WorldWideScience

Sample records for circulating beam accidents

  1. First circulating beam in the AA

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.56 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are too numerous to name them all, but the 3 most prominent ones are at the centre (left to right): Roy Billinge (Joint AA Project Leader, with his hand on the control box), Eifionydd Jones (white shirt), Simon van der Meer (spiritus rector and Joint AA Project Leader). The first antiprotons were injected, made to circulate and cooled soon after, on 14 July 1980.

  2. First circulating beam in the AA

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.5 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are to numerous to name them all. Heribert Koziol, apparently asleep, is answering the call from an impatient director. See also 8007094.

  3. Natural circulation under severe accident conditions

    International Nuclear Information System (INIS)

    Pafford, D.J.; Hanson, D.J.; Tung, V.X.; Chmielewski, S.V.

    1992-01-01

    Research is being conducted to better understand natural circulation phenomena in mixtures of steam and noncondensibles and its influence on the temperature of the vessel internals and the hot leg, pressurizer surge line, and steam generator tubes. The temperature of these structures is important because their failure prior to reactor vessel lower head failure could reduce the likelihood of containment failure as a result of direct containment heating. Computer code calculations (MELPROG, SCDAP/RELAP5/MOD3) predict high fluid temperatures in the upper plenum resulting from in-vessel natural circulation. Using a simple model for the guide tube phenomena, high upper plenum temperatures are shown to be consistent with the relatively low temperatures that were deduced metallurgically from leadscrews removed from the TMI-2 upper plenum. Evaluation of the capabilities of the RELAP5/MOD3 computer code to predict natural circulation behavior was also performed. The code was used to model the Westinghouse natural circulation experimental facility. Comparisons between code calculations and results from experiments show good agreement

  4. Natural-circulation-cooling characteristics during PWR accident simulations

    International Nuclear Information System (INIS)

    Adams, J.P.; McCreery, G.E.; Berta, V.T.

    1983-01-01

    A description of natural circulation cooling characteristics is presented. Data were obtained from several pressurized water reactor accident simulations in the Loss-of-Fluid Test (LOFT) pressurized water reactor (PWR). The reliability of natural circulation cooling, its cooling effectiveness, and the effect of changing system conditions are described. Quantitative comparison of flow rates and time constants with theory for both single- and two-phase fluid conditions were made. It is concluded that natural circulation cooling can be relied on in plant recovery procedures in the absence of forced convection whenever the steam generator heat sink is available

  5. Analysis of hot leg natural circulation under station blackout severe accident

    International Nuclear Information System (INIS)

    Deng Jian; Cao Xuewu

    2007-01-01

    Under severe accidents, natural circulation flows are important to influence the accident progression and result in a pressurized water reactor (PWR). In a station blackout accident with no recovery of steam generator (SG) auxiliary feedwater (TMLB' severe accident scenario), the hot leg countercurrent natural circulation flow is analyzed by using a severe-accident code, to better understand its potential impacts on the creep-rupture timing among the surge line, the hot leg; and SG tubes. The results show that the natural circulation may delay the failure time of the hot leg. The recirculation ratio and the hot mixing factor are also calculated and discussed. (authors)

  6. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    OpenAIRE

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives The aim of this study was to create an extracorporeal circulation system (herein...

  7. Collider and Detector Protection at Beam Accidents

    Science.gov (United States)

    Rakhno, I. L.; Mokhov, N. V.; Drozhdin, A. I.

    2003-12-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occured at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

  8. Collider and Detector Protection at Beam Accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  9. Collider and detector protection at beam accidents

    International Nuclear Information System (INIS)

    Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

    2003-01-01

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

  10. Analysis of SBO accident and natural circulation of 49-2 swimming pool reactor

    International Nuclear Information System (INIS)

    Wu Yuanyuan; Liu Tiancai; Sun Wei

    2012-01-01

    The transient thermal hydraulic characteristics of 49-2 Swimming Pool Reactor (SPR) were analyzed by RELAP5/MOD3.3 code to verify the capability of natural circulation and minus reactivity feedback for accident mitigation under the condition of station blackout (SBO). Then, the effects on accident consequence and sequence for core channels and primary pumps were briefly discussed. The calculation results show that the reactor can be shutdown by the effect of minus reactivity feedback, and the residual heat can be removed through the stable natural circulation. Therefore, it demonstrates that the 49-2 SPR is safe during the accident of SBO. (authors)

  11. Fast betatron tune controller for circulating beam in a synchrotron

    International Nuclear Information System (INIS)

    Endo, Takuyuki; Hatanaka, Kichiji; Sato, Kenji

    1997-01-01

    When rf quadrupole (RFQ) electric field is applied to the circulating beam in a synchrotron, an equation of motion is reduced to Mathieu's Equation. A new analytical method to obtain an approximate solution has been developed, while a numerical computation was usually applied. Translating the behavior of approximate solution into terms of an RFQ electric field and betatron oscillation, a fast tune control can be achieved by rapid tuning of both amplitude and frequency of rf voltage. This process could be applied to suppress a tune shift caused by a space charge effect and to control a slow beam extraction with a low ripple. We have started another analytical computation using Hamiltonian with perturbation of RFQ and the results of this computation also suggest that it is applicable to slow beam extraction. The fast tune controller has been constructed and the beam test will be performed at HIMAC synchrotron in cooperation of RCNP and NIRS. (author)

  12. Evaluation of High-Pressure RCS Natural Circulations Under Severe Accident Conditions

    International Nuclear Information System (INIS)

    Lee, Byung Chul; Bang, Young Suk; Suh, Nam Duk

    2006-01-01

    Since TMI-2 accident, the occurrence of severe accident natural circulations inside RCS during entire in-vessel core melt progressions before the reactor vessel breach had been emphasized and tried to clarify its thermal-hydraulic characteristics. As one of consolidated outcomes of these efforts, sophisticated models have been presented to explain the effects of a variety of engineering and phenomenological factors involved during severe accident mitigation on the integrity of RCS pressure boundaries, i.e. reactor pressure vessel(RPV), RCS coolant pipe and steam generator tubes. In general, natural circulation occurs due to density differences, which for single phase flow, is typically generated by temperature differences. Three natural circulation flows can be formed during severe accidents: in-vessel, hot leg countercurrent flow and flow through the coolant loops. Each of these flows may be present during high-pressure transients such as station blackout (SBO) and total loss of feedwater (TLOFW). As a part of research works in order to contribute on the completeness of severe accident management guidance (SAMG) in domestic plants by quantitatively assessing the RCS natural circulations on its integrity, this study presents basic approach for this work and some preliminary results of these efforts with development of appropriately detailed RCS model using MELCOR computer code

  13. Experiments on natural circulation during PWR severe accidents and their analysis

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Stewart, W.A.; Sha, W.T.

    1988-01-01

    Buoyancy-induced natural circulation flows will occur during the early-part of PWR high pressure accident scenarios. These flows affect several key parameters; in particular, the course of such accidents will most probably change due to local failures occurring in the primary coolant system (CS) before substantial core degradation. Natural circulation flow patterns were measured in a one-seventh scale PWR PCS facility at Westinghouse RandD laboratories. The measured flow and temperature distributions are report in this paper. The experiments were analyzed with the COMMIX code and good agreement was obtained between data and calculations. 10 refs., 8 figs., 2 tabs

  14. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    Science.gov (United States)

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background: Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives: The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. Materials and Methods: In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. Results: The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Conclusions: Thus, we can conclude that a simulator system using an extracorporeal

  15. 10 September: the LHC’s first circulating beam

    CERN Multimedia

    On 10 September, a first beam of protons will circulate in the LHC. The first moments in the life of the LHC will be an exciting time for the CERN staff, and will be captured by more than 250 media organizations from all over the world. The first injection of the beam into the machine will be between 9:00 and 10:00 a. m. At 9:15 the LHC project leader, Lyn Evans, will give a brief explanation of the day’s proceedings in French followed by some words from Robert Aymar, CERN Director general. CERN personnel are invited to follow the first beam day events, which will be shown in the following rooms around CERN: All day: Council Chamber, Main Auditorium, IT Auditorium, AB Auditorium Prévessin, Conference Room 40-S2-A01, Conference Room 40-S2-C01. Afternoon: AB Auditorium Meyrin, AT Auditorium. Please note that the event will also be webcast but, given the limited number of connections, this option is intended for use of the public outside CERN. CERN personnel are encouraged to follow the event from the confe...

  16. Natural Circulation Level Optimization and the Effect during ULOF Accident in the SPINNOR Reactors

    International Nuclear Information System (INIS)

    Abdullah, Ade Gafar; Su'ud, Zaki; Kurniadi, Rizal; Kurniasih, Neny; Yulianti, Yanti

    2010-01-01

    Natural circulation level optimization and the effect during loss of flow accident in the 250 MWt MOX fuelled small Pb-Bi Cooled non-refueling nuclear reactors (SPINNOR) have been performed. The simulation was performed using FI-ITB safety code which has been developed in ITB. The simulation begins with steady state calculation of neutron flux, power distribution and temperature distribution across the core, hot pool and cool pool, and also steam generator. When the accident is started due to the loss of pumping power the power distribution and the temperature distribution of core, hot pool and cool pool, and steam generator change. Then the feedback reactivity calculation is conducted, followed by kinetic calculation. The process is repeated until the optimum power distribution is achieved. The results show that the SPINNOR reactor has inherent safety capability against this accident.

  17. Effect of marine condition on feature of natural circulation after accident in floating nuclear power plant

    International Nuclear Information System (INIS)

    Yang Fan; Zhang Dan; Tan Changlu; Ran Xu; Yu Hongxing

    2015-01-01

    The incline and swing effect on natural circulation of floating nuclear power plant under site black out (SBO) accident is studied using self-developing marine condition system code RELAP5/MC. It shows that, for floating nuclear power plant under marine condition, the pressurizer fluctuating flow rate, the parallel heat sink (steam generator) have significant influences on the direct passive reactor heat removal (PRHR) system, which is different from other secondary PRHR under marine condition. The flow exchange between the loop and the pressurizer have major effect on cooling capacity for the left side loop. (authors)

  18. Correlation of Steam Generator Mixing Parameters for Severe Accident Hot-Leg Natural Circulation

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Yehong; Guentay, Salih [Paul Scherrer Institut, Villigen PSI, CH-5232 (Switzerland)

    2008-07-01

    Steam generator inlet plenum mixing phenomenon with hot-leg counter-current natural circulation during a PWR station blackout severe accident is one of the important processes governing which component will fail first as a result of thermal challenge from the circulating gas with high temperature and pressure. Since steam generator tube failure represents bypass release of fission product from the reactor to environment, study of inlet plenum mixing parameters is important to risk analysis. Probability distribution functions of individual mixing parameter should be obtained from experiments or calculated by analysis. In order to perform sensitivity studies of the synergetic effects of all mixing parameters on the severe accident-induced steam generator tube failure, the distribution and correlation of these mixing parameters must be known to remove undue conservatism in thermal-hydraulic calculations. This paper discusses physical laws governing three mixing parameters in a steady state and setups the correlation among these mixing parameters. The correlation is then applied to obtain the distribution of one of the mixing parameters that has not been given in the previous CFD analysis. Using the distributions and considering the inter-dependence of the three mixing parameters, three sensitivity cases enveloping the mixing parameter uncertainties are recommended for the plant analysis. (authors)

  19. Flow and separation in gas centrifuge with Beams type circulation

    International Nuclear Information System (INIS)

    Ajsen, Eh.M.; Borisevich, V.D.; Levin, E.V.

    1992-01-01

    Structure of the secondary circulation flows in the working chamber of gas centrifuge for uranium isotope separation is studied using the numerical methods. Influence of the circulation thermal component on the centrifuge efficiency is analyzed. The contribution of useful component concentration difference of binary isotope mixture in feeding flows to the centrifuge efficiency is determined. Dependence of concentration optimal difference, whereby the maximum efficiency is achieved, on temperature distribution on the rotor side wall is found

  20. Transverse energy circulation and the edge diffraction of an optical vortex beam.

    Science.gov (United States)

    Bekshaev, Aleksandr Ya; Mohammed, Kadhim A; Kurka, Ivan A

    2014-04-01

    Edge diffraction of a circular Laguerre-Gaussian beam represents an example of the optical vortex symmetry breakdown in which the hidden "vortex" energy circulation is partially transformed into the visible "asymmetry" form. The diffracted beam evolution is studied in terms of the irradiance moments and the moment-based parameters. In spite of the limited applicability of the moment-based formalism, we show that the "vortex" and "asymmetry" parts of the orbital angular momentum can still be reasonably defined for the hard-edge diffracted beams and retain their physical role of quantifying the corresponding forms of the transverse energy circulation.

  1. Multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers.

    Science.gov (United States)

    Chen, Jing-Heng; Chen, Kun-Huang; Lin, Jiun-You; Hsieh, Hsiang-Yung

    2010-03-10

    Optical circulators are necessary passive devices applied in optical communication systems. In the design of optical circulators, the implementation of the function of spatial walk-off polarizers is a key technique that significantly influences the performance and cost of a device. This paper proposes a design of a multiport optical circulator by using polarizing beam splitter cubes as spatial walk-off polarizers. To show the feasibility of the design, a prototype of a six-port optical circulator was fabricated. The insertion losses are 0.94-1.49 dB, the isolations are 25-51 dB, and return losses are 27.72 dB.

  2. Analysis of an accident with the main circulation tube rupture at the WWER-1000

    International Nuclear Information System (INIS)

    Boyadzhiev, A.I.; Stefanova, S.J.

    1984-01-01

    In connection with the forthcoming construction of a npp with the wwer-1000 reactor the loss of coolant accident associated with the main circulation tube rupture at the inlet near the reactor is analyzed. The relap4/mod6 program is used for the analysis. The data obtained show that the coolant outflow stage continues for about 25s. On the average the pressure in the circuits varies from 16 to 10 mpa per 0.1s and then it continues to decrease slowly. The pressure in the steam generator at the secondary circuits end increases approximately up to 6.9 MPa as a result of steam generator blocking and remaining coolant heating and then somewhat decreases owing to the primary circuit cooling. By the end of the fuel and can temperatures are equalized and the heat transfer coefficient is stabilized at the level of 100 w/1 (m 2 xK). It is concluded that during a loss of coolant accident at the wwer-1000 reactor in procesess of coolant blowdown in the medium power fuel elemets neither the fuel, melting temperature (3000 k), nor the critical temperature (1000 k) of plastic deformation zirconiu can initiation are attained

  3. Analysis of a Natural Circulation in the Reactor Coolant System Following a High Pressure Severe Accident at APR1400

    International Nuclear Information System (INIS)

    Kim, Han Chul; Cho, Yong Jin; Park, Jae Hong; Cho, Song Won

    2011-01-01

    Under a high temperature and pressure condition during a severe accident, hot leg pipes or steam generator tubes could fail due to creep rupture following natural circulation in the Reactor Coolant System (RCS) unless depressurization of the system is performed at a proper time. Natural circulation in the RCS can be a multi-dimensional circulation in the reactor vessel, a partial loop circulation of two-phase flow from the core up to steam generators (SGs), or circulation in the total loop. It can delay the reactor vessel failure time by removing heat from the reactor core. This natural phenomenon can be hardly simulated with a single flow path model for the hot spots of the RCS, since it cannot deal with the counter-current flow. Thus it may estimate accident progression faster than reality, which may cause troubles for optimized implementation of severe accident management strategies. An earlier damage in the RCS other than the reactor pressure vessel may make subsequent behaviors of hydrogen or fission products in the containment quite different from the single reactor vessel failure. Therefore, a RCS model which treats natural circulation is needed to evaluate the RCS response and the safety depressurization strategy in a best-estimate way. The aim of this study is to develop a detailed model which allows natural circulation between the reactor vessel and steam generators through hot legs, based on the existing APR1400 RCS model. The station blackout sequence was selected to be the representative high-pressure scenario. Sensitivity study on the effect of node configuration of the upper plenum and addition of cross flow paths from the upper plenum to the hot legs were carried out. This model is described herein and representative calculation results are presented

  4. In-vessel natural circulation during a hypothetical loss-of-heat-sink accident in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Perkins, K.R.; Bari, R.A.; Pratt, W.T.

    1979-05-01

    The capability to remove decay heat from the FFTF core via in-vessel natural circulation has been analyzed for the preboiling phase using a lumped parameter model. The results indicate that boiling will occur in the average fuel assembly for a wide spectrum of initial conditions which appear to be representative of the hypothetical loss-of-heat-sink accident. Two-phase pressure drop calculations indicate that, once the saturation temperature is reached, coolability can only be assured for decay heat levels which are less than 0.5% of the operating power. A review of the limited sodium boiling data indicates that boiling-induced natural circulation may support up to 4% of the operating power, but geometric atypicalities and a large degree of inlet subcooling for the existing data limit the applicability to the loss-of-heat-sink accident in FFTF

  5. Deformation and Heat Transfer on Three Sides Protected Beams under Fire Accident

    Science.gov (United States)

    Imran, M.; Liew, M. S.; Garcia, E. M.; Nasif, M. S.; Yassin, A. Y. M.; Niazi, U. M.

    2018-04-01

    Fire accidents are common in oil and gas industry. The application of passive fire protection (PFP) is a costly solution. The PFP is applied only on critical structural members to optimise project cost. In some cases, beams cannot be protected from the top flange in order to accommodate for the placement of pipe supports and grating. It is important to understand the thermal and mechanical response of beam under such condition. This paper discusses the response of steel beam under ISO 834 fire protected, unprotected and three sides protected beams. The model validated against an experimental study. The experimental study has shown good agreement with FE model. The study revealed that the beams protected from three sides heat-up faster compare to fully protected beam showing different temperature gradient. However, the affects load carrying capacity are insignificant under ISO 834 fire.

  6. Review of common accidents in external beam radiotherapy

    International Nuclear Information System (INIS)

    Ombogo, C.M

    2015-02-01

    This work covers patients protection in Radiotherapy which is a multi step procedure that is complex. Any error in any step has an effect on the patient and therefore the entire process requires attention to details in order to achieve patients protection. This project reviews eight case studies involving accidents that occurred during the process of therapy delivery. Professionalism in case one and two was not practiced in that in case one medical physicist failed to calculate decay data instead relied on incorrect decay graph thus giving wrong dose. While in case two a wrong TPS was approved following a formal written procedure due to new technology. In case three and seven there was a software malfunction due to uniformed choice of TPS and in case four a computer file was not updated in the TPS while in eight the failure is inter look system led to patients recieving high dose than was prescribed. Calibration in case five and six was due to wrong actions in both repairs and interpretation of treatment time than the overdose to patient. The lessen learnt seeks to act as a checklist for ensuring patient protection in radiotherapy and prevention of future accidents. (au)

  7. Natural circulation cooling in a PWR geometry under accident-induced conditions

    International Nuclear Information System (INIS)

    Shimeck, D.J.; Johnsen, G.W.

    1983-01-01

    The characteristics and limits of natural circulation heat rejection over a wide range of conditions were experimentally investigated in a small-scale model of a pressurized water reactor. Conditions that were varied included primary and secondary coolant inventory, decay heat power, and primary noncondensable gas content. The results have defined three distinct modes of natural circulation, their limits and transition points, and the characteristic signatures accompanying natural circulation behavior. Particular emphasis is focused on the limits of natural circulation under severely degraded primary and secondary conditions

  8. Very Fast Losses of the Circulating LHC Beam, their Mitigation and Machine Protection

    CERN Document Server

    Baer, Tobias; Elsen, Eckhard

    The Large Hadron Collider (LHC) has a nominal energy of 362MJ stored in each of its two counter-rotating beams - over two orders of magnitude more than any previous accelerator and enough to melt 880kg of copper. Therefore, in case of abnormal conditions comprehensive machine protection systems extract the beams safely from the LHC within not more than three turns $\\approx$270$\\mu$s. The first years of LHC operation demonstrated a remarkable reliability of the major machine protection systems. However, they also showed that the LHC is vulnerable to losses of the circulating beams on very fast timescales, which are too fast to ensure an active protection. Very fast equipment failures, in particular of normal-conducting dipole magnets and the transverse damper can lead to such beam losses. Whereas these failures were already studied in the past, other unexpected beam loss mechanisms were observed after the LHC start-up: so-called (un)identified falling objects (UFOs), which are believed to be micrometer-sized m...

  9. Accidental beam loss in superconducting accelerators: Simulations, consequences of accidents and protective measures

    International Nuclear Information System (INIS)

    Drozhdin, A.; Mokhov, N.; Parker, B.

    1994-02-01

    The consequences of an accidental beam loss in superconducting accelerators and colliders of the next generation range from the mundane to rather dramatic, i.e., from superconducting magnet quench, to overheating of critical components, to a total destruction of some units via explosion. Specific measures are required to minimize and eliminate such events as much as practical. In this paper we study such accidents taking the Superconducting Supercollider complex as an example. Particle tracking, beam loss and energy deposition calculations were done using the realistic machine simulation with the Monte-Carlo codes MARS 12 and STRUCT. Protective measures for minimizing the damaging effects of prefire and misfire of injection and extraction kicker magnets are proposed here

  10. \\title{MARS15 Simulation Studies in the CMS Detector of Some LHC Beam Accident Scenarios}

    CERN Document Server

    Bhat, Pushpalatha C; Striganov, S.I; Singh, Amandeep

    2009-01-01

    \\begin{abstract} The CMS tracker, made of silicon strips and pixels and silicon-based electronics, is vulnerable to effects of radiation exposure during the LHC operation. Of much concern is the potential for damage from a high instantaneous dose to the pixel detectors and electronics located only a few centimeters from the beam in the event of a fast accidental beam loss. One of the worst case scenarios for such a beam loss is an unintended firing of an abort kicker module, referred to as the kicker pre-fire. MARS15 simulation studies of radiation loads in CMS for the kicker pre-fire scenario are described in this paper. It is found that, in a kicker pre-fire accident, in a time span of about 100 ns, the innermost pixel layer may see a radiation dose of about 0.02 Gy \\-- equivalent to a fluence of $\\sim 6\\times 10^{7}$ MIPs/$cm^2$. No discernible damage to the pixel detectors or the electronics were seen at these levels of fluence in recent beam tests. We note that the dose is about 1000 times smaller t...

  11. Performance behavior of the passive containment cooling system of a natural circulation BWR during postulated accident condition

    International Nuclear Information System (INIS)

    Kumar, Mukesh; Nayak, A.K.; Jain, Vikas; Vijayan, P.K.; Saha, D.; Sinha, R.K.

    2011-01-01

    Passive systems are playing prominent role in the development of innovative nuclear reactor systems due to their simplicity, enhanced safety, reliability and economy. These systems are being considered for normal operation as well as accidental conditions of reactor following a postulated accident scenario to preclude the scenarios arising out of failure of active systems as well as to minimize the operator intervention. Indian innovative reactor AHWR being designed for thorium utilization employs various passive safety concepts. As containment is the ultimate barrier to the release of radioactivity, passive concepts are being employed in BWRs for minimize peak containment pressure in the containment during a postulated accident condition like LOCA. The concept of passive containment cooling system (PCCS) in the AHWR comprises of inclined tube heat exchangers located underneath an elevated pool that removes the heat from the steam-air atmosphere of containment following a LOCA by natural circulation of water inside the tubes. The steam condenses on the external surface of tubes of PCCS in addition to the wall of the containment which in turn depressurizes the containment. This paper deals with the performance assessment of PCCS of AHWR during a postulated design basis LOCA by using the best estimate code RELAP5/Mod3.2. (author)

  12. Identification of the Procedural Accidents During Root Canal Preparation Using Digital Intraoral Radiography and Cone Beam Computed Tomography

    OpenAIRE

    Csinszka K.-Ivácson A.-; Maria Monea Adriana; Monica Monea; Mihai Pop; Angela Borda

    2016-01-01

    Crown or root perforation, ledge formation, fractured instruments and perforation of the roots are the most important accidents which appear during endodontic therapy. Our objective was to evaluate the value of digital intraoral periapical radiographs compared to cone beam computed tomography images (CBCT) used to diagnose some procedural accidents. Material and methods: Eleven extracted molars were used in this study. A total of 18 perforations and 13 ledges were created artifically and 10 i...

  13. Estimated residual Magnetic Field acting on the Circulating Beam in the LHC Septum Magnets MSI and MSD - Shielding Efficiency

    CERN Document Server

    Gyr, Marcel

    2000-01-01

    Computation of the residual field inside the shielded vacuum chambers of the circulating beams that pass through the septum holes of the MSI and MSD magnets is very impractical because of the disproportionate effort involved in obtaining meaningful results. Therefore, a short model has been built to measure the order of magnitude of the residual field inside the LHC vacuum chambers. It is found, that a 0.9 mm thick µ-metal (or Permalloy$^{TM}$) shielding is sufficient to reduce the field, which is experienced by the circulating beam, below the level of the earth's field.

  14. RELAP5/MOD2. 5 analysis of the HFBR (High Flux Beam Reactor) for a loss of power and coolant accident

    Energy Technology Data Exchange (ETDEWEB)

    Slovik, G.C.; Rohatgi, U.S.; Jo, Jae.

    1990-05-01

    A set of postulated accidents were evaluated for the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory. A loss of power accident (LOPA) and a loss of coolant accident (LOCA) were analyzed. This work was performed in response to a DOE review that wanted to update the understanding of the thermal hydraulic behavior of the HFBR during these transients. These calculations were used to determine the margins to fuel damage at the 60 MW power level. The LOPA assumes all the backup power systems fail (although this event is highly unlikely). The reactor scrams, the depressurization valve opens, and the pumps coast down. The HFBR has down flow through the core during normal operation. To avoid fuel damage, the core normally goes through an extended period of forced down flow after a scram before natural circulation is allowed. During a LOPA, the core will go into flow reversal once the buoyancy forces are larger than the friction forces produced during the pump coast down. The flow will stagnate, reverse direction, and establish a buoyancy driven (natural circulation) flow around the core. Fuel damage would probably occur if the critical heat flux (CHF) limit is reached during the flow reversal event. The RELAP5/MOD2.5 code, with an option for heavy water, was used to model the HFBR and perform the LOPA calculation. The code was used to predict the time when the buoyancy forces overcome the friction forces and produce upward directed flow in the core. The Monde CHF correlation and experimental data taken for the HFBR during the design verification phase in 1963 were used to determine the fuel damage margin. 20 refs., 40 figs., 11 tabs.

  15. RELAP5/MOD2.5 analysis of the HFBR [High Flux Beam Reactor] for a loss of power and coolant accident

    International Nuclear Information System (INIS)

    Slovik, G.C.; Rohatgi, U.S.; Jo, Jae.

    1990-05-01

    A set of postulated accidents were evaluated for the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory. A loss of power accident (LOPA) and a loss of coolant accident (LOCA) were analyzed. This work was performed in response to a DOE review that wanted to update the understanding of the thermal hydraulic behavior of the HFBR during these transients. These calculations were used to determine the margins to fuel damage at the 60 MW power level. The LOPA assumes all the backup power systems fail (although this event is highly unlikely). The reactor scrams, the depressurization valve opens, and the pumps coast down. The HFBR has down flow through the core during normal operation. To avoid fuel damage, the core normally goes through an extended period of forced down flow after a scram before natural circulation is allowed. During a LOPA, the core will go into flow reversal once the buoyancy forces are larger than the friction forces produced during the pump coast down. The flow will stagnate, reverse direction, and establish a buoyancy driven (natural circulation) flow around the core. Fuel damage would probably occur if the critical heat flux (CHF) limit is reached during the flow reversal event. The RELAP5/MOD2.5 code, with an option for heavy water, was used to model the HFBR and perform the LOPA calculation. The code was used to predict the time when the buoyancy forces overcome the friction forces and produce upward directed flow in the core. The Monde CHF correlation and experimental data taken for the HFBR during the design verification phase in 1963 were used to determine the fuel damage margin. 20 refs., 40 figs., 11 tabs

  16. A fast wire scanner, used to measure the transverse density distribution of beams circulating in an accelerator or storage ring.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Fast wire scanners are used to measure the transverse density distribution of beams circulating in an accelerator or storage ring. In order to minimize blow-up of the beam through multiple Coulomb scattering, the wires are very thin (in the version shown here it is actually a twisted strand of carbon fibres with a total diameter of about 25 microns) and are swept through the beam at high speed (a linear motor, not mounted here, accelerates the wires to up to 20 m/s). One measures either the secondary emission current from the wire, or the signal from a scintillator/photomultiplier combination downstream from the wire scanner receiving the shower from nuclear reactions of beam particles with the wire nuclei. There are four such fast wire scanners in the 26 GeV PS and eight in the 1.4 GeV Booster.

  17. 3. Workshop for IAEA ICSP on Integral PWR Design Natural Circulation Flow Stability and Thermo-hydraulic Coupling of Containment and Primary System during Accidents. Presentations

    International Nuclear Information System (INIS)

    2012-04-01

    Most advanced nuclear power plant designs adopted several kinds of passive systems. Natural circulation is used as a key driving force for many passive systems and even for core heat removal during normal operation such as NuScale, CAREM, ESBWR and Indian AHWR designs. Simulation of natural circulation phenomena is very challenging since the driving force of it is weak compared to forced circulation and involves a coupling between primary system and containment for integral type reactor. The IAEA ICSP (International Collaborative Standard Problem) on 'Integral PWR Design Natural Circulation Flow Stability and Thermo-hydraulic Coupling of Containment and Primary System during Accidents' was proposed within the CRP on 'Natural Circulation Phenomena, Modelling, and Reliability of Passive Systems that utilize Natural Circulation'. Oregon State University (OSU) of USA offered to host this ICSP. This ICSP plans to conduct the following experiments and blind/open simulations with system codes: 1. Quasi-steady state operation with different core power levels: Conduct quasi-steady state operation with step-wise increase of core power level in order to observe single phase natural circulation flow according to power level. The experimental facility and operating conditions for an integral PWR will be used. 2. Thermo-hydraulic Coupling between Primary system and Containment: Conduct a loss of feedwater transient with subsequent ADS blowdown and long term cooling to determine the progression of a loss of feedwater transient by natural circulation through primary and containment systems. These tests would examine the blowdown phase as well as the long term cooling using sump natural circulation by coupling the primary to containment systems. This data could be used for the evaluation of system codes to determine if they model specific phenomena in an accurate manner. OSU completed planned two ICSP tests in July 2011 and real initial and boundary conditions measured from the

  18. Risk of Fatal Cerebrovascular Accidents after External Beam Radiation Therapy for Early Stage Glottic Larynx Cancer

    Science.gov (United States)

    Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O’Malley, Bert; Weinstein, Gregory S.; Bekelman, Justin E.

    2013-01-01

    Background This study compared the risk of fatal cerebrovascular accidents (CVA) in patients with early stage glottic larynx cancer receiving surgery or external beam radiation therapy (EBRT). Methods and Materials Using a competing risks survival analysis, we compared the risk of death due to CVA among patients with early stage glottic larynx cancer receiving surgery or EBRT in the SEER database. Results The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8 %; 95% CI 2.3%–3.4%) compared to surgery (1.5 %; 95% CI 0.8 %–2.3%, p= 0.024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted HR 1.75; 95% CI 1.04–2.96, p= 0.037). Conclusion Treatment of early stage glottic larynx cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. PMID:23595858

  19. Creation of matter wave Bessel beams and observation of quantized circulation in a Bose–Einstein condensate

    International Nuclear Information System (INIS)

    Ryu, C; Henderson, K C; Boshier, M G

    2014-01-01

    Bessel beams are plane waves with amplitude profiles described by Bessel functions. They are important because they propagate ‘diffraction-free’ and because they can carry orbital angular momentum. Here we report the creation of a Bessel beam of de Broglie matter waves. The Bessel beam is produced by the free evolution of a thin toroidal atomic Bose–Einstein condensate (BEC) which has been set into rotational motion. By attempting to stir it at different rotation rates, we show that the toroidal BEC can only be made to rotate at discrete, equally spaced frequencies, demonstrating that circulation is quantized in atomic BECs. The method used here can be viewed as a form of wavefunction engineering which might be developed to implement cold atom matter wave holography. (paper)

  20. A gas circulation and purification system for gas-cell-based low-energy RI-beam production

    Energy Technology Data Exchange (ETDEWEB)

    Sonoda, T.; Wada, M.; Katayama, I.; Kojima, T. M.; Reponen, M. [RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tsubota, T. [Tokyo KOATSU Co., Ltd., 1-9-8 Shibuya, Shibuyaku, Tokyo 150-0002 (Japan)

    2016-06-15

    A gas circulation and purification system was developed at the RIKEN Radioactive Isotope Beam Factory that can be used for gas-cell-based low-energy RI-beam production. A high-flow-rate gas cell filled with one atmosphere of buffer gas (argon or helium) is used for the deceleration and thermalization of high-energy RI-beams. The exhausted buffer gas is efficiently collected using a compact dry pump and returned to the gas cell with a recovery efficiency of >97%. The buffer gas is efficiently purified using two gas purifiers as well as collision cleaning, which eliminates impurities in the gas. An impurity level of one part per billion is achieved with this method.

  1. Identification of the Procedural Accidents During Root Canal Preparation Using Digital Intraoral Radiography and Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Csinszka K.-Ivácson A.-

    2016-09-01

    Full Text Available Crown or root perforation, ledge formation, fractured instruments and perforation of the roots are the most important accidents which appear during endodontic therapy. Our objective was to evaluate the value of digital intraoral periapical radiographs compared to cone beam computed tomography images (CBCT used to diagnose some procedural accidents. Material and methods: Eleven extracted molars were used in this study. A total of 18 perforations and 13 ledges were created artifically and 10 instruments were fractured in the root canals. Digital intraoral periapical radiographs from two angles and CBCT scans were made with the teeth fixed in position. The images were evaluated and the number of detected accidents were stated in percentages. Statistical analysis was performed using the chi square-test. Results: On digital periapical radiographs the evaluators identified 12 (66.66% perforations, 10 (100 % separated instruments and 10 (76.9% created ledges. The CBCT scans made possible the recognition of 17 (94.66 % perforations, 9 (90 % separated instruments and 13 (100% ledges. The totally recognized accidental procedures showed significant differences between the two groups. (p<0.05 Conclusion: Digital periapical radiographs are the most common imaging modalities used during endodontic treatments. Though, the CBCT allows a better identification of the procedural accidents.

  2. Evaluation of transient natural circulation behavior during accident in low power/shutdown condition of YGN units 3/4

    International Nuclear Information System (INIS)

    Bang, Young Seok; Kim, Kap; Seul, Kwang Won; Kim, Hho Jung

    1997-01-01

    A transient natural circulation behavior during a LOCA at hot-standby operation is evaluated for YGN Units 3/4. The plant initial condition is determined within the EOP limitation as suitable to hot-standby mode and the transient scenario is prepared as relevant to evaluation of transient natural circulation. A 0.4% cold leg break with loss of off-site power is calculated with RELAP5/MOD3.2, whose predictability has been verified for SBLOCA natural circulation test, S-NC-8B. Through one hour transient analysis, it is found that the plant has its own decay heat removal capability by natural circulation following a LOCA at hot-standby mode. Additional calculation is performed to investigate an effect of HPSI flow on natural circulation

  3. Ultrafast harmonic rf kicker design and beam dynamics analysis for an energy recovery linac based electron circulator cooler ring

    Directory of Open Access Journals (Sweden)

    Yulu Huang

    2016-08-01

    Full Text Available An ultrafast kicker system is being developed for the energy recovery linac (ERL based electron circulator cooler ring (CCR in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously named MEIC. In the CCR, the injected electron bunches can be recirculated while performing ion cooling for 10–30 turns before the extraction, thus reducing the recirculation beam current in the ERL to 1/10−1/30 (150  mA-50  mA of the cooling beam current (up to 1.5 A. Assuming a bunch repetition rate of 476.3 MHz and a recirculating factor of 10 in the CCR, the kicker is required to operate at a pulse repetition rate of 47.63 MHz with pulse width of around 2 ns, so that only every 10th bunch in the CCR will experience a transverse kick while the rest of the bunches will not be disturbed. Such a kicker pulse can be synthesized by ten harmonic modes of the 47.63 MHz kicker pulse repetition frequency, using up to four quarter wavelength resonator (QWR based deflecting cavities. In this paper, several methods to synthesize such a kicker waveform will be discussed and a comparison of their beam dynamics performance is made using ELEGANT. Four QWR cavities are envisaged with high transverse shunt impedance requiring less than 100 W of total rf power for a Flat-Top kick pulse. Multipole fields due to the asymmetry of this type of cavity are analyzed. The transverse emittance growth due to the sextupole component is simulated in ELEGANT. Off-axis injection and extraction issues and beam optics using a multicavity kick-drift scheme will also be discussed.

  4. Using the circulating beam in the Fermilab antiproton accumulator for experiments

    International Nuclear Information System (INIS)

    MacLachlan, J.A.

    1988-01-01

    The Fermilab Accumulator is a storage ring optimized for stacking and stochastic cooling 8 GeV antiprotons for the Tevatron collider. Minor modifications have been made to provide for beam in the energy range 8.0-2.9 GeV of luminosity /approximately/10 31 cm -2 s/sup - 1/ with a hydrogen jet internal target. Experience to date consists of machine studies and detector engineering run with protons. 7 refs

  5. Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo

    CERN Document Server

    Shiltsev, V.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N.; Reilly, R.; Still, D.; Tesarek, R.; Zagel, J.; Peggs, S.; Assmann, R.; Previtali, V.; Scandale, W.; Chesnokov, Y.; Yazynin, I.; Guidi, V.; Ivanov, Y.

    2010-01-01

    The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding be...

  6. Risk of fatal cerebrovascular accidents after external beam radiation therapy for early-stage glottic laryngeal cancer.

    Science.gov (United States)

    Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O'Malley, Bert; Weinstein, Gregory S; Bekelman, Justin E

    2014-05-01

    This study compared the risk of fatal cerebrovascular accidents (CVAs) in patients with early-stage glottic laryngeal cancer receiving surgery or external beam radiation therapy (EBRT). Using a competing risks survival analysis, we compared the risk of death because of CVA among patients with early-stage glottic laryngeal cancer receiving surgery or EBRT in the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8%; 95% confidence interval [CI], 2.3% to 3.4%) compared to surgery (1.5%; 95% CI, 0.8% to 2.3%; p = .024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted hazard ratio [HR], 1.75; 95% CI, 1.04-2.96; p = .037). Treatment for early-stage glottic laryngeal cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. Copyright © 2013 Wiley Periodicals, Inc.

  7. Usefulness of measurement of circulation time using MgSO4 : correlation with time-density curve using electron beam computed tomography

    International Nuclear Information System (INIS)

    Kim, Byung Ki; Lee, Hui Joong; Lee, Jong Min; Kim, Yong Joo; Kang, Duck Sik

    1999-01-01

    To determine the usefulness of MgSO 4 for measuring the systemic circulation time. Systemic circulation time, defined as elapsed time from the injection of MgSO 4 solution to the point of pharyngeal burning sensation, was measured in 63 volunteers. MgSO 4 was injected into a superficial vein of an upper extremity. Using dynamic electron beam computed tomography at the level of the abdominal aorta and celiac axis, a time-intensity curve was plotted, and for these two locations, maximal enhancement time was compared. For 60 of the 63 subjects, both systemic circulation time and maximal enhancement time were determined. Average systemic circulation time was 17.4 (SD:3.6) secs. and average maximal enhancement times at the level of the abdominal aorta and celiac axis were 17.5 (SD:3.0) secs. and 18.5 (SD:3.2) secs., respectively. Correlation coefficients between systemic circulation time and maximal enhancement time for the abdominal aorta and celiac axis were 0.73 (p 4 injection and maximal enhancement time for the abdominal aorta showed significant correlation. Thus, to determine the appropriate scanning time in contrast-enhanced radiological studies, MgSO 4 can be used instead of a test bolus study

  8. Development of a Bunched Beam Electron Cooler based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Stephen V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hannon, Fay E. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, Andrew M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2018-01-01

    Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires novel use of bunched-beam cooling. There are two designs for such a cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second uses a circulating ring to enhance both peak and average currents experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.

  9. Natural Circulation in the Blanket Heat Removal System During a Loss-of-Pumping Accident (LOFA) Based on Initial Conceptual Design

    International Nuclear Information System (INIS)

    Hamm, L.L.

    1998-01-01

    A transient natural convection model of the APT blanket primary heat removal (HR) system was developed to demonstrate that the blanket could be cooled for a sufficient period of time for long term cooling to be established following a loss-of-flow accident (LOFA). The particular case of interest in this report is a complete loss-of-pumping accident. For the accident scenario in which pumps are lost in both the target and blanket HR systems, natural convection provides effective cooling of the blanket for approximately 68 hours, and, if only the blanket HR systems are involved, natural convection is effective for approximately 210 hours. The heat sink for both of these accident scenarios is the assumed stagnant fluid and metal on the secondary sides of the heat exchangers

  10. 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.)

  11. Framework for consistent traffic and accident statistical data bases = Cadre pour des bases de données statistiques cohérentes sur la circulation et les accidents.

    NARCIS (Netherlands)

    OECD Scientific Expert Group T8

    1988-01-01

    The OECD Road Transport Research Scientific Expert Group T8 "Framework for Consistent Traffic and Accident Statistical Data Bases" was confronted with the old problem of the inconsistency of data between countries, and the lack of some data altogether, especially traffic data for use as a measure of

  12. Blanket Module Boil-Off Times during a Loss-of-Coolant Accident - Case 0: with Beam Shutdown only

    International Nuclear Information System (INIS)

    Hamm, L.L.

    1998-01-01

    This report is one of a series of reports that document LBLOCA analyses for the Accelerator Production of Tritium primary blanket Heat Removal system. This report documents the analysis results of a LBLOCA where the accelerator beam is shut off without primary pump trips and neither the RHR nor the cavity flood systems operation

  13. Accidents - Chernobyl accident

    International Nuclear Information System (INIS)

    2004-01-01

    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. Effect of kinetic parameters on simultaneous ramp reactivity insertion plus beam tube flooding accident in a typical low enriched U{sub 3}Si{sub 2}-Al fuel-based material testing reactor-type research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, Rubina; Mirza, Nasir M. [Dept. of, Physics, Air University, Islamabad (Pakistan); Mirza, Sikander M. [Dept. of, Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Post Office Nilore, Islamabad (Pakistan)

    2017-06-15

    This work looks at the effect of changes in kinetic parameters on simultaneous reactivity insertions and beam tube flooding in a typical material testing reactor-type research reactor with low enriched high density (U{sub 3}Si{sub 2}-Al) fuel. Using a modified PARET code, various ramp reactivity insertions (from $0.1/0.5 s to $1.3/0.5 s) plus beam tube flooding ($0.5/0.25 s) accidents under uncontrolled conditions were analyzed to find their effects on peak power, net reactivity, and temperature. Then, the effects of changes in kinetic parameters including the Doppler coefficient, prompt neutron lifetime, and delayed neutron fractions on simultaneous reactivity insertion and beam tube flooding accidents were analyzed. Results show that the power peak values are significantly sensitive to the Doppler coefficient of the system in coupled accidents. The material testing reactor-type system under such a coupled accident is not very sensitive to changes in the prompt neutron life time; the core under such a coupled transient is not very sensitive to changes in the effective delayed neutron fraction.

  15. Postulated accidents

    International Nuclear Information System (INIS)

    Ullrich, W.

    1980-01-01

    This lecture on 'Postulated Accidents' is the first of a series of lectures on the dynamic and transient behaviour of nuclear power plants, especially pressurized water reactors. The main points covered will be: Reactivity Accidents, Transients (Intact Loop) and Loss of Cooland Accidents (LOCA) including small leak. This lecture will discuss the accident analysis in general, the definition of the various operational phases, the accident classification, and, as an example, an accident sequence analysis on the basis of 'Postulated Accidents'. (orig./RW)

  16. Accident management

    International Nuclear Information System (INIS)

    Lutz, R.J.; Monty, B.S.; Liparulo, N.J.; Desaedeleer, G.

    1989-01-01

    The foundation of the framework for a Severe Accident Management Program is the contained in the Probabilistic Safety Study (PSS) or the Individual Plant Evaluations (IPE) for a specific plant. The development of a Severe Accident Management Program at a plant is based on the use of the information, in conjunction with other applicable information. A Severe Accident Management Program must address both accident prevention and accident mitigation. The overall Severe Accident Management framework must address these two facets, as a living program in terms of gathering the evaluating information, the readiness to respond to an event. Significant international experience in the development of severe accident management programs exist which should provide some direction for the development of Severe Accident Management in the U.S. This paper reports that the two most important elements of a Severe Accident Management Program are the Emergency Consultation process and the standards for measuring the effectiveness of individual Severe Accident Management Programs at utilities

  17. Unavoidable Accident

    OpenAIRE

    Grady, Mark F.

    2009-01-01

    In negligence law, "unavoidable accident" is the risk that remains when an actor has used due care. The counterpart of unavoidable accident is "negligent harm." Negligence law makes parties immune for unavoidable accident even when they have used less than due care. Courts have developed a number of methods by which they "sort" accidents to unavoidable accident or to negligent harm, holding parties liable only for the latter. These sorting techniques are interesting in their own right and als...

  18. Compensated linac beam colliding with a stored beam

    International Nuclear Information System (INIS)

    Csonka, P.L.; Oregon Univ., Eugene

    1981-01-01

    The disruptive effect of a linac beam on a beam circulating in a storage ring can be reduced by compensating for the space charge of the linac beam with a beam which is oppositely charged, may have different bunchlength as well as lower energy, and need not be circulating in a storage ring. (orig.)

  19. Preventing accidents

    Science.gov (United States)

    2005-08-01

    As the most effective strategy for improving safety is to prevent accidents from occurring at all, the Volpe Center applies a broad range of research techniques and capabilities to determine causes and consequences of accidents and to identify, asses...

  20. Specific features of RBMK severe accidents progression and approach to the accident management

    International Nuclear Information System (INIS)

    Vasilevskij, V.P.; Nikitin, Yu.M.; Petrov, A.A.; Potapov, A.A.; Cherkashov, Yu.M.

    2001-01-01

    Fundamental construction features of the LWGR facilities (absence of common external containment shell, disintegrated circulation circuit and multichannel reactor core, positive vapor reactivity coefficient, high mass of thermally capacious graphite moderator) predetermining development of assumed heavy non-projected accidents and handling them are treated. Rating the categories of the reactor core damages for non-projected accidents and accident types producing specific grope of damages is given. Passing standard non-projected accidents, possible methods of attack accident consequences, as well as methods of calculated analysis of non-projected accidents are demonstrated [ru

  1. APT Blanket System Loss-of-Flow Accident (LOFA) Analysis Based on Initial Conceptual Design - Case 1: with Beam Shutdown and Active RHR

    International Nuclear Information System (INIS)

    Hamm, L.L.

    1998-01-01

    This report is one of a series of reports that document normal operation and accident simulations for the Accelerator Production of Tritium (APT) blanket heat removal system. These simulations were performed for the Preliminary Safety Analysis Report

  2. Accident management for severe accidents

    International Nuclear Information System (INIS)

    Bari, R.A.; Pratt, W.T.; Lehner, J.; Leonard, M.; Disalvo, R.; Sheron, B.

    1988-01-01

    The management of severe accidents in light water reactors is receiving much attention in several countries. The reduction of risk by measures and/or actions that would affect the behavior of a severe accident is discussed. The research program that is being conducted by the US Nuclear Regulatory Commission focuses on both in-vessel accident management and containment and release accident management. The key issues and approaches taken in this program are summarized. 6 refs

  3. Effect of natural circulation on RCS depressurization strategy in PWR NPP

    International Nuclear Information System (INIS)

    Zhang Kun; Tong Lili; Cao Xuewu

    2009-01-01

    The natural circulation model of Chinese Qinshan Nuclear Power Plant (NPP) Unit 2 is built using SCDAP/RELAP5 code. Selecting TMLB' accident as the base sequence, this paper analyzes the natural circulation phenomena in high-pressure core melt severe accident. In order to study the effect of natural circulation on RCS depressurization strategy, the accident progressions of RCS depressurization with and without natural circulation are simulated, respectively. According to the results, the natural circulation can delay the initiation of RCS depressurization and the whole accident progression, but it does not evidently influence the results of RCS depressurization. (authors)

  4. Nuclear accidents

    International Nuclear Information System (INIS)

    1987-01-01

    On 27 May 1986 the Norwegian government appointed an inter-ministerial committee of senior officials to prepare a report on experiences in connection with the Chernobyl accident. The present second part of the committee's report describes proposals for measures to prevent and deal with similar accidents in the future. The committee's evaluations and proposals are grouped into four main sections: Safety and risk at nuclear power plants; the Norwegian contingency organization for dealing with nuclear accidents; compensation issues; and international cooperation

  5. The beam dump tunnels

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

  6. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  7. Natural circulation in reactor coolant system

    International Nuclear Information System (INIS)

    Han, J.T.

    1987-01-01

    Reactor coolant system (RCS) natural circulation in a PWR is the buoyancy-driven coolant circulation between the core and the upper-plenum region (in-vessel circulation) with or without a countercurrent flow in the hot leg piping between the vessel and steam generators (ex-vessel circulation). This kind of multidimensional bouyancy-driven flow circulation serves as a means of transferring the heat from the core to the structures in the upper plenum, hot legs, and possibly steam generators. As a result, the RCS piping and other pressure boundaries may be heated to high temperatures at which the structural integrity is challenged. RCS natural circulation is likely to occur during the core uncovery period of the TMLB' accident in a PWR when the vessel upper plenum and hot leg are already drained and filled with steam and possibly other gaseous species. RCS natural circulation is being studied for the Surry plant during the TMLB' accident in which station blackout coincides with the loss of auxiliary feedwater and no operator actions. The effects of the multidimensional RCS natural circulation during the TMLB' accident are discussed

  8. Normal accidents

    International Nuclear Information System (INIS)

    Perrow, C.

    1989-01-01

    The author has chosen numerous concrete examples to illustrate the hazardousness inherent in high-risk technologies. Starting with the TMI reactor accident in 1979, he shows that it is not only the nuclear energy sector that bears the risk of 'normal accidents', but also quite a number of other technologies and industrial sectors, or research fields. The author refers to the petrochemical industry, shipping, air traffic, large dams, mining activities, and genetic engineering, showing that due to the complexity of the systems and their manifold, rapidly interacting processes, accidents happen that cannot be thoroughly calculated, and hence are unavoidable. (orig./HP) [de

  9. 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...

  10. Radiation accidents

    International Nuclear Information System (INIS)

    Nenot, J.C.

    1996-01-01

    Analysis of radiation accidents over a 50 year period shows that simple cases, where the initiating events were immediately recognised, the source identified and under control, the medical input confined to current handling, were exceptional. In many cases, the accidents were only diagnosed when some injuries presented by the victims suggested the radiological nature of the cause. After large-scale accidents, the situation becomes more complicated, either because of management or medical problems, or both. The review of selected accidents which resulted in severe consequences shows that most of them could have been avoided; lack of regulations, contempt for rules, human failure and insufficient training have been identified as frequent initiating parameters. In addition, the situation was worsened because of unpreparedness, insufficient planning, unadapted resources, and underestimation of psychosociological aspects. (author)

  11. 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.

  12. Radiation accidents

    International Nuclear Information System (INIS)

    Poplavskij, K.K.; Smorodintseva, G.I.

    1978-01-01

    On the basis of a critical analysis of the available data on causes and consequences of radiation accidents (RA), a classification of RA by severity (five groups of accidents) according to biomedical consequences and categories of exposed personnel is proposed. A RA is defined and its main characteristics are described. Methods of RA prevention are proposed, as is a plan of specific measures to deal with RA in accordance with the proposed classification

  13. Production of the heat exchanger tubes, which will cool down the LHC magnets, and of the cold bore tubes, in which the proton beams will circulate, is due to be completed around the end of 2004. These essential components of the LHC magnets are receiving their finishing touches at CERN : cold bore tubes

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Insulation of the cold bore tubes in which the LHC beams will circulate takes place in Building 927. In the background, Bruno Meunier checks the wrapping machine while, in the foreground, Olivier Vasseur removes the polyester wrapping that covers the tube's insulating layers.

  14. Criticality accident:

    International Nuclear Information System (INIS)

    Canavese, Susana I.

    2000-01-01

    A criticality accident occurred at 10:35 on September 30, 1999. It occurred in a precipitation tank in a Conversion Test Building at the JCO Tokai Works site in Tokaimura (Tokai Village) in the Ibaraki Prefecture of Japan. STA provisionally rated this accident a 4 on the seven-level, logarithmic International Nuclear Event Scale (INES). The September 30, 1999 criticality accident at the JCO Tokai Works Site in Tokaimura, Japan in described in preliminary, technical detail. Information is based on preliminary presentations to technical groups by Japanese scientists and spokespersons, translations by technical and non-technical persons of technical web postings by various nuclear authorities, and English-language non-technical reports from various news media and nuclear-interest groups. (author)

  15. Tchernobyl accident

    International Nuclear Information System (INIS)

    1986-06-01

    First, R.M.B.K type reactors are described. Then, safety problems are dealt with reactor control, behavior during transients, normal loss of power and behavior of the reactor in case of leak. A possible scenario of the accident of Tchernobyl is proposed: events before the explosion, possible initiators, possible scenario and events subsequent to the core meltdown (corium-concrete interaction, interaction with the groundwater table). An estimation of the source term is proposed first from the installation characteristics and the supposed scenario of the accident, and from the measurements in Europe; radiological consequences are also estimated. Radioactivity measurements (Europe, Scandinavia, Western Europe, France) are given in tables (meteorological maps and fallouts in Europe). Finally, a description of the site is given [fr

  16. Accident: Reminder

    CERN Multimedia

    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

  17. Beam-Beam Effects

    International Nuclear Information System (INIS)

    Herr, W; Pieloni, T

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities

  18. Feature article. Fukushima Daiichi NPP accident

    International Nuclear Information System (INIS)

    Ekarinai, Masashi; Ake, Yutaka; Narabayashi, Tadashi

    2011-01-01

    This special feature article consisted of five reports and the minutes of emergency discussion meeting on Fukushima Daiichi Nuclear Power Plant (NPP) accident. Effects of the accident on future electricity supply of electric utilities and also on business development of nuclear industries were discussed. Activities of senior network team of atomic energy society of Japan (AESJ) to conduct severe accident analysis and early restoration from the accident were introduced. Circulating injection reactor cooling system and zeolite decontamination system of accumulated contaminated water was proposed. Effects of the accident on overseas reaction on nuclear development were also reported as well as personal experience of the professor in the US west coast on communications. (T. Tanaka)

  19. Prevention of pedestrian accidents.

    OpenAIRE

    Kendrick, D

    1993-01-01

    Child pedestrian accidents are the most common road traffic accident resulting in injury. Much of the existing work on road traffic accidents is based on analysing clusters of accidents despite evidence that child pedestrian accidents tend to be more dispersed than this. This paper analyses pedestrian accidents in 573 children aged 0-11 years by a locally derived deprivation score for the years 1988-90. The analysis shows a significantly higher accident rate in deprived areas and a dose respo...

  20. Radiation accidents

    International Nuclear Information System (INIS)

    Saenger, E.L.

    1986-01-01

    It is essential that emergency physicians understand ways to manage patients contaminated by radioactive materials and/or exposed to external radiation sources. Contamination accidents require careful surveys to identify the metabolic pathway of the radionuclides to guide prognosis and treatment. The level of treatment required will depend on careful surveys and meticulous decontamination. There is no specific therapy for the acute radiation syndrome. Prophylactic antibodies are desirable. For severely exposed patients treatment is similar to the supportive care given to patients undergoing organ transplantation. For high-dose extremity injury, no methods have been developed to reverse the fibrosing endarteritis that eventually leads to tissue death so frequently found with this type of injury. Although the Three Mile Island episode of March 1979 created tremendous public concern, there were no radiation injuries. The contamination outside the reactor building and the release of radioiodine were negligible. The accidental fuel element meltdown at Chernobyl, USSR, resulted in many cases of acute radiation syndrome. More than 100,000 people were exposed to high levels of radioactive fallout. The general principles outlined here are applicable to accidents of that degree of severity

  1. Chernobyl accident

    International Nuclear Information System (INIS)

    Bar'yakhtar, V.G.

    1995-01-01

    The monograph contains the catastrophe's events chronology, the efficiency assessed of those measures assumed for their localization as well as their environmental and socio-economic impact. Among materials of the monograph the results are presented of research on the radioactive contamination field forming as well as those concerning the investigation of biogeochemical properties of Chernobyl radionuclides and their migration process in the environment of the Ukraine. The data dealing with biological effects of the continued combined internal and external radioactive influence on plants, animals and human health under the circumstances of Chernobyl accident are of the special interest. In order to provide the scientific generalizing information on the medical aspects of Chernobyl catastrophe, the great part of the monograph is allotted to appraise those factors affecting the health of different population groups as well as to depict clinic aspects of Chernobyl events and medico-sanitarian help system. The National Programme of Ukraine for the accident consequences elimination and population social protection assuring for the years 1986-1993 and this Programme concept for the period up to the year 2000 with a special regard of the world community participation there

  2. Chernobyl accident

    International Nuclear Information System (INIS)

    Capra, D.; Facchini, U.; Gianelle, V.; Ravasini, G.; Bacci, P.

    1988-01-01

    The radioactive cloud released during the Chernobyl accident reached the Padana plain and Lombardy in the night of April 30th 1986; the cloud remained in the northern Italian skies for a few days and then disappeared either dispersed by winds and washed by rains. The evidence in atmosphere of radionuclides as Tellurium, Iodine, Cesium, was promptly observed. The intense rain, in first week of may, washed the radioactivity and fall-out contamined the land, soil, grass. The present work concerns the overall contamination of the Northern Italy territory and in particular the radioactive fall-out in the Lakes region. Samples of soil have been measured at the gamma spectroscope; a correlation is found between the radionuclides concentration in soil samples and the rain intensity, when appropriate deposition models are considered. A number of measurements has been done on the Como'lake ecosystem: sediments, plankton, fishes and the overall fall-out in the area has been investigated

  3. Self-reported accidents

    DEFF Research Database (Denmark)

    Møller, Katrine Meltofte; Andersen, Camilla Sloth

    2016-01-01

    The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals.......The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals....

  4. Accident Assessment

    International Nuclear Information System (INIS)

    Tripputi, Ivo; Lund, Ingemar

    2002-01-01

    There is a general feeling that decommissioning is an activity involving limited risks, compared to NPP operation, and in particular risks involving the general public. This is technically confirmed by licensing analysis and evaluations, where, once the spent fuel has been removed from the plant, the radioactivity inventory available to be released to the environment is very limited. Decommissioning activities performed so far in the world have also confirmed the first assumptions and no specific issue has been identified, in this field, to justify a completely new approach. Commercial interests in international harmonization, which could drive an in-depth discussion about the bases of this approach, are weak at the moment. However, there are several reasons why a discussion in an international framework about the Safety Case for decommissioning (and, in particular, about Accident Assessment) may be considered necessary and important, and why it may show some specific and peculiar aspects. An effort for a comprehensive and systematic D and D accident safety assessment of the decommissioning process is justified. It is necessary also to explore in a holistic way the aspects of industrial safety, and develop tools for the decision-making process optimization. The expected results are the implementation of appropriate and optimized protective measures in any event and of adequate on/off-site emergency plans for optimal public and workers protection. The experience from other decommissioning projects and large-scale industrial activities is essential to balance provisions and an Operating Experience review process (specific for decommissioning) should help to focus on real issues

  5. First circulating beam in the AA

    CERN Multimedia

    1980-01-01

    Amongst the crowd in the Control-Room on can distinguish(right to left): - sitting in the middle: Eifionydd Jones, Roy Billinge and Simon van der Meer; - telephoning: Heribert Koziol; - standing in front or slightly behind: Claude Metzger, Andre van der Schueren, Peter Pierce, Dietrich Bloess and Jean-Pierre Riunaud; - sitting on the table (front, left): Stuart Simpson. (See photo 8007094, 8007104, 8007124.)

  6. Accident information needs

    International Nuclear Information System (INIS)

    Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

    1992-01-01

    A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information

  7. Accident information needs

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

    1992-12-31

    A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information.

  8. Accident information needs

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

    1992-01-01

    A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information.

  9. Severe accident phenomena

    International Nuclear Information System (INIS)

    Jokiniemi, J.; Kilpi, K.; Lindholm, I.; Maekynen, J.; Pekkarinen, E.; Sairanen, R.; Silde, A.

    1995-02-01

    Severe accidents are nuclear reactor accidents in which the reactor core is substantially damaged. The report describes severe reactor accident phenomena and their significance for the safety of nuclear power plants. A comprehensive set of phenomena ranging from accident initiation to containment behaviour and containment integrity questions are covered. The report is based on expertise gained in the severe accident assessment projects conducted at the Technical Research Centre of Finland (VTT). (49 refs., 32 figs., 12 tabs.)

  10. Heat transfer phenomena revelant to severe accidents

    International Nuclear Information System (INIS)

    Dallman, R.J.; Duffey, R.B.

    1990-01-01

    A number of aspects of severe accidents have been reviewed, particularly in relation to the heat transfer characteristics and the important phenomena. It is shown that natural circulation, forced convection, and entrainment phenomena are important for both the reactor system and ex-vessel events. It is also shown that the phenomena related to two component enhanced heat transfer is important in the pool of molten core debris, in relation to the potential for attack of the liner structure and the concrete. These mechanisms are discussed within the general context of severe accident progression

  11. Heat transfer phenomena relevant to severe accidents

    International Nuclear Information System (INIS)

    Dallman, R.J.; Duffey, R.B.

    1990-01-01

    A number of aspects of severe accidents have been reviewed, particularly in relation to the heat transfer characteristics and the important phenomena. It is shown that natural circulation, forced convection, and entrainment phenomena are important for both the reactor system and ex-vessel events. It is also shown that the phenomena related to two component enhanced heat transfer is important in the pool of molten core debris, in relation to the potential for attack of the liner structure and the concrete. These mechanisms are discussed within the general context of severe accident progression. 26 refs

  12. Experimental study of the natural circulation phenomena

    International Nuclear Information System (INIS)

    Sabundjian, Gaiane; Andrade, Delvonei Alves de; Umbehaun, Pedro E.; Torres, Walmir M.; Castro, Alfredo Jose Alvim de; Belchior Junior, Antonio; Rocha, Ricardo Takeshi Vieira da; Damy, Osvaldo Luiz de Almeida; Torres, Eduardo

    2006-01-01

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)

  13. The development of severe accident analysis technology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heuy Dong; Cho, Sung Won; Kim, Sang Baek; Park, Jong Hwa; Lee, Kyu Jung; Park, Lae Joon; Hu, Hoh; Hong, Sung Wan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-07-01

    The objective of the development of severe accident analysis technology is to understand the severe accident phenomena such as core melt progression and to provide a reliable analytical tool to assess severe accidents in a nuclear power plant. Furthermore, establishment of the accident management strategies for the prevention/mitigation of severe accidents is also the purpose of this research. The study may be categorized into three areas. For the first area, two specific issues were reviewed to identify the further research direction, that is the natural circulation in the reactor coolant system and the fuel-coolant interaction as an in-vessel and an ex-vessel phenomenological study. For the second area, the MELCOR and the CONTAIN codes have been upgraded, and a validation calculation of the MELCOR has been performed for the PHEBUS-B9+ experiment. Finally, the experimental program has been established for the in-vessel and the ex-vessel severe accident phenomena with the in-pile test loop in KMRR and the integral containment test facilities, respectively. (Author).

  14. Accidents in radiotherapy: Lack of quality assurance?

    International Nuclear Information System (INIS)

    Novotny, J.

    1997-01-01

    About 150 radiological accidents, involving more than 3000 patients with adverse effects, 15 patient's fatalities and about 5000 staff and public exposures have been collected and analysed. Out of 67 analysed accidents in external beam therapy 22% has been caused by wrong calculation of the exposure time or monitor units, 13% by inadequate review of patient's chart, 12% by mistakes in the anatomical area to be treated. The remaining 35% can be attributed to 17 different causes. The most common mistakes in brachytherapy were wrong activities of sources used for treatment (20%), inadequate procedures for placement of sources applicators (14%), mistakes in calculating the treatment time (12%), etc. The direct and contributing causes of radiological accidents have been deduced from each event, when it was possible and categorized into 9 categories: mistakes in procedures (30%), professional mistakes (17%), communication mistakes (15%), lack of training (8.5%), interpretation mistakes (7%), lack of supervision (6%), mistakes in judgement (6%), hardware failures (5%), software and other mistakes (5.5%). Three types of direct and contributing causes responsible for almost 62% of all accidents are directly connected to the quality assurance of treatment. The lessons learnt from the accidents are related to frequencies of direct and contributing factors and show that most of the accident are caused by lack, non-application of quality assurance (QA) procedures or by underestimating of QA procedures. The international system for collection of accidents and dissemination of lessons learnt from the different accidents, proposed by IAEA, can contribute to better practice in many radiotherapy departments. Most of the accidents could have been avoided, had a comprehensive QA programme been established and properly applied in all radiotherapy departments, whatever the size. (author)

  15. Nuclear accident dosimetry

    International Nuclear Information System (INIS)

    1982-01-01

    The film presents statistical data on criticality accidents. It outlines past IAEA activities on criticality accident dosimetry and the technical documents that resulted from this work. The film furthermore illustrates an international comparison study on nuclear accident dosimetry conducted at the Atomic Energy Research Establishment, Harwell, United Kingdom

  16. Nuclear accident dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-12-31

    The film presents statistical data on criticality accidents. It outlines past IAEA activities on criticality accident dosimetry and the technical documents that resulted from this work. The film furthermore illustrates an international comparison study on nuclear accident dosimetry conducted at the Atomic Energy Research Establishment, Harwell, United Kingdom

  17. Supervisor's accident investigation handbook

    International Nuclear Information System (INIS)

    1980-02-01

    This pamphlet was prepared by the Environmental Health and Safety Department (EH and S) of Lawrence Berkeley Laboratory (LBL) to provide LBL supervisors with a handy reference to LBL's accident investigation program. The publication supplements the Accident and Emergencies section of LBL's Regulations and Procedures Manual, Pub. 201. The present guide discusses only accidents that are to be investigated by the supervisor. These accidents are classified as Type C by the Department of Energy (DOE) and include most occupational injuries and illnesses, government motor-vehicle accidents, and property damages of less than $50,000

  18. LWR and HTGR coolant dynamics: the containment of severe accidents

    International Nuclear Information System (INIS)

    Theofanous, T.G.; Gherson, P.; Nourbakhsh, H.P.; Hu, K.; Iyer, K.; Viskanta, R.; Lommers, L.

    1983-07-01

    This is the final report of a project containing three major tasks. Task I deals with the fundamental aspects of energetic fuel/coolant interactions (steam explosions) as they pertain to LWR core melt accidents. Task II deals with the applied aspects of LWR core melt accident sequences and mechanisms important to containment response, and includes consideration of energetic fuel/coolant interaction events, as well as non-explosive ones, corium material disposition and eventual coolability, and containment pressurization phenomena. Finally, Task III is concerned with HTGR loss of forced circulation accidents. This report is organized into three major parts corresponding to these three tasks respectively

  19. A beam halo event of the ATLAS Experiment

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    Beam halo events: These occur as a single beam of protons is circulating in one direction in LHC, just passing through ATLAS. An outlier particle hits a part of the detector causing a spray of particles.

  20. 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.

  1. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  2. What constitutes a radiology radiation accident

    International Nuclear Information System (INIS)

    Wallace, A.; Edmonds, K.; Hayton, A.; Tingey, D.

    2010-01-01

    Full text: A review of the literature indicates a very small number of articles on radiology radiation accidents. This may be due to there being no agreed definition of the term 'accident' when applied to radiology incidents. As the intensity of X-ray beams and the functionality of various modalities increase there is a consequent development in procedures to which 'high dose' applications are required. We may therefore expect to see more incidents in future. How are we to manage them? Radiology radiation accidents are usually exemplified by deterministic skin burns which may take many weeks or months to become apparent and any procedure leading to a radiation induced fatality is difficult to prove. (author)

  3. The Chernobyl accident consequences

    International Nuclear Information System (INIS)

    2001-04-01

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

  4. Radiation, accidents, society

    International Nuclear Information System (INIS)

    1988-01-01

    This book is meant to be used as a reference book for information officers at the event of a nuclear accident. The main part is edited in alphabetical order to facilitate use under stress. The book gives a short review of the health risks of radiation, and descriptions of accidents that have occured. The index words that have been chosen for the main part of the book have been selected due to experiences in connection with incidents and accidents. (L.E.)

  5. Reactivity insertion accident analysis

    International Nuclear Information System (INIS)

    Moreira, J.M.L.; Nakata, H.; Yorihaz, H.

    1990-04-01

    The correct prediction of postulated accidents is the fundamental requirement for the reactor licensing procedures. Accident sequences and severity of their consequences depend upon the analysis which rely on analytical tools which must be validated against known experimental results. Present work presents a systematic approach to analyse and estimate the reactivity insertion accident sequences. The methodology is based on the CINETHICA code which solves the point-kinetics/thermohydraulic coupled equations with weighted temperature feedback. Comparison against SPERT experimental results shows good agreement for the step insertion accidents. (author) [pt

  6. Nuclear accidents and epidemiology

    International Nuclear Information System (INIS)

    1987-01-01

    A consultation on epidemiology related to the Chernobyl accident was held in Copenhagen in May 1987 as a basis for concerted action. This was followed by a joint IAEA/WHO workshop in Vienna, which reviewed appropriate methodologies for possible long-term effects of radiation following nuclear accidents. The reports of these two meetings are included in this volume, and cover the subjects: 1) Epidemiology related to the Chernobyl nuclear accident. 2) Appropriate methodologies for studying possible long-term effects of radiation on individuals exposed in a nuclear accident. Figs and tabs

  7. 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...

  8. Beam-beam phenomenology

    International Nuclear Information System (INIS)

    Teng, L.C.

    1980-01-01

    In colliding beam storage rings the beam collision regions are generally so short that the beam-beam interaction can be considered as a series of evenly spaced non-linear kicks superimposed on otherwise stable linear oscillations. Most of the numerical studies on computers were carried out in just this manner. But for some reason this model has not been extensively employed in analytical studies. This is perhaps because all analytical work has so far been done by mathematicians pursuing general transcendental features of non-linear mechanics for whom this specific model of the specific system of colliding beams is too parochial and too repugnantly physical. Be that as it may, this model is of direct interest to accelerator physicists and is amenable to (1) further simplification, (2) physical approximation, and (3) solution by analogy to known phenomena

  9. Aspects of severe accidents in transmutation systems

    International Nuclear Information System (INIS)

    Wider, H.U.; Karlson, J.; Jones, A.V.

    2001-01-01

    The different types of transmutation systems under investigation include accelerator driven (ADS) and critical systems. To switch off an accelerator in case of an accident initiation is quite important for all accidents. For a fast ADS the grace times available for doing so depend strongly on the total heat capacity and the natural circulation capability of the primary coolant. Cooling with heavy metal Pb-Bi has considerable advantages in this regard compared to gas cooling. Moreover it allows passive ex-vessel cooling with natural air or water circulation. In the remote likelihood of fuel melting, oxide fuel appears to mix with the Pb-Bi coolant. Fast critical systems that are cooled by Pb-Bi will automatically shut off if the flow or heat sink is lost. Reactivity accidents can be limited by a low total control rod worth. High temperature reactors can achieve only incomplete burning of actinides. If an accelerator is added to increase burn-up, a fast spectrum region is needed, which has a low heat capacity. (author)

  10. Natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Bastos, J.L.F.; Loureiro, L.V.; Rocha, R.T.V. da; Umbehaun, P.E.

    1992-01-01

    Several analytical modelling have been done for steady-state and slow transients conditions, besides more sophisticated studies considering two and three dimensional effects in a very simple geometry. Under severe accident conditions for PWR a code to analyse natural circulation has been developed by Westinghouse. This paper discusses the problem of natural circulation in a complex geometry similar to that of nuclear power plants. A first experiment has been done at the integral test facility of 'Co-ordination of Special Projects-Ministry of Naval Affairs' (Coordenadoria para Projetos Especiais -Ministerio da Marinha, COPESP) for several flux conditions. The results obtained were compared with numerical simulations for the steady-state regime. 09 refs, 05 figs, 01 tab. (B.C.A.)

  11. Circulation pump mounting

    International Nuclear Information System (INIS)

    Skalicky, A.

    1976-01-01

    The suspension is described of nuclear reactor circulating pumps enabling their dilatation with a minimum reverse force consisting of spacing rods supported with one end in the anchor joints and provided with springs and screw joints engaging the circulating pump shoes. The spacing rods are equipped with side vibration dampers anchored in the shaft side wall and on the body of the circulating pump drive body. The negative reverse force F of the spacing rods is given by the relation F=Q/l.y, where Q is the weight of the circulating pump, l is the spatial distance between the shoe joints and anchor joints, and y is the deflection of the circulating pump vertical axis from the mean equilibrium position. The described suspension is advantageous in that that the reverse force for the deflection from the mean equilibrium position is minimal, dynamic behaviour is better, and construction costs are lower compared to suspension design used so far. (J.B.)

  12. Design and study of Engineering Test Facility - Helium Circulator

    International Nuclear Information System (INIS)

    Jiang Huijing; Ye Ping; Zhao Gang; Geng Yinan; Wang Jie

    2015-01-01

    Helium circulator is one of the key equipment of High-temperature Gas-cooled Reactor Pebble-bed Module (HTR-PM). In order to simulate most normal and accident operating conditions of helium circulator in HTR-PM, a full scale, rated flow rate and power, engineering test loop, which was called Engineering Test Facility - Helium Circulator (ETF-HC), was designed and established. Two prototypes of helium circulator, which was supported by Active Magnetic Bearing (AMB) or sealed by dry gas seals, would be tested on ETF-HC. Therefore, special interchangeable design was under consideration. ETF-HC was constructed compactly, which consisted of eleven sub-systems. In order to reduce the flow resistance of the circuit, special ducts, elbows, valves and flowmeters were selected. Two stages of heat exchange loops were designed and a helium - high pressure pure water heat exchanger was applied to ensure water wouldn't be vaporized while simulating accident conditions. Commissioning tests were carried out and operation results showed that ETF-HC meets the requirement of helium circulator operation. On this test facility, different kinds of experiments were supposed to be held, including mechanical and aerodynamic performance tests, durability tests and so on. These tests would provide the features and performance of helium circulator and verify its feasibility, availability and reliability. (author)

  13. Detection of coherent beam-beam modes with digitized beam position monitor signals

    CERN Document Server

    Stancari, G.; White, S.M.

    2014-01-01

    A system for bunch-by-bunch detection of transverse proton and antiproton coherent oscillations in the Fermilab Tevatron collider is described. It is based on the signal from a single beam-position monitor located in a region of the ring with large amplitude functions. The signal is digitized over a large number of turns and Fourier-analyzed offline with a dedicated algorithm. To enhance the signal, band-limited noise is applied to the beam for about 1 s. This excitation does not adversely affect the circulating beams even at high luminosities. The device has a response time of a few seconds, a frequency resolution of $1.6\\times 10^{-5}$ in fractional tune, and it is sensitive to oscillation amplitudes of 60 nm. It complements Schottky detectors as a diagnostic tool for tunes, tune spreads, and beam-beam effects. Measurements of coherent mode spectra are presented and compared with models of beam-beam oscillations.

  14. LANSCE Beam Current Limiter (XL)

    International Nuclear Information System (INIS)

    Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) is an engineered safety system that provides personnel protection from prompt radiation due to accelerated proton beams. The Beam Current Limiter (XL), as an active component of the RSS, limits the maximum average current in a beamline, thus the current available for a beam spill accident. Exceeding the pre-set limit initiates action by the RSS to mitigate the hazard (insertion of beam stoppers in the low energy beam transport). The beam limiter is an electrically isolated, toroidal transformer and associated electronics. The device was designed to continuously monitor beamline currents independent of any external timing. Fail-safe operation was a prime consideration in its development. Fail-safe operation is defined as functioning as intended (due to redundant circuitry), functioning with a more sensitive fault threshold, or generating a fault condition. This report describes the design philosophy, hardware, implementation, operation, and limitations of the device

  15. Domino effect in chemical accidents: main features and accident sequences

    OpenAIRE

    Casal Fàbrega, Joaquim; Darbra Roman, Rosa Maria

    2010-01-01

    The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident scenario, the type of accident, the materials involved, the causes and consequences and the most common accident sequences. The analysis showed that the most frequent causes a...

  16. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Lawrence J.; Bower, Amy S.; Kö hl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-01-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented

  17. Chernobyl accident and Denmark

    International Nuclear Information System (INIS)

    1986-12-01

    The report describes the Chernobyl accident and its consequences for Denmark in particular. It was commissioned by The Secretary of State for the Environment. Volume 2 contains copies of original documents issued by Danish authorities during the first accident phase and afterwards. Evaluations, monitoring data, press releases, legislation acts etc. are included. (author)

  18. Criticality accident in Argentina

    International Nuclear Information System (INIS)

    Oliveira, A.R. de.

    1984-01-01

    A recent criticality type accident, ocurred in Argetina, is commented. Considerations about the nature of the facility where this accident took place, its genesis, type of operation carried out on the day of the event, and the medical aspects involved are done. (Author) [pt

  19. Chernobyl accident and Danmark

    International Nuclear Information System (INIS)

    1986-12-01

    The report describes the Chernobyl accident and its consequences for Denmark in particular. It was commissioned by the Secretary of State for the Environment. Volume 1 contains copies of original documents issued by Danish authorities during the first accident phase and afterwards. Evaluations, monitoring data, press releases, legislation acts etc. are included. (author)

  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

  1. Chapter 6: Accidents

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2018-04-01

    Th chapter 6 presents the accidents of: 1) Stimos (Italy - May, 1975); 2) San Salvador (El Salvador - February 5, 1989); 3) Soreq (Israel - June 21, 1990); 4) Nesvizh (Belarus - October 26, 1991); 5) Illinois (USA - February, 1965); 6)Maryland (EUA - December 11, 1991); 7)Hanoi (Vietnam -November 17, 1992); 8)Fleurus (Belgium - March 11, 2006) and final remarks on accidents.

  2. Booster gold beam injection efficiency and beam loss

    International Nuclear Information System (INIS)

    Zhang, S.Y.; Ahrens, L.A.

    1998-01-01

    The Relativistic Heavy Ion Collider (RHIC) at the BNL requires the AGS to provide Gold beam with the intensity of 10 9 ions per bunch. Over the years, the Tandem Van de Graaff has provided steadily increasing intensity of gold ion beams to the AGS Booster. However, the gold beam injection efficiency at the Booster has been found to decrease with the rising intensity of injected beams. As the result, for Tandem beams of the highest intensity, the Booster late intensity is lower than with slightly lower intensity Tandem beam. In this article, the authors present two experiments associated with the Booster injection efficiency and beam intensity. One experiment looks at the Booster injection efficiency by adjusting the Tandem beam intensity, and another looks at the beam life time while scraping the beam in the Booster. The studies suggest that the gold beam injection efficiency at the AGS Booster is related to the beam loss in the ring, rather than the intensity of injected beam or circulating beam. A close look at the effect of the lost gold ion at the Booster injection leads to the prediction that the lost gold ion creates large number of positive ions, and even larger number of electrons. The lost gold beam is also expected to create large numbers of neutral particles. In 1998 heavy ion run, the production of positive ions and electrons due to the lost gold beam has been observed. Also the high vacuum pressure due to the beam loss, presumably because of the neutral particles it created, has been measured. These results will be reported elsewhere

  3. Radiological accidents in medical practice

    International Nuclear Information System (INIS)

    Cardenas Herrera, Juan

    2012-01-01

    Different radiological accidents that may occur in medical practice are shown. The following topics are focused: accident statistics for medical exposure, accidental medical exposures, radiotherapy accidents and potential accidental scenarios [es

  4. Proton-antiproton colliding beam electron cooling

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Skrinskij, A.N.

    1981-01-01

    A possibility of effective cooling of high-energy pp tilde beams (E=10 2 -10 3 GeV) in the colliding mode by accompanying radiationally cooled electron beam circulating in an adjacent storage ring is studied. The cooling rate restrictions by the pp tilde beam interaction effects while colliding and the beam self-heating effect due to multiple internal scattering are considered. Some techniques permitting to avoid self-heating of a cooling electron beam or suppress its harmful effect on a heavy particle beam cooling are proposed. According to the estimations the cooling time of 10 2 -10 3 s order can be attained [ru

  5. Polarized secondary radioactive beams

    International Nuclear Information System (INIS)

    Zaika, N.I.

    1992-01-01

    Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

  6. Natural Circulation Characteristics of a Symmetric Loop under Inclined Conditions

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available Natural circulation is an important process for primary loops of some marine integrated reactors. The reactor works under inclined conditions when severe accidents happen to the ship. In this paper, to investigate the characteristics of natural circulation, experiments were conducted in a symmetric loop under the inclined angle of 0~45°. A CFD model was also set up to predict the behaviors of the loop beyond the experimental scope. Total circulation flow rate decreases with the increase of inclined angle. Meanwhile one circulation is depressed while the other is enhanced, and accordingly the disparity between the branch circulations arises and increases with the increase of inclined angle. Circulation only takes place in one branch circuit at large inclined angle. Also based on the CFD model, the influences of flow resistance distribution and loop configuration on natural circulation are predicted. The numerical results show that to design the loop with the configuration of big altitude difference and small width, it is favorable to reduce the influence of inclination; however too small loop width will cause severe reduction of circulation ability at large angle inclination.

  7. [Accidents and injuries at work].

    Science.gov (United States)

    Standke, W

    2014-06-01

    In the case of an accident at work, the person concerned is insured by law according to the guidelines of the Sozialgesetzbuch VII as far as the injuries have been caused by this accident. The most important source of information on the incident in question is the accident report that has to be sent to the responsible institution for statutory accident insurance and prevention by the employer, if the accident of the injured person is fatal or leads to an incapacity to work for more than 3 days (= reportable accident). Data concerning accidents like these are sent to the Deutsche Gesetzliche Unfallversicherung (DGUV) as part of a random sample survey by the institutions for statutory accident insurance and prevention and are analyzed statistically. Thus the key issues of accidents can be established and used for effective prevention. Although the success of effective accident prevention is undisputed, there were still 919,025 occupational accidents in 2011, with clear gender-related differences. Most occupational accidents involve the upper and lower extremities. Accidents are analyzed comprehensively and the results are published and made available to all interested parties in an effort to improve public awareness of possible accidents. Apart from reportable accidents, data on the new occupational accident pensions are also gathered and analyzed statistically. Thus, additional information is gained on accidents with extremely serious consequences and partly permanent injuries for the accident victims.

  8. ATHLET validation using accident management experiments

    Energy Technology Data Exchange (ETDEWEB)

    Teschendorff, V.; Glaeser, H.; Steinhoff, F. [Gasellschaft fuer Anlagen - und Reaktorsicherheit (GSR) mbH, Garching (Germany)

    1995-09-01

    The computer code ATHLET is being developed as an advanced best-estimate code for the simulation of leaks and transients in PWRs and BWRs including beyond design basis accidents. The code has features that are of special interest for applications to small leaks and transients with accident management, e.g. initialisation by a steady-state calculation, full-range drift-flux model, and dynamic mixture level tracking. The General Control Simulation Module of ATHLET is a flexible tool for the simulation of the balance-of-plant and control systems including the various operator actions in the course of accident sequences with AM measures. The systematic validation of ATHLET is based on a well balanced set of integral and separate effect tests derived from the CSNI proposal emphasising, however, the German combined ECC injection system which was investigated in the UPTF, PKL and LOBI test facilities. PKL-III test B 2.1 simulates a cool-down procedure during an emergency power case with three steam generators isolated. Natural circulation under these conditions was investigated in detail in a pressure range of 4 to 2 MPa. The transient was calculated over 22000 s with complicated boundary conditions including manual control actions. The calculations demonstrations the capability to model the following processes successfully: (1) variation of the natural circulation caused by steam generator isolation, (2) vapour formation in the U-tubes of the isolated steam generators, (3) break-down of circulation in the loop containing the isolated steam generator following controlled cool-down of the secondary side, (4) accumulation of vapour in the pressure vessel dome. One conclusion with respect to the suitability of experiments simulating AM procedures for code validation purposes is that complete documentation of control actions during the experiment must be available. Special attention should be given to the documentation of operator actions in the course of the experiment.

  9. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2012-09-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to the report, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. This year, the database was revised by adding aircraft accidents in 2010 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2011 database for latest 20 years from 1991 to 2010. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for latest 20 years from 1991 to 2010 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2011 revised database for latest 20 years from 1991 to 2010 shows the followings. The trend of the 2011 database changes little as compared to the last year's one. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. 4 large fixed-wing aircraft accidents, 58 small fixed-wing aircraft accidents, 5 large bladed aircraft accidents and 114 small bladed aircraft accidents occurred. The relevant accidents for evaluating

  10. Re-circulating linac vacuum system

    International Nuclear Information System (INIS)

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-01-01

    The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing

  11. Management of severe accidents

    International Nuclear Information System (INIS)

    Jankowski, M.W.

    1987-01-01

    The definition and the multidimensionality aspects of accident management have been reviewed. The suggested elements in the development of a programme for severe accident management have been identified and discussed. The strategies concentrate on the two tiered approaches. Operative management utilizes the plant's equipment and operators capabilities. The recovery managment concevtrates on preserving the containment, or delaying its failure, inhibiting the release, and on strategies once there has been a release. The inspiration for this paper was an excellent overview report on perspectives on managing severe accidents in commercial nuclear power plants and extending plant operating procedures into the severe accident regime; and by the most recent publication of the International Nuclear Safety Advisory Group (INSAG) considering the question of risk reduction and source term reduction through accident prevention, management and mitigation. The latter document concludes that 'active development of accident management measures by plant personnel can lead to very large reductions in source terms and risk', and goes further in considering and formulating the key issue: 'The most fruitful path to follow in reducing risk even further is through the planning of accident management.' (author)

  12. 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.

  13. Management of severe accidents

    International Nuclear Information System (INIS)

    Jankowski, M.W.

    1988-01-01

    The definition and the multidimensionality aspects of accident management have been reviewed. The suggested elements in the development of a programme for severe accident management have been identified and discussed. The strategies concentrate on the two tiered approaches. Operative management utilizes the plant's equipment and operators capabilities. The recovery management concentrates on preserving the containment, or delaying its failure, inhibiting the release, and on strategies once there has been a release. The inspiration for this paper was an excellent overview report on perspectives on managing severe accidents in commercial nuclear power plants and extending plant operating procedures into the severe accident regime; and by the most recent publication of the International Nuclear Safety Advisory Group (INSAG) considering the question of risk reduction and source term reduction through accident prevention, management and mitigation. The latter document concludes that active development of accident management measures by plant personnel can lead to very large reductions in source terms and risk, and goes further in considering and formulating the key issue: The most fruitful path to follow in reducing risk even further is through the planning of accident management

  14. 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.

  15. Social impact of accidents

    International Nuclear Information System (INIS)

    Kuroda, Isao

    1997-01-01

    There is the quite big difference between technological risk and social risk feeling. Various biases of social and sensational factors on accidents must be considered to recognize this difference. 'How safe is safe enough' is the perpetual thema concerning with not only technology but also sociology. The safety goal in aircraft design and how making effort to improve the present safety status in civil jet aircrafts is discussed as an example of social risk allowance. INSAG under IAEA started to discuss the safety culture after Chernobyl nuclear power plant accident on 1986. Safety culture and risk communication are the most important procedures to relieve the social impact for accidents. (author)

  16. Severe accident behavior

    International Nuclear Information System (INIS)

    Denning, R.S.

    1986-01-01

    The purpose of this paper is to provide an overview of severe accident behavior. The term source term is defined and a brief history of the regulatory use of source term is presented. The processes in severe accidents in light water reactors are described with particular emphasis on the relationships between accident thermal-hydraulics and chemistry. Those factors which have the greatest impact on predicted source terms are identified. Design differences between plants that affect source term estimation are also described. The principal unresolved issues are identified that are the focus of ongoing research and debate in the technical community

  17. Management of accident risks

    International Nuclear Information System (INIS)

    Compes, P.C.

    1987-01-01

    The example of the Chernobyl accident and the statistics of the occurrence of accidents make clear the threat to humanity, if one cannot guarantee successful accident prevention in the use and distribution of the projects aimed at. The science of safety, as it is known in the Wuppertal model, makes its contribution to this vital task for the human community. It makes it necessary to create the essential dates and concepts, the methods, principles and techniques based on them and the associated instrumentation. (DG) [de

  18. Chernobyl accident and Denmark

    International Nuclear Information System (INIS)

    1986-12-01

    The report describes the Chernobyl accident and its consequences for Denmark in particular. It was commissioned by The Secretary of State for the Environment. The event at the accident site, the release and dispersal of radioactive substances into the atmosphere and over Europe, is described. A discussion of the Danish organisation for nuclear emergencies, how it was activated and adapted to the actual situation, is given. A comprehensive description of the radiological contamination in Denmark following the accident and the estimated health effects, is presented. The situation in other European countries is mentioned. (author)

  19. Hybrid beams in the LHC

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The first proton-ion beams were successfully circulated in the LHC a couple of weeks ago. Everything went so smoothly that the LHC teams had planned the first p-Pb collisions for Wednesday, 16 November. Unfortunately, a last-minute problem with a component of the PS required for proton acceleration prevented the LHC teams from making these new collisions. However, the way is open for a possible physics run with proton-lead collisions in 2012.   Members of the LHC team photographed when the first hybrid beams got to full energy. The proton and lead beams are visible on the leftmost screen up on the wall (click to enlarge the photo). The technical challenge of making different beams circulate in the LHC is by no means trivial. Even if the machine is the same, there are a number of differences when it is operated with beams of protons, beams of lead or beams of proton and lead. Provided that the beams are equal, irrespective of whether they consist of protons or lead nuclei, they revolve at the...

  20. ATLAS diamond Beam Condition Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Gorisek, A. [CERN (Switzerland)]. E-mail: andrej.gorisek@cern.ch; Cindro, V. [J. Stefan Institute (Slovenia); Dolenc, I. [J. Stefan Institute (Slovenia); Frais-Koelbl, H. [Fotec (Austria); Griesmayer, E. [Fotec (Austria); Kagan, H. [Ohio State University, OH (United States); Korpar, S. [J. Stefan Institute (Slovenia); Kramberger, G. [J. Stefan Institute (Slovenia); Mandic, I. [J. Stefan Institute (Slovenia); Meyer, M. [CERN (Switzerland); Mikuz, M. [J. Stefan Institute (Slovenia); Pernegger, H. [CERN (Switzerland); Smith, S. [Ohio State University, OH (United States); Trischuk, W. [University of Toronto (Canada); Weilhammer, P. [CERN (Switzerland); Zavrtanik, M. [J. Stefan Institute (Slovenia)

    2007-03-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at z=+/-183.8cm. Timing of signals from the two stations will provide almost ideal separation of beam-beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of 1cm{sup 2} area and 500{mu}m thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test beam setup at KEK. Results from the test beams and bench measurements are presented.

  1. ATLAS diamond Beam Condition Monitor

    International Nuclear Information System (INIS)

    Gorisek, A.; Cindro, V.; Dolenc, I.; Frais-Koelbl, H.; Griesmayer, E.; Kagan, H.; Korpar, S.; Kramberger, G.; Mandic, I.; Meyer, M.; Mikuz, M.; Pernegger, H.; Smith, S.; Trischuk, W.; Weilhammer, P.; Zavrtanik, M.

    2007-01-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at z=+/-183.8cm. Timing of signals from the two stations will provide almost ideal separation of beam-beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of 1cm 2 area and 500μm thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test beam setup at KEK. Results from the test beams and bench measurements are presented

  2. Accident resistant transport container

    Science.gov (United States)

    Anderson, J.A.; Cole, K.K.

    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.

  3. Accident resistant transport container

    International Nuclear Information System (INIS)

    Andersen, J.A.; Cole, J.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

  4. Big nuclear accidents

    International Nuclear Information System (INIS)

    Marshall, W.; Billingon, D.E.; Cameron, R.F.; Curl, S.J.

    1983-09-01

    Much of the debate on the safety of nuclear power focuses on the large number of fatalities that could, in theory, be caused by extremely unlikely but just imaginable reactor accidents. This, along with the nuclear industry's inappropriate use of vocabulary during public debate, has given the general public a distorted impression of the risks of nuclear power. The paper reviews the way in which the probability and consequences of big nuclear accidents have been presented in the past and makes recommendations for the future, including the presentation of the long-term consequences of such accidents in terms of 'loss of life expectancy', 'increased chance of fatal cancer' and 'equivalent pattern of compulsory cigarette smoking'. The paper presents mathematical arguments, which show the derivation and validity of the proposed methods of presenting the consequences of imaginable big nuclear accidents. (author)

  5. Accidents in perspective

    International Nuclear Information System (INIS)

    Gittus, J.H.

    1989-01-01

    The nuclear industry perspective and the public perspective on big nuclear accidents and leukaemia near nuclear sites are discussed. The industry perspective is that big accidents are so unlikely as to be virtually impossible and that leukaemia is not specifically associated with nuclear installations. Clusters of cancer with statistical significance occur in major cities. The public perspective is coloured by a prejudice and myth: the fear of radiation. The big nuclear accident is seen therefore as much more unacceptable than any other big accident. Risks associated with Sizewell-B nuclear station and the liquid gas depot at Canvey Island are discussed. The facts and figures are presented as tables and graphs. Given conflicting interpretations of the leukaemia problem the public inclines towards the more pessimistic view. (author)

  6. 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...

  7. Occupational Accidents And Preventive Measures

    CERN Document Server

    Fassnacht, V

    2006-01-01

    This report presents the 2005 statistics concerning occupational accidents involving members of the CERN personnel and contractors' personnel. It sets out the accident frequency and severity rates and provides a breakdown of accidents by cause and injury. It also contains a summary analysis of the most serious accidents and the associated recommendations.

  8. 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...

  9. The Chernobyl accident

    International Nuclear Information System (INIS)

    Berg, J.O.; Christensen, G.; Lingjaerde, R.; Smidt Olsen, H.; Wethe, P.I.

    1986-10-01

    In connection with the Chernobyl accident the report gives a description of the technical features of importance to the accident, the course of events, and the estimated health hazards in the local environment. Dissimilarities in western and Sovjet reactor safety philosophy are dealt with, as well as conceivable concequences in relation to technology and research in western nuclear power programmes. Results of activity level measurements of air and foodstuff, made in Norway by Institute for Energy Technology, are given

  10. Accident and emergency management

    International Nuclear Information System (INIS)

    Andersen, V.; Moellenbach, K.; Heinonen, R.; Jakobsson, S.; Kukko, T.; Berg, Oe.; Larsen, J.S.; Westgaard, T.; Magnusson, B.; Andersson, H.; Holmstroem, C.; Brehmer, B.; Allard, R.

    1988-06-01

    There is an increasing potential for severe accidents as the industrial development tends towards large, centralised production units. In several industries this has led to the formation of large organisations which are prepared for accidents fighting and for emergency management. The functioning of these organisations critically depends upon efficient decision making and exchange of information. This project is aimed at securing and possibly improving the functionality and efficiency of the accident and emergency management by verifying, demonstrating, and validating the possible use of advanced information technology in the organisations mentioned above. With the nuclear industry in focus the project consists of five main activities: 1) The study and detailed analysis of accident and emergency scenarios based on records from incidents and rills in nuclear installations. 2) Development of a conceptual understanding of accident and emergency management with emphasis on distributed decision making, information flow, and control structure sthat are involved. 3) Development of a general experimental methodology for evaluating the effects of different kinds of decision aids and forms of organisation for emergency management systems with distributed decision making. 4) Development and test of a prototype system for a limited part of an accident and emergency organisation to demonstrate the potential use of computer and communication systems, data-base and knowledge base technology, and applications of expert systems and methods used in artificial intelligence. 5) Production of guidelines for the introduction of advanced information technology in the organisations based on evaluation and validation of the prototype system. (author)

  11. Accident management information needs

    International Nuclear Information System (INIS)

    Hanson, D.J.; Ward, L.W.; Nelson, W.R.; Meyer, O.R.

    1990-04-01

    In support of the US Nuclear Regulatory Commission (NRC) Accident Management Research Program, a methodology has been developed for identifying the plant information needs necessary for personnel involved in the management of an accident to diagnose that an accident is in progress, select and implement strategies to prevent or mitigate the accident, and monitor the effectiveness of these strategies. This report describes the methodology and presents an application of this methodology to a Pressurized Water Reactor (PWR) with a large dry containment. A risk-important severe accident sequence for a PWR is used to examine the capability of the existing measurements to supply the necessary information. The method includes an assessment of the effects of the sequence on the measurement availability including the effects of environmental conditions. The information needs and capabilities identified using this approach are also intended to form the basis for more comprehensive information needs assessment performed during the analyses and development of specific strategies for use in accident management prevention and mitigation. 3 refs., 16 figs., 7 tabs

  12. Accident management information needs

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, D.J.; Ward, L.W.; Nelson, W.R.; Meyer, O.R. (EG and G Idaho, Inc., Idaho Falls, ID (USA))

    1990-04-01

    In support of the US Nuclear Regulatory Commission (NRC) Accident Management Research Program, a methodology has been developed for identifying the plant information needs necessary for personnel involved in the management of an accident to diagnose that an accident is in progress, select and implement strategies to prevent or mitigate the accident, and monitor the effectiveness of these strategies. This report describes the methodology and presents an application of this methodology to a Pressurized Water Reactor (PWR) with a large dry containment. A risk-important severe accident sequence for a PWR is used to examine the capability of the existing measurements to supply the necessary information. The method includes an assessment of the effects of the sequence on the measurement availability including the effects of environmental conditions. The information needs and capabilities identified using this approach are also intended to form the basis for more comprehensive information needs assessment performed during the analyses and development of specific strategies for use in accident management prevention and mitigation. 3 refs., 16 figs., 7 tabs.

  13. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2013-11-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to this issue, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for the latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. In this report the database was revised by adding aircraft accidents in 2011 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2012 database for the latest 20 years from 1992 to 2011. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for the latest 20 years from 1992 to 2011 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2012 revised database for the latest 20 years from 1992 to 2011 shows the followings. The trend of the 2012 database changes little as compared to the last year's report. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. The number of commercial aircraft accidents is 4 for large fixed-wing aircraft, 58 for small fixed-wing aircraft, 5 for large bladed aircraft and 99 for small bladed aircraft. The relevant accidents

  14. Natural circulation under variable primary mass inventories at BETHSY facility

    International Nuclear Information System (INIS)

    Bazin, P.; Clement, P.; Deruaz, R.

    1989-01-01

    BETHSY is a high pressure integral test facility which models a 3 loop Framatome PWR with the intent of studying PWR accidents. The BETHSY programme includes both accident transients and tests under successive steady state conditions. So far, tests of the latter type have been especially devoted to situations where natural circulation takes place in the primary coolant system (PCS). Tests 4.1a and 4.1a TC, the results of which are introduced, deal with PCS natural circulation patterns and related heat transport mechanisms under two different core power levels (2 and 5% of nominal power), variable primary mass inventory (100% to 30-40% according to core power) and at two different steam generator liquid levels (standard value and 1 meter). (orig.)

  15. Historical aspects of radiation accidents

    International Nuclear Information System (INIS)

    Mettler, F.A. Jr.; Ricks, R.C.

    1990-01-01

    Radiation accidents are extremely rare events; however, the last two years have witnessed the largest radiation accidents in both the eastern and western hemispheres. It is the purpose of this chapter to review how radiation accidents are categorized, examine the temporal changes in frequency and severity, give illustrative examples of several types of radiation accidents, and finally, to describe the various registries for radiation accidents

  16. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  17. Lessons learned from accidents in industrial irradiation facilities

    International Nuclear Information System (INIS)

    1996-01-01

    Use of ionizing radiation in medicine, industry and research for technical development continues to increase throughout the world. One application with a high growth rate is irradiation suing high energy gamma photons and electron beams. There are currently more than 160 gamma irradiation facilities and over 600 electron beam facilities in operation in almost all IAEA Member States. The most common uses of these facilities are to sterilize medical and pharmaceutical products, to preserve foodstuffs, to synthesize polymers and to eradicate insects. Although this industry has a good safety record, there is a potential for accidents with serious consequences to human health because of the high dose rates produced by these sources. Fatal accidents have occurred at installations in both developed and developing countries. Such accidents have prompted a review of several accidents, including five with fatalities, by a team of manufacturers, regulatory authorities and operating organizations. Having looked closely at the circumstances of each accident and the apparent deficiencies in design, safety and regulatory systems and personnel performance, the team made a number of recommendations on the ways in which the safety of irradiators can be improved. The findings of extensive research pertaining to the lessons that can be learned from irradiator accidents are presented. This publication is intended for manufacturers, regulatory authorities and operating organizations dealing with industrial irradiators. It was drafted by J.E. Glen, United States Nuclear Regulatory Commission, United States of America, and P. Zuniga-Bello, Consejo Nacional de Ciencia y Technologia, Mexico

  18. Material relating to the Chernobyl accident submitted by Belarus

    International Nuclear Information System (INIS)

    1996-01-01

    This material contains attachments provided by the Resident Representative of Belarus to the IAEA, who has requested that it be circulated to member states in connection with the First International Conference of the European Commission, Belarus, the Russian Federation and Ukraine on the consequences of the Chernobyl Accident held in Minsk held from 18 to 22 March 1996. The paper discusses the environmental and health effect of the accident and efforts made to assess and rehabilitate the environmental consequences. One of the obvious effect presented is a significant increase in incidence of thyroid cancer in children and adolescents

  19. Analysis of SBO accident for a swimming pool reactor

    International Nuclear Information System (INIS)

    Wang Guimin; Li Weiwei; Li Ning; Guo Wenhui

    2015-01-01

    The RELAP5/MOD3.3 code was adopted to compute the SBO accident condition of a swimming pool reactor. The coolant flow reversal process was calculated, and the influence of parameters of the flow between the core leakage and components on the flow reversal in the SBO accident condition was analyzed. The calculated results show that in the situation the reactor loses all forced flow, the residual heat of the reactor can be removed by the natural circulation flow, and the fuel subassembly will not be damaged. (authors)

  20. 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).

  1. Accidents in nuclear ships

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    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 -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)

  2. Experimental investigation on natural circulation and air-injection enhanced circulation in a simple loop

    International Nuclear Information System (INIS)

    Walter Ambrosini; Nicola Forgione; Francesco Oriolo; Filippo Pellacani; Mariano Tarantino; Claudio Struckmann

    2005-01-01

    Full text of publication follows: Natural circulation represents an interesting phenomenon because of both the complex aspects characterising it and for the widespread application in industry. On the other hand, injection of a gas into a rising branch of a loop represents a means to establish or to enhance a circulation flow, as it occurs in the so-called 'air-lift' loops. Both natural circulation and gas-injection enhanced circulation are presently considered for cooling Accelerator Driven System (ADS) reactors. These are subcritical reactors in which the fission reaction chain is maintained by the injection of neutrons obtained by spallation reactions in a target through a high energy proton beam generated in an external accelerator. The capability of such reactors to be used as incinerators of long lived fission products makes them particularly interesting in the light of the closure of the nuclear fuel cycle. Some of the fluids proposed as coolants for these reactors are liquid metals, with main interest for lead and lead-bismuth eutectic (LBE). Experimental activities are being performed in support to the design of the reactor prototype by different organisations. The university of Pisa, in addition to provide cooperation in these large scale activities performed with LBE has set up a specific experimental program aimed at studying the fundamental mechanisms involved in natural circulation and gas-injection enhanced circulation. The adopted experimental facility consists in a simple loop, having a rectangular lay-out (roughly, 4 m tall and 1 m wide), equipped with a 5 kW, 1 m tall heater, a 2 m long pipe-in-pipe heat exchanger, an air injection device and a separator. The fluid adopted in the tests performed up to now is water, though studies for evaluating the feasibility of the adoption of different fluids have been undertaken. Experimental data reported in previous publications concerning this research were related to a relatively high range of gas

  3. The accident of overexposure at the University hospital center of Toulouse. Expertise report n.1. Checking of experimental protocols of micro-beams calibration before and after dysfunction correction

    International Nuclear Information System (INIS)

    2007-01-01

    The regional center of stereotaxic radiosurgery of the University hospital center of Toulouse is equipped since april 2006 of a Novalis accelerator (Brainlab) devoted to the intra-skull stereotaxic radiosurgery. In april 2007, during an intercomparison of dosimetry computer files coming from different sites, the Brainlab society finds an anomaly in the files. The analysis made by the society concludes to to the use of an inappropriate detector for the measurement of a dosimetry parameter during the initial calibration of the accelerator. following this error, 145 patients (on the 172 treated by the service in question) suffer the consequences of an overdose whom importance is variable according the cases. The I.R.S.N. in charge of an expertise about the protocols of calibration of micro-beams before and after the correction of the dysfunction, took up with the search of the technical causes of the dysfunction. This report presents successively: the documents base on which is founded the expertise; the material of dosimetry and quality control necessary to the initial calibration of the device and to its follow-up; the formula made at the accelerator commissioning; the calibration of micro-beams in the two configurations that allows the device (micro-multi-knives and conic collimator) and the definition of parameters of the software of treatment planning; the maintenance and quality control implemented in the frame of its clinical use. (N.C.)

  4. School accidents in Austria.

    Science.gov (United States)

    Schalamon, Johannes; Eberl, Robert; Ainoedhofer, Herwig; Singer, Georg; Spitzer, Peter; Mayr, Johannes; Schober, Peter H; Hoellwarth, Michael E

    2007-09-01

    The aim of this study was to obtain information about the mechanisms and types of injuries in school in Austria. Children between 0 and 18 years of age presenting with injuries at the trauma outpatient in the Department of Pediatric Surgery in Graz and six participating hospitals in Austria were evaluated over a 2-year prospective survey. A total of 28,983 pediatric trauma cases were registered. Personal data, site of the accident, circumstances and mechanisms of accident and the related diagnosis were evaluated. At the Department of Pediatric Surgery in Graz 21,582 questionnaires were completed, out of which 2,148 children had school accidents (10%). The remaining 7,401 questionnaires from peripheral hospitals included 890 school accidents (12%). The male/female ratio was 3:2. In general, sport injuries were a predominant cause of severe trauma (42% severe injuries), compared with other activities in and outside of the school building (26% severe injuries). Injuries during ball-sports contributed to 44% of severe injuries. The upper extremity was most frequently injured (34%), followed by lower extremity (32%), head and neck area (26%) and injuries to thorax and abdomen (8%). Half of all school related injuries occur in children between 10 and 13 years of age. There are typical gender related mechanisms of accident: Boys get frequently injured during soccer, violence, and collisions in and outside of the school building and during craft work. Girls have the highest risk of injuries at ball sports other than soccer.

  5. Arctic circulation regimes.

    Science.gov (United States)

    Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

    2015-10-13

    Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

  6. Polarised and tagged gamma-ray Ladon beams

    Energy Technology Data Exchange (ETDEWEB)

    Babusci, D [Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati

    1995-11-01

    The production of polarized and tagged gamma-ray beams by the backscattering of Laser light on the relativistic electrons circulating in storage rings is discussed. the main characteristic and the experimental results of the Ladon and LEGS beams are presented. The Graal beam is introduced.

  7. Polarised and tagged gamma-ray Ladon beams

    International Nuclear Information System (INIS)

    Babusci, D.

    1995-11-01

    The production of polarized and tagged gamma-ray beams by the backscattering of Laser light on the relativistic electrons circulating in storage rings is discussed. the main characteristic and the experimental results of the Ladon and LEGS beams are presented. The Graal beam is introduced

  8. Keynote on lessons from major radiation accidents

    International Nuclear Information System (INIS)

    Ortiz, P.; Oresegun, M.; Wheatley, J.

    2000-01-01

    Generic lessons have been learned from a relatively large number of accidents in the most relevant practices (a set of analysis have been made on about 90 radiotherapy events, 43 industrial radiography and nine from industrial irradiations); more specific lessons have been drawn from in-depth investigations of individual accidents. The body of knowledge is grouped as follows: a) radiotherapy is very unique in that humans (patients) are purposely given very high radiation doses (20-75 Gy) by placing them in the radiation beam or by placing radioactive sources in contact with tissues. Intended deterministic effects are the essence of the normal radiotherapy practice and relatively small deviation from the intended doses, i.e,, slightly higher or lower than intended may cause increased rate of severe complication or reduce probability of cure. Consequences of major accidents have been devastating, affecting tens, even hundreds of patients and causing death (directly or indirectly) to a large number of them; b) accidents involving industrial radiography are the most frequent cause of overexposure to workers (radiographers); c) accidents with industrial irradiators have lower probability of occurrence, however, they are deemed to be fatal, especially when whole body exposure to panoramic gamma irradiators occur; partial body irradiation from industrial or research accelerator beams has led to amputation of hands and legs; d) when control of sources was relinquished ('orphan' sources) this has resulted in severe injuries, in some cases death and widespread contamination of the environment. A tool for further dissemination of lessons will be an international reporting system of unusual radiation events (RADEV), being introduced world-wide. Accidents were rarely due to a single human error or isolated equipment failure. In most cases there was a combination of elements such as: a) unawareness of the potential for an accident, b) poor education, which usually did not

  9. Development of CO2 circulators

    International Nuclear Information System (INIS)

    Donaldson, J.

    1988-01-01

    The development of the basic machine types we have supplied has not been without problems. The Windscale AGR (the prototype AGR) was a small 1.2 MW vertically up circulator with an inlet temperature of 237 deg. C (459 deg. F). Oil leakage problems occurred and were cured in the works test facility and the machine went into service with no other problems. The Horizontal 5 MW machines for Hinkley/Hunterston were not so fortunate with vibration problems, interface corrosion problems (effecting the whole reactor) and material dimensional stability problems. Oil ingress problems did not show up in test work but were later reported from site. These reports were initially exagerated due to the measuring techniques which took the operators some time to resolve. In the vertical 5 MW machines for Hartlepool and Heysham 1 there are two interesting factors, firstly a spar failure and secondly shaft axial stability. Many of the problems were due to modifications at site or our inability to model all aspects of site installation from which lessons for the future can be learned. The latest stations Torness and Heysham II incorporate these lessons. The machines have been designed with so much margin that during the resolution of the reactor control rod gag problems the machines were run continuously at 20% overload (6.3 MW). From an initial accident case of 350 deg. C inlet temperature, this increased to 458 deg. C and now stands at 585 deg. C. No modifications to the impeller were required. The site experience to date is good with no operational problems reported. (author). 4 figs

  10. Radiation accidents and dosimetry

    International Nuclear Information System (INIS)

    Sagstuen, E.; Theisen, H.; Henriksten, T.

    1982-12-01

    On September 2nd 1982 one of the employees of the gamma-irradiation facility at Institute for Energy Technology, Kjeller, Norway entered the irradiation cell with a 65.7 kCi *sp60*Co- source in unshielded position. The victim received an unknown radiation dose and died after 13 days. Using electron spin resonance spectroscopy, the radiation dose in this accident was subsequently determined based on the production of longlived free radicals in nitroglycerol tablets borne by the operator during the accident. He used nitroglycerol for heart problems and free radical are easily formed and trapped in sugar which is the main component of the tablets. Calibration experiments were carried out and the dose given to the tablets during the accident was determined to 37.2 +- 0.5 Gy. The general use of free radicals for dose determinations is discussed. (Auth.)

  11. Big nuclear accidents

    International Nuclear Information System (INIS)

    Marshall, W.

    1983-01-01

    Much of the debate on the safety of nuclear power focuses on the large number of fatalities that could, in theory, be caused by extremely unlikely but imaginable reactor accidents. This, along with the nuclear industry's inappropriate use of vocabulary during public debate, has given the general public a distorted impression of the safety of nuclear power. The way in which the probability and consequences of big nuclear accidents have been presented in the past is reviewed and recommendations for the future are made including the presentation of the long-term consequences of such accidents in terms of 'reduction in life expectancy', 'increased chance of fatal cancer' and the equivalent pattern of compulsory cigarette smoking. (author)

  12. Care of radiation accidents

    International Nuclear Information System (INIS)

    Renz, K.

    1983-01-01

    The small probability of a serious radiation accident happening dispenses neither the plants where radiation exposure occurs nor the employers' liability insurance associations from their obligation to make provision for such cases. On the other hand, the efforts involved in such preventive measures must be kept within reasonable limits. As a result of these considerations a concept for taking care of radiation accidents was developed that is based on already existing institutions. The most attention was demanded by questions of organization, logistics, communication and information. The syndrome appearing after acute whole-body irradiation is known. This syndrome in its different stages and the relative therapeutic measures form the basis for the organization of the care of radiation accidents. (orig./MG) [de

  13. Review of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Connelly, J.W.; Storr, G.J.

    1989-01-01

    Two types of severe reactor accidents - loss of coolant or coolant flow and transient overpower (TOP) accidents - are described and compared. Accidents in research reactors are discussed. The 1961 SL1 accident in the US is used as an illustration as it incorporates the three features usually combined in a severe accident - a design flaw or flaws in the system, a circumvention of safety circuits or procedures, and gross operator error. The SL1 reactor, the reactivity accident and the following fuel-coolant interaction and steam explosion are reviewed. 3 figs

  14. Criticality accident alarm system

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1991-01-01

    The American National Standard ANSI/ANS-8.3-1986, Criticality Accident Alarm System provides guidance for the establishment and maintenance of an alarm system to initiate personnel evacuation in the event of inadvertent criticality. In addition to identifying the physical features of the components of the system, the characteristics of accidents of concern are carefully delineated. Unfortunately, this ANSI Standard has led to considerable confusion in interpretation, and there is evidence that the ''minimum accident of concern'' may not be appropriate. Furthermore, although intended as a guide, the provisions of the standard are being rigorously applied, sometimes with interpretations that are not consistent. Although the standard is clear in the use of absorbed dose in free air of 20 rad, at least one installation has interpreted the requirement to apply to dose in soft tissue. The standard is also clear in specifying the response to both neutrons and gamma rays. An assembly of uranyl fluoride enriched to 5% 235 U was operated to simulate a potential accident. The dose, delivered in a free run excursion 2 m from the surface of the vessel, was greater than 500 rad, without ever exceeding a rate of 20 rad/min, which is the set point for activating an alarm that meets the standard. The presence of an alarm system would not have prevented any of the five major accidents in chemical operations nor is it absolutely certain that the alarms were solely responsible for reducing personnel exposures following the accident. Nevertheless, criticality alarm systems are now the subject of great effort and expense. 13 refs

  15. Accident at Harrisburg

    International Nuclear Information System (INIS)

    1979-05-01

    The course of events during the accident on 28 March 1979 at Three Mile Island-2 Reactor at Harrisburg, Pennsylvania, is described in detail. The effects (in the environment and within the safety containment) are described. The following points are then discussed: the possibility of a comparable accident occurring in the nuclear power stations in the German Federal Republic; the possibility of any point having been overlooked in the design of nuclear power stations in the Federal Republic; whether previous risk analyses are still valid; and how near the Three Mile Island reactor was to a core meltdown. Some conclusions are drawn. (U.K.)

  16. Mortal radiological accident

    International Nuclear Information System (INIS)

    Gimenez, J.C.

    1987-01-01

    After defining the concept of 'Radiological accident', statistical data from Radiation Emergency Assistance Center of ORNL (United States of America) are given about the deaths caused by acute irradiation between 1944 and April 24, 1986 -ie, the day before Chernobyl nuclear accident- as well as on the number of deaths caused by the latter. Next the different clinical stages of the Acute Irradiation Syndrome (AIS) as well as its possible treatment are described, and finally the different physical, clinical and biological characteristics linked to the AIS and to its diagnosis and prognosis are discussed. (M.E.L.) [es

  17. The TMI-2 accident

    International Nuclear Information System (INIS)

    Loureiro, L.A.

    1986-01-01

    A critical study about the technical and man-related facts in order to establish what is considered the worst commercial nuclear power accident until 1986. Radiological consequences and stress to the public are considered in contrast to antinuclear groups. This descriptive and technical study has the purpose to document written and oral opinions obtained abroad and then explain to the public in an easy language terminology. Preliminary study describing safety related systems fails and the accident itself with minute to minute description, conduct to the consequences and then, to learned lessons

  18. Domino effect in chemical accidents: main features and accident sequences.

    Science.gov (United States)

    Darbra, R M; Palacios, Adriana; Casal, Joaquim

    2010-11-15

    The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident scenario, the type of accident, the materials involved, the causes and consequences and the most common accident sequences. The analysis showed that the most frequent causes are external events (31%) and mechanical failure (29%). Storage areas (35%) and process plants (28%) are by far the most common settings for domino accidents. Eighty-nine per cent of the accidents involved flammable materials, the most frequent of which was LPG. The domino effect sequences were analyzed using relative probability event trees. The most frequent sequences were explosion→fire (27.6%), fire→explosion (27.5%) and fire→fire (17.8%). Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Electron beam irradiating device

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, K

    1969-12-20

    The efficiency of an electron beam irradiating device is heightened by improving the irradiation atmosphere and the method of cooling the irradiation window. An irradiation chamber one side of which incorporates the irradiation windows provided at the lower end of the scanner is surrounded by a suitable cooling system such as a coolant piping network so as to cool the interior of the chamber which is provided with circulating means at each corner to circulate and thus cool an inert gas charged therewithin. The inert gas, chosen from a group of such gases which will not deleteriously react with the irradiating equipment, forms a flowing stream across the irradiation window to effect its cooling and does not contaminate the vacuum exhaust system or oxidize the filament when penetrating the equipment through any holes which the foil at the irradiation window may incur during the irradiating procedure.

  20. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-09-11

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  1. Passive decay heat removal by natural circulation

    International Nuclear Information System (INIS)

    Vijayan, P.K.; Venkat Raj, V.; Kakodkar, A.; Mehta, S.K.

    1990-01-01

    The standardised 235 MWe PHWRs being built in India are the pressure tube type, heavy water moderated, heavy water cooled and natural uranium fuelled reactors. Several passive safety features are incorporated in these reactors. These include: (1) Containment pressure reduction and fission product trapping with the help of suppression pool following LOCA. (2) Emergency coolant injection by means of accumulators. (3) Large heat sink provided by the low temperature moderator under accident conditions. (4) Low excess reactivity, through the use of natural uranium fuel and on power fuelling. (5) Residual heat removal by means of natural circulation, etc. of which the last item is the subject matter of this report. (author). 8 refs, 10 figs

  2. Controlled humidity gas circulators

    International Nuclear Information System (INIS)

    Gruner, S.M.

    1981-01-01

    A programmable circulator capable of regulating the humidity of a gas stream over a wide range of humidity is described. An optical dew-point hygrometer is used as a feedback element to control the addition or removal of water vapor. Typical regulation of the gas is to a dew-point temperature of +- 0.2 0 C and to an accuracy limited by the dew-point hygrometer

  3. Fluid circulation control device

    International Nuclear Information System (INIS)

    Benard, Henri; Henocque, Jean.

    1982-01-01

    Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

  4. [Drugs and occupational accident].

    Science.gov (United States)

    Bratzke, H; Albers, C

    1996-02-01

    In a case of a fatal occupational accident (construction worker, fall from roof, urine test positive for cocaine and THC, e.g. cannabis) the question arised to what extent those drug-related occupational accidents occur. In the literature only few cases, mainly dealing with cannabis influence, have been reported, however, a higher number is suspected. Cocaine and other stimulating drugs (amphetamine) are more often used to increase physical fitness. By direct or indirect interference with vigilance these compounds may provoke accidents. Due to the lack of a legal basis proving of the influence of drugs at the working place is still very limited, although highly sensitive chemical-toxicological assay procedures are available to detect even the chronic abuse (in hair). In the general conditions of accident insurances a compensation is excluded when alcohol is involved, but drugs are not mentioned. It is indeed difficult to establish a concentration limit for drugs like that existing for alcohol (1.1%). In each case the assay of the drug involved and exact knowledge of its specific effects is in an essential prerequisite to prove the causal relationship.

  5. Note nuclear accidents combat

    International Nuclear Information System (INIS)

    1989-01-01

    In this document the starting points are described which underlie the new framework for the nuclear-accident combat in the Netherlands. All the elaboration of this is indicated in main lines. The juridical consequences of the proposed structure are enlightened and the sequel activities are indicated. (H.W.). 6 figs.; 8 tabs

  6. Measures against nuclear accidents

    International Nuclear Information System (INIS)

    1992-01-01

    A select committee appointed by the Norwegian Ministry of Social Affairs put forward proposals concerning measures for the improvement of radiation protection preparedness in Norway. On the basis on an assessment of the potential radiation accident threat, the report examines the process of response, and identifies the organizational and management factors that influence that process

  7. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    1986-01-01

    The documentation abstracted contains a complete survey of the broadcasts transmitted by the Russian wire service of the Deutsche Welle radio station between April 28 and Mai 15, 1986 on the occasion of the Chernobyl reactor accident. Access is given to extracts of the remarkable eastern and western echoes on the broadcasts of the Deutsche Welle. (HP) [de

  8. First beam splashes at the LHC

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    After a two-year shutdown, the first beams of Run 2 circulated in the LHC last Sunday. On Tuesday, the LHC operators performed dedicated runs to allow some of the experiments to record their first signals coming from particles splashed out when the circulating beams hit the collimators. Powerful reconstruction software then transforms the electronic signals into colourful images.     “Splash” events are used by the experiments to test their numerous subdetectors and to synchronise them with the LHC clock. These events are recorded when the path of particles travelling in the LHC vacuum pipe is intentionally obstructed using collimators – one-metre-long graphite or tungsten jaws that are also used to catch particles that wander too far from the beam centre and to protect the accelerator against unavoidable regular and irregular beam losses. The particles sprayed out of the collision between the beam and the collimators are mostly muons. ATLAS and CMS&...

  9. Analysis of a postulated accident scenario involving loss of forced flow in a LMFBR

    International Nuclear Information System (INIS)

    Moreira, M.L.

    1985-01-01

    A model to analyse a postulated accident scenario involving loss of forced flow in the reactor vessel of a LMFBR is used. Five phases of the accident are analysed: Natural Circulation, Subcooled Boiling, Nucleate Boiling, Core Dryout and Cladding melt. The heat conduction in the fuel cladding, coolant and lower and upper plenum are calculated by a lump-parameter model. Physical data of a prototype LMFBR reactor were used for the calculation. (author)

  10. 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)

  11. Overview of core disruptive accidents

    International Nuclear Information System (INIS)

    Marchaterre, J.F.

    1977-01-01

    An overview of the analysis of core-disruptive accidents is given. These analyses are for the purpose of understanding and predicting fast reactor behavior in severe low probability accident conditions, to establish the consequences of such conditions and to provide a basis for evaluating consequence limiting design features. The methods are used to analyze core-disruptive accidents from initiating event to complete core disruption, the effects of the accident on reactor structures and the resulting radiological consequences are described

  12. Lessons learned from accident investigations

    International Nuclear Information System (INIS)

    Zuniga-Bello, P.; Croft, J.R.; Glenn, J.

    1998-01-01

    Accidents in 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 from them. A brief description of some of these accidents is given. Lessons learned from the accidents described are approached bearing in mind: safety culture, quality assurance, human factors, good engineering practice, defence in depth, security of sources, safety assessment and monitoring and verification compliance. (author)

  13. Beam loading

    OpenAIRE

    Boussard, Daniel

    1987-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superco...

  14. Molecular beams

    International Nuclear Information System (INIS)

    Pendelbury, J.M.; Smith, K.F.

    1987-01-01

    Studies with directed collision-free beams of particles continue to play an important role in the development of modern physics and chemistry. The deflections suffered by such beams as they pass through electric and magnetic fields or laser radiation provide some of the most direct information about the individual constituents of the beam; the scattering observed when two beams intersect yields important data about the intermolecular forces responsible for the scattering. (author)

  15. EPRI research on accident management

    International Nuclear Information System (INIS)

    Oehlberg, R.N.; Chao, J.

    1991-01-01

    The paper discusses Nuclear Regulatory Commission (NRC) efforts regarding severe reactor accident management and the Nuclear Management and Resources Council (NUMAEX), activities. (EPRI) Electric Power Research Institute accident management program consists of the two products just mentioned plus one related to severe accident plant status information and the MAAP 4.0 computer code. These are briefly discussed

  16. Accident management on french PWRS

    International Nuclear Information System (INIS)

    Queniart, D.

    1990-06-01

    After a brief recall of French safety rationale, the reactor operation and severe accident management is given. The research and development aimed at developing accident management procedures and emergency organization in France for the case of a NPP accident are also given

  17. Casebook on electric safety accidents

    International Nuclear Information System (INIS)

    1987-09-01

    This book gives concentration on electric safety accidents in domestic and abroad, which introduces general electrical safety with property of electricity, safe equipment and maintenance and protection of electric shock. It lists the cases of accident caused of electricity in domestic like accident in power substation, utilization equipment, load system and another accident by electricity like death in electric shock another by electricity like death in electric shock in new building construction, the cases caused of electricity in abroad like damage in electric shock by high voltage electric transformer, electric shock in summer and earth fault accident by fault cooling tower.

  18. Radiological accidents balance in medicine

    International Nuclear Information System (INIS)

    Nenot, J.C.

    1995-01-01

    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

  19. Use of off-axis injection as an alternative to geometrically merging beams in an energy-recovering linac

    Science.gov (United States)

    Douglas, David R [York County, VA

    2012-01-10

    A method of using off-axis particle beam injection in energy-recovering linear accelerators that increases operational efficiency while eliminating the need to merge the high energy re-circulating beam with an injected low energy beam. In this arrangement, the high energy re-circulating beam and the low energy beam are manipulated such that they are within a predetermined distance from one another and then the two immerged beams are injected into the linac and propagated through the system. The configuration permits injection without geometric beam merging as well as decelerated beam extraction without the use of typical beamline elements.

  20. A beam scraper using a linear motor

    International Nuclear Information System (INIS)

    Beadle, E.R.; Rodger, E.S.; Thern, R.E.

    1989-01-01

    A beam scraper using a linear motor drive has been developed for use in the AGS at Brookhaven National Laboratory. The device is used to measure beam size by moving a target to a predetermined location and measuring the intercepted beam with nearby loss monitors or by noting the decrease in the circulating beam current. This device has excellent vacuum characteristics, as the motor and sensor coils are outside the vacuum, coupled magnetically to the moving parts which, are inside. There are no bellows or dynamic seals required. The position-time profile is controlled by a closed-loop servo system which uses position feedback. 2 refs., 4 figs

  1. Beam diagnostics

    International Nuclear Information System (INIS)

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-01-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the open-quotes Boosterclose quotes and open-quotes ATLASclose quotes linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates

  2. Analysis of accident caused by temperature increase at the RA reactor in Vinca

    International Nuclear Information System (INIS)

    Afgan, N; Kulundzic, P.

    1964-06-01

    The objective of this work was to determine the maximum time interval without accident due to mechanical failures. The following accidents caused by mechanical failures are taken into account: loss of moderator flow, moderator leaking with or without circulation, and accidents caused by removal of fuel channels from the reactor vessel. Obtained numerical and experimental results are presented. Experimental device installed at the reactor was used for verification of calculation results. The analysis was done for the most damaging conditions and thus the obtained results represent the lowest boundary values [sr

  3. Development of Accident Scenarios and Quantification Methodology for RAON Accelerator

    International Nuclear Information System (INIS)

    Lee, Yongjin; Jae, Moosung

    2014-01-01

    The RIsp (Rare Isotope Science Project) plans to provide neutron-rich isotopes (RIs) and stable heavy ion beams. The accelerator is defined as radiation production system according to Nuclear Safety Law. Therefore, it needs strict operate procedures and safety assurance to prevent radiation exposure. In order to satisfy this condition, there is a need for evaluating potential risk of accelerator from the design stage itself. Though some of PSA researches have been conducted for accelerator, most of them focus on not general accident sequence but simple explanation of accident. In this paper, general accident scenarios are developed by Event Tree and deduce new quantification methodology of Event Tree. In this study, some initial events, which may occur in the accelerator, are selected. Using selected initial events, the accident scenarios of accelerator facility are developed with Event Tree. These results can be used as basic data of the accelerator for future risk assessments. After analyzing the probability of each heading, it is possible to conduct quantification and evaluate the significance of the accident result. If there is a development of the accident scenario for external events, risk assessment of entire accelerator facility will be completed. To reduce the uncertainty of the Event Tree, it is possible to produce a reliable data via the presented quantification techniques

  4. ATLAS diamond Beam Condition Monitor

    CERN Document Server

    Gorišek, A; Dolenc, I; Frais-Kölbl, H; Griesmayer, E; Kagan, H; Korpar, S; Kramberger, G; Mandic, I; Meyer, M; Mikuz, M; Pernegger, H; Smith, S; Trischuk, W; Weilhammer, P; Zavrtanik, M

    2007-01-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at . Timing of signals from the two stations will provide almost ideal separation of beam–beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of area and thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test bea...

  5. Three Mile Island accident

    International Nuclear Information System (INIS)

    Barre, B.; Olivier, E.; Roux, J.P.; Pelle, P.

    2010-01-01

    Deluded by equivocal instrumentation signals, operators at TMI-2 (Three Mile Island - unit 2) misunderstood what was going on in the reactor and for 2 hours were taking inadequate decisions that turned a reactor incident into a major nuclear event that led to the melting of about one third of the core. The TMI accident had worldwide impacts in the domain of nuclear safety. The main consequences in France were: 1) the introduction of the major accident approach and the reinforcement of crisis management; 2) the improvement of the reactor design, particularly that of the pressurizer valves; 3) the implementation of safety probabilistic studies; 4) a better taking into account of the feedback experience in reactor operations; and 5) a better taking into account of the humane factor in reactor safety. (A.C.)

  6. The ultimate nuclear accident

    International Nuclear Information System (INIS)

    Abdus Salam, A.

    1988-01-01

    The estimated energy equivalent of Chernobyl explosion was the 1/150 th of the explosive energy equivalent of atomic bomb dropped on Hiroshima; while the devastation that could be caused by the world's stock pile of nuclear weapons, could be equivalent to 160 millions of Chernobyl-like incidents. As known, the number of nuclear weapons is over 50,000 and 2000 nuclear weapons are sufficient to destroy the world. The Three Mile Island and Chernobyl accidents have been blamed on human factors but also the human element, particularly in the form of psychological stresses on those operating the nuclear weapons, could accidentally bring the world to a nuclear catastrophe. This opinion is encouraged by the London's Sunday Times magazine which gave a graphic description of life inside a nuclear submarine. So, to speak of nuclear reactor accidents and not of nuclear weapons is false security. (author)

  7. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Malinauskas, A.P.; Buchanan, J.R.; Lorenz, R.A.; Yamashita, T.

    1986-01-01

    On April 26, 1986, an explosion occurred at the newest of four operating nuclear reactors at the Chernobyl site in the USSR. The accident initiated an international technical exchange of almost unprecedented magnitude; this exchange was climaxed with a meeting at the International Atomic Energy Agency in Vienna during the week of August 25, 1986. The meeting was attended by more than 540 official representatives from 51 countries and 20 international organizations. Information gleaned from that technical exchange is presented in this report. A description of the Chernobyl reactor, which differs significantly from commercial US reactors, is presented, the accident scenario advanced by the Russian delegation is discussed, and observations that have been made concerning fission product release are described

  8. Nuclear ship accidents

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1993-05-01

    In this report available information on 28 nuclear ship accident and incidents is considered. Of these 5 deals with U.S. ships and 23 with USSR ships. The ships are in almost all cases nuclear submarines. Only events that involve the nuclear propulsion plants, radiation exposures, fires/explosions and sea water leaks into the submarines are considered. Comments are made on each of the events, and at the end of the report an attempt is made to point out the weaknesses of the submarine designs which have resulted in the accidents. It is emphasized that much of the available information is of a rather dubious nature. consequently some of the assessments made may not be correct. (au)

  9. The Fukushima accident

    International Nuclear Information System (INIS)

    Maqua, M.; Stueck, R.

    2012-01-01

    On 11 March 2011, the Tohoku earthquake and the subsequent tsunami hit the Japanese east coast, causing more than 15,000 fatalities. To this date, 3,000 people are still missing. The Fukushima Dai-ichi NPP was the nuclear installation that was most affected by the tsunami. The earthquake cut off the NPP from the national grid. About 45 minutes later, the tsunami flooded units 1-4 and led to core meltdown events with large releases for units 1, 2 and 3. Unit 4 had been in refuelling outage at that time and lost the cooling of the spent fuel pool for several days. Considerable hydrogen explosions occurred in units 1, 3 and 4. Shortly after the accident, TEPCO started to mitigate the consequences of the accident by providing external cooling to the reactors and by removing the radioactive debris from the site. Great emphasis was laid on effective radiation protection measures for the clean-up workers. Thus, up to now there has been no fatality due to the radiation caused by the Fukushima accident. The main steps of the accident sequences are described, taking into account the latest findings of investigations performed by TEPCO or on behalf of the regulatory body. The presentation focuses on the description of the status of the Fukushima Dai-ichi nuclear power plant and the future steps for cleaning-up the site. In the presentation, the major phases of the roadmap that TEPCO has developed for the clean-up are highlighted. The risks associated with the current plant status and the clean-up phases are described. Abstract the content of the manuscript in a few lines.

  10. Severe accident management guidelines

    International Nuclear Information System (INIS)

    Uhle, Jennifer

    2014-01-01

    The events at Fukushima Daiichi have highlighted the importance of Severe Accident Management Guidelines (SAMGs). As the world has learned from the catastrophe and countries are considering changes to their nuclear regulatory programs, the content of SAMGs and their regulatory control are being evaluated. This presentation highlights several factors that are being addressed in the United States as rulemaking is underway pertaining to SAMGs. The question of how to be prepared for the unexpected is discussed with specific insights gleaned from Fukushima. (author)

  11. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Rassow, J.

    1986-01-01

    The documentation aims at giving a clearly arranged account of facts, interrelations and comparative evaluations of general interest. It deals with the course of events, atmospheric dispersion and fallout of the substances released and discusses the basic principles of the metering of radioactive radiation, the calculation of body doses and comparative evaluations with the radioactive exposure and risks involved by other sources. The author intends to contribute to an objective discussion about the Chernobyl reactor accident and nuclear energy as such. (DG) [de

  12. Radiation accident in Vietnam

    International Nuclear Information System (INIS)

    Wheatley, J.

    1994-01-01

    In November 1992 a Vietnamese research physicist was working with a microtron accelerator when he received a radiation overexposure that required the subsequent amputation of his right hand. A team from the International Atomic Energy Agency visited Hanoi in March 1993 to carry out an investigation. It was concluded that the accident occurred primarily because of a lack of safety systems, although the lack of both written procedures and training in basic radiation safety were also major contributors. (author)

  13. Impact of the TMI accident on the French nuclear program and the safety analysis

    International Nuclear Information System (INIS)

    Fourest, B.; Boaretto, Y.; Cayol, A.; Droulers, Y.; Goudal, M.; Oury, J.M.

    1980-04-01

    Almost immediately after the TMI accident, Electricite de France (EdF), Framatome and the French safety authorities started a large scale program of actions designed to analyse and understand the causes of the accident, and draw lessons applicable in France. This paper discusses these actions and the main conclusions of TMI accident analysis in France, notably: the fundamental role of plant operators, and the importance of operator training, written instructions and procedures, and diagnostic aids; the importance of feeding back operating experience to design teams, and incorporating the results of accident and post-accident studies in operating procedures; the necessity to improve knowledge of core cooling modes, including during two-phase flow and natural circulation; measures to improve particular systems and components [fr

  14. 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.

  15. Radiological accident of Goiania

    International Nuclear Information System (INIS)

    Palacios, Elias; Gimenez, J.C.

    1988-01-01

    The accident of Goiania that took place in September, 1987, was the consequence of the dismantlement of the teletherapy equipment containing a Cs 137 source. The activity of the source was of about 5,2.10 13 Bq(1.400 Ci) and was made up by 1.10 -1 Kg of ClCs. This is one of the worst accidents, involving medical or industrial source, which happened up to the moment. The accident and the criteria adopted to face the emergency are described. The characteristics of the irradiation and superficial and internal contamination of the persons affected caused any dosimetric evaluation to be particularly difficult. The emergency control managed by capable persons was carried out with the expected difficulties in some areas within the Goiania city. About 90 % of the material could be recovered, in the removal works, in order to be treated as radioactive waste. Conclusions that should be taken into account in Argentina are reached. The authors of the article took part in the emergency by helping the brazilian Authorities within the Mutual Assistance Agreement between Argentina and Braxil. (M.E.L.) [es

  16. Thule accident 1968

    International Nuclear Information System (INIS)

    Melgaard, L.; Moeller Kristensen, H.

    1987-01-01

    On January 21, 1968 an American B-52 bomber crashed on the ice at Thule in Nothern Greenland. The bomber carried 4 nuclear weapons that were destroyed. The radioactive material of the bombs was spread over a large area of the ice. About 850 Danes stayed at the Thule base in 1968 for a shorter or longer period. Out of these 850 probably between 70 and 170 men took part in the clearing after the accident. Danish and American authorities establised that the radioactive contamination from the accident was too small to cause any health effects. For that reason the Danish authorities did not follow the Danish workers in order to show late effects, if any. In defiance of the authorities' very cocksure attitude towards possible late effets parts of the Danish press in the Summer 1986 started to be interested in the matter and to search for previous Thule-workers. Up till January 1987 aboput 600 workers have been contacted by the press, trade unions, and private persons. About 500 out of the 600 workers report on illness, cancers and deaths. This report tries to compile the accessible informations on the matter, to descibe the possible radioactive and chemical effects, to compare the Thule accident with a similar incident in Spain in 1966, and to propose a comprehensive health examination of all the workers. (LN)

  17. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1997-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  18. Predisposing factors in posterior circulation infarcts: a vascular morphological assessment

    Energy Technology Data Exchange (ETDEWEB)

    Coban, Goekcen; Cifci, Egemen; Yildirim, Erkan; Agildere, Ahmet Muhtesem [Baskent University Faculty of Medicine, Department of Radiology, Konya (Turkey)

    2015-05-01

    The aim of the study is to assess the effect of shape, diameter, elongation and deviation criteria of basilar artery (BA), convergence angle and diameter variations of vertebral arteries, and concurrent chronic diseases on posterior circulation infarcts. Between January 2010 and May 2013, 186 patients who underwent brain and diffusion magnetic resonance imaging (MRI) with suspected cerebrovascular accident and were diagnosed with posterior circulation infarct and 120 infarct negative control subjects were included in this case-control retrospective study. Vertebral artery (VA) and BA diameter, right (R) and left (L) VA angles at the level of bifurcation, and BA elongation-deviation, and shape of BA were assessed in a total of 306 subjects. Ischemic lesions in the posterior circulation were classified according to their anatomical location and vascular perfusion areas. No significant difference was noted between the control and patient groups with respect to BA diameter (p = 0.676). The most effective risk factors for posterior circulation infarcts were as follows: BA elongation of 2 or 3, BA transverse location of 2 or 3, increase in left VA angle, and history of hypertension, hypercholesterolemia, and diabetes mellitus. Our results suggest that prominent elongation and deviation, C and J shape of BA, and increased L VA angle may be the predictors of at-risk patients in posterior circulation infarcts. Reporting marked morphological BA and VA variations detected at routine brain MRI will aid in selection of patients. Timely detection and treatment of at-risk patients may be life-saving. (orig.)

  19. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  20. Predisposing factors in posterior circulation infarcts: a vascular morphological assessment

    International Nuclear Information System (INIS)

    Coban, Goekcen; Cifci, Egemen; Yildirim, Erkan; Agildere, Ahmet Muhtesem

    2015-01-01

    The aim of the study is to assess the effect of shape, diameter, elongation and deviation criteria of basilar artery (BA), convergence angle and diameter variations of vertebral arteries, and concurrent chronic diseases on posterior circulation infarcts. Between January 2010 and May 2013, 186 patients who underwent brain and diffusion magnetic resonance imaging (MRI) with suspected cerebrovascular accident and were diagnosed with posterior circulation infarct and 120 infarct negative control subjects were included in this case-control retrospective study. Vertebral artery (VA) and BA diameter, right (R) and left (L) VA angles at the level of bifurcation, and BA elongation-deviation, and shape of BA were assessed in a total of 306 subjects. Ischemic lesions in the posterior circulation were classified according to their anatomical location and vascular perfusion areas. No significant difference was noted between the control and patient groups with respect to BA diameter (p = 0.676). The most effective risk factors for posterior circulation infarcts were as follows: BA elongation of 2 or 3, BA transverse location of 2 or 3, increase in left VA angle, and history of hypertension, hypercholesterolemia, and diabetes mellitus. Our results suggest that prominent elongation and deviation, C and J shape of BA, and increased L VA angle may be the predictors of at-risk patients in posterior circulation infarcts. Reporting marked morphological BA and VA variations detected at routine brain MRI will aid in selection of patients. Timely detection and treatment of at-risk patients may be life-saving. (orig.)

  1. Predisposing factors in posterior circulation infarcts: a vascular morphological assessment.

    Science.gov (United States)

    Çoban, Gökçen; Çifçi, Egemen; Yildirim, Erkan; Ağıldere, Ahmet Muhteşem

    2015-05-01

    The aim of the study is to assess the effect of shape, diameter, elongation and deviation criteria of basilar artery (BA), convergence angle and diameter variations of vertebral arteries, and concurrent chronic diseases on posterior circulation infarcts. Between January 2010 and May 2013, 186 patients who underwent brain and diffusion magnetic resonance imaging (MRI) with suspected cerebrovascular accident and were diagnosed with posterior circulation infarct and 120 infarct negative control subjects were included in this case-control retrospective study. Vertebral artery (VA) and BA diameter, right (R) and left (L) VA angles at the level of bifurcation, and BA elongation-deviation, and shape of BA were assessed in a total of 306 subjects. Ischemic lesions in the posterior circulation were classified according to their anatomical location and vascular perfusion areas. No significant difference was noted between the control and patient groups with respect to BA diameter (p = 0.676). The most effective risk factors for posterior circulation infarcts were as follows: BA elongation of 2 or 3, BA transverse location of 2 or 3, increase in left VA angle, and history of hypertension, hypercholesterolemia, and diabetes mellitus. Our results suggest that prominent elongation and deviation, C and J shape of BA, and increased L VA angle may be the predictors of at-risk patients in posterior circulation infarcts. Reporting marked morphological BA and VA variations detected at routine brain MRI will aid in selection of patients. Timely detection and treatment of at-risk patients may be life-saving.

  2. Reevaluation of Kori Unit 4 Natural Circulation Test

    Energy Technology Data Exchange (ETDEWEB)

    Yassin, Nassir [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Woo, Sweng Woong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-10-15

    The simulation results showed that the natural circulation flow developed by density difference was capable of removing decay heat from the fuel rod. The maximum pellet centerline temperature of the hot channel showed large margin to the pellet melting temperature. The maximum coolant temperature in the hot channel was well below the saturation temperature. If steam generators provide heat sink to the primary coolant system and thus natural circulation is maintained, the integrity of the fuel in the core can be sustained with large margin. Passive cooling of reactor is inevitable in case of failures in forced cooling system such as loss of electric power for cooling pumps. Fukushima accident showed the importance of the passive core cooling. During the commissioning test of PWRs, natural circulation test is performed to demonstrate the passive core cooling by natural convection. The driving force for coolant flow is developed by the density deference along the loop multiplied by the gravitation. Using the data from 'natural circulation test' and 'RCS flow coast down test' of Kori Unit 4, fuel behavior was reevaluated by FRAPTRAN code. RCS natural circulation test of Kori Unit 4 was reevaluated by FRAPTYRAN simulation to study the fuel behavior during the flow coast down transient and at the equilibrium condition in which decay heat transport and RCS flow were stabilized.

  3. Radiology of liver circulation

    International Nuclear Information System (INIS)

    Hermine, C.L.

    1985-01-01

    This book proposes that careful evaluation of the arterioportogram is the cornerstone in assessing portal flow obstruction, being the most consistent of all observations including liver histology, portal venous pressure, size and number of portosystemic collaterals, and wedged hepatic venous pressure. Very brief chapters cover normal hepatic circulation and angiographic methods. Contrast volumes and flow rates for celiac, hepatic, and superior mesenteric injection are given, with the timing for venous phase radiographs. In the main body of the text, portal obstruction is divided very simply into presinusoidal (all proximal causes) and postsinusoidal (all distal causes, including Budd-Chiari). Changes are discussed regarding the splenic artery and spleen; hepatic artery and its branches; portal flow rate and direction; and arterioportal shunting and portosystemic collateral circulation in minimal, moderate, severe, and very severe portal obstruction and in recognizable entities such as prehepatic portal and hepatic venous obstructions. The major emphasis in this section is the recognition and understanding of flow changes by which level and severity of obstruction are assessed (not simply the anatomy of portosystemic collateral venous flow). Excellent final chapters discuss the question of portal hypertension without obstruction, and the contribution of arterioportography to the treatment of portal hypertension, again with an emphasis on hemodynamics before and after shunt surgery. There is a fascinating final chapter on segmental intrahepatic obstruction without portal hypertension that explains much of the unusual contrast enhancement sometimes seen in CT scanning of hepatic mass lesions

  4. Circulation of Stars

    Science.gov (United States)

    Boitani, P.

    2016-01-01

    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  5. Accidents and human factors

    International Nuclear Information System (INIS)

    Nishiwaki, Y.; Kawai, H.; Morishima, H.; Terano, T.; Sugeno, M.

    1984-01-01

    When the TMI accident occurred it was 4 a.m., an hour when the error potential of the operators would have been very high. The frequency of car and train accidents in Japan is also highest between 4 a.m. and 6 a.m. The error potential may be classified into five phases corresponding to the electroencephalogramic pattern (EEG). At phase 0, when the delta wave appears, a person is unconscious and in deep sleep; at phase I, when the theta wave appears, he is very tired, sleepy and subnormal; at phase II, when the alpha wave appears, he is normal, relaxed and passive; at phase III, when the beta wave appears, he is normal, clear-minded and active; at phase IV, when the strong beta or epileptic wave appears, he is hypernormal, excited and incapable of normal judgement. Should an accident occur at phase II, the brain condition may jump to phase IV. At this phase the error or accident potential is maximum. The response of the human brain to different types of noises and signals may vary somewhat for different individuals and for different groups of people. Therefore, the possibility that such differences in brain functions may influence the mental structure would be worthy of consideration in human factors and in the design of man-machine systems. Human reliability and performance would be affected by many factors: medical, physiological and psychological, etc. The uncertainty involved in human factors may not necessarily be probabilistic, but fuzzy. Therefore, it would be important to develop a theory by which both non-probabilistic uncertainties, or fuzziness, of human factors and the probabilistic properties of machines can be treated consistently. From the mathematical point of view, probabilistic measure is considered a special case of fuzzy measure. Therefore, fuzzy set theory seems to be an effective tool for analysing man-machine systems. To minimize human error and the possibility of accidents, new safety systems should not only back up man and make up for his

  6. Radiation accident/disaster

    International Nuclear Information System (INIS)

    Kida, Yoshiko; Hirohashi, Nobuyuki; Tanigawa, Koichi

    2013-01-01

    Described are the course of medical measures following Fukushima Daiichi Nuclear Power Plant (FNPP) Accident after the quake and tsunami (Mar. 11, 2011) and the future task for radiation accident/disaster. By the first hydrogen explosion in FNPP (Mar. 12), evacuation of residents within 20 km zone was instructed, and the primary base for measures of nuclear disaster (Off-site Center) 5 km afar from FNPP had to work as a front base because of damage of communicating ways, of saving of injured persons and of elevation of dose. On Mar. 13, the medical arrangement council consisting from stuff of Fukushima Medical University (FMU), National Institute of Radiological Sciences, Nuclear Safety Research Association and Prefectural officers was setup in residents' hall of Fukushima City, and worked for correspondence to persons injured or exposed, where communication about radiation and between related organizations was still poor. The Off-site Center's head section moved to Prefectural Office on Mar. 15 as headquarters. Early in the period, all residents evacuated from the 20 km zone, and in-hospital patients and nursed elderly were transported with vehicles, >50 persons of whom reportedly died mainly by their base diseases. The nation system of medicare for emergent exposure had consisted from the network of the primary to third facilities; there were 5 facilities in the Prefecture, 3 of which were localized at 4-9 km distance from FNPP and closed early after the Accident; and the secondary facility of FMU became responsible to all exposed persons. There was no death of workers of FNPP. Medical stuff also measured the ambient dose at various places near FNPP, having had risk of exposure. At the Accident, the important system of command, control and communication was found fragile and measures hereafter should be planned on assumption of the worst scenario of complete damage of the infrastructure and communication. It is desirable for Disaster Medical Assistance Team which

  7. Survey of natural-circulation cooling in U.S. pressurized water reactors

    International Nuclear Information System (INIS)

    Boyack, B.E.

    1985-01-01

    Literature describing natural circulation analyses, experiments, and plant operation have been obtained from the Nuclear Regulatory Commission, reactor vendors, utility-sponsored research groups, utilities, national laboratories, and foreign sources. These have been reviewed and significant results and conclusions identified. Three modes of natural-circulation cooling are covered: single phase, two-phase, and reflux condensation. Single-phase natural circulation is amply verified by plant operational data, test data from scaled experimental facilities, and analysis with assessed computer codes. Ample evidence also exists that two-phase natural circulation can successfully cool pressurized water reactors. This mode occurs during certain events such as small-break loss-of-coolant accidents. The data base for reflux condensation is primarily from tests in scaled experimental facilities. There are no plant operational data and only limited assessment of thermal-hydraulic systems codes has been performed. Further work is needed before this mode of natural circulation can be confidently used

  8. Severe accident analysis methodology in support of accident management

    International Nuclear Information System (INIS)

    Boesmans, B.; Auglaire, M.; Snoeck, J.

    1997-01-01

    The author addresses the implementation at BELGATOM of a generic severe accident analysis methodology, which is intended to support strategic decisions and to provide quantitative information in support of severe accident management. The analysis methodology is based on a combination of severe accident code calculations, generic phenomenological information (experimental evidence from various test facilities regarding issues beyond present code capabilities) and detailed plant-specific technical information

  9. Beam loading

    CERN Document Server

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  10. Beam loading

    International Nuclear Information System (INIS)

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed. (author)

  11. Stress in accident and post-accident management at Chernobyl

    International Nuclear Information System (INIS)

    Girard, P.; Dubreuil, G.H.

    1996-01-01

    The effects of the Chernobyl nuclear accident on the psychology of the affected population have been much discussed. The psychological dimension has been advanced as a factor explaining the emergence, from 1990 onwards, of a post-accident crisis in the main CIS countries affected. This article presents the conclusions of a series of European studies, which focused on the consequences of the Chernobyl accident. These studies show that the psychological and social effects associated with the post-accident situation arise from the interdependency of a number of complex factors exerting a deleterious effect on the population. We shall first attempt to characterise the stress phenomena observed among the population affected by the accident. Secondly, we will be presenting an anlysis of the various factors that have contributed to the emerging psychological and social features of population reaction to the accident and in post-accident phases, while not neglecting the effects of the pre-accident situation on the target population. Thirdly, we shall devote some initial consideration to the conditions that might be conducive to better management of post-accident stress. In conclusion, we shall emphasise the need to restore confidence among the population generally. (Author)

  12. Circulation Systems Past and Present

    Directory of Open Access Journals (Sweden)

    Maurice J. Freedman

    1981-01-01

    Full Text Available A review of the development of circulation systems shows two areas of change. The librarian's perception of circulation control has shifted from a broad service orientation to a narrow record-keeping approach and recently back again. The technological development of circulation sys-tems has evolved from manual systems to the online systems of today. The trade-offs and deficiencies of earlier systems in relation to the comprehensive services made possible by the online computer are detailed.

  13. The ocean circulation inverse problem

    National Research Council Canada - National Science Library

    Wunsch, C

    1996-01-01

    .... This book addresses the problem of inferring the state of the ocean circulation, understanding it dynamically, and even forecasting it through a quantitative combination of theory and observation...

  14. Development of the APR1400 model for countercurrent natural circulation in hot leg and steam generator under station blackout

    International Nuclear Information System (INIS)

    Park, Sang Gil; Kim, Han Chul

    2012-01-01

    In order to analyze severe accident phenomena, Korea Institute of Nuclear Safety (KINS) made a MELCOR model for APR1400 to examine natural circulation and creep rupture failure in the Reactor Coolant System (RCS) under station blackout (SBO). In this study, we are trying to advance the former model to describe natural circulation more accurately. After Fukushima accident, the concerns of severe accident management, assuring the heat removal capability, has risen for the case when the SBO is happened and there are no more electric powers to cool down decay heat. Under SBO there are three kinds of natural circulation which can delay the core heatup. One is in vessel natural circulation in the upper plenum of reactor vessel and the second is countercurrent natural circulation in hot leg through steam generator tubes and the last is full loop natural circulation when the reactor coolant pump loop seal is cleared and reactor coolant pump sealing is damaged by high temperature and high pressure. Among them this study focuses on the countercurrent natural circulation model using MELCOR1.8.6

  15. Cernavoda CANDU severe accident evaluation

    International Nuclear Information System (INIS)

    Negut, G.; Marin, A.

    1997-01-01

    The papers present the activities dedicated to Romania Cernavoda Nuclear Power Plant first CANDU Unit severe accident evaluation. This activity is part of more general PSA assessment activities. CANDU specific safety features are calandria moderator and calandria vault water capabilities to remove the residual heat in the case of severe accidents, when the conventional heat sinks are no more available. Severe accidents evaluation, that is a deterministic thermal hydraulic analysis, assesses the accidents progression and gives the milestones when important events take place. This kind of assessment is important to evaluate to recovery time for the reactor operators that can lead to the accident mitigation. The Cernavoda CANDU unit is modeled for the of all heat sinks accident and results compared with the AECL CANDU 600 assessment. (orig.)

  16. 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...... aboard. Relative risks for notified accidents and accidents causing permanent disability of 5% or more were calculated in a multivariate analysis including ship type, occupation, age, time on board, change of ship since last employment period, and nationality. Foreigners had a considerably lower recorded...

  17. Accident management insights after the Fukushima Daiichi NPP accident

    International Nuclear Information System (INIS)

    Degueldre, Didier; Viktorov, Alexandre; Tuomainen, Minna; Ducamp, Francois; Chevalier, Sophie; Guigueno, Yves; Tasset, Daniel; Heinrich, Marcus; Schneider, Matthias; Funahashi, Toshihiro; Hotta, Akitoshi; Kajimoto, Mitsuhiro; Chung, Dae-Wook; Kuriene, Laima; Kozlova, Nadezhda; Zivko, Tomi; Aleza, Santiago; Jones, John; McHale, Jack; Nieh, Ho; Pascal, Ghislain; ); Nakoski, John; Neretin, Victor; Nezuka, Takayoshi; )

    2014-01-01

    The Fukushima Daiichi nuclear power plant (NPP) accident, that took place on 11 March 2011, initiated a significant number of activities at the national and international levels to reassess the safety of existing NPPs, evaluate the sufficiency of technical means and administrative measures available for emergency response, and develop recommendations for increasing the robustness of NPPs to withstand extreme external events and beyond design basis accidents. The OECD Nuclear Energy Agency (NEA) is working closely with its member and partner countries to examine the causes of the accident and to identify lessons learnt with a view to the appropriate follow-up actions to be taken by the nuclear safety community. Accident management is a priority area of work for the NEA to address lessons being learnt from the accident at the Fukushima Daiichi NPP following the recommendations of Committee on Nuclear Regulatory Activities (CNRA), Committee on the Safety of Nuclear Installations (CSNI), and Committee on Radiation Protection and Public Health (CRPPH). Considering the importance of these issues, the CNRA authorised the formation of a task group on accident management (TGAM) in June 2012 to review the regulatory framework for accident management following the Fukushima Daiichi NPP accident. The task group was requested to assess the NEA member countries needs and challenges in light of the accident from a regulatory point of view. The general objectives of the TGAM review were to consider: - enhancements of on-site accident management procedures and guidelines based on lessons learnt from the Fukushima Daiichi NPP accident; - decision-making and guiding principles in emergency situations; - guidance for instrumentation, equipment and supplies for addressing long-term aspects of accident management; - guidance and implementation when taking extreme measures for accident management. The report is built on the existing bases for capabilities to respond to design basis

  18. CANDU severe accident analysis

    International Nuclear Information System (INIS)

    Negut, Gheorghe; Catana, Alexandru; Prisecaru, Ilie; Dupleac, Daniel

    2007-01-01

    Romania is a EU member since January first 2007. This country faces now new challenges which imply also the nuclear power reactors now in operation. Romania operates since 1996 a CANDU nuclear power reactor and soon will start up a second unit. In EU PWR reactors are mostly operated, so that the Romania's reactors have to meet EU standards. Safety analysis guidelines require to model severe accidents for reactors of this type. Starting from previous studies a thermal-hydraulic model for a degraded CANDU core was developed. The initiating event is assumed to be a LOCA with simultaneous loss of moderator and coolant and the failure of emergency core cooling system (ECCS). This type of accident is likely to modify the reactor geometry and will lead to a severe accident development. When the coolant temperatures inside a pressure tube reaches 1000 deg. C, a contact between pressure tube and calandria tube occurs and the decay heat is transferred to the moderator. Due to the lack of cooling, the moderator eventually begins to boil and is expelled, through the calandria vessel relief ducts, into the containment. Therefore the calandria tubes (fuel channels) uncover, then disintegrate and fall down to the calandria vessel bottom. All the quantity of calandria moderator is vaporized and expelled, the debris will heat up and eventually boil. The heat accumulated in the molten debris will be transferred through the calandria vessel wall to the shield water tank surrounding the calandria vessel. The thermal hydraulics phenomena described above are modeled, analyzed and compared with the existing data. (authors)

  19. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    1986-05-01

    Following the accident at Chernobyl nuclear reactor, WHO organized on 6 May 1986 in Copenhagen a one day consultation of experts with knowledge in the fields of meteorology, radiation protection, biological effects, reactor technology, emergency procedures, public health and psychology in order to analyse the development of events and their consequences and to provide guidance as to the needs for immediate public health action. The present report provides detailed information on the transportation and dispersion of the radioactive material in the atmosphere, especially volatile elements, during the release period 26 April - 5 May. Presented are the calculated directions and locations of the radioactive plume over Europe in the first 5 days after the accident, submitted by the Swedish Meteorological and Hydrological Institute. The calculations have been made for two heights, 1500m and 750m and the plume directions are grouped into five periods, covering five European areas. The consequences of the accident inside the USSR and the radiological consequences outside the USSR are presented including the exposure routes and the biological effects, paying particular attention to iodine-131 effects. Summarized are the first reported measured exposure rates above background, iodine-131 deposition and concentrations in milk and the remedial actions taken in various European countries. Concerning the cesium-137 problem, based on the UNSCEAR assessment of the consequences of the nuclear fallout, one concludes that the cesium contamination outside the USSR is not likely to cause any serious problems. Finally, the conclusions and the recommendations of the meeting, taking into account both the short-term and longer term considerations are presented

  20. Traffic accidents: an econometric investigation

    OpenAIRE

    Tito Moreira; Adolfo Sachsida; Loureiro Paulo

    2004-01-01

    Based on a sample of drivers in Brasilia's streets, this article investigates whether distraction explains traffic accidents. A probit model is estimated to determine the predictive power of several variables on traffic accidents. The main conclusion drawn from this study is that the proxies used to measure distraction, such as the use of cell phones and cigarette smoking in a moving vehicle, are significant factors in determining traffic accidents.

  1. Medical aspects of radiation accidents

    International Nuclear Information System (INIS)

    Messerschmidt, O.

    1990-01-01

    Reactor accidents and nuclear bomb explosions are compared including the release of radioactivity in an accident, results of risk studies, emergency measures of nuclear power plants, and evacuation of the population. The medical aspects refer to the prophylaxies of the thyroid gland, contamination and decontamination of body surfaces, recommendations of the ICRP, radiation injury after total body exposure and medical problems after a reactor accident. (DG)

  2. Accident management approach in Armenia

    International Nuclear Information System (INIS)

    Ghazaryan, K.

    1999-01-01

    In this lecture the accident management approach in Armenian NPP (ANPP) Unit 2 is described. List of BDBAs had been developed by OKB Gydropress in 1994. 13 accident sequences were included in this list. The relevant analyses had been performed in VNIIAES and the 'Guidelines on operator actions for beyond design basis accident (BDBA) management at ANPP Unit 2' had been prepared. These instructions are discussed

  3. Simulation of Two-Phase Natural Circulation Loop for Core Cather Cooling Using Air Water

    International Nuclear Information System (INIS)

    Revankar, S. T.; Huang, S. F.; Song, K. W.; Rhee, B. W.; Park, R. J.; Song, J. H.

    2012-01-01

    A closed loop natural circulation system employs thermally induced density gradients in single phase or two-phase liquid form to induce circulation of the working fluid thereby obviating the need for any mechanical moving parts such as pumps and pump controls. This increases the reliability and safety of the cooling system and reduces installation, operation and maintenance costs. That is the reason natural circulation cooling has been considered in advanced reactor core cooling and in engineered safety systems. Natural circulation cooling has been proposed to remove reactor decay heat by external vessel cooling for in-vessel core retention during sever accident scenario. Recently in APR1400 reactor core catcher design natural circulation cooling is proposed to stabilize and cool the corium ejected from the reactor vessel following core melt and breach of reactor vessel. The natural circulation flow is similar to external vessel cooling where water flows through an inclined narrow gap below hot surface and is heated to produce boiling. The two-phase natural circulation enables cooling of the corium pool collected on core catcher. Due to importance of this problem this paper focuses simulation of the two-phase natural circulation through inclined gap using air-water system. Scaling criteria for air-water loop are derived that enable simulation of the flow regimes and natural circulation flow rates in such systems using air-water system

  4. Nuclear accidents and protection

    International Nuclear Information System (INIS)

    Biocanin, R.; Amidzic, B.

    2005-01-01

    The numerous threats are our cruel reality. There is a great arsenal of nuclear weapons. Nuclear terrorism and nuclear accidents are always possible, especially during the transport and handling different nuclear material. Terrorist organisation also goes for coming into the possession of the nuclear means. Specific and important problem is human radioactive contamination in using nuclear energy for peaceful and military purpose. So, realisation of the universal and united system of NBCD gives us a possibility by using the modern communication equipment and very effective mobile units to react in a real time and successfully perform monitoring, alarming, protection and decontamination. (author) [sr

  5. The accident of Chernobyl

    International Nuclear Information System (INIS)

    1986-10-01

    RBMK reactors (reactor control, protection systems, containment) and the nuclear power plant of Chernobyl are first presented. The scenario of the accident is given with a detailed chronology. The actions and consequences on the site are reviewed. This report then give the results of the source term estimation (fision product release, core inventory, trajectories, meteorological data...), the radioactivity measurements obtained in France. Health consequences for the French population are evoked. The medical consequences for the population who have received a high level of doses are reviewed [fr

  6. Psychological response of accident

    International Nuclear Information System (INIS)

    Novikov, V.S.; Nikiforov, A.M.; Cheprasov, V.Yu.

    1996-01-01

    The psychological status of rescuers of consequences of Chernobyl[s accidents, having planned stationary examination and treatment of common somatic diseases, has been examined. THe age of men represented the study group was 35-54 years old. The results of medical-psychological examination showed the development in rescuers of common dysadaptation and stress state, characterized by depressive-hypochondriac state with high anxiety. The course of psychotherapeutic activities made possible to improve essentionally the psychological status of the patients. 12 refs., 3 figs., 1 tab

  7. Reactor accident in Chernobyl

    International Nuclear Information System (INIS)

    Sokalski, A.; Kowalski, A.

    1990-11-01

    The bibliography contains 1568 descriptions of papers devoted to Chernobylsk accident and recorded in ''INIS Atomindex'' to 30 June 1990. The descriptions were taken from ''INIS Atomindex'' and are presented in accordance with volumes of this journal (chronology of recording). Therefore all descriptions have numbers showing first the number of volume and then the number of record. The bibliography has at the end the detailed subject index consisting of 465 main headings and a lot of qualifiers. Some of them are descriptors taken from ''INIS Atomindex'' and some are key words taken from natural language. The index is in English as descriptions in the bibliography. (author)

  8. Accident prevention programme

    International Nuclear Information System (INIS)

    1978-01-01

    This study by the Steel Industry Safety and Health Commission was made within the context of the application by undertakings of the principles of accident and disease prevention previously adopted by the said Commission. It puts forward recommendations for the effective and gradual implementation of a programme of action on occupational health and safety in the various departments of an undertaking and in the undertaking as a whole. The methods proposed in this study are likely to be of interest to all undertakings in the metallurgical industry and other industrial sectors

  9. Serious accident in Peru

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    A peruvian man, victim of an important accidental irradiation arrived on the Saturday twenty ninth of may 1999 to the centre of treatment of serious burns at the Percy military hospital (Clamart -France). The accident spent on the twentieth of February 1999, on the site of a hydroelectric power plant, in construction at 300 km at the East of Lima. The victim has picked up an industrial source of iridium devoted to gamma-graphy operations and put it in his back pocket; of trousers. The workman has serious radiation burns. (N.C.)

  10. Identicars: uno strumento per migliorare la resa testimoniale nelle indagini per omissione di soccorso stradale/Le système Identicars : un outil pour améliorer la qualité du témoignage dans les enquêtes pour le délit de fuite à la suite d’un accident de la circulation/Identicars system: a tool for improving the quality of witness in the investigations on hit-and-run driving accidents

    Directory of Open Access Journals (Sweden)

    Griggi Manuela

    2017-04-01

    witnesses of hit-and-run driving accidents to recognise the car in question. The researcher’s initial concept is that such a tool should help witnesses to provide more detailed and accurate descriptions. The authors will demonstrate the potential usefulness of the Identicars tool through the results achieved by an experiment carried out at the University of Bologna. These results show a greater accuracy of identification by those witnesses who used the Identicars tool in comparison to those who gave evidence using the traditional method for obtaining the information.

  11. Novel modular natural circulation BWR design and safety evaluation

    International Nuclear Information System (INIS)

    Ishii, Mamoru; Shi, Shanbin; Yang, Won Sik; Wu, Zeyun; Rassame, Somboon; Liu, Yang

    2015-01-01

    Highlights: • Introduction of BWR-type natural circulation small modular reactor preliminary design (NMR-50). • Design of long fuel cycle length for the NMR-50. • Design of double passive safety systems for the NMR-50. • RELAP5 analyses of design basis accidents for the NMR-50. - Abstract: The Purdue NMR (Novel Modular Reactor) represents a BWR-type small modular reactor with a significantly reduced reactor pressure vessel (RPV) height. Specifically, it has one third the height of a conventional BWR RPV with an electrical output of 50 MWe. The preliminary design of the NMR-50 including reactor, fuel cycle, and safety systems is described and discussed. The improved neutronics design of the NMR-50 extends the fuel cycle length up to 10 years. The NMR-50 is designed with double passive engineering safety system, which is intended to withstand a prolonged station black out with loss of ultimate heat sink accident such as experienced at Fukushima. In order to evaluate the safety features of the NMR-50, two representative design basis accidents, i.e. main steam line break (MSLB) and bottom drain line break (BDLB), are simulated by using the best-estimate thermal–hydraulic code RELAP5. The RPV water inventory, containment pressure, and the performance of engineering safety systems are investigated for about 33 h after the initiation of the accidents

  12. Superresolution beams

    CSIR Research Space (South Africa)

    Ngcobo, S

    2011-11-01

    Full Text Available The transformation of a Gaussian beam (GB) into a symmetrical higher order TEMp0 Laguerre Gaussian beam (LGB) intensity distribution of which is further rectified and transformed into a Gaussian intensity distribution in the plane of a converging...

  13. Credible investigation of air accidents

    International Nuclear Information System (INIS)

    Smart, K.

    2004-01-01

    Within the United Kingdom the Air Accidents Investigation Branch (AAIB) has been used as a model for the other transport modes accident investigation bodies. Government Ministers considered that the AAIB's approach had established the trust of the public and the aviation industry in its ability to conduct independent and objective investigations. The paper will examine the factors that are involved in establishing this trust. They include: the investigation framework; the actual and perceived independence of the accident investigating body; the aviation industry's safety culture; the qualities of the investigators and the quality of their liaison with bereaved families those directly affected by the accidents they investigate

  14. Guidance on accidents involving radioactivity

    International Nuclear Information System (INIS)

    1989-01-01

    This annex contains advice to Health Authorities on their response to accidents involving radioactivity. The guidance is in six parts:-(1) planning the response required to nuclear accidents overseas, (2) planning the response required to UK nuclear accidents a) emergency plans for nuclear installations b) nuclear powered satellites, (3) the handling of casualties contaminated with radioactive substances, (4) background information for dealing with queries from the public in the event of an accident, (5) the national arrangements for incident involving radioactivity (NAIR), (6) administrative arrangements. (author)

  15. 1976 Hanford americium accident

    International Nuclear Information System (INIS)

    Heid, K.R.; Breitenstein, B.D.; Palmer, H.E.; McMurray, B.J.; Wald, N.

    1979-01-01

    This report presents the 2.5-year medical course of a 64-year-old Hanford nuclear chemical operator who was involved in an accident in an americium recovery facility in August 1976. He was heavily externally contaminated with americium, sustained a substantial internal deposition of this isotope, and was burned with concentrated nitric acid and injured by flying debris about the face and neck. The medical care given the patient, including the decontamination efforts and clinical laboratory studies, are discussed. In-vivo measurements were used to estimate the dose rates and the accumulated doses to body organs. Urinary and fecal excreta were collected and analyzed for americium content. Interpretation of these data was complicated by the fact that the intake resulted both from inhalation and from solubilization of the americium embedded in facial tissues. A total of 1100 μCi was excreted in urine and feces during the first 2 years following the accident. The long-term use of diethylenetriaminepentate (DTPA), used principally as the zinc salt, is discussed including the method, route of administration, and effectiveness. To date, the patient has apparently experienced no complications attributable to this extensive course of therapy, even though he has been given approximately 560 grams of DTPA. 4 figures, 1 table

  16. Serious reactor accidents reconsidered

    International Nuclear Information System (INIS)

    1987-12-01

    The chance is determined for damage of the reactor core and that sequel events will cause excursion of radioactive materials into the environment. The gravity of such an accident is expressed by the source term. It appears that the chance for such an accident varies with the source term. In general it is valid that how larger the source term how smaller the chance is for it and vice versa. The chance for excursion is related to two complexes of events: serious damage (meltdown) of the reactor core, and the escape of the liberated radionuclides into the environment. The results are an order of magnitude consideration of the relation between the extent of the source term and the chance for it. From the spectrum of possible source terms three representative ones have been chosen: a large, a medium and a relative small source term. This choice is in accordance with international considerations. The hearth of this study is the estimation of the chance for occurrence of the three chosen source terms for new light-water reactors. refs.; figs.; tabs

  17. Assessment of accident energetics in LMFBR core-disruptive accidents

    International Nuclear Information System (INIS)

    Fauske, H.K.

    1977-01-01

    An assessment of accident energetics in LMFBR core-disruptive accidents is given with emphasis on the generic issues of energetic recriticality and energetic fuel-coolant interaction events. Application of a few general behavior principles to the oxide-fueled system suggests that such events are highly unlikely following a postulated core meltdown event

  18. Accident analysis. A review of the various accidents classifications

    International Nuclear Information System (INIS)

    Martin Martin, L.; Figueras, J.M.

    1982-01-01

    The objective of the accident analysis, in relation with the safety evaluation, environmental impact and emergency planning, should be to identify the total risk to the population and workers from potential accidents in the facility, analizing it over full spectrum of severity. (auth.)

  19. Interaction of vortices with flexible piezoelectric beams

    Science.gov (United States)

    Goushcha, Oleg; Akaydin, Huseyin Dogus; Elvin, Niell; Andreopoulos, Yiannis

    2012-11-01

    A cantilever piezoelectric beam immersed in a flow is used to harvest fluidic energy. Pressure distribution induced by naturally present vortices in a turbulent fluid flow can force the beam to oscillate producing electrical output. Maximizing the power output of such an electromechanical fluidic system is a challenge. In order to understand the behavior of the beam in a fluid flow where vortices of different scales are present, an experimental facility was set up to study the interaction of individual vortices with the beam. In our set up, vortex rings produced by an audio speaker travel at specific distances from the beam or impinge on it, with a frequency varied up to the natural frequency of the beam. Depending on this frequency both constructive and destructive interactions between the vortices and the beam are observed. Vortices traveling over the beam with a frequency multiple of the natural frequency of the beam cause the beam to resonate and larger deflection amplitudes are observed compared to excitation from a single vortex. PIV is used to compute the flow field and circulation of each vortex and estimate the effect of pressure distribution on the beam deflection. Sponsored by NSF Grant: CBET #1033117.

  20. Solved and unsolved problems in boiler systems. Learning from accidents

    International Nuclear Information System (INIS)

    Ozawa, Mamoru

    2000-01-01

    This paper begins with a brief review on the similarity law of conventional fossil-fuel-fired boilers. The concept is based on the fact that the heat release due to combustion in the furnace is restricted by the furnace volume but the heat absorption is restricted by the heat transfer surface area. This means that a small-capacity boiler has relatively high specific furnace heat release rate, about 10 MW/m 3 , and on the contrary a large-capacity boiler has lower value. The surface-heat-flux limit is mainly dominated by the CHF inside the water-wall tubes of the boiler furnace, about 350 kW/m 2 . This heat-flux limit is almost the same order independently on the capacity of boilers. For the safety of water-walls, it is essential to retain suitable water circulation, i.e. circulation ratio and velocity of water. This principle is a common knowledge of boiler designer, but actual situation is not the case. Newly designed boilers often suffer from similar accidents, especially burnout due to circulation problems. This paper demonstrates recent accidents encountered in practical boilers, and raises problems of rather classical but important two-phase flow and heat transfer. (author)

  1. Coherent beam-beam effect

    International Nuclear Information System (INIS)

    Chao, A.W.; Keil, E.

    1979-06-01

    The stability of the coherent beam-beam effect between rigid bunches is studied analytically and numerically for a linear force by evaluating eigenvalues. For a realistic force, the stability is investigated by following the bunches for many revolutions. 4 refs., 13 figs., 2 tabs

  2. Sino-Danish Brain Circulation

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Du, Xiangyun; Søndergaard, Morten Karnøe

    2014-01-01

    China is faced with urgent needs to develop an economically and environmentally sustainable economy based on innovation and knowledge. Brain circulation and research and business investments from the outside are central for this development. Sino-American brain circulation and research...... and investment by overseas researchers and entrepreneurs are well described. In that case, the US is the center of global R&D and S&T. However, the brain circulation and research and investments between a small open Scandinavian economy, such as Denmark, and the huge developing economy of China are not well...... understood. In this case, Denmark is very highly developed, but a satellite in the global R&D and S&T system. With time and the growth of China as a R&D and S&T power house, both Denmark and China will benefit from brain circulation between them. Such brain circulation is likely to play a key role in flows...

  3. Development Status of Accident Tolerant Fuel Cladding for LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Gil; Kim, Il-Hyun; Jung, Yang-Il; Park, Dong-Jun; Park, Jung-Hwan; Yang, Jae-Ho; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Hydrogen explosions and the release of radionuclides are caused by severe damage of current nuclear fuels, which are composed of fuel pellets and fuel cladding, during an accident. To reduce the damage to the public, the fuels have to enhance their integrity under an accident environment. Enhanced accident tolerance fuels (ATFs) can tolerate a loss of active cooling in the reactor core for a considerably longer time period during design-basis and beyond design-basis events while maintaining or improving the fuel performance during normal operations as well as operational transients, in comparison with the current UO{sub 2}-Zr alloy system used in the LWR. Surface modified Zr cladding as a new concept was suggested to apply an enhanced ATF cladding. The aim of the partial ODS treatment is to increase the high-temperature strength to suppress the ballooning/rupture behavior of fuel cladding during an accident event. The target of the surface coating is to increase the corrosion resistance during normal operation and increase the oxidation resistance during an accident event. The partial ODS treatment of Zircaloy-4 cladding can be produced using a laser beam scanning method with Y2O3 powder, and the surface Cr-alloy and Cr/FeCrAl coating on Zircaloy-4 cladding can be obtained after the development of 3D laser coating and arc ion plating technologies.

  4. Simulation of thermal response of the 250 MWT modular HTGR during hypothetical uncontrolled heatup accidents

    International Nuclear Information System (INIS)

    Harrington, R.M.; Ball, S.J.

    1985-01-01

    One of the central design features of the 250 MWT modular HTGR is the ability to withstand uncontrolled heatup accidents without severe consequences. This paper describes calculational studies, conducted to test this design feature. A multi-node thermal-hydraulic model of the 250 MWT modular HTGR reactor core was developed and implemented in the IBM CSMP (Continuous System Modeling Program) simulation language. Survey calculations show that the loss of forced circulation accident with loss of steam generator cooling water and with accidental depressurization is the most severe heatup accident. The peak hot-spot fuel temperature is in the neighborhood of 1600 0 C. Fuel failure and fission product releases for such accidents would be minor. Sensitivity studies show that code input assumptions for thermal properties such as the side reflector conductivity have a significant effect on the peak temperature. A computer model of the reactor vessel cavity concrete wall and its surrounding earth was developed to simulate the extremely unlikely and very slowly-developing heatup accident that would take place if the worst-case loss of forced primary coolant circulation accident were further compounded by the loss of cooling water to the reactor vessel cavity liner cooling system. Results show that the ability of the earth surrounding the cavity to act as a satisfactory long-term heat sink is very sensitive to the assumed rate of decay heat generation and on the effective thermal conductivity of the earth

  5. Natural Circulation with Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Mathisen, R P

    1967-09-15

    A number of parameters with dominant influence on the power level at hydrodynamic instability in natural circulation, two-phase flow, have been studied experimentally. The geometrical dependent quantities were: the system driving head, the boiling channel and riser dimensions, the single-phase as well as the two phase flow restrictions. The parameters influencing the liquid properties were the system pressure and the test section inlet subcooling. The threshold of instability was determined by plotting the noise characteristics in the mass flow records against power. The flow responses to artificially obtained power disturbances at instability conditions were also measured in order to study the nature of hydrodynamic instability. The results presented give a review over relatively wide ranges of the main parameters, mainly concerning the coolant performance in both single and parallel boiling channel flow. With regard to the power limits the experimental results verified that the single boiling channel performance was intimately related to that of the parallel channels. In the latter case the additional inter-channel factors with attenuating effects were studied. Some optimum values of the parameters were observed.

  6. Containment severe accident thermohydraulic phenomena

    International Nuclear Information System (INIS)

    Frid, W.

    1991-08-01

    This report describes and discusses the containment accident progression and the important severe accident containment thermohydraulic phenomena. The overall objective of the report is to provide a rather detailed presentation of the present status of phenomenological knowledge, including an account of relevant experimental investigations and to discuss, to some extent, the modelling approach used in the MAAP 3.0 computer code. The MAAP code has been used in Sweden as the main tool in the analysis of severe accidents. The dependence of the containment accident progression and containment phenomena on the initial conditions, which in turn are heavily dependent on the in-vessel accident progression and phenomena as well as associated uncertainties, is emphasized. The report is in three parts dealing with: * Swedish reactor containments, the severe accident mitigation programme in Sweden and containment accident progression in Swedish PWRs and BWRs as predicted by the MAAP 3.0 code. * Key non-energetic ex-vessel phenomena (melt fragmentation in water, melt quenching and coolability, core-concrete interaction and high temperature in containment). * Early containment threats due to energetic events (hydrogen combustion, high pressure melt ejection and direct containment heating, and ex-vessel steam explosions). The report concludes that our understanding of the containment severe accident progression and phenomena has improved very significantly over the parts ten years and, thereby, our ability to assess containment threats, to quantify uncertainties, and to interpret the results of experiments and computer code calculations have also increased. (au)

  7. Expert software for accident identification

    International Nuclear Information System (INIS)

    Dobnikar, M.; Nemec, T.; Muehleisen, A.

    2003-01-01

    Each type of an accident in a Nuclear Power Plant (NPP) causes immediately after the start of the accident variations of physical parameters that are typical for that type of the accident thus enabling its identification. Examples of these parameter are: decrease of reactor coolant system pressure, increase of radiation level in the containment, increase of pressure in the containment. An expert software enabling a fast preliminary identification of the type of the accident in Krsko NPP has been developed. As input data selected typical parameters from Emergency Response Data System (ERDS) of the Krsko NPP are used. Based on these parameters the expert software identifies the type of the accident and also provides the user with appropriate references (past analyses and other documentation of such an accident). The expert software is to be used as a support tool by an expert team that forms in case of an emergency at Slovenian Nuclear Safety Administration (SNSA) with the task to determine the cause of the accident, its most probable scenario and the source term. The expert software should provide initial identification of the event, while the final one is still to be made after appropriate assessment of the event by the expert group considering possibility of non-typical events, multiple causes, initial conditions, influences of operators' actions etc. The expert software can be also used as an educational/training tool and even as a simple database of available accident analyses. (author)

  8. Fukushima accident - reasons and impacts

    International Nuclear Information System (INIS)

    Slugen, V.

    2011-01-01

    The Fukushima accident influenced dramatically the current view on safety of nuclear facilities. Consideration about possible impacts of natural catastrophe in design of nuclear facilities seems to be much more important than before. European commission is focused on the stress-tests at nuclear power plants. His paper will go more in details having in mind reasons and impacts of Fukushima accident (Author)

  9. First Responders and Criticality Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Valerie L. Putman; Douglas M. Minnema

    2005-11-01

    Nuclear criticality accident descriptions typically include, but do not focus on, information useful to first responders. We studied these accidents, noting characteristics to help (1) first responders prepare for such an event and (2) emergency drill planners develop appropriate simulations for training. We also provide recommendations to help people prepare for such events in the future.

  10. Occupational accidents among mototaxi drivers.

    Science.gov (United States)

    Amorim, Camila Rego; de Araújo, Edna Maria; de Araújo, Tânia Maria; de Oliveira, Nelson Fernandes

    2012-03-01

    The use of motorcycles as a means of work has contributed to the increase in traffic accidents, in particular, mototaxi accidents. The aim of this study was to estimate and characterize the incidence of occupational accidents among the mototaxis registered in Feira de Santana, BA. This is a cross-sectional study with descriptive and census data. Of the 300 professionals registered at the Municipal Transportation Service, 267 professionals were interviewed through a structured questionnaire. Then, a descriptive analysis was conducted and the incidence of accidents was estimated based on the variables studied. Relative risks were calculated and statistical significance was determined using the chi-square test and Fisher's exact test, considering p accidents were observed in 10.5% of mototaxis. There were mainly minor injuries (48.7%), 27% of them requiring leaves of absence from work. There was an association between the days of work per week, fatigue in lower limbs and musculoskeletal complaints, and accidents. Knowledge of the working conditions and accidents involved in this activity can be of great importance for the adoption of traffic education policies, and to help prevent accidents by improving the working conditions and lives of these professionals.

  11. Beam diagnostic developments at the cooler synchrotron COSY-J ...

    Indian Academy of Sciences (India)

    To measure the beam quality in case of fast and slow ... Four internal target areas [1,2] are available for experiments with the circulating beam. ..... tors work at normal air condition which is a great advantage concerning costs and service.

  12. LHC beam dumping system Extraction channel layout and acceptance

    CERN Document Server

    Goddard, B; Uythoven, J; Veness, R; Weterings, W

    2003-01-01

    The LHC beam dumping system must safely abort the LHC beams under all conditions, including those resulting from abnormal behaviour of machine elements or subsystems of the beam dumping system itself. The extraction channels must provide sufficient aperture both for the circulating and extracted beams, over the whole energy range and under various beam parameters. These requirements impose tight constraints on the tolerances of various extraction channel components, and also on the allowed range of beam positions in the region of these components. Operation of the beam dumping system under various fault states has been considered, and the resulting apertures calculated. After describing briefly the beam dumping system and the extraction channel geometry, the various assumptions made in the analysis are presented, before deriving tolerance limits for the relevant equipment and beam parameters.

  13. Barriers to learning from incidents and accidents

    NARCIS (Netherlands)

    Dechy, N.; Dien, Y.; Drupsteen, L.; Felicio, A.; Cunha, C.; Roed-Larsen, S.; Marsden, E.; Tulonen, T.; Stoop, J.; Strucic, M.; Vetere Arellano, A.L.; Vorm, J.K.J. van der; Benner, L.

    2015-01-01

    This document provides an overview of knowledge concerning barriers to learning from incidents and accidents. It focuses on learning from accident investigations, public inquiries and operational experience feedback, in industrial sectors that are exposed to major accident hazards. The document

  14. Probability of spent fuel transportation accidents

    International Nuclear Information System (INIS)

    McClure, J.D.

    1981-07-01

    The transported volume of spent fuel, incident/accident experience and accident environment probabilities were reviewed in order to provide an estimate of spent fuel accident probabilities. In particular, the accident review assessed the accident experience for large casks of the type that could transport spent (irradiated) nuclear fuel. This review determined that since 1971, the beginning of official US Department of Transportation record keeping for accidents/incidents, there has been one spent fuel transportation accident. This information, coupled with estimated annual shipping volumes for spent fuel, indicated an estimated annual probability of a spent fuel transport accident of 5 x 10 -7 spent fuel accidents per mile. This is consistent with ordinary truck accident rates. A comparison of accident environments and regulatory test environments suggests that the probability of truck accidents exceeding regulatory test for impact is approximately 10 -9 /mile

  15. 29 CFR 1960.29 - Accident investigation.

    Science.gov (United States)

    2010-07-01

    ... reflective of the seriousness of the accident. (b) In any case, each accident which results in a fatality or... evidence uncovered during accident investigations which would be of benefit in developing a new OSHA...

  16. 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...

  17. Accident sequence quantification with KIRAP

    International Nuclear Information System (INIS)

    Kim, Tae Un; Han, Sang Hoon; Kim, Kil You; Yang, Jun Eon; Jeong, Won Dae; Chang, Seung Cheol; Sung, Tae Yong; Kang, Dae Il; Park, Jin Hee; Lee, Yoon Hwan; Hwang, Mi Jeong.

    1997-01-01

    The tasks of probabilistic safety assessment(PSA) consists of the identification of initiating events, the construction of event tree for each initiating event, construction of fault trees for event tree logics, the analysis of reliability data and finally the accident sequence quantification. In the PSA, the accident sequence quantification is to calculate the core damage frequency, importance analysis and uncertainty analysis. Accident sequence quantification requires to understand the whole model of the PSA because it has to combine all event tree and fault tree models, and requires the excellent computer code because it takes long computation time. Advanced Research Group of Korea Atomic Energy Research Institute(KAERI) has developed PSA workstation KIRAP(Korea Integrated Reliability Analysis Code Package) for the PSA work. This report describes the procedures to perform accident sequence quantification, the method to use KIRAP's cut set generator, and method to perform the accident sequence quantification with KIRAP. (author). 6 refs

  18. Accident sequence quantification with KIRAP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Un; Han, Sang Hoon; Kim, Kil You; Yang, Jun Eon; Jeong, Won Dae; Chang, Seung Cheol; Sung, Tae Yong; Kang, Dae Il; Park, Jin Hee; Lee, Yoon Hwan; Hwang, Mi Jeong

    1997-01-01

    The tasks of probabilistic safety assessment(PSA) consists of the identification of initiating events, the construction of event tree for each initiating event, construction of fault trees for event tree logics, the analysis of reliability data and finally the accident sequence quantification. In the PSA, the accident sequence quantification is to calculate the core damage frequency, importance analysis and uncertainty analysis. Accident sequence quantification requires to understand the whole model of the PSA because it has to combine all event tree and fault tree models, and requires the excellent computer code because it takes long computation time. Advanced Research Group of Korea Atomic Energy Research Institute(KAERI) has developed PSA workstation KIRAP(Korea Integrated Reliability Analysis Code Package) for the PSA work. This report describes the procedures to perform accident sequence quantification, the method to use KIRAP`s cut set generator, and method to perform the accident sequence quantification with KIRAP. (author). 6 refs.

  19. 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...

  20. Dose assessment in radiological accidents

    International Nuclear Information System (INIS)

    Donkor, S.

    2013-04-01

    The applications of ionizing radiation bring many benefits to humankind, ranging from power generation to uses in medicine, industry and agriculture. Facilities that use radiation source require special care in the design and operation of equipment to prevent radiation injury to workers or to the public. Despite considerable development of radiation safety, radiation accidents do happen. The purpose of this study is therefore to discuss how to assess doses to people who will be exposed to a range of internal and external radiation sources in the event of radiological accidents. This will go a long way to complement their medical assessment thereby helping to plan their treatment. Three radiological accidents were reviewed to learn about the causes of those accidents and the recommendations that were put in place to prevent recurrence of such accidents. Various types of dose assessment methods were discussed.(au)

  1. Severe accidents in nuclear reactors

    International Nuclear Information System (INIS)

    Ohai, Dumitru; Dumitrescu, Iulia; Tunaru, Mariana

    2004-01-01

    The likelihood of accidents leading to core meltdown in nuclear reactors is low. The consequences of such an event are but so severe that developing and implementing of adequate measures for preventing or diminishing the consequences of such events are of paramount importance. The analysis of major accidents requires sophisticated computation codes but necessary are also relevant experiments for checking the accuracy of the predictions and capability of these codes. In this paper an overview of the severe accidents worldwide with definitions, computation codes and relating experiments is presented. The experimental research activity of severe accidents was conducted in INR Pitesti since 2003, when the Institute jointed the SARNET Excellence Network. The INR activity within SARNET consists in studying scenarios of severe accidents by means of ASTEC and RELAP/SCDAP codes and conducting bench-scale experiments

  2. JCO criticality accident termination operation

    International Nuclear Information System (INIS)

    Kanamori, Masashi

    2001-12-01

    On September 30 at around 10:35 AM, criticality accident occurred at the JCO's conversion building in Tokai-mura. Since criticality accident had not been anticipated, neither devices for termination of criticality accident nor neutron detectors were available. Immediately after the information of the accident, our emergency staff (Japan Nuclear Cycle development institute staff) went to JCO site, to measure the intensity of neutrons and gammas. There were four main tasks, first one was to measure the radiation intensity, second one was to terminate the criticality accident, third one is to alert the residents surrounding the JCO site, fourth one is to evacuate the employees in the site. These tasks were successfully performed until October 1. This paper describes about how these operations were performed by the relevant staffs. (author)

  3. Homocysteine and cerebrovascular accidents.

    Science.gov (United States)

    Datta, Saikat; Pal, Salil K; Mazumdar, Hirak; Bhandari, Biswanath; Bhattacherjee, Sharmistha; Pandit, Sudipta

    2009-06-01

    Hyperhomocysteinaemia is rapidly emerging as an important risk factor for coronary artery disease, possibly because of its propensity to accelerate atherosclerosis. Whether it is also a risk factor for cerebrovascular accidents (CVA) is a matter of debate till now, as there are conflicting results of the various prospective studies. The present study was performed to correlate the levels of plasma homocysteine levels with that of ischaemic and haemorrhagic CVA. Forty-two cases of CVA were randomly selected over a period of one year, and their risk factors were assessed. It was observed that serum homocysteine levels were significantly raised in those with intracerebral infarcts when compared to those with intracerebral haemorrhage, although homocysteine levels didn't prove to be prognostically significant.

  4. Severe accident management. Prevention and Mitigation

    International Nuclear Information System (INIS)

    1992-01-01

    Effective planning for the management of severe accidents at nuclear power plants can produce both a reduction in the frequency of such accidents as well as the ability to mitigate their consequences if and when they should occur. This report provides an overview of accident management activities in OECD countries. It also presents the conclusions of a group of international experts regarding the development of accident management methods, the integration of accident management planning into reactor operations, and the benefits of accident management

  5. The Fukushima accident

    International Nuclear Information System (INIS)

    Loria Meneses, Luis Guillermo

    2011-01-01

    The accident happened on March 11, 2011 in the nuclear reactors at the Fukushima plant, Japan, is described. The reactors of the Fukushima plant have been power reactors. The electrical energy is produced by use of the heat released in the fission. Nuclear reactors were affected after of the power outage as a result of the earthquake and the tsunami, and this has kept in operation the refrigeration systems. The japanese reactors have been fission reactors and have used uranium 235 or plutonium 239 as fissionable material. The nuclear reactions of fission are explained. The control of the nuclear reactions at Fukushima was complicated by the decreased of the neutrons absorption and has produced more reactions, generating great amounts of heat. The steam contaminated with the products of fission is produced by to cool the reactor with water. The fissionable material released is dragged until the atmosphere. Radioactive contamination at sites near the reactor was covered in a zone of exclusion with a radius of 30 km. The effects of radioactive contamination in the zone of exclusion are mentioned. The radioactive material from Japan has traveled with the wind in direction toward the north pole. The radioactive cloud has continued until to reach the north Africa and south of Europe. The cloud has approximated to Costa Rica, but the activity of the material found has been less of 0,01 Bq/m3. The Centro de Investigacion en Ciencias Atomicas, Nucleares y Moleculares (Cicanum) has initiated the collection of soil samples, water and earth products to detect part of the radioactive material from the cloud. The Cicanum has had modern equipments to quantify the specific concentrations of radioactive isotope, alpha emitters, beta and gamma, in food, water and milk. The Cicanum has maintained the radiological surveillance of foods after the Chernobyl accident [es

  6. Electron clearing for the ISA proton beam

    International Nuclear Information System (INIS)

    Herrera, J.C.

    1976-01-01

    The circulating protons in the ISABELLE intersecting storage ring accelerator will collide with the residual gas in the vacuum chamber. The electrons produced will tend to be captured by the potential well of the beam itself and result in a neutralization of the space charge of the beam. A detailed analysis is given of the various mechanisms which can be used to reduce the net degree of beam neutralization. It is concluded that the average neutralization will be about 10 -4 for a residual gas pressure of 3 x 10 -11 torr of hydrogen

  7. Aspects of water and air ingress accidents in HTRs

    International Nuclear Information System (INIS)

    Wolters, J.

    1981-01-01

    The work has contributed towards improving the understanding of the processes taking place during water and air ingress accidents. The favourable design features of the THTR limit the pressure build-up in the primary circuit to values below critical values in water ingress accidents even when the source of water is not identified and shut-off. A pressure reduction by safety valves is in this case not necessary so that the accident consequences remain confined in the primary circuit. The expected air ingress rates following a depressurization accident through an opening in the top head of the PCRV are extremely small in the case of complete integration of the primary circuit in the PCRV. The chemical processes in the primary circuit remain so limited that no danger for the fuel elements and the containment exists. The often feared ''graphite fire'' can be excluded even in the case when the circulators of the after-heat removal systems take in a high percentage of containment atmosphere. The core is cooled down safely

  8. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    Considerable experience has now been gained with the various beam transport lines, and a number of minor changes have been made to improve the ease of operation. These include: replacement of certain little-used slits by profile monitors (harps or scanners); relocation of steering magnets, closer to diagnostic harps or profile scanners; installation of a scanner inside the isocentric neutron therapy system; and conversion of a 2-doublet quadrupole telescope (on the neutron therapy beamline) to a 2-triplet telescope. The beam-swinger project has been delayed by very late delivery of the magnet iron to the manufacturer, but is now progressing smoothly. The K=600 spectrometer magnets have now been delivered and are being assembled for field mapping. The x,y-table with its associated mapping equipment is complete, together with the driver software. One of the experimental areas has been dedicated to the production of collimated neutron beams and has been equipped with a bending magnet and beam dump, together with steel collimators fixed at 4 degrees intervals from 0 degrees to 16 degrees. Changes to the target cooling and shielding system for isotope production have led to a request for much smaller beam spot sizes on target, and preparations have been made for rearrangement of the isotope beamline to permit installation of quadrupole triplets on the three beamlines after the switching magnet. A practical system of quadrupoles for matching beam properties to the spectrometer has been designed. 6 figs

  9. The ATLAS beam conditions monitor

    CERN Document Server

    Mikuz, M; Dolenc, I; Kagan, H; Kramberger, G; Frais-Kölbl, H; Gorisek, A; Griesmayer, E; Mandic, I; Pernegger, H; Trischuk, W; Weilhammer, P; Zavrtanik, M

    2006-01-01

    The ATLAS beam conditions monitor is being developed as a stand-alone device allowing to separate LHC collisions from background events induced either on beam gas or by beam accidents, for example scraping at the collimators upstream the spectrometer. This separation can be achieved by timing coincidences between two stations placed symmetric around the interaction point. The 25 ns repetition of collisions poses very stringent requirements on the timing resolution. The optimum separation between collision and background events is just 12.5 ns implying a distance of 3.8 m between the two stations. 3 ns wide pulses are required with 1 ns rise time and baseline restoration in 10 ns. Combined with the radiation field of 10/sup 15/ cm/sup -2/ in 10 years of LHC operation only diamond detectors are considered suitable for this task. pCVD diamond pad detectors of 1 cm/sup 2/ and around 500 mum thickness were assembled with a two-stage RF current amplifier and tested in proton beam at MGH, Boston and SPS pion beam at...

  10. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    Science.gov (United States)

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Larry J.; Bower, Amy S.; Köhl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24°N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model's winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow.

  11. Ultrasound Instrumentation for Beam Diagnostics and Accelerating Structures Control

    CERN Document Server

    Moiseev, V I

    2005-01-01

    Sensitive elements and electronics for ultrasound measurements at conducting walls of beam pipes and accelerating structures are described. Noise protected instrumentation provides ultrasound spectra analysis in a wide frequency range up to 5 MHz.In circular accelerators, ultrasound fields in conducting walls of beam pipe represent the space-time characteristics of circulating beams. In accelerating structures, real high power operation modes of structure can be studied by outer ultrasound monitors. The experimental results at KSRS accelerators are discussed.

  12. Construction industry accidents in Spain.

    Science.gov (United States)

    Camino López, Miguel A; Ritzel, Dale O; Fontaneda, Ignacio; González Alcantara, Oscar J

    2008-01-01

    This paper analyzed industrial accidents that take place on construction sites and their severity. Eighteen variables were studied. We analyzed the influence of each of these with respect to the severity and fatality of the accident. This descriptive analysis was grounded in 1,630,452 accidents, representing the total number of accidents suffered by workers in the construction sector in Spain over the period 1990-2000. It was shown that age, type of contract, time of accident, length of service in the company, company size, day of the week, and the remainder of the variables under analysis influenced the seriousness of the accident. IMPACT ON INJURY PREVENTION: The results obtained show that different training was needed, depending on the severity of accidents, for different age, length of service in the company, organization of work, and time when workers work. The research provides an insight to the likely causes of construction injuries in Spain. As a result of the analysis, industries and governmental agencies in Spain can start to provide appropriate strategies and training to the construction workers.

  13. Contributing factors in construction accidents.

    Science.gov (United States)

    Haslam, R A; Hide, S A; Gibb, A G F; Gyi, D E; Pavitt, T; Atkinson, S; Duff, A R

    2005-07-01

    This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

  14. Primary disability of the Chernobyl Accident consequences liquidators

    International Nuclear Information System (INIS)

    Zubritskij, M.K.; Plakhotya, L.P.; Kalinina, T.V.; Zhilinskaya, E.I.

    1994-01-01

    The structure of courses of the primary invalidism of the Chernobyl accident consequences liquidators is studies. The main reasons of the loss of a capacity for work are blood circulation diseases (41.9%), neoplasms (19.9%), diseases of the nervous system and sense organs (9.7%), mental disorders (5.9%) and endocrine diseases (5.5%). The invalids distribution in the different regions and in different age groups according to the disease forms is analysed. The average durations of the diseases resulting in the primary invalidism are about 2.8 years. In average the illnesses began in the 3.1 years. 6 refs

  15. Impact of the Fukushima Accident on Current Fast Reactor Monju

    International Nuclear Information System (INIS)

    Ohira, Hiroaki

    2012-01-01

    Conclusions: • Based on the lessons learned from the Fukushima Dai-ichi NPS accidents, the emergency safety countermeasures and the enhanced countermeasures for the reactor, EVST and SFP have been conducted in Monju as of March 2012. • Plant dynamics analysis using possible conditions were also performed to confirm the cooling capabilities when a tsunami-induced SBO continued over a long period. • These results indicated that the decay heat produced from the core and the EVST could be removed safely by the natural circulation in the cooling systems, and that from the SFP could also removed only if water would be supplied in a few months interval

  16. International aspects of nuclear accidents

    International Nuclear Information System (INIS)

    Uematsu, K.

    1989-09-01

    The accident at Chernobyl revealed that there were shortcomings and gaps in the existing international mechanisms and brought home to governments the need for stronger measures to provide better protection against the risks of severe accidents. The main thrust of international co-operation with regard to nuclear safety issues is aimed at achieving a uniformly high level of safety in nuclear power plants through continuous exchanges of research findings and feedback from reactor operating experience. The second type of problem posed in the event of an accident resulting in radioactive contamination of several countries relates to the obligation to notify details of the circumstances and nature of the accident speedily so that the countries affected can take appropriate protective measures and, if necessary, organize mutual assistance. Giving the public accurate information is also an important aspect of managing an emergency situation arising from a severe accident. Finally, the confusion resulting from the unwarranted variety of protective measures implemented after the Chernobyl accident has highlighted the need for international harmonization of the principles and scientific criteria applicable to the protection of the public in the event of an accident and for a more consistent approach to emergency plans. The international conventions on third party liability in the nuclear energy sector (Paris/Brussels Conventions and the Vienna Convention) provide for compensation for damage caused by nuclear accidents in accordance with the rules and jurisdiction that they lay down. These provisions impose obligations on the operator responsible for an accident, and the State where the nuclear facility is located, towards the victims of damage caused in another country

  17. Accident Analysis and Highway Safety

    Directory of Open Access Journals (Sweden)

    Omar Noorliyana

    2017-01-01

    Full Text Available Since 2010, Federal Route FT050 (Jalan Batu Pahat-Kluang has undergone many changes, including the improvement of geometric features (i.e., construction of median, dedicated U-turns and additional lanes and upgrading the quality of the road surface. Unfortunately, even with these enhancements, accidents continue to occur along this route. This study covered both accident analysis and blackspot study. Accident point weightage was used to identify blackspot locations. The results reveal hazardous road locations and blackspot ranking along the route.

  18. Medical care of radiation accidents

    International Nuclear Information System (INIS)

    Nakao, Isamu

    1986-02-01

    This monograph, divided into six chapters, focuses on basic knowledge and medical strategies for radiation accidents. Chapters I to V deal with practice in emergency care for radiation exposure, covering 1) medical strategies for radiation accidents, 2) personnel dosimetry and monitoring, 3) nuclear facilities and their surrounding areas with the potential for creating radiation accidents, and emergency medical care for exposed persons, 4) emergency care procedures for radiation exposure and radioactive contamination, and 5) radiation hazards and their treatment. The last chapter provides some references. (Namekawa, K.)

  19. Judicial autopsy of radiation accidents

    International Nuclear Information System (INIS)

    Kannan, P.M.

    1990-01-01

    This paper discusses issues regarding the judicial autopsy of radiation accidents. In the litigation which follows a radiation accident, a claimant calls on the legal system to adjudicate a dispute. Scientific questions are thrust upon the court. The legal system (through attorneys for the parties) then invites scientists to assist the court in resolving such questions. The invitation, however, does not allow the scientist to bring along his full kit. Experimentation, such as repeating the accident with dosimeters to gather more accurate data, is generally not allowed. Also, the scientist must give up his practice of choosing which questions he will pursue

  20. A review of criticality accidents

    International Nuclear Information System (INIS)

    Stratton, W.R.; Smith, D.R.

    1989-03-01

    Criticality accidents and the characteristics of prompt power excursions are discussed. Forty-one accidental power transients are reviewed. In each case where available, enough detail is given to help visualize the physical situation, the cause or causes of the accident, the history and characteristics of the transient, the energy release, and the consequences, if any, to personnel and property. Excursions associated with large power reactors are not included in this study, except that some information on the major accident at the Chernobyl reactor in April 1986 is provided in the Appendix. 67 refs., 21 figs., 2 tabs

  1. The handling of radiation accidents

    International Nuclear Information System (INIS)

    1977-01-01

    The symposium was attended by 204 participants from 39 countries and 5 international organizations. Forty-two papers were presented in 8 sessions. The purpose of the meeting was to foster an exchange of experiences gained in establishing and exercising plans for mitigating the effects of radiation accidents and in the handling of actual accident situations. Only a small number of accidents were reported at the symposium, and this reflects the very high standards of safety that has been achieved by the nuclear industry. No accidents of radiological significance were reported to have occurred at commercial nuclear power plants. Of the accidents reported, industrial radiography continues to be the area in which most of the radiation accidents occur. The experience gained in the reported accident situations served to confirm the crucial importance of the prompt availability of medical and radiological services, particularly in the case of uptake of radioactive material, and emphasized the importance of detailed investigation into the causes of the accident in order to improve preventative measures. One of the principal themes of the symposium involved emergency procedures related to nuclear power plant accidents, and several papers defining the scope, progression and consequences of design base accidents for both thermal and fast reactor systems were presented. These were complemented by papers defining the resultant protection requirements that should be satisfied in the establishment of plans designed to mitigate the effects of the postulated accident situations. Several papers were presented describing existing emergency organizational arrangements relating both to specific nuclear power plants and to comprehensive national schemes, and a particularly informative session was devoted to the topic of training of personnel in the practical conduct of emergency arrangements. The general feeling of the participants was one of studied confidence in the competence and

  2. Steam generator and circulator model for the HELAP code

    International Nuclear Information System (INIS)

    Ludewig, H.

    1975-07-01

    An outline is presented of the work carried out in the 1974 fiscal year on the GCFBR safety research project consisting of the development of improved steam generator and circulator (steam turbine driven helium compressor) models which will eventually be inserted in the HELAP (1) code. Furthermore, a code was developed which will be used to generate steady state input for the primary and secondary sides of the steam generator. The following conclusions and suggestions for further work are made: (1) The steam-generator and circulator model are consistent with the volume and junction layout used in HELAP, (2) with minor changes these models, when incorporated in HELAP, could be used to simulate a direct cycle plant, (3) an explicit control valve model is still to be developed and would be very desirable to control the flow to the turbine during a transient (initially this flow will be controlled by using the existing check valve model); (4) the friction factor in the laminar flow region is computed inaccurately, this might cause significant errors in loss-of-flow accidents; and (5) it is felt that HELAP will still use a large amount of computer time and will thus be limited to design basis accidents without scram or loss of flow transients with and without scram. Finally it may also be used as a test bed for the development of prototype component models which would be incorporated in a more sophisticated system code, developed specifically for GCFBR's

  3. Quantum beams

    International Nuclear Information System (INIS)

    Uesaka, Mitsuru

    2003-01-01

    Present state and future prospect are described on quantum beams for medical use. Efforts for compactness of linac for advanced cancer therapy have brought about the production of machines like Accuray's CyberKnife and TOMOTHERAPY (Tomo Therapy Inc.) where the acceleration frequency of X-band (9-11 GHz) is used. For cervical vein angiography by the X-band linac, a compact hard X-ray source is developed which is based on the (reverse) Compton scattering through laser-electron collision. More intense beam and laser are necessary at present. A compact machine generating the particle beam of 10 MeV-1 GeV (laser-plasma accelerator) for cancer therapy is also developed using the recent compression technique (chirped-pulse amplification) to generate laser of >10 TW. Tokyo University is studying for the electron beam with energy of GeV order, for the laser-based synchrotron X-ray, and for imaging by the short pulse ion beam. Development of advanced compact accelerators is globally attempted. In Japan, a virtual laboratory by National Institute of Radiological Sciences (NIRS), a working group of universities and research facilities through the Ministry of Education, Culture, Sports, Science and Technology, started in 2001 for practical manufacturing of the above-mentioned machines for cancer therapy and for angiography. Virtual Factory (Inc.), a business venture, is to be stood in future. (N.I.)

  4. Beam Dynamics in an Electron Lens with the Warp Particle-in-cell Code

    CERN Document Server

    Stancari, Giulio; Redaelli, Stefano

    2014-01-01

    Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The design of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.

  5. Underreporting of maritime accidents to vessel accident databases.

    Science.gov (United States)

    Hassel, Martin; Asbjørnslett, Bjørn Egil; Hole, Lars Petter

    2011-11-01

    Underreporting of maritime accidents is a problem not only for authorities trying to improve maritime safety through legislation, but also to risk management companies and other entities using maritime casualty statistics in risk and accident analysis. This study collected and compared casualty data from 01.01.2005 to 31.12.2009, from IHS Fairplay and the maritime authorities from a set of nations. The data was compared to find common records, and estimation of the true number of occurred accidents was performed using conditional probability given positive dependency between data sources, several variations of the capture-recapture method, calculation of best case scenario assuming perfect reporting, and scaling up a subset of casualty information from a marine insurance statistics database. The estimated upper limit reporting performance for the selected flag states ranged from 14% to 74%, while the corresponding estimated coverage of IHS Fairplay ranges from 4% to 62%. On average the study results document that the number of unreported accidents makes up roughly 50% of all occurred accidents. Even in a best case scenario, only a few flag states come close to perfect reporting (94%). The considerable scope of underreporting uncovered in the study, indicates that users of statistical vessel accident data should assume a certain degree of underreporting, and adjust their analyses accordingly. Whether to use correction factors, a safety margin, or rely on expert judgment, should be decided on a case by case basis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Nonlinear interaction of colliding beams in particle storage rings

    International Nuclear Information System (INIS)

    Herrera, J.C.; Month, M.

    1979-01-01

    When two beams of high energy particles moving in opposite directions are brought into collision, a large amount of energy is available for the production of new particles. However to obtain a sufficiently high event rate for rare processes, such as the production of the intermediate vector boson (Z 0 and W +- ), large beam currents are also required. Under this circumstance, the high charge density of one beam results in a classical electromagnetic interaction on the particles in the other beam. This very nonlinear space charge force, caled the beam-beam force, limits the total circulating charge and, thereby, the ultimate performance of the colliding ring system. The basic nature of the beam-beam force is discussed, indicating how it is quite different in the case of continuous beams, which cross each other at an angle as compared to the case of bunched beams which collide head-on. Some experimental observations on the beam-beam interaction in proton-proton and electron-positron beams are then reviewed and interpreted. An important aspect of the beam-beam problem in storage rings is to determine at what point in the analysis of the particle dynamics is it relevant to bring in the concepts of stochasticity, slow diffusion, and resonance overlap. These ideas are briefly discussed

  7. Importance of beam-beam tune spread to collective beam-beam instability in hadron colliders

    International Nuclear Information System (INIS)

    Jin Lihui; Shi Jicong

    2004-01-01

    In hadron colliders, electron-beam compensation of beam-beam tune spread has been explored for a reduction of beam-beam effects. In this paper, effects of the tune-spread compensation on beam-beam instabilities were studied with a self-consistent beam-beam simulation in model lattices of Tevatron and Large Hodron Collider. It was found that the reduction of the tune spread with the electron-beam compensation could induce a coherent beam-beam instability. The merit of the compensation with different degrees of tune-spread reduction was evaluated based on beam-size growth. When two beams have a same betatron tune, the compensation could do more harm than good to the beams when only beam-beam effects are considered. If a tune split between two beams is large enough, the compensation with a small reduction of the tune spread could benefit beams as Landau damping suppresses the coherent beam-beam instability. The result indicates that nonlinear (nonintegrable) beam-beam effects could dominate beam dynamics and a reduction of beam-beam tune spread by introducing additional beam-beam interactions and reducing Landau damping may not improve the stability of beams

  8. Beam dynamics

    International Nuclear Information System (INIS)

    Abell, D; Adelmann, A; Amundson, J; Dragt, A; Mottershead, C; Neri, F; Pogorelov, I; Qiang, J; Ryne, R; Shalf, J; Siegerist, C; Spentzouris, P; Stern, E; Venturini, M; Walstrom, P

    2006-01-01

    We describe some of the accomplishments of the Beam Dynamics portion of the SciDAC Accelerator Science and Technology project. During the course of the project, our beam dynamics software has evolved from the era of different codes for each physical effect to the era of hybrid codes combining start-of-the-art implementations for multiple physical effects to the beginning of the era of true multi-physics frameworks. We describe some of the infrastructure that has been developed over the course of the project and advanced features of the most recent developments, the interplay betwen beam studies and simulations and applications to current machines at Fermilab. Finally we discuss current and future plans for simulations of the International Linear Collider

  9. Accident response in France

    International Nuclear Information System (INIS)

    Duco, J.; L'Homme, A.; Queniart, D.

    1988-07-01

    French PWR power plant design relies basically on a deterministic approach. A probabilistic approach was introduced in France in the early seventies to define safety provisions against external impacts. In 1977 an overall safety objective was issued by the safety authority in terms of an upper probability limit for having unacceptable consequences. Additional measures were taken (the ''H'' operating procedures) to complement the automatic systems normally provided by the initial design, so as to safisfy the safety objective. The TMI-2 accident enhanced the interest in confused situations in which possible multiple equipment failure and/or unappropriate previous actions of the operators impede the implementation of any of the existing event-oriented procedures. In such situations, the objective becomes to avoid core-melt by any means available: this is the goal of the Ul symptom-oriented procedure. Whenever a core-melt occurs, the radioactive releases into the environment must be compatible with the feasibility of the off-site emergency plans; that means that for some hypothetical, but still conceivable scenarios, provisions have to be made to delay and limit the consequences of the loss of the containment: the U2, U4 and U5 ultimate procedures have been elaborated for that purpose. For the case of an emergency, a nationwide organization has been set up to provide the plant operator with a redundant technical expertise, to help him save his plant or mitigate the radiological consequences of a core-melt

  10. RENEB accident simulation exercise.

    Science.gov (United States)

    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; Della Monaca, Sara; Depuydt, Julie; De Sanctis, Stefania; Dobos, Katalin; Domene, Mercedes Moreno; Domínguez, Inmaculada; Facco, Eva; Fattibene, Paola; Frenzel, Monika; Monteiro Gil, Octávia; Gonon, Géraldine; Gregoire, Eric; Gruel, Gaëtan; Hadjidekova, Valeria; Hatzi, Vasiliki I; Hristova, Rositsa; Jaworska, Alicja; Kis, Enikő; Kowalska, Maria; Kulka, Ulrike; Lista, Florigio; Lumniczky, Katalin; Martínez-López, Wilner; Meschini, Roberta; Moertl, Simone; Moquet, Jayne; Noditi, Mihaela; Oestreicher, Ursula; Orta Vázquez, Manuel Luis; Palma, Valentina; Pantelias, Gabriel; Montoro Pastor, Alegria; Patrono, Clarice; Piqueret-Stephan, Laure; Quattrini, Maria Cristina; Regalbuto, Elisa; Ricoul, Michelle; Roch-Lefevre, Sandrine; Roy, Laurence; Sabatier, Laure; Sarchiapone, Lucia; Sebastià, Natividad; Sommer, Sylwester; Sun, Mingzhu; Suto, Yumiko; Terzoudi, Georgia; Trompier, Francois; Vral, Anne; Wilkins, Ruth; Zafiropoulos, Demetre; Wieser, Albrecht; Woda, Clemens; Wojcik, Andrzej

    2017-01-01

    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. 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 obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested.

  11. Accident risk. Chapter 5

    International Nuclear Information System (INIS)

    1978-01-01

    Following a historical introduction in which WASH-740, WASH-1400, Swedish, Finnish, Scandinavian, Netherlands and West German analyses are briefly presented, the concept of risk itself is discussed, distinguishing between objective and subjective aspects, and between voluntary and involuntary risk. Risk analysis is briefly described and an attempt made to define acceptable risk. In treating the safety philosophy of nuclear power plants the engineered safety precautions are presented. The numerical results of the analysis made for Norwegian conditions are presented and discussed. Underground siting, which has been much discussed in Norway is also treated, and emergency planning briefly discussed. The probability and consequences of core meltdown in a light water reactor are then discussed, and the possible faults leading to this, both internal, human errors and external impacts are analysed. The failure mechanisms in the containment building which could lead to the release of activity are discussed, followed by the dispersion of the activity and the health and economic consequences. The accidents at Wuergassen and Brown's Ferry are briefly described as examples. A brief discussion of nuclear insurance and nuclear law in Norway form the concluding sections. (JIW)

  12. Radioactivity control after Fukushima accident

    International Nuclear Information System (INIS)

    Vukovic, D.; Mitrovic, R.; Vicentijevic, M.; Pantelic, G.

    2011-01-01

    Fukushima nuclear accident has influence on more attention when radioactivity of fish were controlled. Sea fish, freshwater fish, fish products and fish flour were analysed ( 95 samples). All products were safe for use with radiation-hygienic aspects. [sr

  13. The Goiania accident - environmental survey

    International Nuclear Information System (INIS)

    Godoy, J.M.; Moreira, M.C.F.; Fonseca, E.S. da

    1997-01-01

    The survey methods applied during the Goiania accident could be considered complementary one to the other, and were able to give a clear picture about the contamination in the city to guide the further decontamination works. (author)

  14. Severe accident recriticality analyses (SARA)

    DEFF Research Database (Denmark)

    Frid, W.; Højerup, C.F.; Lindholm, I.

    2001-01-01

    with all three codes. The core initial and boundary conditions prior to recriticality have been studied with the severe accident codes SCDAP/RELAP5, MELCOR and MAAP4. The results of the analyses show that all three codes predict recriticality-both super-prompt power bursts and quasi steady-state power......Recriticality in a BWR during reflooding of an overheated partly degraded core, i.e. with relocated control rods, has been studied for a total loss of electric power accident scenario. In order to assess the impact of recriticality on reactor safety, including accident management strategies......, which results in large energy deposition in the fuel during power burst in some accident scenarios. The highest value, 418 cal g(-1), was obtained with SIMULATE-3K for an Oskarshamn 3 case with reflooding rate of 2000 kg s(-1). In most cases, however, the predicted energy deposition was smaller, below...

  15. Multidisciplinary accident investigation : volume 2

    Science.gov (United States)

    1976-05-01

    The Task II final report for 1974 of the Multidisciplinary Accident Investigation : Team of the Maryland Medical-Legal Foundation, Inc. is presented. This report describes some preliminary findings emanating from a series of comprehensive, multivaria...

  16. Multidisciplinary accident investigation : volume 1

    Science.gov (United States)

    1976-09-01

    The final report of the Multidisciplinary Accident Investigation Team of the Maryland Medical-Legal Foundation, Inc. is presented. The report describes the methodology, results, discussions, conclusions and recommendations pertaining to the investiga...

  17. [Early management of cerebrovascular accidents].

    Science.gov (United States)

    Libot, Jérômie; Guillon, Benoit

    2013-01-01

    A cerebrovascular accident requires urgent diagnosis and treatment.The management of a stroke must be early and adapted in order to improve the overall clinical outcome and lower the risk of mortality.

  18. HANARO thermal hydraulic accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul; Kim, Heon Il; Lee, Bo Yook; Lee, Sang Yong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    For the safety assessment of HANARO, accident analyses for the anticipated operational transients, accident scenarios and limiting accident scenarios were conducted. To do this, the commercial nuclear reactor system code. RELAP5/MOD2 was modified to RELAP5/KMRR; the thermal hydraulic correlations and the heat exchanger model was changed to incorporate HANARO characteristics. This report summarizes the RELAP/KMRR calculation results and the subchannel analyses results based on the RELAP/KMRR results. During the calculation, major concern was placed on the integrity of the fuel. For all the scenarios, the important accident analysis parameters, i.e., fuel centerline temperatures and the minimum critical heat flux ratio(MCHFR), satisfied safe design limits. It was verified, therefore, that the HANARO was safely designed. 21 tabs., 89 figs., 39 refs. (Author) .new.

  19. 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...

  20. Preparedness against nuclear power accidents

    International Nuclear Information System (INIS)

    1985-01-01

    This booklet contains information about the organization against nuclear power accidents, which exist in the four Swedish counties with nuclear power plants. It is aimed at classes 7-9 of the Swedish schools. (L.E.)

  1. Diverse topics in crystalline beams

    International Nuclear Information System (INIS)

    Wei, Jie; Draeseke, A.; Sessler, A.M.; Li, Xiao-Ping

    1995-01-01

    Equations of motion are presented, appropriate to interacting charged particles of diverse charge and mass, subject to the external forces produced by various kinds of magnetic fields and radio-frequency (rf) electric fields in storage rings. These equations are employed in the molecular dynamics simulations to study the properties of crystalline beams. The two necessary conditions for the formation and maintenance of crystalline beams are summarized. The transition from ID to 2D, and from 2D to 3D is explored, and the scaling behavior of the heating rates is discussed especially in the high temperature limit. The effectiveness of various cooling techniques in achieving crystalline states has been investigated. Crystalline beams made of two different species of ions via sympathetic cooling are presented, as well as circulating ''crystal balls'' bunched in all directions by magnetic focusing and rf field. By numerically reconstructing the original experimental conditions of the NAP-M ring, it is found that only at extremely low beam intensities, outside of the range of the original measurement, proton particles can form occasionally-passing disks. The proposed New ASTRID ring is shown to be suitable for the formation and maintenance of crystalline beams of all dimensions

  2. Two-phase flow patterns recognition and parameters estimation through natural circulation test loop image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, R.N.; Libardi, R.M.P.; Masotti, P.H.F.; Sabundjian, G.; Andrade, D.A.; Umbehaun, P.E.; Torres, W.M.; Conti, T.N.; Macedo, L.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Nuclear Engineering Center], e-mail: rnavarro@ipen.br

    2009-07-01

    Visualization of natural circulation test loop cycles is used to study two-phase flow patterns associated with phase transients and static instabilities of flow. Experimental studies on natural circulation flow were originally related to accidents and transient simulations relative to nuclear reactor systems with light water refrigeration. In this regime, fluid circulation is mainly caused by a driving force ('thermal head') which arises from density differences due to temperature gradient. Natural circulation phenomenon has been important to provide residual heat removal in cases of 'loss of pump power' or plant shutdown in nuclear power plant accidents. The new generation of compact nuclear reactors includes natural circulation of their refrigerant fluid as a security mechanism in their projects. Two-phase flow patterns have been studied for many decades, and the related instabilities have been object of special attention recently. Experimental facility is an all glass-made cylindrical tubes loop which contains about twelve demineralized water liters, a heat source by an electrical resistor immersion heater controlled by a Variac, and a helicoidal heat exchanger working as cold source. Data is obtained through thermo-pairs distributed over the loop and CCD cameras. Artificial intelligence based algorithms are used to improve (bubble) border detection and patterns recognition, in order to estimate and characterize, phase transitions patterns and correlate them with the periodic static instability (chugging) cycle observed in this circuit. Most of initial results show good agreement with previous numerical studies in this same facility. (author)

  3. Two-phase flow patterns recognition and parameters estimation through natural circulation test loop image analysis

    International Nuclear Information System (INIS)

    Mesquita, R.N.; Libardi, R.M.P.; Masotti, P.H.F.; Sabundjian, G.; Andrade, D.A.; Umbehaun, P.E.; Torres, W.M.; Conti, T.N.; Macedo, L.A.

    2009-01-01

    Visualization of natural circulation test loop cycles is used to study two-phase flow patterns associated with phase transients and static instabilities of flow. Experimental studies on natural circulation flow were originally related to accidents and transient simulations relative to nuclear reactor systems with light water refrigeration. In this regime, fluid circulation is mainly caused by a driving force ('thermal head') which arises from density differences due to temperature gradient. Natural circulation phenomenon has been important to provide residual heat removal in cases of 'loss of pump power' or plant shutdown in nuclear power plant accidents. The new generation of compact nuclear reactors includes natural circulation of their refrigerant fluid as a security mechanism in their projects. Two-phase flow patterns have been studied for many decades, and the related instabilities have been object of special attention recently. Experimental facility is an all glass-made cylindrical tubes loop which contains about twelve demineralized water liters, a heat source by an electrical resistor immersion heater controlled by a Variac, and a helicoidal heat exchanger working as cold source. Data is obtained through thermo-pairs distributed over the loop and CCD cameras. Artificial intelligence based algorithms are used to improve (bubble) border detection and patterns recognition, in order to estimate and characterize, phase transitions patterns and correlate them with the periodic static instability (chugging) cycle observed in this circuit. Most of initial results show good agreement with previous numerical studies in this same facility. (author)

  4. 49 CFR 195.50 - Reporting accidents.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Reporting accidents. 195.50 Section 195.50 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.50 Reporting accidents. An accident...

  5. 28 CFR 301.106 - Repetitious accidents.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Repetitious accidents. 301.106 Section 301.106 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE INMATE ACCIDENT COMPENSATION General § 301.106 Repetitious accidents. If an inmate worker is involved in successive accidents...

  6. 32 CFR 644.532 - Reporting accidents.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Reporting accidents. 644.532 Section 644.532... and Improvements § 644.532 Reporting accidents. Immediately upon receipt of information of an accident... that an accident has occurred, the former using command should be requested to send qualified explosive...

  7. 22 CFR 102.8 - Reporting accidents.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Reporting accidents. 102.8 Section 102.8... Accidents Abroad § 102.8 Reporting accidents. (a) To airline and Civil Aeronautics Administration... probably be the first to be informed of the accident, in which event he will be expected to report the...

  8. Prevention of radiation accidents and their consequences

    International Nuclear Information System (INIS)

    Khiski, J.

    1976-01-01

    Clearing out reasons for nuclear accidents enables to take effective measures to minimize them. The number of accidents in 1957 - 1974 is given. The frequency of accidents at various working places, while operating with various radioisotopes is presented. The analysis of accidents and the confirmation of these estimates can lead to the generalization of data and to the formulation of preventive measures [ru

  9. Accidents in making fireworks. Tapaturmat polttopuun teossa

    Energy Technology Data Exchange (ETDEWEB)

    Solmio, H

    1991-01-01

    The accidents and the trends in the number of accidents and their causes were analyzed in a study conducted by the Forestry Department of the Work Efficiency Institute. The study was funded by the Finnish Agricultural Enterpreneurs' Pension Fund (MELA). The study material was selected from MELA's accident stage work and cause code. Altogether, the material comprised the following accidents that occurred while making and using firewood: 671 accidents in 1987 and 596 accidents in 1988. The amount of accidents caused by the working environment and hand tools was clearly higher in 1987 than in 1988. The number of accidents occurred while chopping wood was 20 % higher in 1987 than in 1988. April was the most accident-prone month both in 1987 and in 1988. Chopping of firewood was the most dangerous work stage in terms of the number of accidents. In 1988, the number of accidents in chopping firewood was 336, in sawing using circular saw 97 cases and other mechanized chopping led to 93 accidents. Heating with wood caused 33 accidents. In 1988 there were 10 (2 %) accidents involving loss of limbs and 9 of them occurred in the mechanized chopping of firewood. Nine accidents of these involved the loss of one or more fingers. Serious accidents, leading to inability to work for more than 3 months, were most frequent in chopping and in storing firewood.

  10. Accidents at nuclear power plants

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The accidents which accurred at Wuergassen, Browns Ferry and Three Mile Island are each briefly described and discussed. The last is naturally treated in much more detail than the first two. Damage to the fuel elements is briefly considered and the release of fission products, radiation doses to the population and their expected consequences are discussed. The accidents are evaluated and related to risk evaluations, especially in WASH-1400. (JIW)

  11. JCO criticality accident termination operation

    OpenAIRE

    金盛 正至

    2010-01-01

    In 2001, we summarized the circumstances surrounding termination of the JCO criticality accident based on testimony in the Mito District Court on December 17, 2001. JCO was the company for uranium fuels production in Japan. That document was assembled based on actual testimony in the belief that a description of the work involved in termination of the accident would be useful in some way for preventing nuclear disasters in the future. This year is the tenth year of the JCO criticality acciden...

  12. Nuclear laws and radiologic accidents

    International Nuclear Information System (INIS)

    Frois, Fernanda

    1997-01-01

    Some aspects of the nuclear activities in Brazil, specially concerning the Goiania s accident are demonstrated using concepts from environmental and nuclear law. Nuclear and environmental competence, the impossibility of the states of making regional laws, as the lack of regulation about the nuclear waste, are discussed. The situation of Goiania when the accident happened, the present situation of the victims and the nuclear waste provisionally stored in Abadia de Goias is reported

  13. Spallation Neutron Source Accident Terms for Environmental Impact Statement Input

    Energy Technology Data Exchange (ETDEWEB)

    Devore, J.R.; Harrington, R.M.

    1998-08-01

    This report is about accidents with the potential to release radioactive materials into the environment surrounding the Spallation Neutron Source (SNS). As shown in Chap. 2, the inventories of radioactivity at the SNS are dominated by the target facility. Source terms for a wide range of target facility accidents, from anticipated events to worst-case beyond-design-basis events, are provided in Chaps. 3 and 4. The most important criterion applied to these accident source terms is that they should not underestimate potential release. Therefore, conservative methodology was employed for the release estimates. Although the source terms are very conservative, excessive conservatism has been avoided by basing the releases on physical principles. Since it is envisioned that the SNS facility may eventually (after about 10 years) be expanded and modified to support a 4-MW proton beam operational capability, the source terms estimated in this report are applicable to a 4-MW operating proton beam power unless otherwise specified. This is bounding with regard to the 1-MW facility that will be built and operated initially. See further discussion below in Sect. 1.2.

  14. Development and application of a radioactivity evaluation technique the to obtain radiation exposure dose of radioactivity evaluation technique when a severe accident occurs in the a power station of a severe accident. Accident management guidelines of knowledge-based maintenance

    International Nuclear Information System (INIS)

    Kawasaki, Ikuo; Yoshida, Yoshitaka

    2013-01-01

    As a One of the lessons learned from the nuclear accident at the Fukushima Daiichi Nuclear Power Stations of Tokyo Electric Power Company, the was the need for improvement of accident management guidelines is required. In this report study, we developed and applied a dose evaluation technique to evaluated the radiation dose in a nuclear power plant assuming three conditions: employees were evacuation evacuated at the time of a severe accident occurrence; operators carried out the accident management operation; of the operators, and the repair work was carried out for of the trouble damaged apparatuses in a the nuclear power plant using a dose evaluation system. The following knowledge findings were obtained and should to be reflected to in the knowledge base of the guidelines was obtained. (1) By making clearly identifying an areas beforehand becoming the that would receive high radiation doses at the time of a severe accident definitely beforehand, we can employees can be moved to the evacuation places through an areas having of low dose rate and it is also known it how much we long employees can safely stay in the evacuation places. (2) When they circulate CV containment vessel recirculation sump water is recirculated by for the accident management operation and the restoration of safety in the facilities, because the plumbing piping and the apparatuses become radioactive radioactivity sources, the dose evaluation of the shortest access route and detour access routes with should be made for effective the accident management operation is effective. Because the area where a dose rate rises changes which as safety apparatuses are restored, in consideration of a plant state, it is necessary to judge the rightness or wrongness of the work continuation from the spot radioactive dose of the actual apparatus area, with based on precedence of the need to restore with precedence, and to choose a system to be used for accident management. (author)

  15. The IAEA Accident Management Programme

    International Nuclear Information System (INIS)

    Kabanov, L.; Jankowski, M.; Mauersberger, H.

    1993-01-01

    Accident prevention and mitigation programmes and the Emergency Response System (ERS) are important elements of the Agency's activities in the area of nuclear power plant (NPP) safety. Safety Codes and Guides on siting, design, quality assurance and the operation of NPPs have been produced and are used by NPP operating organizations. Nuclear safety evaluation services are provided by the IAEA. The Emergency Response System and the International Nuclear Event Scale (INES) have been developed. The framework for the development of an accident management programme has been set up. The main goal is to develop an Accident Management Manual to provide a systematic, structured approach to the development and implementation of an accident management programme at NPPs. An outline of the Manual has been distributed and the first draft is available. The component parts are: Co-ordinated research programmes (CRPs) on severe accident management and containment behaviour; the use of vulnerability analysis; mitigation of the effects of hydrogen, and generic symptom oriented emergency operating procedures. The IAEA provides guidance by the dissemination of information on methods for accident management; collates information on approaches in this field in different organizations and countries; and arranges exchange of experience and the promulgation of knowledge through the training of NPP managers and senior technical staff. (orig.)

  16. [Fatal occupational accidents in Lombardy].

    Science.gov (United States)

    Pianosi, G

    1995-01-01

    All fatal occupational accidents compensated in Lombardy from 1984 to 1989 were analyzed (1259 cases): significant differences between geographical distribution of fatal occupational accidents and workers were observed. Males accounted for about 95% of fatalities; an excess of cases was shown in both young and elderly workers. Death was the consequence of injuries involving most frequently the head, thorax and spinal cord. An excess of fatalities was observed in agriculture and, at a lower level, in manufacturing industries; small enterprises were involved in approximately 25% of fatalities occurring in the manufacturing industries and services. Employers were the victims of fatal accidents in 50% of cases in agriculture and in 70% of cases in craft industries. Construction, agriculture and transport accounted for about 50% of all fatalities. About 50% of fatal occupational accidents were related to vehicle use: the victim was the driver in the majority of cases, sometimes the victim was run over by a vehicle or fell from a vehicle. The results agree with some previous observations (e.g.: sex and age distribution; construction, agriculture and transport as working activities at high accident risk); but some original observations have emerged, in particular about the frequency of employers as victims and the role of vehicles in the genesis of fatal occupational accidents. If further studies confirm these latter observations, important developments could follow in preventive action design and implementation.

  17. CARNSORE: Hypothetical reactor accident study

    International Nuclear Information System (INIS)

    Walmod-Larsen, O.; Jensen, N.O.; Kristensen, L.; Meide, A.; Nedergaard, K.L.; Nielsen, F.; Lundtang Petersen, E.; Petersen, T.; Thykier-Nielsen, S.

    1984-06-01

    Two types of design-basis accident and a series of hypothetical core-melt accidents to a 600 MWe reactor are described and their consequences assessed. The PLUCON 2 model was used to calculate the consequences which are presented in terms of individual and collective doses, as well as early and late health consequences. The site proposed for the nucelar power station is Carnsore Point, County Wexford, south-east Ireland. The release fractions for the accidents described are those given in WASH-1400. The analyses are based on the resident population as given in the 1979 census and on 20 years of data from the meteorological stations at Rosslare Harbour, 8.5 km north of the site. The consequences of one of the hypothetical core-melt accidents are described in detail in a meteorological parametric study. Likewise the consequences of the worst conceivable combination of situations are described. Finally, the release fraction in one accident is varied and the consequences of a proposed, more probable ''Class 9 accident'' are presented. (author)

  18. The IAEA Accident Management Programme

    Energy Technology Data Exchange (ETDEWEB)

    Kabanov, L.; Jankowski, M.; Mauersberger, H. (International Atomic Energy Agency, Vienna (Austria))

    1993-02-01

    Accident prevention and mitigation programmes and the Emergency Response System (ERS) are important elements of the Agency's activities in the area of nuclear power plant (NPP) safety. Safety Codes and Guides on siting, design, quality assurance and the operation of NPPs have been produced and are used by NPP operating organizations. Nuclear safety evaluation services are provided by the IAEA. The Emergency Response System and the International Nuclear Event Scale (INES) have been developed. The framework for the development of an accident management programme has been set up. The main goal is to develop an Accident Management Manual to provide a systematic, structured approach to the development and implementation of an accident management programme at NPPs. An outline of the Manual has been distributed and the first draft is available. The component parts are: Co-ordinated research programmes (CRPs) on severe accident management and containment behaviour; the use of vulnerability analysis; mitigation of the effects of hydrogen, and generic symptom oriented emergency operating procedures. The IAEA provides guidance by the dissemination of information on methods for accident management; collates information on approaches in this field in different organizations and countries; and arranges exchange of experience and the promulgation of knowledge through the training of NPP managers and senior technical staff. (orig.).

  19. Reactor accidents and the environment

    International Nuclear Information System (INIS)

    Beattie, J.R.; Griffiths, R.F.; Kaiser, G.D.; Kinchin, G.H.

    1978-01-01

    This is a condensed version of a paper, entitled 'The Environmental Impact of Radioactive Releases from Accidents in Nuclear Power Reactors', by the authors, presented to the Nuclear Energy Panel of the International Atomic Energy Agency/United Nations Environmental Programme. Headings include - Effects of ionising radiation on man; number of deaths expected from leukaemia and other cancers; risk estimates for incidence of benign nodules and thyroid cancer; maximum permissible levels and emergency levels of radiation and radioactivity; ICRP recommended dose limits for members of the general public; atmospheric dispersion and modelling; ICRP emergency reference levels for 1 131 , Cs 137 , Ru 106 and Sr 90 ; environmental consequences of accidental releases from nuclear power reactors; environmental impact of accidents to Magnox gas-cooled reactors; environmental impact of accidents to advanced gas-cooled reactors; environmental impact of accidents to fast reactors; and nature of risks. consequences are examined in terms of early and late biological effects on man, and contamination of land areas. Serious accidents are of low probability of occurrence, and the risk of accidents to nuclear power reactors is estimated to be very small. 43 references. (U.K.)

  20. Learning from nuclear accident experience

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1984-01-01

    Statistical procedures are developed to estimate accident occurrence rates from historical event records, to predict future rates and trends, and to estimate the accuracy of the rate estimates and predictions. Maximum likelihood estimation is applied to several learning models, and results are compared to earlier graphical and analytical estimates. The models are based on (1) the cumulative number of operating years, (2) the cumulative number of plants built, and (3) accidents (explicitly), with the accident rate distinctly different before and after an accident. The statistical accuracies of the parameters estimated are obtained in analytical form using the Fisher information matrix. Using data on core damage accidents in electricity producing plants, it is estimated that the probability for a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the equivalent frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year, partly due to the increasing population of plants. 10 references, 7 figures, 2 tables

  1. JAERI's activities in JCO accident

    International Nuclear Information System (INIS)

    2000-09-01

    The Japan Atomic Energy Research Institute (JAERI) was actively involved in a variety of technical supports and cooperative activities, such as advice on terminating the criticality condition, contamination checks of the residents and consultation services for the residents, as emergency response actions to the criticality accident at the uranium processing facility operated by the JCO Co. Ltd., which occurred on September 30, 1999. These activities were carried out in collaborative ways by the JAERI staff from the Tokai Research Establishment, Naka Fusion Research Establishment, Oarai Research Establishment, and Headquarter Office in Tokyo. As well, the JAERI was engaged in the post-accident activities such as identification of accident causes, analyses of the criticality accident, and dose assessment of exposed residents, to support the Headquarter for Accident Countermeasures of the Science and Technology Agency (STA), the Accident Investigation Committee and the Health Control Committee of the Nuclear Safety Commission of Japan (NSC). This report compiles the activities, that the JAERI has conducted to date, including the discussions on measures for terminating the criticality condition, evaluation of the fission number, radiation monitoring in the environment, dose assessment, analyses of criticality dynamics. (author)

  2. Nuclear fuel cycle facility accident analysis handbook

    International Nuclear Information System (INIS)

    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

  3. Application of Melcor code for the calculo of TMLB sequence in PWR with natural circulating into the vessel

    International Nuclear Information System (INIS)

    Marten-Fuertes, F.

    1995-01-01

    The use of computer codes to analyze the phenomena of severe accidents is very important to take decisions in Nuclear Safety. This paper presents the MELCOR code used to calculate the TMLB sequence of PWR with natural circulation into the vessels. The main goal of this code is its application for the PSA (probabilistic safety analysis)

  4. Radiological accidents: education for prevention and confrontation

    International Nuclear Information System (INIS)

    Cardenas Herrera, Juan; Fernandez Gomez, Isis Maria

    2008-01-01

    The purpose of this work is to train and inform on radiological accidents as a preventive measure to improve the people life quality. Radiological accidents are part of the events of technological origin which are composed of nuclear and radiological accidents. As a notable figure is determined that there have been 423 radiological accidents from 1944 to 2005 and among the causes prevail industrial accidents, by irradiations, medical accidents and of laboratories, among others. Latin American countries such as Argentina, Brazil, Mexico and Peru are some where most accidents have occurred by radioactivity. The radiological accidents can have sociological, environmental, economic, social and political consequences. In addition, there are scenarios of potential nuclear accidents and in them the potential human consequences. Also, the importance of the organization and planning in a nuclear emergency is highlighted. Finally, the experience that Cuba has lived on the subject of radiological accidents is described [es

  5. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model\\'s winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow. Key Points Sinking occurs in a narrow boundary layer along the eastern boundary Surface western boundary current switches into an eastern boundary current Water exchange in the Strait of Bab el Mandeb is not hydraulically controlled © 2014. American Geophysical Union. All Rights Reserved.

  6. A Phase Space Monitoring of Injected Beam of J-PARC MR

    Science.gov (United States)

    Hatakeyama, Shuichiro; Toyama, Takeshi

    Beam power of J-PARC MR (30 GeV Proton Synchrotron Main Ring) has been improved since 2008 and now achieved over 200 kW for the user operation. A part of beam loss is localized at the beam injection phase so it is important to monitor the beam bunch behavior in the transverse direction. In this paper it is described the method how to measure the position and momentum for each injected beam bunch using Beam Position Monitors (BPMs). It is also mentioned some implementation of an operator's interface (OPI) to display the plots of injected and circulating beam bunches in phase space coordinate.

  7. Accident tolerant fuel analysis

    International Nuclear Information System (INIS)

    2014-01-01

    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

  8. The Invertibility, Explicit Determinants, and Inverses of Circulant and Left Circulant and g-Circulant Matrices Involving Any Continuous Fibonacci and Lucas Numbers

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available Circulant matrices play an important role in solving delay differential equations. In this paper, circulant type matrices including the circulant and left circulant and g-circulant matrices with any continuous Fibonacci and Lucas numbers are considered. Firstly, the invertibility of the circulant matrix is discussed and the explicit determinant and the inverse matrices by constructing the transformation matrices are presented. Furthermore, the invertibility of the left circulant and g-circulant matrices is also studied. We obtain the explicit determinants and the inverse matrices of the left circulant and g-circulant matrices by utilizing the relationship between left circulant, g-circulant matrices and circulant matrix, respectively.

  9. Main circulator design features for HTR 100, HTR 500 and space heating plants

    International Nuclear Information System (INIS)

    Engel, J.; Glass, D.

    1988-01-01

    All design alternatives for modern high-temperature reactors have a common circulator concept: It is based on a vertical shaft design with a flying impeller. The circulators are equipped with active magnetic bearings and are driven by induction motors connected to variable-speed static converters. Due to their multiple functions during normal reactor operation and under accident conditions, extremely high requirements are made to safety-relevant circulators, since with the reactor pressurized as well as under depressurized conditions specified delivery heads and flow rates have to be ensured. The use of active magnetic bearings permits to obtain maintenance-free operation and functional safety to an extent which had not been achieved before. Magnetic bearings are therefore provided for the total range including primary gas circulators of a drive power of several MW as well as circulators for helium loops of reactor auxiliary systems. The essential feature for using active magnetic bearings is the retainer bearing technology, preventing contact between rotor and static circulator parts upon unintended deenergisation of the magnets. Results of current experiments are reported. Another aspect to be considered for reliable long-term operation for several decades is the effect of rotor dynamics. The various natural frequencies resulting from torsion and bending modes in view of a drive by a frequency-controlled induction motor have to be considered as well as the specific characteristics of the active magnetic bearings. Special attention has to be directed to the internal cooling loop so as to ensure that reactor temperature excursions in the event of deviation from normal operation can be overcome without damage. For circulator components exposed to temperature fields the design characteristics are determined by combining experimental and analytical methods. The coordination of all component parts is currently being optimized on a prototype circulator whose detailed

  10. Comparison of auxiliary feedwater and EDRS operation during natural circulation of MRX

    International Nuclear Information System (INIS)

    Kim, Jae Hak; Park, Goon Cherl

    1997-01-01

    The MRX is an integral type ship reactor with 100 MWt power, which is designed by Japan Atomic Energy Research Institute. It is characterized by integral type PWR, in-vessel type control rod drive mechanism, water-filled containment vessel and passive decay heat removal system. Marine reactor should have high passive safety. Therefore, in this study, we simulated the loss of flow accident to verify the passive decay heat removal by natural circulation using RETRAN-03 code. auxiliary feed water systems are used for decay heat removal mechanism and results are compared with the loss of flow accident analysis using emergency decay heat removal system by JAERI. Results are very similar to case of EDRS 1 loop operation in JAERI analysis and decay heat is successfully removed by natural circulation

  11. Study on operational aspect of natural circulation HLMC reactor (1)

    International Nuclear Information System (INIS)

    Sienicki, J.J.; Cahalan, J.E.; Spencer, B.W.

    2000-08-01

    The concept of a heavy liquid metal cooled fast reactor that achieves 100% natural circulation heat removal from the core has the potential to attain improved cost competitiveness through extreme simplification, proliferation resistance, and heightened passive safety. The concept offers the potential for simplifications in plant control strategies wherein inherent reactor feedbacks may restore balance between energy release and heat removal from the reactor during operation as well as providing passive reactivity shutdown in the event of transients involving failure to scram. This study was initiated to evaluate the operational characteristics of the 100% natural circulation reactor under normal and transient states using a plant dynamics analysis computer code and to seek design and operational optimization of the concept. In the current Phase I of the project, the stage for the overall study has been prepared. A coupled thermal hydraulics-kinetics plant dynamics analysis code has been developed/modified that has the capabilities to calculate operational and accident transients. Code input has been prepared for the heavy liquid metal cooled natural circulation reactor concept. A preliminary analysis using the plant dynamics code and its input to calculate three illustrative cases relevant to initial startup, shutdown following long-term operation, and change in turbine load demonstrates the capability to analyze typical transient cases. (author)

  12. The cost of nuclear accidents

    International Nuclear Information System (INIS)

    2015-01-01

    Proposed by a technical section of the SFEN, and based on a meeting with representatives of different organisations (OECD-NEA, IRSN, EDF, and European Nuclear Energy Forum), this publication addresses the economic consequences of a severe accident (level 6 or 7) within an electricity producing nuclear power plant. Such an assessment essentially relies on three pillars: release of radio-elements outside the reactor, the scenario of induced consequences, and the method of economic quantification. After a recall and a comment of safety arrangements, and of the generally admitted probability of such an accident, this document notices that several actors are concerned by nuclear energy and are trying to assess accident costs. The issue of how to assess a cost (or costs) of a nuclear accident is discussed: there are in fact several types of costs and consequences. Thus, some costs can be rather precisely quantified when some others can be difficult to assess or with uncertainty. The relevance of some cost categories appears to be a matter of discussion and one must not forget that consequences can occur on a long term. The need for methodological advances is outlined and three categories of technical objectives are identified for the assessment (efficiency of safety measures to be put forward to mitigate the risk via a better accident management, compensation of victims and nuclear civil responsibility, and comparison of electricity production sectors and assessment of externalisation to guide public choices). It is outlined that the impact of accidents depend on several factors, that the most efficient mean to limit consequences of accidents is of course to limit radioactive emissions

  13. Lessons Learnt from Past Incidents and Accidents in Radiation Oncology.

    Science.gov (United States)

    Knöös, T

    2017-09-01

    The purpose of this report is to review and compile what have been and can be learnt from incidents and accidents in radiation oncology, especially in external beam and brachytherapy. Some major accidents from the last 20 years will be discussed. The relationship between major events and minor or so-called near misses is mentioned, leading to the next topic of exploring the knowledge hidden among them. The main lessons learnt from the discussion here and elsewhere are that a well-functioning and safe radiotherapy department should help staff to work with awareness and alertness and that documentation and procedures should be in place and known by everyone. It also requires that trained and educated staff with the required competences are in place and, finally, functions and responsibilities are defined and well known. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Laser anemometry measurements of natural circulation flow in a scale model PWR system

    International Nuclear Information System (INIS)

    Kadambi, J.R.; Schneider, S.J.

    1990-01-01

    This paper reports on experimental studies conducted to investigate the natural circulation of a single-phase fluid in a scale model pressurized water reactor system during a postulated degraded core accident. A half-section of a 1/7 scale model with a plexiglass adiabatic window was used. Water and sulfurhexafluoride (SF 6 ) were used as the fluid. Laser-Doppler anemometry (LDA) was used in marking the velocity measurements along the center plane of the model at five elevations

  15. Proper Sizing of Circulation Pumps

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Nørgaard, Jørgen

    2007-01-01

    The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust, but the r......The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust...

  16. Electron beam cooling by laser

    CERN Document Server

    Urakawa, J; Terunuma, N; Taniguchi, T; Yamazaki, Y; Hirano, K; Nomura, M; Sakai, I; Takano, M; Sasao, N; Honda, Y; Noda, A; Bulyak, E; Gladkikh, P; Mystykov, A; Zelinsky, A; Zimmermann, Frank

    2004-01-01

    In 1997, Z.Huang and R.Ruth proposed a compact laser-electron storage ring (LESR) for electron beam cooling or x-ray generation. Because the laser-wire monitor in the ATF storage ring has worked well and demonstrated the achievement of the world's smallest transverse emittance for a circulating electron beam, we have started the design of a small storage ring with about 10 m circumference and the development of basic technologies for the LESR. In this paper, we describe the design and experimental results of pulse stacking in a 42-cm long optical cavity. Since our primary purpose is demonstrating the proof-of-principle of the LESR, we will then discuss the future experimental plan at the KEK-ATF for the generation of high average-brilliance gamma-rays.

  17. Accident prevention in power plants

    International Nuclear Information System (INIS)

    Steyrer, H.

    Large thermal power plants are insured to a great extent at the Industrial Injuries Insurance Institute of Instrument and Electric Engineering. Approximately 4800 employees are registered. The accident frequency according to an evaluation over 12 months lies around 79.8 per year and 1000 employees in fossil-fired power plants, around 34.1 per year and 1000 employees in nuclear power plants, as in nuclear power plants coal handling and ash removal are excluded. Injuries due to radiation were not registered. The crucial points of accidents are mechanical injuries received on solid, sharp-edged and pointed objects (fossil-fired power plants 28.6%, nuclear power plants 41.5%), stumbling, twisting or slipping (fossil-fired power plants 21.8%, nuclear power plants 19.5%) and injuries due to moving machine parts (only nuclear power plants 12.2%). However, accidents due to burns or scalds obtain with 4.2% and less a lower portion than expected. The accident statistics can explain this fact in a way that the typical power plant accident does not exist. (orig./GL) [de

  18. 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. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. A CANDU Severe Accident Analysis

    International Nuclear Information System (INIS)

    Negut, Gheorghe; Catana, Alexandru; Prisecaru, Ilie

    2006-01-01

    As interest in severe accident studies has increased in the last years, we have developed a set of simple models to analyze severe accidents for CANDU reactors that should be integrated in the EU codes. The CANDU600 reactor uses natural uranium fuel and heavy water (D2O) as both moderator and coolant, with the moderator and coolant in separate systems. We chose to analyze accident development for a LOCA with simultaneous loss of moderator cooling and the loss of emergency core cooling system (ECCS). This type of accident is likely to modify the reactor geometry and will lead to a severe accident development. When the coolant temperatures inside a pressure tube reaches 10000 deg C, a contact between pressure tube and calandria tube occurs and the residual heat is transferred to the moderator. Due to the lack of cooling, the moderator eventually begins to boil and is expelled, through the calandria vessel relief ducts, into the containment. Therefore the calandria tubes (fuel channels) will be uncovered, then will disintegrate and fall down to the calandria vessel bottom. After all the quantity of moderator is vaporized and expelled, the debris will heat up and eventually boil. The heat accumulated in the molten debris will be transferred through the calandria vessel wall to the shield tank water, which normally surrounds the calandria vessel. The phenomena described above are modelled, analyzed and compared with the existing data. The results are encouraging. (authors)

  20. Accident knowledge and emergency management

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, B; Groenberg, C D

    1997-03-01

    The report contains an overall frame for transformation of knowledge and experience from risk analysis to emergency education. An accident model has been developed to describe the emergency situation. A key concept of this model is uncontrolled flow of energy (UFOE), essential elements are the state, location and movement of the energy (and mass). A UFOE can be considered as the driving force of an accident, e.g., an explosion, a fire, a release of heavy gases. As long as the energy is confined, i.e. the location and movement of the energy are under control, the situation is safe, but loss of confinement will create a hazardous situation that may develop into an accident. A domain model has been developed for representing accident and emergency scenarios occurring in society. The domain model uses three main categories: status, context and objectives. A domain is a group of activities with allied goals and elements and ten specific domains have been investigated: process plant, storage, nuclear power plant, energy distribution, marine transport of goods, marine transport of people, aviation, transport by road, transport by rail and natural disasters. Totally 25 accident cases were consulted and information was extracted for filling into the schematic representations with two to four cases pr. specific domain. (au) 41 tabs., 8 ills.; 79 refs.

  1. The radiological accident in Cochabamba

    International Nuclear Information System (INIS)

    2004-07-01

    In April 2002 an accident involving an industrial radiography source containing 192 Ir occurred in Cochabamba, Bolivia, some 400 km from the capital, La Paz. A faulty radiography source container had been sent back to the headquarters of the company concerned in La Paz together with other equipment as cargo on a passenger bus. This gave rise to a potential for serious exposure for the bus passengers as well as for the company employees who were using and transporting the source. The Government of Bolivia requested the assistance of the IAEA under the terms of the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency. The IAEA in response assembled and sent to Bolivia a team composed of senior radiation safety experts and radiation pathology experts from Brazil, the United Kingdom and the IAEA to investigate the accident. The IAEA is grateful to the Government of Bolivia for the opportunity to report on this accident in order to disseminate the valuable lessons learned and help prevent similar accidents in the future

  2. Accident knowledge and emergency management

    International Nuclear Information System (INIS)

    Rasmussen, B.; Groenberg, C.D.

    1997-03-01

    The report contains an overall frame for transformation of knowledge and experience from risk analysis to emergency education. An accident model has been developed to describe the emergency situation. A key concept of this model is uncontrolled flow of energy (UFOE), essential elements are the state, location and movement of the energy (and mass). A UFOE can be considered as the driving force of an accident, e.g., an explosion, a fire, a release of heavy gases. As long as the energy is confined, i.e. the location and movement of the energy are under control, the situation is safe, but loss of confinement will create a hazardous situation that may develop into an accident. A domain model has been developed for representing accident and emergency scenarios occurring in society. The domain model uses three main categories: status, context and objectives. A domain is a group of activities with allied goals and elements and ten specific domains have been investigated: process plant, storage, nuclear power plant, energy distribution, marine transport of goods, marine transport of people, aviation, transport by road, transport by rail and natural disasters. Totally 25 accident cases were consulted and information was extracted for filling into the schematic representations with two to four cases pr. specific domain. (au) 41 tabs., 8 ills.; 79 refs

  3. 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.

  4. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    The beam diagnostic components for both the transfer and the high-energy beamlines perform well except for some of the scanners whose noise pick-up has become a problem, especially at low beam intensities. This noise pick-up is primarily due to deterioration of the bearings in the scanner. At some locations in the high-energy beamlines, scanners were replaced by harps as the scanners proved to be practically useless for the low-intensity beams required in the experimental areas. The slits in the low-energy beamline, which are not water-cooled, have to be repaired at regular intervals because of vacuum leaks. Overheating causes the ceramic feedthroughs to deteriorate resulting in the vacuum leaks. Water-cooled slits have been ordered to replace the existing slits which will later be used in the beamlines associated with the second injector cyclotron SPC2. The current-measurement system will be slightly modified and should then be much more reliable. 3 figs

  5. Preliminary accident analysis of Flexblue® underwater reactor

    Directory of Open Access Journals (Sweden)

    Haratyk Geoffrey

    2015-01-01

    Full Text Available Flexblue® is a subsea-based, transportable, small modular reactor delivering 160 MWe. Immersion provides the reactor with an infinite heat sink – the ocean – around the metallic hull. The reference design includes a loop-type PWR with two horizontal steam generators. The safety systems are designed to operate passively; safety functions are fulfilled without operator action and external electrical input. Residual heat is removed through four natural circulation loops: two primary heat exchangers immersed in safety tanks cooled by seawater and two emergency condensers immersed in seawater. In case of a primary piping break, a two-train safety injection system is actuated. Each train includes a core makeup tank, an accumulator and a safety tank at low pressure. To assess the capability of these features to remove residual heat, the reactor and its safety systems have been modelled using thermal-hydraulics code ATHLET with conservative assumptions. The results of simulated transients for three typical PWR accidents are presented: a turbine trip with station blackout, a large break loss of coolant accident and a small break loss of coolant accident. The analyses show that the safety criteria are respected and that the reactor quickly reaches a safe shutdown state without operator action and external power.

  6. Interaction of Macro-particles with LHC proton beam

    CERN Document Server

    Zimmermann, F; Xagkoni, A

    2010-01-01

    We study the interaction of macro-particles residing inside the LHC vacuum chamber, e.g. soot or thermalinsulation fragments, with the circulating LHC proton beam. The coupled equations governing the motion and charging rate of metallic or dielectric micron-size macroparticles are solved numerically to determine the time spent by such “dust” particles close to the path of the beam as well as the resulting proton-beam losses, which could lead to a quench of superconducting magnets and, thereby, to a premature beam abort.

  7. The Three Mile Island accident

    International Nuclear Information System (INIS)

    Zebroski, E.L.

    1980-01-01

    It is important that the causes of this accident (and other, similar accidents but with less dramatic consequences) are completely understood and that the role of every contributing factor is exactly determined in order to discuss modifications and to judge their relative importance and schedule in an objective way. If the role of the various factors contributing to an accident is not fully understood, there will always be a 'mythology' of prejudiced and highly simplified assumptions. The experience of failure analysis shows that the causes first assumed are hardly ever the right ones, and that in some major and complex cases even the second or third generation of assumed causes is wrong. (orig.) [de

  8. Severe accident management guidelines tool

    International Nuclear Information System (INIS)

    Gutierrez Varela, Javier; Tanarro Onrubia, Augustin; Martinez Fanegas, Rafael

    2014-01-01

    Severe Accident is addressed by means of a great number of documents such as guidelines, calculation aids and diagnostic trees. The response methodology often requires the use of several documents at the same time while Technical Support Centre members need to assess the appropriate set of equipment within the adequate mitigation strategies. In order to facilitate the response, TECNATOM has developed SAMG TOOL, initially named GGAS TOOL, which is an easy to use computer program that clearly improves and accelerates the severe accident management. The software is designed with powerful features that allow the users to focus on the decision-making process. Consequently, SAMG TOOL significantly improves the severe accident training, ensuring a better response under a real situation. The software is already installed in several Spanish Nuclear Power Plants and trainees claim that the methodology can be followed easier with it, especially because guidelines, calculation aids, equipment information and strategies availability can be accessed immediately (authors)

  9. Severe accident simulation at Olkiuoto

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkonen, H.; Saarenpaeae, T. [Teollisuuden Voima Oy (TVO), Olkiluoto (Finland); Cliff Po, L.C. [Micro-Simulation Technology, Montville, NJ (United States)

    1995-09-01

    A personal computer-based simulator was developed for the Olkiluoto nuclear plant in Finland for training in severe accident management. The generic software PCTRAN was expanded to model the plant-specific features of the ABB Atom designed BWR including its containment over-pressure protection and filtered vent systems. Scenarios including core heat-up, hydrogen generation, core melt and vessel penetration were developed in this work. Radiation leakage paths and dose rate distribution are presented graphically for operator use in diagnosis and mitigation of accidents. Operating on an graphically for operator use in diagnosis and mitigation of accidents. Operating on an 486 DX2-66, PCTRAN-TVO achieves a speed about 15 times faster than real-time. A convenient and user-friendly graphic interface allows full interactive control. In this paper a review of the component models and verification runs are presented.

  10. Containment integrity analysis under accidents

    International Nuclear Information System (INIS)

    Lin Chengge; Zhao Ruichang; Liu Zhitao

    2010-01-01

    Containment integrity analyses for current nuclear power plants (NPPs) mainly focus on the internal pressure caused by design basis accidents (DBAs). In addition to the analyses of containment pressure response caused by DBAs, the behavior of containment during severe accidents (SAs) are also evaluated for AP1000 NPP. Since the conservatism remains in the assumptions,boundary conditions and codes, margin of the results of containment integrity analyses may be overestimated. Along with the improvements of the knowledge to the phenomena and process of relevant accidents, the margin overrated can be appropriately reduced by using the best estimate codes combined with the uncertainty methods, which could be beneficial to the containment design and construction of large passive plants (LPP) in China. (authors)

  11. Patient treatment in radiation accidents

    International Nuclear Information System (INIS)

    Tanum, G.; Bruland, Oe.S.; Hjelle, D.; Reitan, J.B.

    1999-01-01

    Accidental human injury due to ionizing radiation is rare. Industrial accidents are comparatively the most common. Life saving procedures should always have priority to any concern about radiation injury or contamination. The personal risks for emergency medial personnel is negligible when simple measures are taken. Repeated clinical examinations and blood lymphocyte counts should be performed on all patients with suspected radiation injury to allow a diagnosis. The radiation syndrome develops within days or weeks depending on total radiation dose, dose rate and dose distribution. Damage to the bone marrow and gut are the most important. Local radiation injuries to the hands are common in industrial accidents. The Norwegian Radiation Protection Authority should always be called when a potential ionizing radiation accident takes place within Norway

  12. Action in case of accident

    International Nuclear Information System (INIS)

    Matijasic, A.

    1961-01-01

    This report describes the radiation accidents that occurred in the Institute, causes of these accidents and actions undertaken to eliminate the consequences as well as losses and cost estimated. The accidents were as follows: explosion of the uranium mixture; contamination due to spill of P 32 ; contamination due to spilling of Sr 89 solution; spilling of I 131 in the cell for radioactive iodine production; contamination of the floor by P 32 ; contamination of the platform below the water shield at the RA reactor and during cleaning of the vertical channels; contamination due to spilling of Sr 89 solution; contamination of cells for I 131 and P 32 and the cell for isotopes packaging; contamination of the floor by non-identified isotope mixture; contamination of the cell for I'1 31 production by irradiated Tl powder; contamination by La 140 powder; contamination of the cell for isotopes packaging

  13. Nuclear law and radiological accidents

    International Nuclear Information System (INIS)

    Frois, F.

    1998-01-01

    Nuclear activities in Brazil, and particularly the radiological accident of Goiania, are examined in the light of the environmental and nuclear laws of Brazil and the issue of responsibility. The absence of legislation covering radioactive wastes as well as the restrictions on Brazilian States to issue regulations covering nuclear activities are reviewed. The radiological accident and its consequences, including the protection and compensation of the victims, the responsibility of the shareholders of the Instituto Goiano de Radioterapia, operator of the radioactive source, the provisional storage and the final disposal at Abadia de Goias of the radioactive waste generated by the accident are reviewed. Finally, nuclear responsibility, the inapplicability of the Law 6453/77 which deals with nuclear damages, and the state liability regime are analysed in accordance with the principles of the Brazilian Federal Constitution. (author)

  14. Impact of large beam-induced heat loads on the transient operation of the beam screens and the cryogenic plants of the Future Circular Collider (FCC)

    Science.gov (United States)

    Correia Rodrigues, H.; Tavian, L.

    2017-12-01

    The Future Circular Collider (FCC) under study at CERN will produce 50-TeV high-energy proton beams. The high-energy particle beams are bent by 16-T superconducting dipole magnets operating at 1.9 K and distributed over a circumference of 80 km. The circulating beams induce 5 MW of dynamic heat loads by several processes such as synchrotron radiation, resistive dissipation of beam image currents and electron clouds. These beam-induced heat loads will be intercepted by beam screens operating between 40 and 60 K and induce transients during beam injection. Energy ramp-up and beam dumping on the distributed beam-screen cooling loops, the sector cryogenic plants and the dedicated circulators. Based on the current baseline parameters, numerical simulations of the fluid flow in the cryogenic distribution system during a beam operation cycle were performed. The effects of the thermal inertia of the headers on the helium flow temperature at the cryogenic plant inlet as well as the temperature gradient experienced by the beam screen has been assessed. Additionally, this work enabled a thorough exergetic analysis of different cryogenic plant configurations and laid the building-block for establishing design specification of cold and warm circulators.

  15. VanderLaan Circulant Type Matrices

    Directory of Open Access Journals (Sweden)

    Hongyan Pan

    2015-01-01

    Full Text Available Circulant matrices have become a satisfactory tools in control methods for modern complex systems. In the paper, VanderLaan circulant type matrices are presented, which include VanderLaan circulant, left circulant, and g-circulant matrices. The nonsingularity of these special matrices is discussed by the surprising properties of VanderLaan numbers. The exact determinants of VanderLaan circulant type matrices are given by structuring transformation matrices, determinants of well-known tridiagonal matrices, and tridiagonal-like matrices. The explicit inverse matrices of these special matrices are obtained by structuring transformation matrices, inverses of known tridiagonal matrices, and quasi-tridiagonal matrices. Three kinds of norms and lower bound for the spread of VanderLaan circulant and left circulant matrix are given separately. And we gain the spectral norm of VanderLaan g-circulant matrix.

  16. JCO criticality accident termination operation

    International Nuclear Information System (INIS)

    Kanamori, Masashi

    2010-07-01

    In 2001, we summarized the circumstances surrounding termination of the JCO criticality accident based on testimony in the Mito District Court on December 17, 2001. JCO was the company for uranium fuels production in Japan. That document was assembled based on actual testimony in the belief that a description of the work involved in termination of the accident would be useful in some way for preventing nuclear disasters in the future. The description focuses on the witness' own behavior, and what he saw and heard, and thus is written from the perspective of action by one individual. This was done simply because it was easier for the witness to write down his memories as he remembers them. Description of the activities of other organizations and people is provided only as necessary, to ensure that consistency in the descriptive approach is not lost. The essentials of this report were rewritten as a third-person objective description in the summary of the report by the Atomic Energy Society of Japan (AESJ). Since then, comments have been received from sources such as former members of the Nuclear Safety Commission (Dr. Kenji Sumita and Dr. Akira Kanagawa), concerned parties from the former Science and Technology Agency, and reports from the JCO Criticality Accident Investigation Committee of the AESJ, and thus this report was rewritten to correct incorrect information, and add material where that was felt to be necessary. This year is the tenth year of the JCO criticality accident. To mark this occasion we have decided to translate the record of what occurred at the accident site into English so that more people can draw lessons from this accident. This report is an English version of JAEA-Technology 2009-073. (author)

  17. HEATUP: a computer program for the thermal anaysis of a LOFC accident in an HTGR

    International Nuclear Information System (INIS)

    Siman-Tov, I.I.; Turner, W.D.

    1976-11-01

    The HEATUP code, a modification of the general, time-dependent, one-, two-, and three-dimensional program HEATING5, was designed for the thermal analysis of a Loss of Forced Circulation accident in a High Temperature Gas-Cooled Reactor. This report contains a description of the computational model which includes: a description of the basic problem; a short review of preliminary results related to the choice of thermal properties, boundary conditions and initial conditions; a full description of a typical three-dimensional R-Z model and a limited one of a two-dimensional RZ model. HEATUP's additional computations are presented together with the method of input preparation. The three-dimensional model of the Fulton Generating Station Loss of Forced Circulation accident is used as a sample problem. A complete presentation of the input data is made. Also, the computer printout of the sample problem input data and results are given

  18. HEATUP: a computer program for the thermal anaysis of a LOFC accident in an HTGR

    Energy Technology Data Exchange (ETDEWEB)

    Siman-Tov, I.I.; Turner, W.D.

    1976-11-01

    The HEATUP code, a modification of the general, time-dependent, one-, two-, and three-dimensional program HEATING5, was designed for the thermal analysis of a Loss of Forced Circulation accident in a High Temperature Gas-Cooled Reactor. This report contains a description of the computational model which includes: a description of the basic problem; a short review of preliminary results related to the choice of thermal properties, boundary conditions and initial conditions; a full description of a typical three-dimensional R-Z model and a limited one of a two-dimensional RZ model. HEATUP's additional computations are presented together with the method of input preparation. The three-dimensional model of the Fulton Generating Station Loss of Forced Circulation accident is used as a sample problem. A complete presentation of the input data is made. Also, the computer printout of the sample problem input data and results are given.

  19. Severe accident source term reassessment

    International Nuclear Information System (INIS)

    Hazzan, M.J.; Gardner, R.; Warman, E.A.; Jacobs, S.B.

    1987-01-01

    This paper summarizes the status of the reassessment of severe reactor accident source terms, which are defined as the quantity, type, and timing of fission product releases from such accidents. Concentration is on the major results and conclusions of analyses with modern methods for both pressurized water reactors (PWRs) and boiling water reactors (BWRs), and the special case of containment bypass. Some distinctions are drawn between analyses for PWRs and BWRs. In general, the more the matter is examined, the consequences, or probability of serious consequences, seem to be less. (author)

  20. Civil liability concerning nuclear accidents

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    France and the USA wish to cooperate in order to promote an international regime of civil liability in order to give a fair compensation to victims of nuclear accidents as it is recommended by IAEA. On the other hand the European Commission has launched a consultation to see the necessity or not to harmonize all the civil liability regimes valid throughout Europe. According to the Commission the potential victims of nuclear accidents would not receive equal treatment at the European scale in terms of insurance cover and compensation which might distort competition in the nuclear sector. (A.C.)

  1. The nature of reactor accidents

    International Nuclear Information System (INIS)

    Domaratzki, Z.; Campbell, F.R.; Atchison, R.J.

    1981-01-01

    Reactor accidents are events which result in the release of radioactive material from a nuclear power plant due to the failure of one or more critical components of that plant. The failures, depending on their number and type, can result in releases whose consequences range from negligible to catastrophic. By way of examples, this paper describes four specific accidents which cover this range of consequence: failure of a reactor control system, loss of coolant, loss of coolant with impaired containment, and reactor core meltdown. For each a possible sequence of events and an estimate of the expected frequency are presented

  2. Second advanced ICFA beam dynamics workshop on aperture-related limitations of the performance and beam lifetime in storage rings

    International Nuclear Information System (INIS)

    Hagel, J.; Keil, E.

    1988-01-01

    These proceedings contain the papers presented at the 'Second advanced beam dynamics workshop on aperture-related limitations of the performance and beam lifetime in storage rings', which was organized in Lugano, Switzerland, from 11 to 16 April 1988, by the Beam Dynamics Panel of the International Committee for Future Accelerators (ICFA). The papers cover experiments on existing accelerators, analytical methods for determining amplitude limitations, criteria for the properties of the circulating beam and for the quality of accelerator components, and compensation schemes for field defects. (orig.)

  3. Computerized accident management support system: development for severe accident management

    International Nuclear Information System (INIS)

    Garcia, V.; Saiz, J.; Gomez, C.

    1998-01-01

    The activities involved in the international Halden Reactor Project (HRP), sponsored by the OECD, include the development of a Computerized Accident Management Support System (CAMS). The system was initially designed for its operation under normal conditions, operational transients and non severe accidents. Its purpose is to detect the plant status, analyzing the future evolution of the sequence (initially using the APROS simulation code) and the possible recovery and mitigation actions in case of an accident occurs. In order to widen the scope of CAMS to severe accident management issues, the integration of the MAAP code in the system has been proposed, as the contribution of the Spanish Electrical Sector to the project (with the coordination of DTN). To include this new capacity in CAMS is necessary to modify the system structure, including two new modules (Diagnosis and Adjustment). These modules are being developed currently for Pressurized Water Reactors and Boiling Water REactors, by the engineering of UNION FENOSA and IBERDROLA companies (respectively). This motion presents the characteristics of the new structure of the CAMS, as well as the general characteristics of the modules, developed by these companies in the framework of the Halden Reactor Project. (Author)

  4. [Diving accidents. Emergency treatment of serious diving accidents].

    Science.gov (United States)

    Schröder, S; Lier, H; Wiese, S

    2004-11-01

    Decompression injuries are potentially life-threatening incidents mainly due to a rapid decline in ambient pressure. Decompression illness (DCI) results from the presence of gas bubbles in the blood and tissue. DCI may be classified as decompression sickness (DCS) generated from the liberation of gas bubbles following an oversaturation of tissues with inert gas and arterial gas embolism (AGE) mainly due to pulmonary barotrauma. People working under hyperbaric pressure, e.g. in a caisson for general construction under water, and scuba divers are exposed to certain risks. Diving accidents can be fatal and are often characterized by organ dysfunction, especially neurological deficits. They have become comparatively rare among professional divers and workers. However, since recreational scuba diving is gaining more and more popularity there is an increasing likelihood of severe diving accidents. Thus, emergency staff working close to areas with a high scuba diving activity, e.g. lakes or rivers, may be called more frequently to a scuba diving accident. The correct and professional emergency treatment on site, especially the immediate and continuous administration of normobaric oxygen, is decisive for the outcome of the accident victim. The definitive treatment includes rapid recompression with hyperbaric oxygen. The value of adjunctive medication, however, remains controversial.

  5. On the minimum circulating power of steady state tokamaks

    International Nuclear Information System (INIS)

    Itoh, K.; Itoh, S.; Fukuyama, A.; Yagi, M.

    1995-07-01

    Circulating power for the sustenance and profile control of the steady state tokamak plasmas is discussed. The simultaneous fulfillment of the MHD stability at high beta value, the improved confinement and the stationary equilibrium requires the rotation drive as well as the current drive. In addition to the current drive efficiency, the efficiency for the rotation drive is investigated. The direct rotation drive by the external torque, such as the case of beam injection, is not efficient enough. The mechanism and the magnitude of the spontaneous plasma rotation are studied. (author)

  6. Beam divergence scaling in neutral beam injectors

    International Nuclear Information System (INIS)

    Holmes, A.J.T.

    1976-01-01

    One of the main considerations in the design of neutral beam injectors is to monimize the divergence of the primary ion beam and hence maximize the beam transport and minimize the input of thermal gas. Experimental measurements of the divergence of a cylindrical ion beam are presented and these measurements are used to analyze the major components of ion beam divergence, namely: space charge expansion, gas-ion scattering, emittance and optical aberrations. The implication of these divergence components in the design of a neutral beam injector system is discussed and a method of maximizing the beam current is described for a given area of source plasma

  7. Air ingress behavior during a primary-pipe rupture accident of HTGR

    International Nuclear Information System (INIS)

    Takeda, Tetsuaki

    1997-11-01

    The inherent properties of a HTGR facilitates the design with high degree of passive safe performances, compared to other type. However, it is still not clear if the present HTGR can maintain a passive safe function during a primary-pipe rupture accident, or what would be design criteria to guarantee the HTGR with the high degree of passive safe performances during the accident. To investigate safe characteristics, the study has been performed experimentally and analytically on the air ingress behavior during the accident. It was indicated that there are two stages in the accident of the HTGR having a reverse U-shaped channel. In the first stage, an air ingress process limits molecular diffusion and natural circulation of the gas mixture having a very slow velocity. In the second stage, the air ingress process limits the ordinary natural circulation of air throughout the reactor. A numerical calculation code has been developed to analyze thermal-hydraulic behavior during the first stage. This code provides a numerical method for analyzing a transport phenomena in a multi-component gas system by solving one-dimensional basic equations and using a flow network model. It was possible to predict or analyze the air ingress process regarding the density of the gas mixture, concentration of each gas species and duration of the first stage of the accident. It was indicated that the safe characteristics of the HTGR from the present experiment as follows. The safety cooling rate that the air ingress process terminates during the first stage exists in the HTGR having the reverse U-shaped channel. Moreover, the ordinary natural circulation of air can not produce in the second stage by injecting helium from the bottom of the pressure vessel corresponding the low-temperature side channel. Therefore, it was found that the idea of helium injection is one of useful methods for the prevention of air ingress and of graphite corrosion in the future HTGRs. (J.P.N.). 74 refs

  8. Study on natural circulation flow under reactor cavity flooding condition in advanced PWRs

    International Nuclear Information System (INIS)

    Tao Jun; Yang Jiang; Cao Jianhua; Lu Xianghui; Guo Dingqing

    2015-01-01

    Cavity flooding is an important severe accident management measure for the in-vessel retention of a degraded core by external reactor vessel cooling in advanced PWRs. A code simulation study on the natural circulation flow in the gap between the reactor vessel wall and insulation material under cavity flooding condition is performed by using a detailed mechanistic thermal-hydraulic code package RELAP 5. By simulating of an experiment carried out for studying the natural circulation flow for APR1400 shows that the code is applicable for analyzing the circulation flow under this condition. The analysis results show that heat removal capacity of the natural circulation flow in AP1000 is sufficient to prevent thermal failure of the reactor vessel under bounding heat load. Several conclusions can be drawn from the sensitivity analysis. Larger coolant inlet area induced larger natural circulation flow rate. The outlet should be large enough and should not be submerged by the cavity water to vent the steam-water mixture. In the implementation of cavity flooding, the flooding water level should be high enough to provide sufficient natural circulation driven force. (authors)

  9. Preliminary test results and CFD analysis for moderator circulation test at Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.T. [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of); Im, S.H.; Sung, H.J. [Korea Advanced Inst. of Science and Tech., Daejeon (Korea, Republic of); Seo, H.; Bang, I.C. [Ulsan National Inst. of Science and Tech., Ulsan (Korea, Republic of)

    2014-07-01

    Korea Atomic Energy Research Institute (KAERI) is carrying out a scaled-down moderator test program to simulate the CANDU6 moderator circulation phenomena during steady state operation and accident conditions. This research program includes the construction of the Moderator Circulation Test (MCT) facility, production of the validation data for self-reliant CFD tools, and development of optical measurement system using the Particle Image Velocimetry (PIV). The MCT facility includes a primary circulation loop (pipe lines, a primary side pump, a heat exchanger, valves, flow meters) and a secondary side loop (pipe lines, a secondary side pump, and an external cooling tower). The loop leakage test and non-heating test are performed in the present work. In the present work the PIV technique is used to measure the velocity distributions in the scaled moderator tank of MCT under iso-thermal test conditions. The preliminary PIV measurement data are obtained and compared with CFX code predictions. (author)

  10. RELAP5 simulation for one and two-phase natural circulation phenomenon

    International Nuclear Information System (INIS)

    Sabundjian, Gaiane; Andrade, Delvonei Alves de; Umbehaun, Pedro Ernesto; Torres, Walmir Maximo; Castro, Alfredo Jose Alvim de; Braz Filho, Francisco A.; Borges, Eduardo Madeira; Damy. Osvaldo Luiz Almeida; Torres, Eduardo

    2007-01-01

    The objective of this paper is to study the natural circulation phenomenon in one and two-phase regime. There has been a crescent interest in the scientific community in the study of the natural circulation. New generation of compact nuclear reactors uses the natural circulation for residual heat removal in case of accident or shutdown. For this study, the modeling and the simulation of the experimental circuit is performed with the RELAP5 code. The experimental circuit is mounted in the Chemical Engineering Department of the University of Sao Paulo. It is presented in this work the theoretical/experimental comparison for one and two-phase flow. These results will be stored in a database to validate RELAP5 calculations. This work was also used to training some users of RELAP5 from IEAv. (author)

  11. Preliminary test results and CFD analysis for moderator circulation test at Korea

    International Nuclear Information System (INIS)

    Kim, H.T.; Im, S.H.; Sung, H.J.; Seo, H.; Bang, I.C.

    2014-01-01

    Korea Atomic Energy Research Institute (KAERI) is carrying out a scaled-down moderator test program to simulate the CANDU6 moderator circulation phenomena during steady state operation and accident conditions. This research program includes the construction of the Moderator Circulation Test (MCT) facility, production of the validation data for self-reliant CFD tools, and development of optical measurement system using the Particle Image Velocimetry (PIV). The MCT facility includes a primary circulation loop (pipe lines, a primary side pump, a heat exchanger, valves, flow meters) and a secondary side loop (pipe lines, a secondary side pump, and an external cooling tower). The loop leakage test and non-heating test are performed in the present work. In the present work the PIV technique is used to measure the velocity distributions in the scaled moderator tank of MCT under iso-thermal test conditions. The preliminary PIV measurement data are obtained and compared with CFX code predictions. (author)

  12. Natural circulation and stratification in the various passive safety systems of the SWR 1000

    International Nuclear Information System (INIS)

    Meseth, J.

    2002-01-01

    In some of the passive safety systems of Siemens' SWR 1000 boiling water reactor (i.e. the emergency condensers and containment cooling condensers), natural circulation is the main effect on both the primary and secondary sides by which optimum system efficiency is achieved. Other passive safety systems of the SWR 1000 require natural circulation on the secondary side only (condensation of steam discharged by the safety and relief valves; cooling of the Reactor Pressure Vessel (RPV) by flooding from the outside in case of core melt), while still other systems require stratification to be effective (i.e. the passive pressure pulse transmitters and steam-driven scram tanks). Complex natural circulation and stratification can take place simultaneously if fluids with different densities are enclosed in a single volume (in a core melt accident, for example, the nitrogen, steam and hydrogen in the containment). Related problems and the solutions thereto planned for the SWR 1000 are reported from the designer's viewpoint. (author)

  13. Dynamical chaos and beam-beam models

    International Nuclear Information System (INIS)

    Izrailev, F.M.

    1990-01-01

    Some aspects of the nonlinear dynamics of beam-beam interaction for simple one-dimensional and two-dimensional models of round and flat beams are discussed. The main attention is paid to the stochasticity threshold due to the overlapping of nonlinear resonances. The peculiarities of a round beam are investigated in view of using the round beams in storage rings to get high luminosity. 16 refs.; 7 figs

  14. Beam Loss Calibration Studies for High Energy Proton Accelerators

    CERN Document Server

    Stockner, M

    2007-01-01

    CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....

  15. How to reduce the number of accidents

    CERN Multimedia

    2012-01-01

    Among the safety objectives that the Director-General has established for CERN in 2012 is a reduction in the number of workplace accidents.   The best way to prevent workplace accidents is to learn from experience. This is why any accident, fire, instance of pollution, or even a near-miss, should be reported using the EDH form that can be found here. All accident reports are followed up. The departments investigate all accidents that result in sick leave, as well as all the more common categories of accidents at CERN, essentially falls (slipping, falling on stairs, etc.), regardless of whether or not they lead to sick leave. By studying the accident causes that come to light in this way, it is possible to take preventive action to avoid such accidents in the future. If you have any questions, the HSE Unit will be happy to answer them. Contact us at safety-general@cern.ch. HSE Unit

  16. Pedestrian injury causation study (pedestrian accident typing)

    Science.gov (United States)

    1982-08-01

    A new computerized pedestrian accident typing procedure was tested on 1,997 cases from the Pedestrian Injury Causation Study (PICS). Two coding procedures were used to determine the effects of quantity and quality of information on accident typing ac...

  17. Lessons of the radiological accident in Goiania

    International Nuclear Information System (INIS)

    Alves, R.N.; Xavier, A.M.; Heilbron, P.F.L.

    1998-01-01

    On the basis of the lessons teamed from the radiological accident of Goiania, actions are described which a nuclear regulatory body should undertake while responding to an accident of this nature. (author)

  18. Socioeconomic consequences of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Tawil, J.J.; Callaway, J.W.; Coles, B.L.; Cronin, F.J.; Currie, J.W.; Imhoff, K.L.; Lewis, P.M.; Nesse, R.J.; Strenge, D.L.

    1984-06-01

    This report identifies and characterizes the off-site socioeconomic consequences that would likely result from a severe radiological accident at a nuclear power plant. The types of impacts that are addressed include economic impacts, health impacts, social/psychological impacts and institutional impacts. These impacts are identified for each of several phases of a reactor accident - from the warning phase through the post-resettlement phase. The relative importance of the impact during each accident phase and the degree to which the impact can be predicted are indicated. The report also examines the methods that are currently used for assessing nuclear reactor accidents, including development of accident scenarios and the estimating of socioeconomic accident consequences with various models. Finally, a critical evaluation is made regarding the use of impact analyses in estimating the contribution of socioeconomic consequences to nuclear accident reactor accident risk. 116 references, 7 figures, 15 tables

  19. Trucks involved in fatal accidents factbook 2008.

    Science.gov (United States)

    2011-03-01

    This document presents aggregate statistics on trucks involved in traffic accidents in 2008. The : statistics are derived from the Trucks Involved in Fatal Accidents (TIFA) file, compiled by the : University of Michigan Transportation Research Instit...

  20. Buses involved in fatal accidents factbook 2007

    Science.gov (United States)

    2010-03-01

    This document presents aggregate statistics on buses involved in traffic accidents in 2007. The : statistics are derived from the Buses Involved in Fatal Accidents (BIFA) file, compiled by the : University of Michigan Transportation Research Institut...

  1. Trucks involved in fatal accidents factbook 2007.

    Science.gov (United States)

    2010-01-01

    This document presents aggregate statistics on trucks involved in traffic accidents in 2007. The : statistics are derived from the Trucks Involved in Fatal Accidents (TIFA) file, compiled by the : University of Michigan Transportation Research Instit...

  2. Road Accident Trends in Africa and Europe

    DEFF Research Database (Denmark)

    Jørgensen, N O

    1997-01-01

    The paper decribes trends and suggests prediction models for accident risks in African and European countries......The paper decribes trends and suggests prediction models for accident risks in African and European countries...

  3. Study on the experimental VHTR safety with analysis for a hypothetical rapid depressurization accident

    International Nuclear Information System (INIS)

    Mitake, S.; Suzuki, K.; Ohno, T.; Okada, T.

    1982-01-01

    A hypothetical rapid depressurization accident of the experimental VHTR has been analyzed, including all phenomena in the accident, from its initiating depressurization of the coolant to consequential radiological hazard. Based on reliability analysis of the engineered safety features, all possible sequences, in which the safety systems are in success or in failure, have been investigated with event tree analysis. The result shows the inherent safety characteristics of the reactor and the effectiveness of the engineered safety features. And through the analysis, it has been indicated that further investigations on some phenomena in the accident, e.g., air ingress by natural circulation flow and fission product transport in the plant, will bring forth more reasonable and sufficient safety of the reactor

  4. Consequences of the Chernobyl accident

    International Nuclear Information System (INIS)

    Gerzabek, M.H.

    1990-10-01

    A collection of three papers about the fallout in Austria from the 1986 Chernobyl reactor accident is given: 1. An overview of the research projects in Austria; 2. On the transfer into and uptake by crops and animal fodder; 3. On the reduction of cesium concentration in food. 18 tabs., 21 figs., 69 refs

  5. Probabilistic studies of accident sequences

    International Nuclear Information System (INIS)

    Villemeur, A.; Berger, J.P.

    1986-01-01

    For several years, Electricite de France has carried out probabilistic assessment of accident sequences for nuclear power plants. In the framework of this program many methods were developed. As the interest in these studies was increasing and as adapted methods were developed, Electricite de France has undertaken a probabilistic safety assessment of a nuclear power plant [fr

  6. The Physics of Traffic Accidents

    Science.gov (United States)

    Knight, Peter

    1975-01-01

    Shows how physics can be used to analyze and prevent traffic accidents by determining critical speeds on curves, the behavior of motor cycles and stability of articulated vehicles, and the visibility that is needed to make a minor road junction safe. (MLH)

  7. CINETHICA - Core accident analysis code

    International Nuclear Information System (INIS)

    Nakata, H.

    1989-10-01

    A computer program for nuclear accident analysis has been developed based on the point-kinetics approximation and one-dimensional heat transfer model for reactivity feedback calculation. Hansen's method/1/ were used for the kinetics equation solution and explicit Euler method were adopted for the thermohidraulic equations. The results were favorably compared to those from the GAPOTKIN Code/2/. (author) [pt

  8. Accident consequence assessment code development

    International Nuclear Information System (INIS)

    Homma, T.; Togawa, O.

    1991-01-01

    This paper describes the new computer code system, OSCAAR developed for off-site consequence assessment of a potential nuclear accident. OSCAAR consists of several modules which have modeling capabilities in atmospheric transport, foodchain transport, dosimetry, emergency response and radiological health effects. The major modules of the consequence assessment code are described, highlighting the validation and verification of the models. (author)

  9. Reactor accidents of four decades

    International Nuclear Information System (INIS)

    Szabo, Z.

    1982-11-01

    The report covers the period between 1942 and June 30, 1982. A detailed description and a comparative analysis of reactor accidents and chemical-processing-plant excursions are presented. The analysis takes into account the following points: causes (design, maintenance, operation); events (initiating event and sequence of events); consequences (environmental impacts, personnel effects and equipment damages). (author)

  10. Crime, accidents and social control

    NARCIS (Netherlands)

    Junger, Marianne; Terlouw, Gert-Jan; van der Heijden, Peter G.M.

    1995-01-01

    This paper addresses to questions. (1) Is there a demonstrable relation between accidents and crime, does this relation hold for each type of crime and each means of transport, and does it subsist after controlling for age and gender? (2) Can social control theory explain involvements in both

  11. Accident considerations in LMFBR design

    International Nuclear Information System (INIS)

    Simpson, D.E.; Alter, H.; Fauske, H.K.; Hikido, K.; Keaten, R.W.; Stevenson, M.G.; Strawbridge, L.

    1975-12-01

    LMFBR safety design criteria are discussed from the standpoints of accident severity classification and damage criteria, and the following design events are considered: fuel failure propagation, reactivity addition faults, heat transport system events, steam generator faults, sodium spills, fuel handling and storage faults, and external events

  12. Standby after the Chernobyl accident

    International Nuclear Information System (INIS)

    1987-09-01

    The report is an investigation concerning strandby and actions by SKI (Swedish Nuclear Power Inspectorate) and SSI (National Institute of Radiation Protection) due to the Chernobyl reactor accident. It consists of a final report and two appendices. The final report is divided into two parts: 'I: Facts' and 'II: Analyzes'. 'Facts': The Swedish model for information: radio, press. Basic knowledge about ionizing radiation in the society. Resources for information. Need for information. Message forms for information. Announcements from the authorities in TV, radio, press, meeting, advertisements. Statements concerning the reactor accident and its consequences in Swedish mass media. How did the public recieve the information? 'Analyzis': Information responsibilities and policies. SSI information activities concerning radiologic accidents, conditions, methods and resources. Ditto for SKI, Swedish National Food Administration and the National Board of Agriculture. Appendix I: Information from authorities in the press three weeks after the Chernobyl accident: The material and the methods. The acute phase, the adoptation phase, the extension of the persective. What is said about the authorities in connection with Chernobyl? Appendix II: The fallout from Chernobyl, the authorities and the media coverage: The nationwide, regional and local coverage from radio and television. Ditto from the press. Topic and problem areas in reporting. Instructions from the authorities in media. Contribution in the media from people representing the authorities. Fallout in a chronologic perspective. (L.F.)

  13. New technology for accident prevention

    Energy Technology Data Exchange (ETDEWEB)

    Byne, P. [Shiftwork Solutions, Vancouver, BC (Canada)

    2006-07-01

    This power point presentation examined the effects of fatigue in the workplace and presented 3 technologies designed to prevent or monitor fatigue. The relationship between mental fatigue, circadian rhythms and cognitive performance was explored. Details of vigilance related degradations in the workplace were presented, as well as data on fatigue-related accidents and a time-line of meter-reading errors. It was noted that the direct cause of the Exxon Valdez disaster was sleep deprivation. Fatigue related accidents during the Gulf War were reviewed. The effects of fatigue on workplace performance include impaired logical reasoning and decision-making; impaired vigilance and attention; slowed mental operations; loss of situational awareness; slowed reaction time; and short cuts and lapses in optional or self-paced behaviours. New technologies to prevent fatigue-related accidents include (1) the driver fatigue monitor, an infra-red camera and computer that tracks a driver's slow eye-lid closures to prevent fatigue related accidents; (2) a fatigue avoidance scheduling tool (FAST) which collects actigraphs of sleep activity; and (3) SAFTE, a sleep, activity, fatigue and effectiveness model. refs., tabs., figs.

  14. Limits to the resolution of beam size measurement from fluorescent screens due to the thickness of the phosphor

    International Nuclear Information System (INIS)

    Johnson, C.D.

    1988-01-01

    This paper discusses the use of fluorescent screens for the measurement of beam profiles on non-circulating particle beams. An expression for the intensity of the beam profile as a function of phosphor thickness is given. 3 refs., 8 figs

  15. The radiological accident in Istanbul

    International Nuclear Information System (INIS)

    2000-01-01

    The use of radioactive materials offers a wide range of benefits throughout the world in medicine, research and industry. Precautions are, however, necessary in order to limit the exposure of persons to the radiation that is emitted. Where the amount of radioactive material is substantial, as in the case of radiotherapy sources or industrial radiography sources, extreme care is necessary to prevent accidents which may have severe consequences. Nevertheless, in spite of the precautions taken, accidents with radiation sources continue to occur, albeit infrequently. As part of its subprogramme on the safety of radiation sources, the IAEA conducts follow-up reviews of such serious accidents to give an account of their circumstances and of the medical aspects, from which organizations with responsibilities for radiation protection and the safety of sources may learn. A serious radiological accident occurred in Istanbul, Turkey, in December 1998 and January 1999 when two packages used to transport 60 Co teletherapy sources were sold as scrap metal. The persons who purchased the two packages opened them and broke open the shielded containers, thereby unknowingly exposing themselves and several others to radiation from at least one unshielded 60 Co source. The persons who dismantled the containers suffered from acute radiation syndrome. The accident came to the attention of the relevant national authority when a doctor who had examined the victims reported that he suspected the possibility of radiation exposure. The national authorities identified other individuals who might have undergone acute radiation exposures, and a total of 18 persons (including seven children) were admitted to hospital. Of these, ten adults exhibited clinical signs and symptoms of acute radiation exposure. Under the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, the Turkish authorities requested assistance from the IAEA in terms of advice on the medical

  16. Beam propagation

    International Nuclear Information System (INIS)

    Hermansson, B.R.

    1989-01-01

    The main part of this thesis consists of 15 published papers, in which the numerical Beam Propagating Method (BPM) is investigated, verified and used in a number of applications. In the introduction a derivation of the nonlinear Schroedinger equation is presented to connect the beginning of the soliton papers with Maxwell's equations including a nonlinear polarization. This thesis focuses on the wide use of the BPM for numerical simulations of propagating light and particle beams through different types of structures such as waveguides, fibers, tapers, Y-junctions, laser arrays and crystalline solids. We verify the BPM in the above listed problems against other numerical methods for example the Finite-element Method, perturbation methods and Runge-Kutta integration. Further, the BPM is shown to be a simple and effective way to numerically set up the Green's function in matrix form for periodic structures. The Green's function matrix can then be diagonalized with matrix methods yielding the eigensolutions of the structure. The BPM inherent transverse periodicity can be untied, if desired, by for example including an absorptive refractive index at the computational window edges. The interaction of two first-order soliton pulses is strongly dependent on the phase relationship between the individual solitons. When optical phase shift keying is used in coherent one-carrier wavelength communication, the fiber attenuation will suppress or delay the nonlinear instability. (orig.)

  17. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  18. Trismus: An unusual presentation following road accident

    Directory of Open Access Journals (Sweden)

    Thakur Jagdeep

    2007-01-01

    Full Text Available Trismus due to trauma usually follows road accidents leading to massive faciomaxillary injury. In the literature there is no report of a foreign body causing trismus following a road accident, this rare case is an exception. We present a case of isolated presentation of trismus following a road accident. This case report stresses on the thorough evaluation of patients presenting with trismus following a road accident.

  19. Assessment of Mobile Accident Response Capability

    International Nuclear Information System (INIS)

    1983-03-01

    This report presents the results of a DOE-sponsored assessment of nuclear accident response resources. It identifies the mobile resources that could be required to respond to different types of nuclear accidents including major ones like TMI-2, identifies the resources currently available and makes recommendations for the design and construction of additional mobile accident response resources to supplement those already in existence. This project is referred to as the Mobile Accident Response Capability (MARC) program

  20. Journalism as Cultures of Circulation

    DEFF Research Database (Denmark)

    Bødker, Henrik

    2013-01-01

    The universe of journalism has always consisted of interspersed texts, meanings and practices. Yet, much journalism research has often isolated either texts and/or contexts and as such assumed relations between professional practices, informed (rational) readers and (conceived) core texts...... of journalism. It is, however, more important than ever to shift attention away from texts to the processes through which they are circulated. This is partly because the many cultural forms of journalism (textual, institutional, technological, material, behavioural and imagined) are undergoing significant......, likes, comments, searches, journalist roles, writing and reading positions and identities etc. Such forms will be traced within the mediation of a specific event with the overall aim of beginning a theorization of the landscape of journalism as highly interrelated cultures of circulation....

  1. Radioisotopic evaluation of portal circulation

    International Nuclear Information System (INIS)

    Maliska, C.; Rosenthal, D.

    1986-01-01

    The use of a radio-tracer of portal circulation through the intestine, should prevent cruel punctures in the portal-vein or spleen as it is usually the case with traditional methods in the study of portal-system. The absorption of I-131 and Tc-99m, previously cheked in rabbits presented similar results in dogs. The time of circulation between terminal large-intestine and the liver (t-RF) was determined by external counting at hepatic level by recording radioactivity variation-time. In healthy animals the t-RF was from 20to 60 seconds, with average time of 42 seconds. In 2 animals with partial binding of portal-vein the t-RF went up to 110 and 120 seconds. (Author) [pt

  2. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  3. The radiological accident in Lilo

    International Nuclear Information System (INIS)

    2000-01-01

    The use of radioactive materials offers a wide range of benefits throughout the world in medicine, research and industry. Precautions are, however, necessary in order to limit the exposure of persons to the radiation that is emitted. Where the amount of radioactive material is substantial, such as with sources used in radiotherapy or industrial radiography, extreme care is necessary to prevent accidents that may result in severe consequences for the affected individuals. Nevertheless, in spite of the precautions taken, accidents with radiation sources continue to occur, albeit infrequently. As part of its activities dealing with the safety of radiation sources, the IAEA follows up severe accidents with a view to providing an account of their circumstances and the medical aspects from which those organizations with responsibilities for radiation protection and the safety of sources may learn. A serious radiological accident occurred in Peru in February 1999 when a welder picked up an 192 Ir industrial radiography source and put it in his pocket for several hours. This resulted in his receiving a high radiation dose that necessitated the amputation of one leg. His wife and children were also exposed, but to a much lesser extent. The Peruvian authorities requested assistance from the IAEA in obtaining advice on medical treatment. They also agreed to assist the IAEA with the subsequent review of the circumstances surrounding the accident. The IAEA is grateful to the Instituto Peruano de Energia Nuclear for its willingness to assist in the reparation of this report and, thereby, share its experience with other Member States

  4. Planning for large-scale accidents: learning from the Three Mile Island accident

    International Nuclear Information System (INIS)

    Fischer, D.W.

    1981-01-01

    Decision-making issues raised at the Three Mile Island nuclear accident in Pennsylvania are explored. The organizations involved, their interconnections, and decisions are described. The underlying issues bearing on allocation of effort to pre-accident planning and actual accident responses are also noted. Finally, a framework from this effort is used for guiding the planning of operations for future accidents. (author)

  5. Detection and analysis of accident black spots with even small accident figures.

    NARCIS (Netherlands)

    Oppe, S.

    1982-01-01

    Accident black spots are usually defined as road locations with high accident potentials. In order to detect such hazardous locations 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

  6. Use of PSA to support accident management at NPPs

    International Nuclear Information System (INIS)

    Gomez Cobo, A.

    1997-01-01

    The presentation discusses the following: Overview of PSA level 2; Introduction: Framework; Accident Progression Phenomena in the Confinement/containment; Severe Accident Sequences; Examples; Results and Insights. Accident Management: Concepts; Process; Use of PSA to support Accident; Management

  7. Accident Analysis for the NIST Research Reactor Before and After Fuel Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Baek J.; Diamond D.; Cuadra, A.; Hanson, A.L.; Cheng, L-Y.; Brown, N.R.

    2012-09-30

    Postulated accidents have been analyzed for the 20 MW D2O-moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analysis has been carried out for the present core, which contains high enriched uranium (HEU) fuel and for a proposed equilibrium core with low enriched uranium (LEU) fuel. The analyses employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron transport calculations were performed with the MCNPX code to determine homogenized fuel compositions in the lower and upper halves of each fuel element and to determine the resulting neutronic properties of the core. The accident analysis employed a model of the primary loop with the RELAP5 code. The model includes the primary pumps, shutdown pumps outlet valves, heat exchanger, fuel elements, and flow channels for both the six inner and twenty-four outer fuel elements. Evaluations were performed for the following accidents: (1) control rod withdrawal startup accident, (2) maximum reactivity insertion accident, (3) loss-of-flow accident resulting from loss of electrical power with an assumption of failure of shutdown cooling pumps, (4) loss-of-flow accident resulting from a primary pump seizure, and (5) loss-of-flow accident resulting from inadvertent throttling of a flow control valve. In addition, natural circulation cooling at low power operation was analyzed. The analysis shows that the conversion will not lead to significant changes in the safety analysis and the calculated minimum critical heat flux ratio and maximum clad temperature assure that there is adequate margin to fuel failure.

  8. Observations of Local Seychelles Circulation

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Observations of Local Seychelles Circulation Geno...goal for the proposed work is to develop predictive capabilities for physical oceanography for the Seychelles region in support of locally relevant...observations in the Seychelles region that will lead to long-term data collection efforts. In collaboration with local partnerships, we will carry out

  9. Circulating nucleic acids and evolution.

    Science.gov (United States)

    Anker, Philippe; Stroun, Maurice

    2012-06-01

    J.B. Lamarck in 1809 was the first to present a theory of evolution. He proposed it was due to the adaptation of species to environmental changes, this adaptation being acquired by the offspring. In 1868, Darwin suggested that cells excrete gemmules, which circulate through the body and reach the gonads where they are transmitted to the next generation. His main argument came from graft hybrids. In the fifties and sixties, Russian geneticists, rejecting neo-Darwinism, said that acquired characteristics were the basis of evolution. The main experiments on which they based their theory were the transmission of hereditary characteristics by a special technique of grafting between two varieties of plants. We repeated this kind of experiment and also succeeded in obtaining hereditary modifications of the pupil plants that acquired some characteristics of the mentor variety. Rather than adopting the views of the Russian scientists, we suggested that DNA was circulating between the mentor and pupil plants. Hirata's group have shown recently, by using molecular techniques such as cloning, RFLP PCR and sequencing some genes of their graft hybrids of pepper plants, that transfer of informative molecules from the mentor to the pupil plant does exist. Nucleic acids are actively released by cells; they circulate in the body. They can transform oncogenically or trigger antibody response but the only genetic transformation showing that DNA can go from the soma to the germen comes from graft hybrids. This suggests that circulating nucleic acids, in this case DNA, like Darwin's gemmules, play a role in the mechanism of evolution.

  10. Intersection layout, traffic volumes and accidents.

    NARCIS (Netherlands)

    Poppe, F.

    1988-01-01

    This paper reports on the accident research carried out as a part of a large project started in 1983. For this accident research an inventory was made of a large number of intersections.Recorded were layout features, accident data and estimates of traffic volumes. Attention will be given to the

  11. Nuclear accidents. Three mile Island (United States)

    International Nuclear Information System (INIS)

    Duco, J.

    2004-01-01

    This paper describes the accident of Three Miles Island power plant which occurred the 28 march 1979 in the United States. The accident scenario, the consequences and the reactor core and vessel, after the accident, are analyzed. (A.L.B.)

  12. Report about the radiological accident in Goiania

    International Nuclear Information System (INIS)

    Schrimer, H.P.; Gomes, C.A.; Recio, J.C.A.

    1997-01-01

    This work reports the activities developed by the technical groups who worked during the radiological accident in Goiania, held on September 1997. Several aspects of the accident are described. The final solution for the disposal of the radioactive wastes generated during the accident is presented, according to the Brazilian waste management policy. (author)

  13. School Bus Accidents and Driver Age.

    Science.gov (United States)

    McMichael, Judith

    The study examines the rates and types of school bus accidents according to the age of the school bus driver. Accident rates in North Carolina for the school year 1971-72 were analyzed using three sources of data: accident reports, driver and mileage data, and questionnaires administered to a sample of school bus drivers. Data were obtained on…

  14. 48 CFR 836.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 836.513 Accident... solicitations and contracts for construction that contain the clause at FAR 52.236-13, Accident Prevention. ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident prevention. 836...

  15. 48 CFR 36.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.513 Accident prevention. (a) The contracting officer shall insert the clause at 52.236-13, Accident Prevention, in... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Accident prevention. 36...

  16. 48 CFR 636.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 636.513 Accident prevention. (a) In... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Accident prevention. 636... contracting activities shall insert DOSAR 652.236-70, Accident Prevention, in lieu of FAR clause 52.236-13...

  17. Accidents in chemical industry: are they foreseeable?

    NARCIS (Netherlands)

    Sonnemans, P.J.M.; Körvers, P.M.W.

    2006-01-01

    Accidents recur,’ which is what Kletz [Kletz T. (1993). Lessons from disasters, how organisations have no memory and accidents recur. UK: Institution of Chemical Engineers] wrote in 1993. Indeed, despite all measures taken accidents may re-occur, but ‘disruptions’ in a process reoccur much more

  18. Epidemiology o.f· Traffic Accidents

    African Journals Online (AJOL)

    Accidents. An analysis of some 2 100 fatal traffic accidents gave the following results: males-79%; females-21%; a ratio of 4: 1. The high proportion of males to females killed in traffic accidents may be due to the fact that (a) more males commute daily in private and commercial vehicles;. (b) more females commute daily in ...

  19. Improvement of Classification of Enterprise Circulating Funds

    OpenAIRE

    Rohanova Hanna O.

    2014-01-01

    The goal of the article lies in revelation of possibilities of increase of efficiency of managing enterprise circulating funds by means of improvement of their classification features. Having analysed approaches of many economists to classification of enterprise circulating funds, systemised and supplementing them, the article offers grouping classification features of enterprise circulating funds. In the result of the study the article offers an expanded classification of circulating funds, ...

  20. Hall Effect Gyrators and Circulators

    Science.gov (United States)

    Viola, Giovanni; DiVincenzo, David P.

    2014-04-01

    The electronic circulator and its close relative the gyrator are invaluable tools for noise management and signal routing in the current generation of low-temperature microwave systems for the implementation of new quantum technologies. The current implementation of these devices using the Faraday effect is satisfactory but requires a bulky structure whose physical dimension is close to the microwave wavelength employed. The Hall effect is an alternative nonreciprocal effect that can also be used to produce desired device functionality. We review earlier efforts to use an Ohmically contacted four-terminal Hall bar, explaining why this approach leads to unacceptably high device loss. We find that capacitive coupling to such a Hall conductor has much greater promise for achieving good circulator and gyrator functionality. We formulate a classical Ohm-Hall analysis for calculating the properties of such a device, and show how this classical theory simplifies remarkably in the limiting case of the Hall angle approaching 90°. In this limit, we find that either a four-terminal or a three-terminal capacitive device can give excellent circulator behavior, with device dimensions far smaller than the ac wavelength. An experiment is proposed to achieve GHz-band gyration in millimeter (and smaller) scale structures employing either semiconductor heterostructure or graphene Hall conductors. An inductively coupled scheme for realizing a Hall gyrator is also analyzed.

  1. AECL IMPELA electron beam industrial irradiators

    International Nuclear Information System (INIS)

    Labrie, J.P.; Drewell, N.H.; Ebrahim, N.A.; Lawrence, C.B.; Mason, V.A.; Ungrin, J.; White, B.F.

    1989-01-01

    A family of industrial irradiators is being developed by AECL to cover an electron-beam energy range from 5 to 18 MeV at beam powers between 20 and 250 kW. The IMPELA family of irradiators is designed for push button, reliable operation. The major irradiator components are modular, allowing for later upgrades to meet increased demands in either electron or X-ray mode. Interface between the control system, irradiator availability and dose quality assurance is in conformance with the most demanding specifications. The IMPELA irradiators use a klystron-driven, standing-wave, L-band accelerator structure with direct injection from a rugged, triode electron gun. Direct control of the accelerating field during the beam pulse ensures constant output beam energy, independent of beam power. The first member of the family, the IMPELA 10/50 (10 MeV, 50 kW), is in the final stages of assembly at Chalk River Nuclear Laboratories. The IMPELA 10/50 is constructed around a 3.25 m long, high-power-capacity accelerator structure operated at a duty factor of 5%. Beam loading exceeds 60%. The rf power is provided by a 2 MW/150 kW modulated-anode klystron protected from load mismatches by a circulator. This prototype will be used to demonstrate the reliability and dose uniformity targets of the IMPELA family. Full beam operation of the IMPELA 10/50 is scheduled for early 1989. (orig.)

  2. Encoders for block-circulant LDPC codes

    Science.gov (United States)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2009-01-01

    Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.

  3. Deepwater Horizon Accident Investigation Report

    International Nuclear Information System (INIS)

    2010-09-01

    On the evening of April 20, 2010, a well control event allowed hydrocarbons to escape from the Macondo well onto Transocean's Deepwater Horizon, resulting in explosions and fire on the rig. Eleven people lost their lives, and 17 others were injured. The fire, which was fed by hydrocarbons from the well, continued for 36 hours until the rig sank. Hydrocarbons continued to flow from the reservoir through the wellbore and the blowout preventer (BOP) for 87 days, causing a spill of national significance. BP Exploration and Production Inc. was the lease operator of Mississippi Canyon Block 252, which contains the Macondo well. BP formed an investigation team that was charged with gathering the facts surrounding the accident, analyzing available information to identify possible causes and making recommendations to enable prevention of similar accidents in the future. The BP investigation team began its work immediately in the aftermath of the accident, working independently from other BP spill response activities and organizations. The ability to gather information was limited by a scarcity of physical evidence and restricted access to potentially relevant witnesses. The team had access to partial real-time data from the rig, documents from various aspects of the Macondo well's development and construction, witness interviews and testimony from public hearings. The team used the information that was made available by other companies, including Transocean, Halliburton and Cameron. Over the course of the investigation, the team involved over 50 internal and external specialists from a variety of fields: safety, operations, subsea, drilling, well control, cementing, well flow dynamic modeling, BOP systems and process hazard analysis. This report presents an analysis of the events leading up to the accident, eight key findings related to the causal chain of events and recommendations to enable the prevention of a similar accident. The investigation team worked separately

  4. Deepwater Horizon Accident Investigation Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    On the evening of April 20, 2010, a well control event allowed hydrocarbons to escape from the Macondo well onto Transocean's Deepwater Horizon, resulting in explosions and fire on the rig. Eleven people lost their lives, and 17 others were injured. The fire, which was fed by hydrocarbons from the well, continued for 36 hours until the rig sank. Hydrocarbons continued to flow from the reservoir through the wellbore and the blowout preventer (BOP) for 87 days, causing a spill of national significance. BP Exploration and Production Inc. was the lease operator of Mississippi Canyon Block 252, which contains the Macondo well. BP formed an investigation team that was charged with gathering the facts surrounding the accident, analyzing available information to identify possible causes and making recommendations to enable prevention of similar accidents in the future. The BP investigation team began its work immediately in the aftermath of the accident, working independently from other BP spill response activities and organizations. The ability to gather information was limited by a scarcity of physical evidence and restricted access to potentially relevant witnesses. The team had access to partial real-time data from the rig, documents from various aspects of the Macondo well's development and construction, witness interviews and testimony from public hearings. The team used the information that was made available by other companies, including Transocean, Halliburton and Cameron. Over the course of the investigation, the team involved over 50 internal and external specialists from a variety of fields: safety, operations, subsea, drilling, well control, cementing, well flow dynamic modeling, BOP systems and process hazard analysis. This report presents an analysis of the events leading up to the accident, eight key findings related to the causal chain of events and recommendations to enable the prevention of a similar accident. The investigation team worked

  5. Use of PSA and severe accident assessment results for the accident management

    International Nuclear Information System (INIS)

    Jang, S. H.; Kim, H. G.; Jang, H. S.; Moon, S. K.; Park, J. U.

    1993-12-01

    The objectives for this study are to investigate the basic principle or methodology which is applicable to accident management, by using the results of PSA and severe accident research, and also facilitate the preparation of accidents management program in the future. This study was performed as follows: derivation of measures for core damage prevention, derivation of measures for accident mitigation, application of computerized tool to assess severe accident management

  6. Use of PSA and severe accident assessment results for the accident management

    Energy Technology Data Exchange (ETDEWEB)

    Jang, S H; Kim, H G; Jang, H S; Moon, S K; Park, J U [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    1993-12-15

    The objectives for this study are to investigate the basic principle or methodology which is applicable to accident management, by using the results of PSA and severe accident research, and also facilitate the preparation of accidents management program in the future. This study was performed as follows: derivation of measures for core damage prevention, derivation of measures for accident mitigation, application of computerized tool to assess severe accident management.

  7. Simple beam profile monitor

    Energy Technology Data Exchange (ETDEWEB)

    Gelbart, W.; Johnson, R. R.; Abeysekera, B. [ASD Inc. Garden Bay, BC (Canada); Best Theratronics Ltd Ottawa Ontario (Canada); PharmaSpect Ltd., Burnaby BC (Canada)

    2012-12-19

    An inexpensive beam profile monitor is based on the well proven rotating wire method. The monitor can display beam position and shape in real time for particle beams of most energies and beam currents up to 200{mu}A. Beam shape, position cross-section and other parameters are displayed on a computer screen.

  8. Crystalline beams

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1989-01-01

    Ions in a storage ring are confined to a mean orbit by focusing elements. To a first approximation these may be described by a constant harmonic restoring force: F = -Kr. If the particles in the frame moving along with the beam have small random thermal energies, then they will occupy a cylindrical volume around the mean orbit and the focusing force will be balanced by that from the mutual repulsion of the particles. Inside the cylinder only residual two-particle interactions will play a significant role and some form of ordering might be expected to take place. The results of some of the first MD calculations showed a surprising result: not only were the particles arranged in the form of a tube, but they formed well-defined layers: concentric shells, with the particles in each shell arranged in a hexagonal lattice that is characteristic of two-dimensional Coulomb systems. This paper discusses the condense layer structure

  9. The radiological accident in Yanango

    International Nuclear Information System (INIS)

    2000-01-01

    The use of nuclear technologies has fostered new, more effective and efficient medical procedures and has substantially improved diagnostic and therapeutic capabilities. However, in order that the benefits of the use of ionizing radiation outweigh the potential hazards posed by this medium, it is important that radiation protection and safety standards be established to govern every aspect of the application of ionizing radiation. Adherence to these standards needs to be maintained through effective regulatory control, safe operational procedures and a safety culture that is shared by all. Occasionally, established safety procedures are violated and serious radiological consequences ensue. The radiological accident described in this report, which took place in Lilo, Georgia, was a result of such an infraction. Sealed radiation sources had been abandoned by a previous owner at a site without following established regulatory safety procedures, for example by transferring the sources to the new owner or treating them as spent material and conditioning them as waste. As a consequence, 11 individuals at the site were exposed for a long period of time to high doses of radiation which resulted inter alia in severe radiation induced skin injuries. Although at the time of the accident Georgia was not an IAEA Member State and was not a signatory of the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, the IAEA still provided assistance to the Government of Georgia in assessing the radiological situation, while the World Health Organization (WHO) assisted in alleviating the medical consequences of the accident. The two organizations co-operated closely from the beginning, following the request for assistance by the Georgian Government. The IAEA conducted the radiological assessment and was responsible for preparing the report. The WHO and its collaborating centres within the Radiation Emergency Medical Preparedness and Assistance Network

  10. A critical assessment of energy accident studies

    International Nuclear Information System (INIS)

    Felder, Frank A.

    2009-01-01

    A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases.

  11. Character and consequence of nuclear criticality accident

    International Nuclear Information System (INIS)

    Liu Xinhua; Liu Hua; Wu Deqiang; Li Bing

    2001-01-01

    The author describes some concepts, the process and magnitude of energy release and the destruction of the nuclear criticality accident and also describes the radiation consequence of criticality accidents from three aspects: prompt radiation, contamination in working place and release of fission products to the environment. It shows that the effects of radioactivity release from criticality accidents in the nuclear fuel processing plants on the environment and the public is minor, the main danger is from the external exposure of prompt rays. The paper make as have a correct understanding of the nuclear criticality accident and it would be helpful to take appropriate emergency response to potential criticality accident

  12. Regulatory approach to accident management in Sweden

    International Nuclear Information System (INIS)

    Hoegberg, L.

    1989-01-01

    The Swedish accident management program includes the following components: definition of overall safety and radiation protection objectives for the program; definition of appropriate accident management strategies to reach these objectives, based on plant-specific severe accident analysis; development and installation of appropriate accident management systems and associated management procedure; definition of roles and resposibilities for plant staff involved in accident management and implementation of appropriate training programs. The discussion of these components tries to highlight the basic technical concepts and approaches and the underlying safety philosophy rather than going into design details. 5 figs., 7 refs

  13. A critical assessment of energy accident studies

    Energy Technology Data Exchange (ETDEWEB)

    Felder, Frank A. [Edward J. Bloustein School of Planning and Public Policy, Rutgers, The State University of New Jersey, 33 Livingston Avenue, New Brunswick, NJ 08901 (United States)

    2009-12-15

    A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases. (author)

  14. Severe accidents: in nuclear power plants

    International Nuclear Information System (INIS)

    1986-01-01

    A ''severe'' nuclear accident refers to a reactor accident that could exceed reactor design specifications to such a degree as to prevent cooling of the reactor's core by normal means. This report summarizes the work of a NEA Senior Group of Experts who have studied the potential response of existing light-water reactors to severe accidents and have found that current designs of reactors are far more capable of coping with severe accidents than design specifications would suggest. The report emphasises the specific knowledge and means that can be used for diagnosing a severe accident and for managing its progression in order to prevent or mitigate its consequences

  15. Cost per severe accident as an index for severe accident consequence assessment and its applications

    International Nuclear Information System (INIS)

    Silva, Kampanart; Ishiwatari, Yuki; Takahara, Shogo

    2014-01-01

    The Fukushima Accident emphasizes the need to integrate the assessments of health effects, economic impacts, social impacts and environmental impacts, in order to perform a comprehensive consequence assessment of severe accidents in nuclear power plants. “Cost per severe accident” is introduced as an index for that purpose. The calculation methodology, including the consequence analysis using level 3 probabilistic risk assessment code OSCAAR and the calculation method of the cost per severe accident, is proposed. This methodology was applied to a virtual 1,100 MWe boiling water reactor. The breakdown of the cost per severe accident was provided. The radiation effect cost, the relocation cost and the decontamination cost were the three largest components. Sensitivity analyses were carried out, and parameters sensitive to cost per severe accident were specified. The cost per severe accident was compared with the amount of source terms, to demonstrate the performance of the cost per severe accident as an index to evaluate severe accident consequences. The ways to use the cost per severe accident for optimization of radiation protection countermeasures and for estimation of the effects of accident management strategies are discussed as its applications. - Highlights: • Cost per severe accident is used for severe accident consequence assessment. • Assessments of health, economic, social and environmental impacts are included. • Radiation effect, relocation and decontamination costs are important cost components. • Cost per severe accident can be used to optimize radiation protection measures. • Effects of accident management can be estimated using the cost per severe accident

  16. Beam Loss Patterns at the LHC Collimators Measurements & Simulations

    CERN Document Server

    Böhlen, Till Tobias

    2008-01-01

    The Beam Loss Monitoring (BLM) system of the Large Hadron Collider (LHC) detects particle losses of circulating beams and initiates an emergency extraction of the beam in case that the BLM thresholds are exceeded. This protection is required as energy deposition in the accelerator equipment due to secondary shower particles can reach critical levels; causing damage to the beam-line components and quenches of superconducting magnets. Robust and movable beam line elements, so-called collimators, are the aperture limitations of the LHC. Consequently, they are exposed to the excess of lost beam particles and their showers. Proton loss patterns at LHC collimators have to be determined to interpret the signal of the BLM detectors and to set adequate BLM thresholds for the protection of collimators and other equipment in case of unacceptably increased loss rates. The first part of this work investigates the agreement of BLM detector measurements with simulations for an LHC-like collimation setup. The setup consists ...

  17. Cryogenic Beam Screens for High-Energy Particle Accelerators

    CERN Document Server

    Baglin, V; Tavian, L; van Weelderen, R

    2013-01-01

    Applied superconductivity has become a key enabling technology for high-energy particle accelerators, thus making them large helium cryogenic systems operating at very low temperature. The circulation of high-intensity particle beams in these machines generates energy deposition in the first wall through different processes. For thermodynamic efficiency, it is advisable to intercept these beam-induced heat loads, which may be large in comparison with cryostat heat in-leaks, at higher temperature than that of the superconducting magnets of the accelerator, by means of beam screens located in the magnet apertures. Beam screens may also be used as part of the ultra-high vacuum system of the accelerator, by sheltering the gas molecules cryopumped on the beam pipe from impinging radiation and thus avoiding pressure runaway. Space being extremely tight in the magnet apertures, cooling of the long, slender beam screens also raises substantial problems in cryogenic heat transfer and fluid flow. We present sizing rule...

  18. Beam-Beam Interaction Studies at LHC

    CERN Document Server

    Schaumann, Michaela; Alemany Fernandez, R

    2011-01-01

    The beam-beam force is one of the most important limiting factors in the performance of a collider, mainly in the delivered luminosity. Therefore, it is essential to measure the effects in LHC. Moreover, adequate understanding of LHC beam-beam interaction is of crucial importance in the design phases of the LHC luminosity upgrade. Due to the complexity of this topic the work presented in this thesis concentrates on the beam-beam tune shift and orbit effects. The study of the Linear Coherent Beam-Beam Parameter at the LHC has been determined with head-on collisions with small number of bunches at injection energy (450 GeV). For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are as well ...

  19. SAMEX: A severe accident management support expert

    International Nuclear Information System (INIS)

    Park, Soo-Yong; Ahn, Kwang-Il

    2010-01-01

    A decision support system for use in a severe accident management following an incident at a nuclear power plant is being developed which is aided by a severe accident risk database module and a severe accident management simulation module. The severe accident management support expert (SAMEX) system can provide the various types of diagnostic and predictive assistance based on the real-time plant specific safety parameters. It consists of four major modules as sub-systems: (a) severe accident risk data base module (SARDB), (b) risk-informed severe accident risk data base management module (RI-SARD), (c) severe accident management simulation module (SAMS), and (d) on-line severe accident management guidance module (on-line SAMG). The modules are integrated into a code package that executes within a WINDOWS XP operating environment, using extensive user friendly graphics control. In Korea, the integrated approach of the decision support system is being carried out under the nuclear R and D program planned by the Korean Ministry of Education, Science and Technology (MEST). An objective of the project is to develop the support system which can show a theoretical possibility. If the system is feasible, the project team will recommend the radiation protection technical support center of a national regulatory body to implement a plant specific system, which is applicable to a real accident, for the purpose of immediate and various diagnosis based on the given plant status information and of prediction of an expected accident progression under a severe accident situation.

  20. Report on a radiotherapy underdose accident

    Energy Technology Data Exchange (ETDEWEB)

    Christodoulides, G; Christofides, S [Medical Physics Department, Nicosia General Hospital, 1450 Nicosia (Cyprus)

    1999-12-31

    Reporting information on accidents and incidents involving radiation sources provides a body of knowledge which can help to prevent accidents of a similar nature. Accident information has to be made available to users, manufacturers and regulators; An international effort to pool and analyse incident and accident information will provide more complete and reliable indicators of root causes and trends and recommendations for future accident avoidance. An accident due to human error involving a superficial x-ray therapy machine and patients treated for postoperative breast cancer is reported here. 43 women receiving radiotherapy treatment have received significantly less radiation dose than the prescribed dose. The worst dose percentage within the radiation field was 20% of the prescribed dose. The worst dose percentage on the operation scar of the breast was 52% of the prescribed radiation dose. The response to accidents/incidents in radiotherapy is discussed. (authors) 4 refs., 5 figs., 1 tabs.

  1. The epidemiology of bicyclist's collision accidents

    DEFF Research Database (Denmark)

    Larsen, L. B.

    1994-01-01

    of bicyclists and risk situations. The findings should make a basis for preventive programmes in order to decrease the number and severity of bicyclists collision accidents. Data from the emergency room in a 2 year period was combined with data from questionnaires. The study group consisted of 1021 bicyclists......The number of bicyclists injured in the road traffic in collision accidents and treated at the emergency room at Odense University Hospital has increased 66% from 1980 to 1989. The aim of this study was to examine the epidemiology of bicyclist's collision accidents and identify risk groups...... injured in collision accidents, and 1502 bicyclists injured in single accidents was used as a reference group. The young bicyclists 10-19 years of age had the highest incidence of injuries caused by collision accidents. The collision accidents had different characteristics according to counterpart. One...

  2. [Occupational noise exposure and work accidents].

    Science.gov (United States)

    Dias, Adriano; Cordeiro, Ricardo; Gonçalves, Cláudia Giglio de Oliveira

    2006-10-01

    The purpose of this study was to verify whether occupational noise exposure is a significant risk factor for work accidents in the city of Piracicaba, São Paulo State, Brazil. This hospital-based case-control study included 600 workers aged 15-60 who suffered typical occupational accidents between May and October 2004 and were seen at the Piracicaba Orthopedics and Trauma Center. The control group comprised 822 workers, aged 15-60, who were also seen at the Center, and either had a non-occupational accident or were accompanying someone who had suffered an accident. A multiple logistic regression model was adjusted with work accident as an independent variable, controlled by covariables of interest such as noise exposure. The risk of having a work accident was about twice as high among workers exposed to noise, after controlling for several covariables. Occupational noise exposure not only affected auditory health status but was also a risk factor for work accidents.

  3. Psychological factors of radiation accidents

    International Nuclear Information System (INIS)

    Lartsev, M.A.

    1995-01-01

    With reference to world, internal and personal experience, an attempt is made to reveal psychological mechanisms determining the attitude of a person to ionizing radiation using for this purpose the conceptions of mental stress and psychological adaptation. On the example of Chernobyl Nuclear Power Plant, in the light of the above conceptions, the paper describes psychic reactions of the personnel of the nuclear power plant and other groups of people to the heavy radiation accident. For improvement of the activity for liquidation of the accident after-effects it is suggested to use the system of psychophysiological support of the rescue units, including psychophysiological training and support, as well as functional rehabilitation of specialists. 11 refs

  4. 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......); 59% above 0.08%. In all cases where a pillion passenger was killed, the operator of the motorcycle had a BAC greater than 0.08%. Of the killed counterparts 2 were non-intoxicated, 2 had a BAC greater than 0.08%, and 4 were not tested. The results advocate that the law should restrict alcohol...... consumption by pillion passengers as well as by the motorcycle operator. Suggestions made to extend the data base needed for developing appropriate alcohol countermeasures by collecting sociodemographic data on drivers killed or seriously injured should be supported....

  5. The detection of criticality accidents

    International Nuclear Information System (INIS)

    Prigent, R.; Renard, C.

    It is necessary to shield the personnel from the radiological consequences of a criticality accident. In the past ten years the study programmes have highlighted fresh data which have led to new thinking on the detection philosophy and as a consequence the design of detection equipment. Concurrently, new recommendations have been drawn up by the Safety Criticality Committee. The new detection equipment was developed by the CEA on the basis of the CRAC and SILENE experiments. Its industrialization was entrusted to the Intertechnique Company and the first network installed dates back to 1976. An examination is made of the problem of accident detection, dealing in turn with detection, the characteristics of the equipment and the installation rules. To clarify the various points discussed, a parallel has been drawn between the equipment existing up to 1975 and the new generation developed since then [fr

  6. Regulatory aspects of nuclear accidents

    International Nuclear Information System (INIS)

    Caoui, A.

    1988-01-01

    The legislative systems used in different countries insist on requiring the license of the nuclear installations exploitation and on providing a nuclear safety report. For obtaining this license, the operators have to consider all situations of functioning (normal, incidental and accidental) to make workers and the public secure. The licensing procedures depend on the juridical and administrative systems of the country. Usually, protection of people against ionzing radiation is the responsibility of the ministry of health and the ministry of industry. In general, the regulations avoid to fix a definite technical standards by reason of technological development. An emergency plan is normally designed in the stage of the installation project planification. This plan contains the instructions and advices to give to populations in case of accident. The main lesson learnt from the nuclear accidents that happened is to enlarge the international cooperation in the nuclear safety field. 4 refs. (author)

  7. Recommendations about criticality accident dosimetry

    International Nuclear Information System (INIS)

    1975-07-01

    The aims of criticality accident dosimetry and the characteristics peculiar to a critical burst being defined, the requirements to be fulfilled by a dosimetric system applied to this type of measurements are presented. The devices chosen by the C.E.A. Radiation Survey Divisions, simple and cheap, are described along with the main processes to be carried out in order to evaluate doses after an accident. The apparatus necessary for detector counting and the directions for use are presented in detail, allowing standardization of measurements. A set of linear formula enables to obtain, from these measurements, all required informations about neutron fluences and spectra, along with the suitable components of the dose at the irradiated people locations [fr

  8. A beam-synchronous gated peak-detector for the LHC beam observation system

    CERN Document Server

    Levens, T E; Wehrle, U

    2013-01-01

    Measurements of the bunch peak amplitude using the longitudinal wideband wall-current monitor are a vital tool used in the Large Hadron Collider (LHC) beam observation system. These peak-detected measurements can be used to diagnose bunch shape oscillations, for example coherent quadrupole oscillations, that occur at injection and during beam manipulations. Peak-detected Schottky diagnostics can also be used to obtain the synchrotron frequency distribution and other parameters from a bunched beam under stable conditions. For the LHC a beam-synchronous gated peak detector has been developed to allow individual bunches to be monitored without the influence of other bunches circulating in the machine. The requirement for the observation of both low intensity pilot bunches and high intensity bunches for physics requires a detector front-end with a high bandwidth and a large dynamic range while the usage for Schottky measurements requires low noise electronics. This paper will present the design of this detector s...

  9. Circulating osteogentic precursor cells in non-hereditary heterotopic ossification.

    Science.gov (United States)

    Egan, Kevin P; Duque, Gustavo; Keenan, Mary Ann; Pignolo, Robert J

    2018-04-01

    Non-hereditary heterotopic ossification (NHHO) may occur after musculoskeletal trauma, central nervous system (CNS) injury, or surgery. We previously described circulating osteogenic precursor (COP) cells as a bone marrow-derived type 1 collagen + CD45 + subpopulation of mononuclear adherent cells that are able of producing extraskeletal ossification in a murine in vivo implantation assay. In the current study, we performed a tissue analysis of COP cells in NHHO secondary to defined conditions, including traumatic brain injury, spinal cord injury, cerebrovascular accident, trauma without neurologic injury, and joint arthroplasty. All bone specimens revealed the presence of COP cells at 2-14 cells per high power field. COP cells were localized to early fibroproliferative and neovascular lesions of NHHO with evidence for their circulatory status supported by their presence near blood vessels in examined lesions. This study provides the first systematic evaluation of COP cells as a contributory histopathological finding associated with multiple forms of NHHO. These data support that circulating, hematopoietic-derived cells with osteogenic potential can seed inflammatory sites, such as those subject to soft tissue injury, and due to their migratory nature, may likely be involved in seeding sites distant to CNS injury. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Beam halo in high-intensity beams

    International Nuclear Information System (INIS)

    Wangler, T.P.

    1993-01-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam

  11. Beam-beam issues in asymmetric colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  12. Transport accident emergency response plan

    International Nuclear Information System (INIS)

    Vallette-Fontaine, M.; Frantz, P.

    1998-01-01

    To comply with the IAEA recommendations for the implementation of an Emergency Response Plan as described in Safety Series 87, Transnucleaire, a company deeply involved in the road and rail transports of the fuel cycle, masters means of Emergency Response in the event of a transport accident. This paper aims at analyzing the solutions adopted for the implementation of an Emergency Response Plan and the development of a technical support and adapted means for the recovery of heavy packagings. (authors)

  13. Radiation accident in Viet Nam

    International Nuclear Information System (INIS)

    Wheatley, J.

    1998-01-01

    In November 1992 a Vietnamese research physicist was working with a microtron accelerator when he received a radiation overexposure that required the subsequent amputation of his right hand. A team from the International Atomic Energy Agency visited Hanoi in March 1993 to carry out an investigation. It was concluded that the accident occurred primarily due to a lack of safety systems although the lack of both written procedures and training in basic radiation safety were also major contributors. (author)

  14. Modelling Accident Tolerant Fuel Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Hales, Jason Dean [Idaho National Laboratory; Gamble, Kyle Allan Lawrence [Idaho National Laboratory

    2016-05-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. The United States Department of Energy (DOE) through its Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is a three-year project to perform research on two accident tolerant concepts. The final outcome of the ATF HIP will be an in-depth report to the DOE Advanced Fuels Campaign (AFC) giving a recommendation on whether either of the two concepts should be included in their lead test assembly scheduled for placement into a commercial reactor in 2022. The two ATF concepts under investigation in the HIP are uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (Idaho National Laboratory, Los Alamos National Laboratory, and Argonne National Laboratory), a comprehensive multiscale approach to modeling is being used that includes atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. Model development and fuel performance analysis are critical since a full suite of experimental studies will not be complete before AFC must prioritize concepts for focused development. In this paper, we present simulations of the two proposed accident tolerance fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. Sensitivity analyses are completed using Sandia National Laboratories’ Dakota software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). We also outline the multiscale modelling approach being employed. Considerable additional work is required prior to preparing the recommendation report for the Advanced

  15. The radiation accident at Juarez

    International Nuclear Information System (INIS)

    Koenig, L.A.

    1985-01-01

    During unconscious disassembly of a Co-60 therapy unit, 6010 metal pellets of 1 mm diameter each having 2.6 GBq (70 mCi) of activity were distributed in an uncontrolled manner. The incident was detected by mere chance. The event and the consequences are illustrated. The resulting collective dose is estimated to be 100 times bigger than that caused by the Harrisburg accident. (orig.) [de

  16. The reactor accident of Chernobyl

    International Nuclear Information System (INIS)

    Koenig, L.A.; Schuettelkopf, H.; Erat, S.; Fessler, H.; Hempelmann, S.; Maurer, K.; Pimpl, M.; Radziwill, A.

    1986-08-01

    The contamination, caused by the radioactivity released during the reactor accident of Chernobyl was measured in samples taken in the environment of the Karlsruhe Nuclear Research Center. The radioactivity was determined in air, fodder, milk, vegetables, other plants, foodstuffs, soil, precipitations, drinking water, sludge and other samples. Results of measurements are reported which were received with considerably more than 1000 samples. The evaluation of the data will be presented in KfK 4140. (orig.) [de

  17. Chernobyl accident: Assessing the data

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, B

    1986-01-01

    Data presented in the official Soviet report to the IAEA on the Chernobyl reactor accident are critically assessed. Special attention is given to the derivation of release fractions from fallout measurements, a procedure which is demonstrated to involve large elements of uncertainty. Further comments relate to estimates of plume rise and deposition velocity. A comparison is made with the predictions of previously published theoretical reactor safety studies.

  18. Medical management of radiation accidents

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-12-31

    The film gives advice on actions to be taken in case of a radiation accident. It addresses involving external irradiation of the whole and partial body, very localized exposure, uptake of radioiodine, inhalation of transuranium elements and a wound of a finger. The film is intended to illustrate the Agency`s Safety Series No. 47 entitled ``Manual on Early Medical Treatment of Possible Radiation Injury`` published in 1978

  19. Accident Locations, MDTA Accidents, Accidents on MDTA locations, Accidents on I 95, US 50, I 695, Accident on John F Kennedy Highway, Nice Bridge, Bay Bridge locations, Published in 2011, 1:1200 (1in=100ft) scale, Maryland Transportation Authority.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Accident Locations dataset current as of 2011. MDTA Accidents, Accidents on MDTA locations, Accidents on I 95, US 50, I 695, Accident on John F Kennedy Highway, Nice...

  20. Vlasov analysis of microbunching instability for magnetized beams

    Directory of Open Access Journals (Sweden)

    C.-Y. Tsai

    2017-05-01

    Full Text Available For a high-brightness electron beam with high bunch charge traversing a recirculation beam line, coherent synchrotron radiation and space charge effects may result in microbunching instability (MBI. Both tracking simulation and Vlasov analysis for an early design of a circulator cooler ring (CCR for the Jefferson Lab Electron Ion Collider (JLEIC reveal significant MBI [Ya. Derbenev and Y. Zhang, Proceedings of the Workshop on Beam Cooling and Related Topics, COOL’09, Lanzhou, China, 2009 (2009, FRM2MCCO01]. It is envisioned that the MBI could be substantially suppressed by using a magnetized beam. In this paper we have generalized the existing Vlasov analysis, originally developed for a nonmagnetized beam (or transversely uncoupled beam, to the description of transport of a magnetized beam including relevant collective effects. The new formulation is then employed to confirm prediction of microbunching suppression for a magnetized beam transport in the recirculation arc of a recent JLEIC energy recovery linac (ERL based cooler design for electron cooling. It is found that the smearing effect in the longitudinal beam phase space originates from the large transverse beam size as a nature of the magnetized beams and becomes effective through the x-z correlation when the correlated distance is larger than the microbunched scale. As a comparison, MBI analysis of the early design of JLEIC CCR is also presented in this paper.

  1. Accident analysis and DOE criteria

    International Nuclear Information System (INIS)

    Graf, J.M.; Elder, J.C.

    1982-01-01

    In analyzing the radiological consequences of major accidents at DOE facilities one finds that many facilities fall so far below the limits of DOE Order 6430 that compliance is easily demonstrated by simple analysis. For those cases where the amount of radioactive material and the dispersive energy available are enough for accident consequences to approach the limits, the models and assumptions used become critical. In some cases the models themselves are the difference between meeting the criteria or not meeting them. Further, in one case, we found that not only did the selection of models determine compliance but the selection of applicable criteria from different chapters of Order 6430 also made the difference. DOE has recognized the problem of different criteria in different chapters applying to one facility, and has proceeded to make changes for the sake of consistency. We have proposed to outline the specific steps needed in an accident analysis and suggest appropriate models, parameters, and assumptions. As a result we feed DOE siting and design criteria will be more fairly and consistently applied

  2. [Multicenter paragliding accident study 1990].

    Science.gov (United States)

    Lautenschlager, S; Karli, U; Matter, P

    1992-01-01

    During the period from 1.1.90 until 31.12.90, 86 injuries associated with paragliding were analyzed in a prospective study in 12 different Swiss hospitals with reference to causes, patterns, and frequencies. The injuries showed a mean score of over 2 and were classified as severe. Most frequent spine injuries (36%) and lesions of the lower extremity (35%) with a high risk of the ankles were diagnosed. One accident was fatal. 60% of the accidents happened during landing, 26% during launching and 14% during flight. Half of the pilots were affected during their primary training course. Most accidents were caused by inflight error of judgement--especially incorrect estimation of wind conditions--and further the choice of unfavourable landing sites. In contrast to previous injury-reports, only one equipment failure could be noted, but often the equipment was not corresponding with the experience and the weight of the pilot. To reduce the frequency of paragliding-injuries an accurate choice of equipment and an increased attention to environmental factors is mandatory. Furthermore an education-program regarding the attitude and intelligence of the pilot should be included in training courses.

  3. 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.

  4. The management of severe accidents

    International Nuclear Information System (INIS)

    Pelce, J.; Brignon, P.

    1987-01-01

    In considering severe accidents in water power reactors, a major problem that arises is how to manage them in such a way that the situation can be controlled as well as possible, from the aspects both of preventing serious damage to the core of limiting the discharge of radioactivity. A number of countries have announced provisions in the field of accident management, some already set up, others planned, but these mainly apply to preventing damage to the core. Part of this report deals with this aspect, to show that there is a fairly wide consensus on how problems should be approached. Attitudes vary, on the other hand, in the approach to mitigate radioactive release. In fact, few countries have proposed concrete steps to manage severe accidents in the final stages when the core is seriously damaged. Since it is difficult to compare different approaches, only the French approach is described. This description is however very brief, because in the five or six years since it was defined, the approach has been presented many times. The stress is placed more on the comments which this type of approach suggests, to make the subsequent general discussion easier

  5. The consequences of Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Ion Chioșilă

    2016-12-01

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

  6. Chernobyl accident. Exposures and effects

    International Nuclear Information System (INIS)

    Bennett, B.; Bouville, A.; Hall, P.; Savkin, M.; Storm, H.

    2000-01-01

    The Chernobyl accident that occurred in Ukraine in April 1986 happened during an experimental test of the electrical control system as the reactor was being shut down for routine maintenance. The operators, in violation of safety regulations, had switched off important control systems and allowed the reactor to reach unstable, low-power conditions. A sudden power surge caused a steam explosion that ruptured the reactor vessel and allowed further violent fuel-steam interactions that destroyed the reactor and the reactor building. The Chernobyl accident was the most serious to have ever occurred in the nuclear power industry. The accident caused the early death of 30 power plant employees and fire fighters and resulted in widespread radioactive contamination in areas of Belarus, the Russian Federation, and Ukraine inhabited by several million people. Radionuclides released from the reactor that caused exposure of individuals were mainly iodine-131, caesium-134 and caesium-137. Iodine-131 has a short radioactive half-life (8 days), but it can be transferred relatively rapidly through milk and leafy vegetables to humans. Iodine becomes localized in the thyroid gland. For reasons of intake of these foods, size of thyroid gland and metabolism, the thyroid doses are usually greater to infants and children than to adults. The isotopes of caesium have relatively long half-lives (caesium-134: 2 years; caesium-137: 30 years). These radionuclides cause long-term exposures through the ingestion pathway and from external exposure to these radionuclides deposited on the ground. In addition to radiation exposure, the accident caused long-term changes in the lives of people living in the contaminated regions, since measures intended to limit radiation doses included resettlements, changes in food supplies, and restrictions in activities of individuals and families. These changes were accompanied by major economic, social and political changes in the affected countries resulting

  7. Thyroid blocking after nuclear accidents

    International Nuclear Information System (INIS)

    Rendl, J.; Reiners, C.

    1999-01-01

    Following the Chernobyl accident a marked increase in thyroid cancer incidence among the children in Belarus, the Ukraine and Russia has been detected, strongly suggesting a causal relationship to the large amounts of radioactive iodine isotopes in the resulting fallout. Taking into account the Chernobyl experience the German Committee on Radiation Protection decided to reduce the intervention levels on the basis of the 1989 WHO recommendations and adopted a new concept concerning thyroid blocking in response to nuclear power plant accidents. Experimental animal studies and theoretical considerations show that thyroid blocking with potassium iodide (KI) in a dose of about 1.4 mg per kg body weight is most effective in reducing irradiation to the thyroid from the intake of radioiodine nuclides, provided KI is given within 2 hours after exposure. According to the new concept, persons over 45 years of age should not take iodine tablets because the drug could cause a greater health risk due to prevalent functional thyroid autonomy in this age group than the radioactive iodine averted by KI. On the basis of accident analysis and the new philosophy suitable distribution strategies and logistics are proposed and discussed. (orig.) [de

  8. Diarrhea caused by circulating agents.

    Science.gov (United States)

    Fabian, Elisabeth; Kump, Patrizia; Krejs, Guenter J

    2012-09-01

    Circulating agents cause intestinal secretion or changes in motility with decreased intestinal transit time, resulting in secretory-type diarrhea. Secretory diarrhea as opposed to osmotic diarrhea is characterized by large-volume, watery stools, often more than 1 L per day; by persistence of diarrhea when patients fast; and by the fact that on analysis of stool-water, measured osmolarity is identical to that calculated from the electrolytes present. Although sodium plays the main role in water and electrolyte absorption, chloride is the major ion involved in secretion. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Vasculitis of the mesenteric circulation.

    Science.gov (United States)

    Koster, Matthew J; Warrington, Kenneth J

    2017-02-01

    Vasculitis of the mesenteric circulation is an uncommon but life-threatening manifestation of systemic vasculitis. Initial symptoms are frequently non-specific and therefore patients often present to primary care physicians and gastroenterologists with abdominal pain or gastrointestinal bleeding. Given the severity of the conditions associated with mesenteric vasculitis, it is imperative to appropriately diagnose and initiate treatment of suspected cases. This review will focus on diseases commonly associated with vasculitis of the mesenteric vessels. Imaging characteristics and clinical features assisting in diagnosis as well as initial approaches to treatment are emphasized. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Autonomic Regulation of Splanchnic Circulation

    Directory of Open Access Journals (Sweden)

    Kathleen A Fraser

    1991-01-01

    Full Text Available The role of the autonomic nervous system in circulatory regulation of the splanchnic organs (stomach, small intestine, colon, liver, pancreas and spleen is reviewed. In general, the sympathetic nervous system is primarily involved in vasoconstriction, while the parasympathetic contributes to vasodilation. Vasoconstriction in the splanchnic circulation appears to be mediated by alpha-2 receptors and vasodilation by activation of primary afferent nerves with subsequent release of vasodilatory peptides, or by stimulation of beta-adrenergic receptors. As well, an important function of the autonomic nervous system is to provide a mechanism by which splanchnic vascular reserve can be mobilized during stress to maintain overall cardiovascular homeostasis.

  11. Severe accidents at nuclear power plants. Their risk assessment and accident management

    International Nuclear Information System (INIS)

    Abe, Kiyoharu.

    1995-05-01

    This document is to explain the severe accident issues. Severe Accidents are defined as accidents which are far beyond the design basis and result in severe damage of the core. Accidents at Three Mild Island in USA and at Chernobyl in former Soviet Union are examples of severe accidents. The causes and progressions of the accidents as well as the actions taken are described. Probabilistic Safety Assessment (PSA) is a method to estimate the risk of severe accidents at nuclear reactors. The methodology for PSA is briefly described and current status on its application to safety related issues is introduced. The acceptability of the risks which inherently accompany every technology is then discussed. Finally, provision of accident management in Japan is introduced, including the description of accident management measures proposed for BWRs and PWRs. (author)

  12. Criticality accident of nuclear fuel facility. Think back on JCO criticality accident

    International Nuclear Information System (INIS)

    Naito, Keiji

    2003-09-01

    This book is written in order to understand the fundamental knowledge of criticality safety or criticality accident of nuclear fuel facility by the citizens. It consists of four chapters such as critical conditions and criticality accident of nuclear facility, risk of criticality accident, prevention of criticality accident and a measure at an occurrence of criticality accident. A definition of criticality, control of critical conditions, an aspect of accident, a rate of incident, damage, three sufferers, safety control method of criticality, engineering and administrative control, safety design of criticality, investigation of failure of safety control of JCO criticality accident, safety culture are explained. JCO criticality accident was caused with intention of disregarding regulation. It is important that we recognize the correct risk of criticality accident of nuclear fuel facility and prevent disasters. On the basis of them, we should establish safety culture. (S.Y.)

  13. Evaluation of severe accident environmental conditions taking accident management strategy into account for equipment survivability assessments

    International Nuclear Information System (INIS)

    Lee, Byung Chul; Jeong, Ji Hwan; Na, Man Gyun; Kim, Soong Pyung

    2003-01-01

    This paper presents a methodology utilizing accident management strategy in order to determine accident environmental conditions in equipment survivability assessments. In case that there is well-established accident management strategy for specific nuclear power plant, an application of this tool can provide a technical rationale on equipment survivability assessment so that plant-specific and time-dependent accident environmental conditions could be practically and realistically defined in accordance with the equipment and instrumentation required for accident management strategy or action appropriately taken. For this work, three different tools are introduced; Probabilistic Safety Assessment (PSA) outcomes, major accident management strategy actions, and Accident Environmental Stages (AESs). In order to quantitatively investigate an applicability of accident management strategy to equipment survivability, the accident simulation for a most likely scenario in Korean Standard Nuclear Power Plants (KSNPs) is performed with MAAP4 code. The Accident Management Guidance (AMG) actions such as the Reactor Control System (RCS) depressurization, water injection into the RCS, the containment pressure and temperature control, and hydrogen concentration control in containment are applied. The effects of these AMG actions on the accident environmental conditions are investigated by comparing with those from previous normal accident simulation, especially focused on equipment survivability assessment. As a result, the AMG-involved case shows the higher accident consequences along the accident environmental stages

  14. Thermalydraulic processes in the reactor coolant system of a BWR under severe accident conditions

    International Nuclear Information System (INIS)

    Hodge, S.A.

    1990-01-01

    Boiling water reactors (BWRs) incorporate many unique structural features that make their expected response under severe accident conditions very different from that predicted in the case of pressurized water reactor accident sequences. Automatic main steam isolation valve (MIV) closure as the vessel water level approaches the top of the core would cause reactor vessel isolation while automatic recirculation pump trip would limit the in-vessel flows to those characteristic of natural circulation (as disturbed by vessel relief valve actuation). This paper provides a discussion of the BWR control blade, channel box, core plate, control rod guide tube, and reactor vessel safety relief valve (SRV) configuration and the effects of these structural components upon thermal hydraulic processes within the reactor vessel under severe accident conditions. The dominant BWR severe accident sequences as determined by probabilistic risk assessment are described and the expected timing of events for the unmitigated short-term station blackout severe accident sequence at the Peach Bottom atomic power station is presented

  15. Depressurization accident analyses for the Fort St. Vrain Reactor

    International Nuclear Information System (INIS)

    Paul, D.D.

    1976-01-01

    Design-basis depressurization accident analyses for the Fort St. Vrain reactor were performed using the FLODIS (Ref. 4) code. The FLODIS code models the active core, side reflector, gas annulus between the core barrel and the PCRV liner, and the PCRV cooling system. Results are presented for the Pelton circulators operating at 10,550, 8800, and 7000 rpm. Maximum temperatures of selected components are plotted as a function of time during the transient. None of the components studied exceeded the temperature at which failure or damage may occur. However, there must be sufficient mixing of the outlet gas in the lower plenum to insure the integrity of the steel liners of the steam generator inlet ducts

  16. Preliminary assessment of beam impact consequences on LHC Collimators

    CERN Document Server

    Cauchi, M; Bertarelli, A; Bruce, R; Carra, F; Dallocchio, A; Deboy, D; Mariani, N; Rossi, A; Lari, L; Mollicone, P; Sammut, N

    2011-01-01

    The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, the robustness of the collimators plays an important role. An accident, which causes the proton beam to hit a collimator, might result in severe beam-induced damage and, in some cases, replacement of the collimator, with consequent downtime for the machine. In this paper, several case studies representing different realistic beam impact scenarios are shown. A preliminary analysis of the thermal response of tertiary collimators to beam impact is presented, from which the most critical cases can be identified. Such work will also help to give an initial insight on the operational constraints of the LHC by taking into account all relevant collimator damage limits.

  17. Analytical study on thermal-hydraulic behavior of transient from forced circulation to natural circulation in JRR-3

    International Nuclear Information System (INIS)

    Hirano, Masashi; Sudo, Yukio

    1986-01-01

    Transient thermal-hydraulic behaviors of the JRR-3 which is an open-pool type research reactor has been analyzed with the THYDE-P1 code. The focal point is the thermal-hydraulic behaviors related to the core flow reversal during the transition from forced circulation downflow to natural circulation upflow. In the case of a loss-of-coolant accident (LOCA), for example, the core flow reversal is expected to occur just after the water pool isolation from the primary cooling loop with a leak. The core flow reversal should cause a sudden increase in fuel temperature and a steep decrease in the departure-from-nucleate-boiling ratio (DNBR) and the phenomenon is, therefore, very important especially for safety design and evaluation of research reactors. Major purposes of the present work are to clarify physical phenomena during the transient and to identify important parameters affecting the peak fuel temperature and the minimum DNBR. The results calculated with THYDE-P1 assuming the sequences of events of the loss-of-offsite power and LOCA help us to understand the phenomena both qualitatively and quantitatively, with respect to the safety design and evaluation. (author)

  18. Ambulance traffic accidents in Taiwan.

    Science.gov (United States)

    Chiu, Po-Wei; Lin, Chih-Hao; Wu, Chen-Long; Fang, Pin-Hui; Lu, Chien-Hsin; Hsu, Hsiang-Chin; Chi, Chih-Hsien

    2018-04-01

    Ambulance traffic accidents (ATAs) are the leading cause of occupation-related fatalities among emergency medical service (EMS) personnel. We aim to use the Taiwan national surveillance system to analyze the characteristics of ATAs and to assist EMS directors in developing policies governing ambulance operations. A retrospective, cross-sectional and largely descriptive study was conducted using Taiwan national traffic accidents surveillance data from January 1, 2011 to October 31, 2016. Among the 1,627,217 traffic accidents during the study period, 715 ATAs caused 8 deaths within 24 h and 1844 injured patients. On average, there was one ATA for every 8598 ambulance runs. Compared to overall traffic accidents, ATAs were 1.7 times more likely to result in death and 1.9 times more likely to have injured patients. Among the 715 ATAs, 8 (1.1%) ATAs were fatal and 707 (98.9%) were nonfatal. All 8 fatalities were associated with motorcycles. The urban areas were significantly higher than the rural areas in the annual number of ATAs (14.2 ± 7.3 [7.0-26.7] versus 3.1 ± 1.9 [0.5-8.4], p = 0.013), the number of ATA-associated fatalities per year (0.2 ± 0.2 [0.0-0.7] versus 0.1 ± 0.1 [0.0-0.2], p = 0.022), and the annual number of injured patients (who needed urgent hospital visits) in ATAs (19.4 ± 7.3 [10.5-30.9] versus 5.2 ± 3.8 [0.9-15.3], p traffic accident reporting system should be built to provide EMS policy guidance for ATA reduction and outcome improvements. Copyright © 2018. Published by Elsevier B.V.

  19. Control of the beam-internal target interaction at the nuclotron by means of light radiation

    Energy Technology Data Exchange (ETDEWEB)

    Artiomov, A.S. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)]. E-mail: artiomov@moonhe.jinr.ru; Anisimov, Yu.S. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Afanasiev, S.V. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Bazilev, S.N. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Zolin, L.S. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Issinsky, I.B. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Kliman, J. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Institute of Physics, Slovak Academy of Sciences, Bratislava (Slovakia); Malakhov, A.I. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Matousek, V. [Institute of Physics, Slovak Academy of Sciences, Bratislava (Slovakia); Morhac, M. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Institute of Physics, Slovak Academy of Sciences, Bratislava (Slovakia); Nikitin, V.A. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Nikiforov, A.S. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Nomokonov, P.V. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Pilyar, A.V. [Laboratory of High Energies, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Turzo, I. [Institute of Physics, Slovak Academy of Sciences, Bratislava (Slovakia)

    2005-02-11

    The light radiation from various internal targets at the nuclotron can be utilized for the operative control and time optimization of the interaction intensity of the beam. The examples presented in the paper illustrate information about the space characteristics of the circulating beam during one cycle of the accelerator run at the stages of injection, acceleration and during the physical experiments, respectively.

  20. Self-organizing maps applied to two-phase flow on natural circulation loop studies

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Leonardo F.; Cunha, Kelly de P.; Andrade, Delvonei A.; Sabundjian, Gaiane; Torres, Walmir M.; Macedo, Luiz A.; Rocha, Marcelo da S.; Masotti, Paulo H.F.; Mesquita, Roberto N. de, E-mail: rnavarro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Two-phase flow of liquid and gas is found in many closed circuits using natural circulation for cooling purposes. Natural circulation phenomenon is important on recent nuclear power plant projects for heat removal on 'loss of pump power' or 'plant shutdown' accidents. The accuracy of heat transfer estimation has been improved based on models that require precise prediction of pattern transitions of flow. Self-Organizing Maps are trained to digital images acquired on natural circulation flow instabilities. This technique will allow the selection of the more important characteristics associated with each flow pattern, enabling a better comprehension of each observed instability. This periodic flow oscillation behavior can be observed thoroughly in this facility due its glass-made tubes transparency. The Natural Circulation Facility (Circuito de Circulacao Natural - CCN) installed at Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN, is an experimental circuit designed to provide thermal hydraulic data related to one and two phase flow under natural circulation conditions. (author)