using bulk-extracted bagasse (containing 58 and 291 replicates each), were examined to separate out the effects of batch, analyst, sugar recovery standard calculation method, and extractions from the total analytical variability seen in the individually extracted dataset. We believe this is the world's largest NIST bagasse compositional analysis dataset and it provides unique insight into the long-term analytical variability. Understanding the long-term variability of the feedstock analysis will help determine the minimum difference that can be detected in yield, mass balance, and efficiency calculations. The long-term data show consistent bagasse component values through time and by different analysts. This suggests that the standard compositional analysis methods were performed consistently and that the bagasse RM itself remained unchanged during this time period. The long-term variability seen here is generally higher than short-term variabilities. It is worth noting that the effect of short-term or long-term feedstock compositional variability on MESP is small, about $0.03 per gallon. The long-term analysis variabilities reported here are plausible minimum values for these methods, though not necessarily average or expected variabilities. We must emphasize the importance of training and

  4. Criticality accident detector coverage analysis using the Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Zino, J.F.; Okafor, K.C.

    1993-12-31

    As a result of the need for a more accurate computational methodology, the Los Alamos developed Monte Carlo code MCNP is used to show the implementation of a more advanced and accurate methodology in criticality accident detector analysis. This paper will detail the application of MCNP for the analysis of the areas of coverage of a criticality accident alarm detector located inside a concrete storage vault at the Savannah River Site. The paper will discuss; (1) the generation of fixed-source representations of various criticality fission sources (for spherical geometries); (2) the normalization of these sources to the ``minimum criticality of concern`` as defined by ANS 8.3; (3) the optimization process used to determine which source produces the lowest total detector response for a given set of conditions; and (4) the use of this minimum source for the analysis of the areas of coverage of the criticality accident alarm detector.

  5. [Drowning accidents in childhood].

    Science.gov (United States)

    Krandick, G; Mantel, K

    1990-09-30

    This is a report on five boys aged between 1 and 5 years who, after prolonged submersion in cold water, were treated at our department. On being taken out of the water, all the patients were clinically dead. After 1- to 3-hour successful cardiopulmonary resuscitation, with a rectal temperature of about 27 degrees C, they were rewarmed at a rate of 1 degree/hour. Two patients died within a few hours after the accident. One patient survived with an apallic syndrome, 2 children survived with no sequelae. In the event of a water-related accident associated with hypothermia, we consider suitable resuscitation to have preference over rewarming measures. The most important treatment guidelines and prognostic factors are discussed.

  6. Study of the source term of radiation of the CDTN GE-PET trace 8 cyclotron with the MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Benavente C, J. A.; Lacerda, M. A. S.; Fonseca, T. C. F.; Da Silva, T. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Vega C, H. R., E-mail: jhonnybenavente@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    Full text: The knowledge of the neutron spectra in a PET cyclotron is important for the optimization of radiation protection of the workers and individuals of the public. The main objective of this work is to study the source term of radiation of the GE-PET trace 8 cyclotron of the Development Center of Nuclear Technology (CDTN/CNEN) using computer simulation by the Monte Carlo method. The MCNPX version 2.7 code was used to calculate the flux of neutrons produced from the interaction of the primary proton beam with the target body and other cyclotron components, during 18F production. The estimate of the source term and the corresponding radiation field was performed from the bombardment of a H{sub 2}{sup 18}O target with protons of 75 μA current and 16.5 MeV of energy. The values of the simulated fluxes were compared with those reported by the accelerator manufacturer (GE Health care Company). Results showed that the fluxes estimated with the MCNPX codes were about 70% lower than the reported by the manufacturer. The mean energies of the neutrons were also different of that reported by GE Health Care. It is recommended to investigate other cross sections data and the use of physical models of the code itself for a complete characterization of the source term of radiation. (Author)

  7. RENEB accident simulation exercise

    OpenAIRE

    Brzozowska, Beata; Ainsbury, Elizabeth; Baert, Annelot; Beaton-Green, Lindsay; Barrios, Leonardo; Barquinero, Joan Francesc; Bassinet, Celine; Beinke, Christina; Benedek, Anett; Beukes, Philip; Bortolin, Emanuela; Buraczewska, Iwona; Burbidge, Christopher; De Amicis, Andrea; De Angelis, Cinzia

    2017-01-01

    Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results ob...

  8. Aircraft Accident Prevention: Loss-of-Control Analysis

    Science.gov (United States)

    Kwatny, Harry G.; Dongmo, Jean-Etienne T.; Chang, Bor-Chin; Bajpai, Guarav; Yasar, Murat; Belcastro, Christine M.

    2009-01-01

    The majority of fatal aircraft accidents are associated with loss-of-control . Yet the notion of loss-of-control is not well-defined in terms suitable for rigorous control systems analysis. Loss-of-control is generally associated with flight outside of the normal flight envelope, with nonlinear influences, and with an inability of the pilot to control the aircraft. The two primary sources of nonlinearity are the intrinsic nonlinear dynamics of the aircraft and the state and control constraints within which the aircraft must operate. In this paper we examine how these nonlinearities affect the ability to control the aircraft and how they may contribute to loss-of-control. Examples are provided using NASA s Generic Transport Model.

  9. Dependence of maximum concentration from chemical accidents on release duration

    Science.gov (United States)

    Hanna, Steven; Chang, Joseph

    2017-01-01

    Chemical accidents often involve releases of a total mass, Q, of stored material in a tank over a time duration, td, of less than a few minutes. The value of td is usually uncertain because of lack of knowledge of key information, such as the size and location of the hole and the pressure and temperature of the chemical. In addition, it is rare that eyewitnesses or video cameras are present at the time of the accident. For inhalation hazards, serious health effects (such as damage to the respiratory system) are determined by short term averages (pressurized liquefied chlorine releases from tanks are given, focusing on scenarios from the Jack Rabbit I (JR I) field experiment. The analytical calculations and the predictions of the SLAB dense gas dispersion model agree that the ratio of maximum C for two different td's is greatest (as much as a factor of ten) near the source. At large distances (beyond a few km for the JR I scenarios), where tt exceeds both td's, the ratio of maximum C approaches unity.

  10. Developement of integrated evaluation system for severe accident management

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Ha; Kim, H. D.; Park, S. Y.; Kim, K. R.; Park, S. H.; Choi, Y.; Song, Y. M.; Ahn, K. I.; Park, J. H

    2005-04-01

    The scope of the project includes four activities such as construction of DB, development of data base management tool, development of severe accident analysis code system and FP studies. In the construction of DB, level-1,2 PSA results and plant damage states event trees were mainly used to select the following target initiators based on frequencies: LLOCA, MLOCA, SLOCA, station black out, LOOP, LOFW and SGTR. These scenarios occupy more than 95% of the total frequencies of the core damage sequences at KSNP. In the development of data base management tool, SARD 2.0 was developed under the PC microsoft windows environment using the visual basic 6.0 language. In the development of severe accident analysis code system, MIDAS 1.0 was developed with new features of FORTRAN-90 which makes it possible to allocate the storage dynamically and to use the user-defined data type, leading to an efficient memory treatment and an easy understanding. Also for user's convenience, the input (IEDIT) and output (IPLOT) processors were developed and implemented into the MIDAS code. For the model development of MIDAS concerning the FP behavior, the one dimensional thermophoresis model was developed and it gave much improvement to predict the amount of FP deposited on the SG U-tube. Also the source term analysis methodology was set up and applied to the KSNP and APR1400.

  11. Shielding analysis of proton therapy accelerators: a demonstration using Monte Carlo-generated source terms and attenuation lengths.

    Science.gov (United States)

    Lai, Bo-Lun; Sheu, Rong-Jiun; Lin, Uei-Tyng

    2015-05-01

    Monte Carlo simulations are generally considered the most accurate method for complex accelerator shielding analysis. Simplified models based on point-source line-of-sight approximation are often preferable in practice because they are intuitive and easy to use. A set of shielding data, including source terms and attenuation lengths for several common targets (iron, graphite, tissue, and copper) and shielding materials (concrete, iron, and lead) were generated by performing Monte Carlo simulations for 100-300 MeV protons. Possible applications and a proper use of the data set were demonstrated through a practical case study, in which shielding analysis on a typical proton treatment room was conducted. A thorough and consistent comparison between the predictions of our point-source line-of-sight model and those obtained by Monte Carlo simulations for a 360° dose distribution around the room perimeter showed that the data set can yield fairly accurate or conservative estimates for the transmitted doses, except for those near the maze exit. In addition, this study demonstrated that appropriate coupling between the generated source term and empirical formulae for radiation streaming can be used to predict a reasonable dose distribution along the maze. This case study proved the effectiveness and advantage of applying the data set to a quick shielding design and dose evaluation for proton therapy accelerators.

  12. PREVENTION OF OCCUPATIONAL ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Jovica Jovanovic

    2004-01-01

    Full Text Available Medical services, physicians and nurses play an essential role in the plant safety program through primary treatment of injured workers and by helping to identify workplace hazards. The physician and nurse should participate in the worksite investigations to identify specific hazard or stresses potentially causing the occupational accidents and injuries and in planning the subsequent hazard control program. Physicians and nurses must work closely and cooperatively with supervisors to ensure the prompt reporting and treatment of all work related health and safety problems. Occupational accidents, work related injuries and fatalities result from multiple causes, affect different segments of the working population, and occur in a myriad of occupations and industrial settings. Multiple factors and risks contribute to traumatic injuries, such as hazardous exposures, workplace and process design, work organization and environment, economics, and other social factors. With such a diversity of theories, it will not be difficult to understand that there does not exist one single theory that is considered right or correct and is universally accepted. These theories are nonetheless necessary, but not sufficient, for developing a frame of reference for understanding accident occurrences. Prevention strategies are also varied, and multiple strategies may be applicable to many settings, including engineering controls, protective equipment and technologies, management commitment to and investment in safety, regulatory controls, and education and training. Research needs are thus broad, and the development and application of interventions involve many disciplines and organizations.

  13. Short-term power sources for tokamaks and other physical experiments

    Energy Technology Data Exchange (ETDEWEB)

    Zajac, Jaromir [Institute of Plasma Physics, Za Slovankou 3, P.O. Box 17, 18221 Prague (Czech Republic)], E-mail: zajac@ipp.cas.cz; Zacek, Frantisek; Lejsek, Vojtech; Brettschneider, Zbynek [Institute of Plasma Physics, Za Slovankou 3, P.O. Box 17, 18221 Prague (Czech Republic)

    2007-06-15

    The Compass-D tokamak is being planned to move from UKAEA Culham (England) be and reinstalled in IPP Prague (Czech Republic). An overview of Compass-D energetics is described in short. The new power sources have to be designed. Alternative solutions of power sources have been investigated. Ignitrons and mechanical breakers can be replaced by modern high-power semiconductors. With respect to the need of accumulated energy, new technologies of energy storage - supercapacitors and high-speed flywheels, not applied up to now in similar fusion projects, are characterized in comparison with traditional ones - capacitors and big motor-flywheel generators. It is shown that these technologies enhance possibilities in arrangement of power supplies for tokamaks as well as for other high-power demanding experiments with pulse length from fraction to tens of seconds.

  14. Analysis of Credible Accidents for Argonaut Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, S. C.; Kathern, R. L.; Robkin, M. A.

    1981-04-01

    Five areas of potential accidents have been evaluated for the Argonaut-UTR reactors. They are: • insertion of excess reactivity • catastrophic rearrangement of the core • explosive chemical reaction • graphite fire • fuel-handling accident. A nuclear excursion resulting from the rapid insertion of the maximum available excess reactivity would produce only 12 MWs which is insufficient to cause fuel melting even with conservative assumptions. Although precise structural rearrangement of the core would create a potential hazard, it is simply not credible to assume that such an arrangement would result from the forces of an earthquake or other catastrophic event. Even damage to the fuel from falling debris or other objects is unlikely given the normal reactor structure. An explosion from a metal-water reaction could not occur because there is no credible source of sufficient energy to initiate the reaction. A graphite fire could conceivably create some damage to the reactor but not enough to melt any fuel or initiate a metal-water reaction. The only credible accident involving offsite doses was determined to be a fuel-handling accident which, given highly conservative assumptions, would produce a whole-body dose equivalent of 2 rem from noble gas immersion and a lifetime dose equivalent commitment to the thyroid of 43 rem from radioiodines.

  15. ANS severe accident program overview & planning document

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, R.P.

    1995-09-01

    The Advanced Neutron Source (ANS) severe accident document was developed to provide a concise and coherent mechanism for presenting the ANS SAP goals, a strategy satisfying these goals, a succinct summary of the work done to date, and what needs to be done in the future to ensure timely licensability. Guidance was received from various bodies [viz., panel members of the ANS severe accident workshop and safety review committee, Department of Energy (DOE) orders, Nuclear Regulatory Commission (NRC) requirements for ALWRs and advanced reactors, ACRS comments, world-wide trends] were utilized to set up the ANS-relevant SAS goals and strategy. An in-containment worker protection goal was also set up to account for the routine experimenters and other workers within containment. The strategy for achieving the goals is centered upon closing the severe accident issues that have the potential for becoming certification issues when assessed against realistic bounding events. Realistic bounding events are defined as events with an occurrency frequency greater than 10{sup {minus}6}/y. Currently, based upon the level-1 probabilistic risk assessment studies, the realistic bounding events for application for issue closure are flow blockage of fuel element coolant channels, and rapid depressurization-related accidents.

  16. COMPARATIVE ANALYSIS OF SOME HEALTH INDICATORS OF VARIOUS RADIATION ACCIDENTS LIQUIDATORS

    Directory of Open Access Journals (Sweden)

    V. M. Shubik

    2010-01-01

    Full Text Available The article presents the results of comparative investigation of morbidity and immunity of liquidators of radiation accidents occurred in South Urals (Kyshtym accident, at Chernobyl NPP and nuclear submarines (NS consequences. The most evident immunity and health changes were revealed for liquidators of Chernobyl NPP accident (ChNPP. Investigations of Kyshtym accident liquidators revealed long-term immunological losses. Comparison of health indicators of Chernobyl and nuclear submarine accident liquidators reveals the possibility of combined influence of radiation and stress on the immunity and health.

  17. 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

  18. Aquifers survey in the context of source rocks exploitation: from baseline acquisition to long term monitoring

    Science.gov (United States)

    Garcia, Bruno; Rouchon, Virgile; Deflandre, Jean-Pierre

    2017-04-01

    Producing hydrocarbons from source rocks (like shales: a mix of clays, silts, carbonate and sandstone minerals containing matured organic matter, i.e. kerogen oil and gas, but also non-hydrocarbon various species of chemical elements including sometimes radioactive elements) requires to create permeability within the rock matrix by at least hydraulically fracturing the source rock. It corresponds to the production of hydrocarbon fuels that have not been naturally expelled from the pressurized matured source rock and that remain trapped in the porosity or/and kerogen porosity of the impermeable matrix. Azimuth and extent of developed fractures can be respectively determined and mapped by monitoring the associated induced microseismicity. This allows to have an idea of where and how far injected fluids penetrated the rock formation. In a geological context, aquifers are always present in the vicinity -or on fluid migration paths- of such shale formations: deep aquifers (near the shale formation) up to sub-surface and potable (surface) aquifers. Our purpose will be to track any unsuitable invasion or migration of chemicals specifies coming from matured shales of production fluids including both drilling and fracturing ones into aquifers. Our objective is to early detect and alarm of any anomaly to avoid any important environmental issue. The approach consists in deploying a specific sampling tool within a well to recover formation fluids and to run a panoply of appropriate laboratory tests to state on fluid characteristics. Of course for deep aquifers, such a characterization process may consider aquifer properties prior producing shale oil and gas, as they may contain naturally some chemical species present in the source rocks. One can also consider that a baseline acquisition could be justified in case of possible previous invasion of non-natural fluids in the formation under survey (due to any anthropogenic action at surface or in the underground). The paper aims

  19. Severe Accidents and New Reactors. Twenty Years of Research; Accidents severos y nuevos reactores. Veinte anos de investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Jimenez, J.

    2008-07-01

    A review was done on the main activities performed by the Programme for Nuclear Safety of CIEMAT in the field of nuclear reactor safety from 1985 to 2005. It covers the areas of severe accident and source term, advanced and passive reactors, containments analyses and plant applications. It is emphasized CIEMATs participation in national and international projects mainly in those supported by CSN, OECD and the EU. At the same time, experimental and analytical capabilities set up at CIEMAT, as PECA, RECA and GIRS for simulating aerosol pool scrubbing phenomena, hydrogen catalytic recombiner and sprays are been presented, together with an Annex on Generation IV. Two chapters were added, one on the nuclear power reactors in the world and another about the safety systems and principles. (Author)

  20. Identification of sources and long term trends for pollutants in the arctic using isentropic trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mahura, A.; Jaffe, D.; Harris, J.

    2003-07-01

    The understanding of factors driving climate and ecosystem changes in the Arctic requires careful consideration of the sources, correlation and trends for anthropogenic pollutants. The database from the NOAA-CMDL Barrow Observatory (71deg.17'N, 156deg.47'W) is the longest and most complete record of pollutant measurements in the Arctic. It includes observations of carbon dioxide (CO{sub 2}), methane (CH{sub 4}), carbon monoxide (CO), ozone (O{sub 3}), aerosol scattering coefficient ({sigma}{sub sp}), aerosol number concentration (NC{sub asl}), etc. The objectives of this study are to understand the role of long-range transport to Barrow in explaining: (1) the year-to-year variations, and (2) the trends in the atmospheric chemistry record at the NOAA-CMDL Barrow observatory. The key questions we try to answer are: 1. What is the relationship between various chemical species measured at Barrow Observatory, Alaska and transport pathways at various altitudes? 2. What are the trends of species and their relation to transport patterns from the source regions? 3. What is the impact of the Prudhoe Bay emissions on the Barrow's records? To answer on these questions we apply the following main research tools. First, it is an isentropic trajectory model used to calculate the trajectories arriving at Barrow at three altitudes of 0.5, 1.5 and 3 km above sea level. Second - clustering procedure used to divide the trajectories into groups based on source regions. Third - various statistical analysis tools such as the exploratory data analysis, two component correlation analysis, trend analysis, principal components and factor analysis used to identify the relationship between various chemical species vs. source regions as a function of time. In this study, we used the chemical data from the NOAA-CMDL Barrow observatory in combination with isentropic backward trajectories from gridded ECMWF data to understand the importance of various pollutant source regions on

  1. Analysis of Large Release Source Terms in AP1000 Nuclear Power Plant%AP1000核电厂大量放射性释放源项分析

    Institute of Scientific and Technical Information of China (English)

    张琨

    2012-01-01

    在AP1000核电厂的某些严重事故情景中,安全壳可能发生失效或旁通,导致大量放射性物质释放到环境中,造成严重的放射性污染.针对大量放射性释放频率贡献最大的3种释放类别(安全壳旁通、安全壳早期失效和安全壳隔离失效),分别选取典型的严重事故序列(蒸汽发生器传热管破裂、自动卸压系统阀门误开启和压力容器破裂),使用MAAP程序计算分析了释放到环境中的裂变产物源项.该分析结果为量化AP1000核电厂的放射性释放后果和厂外剂量分析提供了必要的输入.%In some severe accident scenarios of AP1000 nuclear power plant, a breach or bypass of the containment will lead to large release to environment, which causes severe radioactive pollution of environment. Three release categories (bypass, early containment failure and containment isolation failure) have the largest contribution to large release frequency. Three typical severe accidents (steam generator tube rupture, spuriously open of automatic depressurization system valves and reactor pressure vessel rupture) were selected as typical cases corresponding to the three release categories and the fission-product source terms released to environment were calculated using MAAP code. The analysis results are provided as essential input data for quantifying the release of AP1000 nuclear power plant and the offsite dose analysis.

  2. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  3. Nodal Green’s Function Method Singular Source Term and Burnable Poison Treatment in Hexagonal Geometry

    Energy Technology Data Exchange (ETDEWEB)

    A.A. Bingham; R.M. Ferrer; A.M. ougouag

    2009-09-01

    An accurate and computationally efficient two or three-dimensional neutron diffusion model will be necessary for the development, safety parameters computation, and fuel cycle analysis of a prismatic Very High Temperature Reactor (VHTR) design under Next Generation Nuclear Plant Project (NGNP). For this purpose, an analytical nodal Green’s function solution for the transverse integrated neutron diffusion equation is developed in two and three-dimensional hexagonal geometry. This scheme is incorporated into HEXPEDITE, a code first developed by Fitzpatrick and Ougouag. HEXPEDITE neglects non-physical discontinuity terms that arise in the transverse leakage due to the transverse integration procedure application to hexagonal geometry and cannot account for the effects of burnable poisons across nodal boundaries. The test code being developed for this document accounts for these terms by maintaining an inventory of neutrons by using the nodal balance equation as a constraint of the neutron flux equation. The method developed in this report is intended to restore neutron conservation and increase the accuracy of the code by adding these terms to the transverse integrated flux solution and applying the nodal Green’s function solution to the resulting equation to derive a semi-analytical solution.

  4. Long-term studies with the Ariel 5 ASM. II - The strong Cygnus sources

    Science.gov (United States)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300 day record from the Ariel 5 All-Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3. The 78.4 day period of Kemp, Herman, and Barbour for Cyg X-1, the 9.843 day period of Cowley, Crampton, and Hutchings for Cyg X-2, and the 16.75 day period of Holt et al. for Cyg X-3 are not confirmed.

  5. LEAK: A source term generator for evaluating release rates from leaking vessels

    Energy Technology Data Exchange (ETDEWEB)

    Clinton, J.H.

    1994-09-01

    An interactive computer code for estimating the rate of release of any one of several materials from a leaking tank or broken pipe leading from a tank is presented. It is generally assumed that the material in the tank is liquid. Materials included in the data base are acetonitrile, ammonia, carbon tetrachloride, chlorine, chlorine trifluoride, fluorine, hydrogen fluoride, nitric acid, nitrogen tetroxide, sodium hydroxide, sulfur hexafluoride, sulfuric acid, and uranium hexafluoride. Materials that exist only as liquid and/or vapor over expected ranges of temperature and pressure can easily be added to the data base file. The Fortran source code for LEAK and the data file are included with this report.

  6. An Iterative Regularization Method for Identifying the Source Term in a Second Order Differential Equation

    Directory of Open Access Journals (Sweden)

    Fairouz Zouyed

    2015-01-01

    Full Text Available This paper discusses the inverse problem of determining an unknown source in a second order differential equation from measured final data. This problem is ill-posed; that is, the solution (if it exists does not depend continuously on the data. In order to solve the considered problem, an iterative method is proposed. Using this method a regularized solution is constructed and an a priori error estimate between the exact solution and its regularized approximation is obtained. Moreover, numerical results are presented to illustrate the accuracy and efficiency of this method.

  7. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    Science.gov (United States)

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power.

  8. Asymptotically and exactly energy balanced augmented flux-ADER schemes with application to hyperbolic conservation laws with geometric source terms

    Science.gov (United States)

    Navas-Montilla, A.; Murillo, J.

    2016-07-01

    In this work, an arbitrary order HLL-type numerical scheme is constructed using the flux-ADER methodology. The proposed scheme is based on an augmented Derivative Riemann solver that was used for the first time in Navas-Montilla and Murillo (2015) [1]. Such solver, hereafter referred to as Flux-Source (FS) solver, was conceived as a high order extension of the augmented Roe solver and led to the generation of a novel numerical scheme called AR-ADER scheme. Here, we provide a general definition of the FS solver independently of the Riemann solver used in it. Moreover, a simplified version of the solver, referred to as Linearized-Flux-Source (LFS) solver, is presented. This novel version of the FS solver allows to compute the solution without requiring reconstruction of derivatives of the fluxes, nevertheless some drawbacks are evidenced. In contrast to other previously defined Derivative Riemann solvers, the proposed FS and LFS solvers take into account the presence of the source term in the resolution of the Derivative Riemann Problem (DRP), which is of particular interest when dealing with geometric source terms. When applied to the shallow water equations, the proposed HLLS-ADER and AR-ADER schemes can be constructed to fulfill the exactly well-balanced property, showing that an arbitrary quadrature of the integral of the source inside the cell does not ensure energy balanced solutions. As a result of this work, energy balanced flux-ADER schemes that provide the exact solution for steady cases and that converge to the exact solution with arbitrary order for transient cases are constructed.

  9. 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.

  10. Long term leaching of chlorinated solvents from source zones in low permeability settings with fractures

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Chambon, Julie Claire Claudia; Troldborg, Mads

    2008-01-01

    accounting for competitive inhibition between the chlorinated ethenes. The model is constructed using Comsol Multiphysics, a generic finite- element partial differential equation solver. The model is applied at two well characterised field sites with respect to hydrogeology, fracture network, contaminant...... distribution and microbial processes (lab and field experiments). At the study sites (Sortebrovej and Vadsbyvej), the source areas are situated in a clayey till with fractures and interbedded sand lenses. The field sites are both highly contaminated with chlorinated ethenes which impact the underlying sand...... aquifer. Anaerobic dechlorination is taking place, and cis-DCE and VC have been found in significant amounts in the matrix. Full scale remediation using ERD was implemented at Sortebrovej in 2006, and ERD has been suggested as a remedy at Vadsbyvej. Results reveal several interesting findings...

  11. Comparative Investigation of Source Term Estimation Algorithms for Hazardous Material Atmospheric Transport and Dispersion Prediction Tools

    Science.gov (United States)

    2012-07-01

    DPD DPN DCD DCN 10 Appendix E provides additional plots of miss distance for single...Double-Source Releases 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 SPD SPN SCD SCN 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 DPD DPN DCD DCN E-5 Figure E-7. STE Algorithm...SPN DPD DPN 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 SCD SCN DCD DCN E-6 (This page is intentionally blank.) F-1 Appendix

  12. Extraction of temporal networks from term co-occurrences in online textual sources.

    Science.gov (United States)

    Popović, Marko; Štefančić, Hrvoje; Sluban, Borut; Kralj Novak, Petra; Grčar, Miha; Mozetič, Igor; Puliga, Michelangelo; Zlatić, Vinko

    2014-01-01

    A stream of unstructured news can be a valuable source of hidden relations between different entities, such as financial institutions, countries, or persons. We present an approach to continuously collect online news, recognize relevant entities in them, and extract time-varying networks. The nodes of the network are the entities, and the links are their co-occurrences. We present a method to estimate the significance of co-occurrences, and a benchmark model against which their robustness is evaluated. The approach is applied to a large set of financial news, collected over a period of two years. The entities we consider are 50 countries which issue sovereign bonds, and which are insured by Credit Default Swaps (CDS) in turn. We compare the country co-occurrence networks to the CDS networks constructed from the correlations between the CDS. The results show relatively small, but significant overlap between the networks extracted from the news and those from the CDS correlations.

  13. Quantification of long-term primary and secondary source contributions to carbonaceous aerosols.

    Science.gov (United States)

    Shi, Guoliang; Peng, Xing; Liu, Jiayuan; Tian, Yingze; Song, Danlin; Yu, Haofei; Feng, Yinchang; Russell, Armistead G

    2016-12-01

    Ambient fine particulate matter samples were collected during 2009-2013 in Chengdu, a megacity in western China, and the samples were speciated into organic carbon (OC), elemental carbon (EC), char-EC, soot-EC, eight carbon fractions, inorganic elements and water-soluble ions. Char-EC and soot-EC contribute to the better understanding of the sources and properties of EC. The highest levels of most carbon fractions were found in winter and May. The higher OC/EC ratio in winter suggests higher SOC fraction in winter, and higher char-EC/soot-EC ratio in May are the direct consequences of straw burning activities. Source contributions to PM2.5 and carbonaceous aerosols were quantified using the ME2 receptor model. Major contributors to OC in PM2.5 are vehicular exhaust (36.5%), coal combustion & straw burning (35.2%) and SOC (27.0%). The first two categories also contributed 51.4% and 49.3% of char-EC in PM2.5. Vehicular exhaust dominated soot-EC, contributing 63.0% to soot-EC in PM2.5. SOC contributed to high OC levels in winter due to the increase of precursor emissions and stable meteorological conditions. Coal combustion & straw burning show higher contributions to OC, char-EC and soot-EC in winter months and in May, which can be explained, in part, by increased coal consumption in winter and straw burning activities in May. Vehicular exhaust contributions are not strongly associated with monthly nor weekday-weekend patterns, resulting in that soot-EC vary insignificantly by month nor by weekday.

  14. Coming to Terms: A conflict analysis of the usage, in official and unofficial sources, of 'security fence', 'apartheid wall', and other terms for the structure between Israel and the Palestinian Territories

    NARCIS (Netherlands)

    Rogers, R.A.; Ben-David, A.

    2010-01-01

    The official terms for the dividing wall are ‘security fence’ on the Israeli side and ‘apartheid wall’ on the Palestinian side. Both terms fuse two contextually charged notions to describe the construction project. Beyond the two official terms, the structure has been given other names by sources ap

  15. A simplified radionuclide source term for total-system performance assessment; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.L.

    1991-11-01

    A parametric model for releases of radionuclides from spent-nuclear-fuel containers in a waste repository is presented. The model is appropriate for use in preliminary total-system performance assessments of the potential repository site at Yucca Mountain, Nevada; for this reason it is simpler than the models used for detailed studies of waste-package performance. Terms are included for releases from the spent fuel pellets, from the pellet/cladding gap and the grain boundaries within the fuel pellets, from the cladding of the fuel rods, and from the radioactive fuel-assembly parts. Multiple barriers are considered, including the waste container, the fuel-rod cladding, the thermal ``dry-out``, and the waste form itself. The basic formulas for release from a single fuel rod or container are extended to formulas for expected releases for the whole repository by using analytic expressions for probability distributions of some important parameters. 39 refs., 4 figs., 4 tabs.

  16. Long-term monitoring of airborne nickel (Ni) pollution in association with some potential source processes in the urban environment.

    Science.gov (United States)

    Kim, Ki-Hyun; Shon, Zang-Ho; Mauulida, Puteri T; Song, Sang-Keun

    2014-09-01

    The environmental behavior and pollution status of nickel (Ni) were investigated in seven major cities in Korea over a 13-year time span (1998-2010). The mean concentrations of Ni measured during the whole study period fell within the range of 3.71 (Gwangju: GJ) to 12.6ngm(-3) (Incheon: IC). Although Ni values showed a good comparability in a relatively large spatial scale, its values in most cities (6 out of 7) were subject to moderate reductions over the study period. To assess the effect of major sources on the long-term distribution of Ni, the relationship between their concentrations and the potent source processes like non-road transportation sources (e.g., ship and aircraft emissions) were examined from some cities with port and airport facilities. The potential impact of long-range transport of Asian dust particles in controlling Ni levels was also evaluated. The overall results suggest that the Ni levels were subject to gradual reductions over the study period irrespective of changes in such localized non-road source activities. The pollution of Ni at all the study sites was maintained well below the international threshold (Directive 2004/107/EC) value of 20ngm(-3).

  17. Advanced Monte Carlo procedure for the IFMIF d-Li neutron source term based on evaluated cross section data

    CERN Document Server

    Simakov, S P; Moellendorff, U V; Schmuck, I; Konobeev, A Y; Korovin, Y A; Pereslavtsev, P

    2002-01-01

    A newly developed computational procedure is presented for the generation of d-Li source neutrons in Monte Carlo transport calculations based on the use of evaluated double-differential d+ sup 6 sup , sup 7 Li cross section data. A new code M sup c DeLicious was developed as an extension to MCNP4C to enable neutronics design calculations for the d-Li based IFMIF neutron source making use of the evaluated deuteron data files. The M sup c DeLicious code was checked against available experimental data and calculation results of M sup c DeLi and MCNPX, both of which use built-in analytical models for the Li(d, xn) reaction. It is shown that M sup c DeLicious along with newly evaluated d+ sup 6 sup , sup 7 Li data is superior in predicting the characteristics of the d-Li neutron source. As this approach makes use of tabulated Li(d, xn) cross sections, the accuracy of the IFMIF d-Li neutron source term can be steadily improved with more advanced and validated data.

  18. Short-term spasmodic switching of volcanic tremor source activation in a conduit of the 2011 Kirishima eruption

    Science.gov (United States)

    Matsumoto, S.; Shimizu, H.; Matsushima, T.; Uehira, K.; Yamashita, Y.; Nakamoto, M.; Miyazaki, M.; Chikura, H.

    2012-04-01

    Volcanic tremors are seismic indicators providing clues for magma behavior, which is related to volcanic eruptions and activity. Detection of spatial and temporal variations of volcanic tremors is important for understanding the mechanism of volcanic eruptions. However, temporal variations of tremor activity in short-term than a minute have not been previously detected by seismological observations around volcanoes. Here, we show that volcanic tremor sources were activated at the top of the conduit (i.e. the crater) and at its lower end by analyzing seismograms from a dense seismic array during the 2011 Kirishima eruption. We observed spasmodic switching in the seismic ray direction during a volcanic tremor sequence. Such fine volcanic tremor structure suggests an interaction between tremor sources located in both deep and shallow depths. Our result suggests that seismic array observations can monitor the magma behavior and contribute to the evaluation of the activity's transition.

  19. Imbalance of energy and momentum source terms of the sea wave transfer equation for fully developed seas

    Directory of Open Access Journals (Sweden)

    G. V. Caudal

    2012-12-01

    Full Text Available In the concept of full development, the sea wave spectrum is regarded as a nearly stationary solution of the wave transfer equation, where source and sink terms should be in balance with respect to both energy and momentum. Using a two-dimensional empirical sea wave spectral model at full development, this paper performs an assessment of the compatibility of the energy and momentum budgets of sea waves over the whole spectral range. Among the various combinations of model functions for wave breaking and wind source terms tested, not one is found to fulfill simultaneously the energy and momentum balance of the transfer equation. Based on experimental and theoretical grounds, wave breaking is known to contribute to frequency downshift of a narrow-banded wave spectrum when the modulational instability is combined with wave breaking. On those grounds, it is assumed that, in addition to dissipation, wave breaking produces a spectral energy flux directed toward low wavenumbers. I show that it is then possible to remove the energy and momentum budget inconsistency, and correspondingly the required strength of this spectral flux is estimated. Introducing such a downward spectral flux permits fulfilling both energy and momentum balance conditions. Meanwhile, the consistency between the transfer equation and empirical spectra, estimated by means of a cost function K, is either improved or slightly reduced, depending upon the wave breaking and wind source terms chosen. Other tests are performed in which it is further assumed that wave breaking would also be associated with azimuthal diffusion of the spectral energy. This would correspondingly reduce the required downward spectral flux by a factor of up to 5, although it would not be able to remove it entirely.

  20. Review of Technical Issues Related to Predicting Isotopic Compositions and Source Terms for High-Burnup LWR Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gauld, I. C.; Parks, C. V.

    2000-12-11

    This report has been prepared to review the technical issues important to the prediction of isotopic compositions and source terms for high-burnup, light-water-reactor (LWR) fuel as utilized in the licensing of spent fuel transport and storage systems. The current trend towards higher initial 235U enrichments, more complex assembly designs, and more efficient fuel management schemes has resulted in higher spent fuel burnups than seen in the past. This trend has led to a situation where high-burnup assemblies from operating LWRs now extend beyond the area where available experimental data can be used to validate the computational methods employed to calculate spent fuel inventories and source terms. This report provides a brief review of currently available validation data, including isotopic assays, decay heat measurements, and shielded dose-rate measurements. Potential new sources of experimental data available in the near term are identified. A review of the background issues important to isotopic predictions and some of the perceived technical challenges that high-burnup fuel presents to the current computational methods are discussed. Based on the review, the phenomena that need to be investigated further and the technical issues that require resolution are presented. The methods and data development that may be required to address the possible shortcomings of physics and depletion methods in the high-burnup and high-enrichment regime are also discussed. Finally, a sensitivity analysis methodology is presented. This methodology is currently being investigated at the Oak Ridge National Laboratory as a computational tool to better understand the changing relative significance of the underlying nuclear data in the different enrichment and burnup regimes and to identify the processes that are dominant in the high-burnup regime. The potential application of the sensitivity analysis methodology to help establish a range of applicability for experimental

  1. Residual-based a posteriori error estimates of nonconforming finite element method for elliptic problems with Dirac delta source terms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Two residual-based a posteriori error estimators of the nonconforming Crouzeix-Raviart element are derived for elliptic problems with Dirac delta source terms.One estimator is shown to be reliable and efficient,which yields global upper and lower bounds for the error in piecewise W1,p seminorm.The other one is proved to give a global upper bound of the error in Lp-norm.By taking the two estimators as refinement indicators,adaptive algorithms are suggested,which are experimentally shown to attain optimal convergence orders.

  2. Characterization and long term operation of a novel superconducting undulator with 15 mm period length in a synchrotron light source

    Science.gov (United States)

    Casalbuoni, S.; Cecilia, A.; Gerstl, S.; Glamann, N.; Grau, A. W.; Holubek, T.; Meuter, C.; de Jauregui, D. Saez; Voutta, R.; Boffo, C.; Gerhard, Th.; Turenne, M.; Walter, W.

    2016-11-01

    A new cryogen-free full scale (1.5 m long) superconducting undulator with a period length of 15 mm (SCU15) has been successfully tested in the ANKA storage ring. This represents a very important milestone in the development of superconducting undulators for third and fourth generation light sources carried on by the collaboration between the Karlsruhe Institute of Technology and the industrial partner Babcock Noell GmbH. SCU15 is the first full length device worldwide that with beam reaches a higher peak field than what expected with the same geometry (vacuum gap and period length) with an ideal cryogenic permanent magnet undulator built with the best material available PrFeB. After a summary on the design and main parameters of the device, we present here the characterization in terms of spectral properties and the long term operation of the SCU15 in the ANKA storage ring.

  3. Measurement and apportionment of radon source terms for modeling indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor [sup 222]Rn and in [sup 222]Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house [sup 222]Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater [sup 222]Rn concentration than the measured outdoor [sup 222]Rn. Apartment dwellers generally represent a low risk group regarding [sup 222]Rn exposure. The following sections describe the main projects in some detail.

  4. Extraction of temporal networks from term co-occurrences in online textual sources.

    Directory of Open Access Journals (Sweden)

    Marko Popović

    Full Text Available A stream of unstructured news can be a valuable source of hidden relations between different entities, such as financial institutions, countries, or persons. We present an approach to continuously collect online news, recognize relevant entities in them, and extract time-varying networks. The nodes of the network are the entities, and the links are their co-occurrences. We present a method to estimate the significance of co-occurrences, and a benchmark model against which their robustness is evaluated. The approach is applied to a large set of financial news, collected over a period of two years. The entities we consider are 50 countries which issue sovereign bonds, and which are insured by Credit Default Swaps (CDS in turn. We compare the country co-occurrence networks to the CDS networks constructed from the correlations between the CDS. The results show relatively small, but significant overlap between the networks extracted from the news and those from the CDS correlations.

  5. DRINK: a biogeochemical source term model for low level radioactive waste disposal sites.

    Science.gov (United States)

    Humphreys, P; McGarry, R; Hoffmann, A; Binks, P

    1997-07-01

    Interactions between element chemistry and the ambient geochemistry play a significant role in the control of radionuclide migration in the geosphere. These same interactions influence radionuclide release from near surface, low level radioactive waste, disposal sites once physical containment has degraded. In situations where LLW contains significant amounts of metal and organic materials such as cellulose, microbial degradation in conjunction with corrosion can significantly perturb the ambient geochemistry. These processes typically produce a transition from oxidising to reducing conditions and can influence radionuclide migration through changes in both the dominant radionuclide species and mineral phases. The DRINK (DRIgg Near field Kinetic) code is a biogeochemical transport code designed to simulate the long term evolution of the UK low level radioactive waste disposal site at Drigg. Drigg is the UK's principal solid low level radioactive waste disposal site and has been receiving waste since 1959. The interaction between microbial activity, the ambient geochemistry and radionuclide chemistry is central to the DRINK approach with the development of the ambient pH, redox potential and bulk geochemistry being directly influenced by microbial activity. This paper describes the microbial aspects of the code, site data underpinning the microbial model, the microbiology/chemistry interface and provides an example of the code in action.

  6. Comparative Assessment Of Natural Gas Accident Risks

    Energy Technology Data Exchange (ETDEWEB)

    Burgherr, P.; Hirschberg, S

    2005-01-01

    The study utilizes a hierarchical approach including (1) comparative analyses of different energy chains, (2) specific evaluations for the natural gas chain, and (3) a detailed overview of the German situation, based on an extensive data set provided by Deutsche Vereinigung des Gas- und Wasserfaches (DVGW). According to SVGW-expertise DVGW-data can be regarded as fully representative for Swiss conditions due to very similar technologies, management, regulations and safety culture, but has a substantially stronger statistical basis because the German gas grid is about 30 times larger compared to Switzerland. Specifically, the following tasks were carried out by PSI to accomplish the objectives of this project: (1) Consolidation of existing ENSAD data, (2) identification and evaluation of additional sources, (3) comparative assessment of accident risks, and (4) detailed evaluations of specific issues and technical aspects for severe and smaller accidents in the natural gas chain that are relevant under Swiss conditions. (author)

  7. Long-term Science Data Curation Using a Digital Object Model and Open-Source Frameworks

    Science.gov (United States)

    Pan, J.; Lenhardt, W.; Wilson, B. E.; Palanisamy, G.; Cook, R. B.

    2010-12-01

    Scientific digital content, including Earth Science observations and model output, has become more heterogeneous in format and more distributed across the Internet. In addition, data and metadata are becoming necessarily linked internally and externally on the Web. As a result, such content has become more difficult for providers to manage and preserve and for users to locate, understand, and consume. Specifically, it is increasingly harder to deliver relevant metadata and data processing lineage information along with the actual content consistently. Readme files, data quality information, production provenance, and other descriptive metadata are often separated in the storage level as well as in the data search and retrieval interfaces available to a user. Critical archival metadata, such as auditing trails and integrity checks, are often even more difficult for users to access, if they exist at all. We investigate the use of several open-source software frameworks to address these challenges. We use Fedora Commons Framework and its digital object abstraction as the repository, Drupal CMS as the user-interface, and the Islandora module as the connector from Drupal to Fedora Repository. With the digital object model, metadata of data description and data provenance can be associated with data content in a formal manner, so are external references and other arbitrary auxiliary information. Changes are formally audited on an object, and digital contents are versioned and have checksums automatically computed. Further, relationships among objects are formally expressed with RDF triples. Data replication, recovery, metadata export are supported with standard protocols, such as OAI-PMH. We provide a tentative comparative analysis of the chosen software stack with the Open Archival Information System (OAIS) reference model, along with our initial results with the existing terrestrial ecology data collections at NASA’s ORNL Distributed Active Archive Center for

  8. Toronto area ozone: Long-term measurements and modeled sources of poor air quality events

    Science.gov (United States)

    Whaley, C. H.; Strong, K.; Jones, D. B. A.; Walker, T. W.; Jiang, Z.; Henze, D. K.; Cooke, M. A.; McLinden, C. A.; Mittermeier, R. L.; Pommier, M.; Fogal, P. F.

    2015-11-01

    The University of Toronto Atmospheric Observatory and Environment Canada's Centre for Atmospheric Research Experiments each has over a decade of ground-based Fourier transform infrared (FTIR) spectroscopy measurements in southern Ontario. We present the Toronto area FTIR time series from 2002 to 2013 of two tropospheric trace gases—ozone and carbon monoxide—along with surface in situ measurements taken by government monitoring programs. We interpret their variability with the GEOS-Chem chemical transport model and determine the atmospheric conditions that cause pollution events in the time series. Our analysis includes a regionally tagged O3 model of the 2004-2007 time period, which quantifies the geographical contributions to Toronto area O3. The important emission types for 15 pollution events are then determined with a high-resolution adjoint model. Toronto O3, during pollution events, is most sensitive to southern Ontario and U.S. fossil fuel NOx emissions and natural isoprene emissions. The sources of Toronto pollution events are found to be highly variable, and this is demonstrated in four case studies representing local, short-, middle-, and long-range transport scenarios. This suggests that continental-scale emission reductions could improve air quality in the Toronto region. We also find that abnormally high temperatures and high-pressure systems are common to all pollution events studied, suggesting that climate change may impact Toronto O3. Finally, we quantitatively compare the sensitivity of the surface and column measurements to anthropogenic NOx emissions and show that they are remarkably similar. This work thus demonstrates the usefulness of FTIR measurements in an urban area to assess air quality.

  9. Severe Accident Scoping Simulations of Accident Tolerant Fuel Concepts for BWRs

    Energy Technology Data Exchange (ETDEWEB)

    Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    CrAl would tend to generate heat and hydrogen from oxidation at a slower rate compared to the zirconium-based alloys in use today. The previous study, [2], of the FeCrAl ATF concept during station blackout (SBO) severe accident scenarios in BWRs was based on simulating short term SBO (STSBO), long term SBO (LTSBO), and modified SBO scenarios occurring in a BWR-4 reactor with MARK-I containment. The analysis indicated that FeCrAl had the potential to delay the onset of fuel failure by a few hours depending on the scenario, and it could delay lower head failure by several hours. The analysis demonstrated reduced in-vessel hydrogen production. However, the work was preliminary and was based on limited knowledge of material properties for FeCrAl. Limitations of the MELCOR code were identified for direct use in modeling ATF concepts. This effort used an older version of MELCOR (1.8.5). Since these analyses, the BWR model has been updated for use in MELCOR 1.8.6 [10], and more representative material properties for FeCrAl have been modeled. Sections 2 4 present updated analyses for the FeCrAl ATF concept response during severe accidents in a BWR. The purpose of the study is to estimate the potential gains afforded by the FeCrAl ATF concept during BWR SBO scenarios.

  10. Accidents on ships in the Danish International Ship register

    DEFF Research Database (Denmark)

    Ádám, Balázs; Rasmussen, Hanna Barbara

    Safety has been in the focus of seafaring during the past decade that observed a gradual reduction of reported work injuries in Danish ships. The injuries are, however, unevenly distributed in the maritime workforce, depending on various factors, the nationality of seafarer among them. The aim of...... the occurrence as well as the reporting of accidents is crucial to construct effective preventive measures for risk management....... to report accidents causing at least one day off work beyond the day of accident but the first source contains several accidents not fulfilling this criterion, too. Radio Medical is an independent service where all Danish ships may seek medical advice. The data sets were merged by identification number...... Western European seafarers compared to South East Asian (mostly Filipino) employees. The results highlight a favourable level of reported injuries in the Danish maritime sector but also point out detectable differences between groups of employees. The identification of factors that determine...

  11. Calculation reliability in vehicle accident reconstruction.

    Science.gov (United States)

    Wach, Wojciech

    2016-06-01

    The reconstruction of vehicle accidents is subject to assessment in terms of the reliability of a specific system of engineering and technical operations. In the article [26] a formalized concept of the reliability of vehicle accident reconstruction, defined using Bayesian networks, was proposed. The current article is focused on the calculation reliability since that is the most objective section of this model. It is shown that calculation reliability in accident reconstruction is not another form of calculation uncertainty. The calculation reliability is made dependent on modeling reliability, adequacy of the model and relative uncertainty of calculation. All the terms are defined. An example is presented concerning the analytical determination of the collision location of two vehicles on the road in the absence of evidential traces. It has been proved that the reliability of this kind of calculations generally does not exceed 0.65, despite the fact that the calculation uncertainty itself can reach only 0.05. In this example special attention is paid to the analysis of modeling reliability and calculation uncertainty using sensitivity coefficients and weighted relative uncertainty.

  12. Statistical analysis of sudden chemical leakage accidents reported in China between 2006 and 2011.

    Science.gov (United States)

    Li, Yang; Ping, Hua; Ma, Zhi-Hong; Pan, Li-Gang

    2014-04-01

    According to the data from authoritative sources, 1,400 sudden leakage accidents occurred in China during 2006 to 2011 were investigated, in which, 666 accidents were used for statistical characteristic abstracted with no or little damage. The research results were as follows: (1) Time fluctuation: the yearly number of sudden leakage accidents is shown to be decreasing from 2006 to 2010, and a slightly increase in 2011. Sudden leakage accidents occur mainly in summer, and more than half of the accidents occur from May to September. (2) Regional distribution: the accidents are highly concentrated in the coastal area, in which accidents result from small and medium-sized enterprises more easily than that of the larger ones. (3) Pollutants: hazardous chemicals are up to 95 % of sudden leakage accidents. (4) Steps: transportation represents almost half of the accidents, followed by production, usage, storage, and discard. (5) Pollution and casualties: it is easy to cause environmental pollution and casualties. (6) Causes: more than half of the cases were caused by human factor, followed by management reason, and equipment failure. However, sudden chemical leakage may also be caused by high temperature, rain, wet road, and terrain. (7) The results of principal component analysis: five factors are extracted by the principal component analysis, including pollution, casualties, regional distribution, steps, and month. According to the analysis of the accident, the characteristics, causes, and damages of the sudden leakage accident will be investigated. Therefore, advices for prevention and rescue should be acquired.

  13. Short-term microbial release during rain events from on-site sewers and cattle in a surface water source.

    Science.gov (United States)

    Aström, Johan; Pettersson, Thomas J R; Reischer, Georg H; Hermansson, Malte

    2013-09-01

    The protection of drinking water from pathogens such as Cryptosporidium and Giardia requires an understanding of the short-term microbial release from faecal contamination sources in the catchment. Flow-weighted samples were collected during two rainfall events in a stream draining an area with on-site sewers and during two rainfall events in surface runoff from a bovine cattle pasture. Samples were analysed for human (BacH) and ruminant (BacR) Bacteroidales genetic markers through quantitative polymerase chain reaction (qPCR) and for sorbitol-fermenting bifidobacteria through culturing as a complement to traditional faecal indicator bacteria, somatic coliphages and the parasitic protozoa Cryptosporidium spp. and Giardia spp. analysed by standard methods. Significant positive correlations were observed between BacH, Escherichia coli, intestinal enterococci, sulphite-reducing Clostridia, turbidity, conductivity and UV254 in the stream contaminated by on-site sewers. For the cattle pasture, no correlation was found between any of the genetic markers and the other parameters. Although parasitic protozoa were not detected, the analysis for genetic markers provided baseline data on the short-term faecal contamination due to these potential sources of parasites. Background levels of BacH and BacR makers in soil emphasise the need to including soil reference samples in qPCR-based analyses for Bacteroidales genetic markers.

  14. Imbalance of energy and momentum source terms of the sea wave transfer equation for fully developed seas

    Directory of Open Access Journals (Sweden)

    G. V. Caudal

    2012-07-01

    Full Text Available Using a two-dimensional empirical sea wave spectral model at full development, this paper performs an assessment of the compatibility of the energy and momentum budgets of sea waves over the whole spectral range. Among the various combinations of model functions for wave breaking and wind source terms tested, no one fulfilled simultaneously the energy and momentum balance of the transfer equation. Based on experimental and theoretical grounds, wave breaking is known to contribute to frequency downshift of a narrow-banded wave spectrum, when the modulational instability is combined with wave breaking. On those grounds, it is assumed that, in addition to dissipation, wave breaking produces a spectral energy flux directed toward low wavenumbers. I show that it is then possible to remove the energy and momentum budget inconsistency, and correlatively the required strength of this spectral flux is estimated. Assuming such a downward spectral flux permits to fulfill both energy and momentum balance conditions, while slightly reducing the consistency between source terms and empirical spectra, as estimated by a cost function K. Other tests were performed in which it was further assumed that wave breaking would also be associated with azimuthal diffusion of the spectral energy. This could allow a slight improvement of the cost function K, and might correlatively reduce the required downward spectral flux by a factor of 4, although it would not be able to remove it entirely.

  15. Sources of Divergence in Remote Sensing of Vegetation Phenology From Multiple Long Term Satellite Data Records

    Science.gov (United States)

    Barreto, A.; Didan, K.; Miura, T.

    2008-12-01

    Changes in vegetation phenology depict an integrated response to change in environmental factors and provide valuable information to global change research. Typically, remote sensing of vegetation phenology is based on the analysis of vegetation index temporal profiles, because of their simplicity, stability, and inherent resistant to noise. Most phenology estimates are, however, limited to using one sensor owing to the inter-sensor continuity challenges. Although, phenology is used for a variety of research and application topics, the central premise remains the study of vegetation dynamics change in response to change in climate and other factors. Consequently, the consistency and length of data records are key requirements. With satellite missions lasting few years only, long term phenology measures will have to be based on a mixture of satellite data records. In this study we compared phenology parameters from the AVHRR-GIMMS and MODIS NDVI records (1982- 2007). We analyzed both records globally using a cluster approach to abate noise and focus on the landscape level vegetation dynamic. The cluster approach, assumes that phenology is controlled by a complex set of factors that could be encapsulated by homogeneous climate, soil, elevational gradient, sun- shade exposure, and biophysical capacity. We applied this method to each of the sensors and examined three fundamental phenology parameters: the start and end of the growing season and the cumulative seasonal signal. These parameters are sensitive to, and are capable of capturing changes in the underlying environmental factors. Our results indicate that a large divergence exist over the dense forest of the tropics. This divergence was attributed to MODIS saturation rather than NDVI saturation. Boreal forests exhibited also large disagreement owing to snow cover and related differences in data processing. Furthermore, agricultural areas showed the most irregular phenological signals. This noise resulted from the

  16. Long-term Trends of Plot-scale Cs-137 Wash-off on Various Land Uses in the Area Affected by the Accident of Fukushima Dai-ichi Nuclear Power Plant

    Science.gov (United States)

    Wakiyama, Y.; Onda, Y.; Yoshimura, K.; Takahashi, J.; Nakamura, N.; Manome, R.

    2015-12-01

    Understanding plot-scale Cs-137 wash-off is indispensable for predicting Cs-137 fate. However, there are only a few numbers of long-term observations and hence lack of information on temporal trends of Cs-137 wash-off leaves uncertainties on the predictions. This study shows approximately three years' observation results of plot-scale Cs-137 wash-off from various land uses after the accident of Fukushima Dai-ichi Nuclear Power Plant. Erosion plots (22.3 m × 5.0 m) were established in 2011 and 2013 on two uncultivated farmlands (FL-A1, FL-B1), two cultivated farmlands (FL-A2, FL-B2), three grasslands (GL-A, GL-B, GL-C) and one Japanese cedar forest (JCdF) in Kawamata town. Eroded sediments as well as the data of rainfall and vegetation cover were collected almost every two weeks. At the end of observations, we took soil samples from three to nine points on each plot with scraper plates (30 cm ×15 cm) to obtain Cs-137 depth distributions. Collected sediment and soil samples were dried, weighed and measured with HPGe type gamma detectors. We calculated βeff, 'effective' relaxation depth (g/m2), based on Cs-137 depth distributions. Annual soil loss ranged from 0.04 to 75 t/ha/year and the largest was from FL-A2 followed by FL-B2, FL-A1, FL-B1, GL-A, GL-B, JCdF and then GL-C. Sediment amount weighted mean values of Cs-137 concentration normalized by initial deposition density ranged from 0.0062 to 0.084 ((Bq/kg)/(Bq/m2)) and the largest was from JCdF followed by FL-B1, FL-A1, GL-A, FL-A2, FL-B2, GL-B, and then GL-C. Decreasing trends of Cs-137 concentration were found on FL-A1 and FL-B1, whereas no trend was found on other plots due to constant values on FL-A2 and FL-B2 and due to variable values on GL-C, GL-B, GL-C and JCdF. Depth distributions of Cs-137 on FL-A1 and FL-B1 showed exponential distributions with low inventories on their upslope points and deeper penetrations with high inventories on their downslope points. Mean values of βeff ranged from 2.1 to 24

  17. Fatal motorcycle accidents and alcohol

    DEFF Research Database (Denmark)

    Larsen, C F; Hardt-Madsen, M

    1987-01-01

    A series of fatal motorcycle accidents from a 7-year period (1977-1983) has been analyzed. Of the fatalities 30 were operators of the motorcycle, 11 pillion passengers and 8 counterparts. Of 41 operators 37% were sober at the time of accident, 66% had measurable blood alcohol concentration (BAC...

  18. 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

  19. [Practical management of CPB accident].

    Science.gov (United States)

    Depoix, J-P; Fenet, L; Provenchere, S

    2012-05-01

    Accident of CPB is a reality. It is important to be prepared for discussion with the family, with the hospital administration, eventually with the justice. But we have also to support perfusionnist and anesthetic team in charge of the patient during accident.

  20. 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

  1. Unclassified Source Term and Radionuclide Data for Corrective Action Unit 98: Frenchman Flat Nevada Test Site, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    Farnham, Irene

    2005-09-01

    Frenchman Flat is one of several areas of the Nevada Test Site (NTS) used for underground nuclear testing (Figure 1-1). These nuclear tests resulted in groundwater contamination in the vicinity of the underground test areas. As a result, the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) is currently conducting a corrective action investigation (CAI) of the Frenchman Flat underground test areas. Since 1996, the Nevada Division of Environmental Protection (NDEP) has regulated NNSA/NSO corrective actions through the ''Federal Facility Agreement and Consent Order'' ([FFACO], 1996). Appendix VI of the FFACO agreement, ''Corrective Action Strategy'', was revised on December 7, 2000, and describes the processes that will be used to complete corrective actions, including those in the Underground Test Area (UGTA) Project. The individual locations covered by the agreement are known as corrective action sites (CASs), which are grouped into corrective action units (CAUs). The UGTA CASs are grouped geographically into five CAUs: Frenchman Flat, Central Pahute Mesa, Western Pahute Mesa, Yucca Flat/Climax Mine, and Rainier Mesa/Shoshone Mountain (Figure 1-1). These CAUs have distinctly different contaminant source, geologic, and hydrogeologic characteristics related to their location (FFACO, 1996). The Frenchman Flat CAU consists of 10 CASs located in the northern part of Area 5 and the southern part of Area 11 (Figure 1-1). This report documents the evaluation of the information and data available on the unclassified source term and radionuclide contamination for Frenchman Flat, CAU 98. The methodology used to estimate hydrologic source terms (HSTs) for the Frenchman Flat CAU is also documented. The HST of an underground nuclear test is the portion of the total inventory of radionuclides that is released over time into the groundwater following the test. The total residual inventory

  2. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...... of accidents in normally Danish winter seasons are remarkable alike the amount of salt used in praxis in the winter 2011/2012. • 2.7 ton NaCl/km when using brine spread with nozzles • 5 ton NaCl/km when using pre wetted salt. • 5.7 ton NaCl/km when using kombi spreaders The explanation is that spreading...

  3. Corporate Cost of Occupational Accidents

    DEFF Research Database (Denmark)

    Rikhardsson, Pall M.; Impgaard, M.

    2004-01-01

    method could be used in all of the companies without revisions. The evaluation of accident cost showed that 2/3 of the costs of occupational accidents are visible in the Danish corporate accounting systems reviewed while 1/3 is hidden from management view. The highest cost of occupational accidents......The systematic accident cost analysis (SACA) project was carried out during 2001 by The Aarhus School of Business and PricewaterhouseCoopers Denmark with financial support from The Danish National Working Environment Authority. Its focused on developing and testing a method for evaluating...... occupational costs of companies for use by occupational health and safety professionals. The method was tested in nine Danish companies within three different industry sectors and the costs of 27 selected occupational accidents in these companies were calculated. One of the main conclusions is that the SACA...

  4. 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.

  5. An efficient and stable hydrodynamic model with novel source term discretization schemes for overland flow and flood simulations

    Science.gov (United States)

    Xia, Xilin; Liang, Qiuhua; Ming, Xiaodong; Hou, Jingming

    2017-05-01

    Numerical models solving the full 2-D shallow water equations (SWEs) have been increasingly used to simulate overland flows and better understand the transient flow dynamics of flash floods in a catchment. However, there still exist key challenges that have not yet been resolved for the development of fully dynamic overland flow models, related to (1) the difficulty of maintaining numerical stability and accuracy in the limit of disappearing water depth and (2) inaccurate estimation of velocities and discharges on slopes as a result of strong nonlinearity of friction terms. This paper aims to tackle these key research challenges and present a new numerical scheme for accurately and efficiently modeling large-scale transient overland flows over complex terrains. The proposed scheme features a novel surface reconstruction method (SRM) to correctly compute slope source terms and maintain numerical stability at small water depth, and a new implicit discretization method to handle the highly nonlinear friction terms. The resulting shallow water overland flow model is first validated against analytical and experimental test cases and then applied to simulate a hypothetic rainfall event in the 42 km2 Haltwhistle Burn, UK.

  6. Fatal train accidents on Europe's railways: 1980-2009.

    Science.gov (United States)

    Evans, Andrew W

    2011-01-01

    This paper presents an analysis of fatal train accident rates and trends on Europe's main line railways from 1980 to 2009. The paper uses a new set of data for the European Union together with Norway and Switzerland, assembled partly under the auspices of the European Railway Agency and partly on the author's own account. The estimated overall trend in the number of fatal train collisions and derailments per train-kilometre is -6.3% per year from 1990 to 2009, with a 95% confidence interval of -8.7% to -3.9%. The estimated accident rate in 2009 is 1.35 fatal collisions or derailments per billion train-kilometres, giving an estimated mean number of fatal accidents in 2009 of 6.0. The overall number of fatalities per fatal accident in 1990-2009 is 4.10, with no apparent long term change over time, giving an estimated mean of 24.6 fatalities per year in train collisions and derailments in 2009. There are statistically significant differences in the fatal train accident rates and trends between the different European countries, although the estimates of the rates and trends for many individual countries have wide confidence limits. The distribution of broad causes of accidents appears to have remained unchanged over the long term, so that safety improvements appear to have been across the board, and not focused on any specific cause. The most frequent cause of fatal train collisions and derailments is signals passed at danger. In contrast to fatal train collisions and derailments, the rate per train-kilometre of serious accidents at level crossings remained unchanged in 1990-2009. The immediate causes of most of the serious level crossing accidents are errors or violations by road users. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Typologie des Accidents Cyclistes

    OpenAIRE

    Amoros, Emmanuelle; BILLOT-GRASSET, Alice; Hours, Martine

    2015-01-01

    L'usage du vélo est en hausse en ville ; cette pratique est encouragée dans le cadre du développement durable et de la lutte contre la sédentarité. Pour accompagner cela, il faut réduire les risques d'accident, et pour ce faire, mieux les connaître. Nous utilisons le Registre des victimes de la circulation routière du Rhône, basé sur les services hospitaliers (dont les urgences) ; il est quasi-exhaustif : env. 1100 blessés à vélo/an versus 120 dans les données officielles. L'ensemble des cycl...

  8. Analysis of Radionuclide Releases from the Fukushima Dai-ichi Nuclear Power Plant Accident Part II

    Science.gov (United States)

    Achim, Pascal; Monfort, Marguerite; Le Petit, Gilbert; Gross, Philippe; Douysset, Guilhem; Taffary, Thomas; Blanchard, Xavier; Moulin, Christophe

    2014-03-01

    The present part of the publication (Part II) deals with long range dispersion of radionuclides emitted into the atmosphere during the Fukushima Dai-ichi accident that occurred after the March 11, 2011 tsunami. The first part (Part I) is dedicated to the accident features relying on radionuclide detections performed by monitoring stations of the Comprehensive Nuclear Test Ban Treaty Organization network. In this study, the emissions of the three fission products Cs-137, I-131 and Xe-133 are investigated. Regarding Xe-133, the total release is estimated to be of the order of 6 × 1018 Bq emitted during the explosions of units 1, 2 and 3. The total source term estimated gives a fraction of core inventory of about 8 × 1018 Bq at the time of reactors shutdown. This result suggests that at least 80 % of the core inventory has been released into the atmosphere and indicates a broad meltdown of reactor cores. Total atmospheric releases of Cs-137 and I-131 aerosols are estimated to be 1016 and 1017 Bq, respectively. By neglecting gas/particulate conversion phenomena, the total release of I-131 (gas + aerosol) could be estimated to be 4 × 1017 Bq. Atmospheric transport simulations suggest that the main air emissions have occurred during the events of March 14, 2011 (UTC) and that no major release occurred after March 23. The radioactivity emitted into the atmosphere could represent 10 % of the Chernobyl accident releases for I-131 and Cs-137.

  9. Fukushima Daiichi Nuclear Plant accident: Atmospheric and oceanic impacts over the five years.

    Science.gov (United States)

    Hirose, Katsumi

    2016-06-01

    The Fukushima Daiichi Nuclear Plant (FDNPP) accident resulted in huge environmental and socioeconomic impacts to Japan. To document the actual environmental and socioeconomic effects of the FDNPP accident, we describe here atmospheric and marine contamination due to radionuclides released from the FDNPP accident using papers published during past five years, in which temporal and spatial variations of FDNPP-derived radionuclides in air, deposition and seawater and their mapping are recorded by local, regional and global monitoring activities. High radioactivity-contaminated area in land were formed by the dispersion of the radioactive cloud and precipitation, depending on land topography and local meteorological conditions, whereas extremely high concentrations of (131)I and radiocesium in seawater occurred due to direct release of radioactivity-contaminated stagnant water in addition to atmospheric deposition. For both of atmosphere and ocean, numerical model simulations, including local, regional and global-scale modeling, were extensively employed to evaluate source terms of the FDNPP-derived radionuclides from the monitoring data. These models also provided predictions of the dispersion and high deposition areas of the FDNPP-derived radionuclides. However, there are significant differences between the observed and simulated values. Then, the monitoring data would give a good opportunity to improve numerical modeling.

  10. Beyond designed functional margins in CANDU type NPP. Radioactive nuclei assessment in an LOCA type accident

    Directory of Open Access Journals (Sweden)

    Budu Andrei Razvan

    2015-01-01

    Full Text Available European Union's energy roadmap up to year 2050 states that in order to have an efficient and sustainable economy, with minimum or decreasing greenhouse gas emissions, along with use of renewable resources, each constituent state has the option for nuclear energy production as one desirable option. Every scenario considered for tackling climate change issues, along with security of supply positions the nuclear energy as a recommended option, an option that is highly competitive with respect to others. Nuclear energy, along with other renewable power sources are considered to be the main pillars in the energy sector for greenhouse gas emission mitigation at European level. European Union considers that nuclear energy must be treated as a highly recommended option since it can contribute to security of energy supply. Romania showed excellent track-records in operating in a safe and economically sound manner of Cernavoda NPP Units 1&2. Both Units are in top 10 worldwide in terms of capacity factor. Due to Romania's need to ensure the security of electricity supply, to meet the environmental targets and to move to low carbon generation technologies, Cernavoda Units 3&4 Project appears as a must. This Project was started in 2010 and it is expected to have the Units running by 2025. Cost effective and safety operation of a Nuclear Power Plant is made taking into consideration functional limits of its equipment. As common practice, every nuclear reactor type (technology used is tested according to the worse credible accident or equipment failure that can occur. For CANDU type reactor, this is a Loss of Cooling Accident (LOCA. In a LOCA type accident in a CANDU NPP, using RELAP/SCDAP code for fuel bundle damage assessment the radioactive nuclei are to be quantified. Recently, CANDU type NPP accidents are studied using the RELAP/SCDAP code only. The code formerly developed for PWR type reactors was adapted for the CANDU geometry and can assess the

  11. An analysis of accident data for franchised public buses in Hong Kong.

    Science.gov (United States)

    Evans, W A; Courtney, A J

    1985-10-01

    This paper analyses data on accidents involving franchised public buses operating in Hong Kong. The data were obtained from the Royal Hong Kong Police, the Hong Kong Government Transport Department, the two major franchised bus operators and international sources. The analysis includes an international comparison of accidents with emphasis on the situation in Hong Kong compared to urban areas in the United Kingdom. An attempt has been made to identify the characteristics of bus accidents; accident incidence has been related to time of day, day of the week, time of year, weather conditions, driver's age and experience, hours on duty and policy-reported cause. The results indicate that Hong Kong has a high accident rate compared to Japan, the U.K. and the U.S.A., with particularly high pedestrian involvement rates. Bus accidents peak at around 9:00 AM and 4:00 PM but the accident rate is high throughout the day. Monday and Saturday appear to have a higher than average accident rate. The variability of accident rate throughout the year does not seem to be significant and the accident rate does not appear to be influenced by weather conditions. Older, more experienced drivers generally have a safer driving record than their younger, less experienced colleagues. Accident occurrence is related to the time the driver has been on duty. The paper questions the reliability of police-reported accident causation data and suggests improvements in the design of the accident report form and in the training of police investigators. The relevance of the Hong Kong study for accident research in general is also discussed.

  12. 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.

  13. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    Directory of Open Access Journals (Sweden)

    Soo-Yong Park

    2015-10-01

    Full Text Available Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

  14. Sources

    OpenAIRE

    2015-01-01

    SOURCES MANUSCRITES Archives nationales Rôles de taille 1768/71 Z1G-344/18 Aulnay Z1G-343a/02 Gennevilliers Z1G-340/01 Ivry Z1G-340/05 Orly Z1G-334c/09 Saint-Remy-lès-Chevreuse Z1G-344/18 Sevran Z1G-340/05 Thiais 1779/80 Z1G-391a/18 Aulnay Z1G-380/02 Gennevilliers Z1G-385/01 Ivry Z1G-387b/05 Orly Z1G-388a/09 Saint-Remy-lès-Chevreuse Z1G-391a/18 Sevran Z1G-387b/05 Thiais 1788/89 Z1G-451/18 Aulnay Z1G-452/21 Chennevières Z1G-443b/02 Gennevilliers Z1G-440a/01 Ivry Z1G-452/17 Noiseau Z1G-445b/05 ...

  15. An admissibility and asymptotic-preserving scheme for systems of conservation laws with source term on 2D unstructured meshes

    Science.gov (United States)

    Blachère, F.; Turpault, R.

    2016-06-01

    The objective of this work is to design explicit finite volumes schemes for specific systems of conservations laws with stiff source terms, which degenerate into diffusion equations. We propose a general framework to design an asymptotic preserving scheme, that is stable and consistent under a classical hyperbolic CFL condition in both hyperbolic and diffusive regime, for any two-dimensional unstructured mesh. Moreover, the scheme developed also preserves the set of admissible states, which is mandatory to keep physical solutions in stiff configurations. This construction is achieved by using a non-linear scheme as a target scheme for the diffusive equation, which gives the form of the global scheme for the complete system of conservation laws. Numerical results are provided to validate the scheme in both regimes.

  16. Dynamical behaviors of the shock compacton in the nonlinearly Schrödinger equation with a source term

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Jiuli, E-mail: yjl@ujs.edu.cn; Zhao, Liuwei

    2014-11-07

    In this paper, the dynamics from the shock compacton to chaos in the nonlinearly Schrödinger equation with a source term is investigated in detail. The existence of unclosed homoclinic orbits which are not connected with the saddle point indicates that the system has a discontinuous fiber solution which is a shock compacton. We prove that the shock compacton is a weak solution. The Melnikov technique is used to detect the conditions for the occurrence from the shock compacton to chaos and further analysis of the conditions for chaos suppression. The results show that the system turns to chaos easily under external disturbances. The critical parameter values for chaos appearing are obtained analytically and numerically using the Lyapunov exponents and the bifurcation diagrams.

  17. Nuclear power plant Severe Accident Research Plan

    Energy Technology Data Exchange (ETDEWEB)

    Larkins, J T; Cunningham, M A

    1983-01-01

    The Severe Accident Research Plan (SARP) will provide technical information necessary to support regulatory decisions in the severe accident area for existing or planned nuclear power plants, and covers research for the time period of January 1982 through January 1986. SARP will develop generic bases to determine how safe the plants are and where and how their level of safety ought to be improved. The analysis to address these issues will be performed using improved probabilistic risk assessment methodology, as benchmarked to more exact data and analysis. There are thirteen program elements in the plan and the work is phased in two parts, with the first phase being completed in early 1984, at which time an assessment will be made whether or not any major changes will be recommended to the Commission for operating plants to handle severe accidents. Additionally at this time, all of the thirteen program elements in Chapter 5 will be reviewed and assessed in terms of how much additional work is necessary and where major impacts in probabilistic risk assessment might be achieved. Confirmatory research will be carried out in phase II to provide additional assurance on the appropriateness of phase I decisions. Most of this work will be concluded by early 1986.

  18. A study on source term assessment and waste disposal requirement of decontamination and decommissioning for the TRIGA research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Whang, Joo Ho; Lee, Kyung JIn; Lee, Jae Min; Choi, Gyu Seup; Shin, Byoung Sun [Kyunghee Univ., Seoul (Korea, Republic of)

    1999-08-15

    The objective and necessity of the project : TRIGA is the first nuclear facility that decide to decommission and decontamination in our nation. As we estimate the expected life of nuclear power generation at 30 or 40 years, the decommissioning business should be conducted around 2010, and the development of regulatory technique supporting it should be developed previously. From a view of decommissioning and decontamination, the research reactor is just small in scale but it include all decommissioning and decontamination conditions. So, the rules by regulatory authority with decommissioning will be a guide for nuclear power plant in the future. The basis of regulatory technique required when decommissioning the research reactor are the radiological safety security and the data for it. The source term is very important condition not only for security of worker but for evaluating how we dispose the waste is appropriate for conducting the middle store and the procedure after it when the final disposal is considered. The content and the scope in this report contain the procedure of conducting the assessment of the source term which is most important in understanding the general concept of the decommissioning procedure of the decommissioning and decontamination of TRIGA research reactor. That is, the sampling and measuring method is presented as how to measure the volume of the radioactivity of the nuclear facilities. And also, the criterion of classifying the waste occurred in other countries and the site release criteria which is the final step of decommissioning and decontamination presented through MARSSIM. Finally, the program to be applicable through comparing the methods of our nation and other countries ones is presented as plan for disposal of the waste in the decommissioning.

  19. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  20. A Methodology for the Integration of a Mechanistic Source Term Analysis in a Probabilistic Framework for Advanced Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, Dave; Brunett, Acacia J.; Bucknor, Matthew

    2016-06-26

    GE Hitachi Nuclear Energy (GEH) and Argonne National Laboratory are currently engaged in a joint effort to modernize and develop probabilistic risk assessment (PRA) techniques for advanced non-light water reactors. At a high level, the primary outcome of this project will be the development of next-generation PRA methodologies that will enable risk-informed prioritization of safety- and reliability-focused research and development, while also identifying gaps that may be resolved through additional research. A subset of this effort is the development of PRA methodologies to conduct a mechanistic source term (MST) analysis for event sequences that could result in the release of radionuclides. The MST analysis seeks to realistically model and assess the transport, retention, and release of radionuclides from the reactor to the environment. The MST methods developed during this project seek to satisfy the requirements of the Mechanistic Source Term element of the ASME/ANS Non-LWR PRA standard. The MST methodology consists of separate analysis approaches for risk-significant and non-risk significant event sequences that may result in the release of radionuclides from the reactor. For risk-significant event sequences, the methodology focuses on a detailed assessment, using mechanistic models, of radionuclide release from the fuel, transport through and release from the primary system, transport in the containment, and finally release to the environment. The analysis approach for non-risk significant event sequences examines the possibility of large radionuclide releases due to events such as re-criticality or the complete loss of radionuclide barriers. This paper provides details on the MST methodology, including the interface between the MST analysis and other elements of the PRA, and provides a simplified example MST calculation for a sodium fast reactor.

  1. Network of anatomical texts (NAnaTex), an open-source project for visualizing the interaction between anatomical terms.

    Science.gov (United States)

    Momota, Ryusuke; Ohtsuka, Aiji

    2017-07-24

    Anatomy is the science and art of understanding the structure of the body and its components in relation to the functions of the whole-body system. Medicine is based on a deep understanding of anatomy, but quite a few introductory-level learners are overwhelmed by the sheer amount of anatomical terminology that must be understood, so they regard anatomy as a dull and dense subject. To help them learn anatomical terms in a more contextual way, we started a new open-source project, the Network of Anatomical Texts (NAnaTex), which visualizes relationships of body components by integrating text-based anatomical information using Cytoscape, a network visualization software platform. Here, we present a network of bones and muscles produced from literature descriptions. As this network is primarily text-based and does not require any programming knowledge, it is easy to implement new functions or provide extra information by making changes to the original text files. To facilitate collaborations, we deposited the source code files for the network into the GitHub repository ( https://github.com/ryusukemomota/nanatex ) so that anybody can participate in the evolution of the network and use it for their own non-profit purposes. This project should help not only introductory-level learners but also professional medical practitioners, who could use it as a quick reference.

  2. Detecting long-term changes in point-source fossil CO2 emissions with tree ring archives

    Science.gov (United States)

    Keller, Elizabeth D.; Turnbull, Jocelyn C.; Norris, Margaret W.

    2016-05-01

    We examine the utility of tree ring 14C archives for detecting long-term changes in fossil CO2 emissions from a point source. Trees assimilate carbon from the atmosphere during photosynthesis, in the process faithfully recording the average atmospheric 14C content in each new annual tree ring. Using 14C as a proxy for fossil CO2, we examine interannual variability over six years of fossil CO2 observations between 2004-2005 and 2011-2012 from two trees growing near the Kapuni Gas Treatment Plant in rural Taranaki, New Zealand. We quantify the amount of variability that can be attributed to transport and meteorology by simulating constant point-source fossil CO2 emissions over the observation period with the atmospheric transport model WindTrax. We compare model simulation results to observations and calculate the amount of change in emissions that we can detect with new observations over annual or multi-year time periods, given both the measurement uncertainty of 1ppm and the modelled variation in transport. In particular, we ask, what is the minimum amount of change in emissions that we can detect using this method, given a reference period of six years? We find that changes of 42 % or more could be detected in a new sample from one year at the same observation location or 22 % in the case of four years of new samples. This threshold is reduced and the method becomes more practical the more the size of the signal increases. For point sources 10 times larger than the Kapuni plant (a more typical size for power plants worldwide), it would be possible to detect sustained emissions changes on the order of 10 %, given suitable meteorology and observations.

  3. 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.

  4. Development and operation of the network system for nuclear safety - Improvement of the following accident dose assessment system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Enn Han; Han, Moon Hee; Suh, Kyung Suk; Hwang, Won Tae [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    The FADAS has been updates for calculating the real-time wind fields continuously at the nuclear sites in Korea. The system has been constructed to compute the wind fields using its own process for the dummy meteorological data, and does not effect on the overall wind field module. If the radioactive materials are released into the atmosphere in real situation, the calculations of wind fields and exposure dose in the previous FADAS are performed in the case of the recognition of the above situation in the source term evaluation module. The current version of FADAS includes the program for evaluating the effect of the predicted accident and the assumed scenario together. The dose assessment module is separated into the real-time and the supposed accident respectively. 8 refs., 17 figs., 10 tabs. (Author)

  5. [Prevention of bicycle accidents].

    Science.gov (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T

    2015-04-01

    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  6. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    Science.gov (United States)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  7. Traffic accidents involving fatigue driving and their extent of casualties.

    Science.gov (United States)

    Zhang, Guangnan; Yau, Kelvin K W; Zhang, Xun; Li, Yanyan

    2016-02-01

    The rapid progress of motorization has increased the number of traffic-related casualties. Although fatigue driving is a major cause of traffic accidents, the public remains not rather aware of its potential harmfulness. Fatigue driving has been termed as a "silent killer." Thus, a thorough study of traffic accidents and the risk factors associated with fatigue-related casualties is of utmost importance. In this study, we analyze traffic accident data for the period 2006-2010 in Guangdong Province, China. The study data were extracted from the traffic accident database of China's Public Security Department. A logistic regression model is used to assess the effect of driver characteristics, type of vehicles, road conditions, and environmental factors on fatigue-related traffic accident occurrence and severity. On the one hand, male drivers, trucks, driving during midnight to dawn, and morning rush hours are identified as risk factors of fatigue-related crashes but do not necessarily result in severe casualties. Driving at night without street-lights contributes to fatigue-related crashes and severe casualties. On the other hand, while factors such as less experienced drivers, unsafe vehicle status, slippery roads, driving at night with street-lights, and weekends do not have significant effect on fatigue-related crashes, yet accidents associated with these factors are likely to have severe casualties. The empirical results of the present study have important policy implications on the reduction of fatigue-related crashes as well as their severity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Longitudinal relationship between economic development and occupational accidents in China.

    Science.gov (United States)

    Song, Li; He, Xueqiu; Li, Chengwu

    2011-01-01

    The relativity between economic development and occupational accidents is a debated topic. Compared with the development courses of both economic development and occupational accidents in China during 1953-2008, this paper used statistic methods such as Granger causality test, cointegration test and impulse response function based on the vector autoregression model to investigate the relativity between economic development and occupational accidents in China from 1953 to 2008. Owing to fluctuation and growth scale characteristics of economic development, two dimensions including economic cycle and economic scale were divided. Results showed that there was no relationship between occupational accidents and economic scale during 1953-1978. Fatality rate per 10(5) workers was a conductive variable to gross domestic product per capita during 1979-2008. And economic cycle was an indicator to occupational accidents during 1979-2008. Variation of economic speed had important influence on occupational accidents in short term. Thus it is necessary to adjust Chinese occupational safety policy according to tempo variation of economic growth.

  9. Thermal balance in term and preterm newborn infants nursed in an incubator equipped with a radiant heat source.

    Science.gov (United States)

    Sjörs, G; Hammarlund, K; Sedin, G

    1997-04-01

    A radiant hood warmer, a device that heats the incubator roof independently of the incubator's main heat source, was used to study the thermal balance of 11 full term and 13 preterm (gestational age 25-34 weeks) infants exposed to an isolated elevation of incubator roof temperature at stable ambient air temperature and humidity. After initial measurements without active heating of the incubator roof, the hood warmer was set to 33 degrees C, 36 degrees C and finally (preterm infants only) to 39 degrees C. At least 18 min of measurements with the infant asleep were made at each hood warmer setting. In the term infants an increase in roof temperature from 30.5 degrees C to 35.6 degrees C resulted in an increase in skin temperature from 35.4 to 35.9 degrees C, and a decrease in radiative heat loss from 32.8 to 20.7 W/m2 exposed skin. In the preterm infants an increase in roof temperature from 31.0 to 38.4 degrees C led to an increase in skin temperature from 35.7 to 36.3 degrees C and a decrease in radiative heat loss from 34.1 to 13.0 W/m2 exposed skin. The increased inner roof surface temperature did not affect evaporative or convective heat loss, skin blood flow, respiratory water loss, oxygen consumption or transepidermal water loss in either group. Thus, at stable ambient air temperature and humidity, the increase in incubator roof temperature resulted in an increase in skin temperature and a decrease in radiative heat loss in both term and preterm infants.

  10. Three Mile Island Accident Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Three Mile Island Accident Data consists of mostly upper air and wind observations immediately following the nuclear meltdown occurring on March 28, 1979, near...

  11. Paragliding accidents in remote areas.

    Science.gov (United States)

    Fasching, G; Schippinger, G; Pretscher, R

    1997-08-01

    Paragliding is an increasingly popular hobby, as people try to find new and more adventurous activities. However, there is an increased and inherent danger with this sport. For this reason, as well as the inexperience of many operators, injuries occur frequently. This retrospective study centers on the helicopter rescue of 70 individuals in paragliding accidents. All histories were examined, and 43 patients answered a questionnaire. Nineteen (42%) pilots were injured when taking off, 20 (44%) during the flight, and six (13%) when landing. Routine and experience did not affect the prevalence of accident. Analysis of the causes of accident revealed pilot errors in all but three cases. In 34 rescue operations a landing of the helicopter near the site of the accident was possible. Half of the patients had to be rescued by a cable winch or a long rope fixed to the helicopter. Seven (10%) of the pilots suffered multiple trauma, 38 (54%) had injuries of the lower extremities, and 32 (84%) of them sustained fractures. Injuries to the spine were diagnosed in 34 cases with a fracture rate of 85%. One patient had an incomplete paraplegia. Injuries to the head occurred in 17 patients. No paraglider pilot died. The average hospitalization was 22 days, and average time of working inability was 14 weeks. Fourteen (34%) patients suffered from a permanent damage to their nerves or joints. Forty-three percent of the paragliders continued their sport despite the accident; two of them had another accident. An improved training program is necessary to lower the incidence of paragliding accidents. Optimal equipment to reduce injuries in case of accidents is mandatory. The helicopter emergency physician must perform a careful examination, provide stabilization of airways and circulation, give analgesics, splint fractured extremities, and transport the victim on a vacuum mattress to the appropriate hospital.

  12. The Family Policy Implications of a New Social Program: The New Zealand Accident Compensation Scheme.

    Science.gov (United States)

    Vosburgh, Miriam G.; Kronick, Jane C.

    1980-01-01

    Innovations in the New Zealand Accident Compensation Scheme include defining the family unit in terms of past economic support and adapting common law principles to social provision. Accidents are considered a community responsibility. Family implications of this program are discussed. (Author/BEF)

  13. The special severity of occupational accidents in the afternoon: "the lunch effect".

    Science.gov (United States)

    Camino López, Miguel A; Fontaneda, Ignacio; González Alcántara, Oscar J; Ritzel, Dale O

    2011-05-01

    The severity of occupational accidents suffered by construction workers at different hours of the day is analyzed in this study. It may be seen that the interval of time between 13:00 and 17:00 has incomprehensibly high rates of severe and fatal accidents in comparison with any other. We associate this higher accident rate with what we have termed the "lunch effect". We studied 10,239,303 labor accidents in Spain over the period 1990-2002. The relationships between potential risk factors for occupational accidents around lunch in Spain, especially alcohol consumption are studied, using two methods: analysis of national archival data of 2,155,954 occupational accidents suffered by workers in the construction sector over the period 1990-2002 and a survey study. This study also seeks to contribute the opinions of the workers themselves regarding the causes that might explain this situation.

  14. Severe accident analysis using dynamic accident progression event trees

    Science.gov (United States)

    Hakobyan, Aram P.

    In present, the development and analysis of Accident Progression Event Trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. One of the principal deficiencies lies in the static nature of conventional APETs. In the conventional event tree techniques, the sequence of events is pre-determined in a fixed order based on the expert judgments. The main objective of this PhD dissertation was to develop a software tool (ADAPT) for automated APET generation using the concept of dynamic event trees. As implied by the name, in dynamic event trees the order and timing of events are determined by the progression of the accident. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. The function of a dynamic APET developed includes prediction of the conditions, timing, and location of containment failure or bypass leading to the release of radioactive material, and calculation of probabilities of those failures. Thus, scenarios that can potentially lead to early containment failure or bypass, such as through accident induced failure of steam generator tubes, are of particular interest. Also, the work is focused on treatment of uncertainties in severe accident phenomena such as creep rupture of major RCS components, hydrogen burn, containment failure, timing of power recovery, etc. Although the ADAPT methodology (Analysis of Dynamic Accident Progression Trees) could be applied to any severe accident analysis code, in this dissertation the approach is demonstrated by applying it to the MELCOR code [1]. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a

  15. The credibility of a source influences the rate of unconscious plagiarism.

    Science.gov (United States)

    Bink, M L; Marsh, R L; Hicks, J L; Howard, J D

    1999-05-01

    Three experiments were conducted to investigate the relationship between the credibility of information and later unconscious plagiarism of that information. In each experiment, ideas concerning ways to reduce traffic accidents were presented from a more credible source (traffic planners) and a less credible source (college freshmen). After a distractor task, participants were asked to generate novel ways to reduce traffic accidents. In Experiments 1 and 2, unconscious plagiarism of ideas presented from the more credible source was greater than from the less credible source. In neither experiment was explicit memory for ideas from each source different in tests of source monitoring or free recall. However, the difference in unconscious plagiarism was eliminated in Experiment 3 by having participants generate the implications of ideas at study. The results are discussed in terms of the explicit factors that affect the incidence of unconscious plagiarism.

  16. Accident tolerant fuel analysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis [Idaho National Laboratory; Chichester, Heather [Idaho National Laboratory; Johns, Jesse [Texas A& M University; Teague, Melissa [Idaho National Laboratory; Tonks, Michael Idaho National Laboratory; Youngblood, Robert [Idaho National Laboratory

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced ''RISMC toolkit'' that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional ''accident-tolerant'' (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant

  17. [Accidents of fulguration].

    Science.gov (United States)

    Virenque, C; Laguerre, J

    1976-01-01

    Fulguration, first electric accident in which the man was a victim, is to day better known. A clap of thunder is decomposed in two elements: lightning, and thunder. Lightning is caused by an electrical discharge, either within a cloud, or between two clouds, or, above all, between a cloud and the surface of the ground. Experimental equipments owned by the French Electricity Company and by the Atomic Energy Commission, have allowed to photograph lightnings and to measure certain physical characteristics (Intensity variable between 25 to 100 kA, voltage variable between 20 to 1 000 kV). The frequency of storms was learned: the isokeraunic level, in France, is about 20, meaning that thunder is heard twenty days during one year. Man may be stricken by thunder by direct hit, by sudden bursting, by earth current, or through various conductors. The electric charge which reached him may go to the earth directly by contact with the ground or may dissipate in the air through a bony promontory (elbow). The total number of victims, "wounded" or deceased, is not now known by statistics. Death comes by insulation breakdown of one of several anatomic cephalic formations: skull, meninx, brain. Many various lesions may happen in survivors: loss of consciousness, more or less long, sensorial or motion deficiencies. All these signs are momentary and generally reversible. Besides one may observe much more intense lesions on the skin: burns and, over all, characteristic aborescence (skin effect by high frequency current). The heart is protected, contrarily to what happens with industrial electrocution. The curative treatment is merely symptomatic : reanimation, surgery for burns or associated traumatic lesions. A prevention is researched to help the lonely man, in the country or in the mountains in the houses (lightning conductor, Faraday cage), in vehicles (aircraft, cars, ships). The mysterious and unforseeable character of lightning still stays, leaving a door opened for numerous

  18. Accident Tolerant Fuel Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Curtis Smith; Heather Chichester; Jesse Johns; Melissa Teague; Michael Tonks; Robert Youngblood

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced “RISMC toolkit” that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional “accident-tolerant” (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant decision makers should propose and

  19. The Importance of Safety in Construction Sector: Costs of Occupational Accidents in Construction Sites

    Directory of Open Access Journals (Sweden)

    Fatih Yılmaz

    2015-04-01

    Full Text Available Occupational accidents cause important social and economic problems by loss of life and physical injuries. Construction sector involves high risk due to its production processes and labor intensive characteristic and because of occupational accidents the sector brings up against financial loss in large scale. In developing countries, construction sector is one of the most important sectors that have a great contribution to economic development with its employment capacity and added-value to the economy. On the other hand, due to the lack of preventive measures, occupational accidents occur, frequently in construction in Turkey. Major occupational accidents are defined as the cause of serious injuries and a long-term disability; minor occupational accidents are defined as the cause of insignificant injuries and short-term disability. Minor occupational accidents are not considered sufficiently, they are even not kept as a record. It is known that minor occupational accidents, which are not considered sufficiently and even not registered, cause great financial loss in workplaces. The aim of this paper is to investigate the cost of workforce loss caused by the accidents in construction sites by using the statistics of three construction sites in Turkey and to compare the financial losses of minor and major occupational accidents. In this study, three construction project are investigated in Turkey in 2009 and it is obtained that the cost of workday loss caused by major occupational accidents is 19431.75 $ and minor occupational accidents cause a loss of 6924.25 $. The cost of workday loss caused by minor occupational accidents are almost 35 % of major workday losses’. These costs presents the importance of preventive measures for workers’ health and safety in construction.

  20. Measuring Risk Aversion for Nuclear Power Plant Accident: Results of Contingent Valuation Survey in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    external cost of NPP accident, the proposed framework can analytically quantify the risk aversion coefficient, as well as, estimate the accident risk response cost. This study is expected to give insight on external cost estimation of both NPP and other severe accident cases of various energy sectors, especially in terms of accident risk response cost.