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Sample records for system leakage accident

  1. Early localization of containment leakage during an accident

    International Nuclear Information System (INIS)

    Pepin, P.; Chauliac, C.; Libmann, M.; Martinez, J.M.

    1990-01-01

    In case of an accident in a nuclear plant, checking the containment leaktightness would be a fundamental step for the diagnosis and prognosis of the radiological consequences. Significant help in this task can be provided by softwares. For that purpose, the French Atomic Energy Commission (CEA) is developing an expert system which can provide early in the accident a classification of the possible leakage paths and help understanding the necessary corrections which have to be undertaken by the utility. This software will be used at the Emergency Technical Center of the CEA. Its basic principles are described in this paper

  2. Leakage resilient password systems

    CERN Document Server

    Li, Yingjiu; Deng, Robert H

    2015-01-01

    This book investigates tradeoff between security and usability in designing leakage resilient password systems (LRP) and introduces two practical LRP systems named Cover Pad and ShadowKey. It demonstrates that existing LRP systems are subject to both brute force attacks and statistical attacks and that these attacks cannot be effectively mitigated without sacrificing the usability of LRP systems. Quantitative analysis proves that a secure LRP system in practical settings imposes a considerable amount of cognitive workload unless certain secure channels are involved. The book introduces a secur

  3. Support calculations for management of PRISE leakage accidents

    Energy Technology Data Exchange (ETDEWEB)

    Matejovic, P.; Vranka, L. [Nuclear Power Plants Research Inst. Vuje, Trnava (Slovakia)

    1997-12-31

    Accidents involving primary-to-secondary leakage (PRISE) caused by rupture of one or a few tubes are well known design basis events in both, western and VVER NPPs. Operating experience and in-service inspections of VVER-440 units have demonstrated also the potential for large PRISE leaks in the case of the steam generator (SG) primary collector cover lift-up (Rovno NPP). Without performing any countermeasure for limitation of SG collector cover lift-up, a full opening results in PRISE leak with an equivalent diameter 107 mm. Although this accident was not considered in the original design, this event is usually analysed as DBA too. Different means are available for detection and mitigation of PRISE leakage in NPPs currently in operation (J.Bohunice V-1 and V-2) or under construction (Mochovce) in Slovakia. 8 refs.

  4. Testing to determine the leakage behavior of inflatable seals subject to severe accident loadings

    International Nuclear Information System (INIS)

    Parks, M.B.

    1988-01-01

    Under the sponsorship of the United States Nuclear Regulatory Commission, Sandia National Laboratories is currently developing test validated methods to predict the pressure capacity, at elevated temperatures, of light water reactor (LWR) nuclear containment vessels subject to loads well beyond their design basis - the so-called severe accident. Scale model tests of containments with the major penetrations represented have been carried to functional failure by internal pressurization. Also, combined pressure and elevated temperature tests of typical compression seals and gaskets, a full size personnel airlock, and of typical electrical penetration assemblies (EPAs), have been conducted in order to better understand the leakage behavior of containment penetrations. Because inflatable seals are also a part of the pressure boundary of some containments, it is important to understand their leakage behavior as well. This paper discusses the results of tests that were performed to better define the leakage behavior of inflatable seals when subjected to loads well beyond their design basis

  5. Evaluation of the leakage behavior of inflatable seals subject to severe accident conditions

    International Nuclear Information System (INIS)

    Parks, M.B.

    1989-11-01

    Sandia National Laboratories, under the sponsorship of the United States Nuclear Regulatory Commission, is currently developing test validated methods to predict the pressure capacity of light water reactor containment buildings when subjected to postulated severe accident conditions. These conditions are well beyond the design basis. Scale model tests of steel and reinforced concrete containments have been conducted as well as tests of typical containment penetrations. As a part of this effort, a series of tests was recently conducted to determine the leakage behavior of inflatable seals. These seals are used to prevent leakage around personnel and escape lock doors of some containments. The results of the inflatable seals tests are the subject of this report. Inflatable seals were tested at both room temperature and at elevated temperatures representative of postulated severe accident conditions. Both aged (radiation and thermal) and unaged seals were included in the test program. The internal seal pressure at the beginning of each test was varied to cover the range of seal pressures actually used in containments. For each seal pressure level, the external (containment) pressure was increased until significant leakage past the seals was observed. Parameters that were monitored and recorded during the tests were the internal seal pressure, chamber pressure, leakage past the seals, and temperature of the test chamber and fixture to which the seals were attached. 8 refs., 34 figs., 7 tabs

  6. 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

  7. Effects of sodium fires on structures and materials. Practical experience with sodium leakage accidents

    International Nuclear Information System (INIS)

    Freudenstein, K.F.

    1989-01-01

    A few sodium leakage, incidents happened in SNR 300 nuclear power plant during pre-nuclear operation which were of minor importance with respect to sodium fires. The most important sodium fire accident in the past happened in the Almeria Solar platform in Spain during the attempt to repair a valve while leaving accidentally the circuit under 4 bar overpressure. Considerable damage to pipes, valves, its insulation and its support structures was observed in the influence zone of the fire. Post accident analysis gave a leaked mass of about 14 m 3 , at a sodium temperature of 225 deg. C, the leakage lasting approximately half an hour, and burning under convective heat exchange with the external air in a section of 40 m 2 up to a height of 6 m down to the catch pans. Some local temperatures were determined by metallurgical means, integral support temperatures estimated from mechanical deformation observed. From these temperatures it was concluded that a massive spray type fire must have happened. The results fall in the interpretation range of sodium-spray fire test results. (author)

  8. A Model for Determining Leakage in Water Distribution Systems

    OpenAIRE

    Stathis, Jonathan Alexander

    1998-01-01

    Leaks in pipe networks cause significant problems for utilities and water users in terms of lost revenue and interrupted service. In many cities the leakage is as high as forty percent. A water audit is carried out to assess system-wide leakage. However, to detect leakage at the level of a pipeline, a physical measurement technique is generally employed. For large cities the distribution piping length amounts to a few thousand miles. Therefore, the physical measurements can become tediou...

  9. Pressure control for minimizing leakage in water distribution systems

    Directory of Open Access Journals (Sweden)

    Nourhan Samir

    2017-12-01

    Full Text Available In the last decades water resources availability has been a major issue on the international agenda. In a situation of worsening scarcity of water resources and the rapidly increasing of water demands, the state of water losses management is part of man’s survival on earth. Leakage in water supply networks makes up a significant amount, sometimes more than 70% of the total water losses. The best practices suggest that pressure management is one of the most effective way to reduce the amount of leakage in a water distribution system. The approach presented in this study is aimed at modeling leakage as a function of pressure and pipe length, calibrating leakage coefficient, using fixed pressure reducing valves (PRVs to develop pressure fluctuation and developing WaterCAD scenarios to minimize leakage through the most effective settings of PRVs. This approach was applied on a district metered area (DMA in Alexandria, Egypt. The application of this approach produced some encouraging results, where the leakage through DMA was dropped by 37% for the best scenario. Thus, this approach is recommended as a decision support tool for determining a desirable solution for leakage reduction. Keywords: District measure area, Infrastructure leakage index, Leakage, Pressure management, Water supply networks

  10. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  11. Development of leakage monitoring system using radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. C.; Lee, D. S. [Seoil College, Seoul (Korea); Cho, Y. S. [Konyang University, Nonsan (Korea); Shin, S. K. [Sungkyunkwan Univ., Seoul (Korea)

    2000-04-01

    This study is to development the potable neutron back-scattering gauge for leakage and detecting liquid interface of an oil and liquid tank, using a radioisotopes. For this purpose, small sized, light weight potable gauge is to be designed as to develope neutron shielding mechanism, low power supply circuit, high voltage circuit, measurement circuit, and operating handle etc. The user will be able to set the duration of the time interval, the scale, the high voltage, the threshold, the channel window, the selection whether the data storage or not, the selection whether the scale, high voltage, threshold and window fix or not at any time. The counted pulse will be displayed with the numerical value and the line bar. The gauge will be able to connect to an IBM compatible PC via a serial port, power will be supplied by internal battery. 9 refs., 28 figs., 10 tabs. (Author)

  12. Possible pressurized thermal shock events during large primary to secondary leakage. The Hungarian AGNES project and PRISE accident scenarios in VVER-440/V213 type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Perneczky, L. [KFKI Atomic Energy Research Inst., Budabest (Hungary)

    1997-12-31

    Nuclear power plants of WWER-440/213-type have several special features. Consequently, the transient behaviour of such a reactor system should be different from the behaviour of the PWRs of western design. The opening of the steam generator (SG) collector cover, as a specific primary to secondary circuit leakage (PRISE) occurring in WWER-type reactors happened first time in Rovno NPP Unit I on January 22, 1982. Similar accident was studied in the framework of IAEA project RER/9/004 in 1987-88 using the RELAP4/mod6 code. The Hungarian AGNES (Advanced General and New Evaluation of Safety) project was performed in the period 1991-94 with the aim to reassess the safety of the Paks NPP using state-of-the-art techniques. The project comprised three type of analyses for the primary to secondary circuit leakages: Design Basis Accident (DBA) analyses, Pressurized Thermal Shock (PTS) study and deterministic analyses for Probabilistic Safety Analysis (PSA). Major part of the thermohydraulic analyses has been performed by the RELAP5/mod2.5/V251 code version with two input models. 32 refs.

  13. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Science.gov (United States)

    2010-10-01

    ... following minimum requirements: (1) A leakage survey with leak detector equipment must be conducted in business districts, including tests of the atmosphere in gas, electric, telephone, sewer, and water system... survey with leak detector equipment must be conducted outside business districts as frequently as...

  14. Development of Wireless System for Containment Integrated Leakage Rate Test

    International Nuclear Information System (INIS)

    Lee, Kwang-Dae; Oh, Eung-Se; Yang, Seung-Ok

    2006-01-01

    The containment system leakage rate should be estimated periodically with reliable test equipment. In light-water reactor nuclear power plants, ANSI/ANS- 56.8 is a basis for determining leakage rates. Two types of data acquisition system, centralized type and networked type, has been used. In centralized type, all sensors are connected directly from sensors in the containment to the measuring equipment outside the building. The other hand, the networked type has several branch chains which connect one group of the network-sensors together. To test leakage rate, more than 20 temperature sensors and 6 humidity sensors, which are different for each plant, should be installed on a specific level in the containment. A wireless technology gives the benefits such as reducing installation efforts, making pretest easy, so it is widely used more and more in the plant monitoring. As the containment system has many kinds of complex barriers to the radio frequency, the radio power and frequency band for better transmission rate as well as the interference by the radio frequency should be considered. The overview of the wireless sensor system for the containment leakage rate test is described here and the test results on Yonggwang unit 4 PWR plant is presented

  15. Benchmarking leakage from water reticulation systems in South Africa

    African Journals Online (AJOL)

    driniev

    5 (Special edition). 25. Available on website http://www.wrc.org.za. Benchmarking leakage from water reticulation systems in. South Africa. Caryn Seago1*, Jay Bhagwan2 and Ronnie McKenzie1. 1WRP Consulting ... limited and that careful management should be applied when ..... purchase price (or product price) of water.

  16. Radiation leakage dose from Elekta electron collimation system.

    Science.gov (United States)

    Pitcher, Garrett M; Hogstrom, Kenneth R; Carver, Robert L

    2016-09-08

    This study provided baseline data required for a greater project, whose objective was to design a new Elekta electron collimation system having significantly lighter electron applicators with equally low out-of field leakage dose. Specifically, off-axis dose profiles for the electron collimation system of our uniquely configured Elekta Infinity accelerator with the MLCi2 treatment head were measured and calculated for two primary purposes: 1) to evaluate and document the out-of-field leakage dose in the patient plane and 2) to validate the dose distributions calculated using a BEAMnrc Monte Carlo (MC) model for out-of-field dose profiles. Off-axis dose profiles were measured in a water phantom at 100 cm SSD for 1 and 2 cm depths along the in-plane, cross-plane, and both diagonal axes using a cylindrical ionization chamber with the 10 × 10 and 20 × 20 cm2 applicators and 7, 13, and 20 MeV beams. Dose distributions were calculated using a previously developed BEAMnrc MC model of the Elekta Infinity accelerator for the same beam energies and applicator sizes and compared with measurements. Measured results showed that the in-field beam flatness met our acceptance criteria (± 3% on major and ±4% on diagonal axes) and that out-of-field mean and maximum percent leakage doses in the patient plane met acceptance criteria as specified by the International Electrotechnical Commission (IEC). Cross-plane out-of-field dose profiles showed greater leakage dose than in-plane profiles, attributed to the curved edges of the upper X-ray jaws and multileaf collimator. Mean leakage doses increased with beam energy, being 0.93% and 0.85% of maximum central axis dose for the 10 × 10 and 20 × 20 cm2 applicators, respectively, at 20 MeV. MC calculations predicted the measured dose to within 0.1% in most profiles outside the radiation field; however, excluding model-ing of nontrimmer applicator components led to calculations exceeding measured data by as much as 0.2% for some regions

  17. Investigation of conditions inside the reactor building annulus of a PWR plant of KONVOI type in case of severe accidents with increased containment leakages

    International Nuclear Information System (INIS)

    Bakalov, Ivan; Sonnenkalb, Martin

    2018-01-01

    Improvements of the implemented severe accident management (SAM) concepts have been done in all operating German NPPs after the Fukushima Daiichi accidents following recommendations of the German Reactor Safety Commission (RSK) and as a result of the stress test being performed. The efficiency of newly developed severe accident management guidelines (SAMG) for a PWR KONVOI reference plant related to the mitigation of challenging conditions inside the reactor building (RB) annulus due to increased containment leakages during severe accidents have been assessed. Based on two representative severe accident scenarios the releases of both hydrogen and radionuclides into the RB annulus have been predicted with different boundary conditions. The accident scenarios have been analysed without and with the impact of several SAM measures (already planned or proposed in addition), which turned out to be efficient to mitigate the consequences. The work was done within the frame of a research project financially supported by the Federal Ministry BMUB.

  18. Aerospace Accident - Injury Autopsy Data System -

    Data.gov (United States)

    Department of Transportation — The Aerospace Accident Injury Autopsy Database System will provide the Civil Aerospace Medical Institute (CAMI) Aerospace Medical Research Team (AMRT) the ability to...

  19. Modern diagnostic systems for loose parts, vibration and leakage monitoring

    International Nuclear Information System (INIS)

    Kunze, U.

    1997-01-01

    The modern diagnostic systems for loose parts, vibration and leakage monitoring of Siemens marked improvements in signal detection, ease of operation, and the display of information. The paper gives an overview on: Loose parts monitoring system KUeS '95 - a computer-based system. The knowledge and experience about loose parts detection incorporated into this system can be characterized as ''intelligence''. Vibration monitoring system SUeS '95 - a fully automated system for early detection of changes in the vibration patterns of the reactor coolant system components and reactor pressure vessel internals. Leak detection system FLUeS - a system that detects even small leaks in steam-carrying components and very accurately determines their location. Leaks are detected on the moisture distribution in a sample air column into which the escaping steam locally diffuses. All systems described represent the latest state of technology. Nevertheless a considerable amount of operational experience can be reported. (author). 5 refs, 10 figs

  20. Leakage radiation spectroscopy of organic/dielectric/metal systems

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Kawalec, Tomasz; Kostiučenko, Oksana

    2014-01-01

    side of a hemisphere fused silica prism with an index matching liquid was illuminated under normal incidence by a He-Cd 325 nm laser. Two orthogonal linear polarizations were used both parallel and perpendicular to the detection plane. Spectrally resolved leakage radiation was observed on the opposite...... excitons and surface plasmon polaritons (SPPs) of the metal/dielectric boundary. The presence of the SiO2 layer considerably changes the dispersion curve in comparison to the one of the Ag/p-6P/air system. However, the Ag/SiO2/p-6P/air stack forms a stable structure allowing construction of organic...

  1. Safety analysis of accident localization system

    International Nuclear Information System (INIS)

    1999-01-01

    A complex safety analysis of accident localization system of Ignalina NPP was performed. Calculation results obtained, results of non-destruct ing testing and experimental data of reinforced concrete testing of buildings does not revealed deficiencies of buildings of accident localization system at unit 1 of Ignalina NPP. Calculations were performed using codes NEPTUNE, ALGOR, CONTAIN

  2. SETI via Leakage from Light Sails in Exoplanetary Systems

    Science.gov (United States)

    Guillochon, James; Loeb, Abraham

    2015-10-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI).

  3. SETI VIA LEAKAGE FROM LIGHT SAILS IN EXOPLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Guillochon, James; Loeb, Abraham

    2015-01-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI)

  4. Severe Accident Analysis for Containment Filtered Venting System Design

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd, Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. After TMI accident, many countries (Sweden, Germany, France) requires containment venting system like FCVS (filtered containment venting system), which can allow for the release of the over-pressure through a scrubber normally containing water and chemicals to reduce the radioactive material releases to the environment. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. This study examines the thermodynamic behavior due to different vent strategies for a large PWR during severe accidents for the OPR1000 Korea nuclear power plant. The representative accident scenario is identified and the sensitivity analysis with varying conditions (i. e. vent line size and vent initiation pressure) is conducted by using numerical simulation. The effects of venting during the severe accident with containment pressurization are examined. The accident scenarios are selected by using both of the qualitative judgement and the preliminary calculations and the sensitivity analysis on vent line size and vent initiation timing is conducted. As a result, the general trend of containment behavior due to venting can be found. Summarizing the findings, two conflict trends are found: - The maximum discharged flow rate would be higher as the vent line size and vent opening pressure increases. - The decay heat and the aerosol mass delivered to CFVS would be higher as the vent line size and vent opening pressure decreases. Regarding the flow rate, decay heat and aerosol mass are important factor for CFVS design, it would be necessary to find the optimum design specification with economical and regulatory considerations.

  5. Leakage Current Elimination of Four-Leg Inverter for Transformerless Three-Phase PV Systems

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; He, Ran; Jian, Jiamin

    2016-01-01

    Eliminating the leakage current is one of the most important issues for transformerless three phase photovoltaic (PV) systems. In this paper, the leakage current elimination of a three-phase four-leg PV inverter is investigated. With the common mode loop model established, the generation mechanism...

  6. Benchmarking leakage from water reticulation systems in South Africa

    African Journals Online (AJOL)

    A project to assess the levels of leakage in 30 water utilities throughout South Africa was initiated by the Water Research Commission. The BENCHLEAK software was used to evaluate the water utilities and performance indicators calculated by the model were used to compare levels of non-revenue water. Results showed ...

  7. Value-impact analysis of regulatory options for resolution of Generic Issue C-8: MSIV [Main Steam Isolation Valve] leakage and LCS [Leakage Control System] failure

    International Nuclear Information System (INIS)

    Jamison, J.D.; Vo, T.V.; Tabatabai, A.S.

    1990-05-01

    This report describes the analysis conducted to establish the basis for answering two remaining regulatory questions facing the NRC staff regarding the resolution of Generic Issue C-8, specifically:(1) What action should the NRC take concerning plants that currently have a leakage control system (LCS)? and, (2) What action should the NRC take concerning plants that do not have an LCS? Using individual MSIV leak test data, the performance of a system of eight such valves in a standard BWR con-figuration was modeled. The performance model was used along with estimates of core damage accident frequency and calculated dose consequences to determine the public risk associated with each of the alternatives. The occupational exposure implications of each alternative were calculated using estimates of labor hours in radiation zones that would be incurred or avoided. The costs to industry of implementing each alternative were estimated using standard cost formulae and NRC staff estimates. The cost to the NRC were estimated based on the effort incurred or avoided for reviews or other staff actions engendered by the selection of or avoided for reviews or other staff actions engendered by the selection of a particular alternative. The cost and risks thus calculated suggest that no regulatory action can be justified on the basis of risk reduction or cost savings. 12 refs., 1 tab

  8. Americal National Standard critical accident alarm system

    International Nuclear Information System (INIS)

    Smith, D.R.

    1975-01-01

    An American National Standard has been developed to provide guidance for the design, maintenance, and use of criticality accident alarm systems. Discussion includes several details of this Standard, N16.2-1969, and of a revised version which is now nearing certification

  9. A new on-line leakage current monitoring system of ZnO surge arresters

    International Nuclear Information System (INIS)

    Lee, Bok-Hee; Kang, Sung-Man

    2005-01-01

    This paper presents a new on-line leakage current monitoring system of zinc oxide (ZnO) surge arresters. To effectively diagnose the deterioration of ZnO surge arresters, a new algorithm and on-line leakage current detection device, which uses the time-delay addition method, for discriminating the resistive and capacitive currents was developed to use in the aging test and durability evaluation for ZnO arrester blocks. A computer-based measurement system of the resistive leakage current, the on-line monitoring device can detect accurately the leakage currents flowing through ZnO surge arresters for power frequency ac applied voltages. The proposed on-line leakage current monitoring device of ZnO surge arresters is more highly sensitive and gives more linear response than the existing devices using the detection method of the third harmonic leakage currents. Therefore, the proposed leakage current monitoring device can be useful for predicting the defects and performance deterioration of ZnO surge arresters in power system applications

  10. Development of Traffic Accidents Control System

    Directory of Open Access Journals (Sweden)

    Andrey Borisovich Nikolaev

    2015-05-01

    Full Text Available Proposed a structure of traffic accidents control system included three main parts: pre-processing, decision support and monitoring. For decision support systems we propose a method that allows to make decisions on the basis of fuzzy situational management. The advantage of the method: it allows to formalize a set of typical traffic situations, using the theory of fuzzy sets and to carry out selection of the desired management action.

  11. Limitations of systemic accident analysis methods

    Directory of Open Access Journals (Sweden)

    Casandra Venera BALAN

    2016-12-01

    Full Text Available In terms of system theory, the description of complex accidents is not limited to the analysis of the sequence of events / individual conditions, but highlights nonlinear functional characteristics and frames human or technical performance in relation to normal functioning of the system, in safety conditions. Thus, the research of the system entities as a whole is no longer an abstraction of a concrete situation, but an exceeding of the theoretical limits set by analysis based on linear methods. Despite the issues outlined above, the hypothesis that there isn’t a complete method for accident analysis is supported by the nonlinearity of the considered function or restrictions, imposing a broad vision of the elements introduced in the analysis, so it can identify elements corresponding to nominal parameters or trigger factors.

  12. SU-F-J-144: Scatter and Leakage Survey of An Integrated MR-Linac System

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Bosco, G; Darenbourg, B; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To assess the scatter and leakage radiation of an integrated 1.5T MRI-Linac system. Methods: A 150cc chamber (model 96020C, Inovision) was used in all the scatter and leakage measurements, after being recalibrated for MV energy by the Accredited Dosimetry Calibration Laboratory at MD Anderson. The scatter radiation was measured by placing a 25 cm stack of solid-water materials at iso-center on the patient couch to simulate patient scatter. Gantry angles were positioned at 0 degree (beam pointing downward) and 270 (beam pointing laterally). Scatter radiation was measured at selective locations inside the RF room. Beam stopper leakage was measured at the exterior panel of the gantry. The head leakage was measured at 1 meter away from the Linac head in the direction which was determined to be the area of maximum leakage by wrapped films test. All measurements were repeated with the 1.5T magnetic field turned off to study the effect of magnetic field. Results: When the magnet was on (B=1.5T), the maximum head leakage at 1 meter was 191.6mR/1000MU. The scatter radiation at 1 meter from the iso-center was 1.091R/1000MU when the radiation beam was pointing downward, 1.296R/1000MU when the beam pointed laterally. The beam stopper leakage was measured as 299.4 mR/1000MU at the exterior panel of the gantry. When magnet was off (B=0), the head leakage was measured as 198.6mR/1000MU. The scatter radiation at 1 meter was 1.153R/1000MU when beam pointed downward, 1.287R/1000MU when beam pointed laterally. The beam stopper leakage was measured as 309.4 mR/1000MU at the exterior panel of the gantry. Conclusion: The measurements indicate that the scatter and leakage radiation from the integrated MR-Linac system are in-line with the expected values. The beam stopper leakage is approximately 300 mR/1000MU. The leakage and scatter difference with the magnetic field ON and OFF was within 5%. The authors received a corporate sponsored grant from Elekta which is the vendor of

  13. Small gas leakage rate measuring and monitoring system for spent fuel transport/storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Ryoji [Hitachi Zosen Corp., Tokyo (Japan); Aritomi, Masanori; Matsuzaki, Mitsuo; Kawa, Tsunemichi

    1997-12-01

    A containment function of transport and/or storage casks of radioactive materials is essential to prevent the materials from being released excessively into the environment. It is not practical for containment tests to measure directly the radioactivity release so that gas volumetric leakage rates are usually assessed and gas pressure decrease or increase method is usually applied. As gas flow model for evaluation, the ISO standards has deleted the concept of choked flow which is adopted by ANSI N14.5. Provided that the choked flow is not adopted to the leakage rate evaluation, the criteria of the test should be severe, and a new leakage rate measuring system with high accuracy and reasonable measuring time is required. Transport casks are often inspected in a temporary cask-storage facility where simultaneous measurement of many casks is required. In a storage cask system, multiple casks are monitored on their containment function during a storage period, and the method for simultaneous monitoring at many points for long term is required. In this study, two kinds of small gas leakage rate measuring systems are developed. One is to measure gas leakage rates directly and is called `flow measuring system`, which can measure gas leakage rate of 10{sup -4} to 10{sup -2} cm{sup 3}/s with high accuracy and short measuring time. The other is to measure the pressure decreasing rate and is called `pressure decreasing rate measuring system`, which can monitor the pressure change at many points simultaneously. (author)

  14. Development of a totally integrated severe accident training system

    International Nuclear Information System (INIS)

    Kim, Ko Ryu; Park, Sun Hee; Choi, Young; Kim, Dong Ha

    2006-01-01

    Recently KAERI has developed the severe accident management guidance to establish the Korea standard severe accident management system. On the other hand the PC-based severe accident training simulator SATS has been developed, which uses the MELCOR code as the simulation engine. The simulator SATS graphically displays and simulates the severe accidents with interactive user commands. Especially the control capability of SATS could make a severe accident training course more interesting and effective. In this paper we will describe the development and functions of the electrical guidance module, HyperKAMG, and the SATS-HyperKAMG linkage system designed for a totally integrated and automated severe accident training. (author)

  15. Design and Development of Gas Leakage Monitoring System Using Arduino and ZigBee

    OpenAIRE

    Yan, Huan Hui; Rahayu, Yusnita

    2014-01-01

    Gas leakage in industrial area causes many health issues. Thus, to prevent such disasters happen, the atmosphere of a workplace should be regularly monitored and controlled, in order to maintain the clean air environment. However, efforts in industrial air quality control have been impeded by the lack of science-based approaches to identify and assess atmosphere air quality and level of dangerous gas. Therefore, a monitoring system for gas leakage detection needs to be developed. For the deve...

  16. Ship cabin leakage alarm based on ARM SCM

    Science.gov (United States)

    Qu, Liyan

    2018-03-01

    If there is a leakage in the cabin of a sailing ship, it is a major accident that threatens the personnel and property of the ship. If we can’t take timely measures, there will be a devastating disaster. In order to judge the leakage of the cabin, it is necessary to set up a leakage alarm system, so as to achieve the purpose of detecting and alarming the leakage of the cabin, and avoid the occurrence of accidents. This paper discusses the design of ship cabin leakage alarm system based on ARM SCM. In order to ensure the stability and precision of the product, the hardware design of the alarm system is carried out, such as circuit design, software design, the programming of SCM, the software programming of upper computer, etc. It is hoped that it can be of reference value to interested readers.

  17. Leakage detection system for radioactive waste storage tanks

    International Nuclear Information System (INIS)

    Woods, W.W.; Eul, W.A.

    1979-01-01

    The patent describes a combination of elements for detecting leakage of electrically conductive fluids from tanks, including a reference electrode, an AC generator connected between the tank and the reference electrode, and one or more sensing electrodes positioned between the tank and the reference electrode. The storage tank and reference electrode are in contact with the ground. When the AC generator is energized, current flows in the circuit, and creates an electric field in the ground between the tank and the reference electrode. The sensing electrodes are positioned so that they are within the electric field when the AC generator is energized. An electric potential measuring device, such as a voltmeter, is used to measure the electric potential at the sensing electrodes relative to the tank. A significant change in the electric potential at any one or more of the sensing electrodes is an indication that a leak has occurred in the tank

  18. Passive Decay Heat Removal Strategy of Integrated Passive Safety System (IPSS) for SBO-combined Accidents

    International Nuclear Information System (INIS)

    Kim, Sang Ho; Chang, Soon Heung; Jeong, Yong Hoon

    2014-01-01

    The weak points of nuclear safety would be in outmoded nuclear power plants like the Fukushima reactors. One of the systems for the safety enhancement is integrated passive safety system (IPSS) proposed after the Fukushima accidents. It has the five functions for the prevention and mitigation of a severe accident. Passive decay heat removal (PDHR) strategy using IPSS is proposed for coping with SBO-combined accidents in this paper. The two systems for removing decay heat before core-melt were applied in the strategy. The accidents were simulated by MARS code. The reference reactor was OPR1000, specifically Ulchin-3 and 4. The accidents included loss-of-coolant accidents (LOCA) because the coolant losses could be occurred in the SBO condition. The examples were the stuck open of PSV, the abnormal open of SDV and the leakage of RCP seal water. Also, as LOCAs with the failure of active safety injection systems were considered, various LOCAs were simulated in SBO. Based on the thermal hydraulic analysis, the probabilistic safety analysis was carried out for the PDHR strategy to estimate the safety enhancement in terms of the variation of core damage frequency. AIMS-PSA developed by KAERI was used for calculating CDF of the plant. The IPSS was applied in the PDHR strategy which was developed in order to cope with the SBO-combined accidents. The estimation for initiating SGGI or PSIS was based on the pressure in RCS. The simulations for accidents showed that the decay heat could be removed for the safety duration time in SBO. The increase of safety duration time from the strategy provides the increase of time for the restoration of AC power

  19. Preliminary evaluation of the Accident Response Mobile Manipulation System for accident site salvage operations

    International Nuclear Information System (INIS)

    Trujillo, J.M.; Morse, W.D.; Jones, D.P.

    1994-01-01

    This paper describes and evaluates operational experiences with the Accident Response Mobile Manipulation System (ARMMS) during simulated accident site salvage operations which might involve nuclear weapons. The ARMMS is based upon a teleoperated mobility platform with two Schilling Titan 7F Manipulators

  20. Leakage Performance of the GM + CCL Liner System for the MSW Landfill

    Directory of Open Access Journals (Sweden)

    Fan Jingjing

    2014-01-01

    Full Text Available The contaminants in the landfill leachate press pose a grave threat to environment of the soil and the groundwater beneath the landfill. Despite there being strict requirements in relevant provisions of both domestic and foreign countries for the design of the bottom liner system. Pollution of the soil and the groundwater still took place in a number of landfills because of the leakage. To investigate the leakage rate of the liner systems, the minimum design requirements of the liner systems are summarized according to the provisions of four countries, including China, USA, Germany, and Japan. Comparative analyses using one-dimensional transport model are conducted to study the leakage performance of these liner systems composed of geomembrance (GM and compacted clay layer (CCL meeting the relevant minimum design requirements. Then parametric analyses are conducted to study the effects of the hydraulic head, the thickness of GM, the hydraulic conductivity of CCL, and so forth on the leakage performance of the liner system. It is concluded that the liner system designed according to the minimum design requirements of Germany provide the best antileakage performance, while that of Japan performs the lowest. The key parameters affecting the failure time of the liner system are summarized. Finally, some suggestions for the design of the liner systems are made according to the analyses.

  1. The effect of system modeling on the Fukushima accident evolution

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L.E.; Fontanet, J.; López, C.; Fernández, E.

    2015-07-01

    The Fukushima accident is becoming both a unique opportunity and a huge challenge for severe accident analysis. The OECD-BSAF project has articulated a good part of the modeling efforts conducted so far. Inside this project, CIEMAT has conducted forensic analyses of the Fukushima accident in units 1 through 3 with MELCOR 2.1 and it has postulated a set of accident scenarios consistent with data. Beyond specific results, sensitivity analyses on safety systems performance and prevailing boundary conditions have highlighted the need of conducting uncertainty analyses when modeling NPPs severe accident scenarios. (Author)

  2. Estimation of leakage frequencies from different systems at Nordic nuclear power plants

    International Nuclear Information System (INIS)

    Poern, K.

    1999-08-01

    Within the project External Events (1994-97) it was decided to initialise the work on a handbook-, called X-Book, in order to provide the PSA analyst guidance in the selection of models and frequencies of 'external events'. Thus, the aim of the X-Book is to be complementary to the I-Book, a handbook on Initiating Events at Nordic nuclear power plants. The X-Book will, among other things, encompass the frequencies of so called system external events, i.e. initiating events that are caused by events occurring outside the system boundaries. In Version 1 of the X-Book the attention is mainly focussed on the estimation of initiating fire frequencies, per plant and per building. This frequency estimation was mainly based on data, specifically collected about fires occurred at Nordic power plants. Within the project mentioned above efforts were also started with the aim to estimate the frequencies of water/steam leakage, frequencies that can be used in PSA of risks related to flooding and steam rupture. The models and frequencies of events resulting in loss of cooling water (LOCA) that were used already in WASH-1400 have 'survived' in many later studies. According to the aim and ambitions of modern PSAs the need for improved treatment of water/steam leakages is more and more emphasised, both with respect to the modelling of the course of events and the estimation of frequencies of such events. Leakage from water-bearing systems may occur more or less spontaneously through cracks, pipe ruptures, damaged packing-boxes of pumps and valves etc. Thus this type of leakage may derive from pipe failures or leaking active or passive components. External leakage may also occur if a valve is spuriously opened between low and high pressure systems or towards a temporarily opened part of a system (Interfacing V-LOCA). This report describes the methods used in the selection of leakage data from the Nordic NPP component data base TUD as well as the models and methods applied in the

  3. Strategy generator in computerized accident management support system

    International Nuclear Information System (INIS)

    Sirola, M.

    1994-02-01

    An increased interest for research in the field of accident management of nuclear power plants can be noted. Several international programmes have been started in order to be able to understand the basic physical and chemical phenomena in accident conditions. A feasibility study has shown that it would be possible to design and develop a computerized support system for plant staff in accident situations. To achieve this goal the Halden Project has initiated a research programme on Computerized Accident Management Support (CAMS project). The aim is to utilize the capabilities of computerized tools to support the plant staff during the various accident stages. The system will include identification of the accident state, assessment of the future development of the accident and planning of accident mitigation strategies. A prototype is developed to support operators and the Technical Support Centre in decision making during serious accidents in nuclear power plants. A rule based system has been built to take care of the strategy generation. This system assists plant personnel in planning control proposals and mitigation strategies from normal operation to severe accident conditions. The idea of a safety objective tree and knowledge from the emergency procedures have been used. Future prediction requires good state identification of the plant status and some knowledge about the history of some critical variables. The information needs to be validated as well. Accurate calculations in simulators and a large database including all important information from the plant will help the strategy planning. (orig.). (40 refs., 20 figs.)

  4. RETRAN code analysis of Tsuruga-2 plant chemical volume control system (CVCS) reactor coolant leakage incident

    International Nuclear Information System (INIS)

    Kawai, H.

    2001-01-01

    JAPC purchased RETRAN, a program for transient thermal hydraulic analysis of complex fluid flow system, from the U.S. Electric Power Research Institute in 1992. Since then, JAPC has been utilizing RETRAN to evaluate safety margins of actual plant operation, in coping with troubles (investigating trouble causes and establishing countermeasures), and supporting reactor operation (reviewing operational procedures etc.). In this paper, a result of plant analysis performed on a CVCS reactor primary coolant leakage incident which occurred at JAPC's Tsuruga-2 plant (4-loop PWR, 3423 MWt, 1160 MW) on July 12 of 1999 and, based on the result, we made a plan to modify our operational procedure for reactor primary coolant leakage events in order to make earlier plant shutdown and this reduced primary coolant leakage. (author)

  5. The system development of consequence analysis for army nuclear accident

    International Nuclear Information System (INIS)

    Yuan Wei; Zuo Li; Chen Xianbo; Qu Yantao; Yang Hongwei

    2014-01-01

    Through the analysis of the assessment technique and the function characteristics of related system, domestic nuclear facilities accident consequence, assessment technique for army nuclear accident consequence was studied and the difference between the two evaluation methods were also compared. On this basis, the function, the application and the optimization of a software system that was developed for army was discussed. All of these will provide suggestion for the nuclear weapon accident consequence assessment. (authors)

  6. Single phase cascaded H5 inverter with leakage current elimination for transformerless photovoltaic system

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Jia, X.; Lu, Z.

    2016-01-01

    Leakage current reduction is one of the important issues for the transformelress PV systems. In this paper, the transformerless single-phase cascaded H-bridge PV inverter is investigated. The common mode model for the cascaded H4 inverter is analyzed. And the reason why the conventional cascade H...

  7. ATR confinement leakage determination

    International Nuclear Information System (INIS)

    Kuan, P.; Buescher, B.J.

    1998-01-01

    The air leakage rate from the Advanced Test Reactor (ATR) confinement is an important parameter in estimating hypothesized accidental releases of radiation to the environment. The leakage rate must be determined periodically to assure that the confinement has not degraded with time and such determination is one of the technical safety requirements of ATR operation. This paper reviews the methods of confinement leakage determination and presents an analysis of leakage determination under windy conditions, which can complicate the interpretation of the determined leakage rates. The paper also presents results of analyses of building air exchange under windy conditions. High wind can enhance air exchange and this could increase the release rates of radioisotopes following an accident

  8. Improving Reliability of Information Leakage Detection and Prevention Systems

    Directory of Open Access Journals (Sweden)

    A. V. Mamaev

    2011-03-01

    Full Text Available The problem of protection from deliberate leaks of information is one of the most difficult. Integrated systems of information protection against insider have a serious drawback. Using this disadvantage the offender receives the possibility of unauthorized theft of information from working machine.

  9. Specific interaction of central nervous system myelin basic protein with lipids effects of basic protein on glucose leakage from liposomes

    NARCIS (Netherlands)

    Gould, R.M.; London, Y.

    1972-01-01

    The leakage from liposomes preloaded with glucose was continuously monitored in a Perkin-Elmer Model 356 dual beam spectrophotometer using an enzyme-linked assay system. The central nervous system myelin basic protein (A1 protein) caused a 3–4-fold increase in the rate of leakage from liposomes

  10. Development of a Computer Based Problem-Oriented Automated Remote Leakage Detection Control System

    Directory of Open Access Journals (Sweden)

    Kosach Alisa

    2017-01-01

    Full Text Available We explore the architecture and the concept of building an automation remote leakage detection system, in particular ’ a system for collection and processing of information. As practice shows, the development of those systems is a lengthy and time-consuming process involving management of heterogeneous hardware and analysis of large amounts of data. To implement the task, it is proposed to use the SCADA industry standard, universal communication protocols, and for data processing – open source database management systems and cluster analysis algorithms. A universal approach makes it possible to develop a scalable problem-oriented system. This approach takes into account the information received and processed during the leakage detection process.

  11. Detection device for off-gas system accidents

    International Nuclear Information System (INIS)

    Kubota, Ryuji; Tsuruoka, Ryozo; Yamanari, Shozo.

    1984-01-01

    Purpose: To rapidly isolate the off-gas system by detecting the off-gas system failure accident in a short time. Constitution: Radiation monitors are disposed to ducts connecting an exhaust gas area and an air conditioning system as a portion of a turbine building. The ducts are disposed independently such that they ventilate only the atmosphere in the exhaust gas area and do not mix the atmosphere in the turbine building. Since radioactivity issued upon off-gas accidents to the exhaust gas area is sucked to the duct, it can be detected by radiation detection monitors in a short time after the accident. Further, since the operator judges it as the off-gas system accident, the off-gas system can be isolated in a short time after the accident. (Moriyama, K.)

  12. Power crowbar system coupled by a current transformer with very low leakage inductance

    International Nuclear Information System (INIS)

    Kitagawa, S.; Hirano, K.I.

    1976-01-01

    A reliable, efficient power crowbar system has been developed for fast pinch experiments. In order to reduce the effective impedance of series capacitor system, a current transformer with extremely low leakage inductance has been designed and used. Primary and secondary windings of the transformer are alternately arranged as closely as possible. As a result, the leakage inductance is reduced to 2 nH. It is demonstrated that a current of 390 kA, the rise time of which is 4.5 μsec, is sustained for 100 μsec. Much larger system is being built, which maintains a current of 1 MA over 1 msec. The life of crowbar gap switches is prolonged by the aid of a mechanically-driven metal-to-metal contact switch. Another crowbar switch system with a high coulomb rating is under consideration, in which a gap switch is used together with a saturable reactor and a current transformer

  13. Development of an accident management expert system for containment assessment

    International Nuclear Information System (INIS)

    Nelson, W.R.; Sebo, D.E.; Haney, L.N.

    1987-01-01

    The United States Nuclear Regulatory Commission (USNRSC) is sponsoring a program at the Idaho National Engineering Laboratory (INEL) to develop an accident management expert system. The intended users of the system are the personnel of the NRC Operations Center in Washington, D.C. The expert system will be used to help NRC personnel monitor and evaluate the status and management of the containment during a severe reactor accident. The knowledge base will include severe accident knowledge regarding the maintenance of the critical safety functions, especially containment integrity, during an accident. This paper summarizes the concepts that have been developed for the accident management expert system, and the plans that have been developed for its implementation

  14. A catchment-scale groundwater model including sewer pipe leakage in an urban system

    Science.gov (United States)

    Peche, Aaron; Fuchs, Lothar; Spönemann, Peter; Graf, Thomas; Neuweiler, Insa

    2016-04-01

    Keywords: pipe leakage, urban hydrogeology, catchment scale, OpenGeoSys, HYSTEM-EXTRAN Wastewater leakage from subsurface sewer pipe defects leads to contamination of the surrounding soil and groundwater (Ellis, 2002; Wolf et al., 2004). Leakage rates at pipe defects have to be known in order to quantify contaminant input. Due to inaccessibility of subsurface pipe defects, direct (in-situ) measurements of leakage rates are tedious and associated with a high degree of uncertainty (Wolf, 2006). Proposed catchment-scale models simplify leakage rates by neglecting unsaturated zone flow or by reducing spatial dimensions (Karpf & Krebs, 2013, Boukhemacha et al., 2015). In the present study, we present a physically based 3-dimensional numerical model incorporating flow in the pipe network, in the saturated zone and in the unsaturated zone to quantify leakage rates on the catchment scale. The model consists of the pipe network flow model HYSTEM-EXTAN (itwh, 2002), which is coupled to the subsurface flow model OpenGeoSys (Kolditz et al., 2012). We also present the newly developed coupling scheme between the two flow models. Leakage functions specific to a pipe defect are derived from simulations of pipe leakage using spatially refined grids around pipe defects. In order to minimize computational effort, these leakage functions are built into the presented numerical model using unrefined grids around pipe defects. The resulting coupled model is capable of efficiently simulating spatially distributed pipe leakage coupled with subsurficial water flow in a 3-dimensional environment. References: Boukhemacha, M. A., Gogu, C. R., Serpescu, I., Gaitanaru, D., & Bica, I. (2015). A hydrogeological conceptual approach to study urban groundwater flow in Bucharest city, Romania. Hydrogeology Journal, 23(3), 437-450. doi:10.1007/s10040-014-1220-3. Ellis, J. B., & Revitt, D. M. (2002). Sewer losses and interactions with groundwater quality. Water Science and Technology, 45(3), 195

  15. Design of a DCS Based Model for Continuous Leakage Monitoring System of Rotary Air Preheater of a Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    Madan BHOWMICK

    2011-01-01

    Full Text Available The leakage in rotary air preheater makes a considerable contribution to the reduced overall efficiency of fossil-fuel-fired thermal power plants and increase the effect on environment. Since it is normal phenomenon, continuous monitoring of leakage is generally omitted in most power plants. But for accurate analysis of the operation of the thermal power plant, this leakage monitoring plays a vital role. In the present paper, design of a DCS based model for continuous leakages monitoring of rotary air preheater has been described. In the proposed model, the existing DCS based instrumentation system has been modified and online leakage monitoring system has been developed. This model has been installed in a captive power plant with high capacity boilers and very much satisfactory operation of this system has been observed. The observed online data along with their analysis results are presented in this paper.

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

    Directory of Open Access Journals (Sweden)

    Veronika Vlčková

    2015-07-01

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

  17. Development of radiotracer technology and nucleonic control systems - Development of leakage monitoring system using radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Choon; Lee, Doon Sung [Seoil College, Seoul (Korea); Cho, Yong Suk [Konyang University, Nonsan (Korea); Shin, Seung Kwon [Sungkyunkwan University, Seoul (Korea)

    1999-04-01

    This is the equipment to find out the leakage of an oil pipeline and a water pipe reclaimed from the underground, using a Radioisotopes. For this purpose, small sized, light weight and water proofed Detection Pig in high voltage is to be designed and produced as to develope a radiation detector, high voltage power supply circuit, measurement circuit, data storage circuit, and a remote on/off function, etc. In this study, high-voltage producing circuit, an amplifier, count rate circuit, processing circuit, and radiosignal treatment part will be used as a basic material to develope a radiotracer, a radiation measuring and using equipment. And it will promote the localization of the radiation applied measuring system. As the results, domestic equipment industry will be improved a great deal. 22 refs., 22 figs., 8 tabs. (Author)

  18. Design of modified annulus air sampling system for the detection of leakage in waste transfer line

    International Nuclear Information System (INIS)

    Deokar, U.V; Khot, A.R.; Mathew, P.; Ganesh, G.; Tripathi, R.M.; Srivastava, Srishti

    2018-01-01

    Various liquid waste streams are generated during the operation of reprocessing plant. The High Level (HL), Intermediate Level (IL) and Low Level (LL) liquid wastes generated, are transferred from reprocessing plant to Waste Management Facility. These respective waste streams are transferred through pipe-in-pipe lines along the shielded concrete trench. For detection of radioactive leakage from primary waste transfer line into secondary line, sampling of the annulus air between the two pipes is carried out. The currently installed pressurized annulus air sampling system did not have online leakage detection provision. Hence, there are chances of personal exposure and airborne activity in the working area. To overcome these design flaws, free air flow modified online annulus air sampling system with more safety features is designed

  19. Modeling PWR systems for monitoring primary-to-secondary leakage using tritium tracer

    International Nuclear Information System (INIS)

    Peiffer, D.G.

    1992-01-01

    This paper discusses several techniques available for monitoring primary to secondary leakage, focusing on the advantages and disadvantages of each. A mathematical model of Millstone 2 describes the behavior of tritium activity in the secondary plant water when a leak exists. Real data from Millstone 2 illustrate the accuracy and reliability of the model and use of the model to measure the mass of water in the secondary system

  20. ADAM: An Accident Diagnostic,Analysis and Management System - Applications to Severe Accident Simulation and Management

    International Nuclear Information System (INIS)

    Zavisca, M.J.; Khatib-Rahbar, M.; Esmaili, H.; Schulz, R.

    2002-01-01

    The Accident Diagnostic, Analysis and Management (ADAM) computer code has been developed as a tool for on-line applications to accident diagnostics, simulation, management and training. ADAM's severe accident simulation capabilities incorporate a balance of mechanistic, phenomenologically based models with simple parametric approaches for elements including (but not limited to) thermal hydraulics; heat transfer; fuel heatup, meltdown, and relocation; fission product release and transport; combustible gas generation and combustion; and core-concrete interaction. The overall model is defined by a relatively coarse spatial nodalization of the reactor coolant and containment systems and is advanced explicitly in time. The result is to enable much faster than real time (i.e., 100 to 1000 times faster than real time on a personal computer) applications to on-line investigations and/or accident management training. Other features of the simulation module include provision for activation of water injection, including the Engineered Safety Features, as well as other mechanisms for the assessment of accident management and recovery strategies and the evaluation of PSA success criteria. The accident diagnostics module of ADAM uses on-line access to selected plant parameters (as measured by plant sensors) to compute the thermodynamic state of the plant, and to predict various margins to safety (e.g., times to pressure vessel saturation and steam generator dryout). Rule-based logic is employed to classify the measured data as belonging to one of a number of likely scenarios based on symptoms, and a number of 'alarms' are generated to signal the state of the reactor and containment. This paper will address the features and limitations of ADAM with particular focus on accident simulation and management. (authors)

  1. The computer aided education and training system for accident management

    International Nuclear Information System (INIS)

    Yoneyama, Mitsuru; Kubota, Ryuji; Fujiwara, Tadashi; Sakuma, Hitoshi

    1999-01-01

    The education and training system for Accident Management was developed by the Japanese BWR group and Hitachi Ltd. The education and training system is composed of two systems. One is computer aided instruction (CAI) education system and the education and training system with computer simulations. Both systems are designed to be executed on personal computers. The outlines of the CAI education system and the education and training system with simulator are reported below. These systems provides plant operators and technical support center staff with the effective education and training for accident management. (author)

  2. Severe Accident Management System On-line Network SAMSON

    International Nuclear Information System (INIS)

    Silverman, Eugene B.

    2004-01-01

    SAMSON is a computational tool used by accident managers in the Technical Support Centers (TSC) and Emergency Operations Facilities (EOF) in the event of a nuclear power plant accident. SAMSON examines over 150 status points monitored by nuclear power plant process computers during a severe accident and makes predictions about when core damage, support plate failure, and reactor vessel failure will occur. These predictions are based on the current state of the plant assuming that all safety equipment not already operating will fail. SAMSON uses expert systems, as well as neural networks trained with the back propagation learning algorithms to make predictions. Training on data from an accident analysis code (MAAP - Modular Accident Analysis Program) allows SAMSON to associate different states in the plant with different times to critical failures. The accidents currently recognized by SAMSON include steam generator tube ruptures (SGTRs), with breaks ranging from one tube to eight tubes, and loss of coolant accidents (LOCAs), with breaks ranging from 0.0014 square feet (1.30 cm 2 ) in size to breaks 3.0 square feet in size (2800 cm 2 ). (author)

  3. Single Phase Transformer-less Buck-Boost Inverter with Zero Leakage Current for PV Systems

    DEFF Research Database (Denmark)

    Mostaan, Ali; Abdelhakim, Ahmed; N. Soltani, Mohsen

    2017-01-01

    In this paper, a novel single-stage single-phase transformer-less buck-boost inverter is proposed, in which a reduced number of passive components is used. The proposed inverter combines the conventional buck, boost, and buck-boost converters in one converter in order to obtain a sinusoidal output...... voltage. In the proposed inverter, the input DC source and the load or grid have the same ground. Therefore, the leakage current problem in photovoltaic (PV) systems is eliminated. Furthermore, the proposed inverter supports the bi-directional power flow capability and it can inject reactive power...

  4. Cognitive systems engineering analysis of the JCO criticality accident

    International Nuclear Information System (INIS)

    Tanabe, Fumiya; Yamaguchi, Yukichi

    2000-01-01

    The JCO Criticality Accident is analyzed with a framework based on cognitive systems engineering. With the framework, analysis is conducted integrally both from the system viewpoint and actors viewpoint. The occupational chemical risk was important as safety constraint for the actors as well as the nuclear risk, which is due to criticality accident, to the public and to actors. The inappropriate actor's mental model of the work system played a critical role and several factors (e.g. poor training and education, lack of information on criticality safety control in the procedures and instructions, and lack of warning signs at workplace) contributed to form and shape the mental model. Based on the analysis, several countermeasures, such as warning signs, information system for supporting actors and improved training and education, are derived to prevent such an accident. (author)

  5. Analysis of Boiler Operational Variables Prior to Tube Leakage Fault by Artificial Intelligent System

    Directory of Open Access Journals (Sweden)

    Al-Kayiem Hussain H.

    2014-07-01

    Full Text Available Steam boilers are considered as a core of any steam power plant. Boilers are subjected to various types of trips leading to shut down of the entire plant. The tube leakage is the worse among the common boiler faults, where the shutdown period lasts for around four to five days. This paper describes the rules of the Artificial Intelligent Systems to diagnosis the boiler variables prior to tube leakage occurrence. An Intelligent system based on Artificial Neural Network was designed and coded in MATLAB environment. The ANN was trained and validated using real site data acquired from coal fired power plant in Malaysia. Ninety three boiler operational variables were identified for the present investigation based on the plant operator experience. Various neural networks topology combinations were investigated. The results showed that the NN with two hidden layers performed better than one hidden layer using Levenberg-Maquardt training algorithm. Moreover, it was noticed that hyperbolic tangent function for input and output nodes performed better than other activation function types.

  6. Methods for air cleaning system design and accident analysis

    International Nuclear Information System (INIS)

    Gregory, W.S.; Nichols, B.D.

    1987-01-01

    This paper describes methods, in the form of a handbook and five computer codes, that can be used for nuclear facility air cleaning system design and accident analysis. Four of the codes were developed primarily at the Los Alamos National Laboratory, and one was developed in France. Tools such as these are used to design ventilation systems in the mining industry but do not seem to be commonly used in the nuclear industry. For example, the Nuclear Air Cleaning Handbook is an excellent design reference, but it fails to include information on computer codes that can be used to aid in the design process. These computer codes allow the analyst to use the handbook information to form all the elements of a complete system design. Because these analysis methods are in the form of computer codes they allow the analyst to investigate many alternative designs. In addition, the effects of many accident scenarios on the operation of the air cleaning system can be evaluated. These tools originally were intended for accident analysis, but they have been used mostly as design tools by several architect-engineering firms. The Cray, VAX, and personal computer versions of the codes, an accident analysis handbook, and the codes availability will be discussed. The application of these codes to several design operations of nuclear facilities will be illustrated, and their use to analyze the effect of several accident scenarios also will be described

  7. A CMOS detector leakage current self-adaptable continuous reset system: Theoretical analysis

    CERN Document Server

    De Geronimo, G

    1999-01-01

    A continuous reset system for the discharge of the feedback capacitance of integrated charge preamplifiers is presented. The system, based on the use of a FET operating in the saturation region, is self-adaptable with respect to a wide range of detector leakage currents. A circuit which provides compensation of the signal from the charge amplifier is also proposed. The noise analysis, which takes into account both the stationary and non-stationary noise contributions and the effect of the rate, shows that the system, when carefully designed, can offer good signal/noise performance for applications in gamma-ray and high-energy X-ray spectroscopy. Practical layout considerations are also made.

  8. Feasibility, safety and cement leakage in vertebroplasty of osteoporotic and malignant compression fractures using ultra-viscous cement and hydraulic delivery system.

    Science.gov (United States)

    Georgy, Bassem A

    2012-01-01

    The major complications arising from vertebroplasty or kyphoplasty are related to leakage of cement beyond the confines of the collapsed vertebral body. Traditionally, a liquid (low viscosity) cement is used in most vertebroplasty systems available on the market, coupled with mechanical injection devices or one mL syringes. The purpose of this study is to evaluate the feasibility and safety, as well as study cement leakage patterns, in vertebroplasty performed for both osteoporotic and malignant vertebral compression fractures using ultraviscous cement injected by the hydraulic CONFIDENCE Vertebral Augmentation System. Retrospective evaluation of postoperative images. Single center inpatient and outpatient population. A retrospective evaluation of clinical charts and postoperative X-ray imaging was performed in 122 cases; a total of 214 levels were treated. The study group comprised a total of 163 levels of benign osteoporotic fractures and 51 levels of various malignant lesions. The degree of leakage, seen in postoperative films, was assessed at each treated level using a strict 4-point scale (none, mild, moderate, severe). For benign lesions, there was no leakage in 82 levels (50%), mild venous leakage in 38 levels (23%), moderate venous leakage in 4 levels (2%), mild disc leakage in 28 levels (17%), moderate disc leakage in 7 levels (4%), mild paravertebral leakage in 2 levels (1%), and moderate paravertebral leakage in 2 levels (1%). No severe leakage or epidural leakage were seen. For malignant lesions, there was no leakage in 25 levels (49%), mild venous leakage in 12 levels (24%), moderate venous leakage in 4 levels (8%), mild disc leakage in 7 levels (14%), moderate disc leakage in one level (2%), mild paravertebral leakage in one level (2%), and one level showed a mild epidural leakage (2%). Retrospective study, single center. Percutaneous cement augmentation in osteoporotic and malignant compression fractures using a highly viscous cement that can be

  9. A systems approach to the management of radiation accidents

    International Nuclear Information System (INIS)

    Richter, L.L.; Berk, H.W.; Teates, C.D.; Larkham, N.E.; Friesen, E.J.; Edlich, R.F.

    1980-01-01

    Management of radiation accident patients should have a multidisciplinary approach that includes all health professionals as well as members of public safety agencies. Emergency plans for radiation accidents include detection of the ionizing radiation, patient evacuation, resuscitation, and decontamination. The resuscitated patient should be transported to a radiation control area located outside but adjacent to the emergency department. Ideally this area is accessed through an entrance separate from that used for the main flow of daily emergency department patients. The hospital staff, provided with protective clothing, dosimeters, and preprinted guidelines, continues the resuscitation and definitive care of the patient. This system approach to the management of radiation accidents may be tailored to meet the specific needs of other emergency medical systems

  10. Proton-sensing transistor systems for detecting ion leakage from plasma membranes under chemical stimuli.

    Science.gov (United States)

    Imaizumi, Yuki; Goda, Tatsuro; Schaffhauser, Daniel F; Okada, Jun-Ichi; Matsumoto, Akira; Miyahara, Yuji

    2017-03-01

    The membrane integrity of live cells is routinely evaluated for cytotoxicity induced by chemical or physical stimuli. Recent progress in bioengineering means that high-quality toxicity validation is required. Here, we report a pH-sensitive transistor system developed for the continuous monitoring of ion leakage from cell membranes upon challenge by toxic compounds. Temporal changes in pH were generated with high reproducibility via periodic flushing of HepG2 cells on a gate insulator of a proton-sensitive field-effect transistor with isotonic buffer solutions with/without NH 4 Cl. The pH transients at the point of NH 4 Cl addition/withdrawal originated from the free permeation of NH 3 across the semi-permeable plasma membranes, and the proton sponge effect produced by the ammonia equilibrium. Irreversible attenuation of the pH transient was observed when the cells were subjected to a membrane-toxic reagent. Experiments and simulations proved that the decrease in the pH transient was proportional to the area of the ion-permeable pores on the damaged plasma membranes. The pH signal was correlated with the degree of hemolysis produced by the model reagents. The pH assay was sensitive to the formation of molecularly sized pores that were otherwise not measurable via detection of the leakage of hemoglobin, because the hydrodynamic radius of hemoglobin was greater than 3.1nm in the hemolysis assay. The pH transient was not disturbed by inherent ion-transporter activity. The ISFET assay was applied to a wide variety of cell types. The system presented here is fast, sensitive, practical and scalable, and will be useful for validating cytotoxins and nanomaterials. The plasma membrane toxicity and hemolysis are widely and routinely evaluated in biomaterials science and biomedical engineering. Despite the recent development of a variety of methods/materials for efficient gene/drug delivery systems to the cytosol, the methodologies for safety validation remain unchanged in

  11. MELCOR Accident Consequence Code System (MACCS)

    International Nuclear Information System (INIS)

    Chanin, D.I.; Sprung, J.L.; Ritchie, L.T.; Jow, Hong-Nian

    1990-02-01

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

  12. MELCOR Accident Consequence Code System (MACCS)

    International Nuclear Information System (INIS)

    Jow, H.N.; Sprung, J.L.; Ritchie, L.T.; Rollstin, J.A.; Chanin, D.I.

    1990-02-01

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

  13. MELCOR Accident Consequence Code System (MACCS)

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-02-01

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

  14. MELCOR Accident Consequence Code System (MACCS)

    International Nuclear Information System (INIS)

    Rollstin, J.A.; Chanin, D.I.; Jow, H.N.

    1990-02-01

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

  15. EAC european accident code. A modular system of computer programs to simulate LMFBR hypothetical accidents

    International Nuclear Information System (INIS)

    Wider, H.; Cametti, J.; Clusaz, A.; Devos, J.; VanGoethem, G.; Nguyen, H.; Sola, A.

    1985-01-01

    One aspect of fast reactor safety analysis consists of calculating the strongly coupled system of physical phenomena which contribute to the reactivity balance in hypothetical whole-core accidents: these phenomena are neutronics, fuel behaviour and heat transfer together with coolant thermohydraulics in single- and two-phase flow. Temperature variations in fuel, coolant and neighbouring structures induce, in fact, thermal reactivity feedbacks which are added up and put in the neutronics calculation to predict the neutron flux and the subsequent heat generation in the reactor. At this point a whole-core analysis code is necessary to examine for any hypothetical transient whether the various feedbacks result effectively in a negative balance, which is the basis condition to ensure stability and safety. The European Accident Code (EAC), developed at the Joint Research Centre of the CEC at Ispra (Italy), fulfills this objective. It is a modular informatics structure (quasi 2-D multichannel approach) aimed at collecting stand-alone computer codes of neutronics, fuel pin mechanics and hydrodynamics, developed both in national laboratories and in the JRC itself. EAC makes these modules interact with each other and produces results for these hypothetical accidents in terms of core damage and total energy release. 10 refs

  16. [A monitoring system for work-related accidents in Piracicaba, São Paulo, Brazil].

    Science.gov (United States)

    Cordeiro, Ricardo; Vilela, Rodolfo Andrade Gouveia; de Medeiros, Maria Angélica Tavares; Gonçalves, Cláudia Giglio de Oliveira; Bragantini, Clarice Aparecida; Varolla, Antenor J; Celso, Stephan

    2005-01-01

    The authors report on the development of a work accident monitoring system in Piracicaba, São Paulo State, Brazil, with the following characteristics: information feeding the system is obtained in real time directly from accident treatment centers; the system has universal monitoring, covering all work-related accidents in Piracicaba, regardless of the nature of the worker's employment conditions, place of work, or place of residence; health surveillance and promotion of health initiatives are triggered by identification of sentinel events; spatial distribution analysis of work-related accidents is a basic tool in designing accident awareness strategies and accident prevention policies. The system was implemented in November 2003 and by October 2004 had identified 5,320 work-related accidents, or a 3.8% annual proportional incidence of work-related accidents in the municipal area. We illustrate spatial analysis of registered work-related accidents and present a detailed investigation of one example of a serious accident.

  17. 78 FR 6732 - Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report...

    Science.gov (United States)

    2013-01-31

    ... SECURITY Coast Guard 33 CFR Parts 173, 174, 181, and 187 RIN 1625-AB45 Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report Database AGENCY: Coast Guard, DHS. ACTION: Rule... Numbering System, Vessel Identification System, and Boating Accident Report Database rule became effective...

  18. Central nervous system affecting drugs and road traffic accidents ...

    African Journals Online (AJOL)

    These accidents (RTA) have been attributed to various causes including driving under the influence of drugs that affect the central nervous system (CNS). Objective: This study was aimed at determining the role of CNS affecting drugs in the causation of RTA among these motorcyclists and also to make recommendations ...

  19. Leakage based precoding for multi-user MIMO-OFDM systems

    KAUST Repository

    Sadek, Mirette

    2011-08-01

    In downlink multi-user multiple-input multiple-output (MIMO) transmissions, several precoding schemes have been proposed to decrease interference among users. Notable among these precoding schemes is one that uses the signal-to-leakage-plus-noise ratio (SLNR) as an optimization criterion. In this paper, leveraging the efficiency of the SLNR optimization, we generalize this precoding scheme to MIMO orthogonal frequency division multiplexing (OFDM) multi-user systems where the OFDM is used to overcome the inter-symbol- interference (ISI) introduced by multipath channels. We also introduce a channel compensation technique that reconstructs the channel at the transmitter for every time instant given a significantly lower channel feedback rate by the receiver. © 2006 IEEE.

  20. The Nevada railroad system: Physical, operational, and accident characteristics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-09-01

    This report provides a description of the operational and physical characteristics of the Nevada railroad system. To understand the dynamics of the rail system, one must consider the system`s physical characteristics, routing, uses, interactions with other systems, and unique operational characteristics, if any. This report is presented in two parts. The first part is a narrative description of all mainlines and major branchlines of the Nevada railroad system. Each Nevada rail route is described, including the route`s physical characteristics, traffic type and volume, track conditions, and history. The second part of this study provides a more detailed analysis of Nevada railroad accident characteristics than was presented in the Preliminary Nevada Transportation Accident Characterization Study (DOE, 1990).

  1. 75 FR 49869 - Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report...

    Science.gov (United States)

    2010-08-16

    ... SECURITY Coast Guard 33 CFR Parts 173, 174, 181, and 187 RIN 1625-AB45 Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report Database AGENCY: Coast Guard, DHS. ACTION..., Vessel Identification System, and Boating Accident Report Database. DATES: Comments and related material...

  2. Development of Integrated Evaluation System for Severe Accident Management

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Ha; Kim, K. R.; Park, S. H.; Park, S. Y.; Park, J. H.; Song, Y. M.; Ahn, K. I.; Choi, Y

    2007-06-15

    The objective of the project is twofold. One is to develop a severe accident database (DB) for the Korean Standard Nuclear Power plant (OPR-1000) and a DB management system, and the other to develop a localized computer code, MIDAS (Multi-purpose IntegrateD Assessment code for Severe accidents). The MELCOR DB has been constructed for the typical representative sequences to support the previous MAAP DB in the previous phase. The MAAP DB has been updated using the recent version of MAAP 4.0.6. The DB management system, SARD, has been upgraded to manage the MELCOR DB in addition to the MAAP DB and the network environment has been constructed for many users to access the SARD simultaneously. The integrated MIDAS 1.0 has been validated after completion of package-wise validation. As the current version of MIDAS cannot simulate the anticipated transient without scram (ATWS) sequence, point-kinetics model has been implemented. Also the gap cooling phenomena after corium relocation into the RPV can be modeled by the user as an input parameter. In addition, the subsystems of the severe accident graphic simulator are complemented for the efficient severe accident management and the engine of the graphic simulator was replaced by the MIDAS instead of the MELCOR code. For the user's convenience, MIDAS input and output processors are upgraded by enhancing the interfacial programs.

  3. URBAN TRAFFIC ACCIDENT ANALYSIS BY USING GEOGRAPHIC INFORMATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Meltem SAPLIOĞLU

    2006-03-01

    Full Text Available In recent years, traffic accidents that cause more social and economic losses than that of natural disasters,have become a national problem in Turkey. To solve this problem and to reduce the casualties, road safety programs are tried to be developed. It is necessary to develop the most effective measures with low investment cost due to limited budgets allocated to such road safety programs. The most important program is to determine dangerous locations of traffic accidents and to improve these sections from the road safety view point. New Technologies are driving a cycle of continuous improvement that causes rapid changes in the traffic engineering and any engineering services within it. It is obvious that this developed services will be the potential for forward-thinking engineering studies to take a more influence role. In this study, Geographic Information System (GIS was used to identify the hazardous locations of traffic accidents in Isparta. Isparta city map was digitized by using Arcinfo 7.21. Traffic accident reports occurred between 1998-2002 were obtained from Directory of Isparta Traffic Region and had been used to form the database. Topology was set up by using Crash Diagrams and Geographic Position Reference Systems. Tables are formed according to the obtained results and interpreted.

  4. Development of Integrated Evaluation System for Severe Accident Management

    International Nuclear Information System (INIS)

    Kim, Dong Ha; Kim, K. R.; Park, S. H.; Park, S. Y.; Park, J. H.; Song, Y. M.; Ahn, K. I.; Choi, Y.

    2007-06-01

    The objective of the project is twofold. One is to develop a severe accident database (DB) for the Korean Standard Nuclear Power plant (OPR-1000) and a DB management system, and the other to develop a localized computer code, MIDAS (Multi-purpose IntegrateD Assessment code for Severe accidents). The MELCOR DB has been constructed for the typical representative sequences to support the previous MAAP DB in the previous phase. The MAAP DB has been updated using the recent version of MAAP 4.0.6. The DB management system, SARD, has been upgraded to manage the MELCOR DB in addition to the MAAP DB and the network environment has been constructed for many users to access the SARD simultaneously. The integrated MIDAS 1.0 has been validated after completion of package-wise validation. As the current version of MIDAS cannot simulate the anticipated transient without scram (ATWS) sequence, point-kinetics model has been implemented. Also the gap cooling phenomena after corium relocation into the RPV can be modeled by the user as an input parameter. In addition, the subsystems of the severe accident graphic simulator are complemented for the efficient severe accident management and the engine of the graphic simulator was replaced by the MIDAS instead of the MELCOR code. For the user's convenience, MIDAS input and output processors are upgraded by enhancing the interfacial programs

  5. Evaluation of severe accident risks: Quantification of major input parameters: MAACS [MELCOR Accident Consequence Code System] input

    International Nuclear Information System (INIS)

    Sprung, J.L.; Jow, H-N; Rollstin, J.A.; Helton, J.C.

    1990-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-12-01

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

  7. Intelligent system for accident identification in NPP

    International Nuclear Information System (INIS)

    Hernandez, J.L.

    1998-01-01

    Accidental situations in NPP are great concern for operators, the facility, regulatory bodies and the environmental. This work proposes a design of intelligent system aimed to assist the operator in the process of decision making initiator events with higher relative contribution to the reactor core damage occur. The intelligent System uses the results of the pre-operational Probabilistic safety Assessment and the Thermal hydraulic Safety Analysis of the NPP Juragua as source for building its knowledge base. The nucleus of the system is presented as a design of an intelligent hybrid from the combination of the artificial intelligence techniques fuzzy logic and artificial neural networks. The system works with variables from the process of the first circuit, second circuit and the containment and it is presented as a model for the integration of safety analyses in the process of decision making by the operator when tackling with accidental situations

  8. The cleansing of Vivitron after the gas system accident

    International Nuclear Information System (INIS)

    Helleboid, J.M.; Mac Cordick, J.

    1992-03-01

    A major accident in the gas transfer system of the Vivitron occurred in the gas-drying towers following a reactivation process of the alumina charge. This resulted in severe damage to various parts of the system and serious pollution of the entire Vivitron from degradation products of SF 6 . In consequence, all tests were ceased and extensive repairs and cleaning of the Vivitron were undertaken. This work is in progress and will expectedly be terminated by end of January 1992

  9. A Review of Accident Modelling Approaches for Complex Critical Sociotechnical Systems

    National Research Council Canada - National Science Library

    Qureshi, Zahid H

    2008-01-01

    .... This report provides a review of key traditional accident modelling approaches and their limitations, and describes new system-theoretic approaches to the modelling and analysis of accidents in safety-critical systems...

  10. System response of a DOE Defense Program package in a transportation accident environment

    International Nuclear Information System (INIS)

    Chen, T.F.; Hovingh, J.; Kimura, C.Y.

    1992-01-01

    The system response in a transportation accident environment is an element to be considered in an overall Transportation System Risk Assessment (TSRA) framework. The system response analysis uses the accident conditions and the subsequent accident progression analysis to develop the accident source term, which in turn, is used in the consequence analysis. This paper proposes a methodology for the preparation of the system response aspect of the TSRA

  11. The Use of Low-frequency Active Channel Signals in an Information Leakage Detection and Prevention Systems

    Directory of Open Access Journals (Sweden)

    A. V. Mamaev

    2011-06-01

    Full Text Available This article describes a solution for the protection of the temporary lifting of control over the target machine, while using information leakage detection and prevention systems. It is proposed to use a specially designed channel for alert’s signals through the computer’s power supply.

  12. Comparison of the Standard of Air Leakage in Current Metal Duct Systems in the World

    Science.gov (United States)

    Di, Yuhui; Wang, Jiqian; Feng, Lu; Li, Xingwu; Hu, Chunlin; Shi, Junshe; Xu, Qingsong; Qiao, Leilei

    2018-01-01

    Based on the requirements of air leakage of metal ducts in Chinese design standards, technical measures and construction standards, this paper compares the development history, the classification of air pressure levels and the air tightness levels of air leakage standards of current Chinese and international metal ducts, sums up the differences, finds shortage by investigating the design and construction status and access to information, and makes recommendations, hoping to help the majority of engineering and technical personnel.

  13. Implementation of an Analytical Model for Leakage Neutron Equivalent Dose in a Proton Radiotherapy Planning System

    Directory of Open Access Journals (Sweden)

    John Eley

    2015-03-01

    Full Text Available Equivalent dose from neutrons produced during proton radiotherapy increases the predicted risk of radiogenic late effects. However, out-of-field neutron dose is not taken into account by commercial proton radiotherapy treatment planning systems. The purpose of this study was to demonstrate the feasibility of implementing an analytical model to calculate leakage neutron equivalent dose in a treatment planning system. Passive scattering proton treatment plans were created for a water phantom and for a patient. For both the phantom and patient, the neutron equivalent doses were small but non-negligible and extended far beyond the therapeutic field. The time required for neutron equivalent dose calculation was 1.6 times longer than that required for proton dose calculation, with a total calculation time of less than 1 h on one processor for both treatment plans. Our results demonstrate that it is feasible to predict neutron equivalent dose distributions using an analytical dose algorithm for individual patients with irregular surfaces and internal tissue heterogeneities. Eventually, personalized estimates of neutron equivalent dose to organs far from the treatment field may guide clinicians to create treatment plans that reduce the risk of late effects.

  14. Fault Analysis and Solution on Bucket Dropping Accident in Hoisting System

    Directory of Open Access Journals (Sweden)

    Chunhui Liu

    2014-01-01

    Full Text Available Overwinding was the main accident in lifting systems of coal mine and bucket dropping accident was the most serious overwinding accident. According to the cause and mechanism of the bucket dropping accident in main shaft hoisting systems, the conclusion that overloading promotion was the main cause of bucket crash accident was obtained with the fault tree analysis method. One theoretical analysis model was established in order to prevent the occurrence of overloaded bucket dropping accident. The model provided scientific basis and steps in theory for qualitative and quantitative analysis on the cause of falling bucket accident and for the study on accident prediction and prevention. This article proposed several feasible technical measures to prevent the bucket crash accident, which had important guiding significance in practical application.

  15. A radiological accident consequence assessment system for Hong Kong

    International Nuclear Information System (INIS)

    Wong, M.C.; Lam, H.K.

    1993-01-01

    An account is given of the Hong Kong Radiological Accident Consequence Assessment System which would be used to assess the potential consequences of an emergency situation involving atmospheric release of radioactive material. The system has the capability to acquire real-time meteorological information from the Observatory's network of automatic stations, synoptic stations in the nearby region as well as forecast data from numerical prediction models. The system makes use of these data to simulate the transport and dispersion of the released radioactive material. The effectiveness of protective action on the local population is also modeled. The system serves as a powerful aid in the protective action recommendation processes

  16. FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Francisco; Larry Palmiter; Erin Kruse; Bob Davis

    2003-10-18

    Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind effects were minimal. Unfortunately, the time and difficulty of setup can be prohibitive, and it is likely that this method will not be practical for general use by contractors except in homes with no return ducts. The Delta-Q test was found to have a bias resulting in overprediction of the leakage, which qualitatively confirms the results of previous laboratory, simulation, and small-scale field studies. On average the bias was only a few percent of the air handler flow, but in about 20% of the homes the bias was large. A primary flaw with the Delta-Q test is the assumption that the pressure between the ducts and the house remain constant during the test, as this assumption does not hold true. Various modifications to the Delta-Q method were evaluated as

  17. Enhanced Accident Tolerant Fuels for LWRS - A Preliminary Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gilles Youinou; R. Sonat Sen

    2013-09-01

    The severe accident at Fukushima Daiichi nuclear plants illustrates the need for continuous improvements through developing and implementing technologies that contribute to safe, reliable and cost-effective operation of the nuclear fleet. Development of enhanced accident tolerant fuel contributes to this effort. These fuels, in comparison with the standard zircaloy – UO2 system currently used by the LWR industry, should be designed such that they tolerate loss of active cooling in the core for a longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, and design-basis events. This report presents a preliminary systems analysis related to most of these concepts. The potential impacts of these innovative LWR fuels on the front-end of the fuel cycle, on the reactor operation and on the back-end of the fuel cycle are succinctly described without having the pretension of being exhaustive. Since the design of these various concepts is still a work in progress, this analysis can only be preliminary and could be updated as the designs converge on their respective final version.

  18. Wet weather highway accident analysis and skid resistance data management system (volume II : user's manual).

    Science.gov (United States)

    1992-06-01

    The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

  19. Wet weather highway accident analysis and skid resistance data management system (volume I).

    Science.gov (United States)

    1992-06-01

    The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-12-01

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

  1. Denmark's planned nationwide warning system for fallout from nuclear accidents

    International Nuclear Information System (INIS)

    Walmod-Larsen, O.; Ryder, H.P.

    1988-01-01

    Denmark has no nuclear power plants, and has decided politically not to build any in the foreseeable future. However, within 150 km of its territory there are several plants in operation. After the Chernobyl accident, it was decided that the existing emergency plan for accidents at Sweden's Barsebaeck plant should be extended to cover the whole of Denmark, taking the above mentioned plants into consideration. Such a nation-wide emergency plan is now under preparation and is expected to be operational in 1989. Ten permanent, automatic, on-line monitoring stations are planned. The stations are required to be highly sensitive, able to detect an increase from man-made radioactivity of to 20 % of the usual natural radiation level. In case of an emergency, the ARGOS (Accident Reporting and Guiding Operational System) computer system will be connected to the central computer. ARGOS facilitates transmission, registration, evaluation and presentation of monitoring data from a large number of locations. The data are presented on color screens, prints or plots on suitable maps with the possibility of showing isocurves, population data and estimated doses. Another element in the proposed nation-wide emergency plan is the introduction of about 60 mobile radiation monitors, carried on vehicles or airborne, for use in alert situations. 1 ref., 1 fig

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-08-01

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

  3. Investigation of air cleaning system response to accident conditions

    International Nuclear Information System (INIS)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported

  4. Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Yim, Man S.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings.

  5. Anatomical evaluation of penile venous system by CT cavernosography in patients with erectile dysfunction and venous leakage

    Directory of Open Access Journals (Sweden)

    Ghafoori M

    2012-11-01

    Full Text Available Background: Erectile dysfunction is an important problem in men and an organic cause is found in about 50% of cases. When a vasculogenic etiology is suspected, imaging assessments are of great help. Cavernosography is traditionally recognized as an imaging modality for evaluation of venous leakage in men with impotency. We employed CT cavernosography as a novel technique for demonstrating penile venous anatomy and leaking veins.Methods: In the present case series study, we recruited 45 patients with erectile dysfunction by convenient sampling at Hazrat Rasoul Akram Hospital in Tehran, Iran, during one year (1390. The patients had previously been diagnosed with venous incompetency by Doppler study. After intracavernosal injection of prostaglandin E1, we injected sterile normal saline into the corpora cavernosa to achieve penile erection. Later, we injected contrast media into the corpus cavernosum, which was followed by CT scan of the penis and pelvic area to show the venous anatomy and leakage sites.Results: The mean age of the patients was 35.8±8.9 years. 36 (80% patients had venous leakage in crural veins, 27 (60% in cavernosal veins, 27 (60% in circumflex veins, 24 (52.3% in urethral veins, 21 (46.7% in deep dorsal vein, 3 (6.7% in para-arterial veins and 3 (6.7% in corpus spongiosum. Conclusion: The results of this study show the high prevalence of venous leakage in patients referring for erectile dysfunction. Moreover, CT cavernosography was shown to be a useful method for evaluating penile venous system and its related leakage sites which are important for surgical planning.

  6. The development of a nuclear accident risk information system

    International Nuclear Information System (INIS)

    Jeong, J. T.; Jeong, W. D.

    2001-01-01

    The computerized system NARIS (Nuclear Accident Risk Information System) was developed in order to support the estimation of health effects and the establishment the effective risk reduction strategies. Using the system, we can analyze the distribution of health effects easily by displaying the results on the digital map of the site. Also, the thematic mapping allows the diverse analyses of the distribution of the health effects. The NARIS can be used in the emergency operation facilities in order to analyze the distribution of the health effects resulting from the severe accidents of a nuclear power plant. Also, the rapid analysis of the health effect is possible by storing the health effect results in the form of a database. Therefore, the staffs of the emergency operation facilities can establish the rapid and effective emergency response strategies. The module for the optimization of the costs and benefits and the decision making support will be added. The technical support for the establishment of the optimum and effective emergency response strategies will be possible using this system

  7. A Modular Telerobot Control System for Accident Response

    International Nuclear Information System (INIS)

    Anderson, Robert J.; Shirey, David L.

    1999-01-01

    The Accident Response Mobile Manipulator System (ARMMS) is a teleoperated emergency response vehicle that deploys two hydraulic manipulators, five cameras, and an array of sensors to the scene of an incident. It is operated from a remote base station that can be situated up to four kilometers away from the site. Recently, a modular telerobot control architecture called SMART (Sandia's Modular Architecture for Robotic and Teleoperation) was applied to ARMMS to improve the precision, safety, and operability of the manipulators on board. Using SMART, a prototype manipulator control system was developed in a couple of days, and an integrated working system was demonstrated within a couple of months. New capabilities such as camera teleoperation, autonomous tool changeout and dual manipulator control have been incorporated. The final system incorporates twenty-two separate modules and implements eight different behavior modes. This paper describes the integration of SMART into the ARMMS system

  8. A Modular Telerobot Control System for Accident Response

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Robert J.; Shirey, David L.

    1999-07-20

    The Accident Response Mobile Manipulator System (ARMMS) is a teleoperated emergency response vehicle that deploys two hydraulic manipulators, five cameras, and an array of sensors to the scene of an incident. It is operated from a remote base station that can be situated up to four kilometers away from the site. Recently, a modular telerobot control architecture called SMART (Sandia's Modular Architecture for Robotic and Teleoperation) was applied to ARMMS to improve the precision, safety, and operability of the manipulators on board. Using SMART, a prototype manipulator control system was developed in a couple of days, and an integrated working system was demonstrated within a couple of months. New capabilities such as camera teleoperation, autonomous tool changeout and dual manipulator control have been incorporated. The final system incorporates twenty-two separate modules and implements eight different behavior modes. This paper describes the integration of SMART into the ARMMS system.

  9. Development of supporting system for emergency response to maritime transport accidents involving radioactive material

    International Nuclear Information System (INIS)

    Odano, N.; Matsuoka, T.; Suzuki, H.

    2004-01-01

    National Maritime Research Institute has developed a supporting system for emergency response of competent authority to maritime transport accidents involving radioactive material. The supporting system for emergency response has functions of radiation shielding calculation, marine diffusion simulation, air diffusion simulation and radiological impact evaluation to grasp potential hazard of radiation. Loss of shielding performance accident and loss of sealing ability accident were postulated and impact of the accidents was evaluated based on the postulated accident scenario. Procedures for responding to emergency were examined by the present simulation results

  10. New developments in the surveillance and diagnostics technology for vibration, structure-borne sound and leakage monitoring systems

    International Nuclear Information System (INIS)

    Gloth, Gerrit

    2009-01-01

    Monitoring and diagnostic systems are of main importance for a safe and efficient operation of nuclear power plants. The author describes new developments with respect to vibration monitoring with a functional extension in the time domain for den secondary circuit, the development of a local system for the surveillance of rotating machines, the structure-borne sound monitoring with improvement of event analysis, esp. the loose part locating, leakage monitoring with a complete system for humidity measurement, and the development of a common platform for all monitoring and diagnostic systems, that allows an efficient access for comparison and cross references.

  11. Research and development of a high-temperature helium-leak detection system (joint research). Part 1 survey on leakage events and current leak detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Sakaba, Nariaki; Nakazawa, Toshio; Kawasaki, Kozo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Urakami, Masao; Saisyu, Sadanori [Japan Atomic Power Co., Tokyo (Japan)

    2003-03-01

    In High Temperature Gas-cooled Reactors (HTGR), the detection of leakage of helium at an early stage is very important for the safety and stability of operations. Since helium is a colourless gas, it is generally difficult to identify the location and the amount of leakage when very little leakage has occurred. The purpose of this R and D is to develop a helium leak detection system for the high temperature environment appropriate to the HTGR. As the first step in the development, this paper describes the result of surveying leakage events at nuclear facilities inside and outside Japan and current gas leakage detection technology to adapt optical-fibre detection technology to HTGRs. (author)

  12. Development of the severe accident risk information database management system SARD

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Kwang Il; Kim, Dong Ha

    2003-01-01

    The main purpose of this report is to introduce essential features and functions of a severe accident risk information management system, SARD (Severe Accident Risk Database Management System) version 1.0, which has been developed in Korea Atomic Energy Research Institute, and database management and data retrieval procedures through the system. The present database management system has powerful capabilities that can store automatically and manage systematically the plant-specific severe accident analysis results for core damage sequences leading to severe accidents, and search intelligently the related severe accident risk information. For that purpose, the present database system mainly takes into account the plant-specific severe accident sequences obtained from the Level 2 Probabilistic Safety Assessments (PSAs), base case analysis results for various severe accident sequences (such as code responses and summary for key-event timings), and related sensitivity analysis results for key input parameters/models employed in the severe accident codes. Accordingly, the present database system can be effectively applied in supporting the Level 2 PSA of similar plants, for fast prediction and intelligent retrieval of the required severe accident risk information for the specific plant whose information was previously stored in the database system, and development of plant-specific severe accident management strategies.

  13. Development of ultrasonic high temperature system for severe accidents research

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Kil Mo; Kang, Kyung Ho; Kim, Young Ro and others

    2000-07-01

    The aims of this study are to find a gap formation between corium melt and the reactor lower head vessel, to verify the principle of the gap formation and to analyze the effect of the gap formation on the thermal behavior of corium melt and the lower plenum. This report aims at suggesting development of a new high temperature measuring system using an ultrasonic method which overcomes the limitations of the present thermocouple method used for severe accident experiments. Also, this report describes the design and manufacturing method of the ultrasonic system. At that time, the sensor element is fabricated to a reflective element using 1mm diameter and 50 mm and 80 mm long tungsten alloy wires. This temperature measuring system is intended to measure up to 2800 deg C.

  14. [a Monitoring System For Work-related Accidents In Piracicaba, São Paulo, Brazil].

    OpenAIRE

    Cordeiro, Ricardo; Vilela, Rodolfo Andrade Gouveia; de Medeiros, Maria Angélica Tavares; Gonçalves, Cláudia Giglio de Oliveira; Bragantini, Clarice Aparecida; Varolla, Antenor J; Celso, Stephan

    2015-01-01

    The authors report on the development of a work accident monitoring system in Piracicaba, São Paulo State, Brazil, with the following characteristics: information feeding the system is obtained in real time directly from accident treatment centers; the system has universal monitoring, covering all work-related accidents in Piracicaba, regardless of the nature of the worker's employment conditions, place of work, or place of residence; health surveillance and promotion of health initiatives ar...

  15. Overview of main accident parameters in car-to-cyclist accidents for use in AEB-system test protocol

    NARCIS (Netherlands)

    Uittenbogaard, J.; Camp, O.M.G.C. op den; Montfort, S. van

    2016-01-01

    The number of fatalities in road traffic accidents in Europe is decreasing. Unfortunately, the number of fatalities among cyclists does not follow this trend with the same rate [1]. The au-tomotive industry is making a significant effort in the development and implementation of safety systems in

  16. Supporting system in emergency response plan for nuclear material transport accidents

    International Nuclear Information System (INIS)

    Nakagome, Y.; Aoki, S.

    1993-01-01

    As aiming to provide the detailed information concerning nuclear material transport accidents and to supply it to the concerned organizations by an online computer, the Emergency Response Supporting System has been constructed in the Nuclear Safety Technology Center, Japan. The system consists of four subsystems and four data bases. By inputting initial information such as name of package and date of accident, one can obtain the appropriate initial response procedures and related information for the accident immediately. The system must be useful for protecting the public safety from nuclear material transport accidents. But, it is not expected that the system shall be used in future. (J.P.N.)

  17. A Biological-Realtime Neuromorphic System in 28 nm CMOS Using Low-Leakage Switched Capacitor Circuits.

    Science.gov (United States)

    Mayr, Christian; Partzsch, Johannes; Noack, Marko; Hänzsche, Stefan; Scholze, Stefan; Höppner, Sebastian; Ellguth, Georg; Schüffny, Rene

    2016-02-01

    A switched-capacitor (SC) neuromorphic system for closed-loop neural coupling in 28 nm CMOS is presented, occupying 600 um by 600 um. It offers 128 input channels (i.e., presynaptic terminals), 8192 synapses and 64 output channels (i.e., neurons). Biologically realistic neuron and synapse dynamics are achieved via a faithful translation of the behavioural equations to SC circuits. As leakage currents significantly affect circuit behaviour at this technology node, dedicated compensation techniques are employed to achieve biological-realtime operation, with faithful reproduction of time constants of several 100 ms at room temperature. Power draw of the overall system is 1.9 mW.

  18. A database system for the management of severe accident risk information, SARD

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, K. I.; Kim, D. H. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    The purpose of this paper is to introduce main features and functions of a PC Windows-based database management system, SARD, which has been developed at Korea Atomic Energy Research Institute for automatic management and search of the severe accident risk information. Main functions of the present database system are implemented by three closely related, but distinctive modules: (1) fixing of an initial environment for data storage and retrieval, (2) automatic loading and management of accident information, and (3) automatic search and retrieval of accident information. For this, the present database system manipulates various form of the plant-specific severe accident risk information, such as dominant severe accident sequences identified from the plant-specific Level 2 Probabilistic Safety Assessment (PSA) and accident sequence-specific information obtained from the representative severe accident codes (e.g., base case and sensitivity analysis results, and summary for key plant responses). The present database system makes it possible to implement fast prediction and intelligent retrieval of the required severe accident risk information for various accident sequences, and in turn it can be used for the support of the Level 2 PSA of similar plants and for the development of plant-specific severe accident management strategies.

  19. Coronal heating in coupled photosphere-chromosphere-coronal systems: turbulence and leakage

    Science.gov (United States)

    Verdini, A.; Grappin, R.; Velli, M.

    2012-02-01

    Context. Coronal loops act as resonant cavities for low-frequency fluctuations that are transmitted from the deeper layers of the solar atmosphere. These fluctuations are amplified in the corona and lead to the development of turbulence that in turn is able to dissipate the accumulated energy, thus heating the corona. However, trapping is not perfect, because some energy leaks down to the chromosphere on a long timescale, limiting the turbulent heating. Aims: We consider the combined effects of turbulence and energy leakage from the corona to the photosphere in determining the turbulent energy level and associated heating rate in models of coronal loops, which include the chromosphere and transition region. Methods: We use a piece-wise constant model for the Alfvén speed in loops and a reduced MHD-shell model to describe the interplay between turbulent dynamics in the direction perpendicular to the mean field and propagation along the field. Turbulence is sustained by incoming fluctuations that are equivalent, in the line-tied case, to forcing by the photospheric shear flows. While varying the turbulence strength, we systematically compare the average coronal energy level and dissipation in three models with increasing complexity: the classical closed model, the open corona, and the open corona including chromosphere (or three-layer model), with the last two models allowing energy leakage. Results: We find that (i) leakage always plays a role. Even for strong turbulence, the dissipation time never becomes much lower than the leakage time, at least in the three-layer model; therefore, both the energy and the dissipation levels are systematically lower than in the line-tied model; (ii) in all models, the energy level is close to the resonant prediction, i.e., assuming an effective turbulent correlation time longer than the Alfvén coronal crossing time; (iii) the heating rate is close to the value given by the ratio of photospheric energy divided by the Alfv

  20. Assessment of pleural air leakage using digital chest drainage system after surgical pulmonary resection: Comparison of visible alveolar air leakage with the digital value measured by a digital chest drainage system.

    Directory of Open Access Journals (Sweden)

    Ryo Mori

    Full Text Available The sensitivity of postoperative pleural air leakage (PAL after pulmonary resection is evaluated by a simple subjective grading method in clinical practice. A new electronic digital chest drainage evaluation system (DCS recently became clinically available. This study was designed to evaluate the clinical application of the DCS in monitoring the airflow volume and managing postoperative PAL.We prospectively enrolled 25 patients who underwent pulmonary resection. Postoperative PAL was evaluated using both conventional PAL grading based on the physician's visual judgment (analog chest drainage evaluation system [ACS]: Level 0 = no leakage to 4 = continuous leakage and the DCS. The DCS digital measurement was recorded as the flow volume (ml/min, which was taken once daily from postoperative day 1 to the day of chest drainage tube removal.In total, 45 measurements were performed on 25 patients during the evaluation period. Postoperative PAL was observed in five patients (20.0% and judged as ACS Level >1. The mean DCS values corresponding to ACS Levels 0, 1, 2, and 3 were 2.42 (0.0-11.3, 48.6 (35.4-67.9, 95.6 (79.7-111.5, and 405.3 (150.3-715.6, respectively. The Spearman correlation test showed a significant positive correlation between the ACS PAL level and DCS flow volume (R = 0.8477, p < 0.001.A relationship between the visual PAL level by the ACS and the digital value by the DCS was identified in this study. The numeric volume obtained by the DCS has been successful in information-sharing with all staff. The digital PAL value evaluated by the DCS is appropriate, and the use of the DCS is promising in the treatment of postoperative PAL after pulmonary resection.

  1. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Directory of Open Access Journals (Sweden)

    Fang Yan

    Full Text Available Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie analysis was proposed by mapping bow-tie analysis into Bayesian network (BN. Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  2. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  3. 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.

  4. A severe accident analysis for the system-integrated modular advanced reactor

    International Nuclear Information System (INIS)

    Jung, Gunhyo; Jae, Moosung

    2015-01-01

    The System-Integrated Modular Advanced Reactor (SMART) that has been recently designed in KOREA and has acquired standard design certification from the nuclear power regulatory body (NSSC) is an integral type reactor with 330MW thermal power. It is a small sized reactor in which the core, steam generator, pressurizer, and reactor coolant pump that are in existing pressurized light water reactors are designed to be within a pressure vessel without any separate pipe connection. In addition, this reactor has much different design characteristics from existing pressurized light water reactors such as the adoption of a passive residual heat removal system and a cavity flooding system. Therefore, the safety of the SMART against severe accidents should be checked through severe accident analysis reflecting the design characteristics of the SMART. For severe accident analysis, an analysis model has been developed reflecting the design information presented in the standard design safety analysis report. The severe accident analysis model has been developed using the MELCOR code that is widely used to evaluate pressurized LWR severe accidents. The steady state accident analysis model for the SMART has been simulated. According to the analysis results, the developed model reflecting the design of the SMART is found to be appropriate. Severe accident analysis has been performed for the representative accident scenarios that lead to core damage to check the appropriateness of the severe accident management plan for the SMART. The SMART has been shown to be safe enough to prevent severe accidents by utilizing severe accident management systems such as a containment spray system, a passive hydrogen recombiner, and a cavity flooding system. In addition, the SMART is judged to have been technically improved remarkably compared to existing PWRs. The SMART has been designed to have a larger reactor coolant inventory compared to its core's thermal power, a large surface area in

  5. New Belgian position on containment leakage testing

    International Nuclear Information System (INIS)

    De Boeck, B.

    1986-01-01

    The containment leakage testing requirements (up to now 10 CFR 50 App. J) have recently been reevaluated in Belgium. The criterion for type A tests at half the accident pressure has been strengthened, but the periodicity has been relaxed. New overall leakage test at very low overpressure have been required after each extended cold shutdown period. A few items of the procedure for type A tests have been modified. It is felt that the new requirements improve the safety but also lower the burden of the containment leakage tests. Experimental results from tests performed in 1985 at Tihange reactor and Doel unit 3 are presented

  6. Accident Tolerant Reactor Shutdown for NTP Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In brief, USNC's accident submersion safe drums are control drums where a small amount of fuel is added opposite to the neutron absorber and the drums impinge on the...

  7. Accident Data Use and Geographic Information System (GIS)

    Science.gov (United States)

    1998-09-16

    Project Description: The Cheyenne Area Transportation Planning Process (ChATTP) : has developed a PowerPoint presentation demonstrating how to use an existing : accident database with GIS software. The slides are followed by a hands-on : demonstratio...

  8. Effect of diesel leakage in circulating cooling water system on preponderant bacteria diversity and bactericidal effect of biocides.

    Science.gov (United States)

    Zhong, Huiyun; Liu, Fang; Lu, Jinjin; Yang, Wei; Zhao, Chaocheng

    2015-01-01

    Petroleum products leakage results in adverse effect on the normal operation of a circulating cooling water system. However, relatively little research has been done to explore the effect of petroleum products leakage on circulating cooling water quality and biofilm preponderant bacteria diversity. Also, normal biocides application modes cannot fulfil the need for biofilm control. In this study, diesel oil was used as the experimental subject representing leaking petroleum products; the effect of diesel addition on biofilm preponderant bacteria diversity and the bactericidal effect of chlorine dioxide and tetradecyl dimethyl benzyl ammonium chloride (1427) was investigated. Bacterial community structures were examined by PCR-denaturing gradient gel electrophoresis and PCR cloning of 16S rDNA genes. Except for 100 mg/L diesel, increasing diesel concentration enhanced the biofilm detachment ratio compared with the control test. The microstructure of biofilm samples with 0, 300 and 900 mg/L diesel addition was observed. The species of preponderant bacteria in the biofilm sample with 300 mg/L diesel addition were more and the bacterial distribution was more uniform than those in the biofilm sample with 900 mg/L diesel addition. With ClO2 and 1427 addition, chemical oxygen demand increased, lipid phosphorus and bacterial count first decreased and then remained stable, and the bactericidal ratio first increased and then remained stable. Diesel addition variation has more obvious effect on ClO2 than 1427.

  9. A Proposed Scalable Design and Simulation of Wireless Sensor Network-Based Long-Distance Water Pipeline Leakage Monitoring System

    Directory of Open Access Journals (Sweden)

    Abdulaziz S. Almazyad

    2014-02-01

    Full Text Available Anomalies such as leakage and bursts in water pipelines have severe consequences for the environment and the economy. To ensure the reliability of water pipelines, they must be monitored effectively. Wireless Sensor Networks (WSNs have emerged as an effective technology for monitoring critical infrastructure such as water, oil and gas pipelines. In this paper, we present a scalable design and simulation of a water pipeline leakage monitoring system using Radio Frequency IDentification (RFID and WSN technology. The proposed design targets long-distance aboveground water pipelines that have special considerations for maintenance, energy consumption and cost. The design is based on deploying a group of mobile wireless sensor nodes inside the pipeline and allowing them to work cooperatively according to a prescheduled order. Under this mechanism, only one node is active at a time, while the other nodes are sleeping. The node whose turn is next wakes up according to one of three wakeup techniques: location-based, time-based and interrupt-driven. In this paper, mathematical models are derived for each technique to estimate the corresponding energy consumption and memory size requirements. The proposed equations are analyzed and the results are validated using simulation.

  10. A practical approach to estimate diffusional leakages of leaf chamber of open gas exchange systems using intact leaves.

    Science.gov (United States)

    Kitao, Mitsutoshi; Harayama, Hisanori; Uemura, Akira

    2017-11-01

    We propose a novel approach to determine the coefficient of CO 2 diffusional leakage (k _CO2 ) in the chamber of a portable open gas exchange system (Li-6400, Li-Cor Inc., NE, USA) using intact leaves. Assuming that dark respiration rate (R n ) is constant at various CO 2 concentrations, at least in a short term, k _CO2 should be the value that makes the leak-corrected R n constant. We used 2 representative tree species native to northern Japan, Japanese white birch (Betula platyphylla var. japonica) and Japanese oak (Quercus mongolica var. crispula), to determine k _CO2 , by measuring R n at various CO 2 concentrations. Irrespective of the species, k _CO2 estimated by the present approach was well correlated with the diffusional leak coefficient (k _flow ) estimated by the generally used approach that utilizes CO 2 concentrations inside and outside the chamber based on thermally killed leaves at various flow rates. Furthermore, the present approach does not require the ambient CO 2 concentration outside the chamber (C a ) if C a in the laboratory is stable, which provides a feasible way to correct the photosynthetic rate, taking diffusional leakage into account. © 2017 John Wiley & Sons Ltd.

  11. Off-gas and air cleaning systems for accident conditions in nuclear power plants

    International Nuclear Information System (INIS)

    1993-01-01

    This report surveys the design principles and strategies for mitigating the consequences of abnormal events in nuclear power plants by the use of air cleaning systems. Equipment intended for use in design basis accident and severe accident conditions is reviewed, with reference to designs used in IAEA Member States. 93 refs, 48 figs, 23 tabs

  12. Analysis of Waste Leak and Toxic Chemical Release Accidents from Waste Feed Delivery (WFD) Diluent System

    Energy Technology Data Exchange (ETDEWEB)

    WILLIAMS, J.C.

    2000-09-15

    Radiological and toxicological consequences are calculated for 4 postulated accidents involving the Waste Feed Delivery (WFD) diluent addition systems. Consequences for the onsite and offsite receptor are calculated. This analysis contains technical information used to determine the accident consequences for the River Protection Project (RPP) Final Safety Analysis Report (FSAR).

  13. Analysis of Waste Leak and Toxic Chemical Release Accidents from Waste Feed Delivery (WFD) Diluent System

    International Nuclear Information System (INIS)

    WILLIAMS, J.C.

    2000-01-01

    Radiological and toxicological consequences are calculated for 4 postulated accidents involving the Waste Feed Delivery (WFD) diluent addition systems. Consequences for the onsite and offsite receptor are calculated. This analysis contains technical information used to determine the accident consequences for the River Protection Project (RPP) Final Safety Analysis Report (FSAR)

  14. The causing model of accidents and preventing system of small mines

    Energy Technology Data Exchange (ETDEWEB)

    Cao, S.; Zhang, L.; Liu, Y.; Li, Y. [Chongqing University, Chongqing (China)

    2008-06-15

    From an analysis of data on fatal accidents in small coal mines in a southern region of China over a period of three years, the time and type of accidents was discussed by applying statistical methods. It is shown that accidents frequently occur at the end of spring and all through summer. Roof accidents and gas disasters constitute severe accidents and traffic accidents are also important. It was found that most accidents are caused by dangerous behaviour of personnel and the unsafe state of equipment combined with economic interest. The three-factor causing model (TFC model) was proposed. Unsafe behaviour is a direct cause influenced by staff and workers while the unsafe nature of equipment is an indirect cause of accidents influence by natural conditions and the level of technical equipment in the mines. A system of accident prevention in small coal collieries was established with the TFC model. In this, scientific management is an important factor. 13 refs., 4 figs., 1 tab.

  15. Nuclear-station post-accident liquid-sampling system: developed by Duke Power Company

    International Nuclear Information System (INIS)

    Burton, D.A.; Birch, M.L.; Orth, W.C.

    1981-01-01

    The accident at Three Mile Island showed that means must be provided to determine the radioactivity levels in high activity liquid and gaseous systems of a nuclear power plant without undue radiation exposure to personnel. The Duke Power Post Accident Liquid Sampling System provides the means for obtaining diluted liquid samples and diluted dissolved gas samples following a reactor accident involving substantial core damage. Their approach yields a straightforward engineering solution at a fraction of the cost of other systems. A description of the system, general design criteria, and color coded flow diagrams are included

  16. Factors correlated with traffic accidents as a basis for evaluating Advanced Driver Assistance Systems.

    Science.gov (United States)

    Staubach, Maria

    2009-09-01

    This study aims to identify factors which influence and cause errors in traffic accidents and to use these as a basis for information to guide the application and design of driver assistance systems. A total of 474 accidents were examined in depth for this study by means of a psychological survey, data from accident reports, and technical reconstruction information. An error analysis was subsequently carried out, taking into account the driver, environment, and vehicle sub-systems. Results showed that all accidents were influenced by errors as a consequence of distraction and reduced activity. For crossroad accidents, there were further errors resulting from sight obstruction, masked stimuli, focus errors, and law infringements. Lane departure crashes were additionally caused by errors as a result of masked stimuli, law infringements, expectation errors as well as objective and action slips, while same direction accidents occurred additionally because of focus errors, expectation errors, and objective and action slips. Most accidents were influenced by multiple factors. There is a safety potential for Advanced Driver Assistance Systems (ADAS), which support the driver in information assimilation and help to avoid distraction and reduced activity. The design of the ADAS is dependent on the specific influencing factors of the accident type.

  17. System-Level Analysis Modeling of Impacts of Operation Schemes of Geologic Carbon Dioxide Storage on Deep Groundwater and Carbon Dioxide Leakage Risk

    Science.gov (United States)

    Park, S.; Lee, S.; Park, J.; Kim, J.; Kihm, J.

    2013-12-01

    The objectives of this study are to predict quantitatively groundwater and carbon dioxide flow in deep saline sandstone aquifers under various carbon dioxide injection schemes (injection rate, injection period) and to analyze integratively impacts of such carbon dioxide injection schemes on deep groundwater (brine) and carbon dioxide leakage risk through abandoned wells or faults. In order to achieve the first objective, a series of process-level prediction modeling of groundwater and carbon dioxide flow in a deep saline sandstone aquifer under several carbon dioxide injection schemes was performed using a multiphase thermo-hydrological numerical model TOUGH2 (Pruess et al., 1999). The prediction modeling results show that the extent of carbon dioxide plume is significantly affected by such carbon dioxide injection schemes. In order to achieve the second objective, a series of system-level analysis modeling of deep groundwater and carbon dioxide leakage risk through an abandoned well or a fault under several carbon dioxide injection schemes was then performed using a brine and carbon dioxide leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault increase as the carbon dioxide injection rate increases. However, the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault decrease as the carbon dioxide injection period increases. These system-level analysis modeling results for deep groundwater and carbon dioxide leakage risk can be utilized as baseline data for establishing guidelines to mitigate anticipated environmental adverse effects on shallower groundwater systems (aquifers) when deep groundwater and carbon dioxide leakage occur. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute

  18. Review of current status for designing severe accident management support system

    International Nuclear Information System (INIS)

    Jeong, Kwang Sub

    2000-05-01

    The development of operator support system (OSS) is ongoing in many other countries due to the complexity both in design and in operation for nuclear power plant. The computerized operator support system includes monitoring of some critical parameters, early detection of plant transient, monitoring of component status, plant maintenance, and safety parameter display, and the operator support system for these areas are developed and are being used in some plants. Up to now, the most operator support system covers the normal operation, abnormal operation, and emergency operation. Recently, however, the operator support system for severe accident is to be developed in some countries. The study for the phenomena of severe accident is not performed sufficiently, but, based on the result up to now, the operator support system even for severe accident will be developed in this study. To do this, at first, the current status of the operator support system for normal/abnormal/emergency operation is reviewed, and the positive aspects and negative aspects of systems are analyzed by their characteristics. And also, the major items that should be considered in designing the severe accident operator support system are derived from the review. With the survey of domestic and foreign operator support systems, they are reviewed in terms of the safety parameter display system, decision-making support system, and procedure-tracking system. For the severe accident, the severe accident management guideline (SAMG) which is developed by Westinghouse is reviewed; the characteristics, structure, and logical flow of SAMG are studied. In addition, the critical parameters for severe accident, which are the basis for operators decision-making in severe accident management and are supplied to the operators and the technical support center, are reviewed, too

  19. Analysis of Fukushima unit 2 accident considering the operating conditions of RCIC system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Il, E-mail: sikim@kaeri.re.kr; Park, Jong Hwa; Ha, Kwang Soon; Cho, Song-Won; Song, JinHo

    2016-03-15

    Highlights: • Fukushima unit 2 accident was analyzed using MELCOR 1.8.6. • RCIC operating conditions were assumed and best case was selected. • Effect of RCIC operating condition on accident scenario was found. - Abstract: A severe accident in Fukushima occurred on March 11, 2011 and units 1, 2 and 3 were damaged severely. A tsunami following an earthquake made the supply of electricity power stop, and the safety systems, which use AC or DC power in plants could not operate properly. It is supposed that the degree of core degradation of unit 2 is less serious than in the other plants, and it was estimated that the operation of reactor core isolation cooling (RCIC) system at the initial stage of the accident minimized the core damage through decay heat removal. Although the operating conditions of the RCIC system are not known clearly, it can be important to analyze the accident scenario of unit 2. In this study, best case of the Fukushima unit 2 accident was presented considering the operating conditions of the RCIC system. The effects of operating condition on core degradation and fission product release rate to environment were also examined. In addition, importance of torus room flooding level in the accident analysis was discussed. MELCOR 1.8.6 was used in this research, and the geometries of plant and operating conditions of safety system were obtained from TEPCO through OECD/NEA BSAF Project.

  20. Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T. [KAIST, Daejeon (Korea, Republic of); Lee, So I. [KHNP CRI, Daejeon (Korea, Republic of)

    2014-10-15

    According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident.

  1. Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

    International Nuclear Information System (INIS)

    Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T.; Lee, So I.

    2014-01-01

    According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident

  2. Sisifo-gas a computerised system to support severe accident training and management

    International Nuclear Information System (INIS)

    Castro, A.; Buedo, J.L.; Borondo, L.; Lopez, N.

    2001-01-01

    Nuclear Power Plants (NPP) will have to be prepared to face the management of severe accidents, through the development of Severe Accident Guides and sophisticated systems of calculation, as a supporting to the decision-making. SISIFO-GAS is a flexible computerized tool, both for the supporting to accident management and for education and training in severe accident. It is an interactive system, a visual and an easily handle one, and needs no specific knowledge in MAAP code to make complicate simulations in conditions of severe accident. The system is configured and adjusted to work in a BWR/6 technology plant with Mark III Containment, as it is Cofrentes NPP. But it is easily portable to every other kind of reactor, having the level 2 PSA (probabilistic safety analysis) of the plant to be able to establish the categories of the source term and the most important sequences in the progression of the accident. The graphic interface allows following in a very intuitive and formative way the evolution and the most relevant events in the accident, in the both system's way of work, training and management. (authors)

  3. Causative Chain Difference for each Type of Accidents in Japanese Maritime Traffic Systems (MTS

    Directory of Open Access Journals (Sweden)

    Wanginingastuti Mutmainnah

    2017-09-01

    Full Text Available Causative chain (CC is a failure chain that cause accident as an outcome product of the second step of MOP model, namely line relation analysis (LRA. This CC is a connection of several causative factors (CF, an outcome product of first step of MOP model, namely corner analysis (CA. MOP Model is an abbreviation from 4M Overturned Pyramid, created by authors by combining 2 accident analysis models. There are two steps in this model, namely CA and LRA. Utilizing this model can know what is CF that happen dominantly to the accidents and what is a danger CC that characterize accidents in a certain place and certain period. By knowing the characteristics, the preventive action can be decided to decrease the number of accident in the next period. The aim of this paper is providing the development of MOP Model that has been upgraded and understanding the characteristics of each type accident. The data that is analyzed in this paper is Japanese accidents from 2008 until 2013, which is available on Japan Transportation Safety Board (JTSB’s website. The analysis shows that every type of accidents has a unique characteristic, shown by their CFs and CCs. However, Man Factor is still playing role to the system dominantly.

  4. A radioactive waste transportation package monitoring system for normal transport and accident emergency response conditions

    International Nuclear Information System (INIS)

    Brown, G.S.; Cashwell, J.W.; Apple, M.L.

    1993-01-01

    This paper addresses spent fuel and high level waste transportation history and prospects, discusses accident histories of radioactive material transport, discusses emergency responder needs and provides a general description of the Transportation Intelligent Monitoring System (TRANSIMS) design. The key objectives of the monitoring system are twofold: (1) to facilitate effective emergency response to accidents involving a radioactive waste transportation package, while minimizing risk to the public and emergency first-response personnel, and (2) to allow remote monitoring of transportation vehicle and payload conditions to enable research into radioactive material transportation for normal and accident conditions. (J.P.N.)

  5. The scenario-based system of workers training to prevent accidents during decommissioning of nuclear facilities

    International Nuclear Information System (INIS)

    Jeong, KwanSeong; Choi, ByungSeon; Moon, JeiKwon; Hyun, DongJun; Lee, JongHwan; Kim, IkJune; Kim, GeunHo; Seo, JaeSeok

    2014-01-01

    Highlights: • This paper is meant to develop the training system to prevent accidents during decommissioning of nuclear facilities. • Requirements of the system were suggested. • Data management modules of the system were designed. • The system was developed on virtual reality environment. - Abstract: This paper is meant to develop the training system to prevent accidents during decommissioning of nuclear facilities. Requirements of the system were suggested. Data management modules of the system were designed. The system was developed on virtual reality environment. The performance test of the system was proved to be appropriate to decommissioning of nuclear facilities

  6. Human error analysis of commercial aviation accidents using the human factors analysis and classification system (HFACS)

    Science.gov (United States)

    2001-02-01

    The Human Factors Analysis and Classification System (HFACS) is a general human error framework : originally developed and tested within the U.S. military as a tool for investigating and analyzing the human : causes of aviation accidents. Based upon ...

  7. System 80+TM PRA insights on severe accident prevention and mitigation

    International Nuclear Information System (INIS)

    Finnicum, D.J.; Jacob, M.C.; Schneider, R.E.; Weston, R.A.

    2004-01-01

    The System 80 + design is ABB-CE's standardized evolutionary Advanced Light Water Reactor (ALWR) design. It incorporates design enhancements based on Probabilistic Risk Assessment (PRA) insights, guidance from the ALWR Utility Requirements Document (URD), and US NRC's Severe Accident Policy. Major severe accident prevention and mitigation design features of the System 80 + design are described. The results of the System 80 + PRA are presented and the insights gained from the PRA sensitivity analyses are discussed. ABB-CE considered defense-in-depth for accident prevention and mitigation early in the design process and used robust design features to ensure that the System 80 + design achieved a low core damage frequency, low containment conditional failure probability, and excellent deterministic containment performance under severe accident conditions and to ensure that the risk was properly allocated among design features and between prevention and mitigation. (author)

  8. Radiation protection service for a nucleonic control system of continuous casting plant after events of accident

    International Nuclear Information System (INIS)

    Chakrabarti, Santanu; Massand, O.P.

    1998-01-01

    Extensive use of nucleonic control systems like level controllers was observed during radiation protection surveys in industries such as refineries, steel plants etc., located in the eastern region of India. There were two accidents at continuous casting plant in 1995 which affected the nucleonic control system installed in 1992. The authorities contacted Bhabha Atomic Research Centre (BARC) for radiation protection surveys for the involved nucleonic gauges. The present paper describes the radiation protection services rendered by BARC during such accidents. (author)

  9. Analysis of helium purification system capability during water ingress accident in RDE

    Science.gov (United States)

    Sriyono; Kusmastuti, Rahayu; Bakhri, Syaiful; Sunaryo, Geni Rina

    2018-02-01

    The water ingress accident caused by steam generator tube rupture (SGTR) in RDE (Experimental Power Reactor) must be anticipated. During the accident, steam from secondary system diffused and mixed with helium gas in the primary coolant. To avoid graphite corrosion in the core, steam will be removed by Helium purification system (HPS). There are two trains in HPS, first train for normal operation and the second for the regeneration and accident. The second train is responsible to clean the coolant during accident condition. The second train is equipped with additional component, i.e. water cooler, post accident blower, and water separator to remove this mixture gas. During water ingress, the water release from rupture tube is mixed with helium gas. The water cooler acts as a steam condenser, where the steam will be separated by water separator from the helium gas. This paper analyses capability of HPS during water ingress accident. The goal of the research is to determine the time consumed by HPS to remove the total amount of water ingress. The method used is modelling and simulation of the HPS by using ChemCAD software. The BDBA and DBA scenarios will be simulated. In BDBA scenario, up to 110 kg of water is assumed to infiltrate to primary coolant while DBA is up to 35 kg. By using ChemCAD simulation, the second train will purify steam ingress maximum in 0.5 hours. The HPS of RDE has a capability to anticipate the water ingress accident.

  10. Natural hazard impacts on transport systems: analyzing the data base of transport accidents in Russia

    Science.gov (United States)

    Petrova, Elena

    2015-04-01

    We consider a transport accident as any accident that occurs during transportation of people and goods. It comprises of accidents involving air, road, rail, water, and pipeline transport. With over 1.2 million people killed each year, road accidents are one of the world's leading causes of death; another 20-50 million people are injured each year on the world's roads while walking, cycling, or driving. Transport accidents of other types including air, rail, and water transport accidents are not as numerous as road crashes, but the relative risk of each accident is much higher because of the higher number of people killed and injured per accident. Pipeline ruptures cause large damages to the environment. That is why safety and security are of primary concern for any transport system. The transport system of the Russian Federation (RF) is one of the most extensive in the world. It includes 1,283,000 km of public roads, more than 600,000 km of airlines, more than 200,000 km of gas, oil, and product pipelines, 115,000 km of inland waterways, and 87,000 km of railways. The transport system, especially the transport infrastructure of the country is exposed to impacts of various natural hazards and weather extremes such as heavy rains, snowfalls, snowdrifts, floods, earthquakes, volcanic eruptions, landslides, snow avalanches, debris flows, rock falls, fog or icing roads, and other natural factors that additionally trigger many accidents. In June 2014, the Ministry of Transport of the RF has compiled a new version of the Transport Strategy of the RF up to 2030. Among of the key pillars of the Strategy are to increase the safety of the transport system and to reduce negative environmental impacts. Using the data base of technological accidents that was created by the author, the study investigates temporal variations and regional differences of the transport accidents' risk within the Russian federal regions and a contribution of natural factors to occurrences of different

  11. Evaluation of severe accident safety system value based on averting financial risks

    International Nuclear Information System (INIS)

    Hatch, S.W.; Benjamin, A.S.; Bennett, P.R.

    1983-01-01

    The Severe Accident Risk Reduction Program is being performed to benchmark the risks from nuclear power plants and to assess the benefits and impacts of a set of severe accident safety features. This paper describes the program in general and presents some preliminary results. These results include estimates of the financial risks associated with the operation of six reference plants and the value of severe accident prevention and mitigation safety systems in averting these risks. The results represent initial calculations and will be iterated before being used to support NRC decisions

  12. Evaluation of severe accident safety system value based on averting financial risks. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, S.W.; Bennett, P.R.; Benjamin, A.S.

    1983-01-01

    The Severe Accident Risk Reduction Program is being performed to benchmark the risks from nuclear power plants and to assess the benefits and impacts of a set of severe accident safety features. This paper describes the program in general and presents some preliminary results. These results include estimates of the financial risks associated with the operation of six reference plants and the value of severe accident prevention and mitigation safety systems in averting these risks. The results represent initial calculations and will be iterated before being used to support NRC decisions.

  13. HOW TO MINIMIZE OCCUPATIONAL ACCIDENTS IN TURKEY: THE BONUS-MALUS SYSTEM

    Directory of Open Access Journals (Sweden)

    Bülent ALTUNKAYNAK

    2016-01-01

    Full Text Available This study suggests Bonus-Malus System (BMS to minimize the occupational accidents in Turkey. Having a 12-class structure with a specific premium ratio for each class considering the number of accidents, the suggested system depends on the principle that the premium ratios should vary according to the number of accidents occurring in a given business. To enter the system, all businesses start from class 6, with a premium ratio of 2%. For the calculation of premium ratios for each class, the expected value principle is used. It is observed by using Markov chains that the system reaches the steady state in 45 years’ time and the changes in the premium income of Social Security Institution (SSI according to the distribution of businesses according to accident in the 5th, 10th, 20th, and 45th years are investigated. As a result, it is seen that the premium income of SSI will, in the course of time, decrease with BMS. In return, it is predicted that business are likely to try to escape punishment and turn to reward and increase measures against occupational accidents with a decrease in the number of accidents.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

  15. Application of GIS in prediction and assessment system of off-site accident consequence for NPP

    International Nuclear Information System (INIS)

    Wang Xingyu; Shi Zhongqi

    2002-01-01

    The assessment and prediction software system of off-site accident consequence for Guangdong Nuclear Power Plant (GNARD2.0) is a GIS-based software system. The spatial analysis of radioactive materials and doses with geographic information is available in this system. The structure and functions of the GNARD system and the method of applying ArcView GIS are presented

  16. Classification Of Road Accidents From The Perspective Of Vehicle Safety Systems

    Directory of Open Access Journals (Sweden)

    Jirovský Václav

    2015-11-01

    Full Text Available Modern road accident investigation and database structures are focused on accident analysis and classification from the point of view of the accident itself. The presented article offers a new approach, which will describe the accident from the point of view of integrated safety vehicle systems. Seven main categories have been defined to specify the level of importance of automated system intervention. One of the proposed categories is a new approach to defining the collision probability of an ego-vehicle with another object. This approach focuses on determining a 2-D reaction space, which describes all possible positions of the vehicle or other moving object in the specified amount of time in the future. This is to be used for defining the probability of the vehicles interacting - when the intersection of two reaction spaces exists, an action has to be taken on the side of ego-vehicle. The currently used 1-D quantity of TTC (time-to-collision can be superseded by the new reaction space variable. Such new quantity, whose basic idea is described in the article, enables the option of counting not only with necessary braking time, but mitigation by changing direction is then easily feasible. Finally, transparent classification measures of a probable accident are proposed. Their application is highly effective not only during basic accident comparison, but also for an on-board safety system.

  17. Accident Prevention and Diagnostics of Underground Pipeline Systems

    Science.gov (United States)

    Trokhimchuk, M.; Bakhracheva, Y.

    2017-11-01

    Up to forty thousand accidents occur annually with underground pipelines due to corrosion. The comparison of the methods for assessing the quality of anti-corrosion coating is provided. It is proposed to use the device to be tied-in to existing pipeline which has a higher functionality in comparison with other types of the devices due to the possibility of tie-in to the pipelines with different diameters. The existing technologies and applied materials allow us to organize industrial production of the proposed device.

  18. The leakage problem in vacuum system. Realization of a mass spectrometer detecting leaks

    International Nuclear Information System (INIS)

    Geller, R.

    1954-11-01

    In the first part of this paper we consider the problem of leaks in vacuum systems, and their detection. We consider in particular the method of detection by means of a helium spectrometer. The second part deals with the experimental set p. The analyser and the ion source have been studied in great detail, and we have also discussed the technological and mechanical aspects of the apparatus and its performances. (author) [fr

  19. Minimizing Systemic Leakage of Cisplatin during Percutaneous Isolated Pancreas Perfusion Chemotherapy: A Pilot Study.

    Science.gov (United States)

    Murata, Satoru; Onozawa, Shiro; Mine, Takahiko; Ueda, Tatsuo; Sugihara, Fumie; Yasui, Daisuke; Kumita, Shin-ichiro; Shimizu, Akira; Satake, Mitsuo

    2015-07-01

    To evaluate the feasibility of percutaneous isolated pancreas perfusion (PIPP) by using a pig model. All experiments were approved by the institutional Animal Experiment Ethics Committee. Fifteen pigs were assigned to five groups, and PIPP was performed. Angiographic and dye injection studies were performed to confirm the patency of the PIPP system (group 1). Blood that contained cisplatin (1.5 mg per kilogram of body weight) in an extracorporeal circuit was circulated through the pancreas at three infusion rates (40, 60, and 80 mL/min) to determine the optimal infusion rate in terms of safety and pharmacologic effectiveness (groups 2, 3, and 4, respectively). Chronological laboratory data and histologic findings were assessed in group 5, which received the optimal infusion rate. Maximum platinum concentration (Cmax) and area under the platinum concentration-time curve were compared by using the Kruskal-Wallis and Mann-Whitney U tests. Angiography and dye injection confirmed the patency of the PIPP system. Histopathologic examinations showed no abnormalities in the pancreas or other organs at a 40 mL/min infusion rate of cisplatin. However, edematous changes in the pancreas were observed at higher infusion rates. The pharmacologic effectiveness did not differ significantly among groups; therefore, the optimal infusion rate of 40 mL/min was selected. The median pancreatic-to-systemic exposure ratios were 71.8 for Cmax and 54.8 for the area under the curve. All laboratory data remained normal or returned to pretreatment levels within 1 week. PIPP at a 40 mL/min infusion rate appears to be safe and feasible for perfusion of the pancreas.

  20. System Design Strategies of Post-Accident Monitoring System for a PGSFR in Korea

    International Nuclear Information System (INIS)

    Jang, Gwi-sook; Jeong, Kwang-il; Keum, Jong-yong; Seong, Seung-hwan

    2013-06-01

    Monitoring systems of a PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor) in Korea provide alarms, integrity information in the reactor building, sodium-water reaction information in the steam generator, fuel failure information, and supporting information for maintenance and inspection. In particular, a Post-Accident Monitoring System (PAMS) provides primary information for operators to assess the plant conditions and perform their role in bringing the plant to a safe condition during an accident. Some PAM variables can be allocated as more two types. It is important for system designers to confirm the suitability of the selection of PAM variables. In addition, the PAMS is a position 4 display against common cause failures of safety I and C systems. The position 4 display should be independent and diverse from the safety I and C systems. The diversity of safety I and C equipment has led to an increase in the design and verification and validation cost. Thus, this paper proposes the system design strategies on the PAMS design problems of the PGSFR in KOREA. The results will be input into a conceptual system design for the PAMS of the PGSFR in KOREA. (authors)

  1. Design of an insulator leakage current measurement system based on PLC

    Science.gov (United States)

    Sun, Changhai; Wu, Yan; Han, Wenqi

    2013-03-01

    It is usually difficult to detect a small current signal in a high-pressure environment with strong electromagnetic interference. The paper introduces a high-voltage electrical equipment that is used to measure the small current. The system consists of three parts including the DC high voltage generator, data acquisition modules and PC data display section. The experimental results show that the device can acquire weak current signal effectively. Data acquisition module can communicate with the PC software with Ethernet, and the users can store, query the data through a database easily.

  2. 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)

  3. GIS-based accident location and analysis system (GIS-ALAS) : project report : phase I

    Science.gov (United States)

    1998-04-06

    This report summarizes progress made in Phase I of the geographic information system (GIS) based Accident Location and Analysis System (GIS-ALAS). The GIS-ALAS project builds on PC-ALAS, a locationally-referenced highway crash database query system d...

  4. Coupling the severe accident code SCDAP with the system thermal hydraulic code MARS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Jin; Chung, Bub Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    MARS is a best-estimate system thermal hydraulics code with multi-dimensional modeling capability. One of the aims in MARS code development is to make it a multi-functional code system with the analysis capability to cover the entire accident spectrum. For this purpose, MARS code has been coupled with a number of other specialized codes such as CONTEMPT for containment analysis, and MASTER for 3-dimensional kinetics. And in this study, the SCDAP code has been coupled with MARS to endow the MARS code system with severe accident analysis capability. With the SCDAP, MARS code system now has acquired the capability to simulate such severe accident related phenomena as cladding oxidation, melting and slumping of fuel and reactor structures.

  5. Coupling the severe accident code SCDAP with the system thermal hydraulic code MARS

    International Nuclear Information System (INIS)

    Lee, Young Jin; Chung, Bub Dong

    2004-01-01

    MARS is a best-estimate system thermal hydraulics code with multi-dimensional modeling capability. One of the aims in MARS code development is to make it a multi-functional code system with the analysis capability to cover the entire accident spectrum. For this purpose, MARS code has been coupled with a number of other specialized codes such as CONTEMPT for containment analysis, and MASTER for 3-dimensional kinetics. And in this study, the SCDAP code has been coupled with MARS to endow the MARS code system with severe accident analysis capability. With the SCDAP, MARS code system now has acquired the capability to simulate such severe accident related phenomena as cladding oxidation, melting and slumping of fuel and reactor structures

  6. Quantifying Information Leakage of Randomized Protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Wasowski, Andrzej; Legay, Axel

    2013-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model and analyze the information leakage of deterministic and probabilistic systems. We show that this method generalizes the lattice of inform...... and non-timed attacks on the Onion Routing protocol....

  7. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    International Nuclear Information System (INIS)

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies

  8. REACTOR: an expert system for diagnosis and treatment of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Nelson, W.R.

    1982-01-01

    REACTOR is an expert system under development at EG and G Idaho, Inc., that will assist operators in the diagnosis and treatment of nuclear reactor accidents. This paper covers the background of the nuclear industry and why expert system technology may prove valuable in the reactor control room. Some of the basic features of the REACTOR system are discussed, and future plans for validation and evaluation of REACTOR are presented. The concept of using both event-oriented and function-oriented strategies for accident diagnosis is discussed. The response tree concept for representing expert knowledge is also introduced

  9. Groundwater modeling to evaluate interaquifer leakage in the Floridan aquifer system near Hunter Army Airfield and Fort Stewart

    Science.gov (United States)

    Cherry, Gregory S.

    2011-01-01

    Simulations using a modified regional groundwater- flow model were used to determine the amount of leakage from the Upper Floridan aquifer (UFA) through the Lower Floridan confining unit (LFC) into the Lower Floridan aquifer (LFA) resulting from pumping about 1 million gallons per day at newly constructed LFA production wells at Hunter Army Airfield and Fort Stewart in coastal Georgia. Simulated steadystate drawdown at each of the LFA production wells closely matched observed drawdown during a 72-hour aquifer test with the observed water levels reaching steady-state by the end of the test period. However, simulated drawdown was greater than observed drawdown in the UFA because of the short duration of the aquifer test and the time required for groundwater movement through the LFC into the LFA. Steadystate simulations provide an estimate of leakage based on the long-term continuous operation of each production well. Results of model simulations indicate that interaquifer leakage accounts for 48 percent of the flow to the well at Hunter Army Airfield, and 98 percent of the flow to the well at Fort Stewart. Simulated results near the Hunter Army Airfield production well indicated that 65 percent of the leakage from the UFA to the LFA occurs within a 1-mile radius, whereas simulated results near the Fort Stewart production well indicated 80-percent leakage from the UFA to the LFA within the same radius. The greater amount of leakage to the production well near Fort Stewart can be attributed to the higher transmissivity of the UFA and higher vertical hydraulic conductivity in the LFC near the well.

  10. Early detection of LPG gas leakage based Wireless Sensor Networking

    Directory of Open Access Journals (Sweden)

    Kusriyanto Medilla

    2018-01-01

    Full Text Available LPG gas is the main fuel used in households. These days LPG gas leak triggered an accident that resulted in huge losses, especially if the accident occurred within the dense housing. LPG gas leakage monitoring and early detection of a gas leak and a leak warning is needed to prevent more fatal accident. Wireless sensor networking is a technology that can be used to build a centralized monitoring system by using a microcontroller as the interface and control system. This research developed system device monitoring and early detection of gas leaks by utilizing gas sensors MQ-4 and AVR microcontroller family as control devices. The system is also equipped with XBee PRO S2B nirkable devices as the interface to the wireless networking system that is used to transmit sensor data from the detection point to the monitoring center equipped with a PC and software integrated Visual Basic. Gas leak alert is sent with the message formats through social networking Gtalk.

  11. Low leakage mechanical joint development

    International Nuclear Information System (INIS)

    Crago, W.A.

    1976-01-01

    As a consequence of the development programs described, certain recommendatons for design of mechanial joints have been proposed. These include: 1. Spiral wound gaskets filled with chrysotile asbestos are adequate for primary heat transport system fluid conditions. 2. Spiral wound gaskets should be seated under a stress of 110 to 125 MPa for low leakage performance. 3. Load maintenance, while perhaps reducing leakage, introduces more complex hardware, and is of unproven benefit. 4. Uniform circumferential load application requires the use of hydraulic stud tensioners to ensure satisfactory performance from large size mechanical joints. (author)

  12. 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.)

  13. The system of emergency cards for primary actions in accident at radioactive material transport in Russia

    Energy Technology Data Exchange (ETDEWEB)

    Ananiev, V.V. [Div. of the Decommission of Nuclear and Radiation-Hazardous Object of the Federal Agency for Atomic Energy, Moscow (Russian Federation); Ermakov, S.V.; Ershov, V.N.; Stovbur, V.I. [FGUP ' ' Emergency Response Centre of Minatom of Russia' ' , St-Petersburg (Russian Federation); Shvedov, M.O. [Div. of Nuclear and Radiation Safety of the Federal Agency for Atomic Energy, Moscow (Russian Federation)

    2004-07-01

    In the paper are reviewed the current and new designed system of the emergency cards for consignments of radioactive materials in Russian Federation, within the framework of a uniform state system of warning and liquidation of consequences of extraordinary situations and functional subsystem of warning and liquidation of accident situations of Federal Agency for Atomic Energy.

  14. Replacement of the criticality accident alarm system in the Tokai reprocessing plant

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Momose, Takumaro; Suzuki, Kei; Kawai, Keiichi

    2008-01-01

    A Criticality Accident Alarm System (CAAS) was installed as part of criticality safety management for use in reducing the radiation workers could be exposed to in the rare case of a criticality accident. The initial CAAS version was installed the Tokai Reprocessing Plant (TRP) in the 1980s. It includes units that can detect gamma-rays or neutron-rays released in criticality accidents (CADs), one of which consists of three plastic scintillation gamma detectors and three solid state neutron detectors with fissile material, and in being highly reliable utilizes the 2 out of 3 voting system. The purpose of this study is to give the design principles and procedures for determining the adequate relocation of the CADs within the TRP. The optimal places for the CADs to be relocated to were determined using a conservative evaluation method. Firstly, equipment needing to be monitored for criticality accidents was selected with consideration given to the risk of excessive exposure to workers. Secondly, the detection threshold of a minimum accident was set to be an increase in power of 10 15 fissions/s occurring within a rise-time of between 0.5 ms and 1 s. The sum of neutron and gamma doses of a minimum accident (10 15 fissions) was 0.3 Gy at an unshielded distance of 1 m. Finally, doses at where the CADs were installed were evaluated using parameters calculated with MCNP and ANISN. As a result, the alarm trip level of both the gamma detector and the neutron detector being set at 2.0 mGy/h enabled minimum criticality accidents to be conservatively detected. These results were then applied to the new CAD positions. (author)

  15. Radiotherapy Accidents

    Science.gov (United States)

    Mckenzie, Alan

    A major benefit of a Quality Assurance system in a radiotherapy centre is that it reduces the likelihood of an accident. For over 20 years I have been the interface in the UK between the Institute of Physics and Engineering in Medicine and the media — newspapers, radio and TV — and so I have learned about radiotherapy accidents from personal experience. In some cases, these accidents did not become public and so the hospital cannot be identified. Nevertheless, lessons are still being learned.

  16. Possibility of the development of a Serbian protection system against chemical accidents

    Directory of Open Access Journals (Sweden)

    Dejan R. Inđić

    2012-10-01

    Full Text Available The paper presents a draft of a system model for responding in case of chemical accidents in accordance with the current legislation regarding the environment protection, the structure and elements of the existing response system in case of chemical accidents, other works dealing with the issue as well as the prospects planned by those responsible for the environmental protection. The paper discuss the possibilities of different institutions and agencies of the Republic of Serbia to engage in specialized methods of cooperation and protection against chemical hazards in accordance with Article X of the Convention on the Prohibition of Chemical Weapons.

  17. Multi-phase model development to assess RCIC system capabilities under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kirkland, Karen Vierow [Texas A & M Univ., College Station, TX (United States); Ross, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beeny, Bradley [Texas A & M Univ., College Station, TX (United States); Luthman, Nicholas [Texas A& M Engineering Experiment Station, College Station, TX (United States); Strater, Zachary [Texas A & M Univ., College Station, TX (United States)

    2017-12-23

    The Reactor Core Isolation Cooling (RCIC) System is a safety-related system that provides makeup water for core cooling of some Boiling Water Reactors (BWRs) with a Mark I containment. The RCIC System consists of a steam-driven Terry turbine that powers a centrifugal, multi-stage pump for providing water to the reactor pressure vessel. The Fukushima Dai-ichi accidents demonstrated that the RCIC System can play an important role under accident conditions in removing core decay heat. The unexpectedly sustained, good performance of the RCIC System in the Fukushima reactor demonstrates, firstly, that its capabilities are not well understood, and secondly, that the system has high potential for extended core cooling in accident scenarios. Better understanding and analysis tools would allow for more options to cope with a severe accident situation and to reduce the consequences. The objectives of this project were to develop physics-based models of the RCIC System, incorporate them into a multi-phase code and validate the models. This Final Technical Report details the progress throughout the project duration and the accomplishments.

  18. Applying of Reliability Techniques and Expert Systems in Management of Radioactive Accidents

    International Nuclear Information System (INIS)

    Aldaihan, S.; Alhbaib, A.; Alrushudi, S.; Karazaitri, C.

    1998-01-01

    Accidents including radioactive exposure have variety of nature and size. This makes such accidents complex situations to be handled by radiation protection agencies or any responsible authority. The situations becomes worse with introducing advanced technology with high complexity that provide operator huge information about system working on. This paper discusses the application of reliability techniques in radioactive risk management. Event tree technique from nuclear field is described as well as two other techniques from nonnuclear fields, Hazard and Operability and Quality Function Deployment. The objective is to show the importance and the applicability of these techniques in radiation risk management. Finally, Expert Systems in the field of accidents management are explored and classified upon their applications

  19. Qualitative analysis of the man-organization system in accident conditions for nuclear installations

    International Nuclear Information System (INIS)

    Farcasiu, Mita; Prisecaru, Ilie

    2010-01-01

    In this paper a model of the human performance investigation of accident conditions in the operation of the nuclear installation is developed. A framework for analyses of the human action in the man-organization system context is achieved. The goal of this model is to identify the possible roots causing human errors which could occur during the evolution of the accident by the qualitative analysis of the interfaces in man-organization system. These interfaces represent the main elements which characterize the implication of the organization in human performance. The results of this paper are the interfaces of the man-organization and their circumstances in which human performance could fail. Also, another result is a pre-designed framework which could help in the investigation of an accident. (authors)

  20. Study on integrated approach of Nuclear Accident Hazard Predicting, Warning, and Optimized Controlling System based on GIS

    International Nuclear Information System (INIS)

    Tang Lijuan; Huang Shunxiang; Wang Xinming

    2012-01-01

    The issue of nuclear safety becomes the attention focus of international society after the nuclear accident happened in Fukushima. Aiming at the requirements of the prevention and controlling of Nuclear Accident establishment of Nuclear Accident Hazard Predicting, Warning and optimized Controlling System (NAPWS) is a imperative project that our country and army are desiderating, which includes multiple fields of subject as nuclear physics, atmospheric science, security science, computer science and geographical information technology, etc. Multiplatform, multi-system and multi-mode are integrated effectively based on GIS, accordingly the Predicting, Warning, and Optimized Controlling technology System of Nuclear Accident Hazard is established. (authors)

  1. Developing a Minimum Data Set for an Information Management System to Study Traffic Accidents in Iran.

    Science.gov (United States)

    Mohammadi, Ali; Ahmadi, Maryam; Gharagozlu, Alireza

    2016-03-01

    Each year, around 1.2 million people die in the road traffic incidents. Reducing traffic accidents requires an exact understanding of the risk factors associated with traffic patterns and behaviors. Properly analyzing these factors calls for a comprehensive system for collecting and processing accident data. The aim of this study was to develop a minimum data set (MDS) for an information management system to study traffic accidents in Iran. This descriptive, cross-sectional study was performed in 2014. Data were collected from the traffic police, trauma centers, medical emergency centers, and via the internet. The investigated resources for this study were forms, databases, and documents retrieved from the internet. Forms and databases were identical, and one sample of each was evaluated. The related internet-sourced data were evaluated in their entirety. Data were collected using three checklists. In order to arrive at a consensus about the data elements, the decision Delphi technique was applied using questionnaires. The content validity and reliability of the questionnaires were assessed by experts' opinions and the test-retest method, respectively. An (MDS) of a traffic accident information management system was assigned to three sections: a minimum data set for traffic police with six classes, including 118 data elements; a trauma center with five data classes, including 57 data elements; and a medical emergency center, with 11 classes, including 64 data elements. Planning for the prevention of traffic accidents requires standardized data. As the foundation for crash prevention efforts, existing standard data infrastructures present policymakers and government officials with a great opportunity to strengthen and integrate existing accident information systems to better track road traffic injuries and fatalities.

  2. Risk Analysis on Leakage Failure of Natural Gas Pipelines by Fuzzy Bayesian Network with a Bow-Tie Model

    Directory of Open Access Journals (Sweden)

    Xian Shan

    2017-01-01

    Full Text Available Pipeline is the major mode of natural gas transportation. Leakage of natural gas pipelines may cause explosions and fires, resulting in casualties, environmental damage, and material loss. Efficient risk analysis is of great significance for preventing and mitigating such potential accidents. The objective of this study is to present a practical risk assessment method based on Bow-tie model and Bayesian network for risk analysis of natural gas pipeline leakage. Firstly, identify the potential risk factors and consequences of the failure. Then construct the Bow-tie model, use the quantitative analysis of Bayesian network to find the weak links in the system, and make a prediction of the control measures to reduce the rate of the accident. In order to deal with the uncertainty existing in the determination of the probability of basic events, fuzzy logic method is used. Results of a case study show that the most likely causes of natural gas pipeline leakage occurrence are parties ignore signage, implicit signage, overload, and design defect of auxiliaries. Once the leakage occurs, it is most likely to result in fire and explosion. Corresponding measures taken on time will reduce the disaster degree of accidents to the least extent.

  3. Assuring asset integrity through improving the accuracy of leakage source identification of a permanently installed subsea leak detection system using artificial neural networks

    OpenAIRE

    Poungkrajorn, Tawan

    2015-01-01

    Master's thesis in Offshore technology : industrial asset management Environmental concerns and regulatory controls for oil and gas exploration and production activities have been increasing with the prospecting of deep-water fields and sensitive areas, such as the artic seas. To stop any incidents developing into critical events, subsea leak detection systems are required for a fast, cost-effective, and reasonable accurate method to not only detect the leakage substance (in this case meth...

  4. Accident precursors, near misses, and warning signs: Critical review and formal definitions within the framework of Discrete Event Systems

    International Nuclear Information System (INIS)

    Saleh, Joseph H.; Saltmarsh, Elizabeth A.; Favarò, Francesca M.; Brevault, Loïc

    2013-01-01

    An important consideration in safety analysis and accident prevention is the identification of and response to accident precursors. These off-nominal events are opportunities to recognize potential accident pathogens, identify overlooked accident sequences, and make technical and organizational decisions to address them before further escalation can occur. When handled properly, the identification of precursors provides an opportunity to interrupt an accident sequence from unfolding; when ignored or missed, precursors may only provide tragic proof after the fact that an accident was preventable. In this work, we first provide a critical review of the concept of precursor, and we highlight important features that ought to be distinguished whenever accident precursors are discussed. We address for example the notion of ex-ante and ex-post precursors, identified for postulated and instantiated (occurred) accident sequences respectively, and we discuss the feature of transferability of precursors. We then develop a formal (mathematical) definition of accident precursors as truncated accident sequences within the modeling framework of Discrete Event Systems. Additionally, we examine the related notions of “accident pathogens” as static or lurking adverse conditions that can contribute to or aggravate an accident, as well as “near misses”, “warning signs” and the novel concept of “accident pathway”. While these terms are within the same linguistic neighborhood as “accident precursors”, we argue that there are subtle but important differences between them and recommend that they not be used interchangeably for the sake of accuracy and clarity of communication within the risk and safety community. We also propose venues for developing quantitative importance measures for accident precursors, similar to component importance measures in reliability engineering. Our objective is to establish a common understanding and clear delineation of these terms, and

  5. Land-use Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Katherine V.; Edmonds, James A.; Clarke, Leon E.; Bond-Lamberty, Benjamin; Kim, Son H.; Wise, Marshall A.; Thomson, Allison M.; Kyle, G. Page

    2009-12-01

    Leakage occurs whenever actions to mitigate greenhouse gas emissions in one part of the world unleash countervailing forces elsewhere in the world so that reductions in global emissions are less than emissions mitigation in the mitigating region. While many researchers have examined the concept of industrial leakage, land-use policies can also result in leakage. We show that land-use leakage is potentially as large as or larger than industrial leakage. We identify two potential land-use leakage drivers, land-use policies and bioenergy. We distinguish between these two pathways and run numerical experiments for each. We also show that the land-use policy environment exerts a powerful influence on leakage and that under some policy designs leakage can be negative. International “offsets” are a potential mechanism to communicate emissions mitigation beyond the borders of emissions mitigating regions, but in a stabilization regime designed to limit radiative forcing to 3.7 2/m2, this also implies greater emissions mitigation commitments on the part of mitigating regions.

  6. Model for Electromagnetic Information Leakage

    OpenAIRE

    Mao Jian; Li Yongmei; Zhang Jiemin; Liu Jinming

    2013-01-01

    Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and ana...

  7. Hydrogen-control systems for severe LWR accident conditions - a state-of-technology report

    Energy Technology Data Exchange (ETDEWEB)

    Hilliard, R K; Postma, A K; Jeppson, D W

    1983-03-01

    This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report relate to control systems and include combustion prevention, controlled combustion, minimization of combustion effects, combination of control concepts, and post-accident disposal. A companion report addresses hydrogen generation, distribution, and combustion. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues.

  8. Extra-regulatory accident safety evaluation for the PWR S/F transport and storage system

    International Nuclear Information System (INIS)

    Seo, K. S.; Lee, J. C.; Bang, K. S.; Choi, W. S.; Lee, S. H.; Seo, J. S.; Kim, K. Y.; Jeon, J. E.

    2011-06-01

    In the field of high speed crash, high speed impact analyses and test were performed for two systems, the dual purpose metal cask and the concrete cask considering the aircraft crash condition. Through the tests, the procedure and methodology of the assessment were successfully validated. In the field of transient fire, the computer simulation method for transient fire was drawn through the overseas status and methodology analysis. In the field of cumulative damage evaluation for transport accident, the analysis technique for assessment for cumulative damages which occurred from successive accident conditions was developed and proposed. And the sequential tests for the dual purpose cask were performed

  9. Hydrogen-control systems for severe LWR accident conditions - a state-of-technology report

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Postma, A.K.; Jeppson, D.W.

    1983-03-01

    This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report relate to control systems and include combustion prevention, controlled combustion, minimization of combustion effects, combination of control concepts, and post-accident disposal. A companion report addresses hydrogen generation, distribution, and combustion. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues

  10. Fuel relocation modeling in the SAS4A accident analysis code system

    International Nuclear Information System (INIS)

    Tentner, A.M.; Miles, K.J.; Kalimullah; Hill, D.J.

    1986-01-01

    The SAS4A code system has been designed for the analysis of the initial phase of Hypothetical Core Disruptive Accidents (HCDAs) up to gross melting or failure of the subassembly walls. During such postulated accident scenarios as the Loss-of-Flow (LOF) and Transient-Overpower (TOP) events, the relocation of the fuel plays a key role in determining the sequence of events and the amount of energy produced before neutronic shutdown. This paper discusses the general strategy used in modelong the various phenomena which lead to fuel relocation and presents the key fuel relocation models used in SAS4A. The implications of these models for the whole-core accident analysis as well as recent results of fuel relocation are emphasized. 12 refs

  11. [Injuries caused by traffic accidents: passive safety and restraint systems in automobiles].

    Science.gov (United States)

    Zuppichini, F; Orlandi, E; Genna, M; Rodella, L; Ricci, G; Arienzo, A; Dorrucci, V; Inaspettato, G

    1986-10-01

    In this article are considered the multiple instruments today employed in cars, in order to prevent or ameliorate the lesions caused to the occupants in case of road accident. The acquisitions in the differentiated structure of the car, in the windshield, in the components of the passenger cell are described, and the peculiar importance of the restraint systems is evidenced.

  12. Full scale simulations of accidents on spent-nuclear-fuel shipping systems

    International Nuclear Information System (INIS)

    Yoshimura, H.R.

    1978-01-01

    In 1977 and 1978, five first-of-a-kind full scale tests of spent-nuclear-fuel shipping systems were conducted at Sandia Laboratories. The objectives of this broad test program were (1) to assess and demonstrate the validity of current analytical and scale modeling techniques for predicting damage in accident conditions by comparing predicted results with actual test results, and (2) to gain quantitative knowledge of extreme accident environments by assessing the response of full scale hardware under actual test conditions. The tests were not intended to validate the present regulatory standards. The spent fuel cask tests fell into the following configurations: crashes of a truck-transport system into a massive concrete barrier (100 and 130 km/h); a grade crossing impact test (130 km/h) involving a locomotive and a stalled tractor-trailer; and a railcar shipping system impact into a massive concrete barrier (130 km/h) followed by fire. In addition to collecting much data on the response of cask transport systems, the program has demonstrated thus far that current analytical and scale modeling techniques are valid approaches for predicting vehicular and cask damage in accident environments. The tests have also shown that the spent casks tested are extremely rugged devices capable of retaining their radioactive contents in very severe accidents

  13. Application research of cloud computing in emergency system platform of nuclear accidents

    International Nuclear Information System (INIS)

    Zhang Yan; Yue Huiguo; Lin Quanyi; Yue Feng

    2013-01-01

    This paper described the key technology of the concept of cloud computing, service type and implementation methods. Combined with the upgrade demand of nuclear accident emergency system platform, the paper also proposed the application design of private cloud computing platform, analyzed safety of cloud platform and the characteristics of cloud disaster recovery. (authors)

  14. Development of passive condensers for accident localization systems at nuclear power plants in the former USSR

    International Nuclear Information System (INIS)

    Kuznecov, M.V.

    1992-01-01

    The development is summarized of passive condensers for accident localization systems at nuclear power plants (with RBMK and WWER reactors) in the former USSR. Basic properties and criteria defining their availability are described, as are experimental tests and technical solution optimization results. (author) 2 fig

  15. Investigation into the causes of accidents on scraper systems in the gold and platinum mining sectors

    CSIR Research Space (South Africa)

    Moseme, R

    2003-11-01

    Full Text Available Advisory Committee Project Summary : Project Title: Investigation into causes of accidents on scraper systems in the Gold and Platinum mining sectors Author(s): R. Moseme, S.M. Rupprecht, P.J. Foster and R.L. Demana Agency: CSIR...

  16. Environmental decision support system on base of geoinformational technologies for the analysis of nuclear accident consequences

    International Nuclear Information System (INIS)

    Haas, T.C.; Maigan, M.; Arutyunyan, R.V.; Bolshov, L.A.; Demianov, V.V.

    1996-01-01

    The report deals with description of the concept and prototype of environmental decision support system (EDSS) for the analysis of late off-site consequences of severe nuclear accidents and analysis, processing and presentation of spatially distributed radioecological data. General description of the available software, use of modem achievements of geostatistics and stochastic simulations for the analysis of spatial data are presented and discussed

  17. Characteristics of Hydrogen Monitoring Systems for Severe Accident Management at a Nuclear Power Plant

    Science.gov (United States)

    Petrosyan, V. G.; Yeghoyan, E. A.; Grigoryan, A. D.; Petrosyan, A. P.; Movsisyan, M. R.

    2018-02-01

    One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems' requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase

  18. Acoustic control of sodium leakage in valve gates of NPP

    International Nuclear Information System (INIS)

    Trykov, E.L.; Kovtun, S.N.; Anan'ev, A.A.; Yugov, S.I.

    2014-01-01

    Short description of sodium bench and acoustic investigation results on leakage monitoring of valves DN10 and DN40 are given. It is shown that acoustic method can be used successfully to control the leakages of sodium valves. Leakages on both type of valves increase the acoustic signal dispersion by 2-3 orders. For each type of valve acoustic system of leakage determination allows to conduct the preliminary graduation of signal dispersion on the sodium discharge rate. It make possible not only to record the leakage presence but also to determine the sodium discharge rate through the valve during the leakage [ru

  19. An expert system for the quantification of fault rates in construction fall accidents.

    Science.gov (United States)

    Talat Birgonul, M; Dikmen, Irem; Budayan, Cenk; Demirel, Tuncay

    2016-01-01

    Expert witness reports, prepared with the aim of quantifying fault rates among parties, play an important role in a court's final decision. However, conflicting fault rates assigned by different expert witness boards lead to iterative objections raised by the related parties. This unfavorable situation mainly originates due to the subjectivity of expert judgments and unavailability of objective information about the causes of accidents. As a solution to this shortcoming, an expert system based on a rule-based system was developed for the quantification of fault rates in construction fall accidents. The aim of developing DsSafe is decreasing the subjectivity inherent in expert witness reports. Eighty-four inspection reports prepared by the official and authorized inspectors were examined and root causes of construction fall accidents in Turkey were identified. Using this information, an evaluation form was designed and submitted to the experts. Experts were asked to evaluate the importance level of the factors that govern fall accidents and determine the fault rates under different scenarios. Based on expert judgments, a rule-based expert system was developed. The accuracy and reliability of DsSafe were tested with real data as obtained from finalized court cases. DsSafe gives satisfactory results.

  20. Comparison of preparation design and material thickness on microbial leakage through Cavit using a tooth model system.

    Science.gov (United States)

    Weston, Charles H; Barfield, Robert D; Ruby, John D; Litaker, Mark S; McNeal, Sandre F; Eleazer, Paul D

    2008-04-01

    Few studies have compared Cavit thickness and access design as factors in microbial leakage. The present study used an acrylic tooth model to measure leakage of Streptococcus mutans. Pilot studies confirming the sterility of Cavit showed it will inhibit microbial growth for 2 days. The experiments compared class I preparations where Cavit thickness was 4 mm with class II preparations where thickness was 2-3 mm. Accesses sealed with cotton pellets were compared with those without cotton. Results of the study showed no bacterial contamination in any of the class I samples (up to 14 days). Some class II samples showed contamination at day 1 (3 out of 14), with all contaminated at day 7 (14 of 14), yet only 1 contaminated at day 14 (1 out of 14). The results suggest that a 4-mm thickness of Cavit should prevent bacterial ingress for at least 2 weeks, but microbial leakage may occur if temporary thickness is less than 3 mm or in a complex access preparation.

  1. Large Break LOCA Accident Management Strategies for Accidents With Large Containment Leaks

    International Nuclear Information System (INIS)

    Sdouz, Gert

    2006-01-01

    The goal of this work is the investigation of the influence of different accident management strategies on the thermal-hydraulics in the containment during a Large Break Loss of Coolant Accident with a large containment leak from the beginning of the accident. The increasing relevance of terrorism suggests a closer look at this kind of severe accidents. Normally the course of severe accidents and their associated phenomena are investigated with the assumption of an intact containment from the beginning of the accident. This intact containment has the ability to retain a large part of the radioactive inventory. In these cases there is only a release via a very small leakage due to the un-tightness of the containment up to cavity bottom melt through. This paper represents the last part of a comprehensive study on the influence of accident management strategies on the source term of VVER-1000 reactors. Basically two different accident sequences were investigated: the 'Station Blackout'- sequence and the 'Large Break LOCA'. In a first step the source term calculations were performed assuming an intact containment from the beginning of the accident and no accident management action. In a further step the influence of different accident management strategies was studied. The last part of the project was a repetition of the calculations with the assumption of a damaged containment from the beginning of the accident. This paper concentrates on the last step in the case of a Large Break LOCA. To be able to compare the results with calculations performed years ago the calculations were performed using the Source Term Code Package (STCP), hydrogen explosions are not considered. In this study four different scenarios have been investigated. The main parameter was the switch on time of the spray systems. One of the results is the influence of different accident management strategies on the source term. In the comparison with the sequence with intact containment it was

  2. Analysis of accidental loss of pool coolant due to leakage in a PWR SFP

    International Nuclear Information System (INIS)

    Wu, Xiaoli; Li, Wei; Zhang, Yapei; Tian, Wenxi; Su, Guanghui; Qiu, Suizheng

    2015-01-01

    Highlights: • Accidental loss of pool coolant due to leakage in a PWR SFP was studied using MAAP5. • The effect of emergency ventilation on the accident progression was investigated. • The effect of emergency injection on the accident progression was discussed. - Abstract: A large loss of pool coolant/water accident may be caused by extreme accidents such as the pool wall or bottom floor punctures due to a large aircraft strike. The safety of SFP under this circumstance is very important. Large amounts of radioactive materials would be easily released into the environment if a severe accident happened in the SFP, because the spent fuel pool (SFP) in a PWR nuclear power station (NPS) is often located in the fuel handing building outside the reactor containment. To gain insight into the loss of pool coolant accident progression for a pressurized water reactor (PWR) SFP, a computational model was established by using the Modular Accident Analysis Program (MAAP5). Important factors such as Zr oxidation by air, air natural circulation and thermal radiation were considered for partial and complete drainage accidents without mitigation measures. The calculation indicated that even if the residual water level was in the active fuel region, there was a chance to effectively remove the decay heat through axial heat conduction (if the pool cooling system failed) or steam cooling (if the pool cooling system was working). For sensitivity study, the effects of emergency ventilation and water injection on the accident progression were analyzed. The analysis showed that for the current configuration of high-density storage racks, it was difficult to cool the spent fuels by air natural circulation. Enlarging the space between the adjacent assemblies was a way of increasing air natural circulation flow rate and maintaining the coolability of SFP. Water injection to the bottom of the SFP helped to recover water inventory, quenching the high temperature assemblies to prevent

  3. Radiofrequency radiation leakage from microwave ovens

    International Nuclear Information System (INIS)

    Lahham, A.; Sharabati, A.

    2013-01-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm -1 with an average value equalling 3.64 μW cm -2 . Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm -2 . The highest radiation leakage from any tested oven was ∼16.4 μW cm -2 , and found in two cases only. In no case did the leakage exceed the limit of 1 μWcm -1 recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age. (authors)

  4. The intelligent system for accident identification in nuclear power plant

    International Nuclear Information System (INIS)

    Hernandez, Jorge Luis.

    1998-01-01

    Accidental situations in NPP are of greet concern for operators, the facility, regulatory bodies and the environment. This work proposes a design of intelligent system aimed to assist the operator in the process of decision making when initiator events with higher relative contribution to the reactor core damage occur. The intelligent System uses the results of the pre operational Probabilistic Safety Assessment and the Thermal hydraulic Safety Analyses of the NPP Juragua as source for building its knowledge base. The nucleus of the system is presented as a design of an intelligent hybrid system from the combination of the artificial intelligence techniques: fussy logic and artificial neural networks. The system works with variables from the process of the firsts circuit, second circuit and the containment and it is presented as a model for the integration of safety analyses in the process of decision making by the operator when tackling with accidental situations

  5. The intelligent system for accident identification in NPP

    International Nuclear Information System (INIS)

    Hernandez, Jorge Luis.

    1998-01-01

    Accidental situations in NPP are of greet concern for operators, the facility, regulatory bodies and the environment. This work proposes a design of intelligent system aimed to assist the operator in the process of decision making when initiator events with higher relative contribution to the reactor core damage occur. The intelligent System uses the results of the pre operational Probabilistic Safety Assessment and the Thermal hydraulic Safety Analyses of the NPP Juragua as source for building its knowledge base. The nucleus of the system is presented as a design of an intelligent hybrid system from the combination of the artificial intelligence techniques: fussy logic and artificial neural networks. The system works with variables from the process of the firsts circuit, second circuit and the containment and it is presented as a model for the integration of safety analyses in the process of decision making by the operator when tackling with accidental situations

  6. Accidental Bowel Leakage

    Science.gov (United States)

    ... nerve stimulation, injections, and surgery. What types of lifestyle changes can help treat accidental bowel leakage? Having ... Journal Clinical Updates Practice Management Coding Health Info Technology Professional Liability Managing Your Practice Patient Safety & Quality ...

  7. Response of the SPND measurement system to temperature during the Three Mile Island Unit 2 accident

    International Nuclear Information System (INIS)

    Wilde, N.; Morrison, J.L. Jr.

    1981-12-01

    The Self-Powered Neutron Detector (SPND) Measuring System is evaluated to determine its ability to indicate temperatures of the fuel rods in the TMI-2 reactor core during the accident. It is concluded for the following reasons that the SPND Measuring System did not provide fuel rod temperatures during the accident: the heat transfer characteristics vary over a range of five octaves; within the range of 1200 to 1800 0 F, the SPND responds to temperature from convection radiation from the fuel rods and self-heating from the gamma flux; within the range of 1200 to 1800 0 F, the signal cable introduces masking signals that are a function of gamma heating, integrated temperature over the cable, and core water level velocity; the data system's worst-case signal-to-noise ratio from aliasing is 0dB; and the recorder system's worst-case signal-to-noise ratio from aliasing is -24dB

  8. Accident tolerant high-pressure helium injection system concept for light water reactors

    International Nuclear Information System (INIS)

    Massey, Caleb; Miller, James; Vasudevamurthy, Gokul

    2016-01-01

    Highlights: • Potential helium injection strategy is proposed for LWR accident scenarios. • Multiple injection sites are proposed for current LWR designs. • Proof-of-concept experimentation illustrates potential helium injection benefits. • Computational studies show an increase in pressure vessel blowdown time. • Current LOCA codes have the capability to include helium for feasibility calculations. - Abstract: While the design of advanced accident-tolerant fuels and structural materials continues to remain the primary focus of much research and development pertaining to the integrity of nuclear systems, there is a need for a more immediate, simple, and practical improvement in the severe accident response of current emergency core cooling systems. Current blowdown and reflood methodologies under accident conditions still allow peak cladding temperatures to approach design limits and detrimentally affect the integrity of core components. A high-pressure helium injection concept is presented to enhance accident tolerance by increasing operator response time while maintaining lower peak cladding temperatures under design basis and beyond design basis scenarios. Multiple injection sites are proposed that can be adapted to current light water reactor designs to minimize the need for new infrastructure, and concept feasibility has been investigated through a combination of proof-of-concept experimentation and computational modeling. Proof-of-concept experiments show promising cooling potential using a high-pressure helium injection concept, while the developed choked-flow model shows core depressurization changes with added helium injection. Though the high-pressure helium injection concept shows promise, future research into the evaluation of system feasibility and economics are needed.Classification: L. Safety and risk analysis

  9. Experience with neutron flux monitoring systems qualified for post-accident monitoring

    International Nuclear Information System (INIS)

    Shugars, H.G.; Miller, J.F.

    1995-01-01

    In this paper we discuss the environmental requirements for excore neutron flux monitors that are qualified for use during and after postulated accidents in Pressurized Water Reactors (PWRs). We emphasize PWRs designed in the United States, which are similar to those used also in parts of Western Europe and Eastern Asia. We then discuss design features of the flux monitoring systems necessary to address the environmental, functional, and regulatory requirements, and the experience with these systems. (author). 9 refs, 2 figs

  10. Accident diagnosis system based on real-time decision tree expert system

    Science.gov (United States)

    Nicolau, Andressa dos S.; Augusto, João P. da S. C.; Schirru, Roberto

    2017-06-01

    Safety is one of the most studied topics when referring to power stations. For that reason, sensors and alarms develop an important role in environmental and human protection. When abnormal event happens, it triggers a chain of alarms that must be, somehow, checked by the control room operators. In this case, diagnosis support system can help operators to accurately identify the possible root-cause of the problem in short time. In this article, we present a computational model of a generic diagnose support system based on artificial intelligence, that was applied on the dataset of two real power stations: Angra1 Nuclear Power Plant and Santo Antônio Hydroelectric Plant. The proposed system processes all the information logged in the sequence of events before a shutdown signal using the expert's knowledge inputted into an expert system indicating the chain of events, from the shutdown signal to its root-cause. The results of both applications showed that the support system is a potential tool to help the control room operators identify abnormal events, as accidents and consequently increase the safety.

  11. Postulated accident conditions for air cleaning systems and radiological dose assessments for containment options

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Postma, A.K.

    1975-01-01

    Ambient conditions and performance requirements for emergency air cleaning systems applicable to commercial LMFBR plants were studied. The focus of this study centered on aerosol removal under hypothetical core disruptive accident conditions. Effort completed includes a review of air cleaning systems related to LMFBR plants, selection of three reference containment system designs, postulation of the EACS design basis accident (EACS-DBA), analysis of thermal conditions resulting from the DBA, analysis of aerosol transport behavior following the DBA, and an estimate of bone dose at the site boundary for each of the reference plant designs. Reference plant concepts were a single containment system (e.g., FFTF), a double containment system (e.g., CRBRP with closed head compartment), and a containment-confinement design in which an inerted, sealed primary volume was located within a ventilated building whose exhaust was filtered. The reference design basis accident selected here involved release to the inner containment system of 1 percent of non-volatile solids and plutonium, 25 percent of core halogens, 25 percent of core volatile solids, 100 percent of core noble gases, 68 lbs of sodium vapor and 5000 lbs of liquid sodium. 13 references. (U.S.)

  12. Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach.

    Science.gov (United States)

    Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

    2017-06-01

    Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach's alpha of 75%. Data was analyzed using the decision Delphi technique. GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information.

  13. ACCIDENT ANALYSES & CONTROL OPTIONS IN SUPPORT OF THE SLUDGE WATER SYSTEM SAFETY ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    WILLIAMS, J.C.

    2003-11-15

    This report documents the accident analyses and nuclear safety control options for use in Revision 7 of HNF-SD-WM-SAR-062, ''K Basins Safety Analysis Report'' and Revision 4 of HNF-SD-SNF-TSR-001, ''Technical Safety Requirements - 100 KE and 100 KW Fuel Storage Basins''. These documents will define the authorization basis for Sludge Water System (SWS) operations. This report follows the guidance of DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports'', for calculating onsite and offsite consequences. The accident analysis summary is shown in Table ES-1 below. While this document describes and discusses potential control options to either mitigate or prevent the accidents discussed herein, it should be made clear that the final control selection for any accident is determined and presented in HNF-SD-WM-SAR-062.

  14. Reactivity Accidents in CAREM-25 Core with and Without Safety Systems Actuation

    International Nuclear Information System (INIS)

    Gimenez, Marcelo; Vertullo, Alicia; Schlamp, Miguel

    2000-01-01

    A reactivity accident in CAREM core can be provoked by different initiating events, a cold water injection in pressure vessel, a secondary side steam line breakage and a failure in the absorbing rods drive system.The present work analyses inadverted control rod withdraws transients.Maximum worth control rod (2.5 $) at normal velocity (1 cm/s) is adopted for the simulations (Reactivity ramp of 0.018 $/s).Different scenarios considering actuation of first shutdown system (FSS), second shutdown system (SSS) and selflimiting conditions were modeled.Results of the accident with actuation of FSS show that safety margins are well above critical values (DNBR and CPR).In the cases with failure of the FSS and success of SSS or selflimited, safety margins are below critical values, however, the SSS provides a reduction of elapsed time under advised margins

  15. Safety study on nuclear heat utilization system - accident delineation and assessment on nuclear steelmaking pilot plant

    International Nuclear Information System (INIS)

    Yoshida, T.; Mizuno, M.; Tsuruoka, K.

    1982-01-01

    This paper presents accident delineation and assessment on a nuclear steelmaking pilot plant as an example of nuclear heat utilization systems. The reactor thermal energy from VHTR is transported to externally located chemical process plant employing helium-heated steam reformer by an intermediate heat transport loop. This paper on the nuclear steelmaking pilot plant will describe (1) system transients under accident conditions, (2) impact of explosion and fire on the nuclear reactor and the public and (3) radiation exposure on the public. The results presented in this paper will contribute considerably to understanding safety features of nuclear heat utilization system that employs the intermediate heat transport loop and the helium-heated steam reformer

  16. Integral isolation valve systems for loss of coolant accident protection

    Energy Technology Data Exchange (ETDEWEB)

    Kanuch, David J.; DiFilipo, Paul P.

    2018-03-20

    A nuclear reactor includes a nuclear reactor core comprising fissile material disposed in a reactor pressure vessel having vessel penetrations that exclusively carry flow into the nuclear reactor and at least one vessel penetration that carries flow out of the nuclear reactor. An integral isolation valve (IIV) system includes passive IIVs each comprising a check valve built into a forged flange and not including an actuator, and one or more active IIVs each comprising an active valve built into a forged flange and including an actuator. Each vessel penetration exclusively carrying flow into the nuclear reactor is protected by a passive IIV whose forged flange is directly connected to the vessel penetration. Each vessel penetration carrying flow out of the nuclear reactor is protected by an active IIV whose forged flange is directly connected to the vessel penetration. Each active valve may be a normally closed valve.

  17. Remotely Piloted Aircraft Systems and a Wireless Sensors Network for Radiological Accidents

    Directory of Open Access Journals (Sweden)

    A. Reyes-Muñoz

    2016-01-01

    Full Text Available In critical radiological situations, the real time information that we could get from the disaster area becomes of great importance. However, communication systems could be affected after a radiological accident. The proposed network in this research consists of distributed sensors in charge of collecting radiological data and ground vehicles that are sent to the nuclear plant at the moment of the accident to sense environmental and radiological information. Afterwards, data would be analyzed in the control center. Collected data by sensors and ground vehicles would be delivered to a control center using Remotely Piloted Aircraft Systems (RPAS as a message carrier. We analyze the pairwise contacts, as well as visiting times, data collection, capacity of the links, size of the transmission window of the sensors, and so forth. All this calculus was made analytically and compared via network simulations.

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

    International Nuclear Information System (INIS)

    Heams, T.J.; Williams, D.A.; Johns, N.A.; Mason, A.; Bixler, N.E.; Grimley, A.J.; Wheatley, C.J.; Dickson, L.W.; Osborn-Lee, I.; Domagala, P.; Zawadzki, S.; Rest, J.; Alexander, C.A.; Lee, R.Y.

    1992-12-01

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

  19. Bulgarian Emergency Response System (BERS) in case of nuclear accident with exposure doses estimation

    Energy Technology Data Exchange (ETDEWEB)

    Syrakov, D.; Prodanova, M.; Slavov, K.; Veleva, B.

    2015-07-01

    A PC-oriented Emergency Response System in case of nuclear accident (BERS) is developed and works operationally in the National Institute of Meteorology and Hydrology (NIMH). The creation and development of BERS was highly stimulated by the ETEX (European Tracer Experiment) project. BERS comprises two main parts - the operational and the accidental ones. The operational part, run automatically every 12 hours, prepares the input meteorological file used by both trajectory and dispersion models, runs the trajectory models, visualizes the results and uploads the maps of trajectories to a dedicated web-site. The accidental part is activated manually when a real radioactive releases occur or during emergency exercises. Its core is the Bulgarian dispersion models EMAP. Outputs are concentration, accumulated deposition and selected doses fields. In the paper, the BERS overall structure is described and examples of its products are presented. Key words: nuclear accident, emergency response, early warning system, air dispersion models, radioactive exposure dose. (Author)

  20. Environmental impact of accidents involving radioactive material shipping systems

    International Nuclear Information System (INIS)

    Yoshimura, H.R.; Pope, R.B.; Huerta, M.; Nilson, R.H.

    1978-01-01

    Four full-scale spent fuel cask crash tests have been performed, including two head-on truck-barrier impacts (100 and 135 km/h), one railcar-barrier impact (130 km/h), and one locomotive grade crossing impact (130 km/h). Releases to the environment were limited to seepage of about 100 cc of cavity liquid from the cask head in the 135 km/h truck impact test and a slight head seal air leak in the 130 km/h locomotive grade crossing test. These releases were well within the limits specified by the NRC regulations, would have been easily cleaned up, and would have caused little effect on the environment and virtually no risk to the public. To further evaluate cask capability, the crashed spent-fuel rail cask system was fire tested. The cask withstood 90 minutes of a fully engulfing hydrocarbon pool fire while maintaining its structural integrity. At approximately 100 minutes into the fire test, the outer shell of the cask cracked resulting in the partial loss of lead radiation shielding. The failure of the shell was attributed to poor quality control during the original fabrication of the cask in the early 1960's. Present regulatory standards would prevent such occurrences in casks built and licensed today. In addition, the test was much more severe than the qualification criteria specified by present licensing requirements. 4 tables, 13 figures

  1. A criticism of ANSI/ANS-8.3-1986: Criticality accident alarm system

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1991-01-01

    The American National Standard on criticality accident alarm systems has given rise to confusion in interpretation and implementation of the requirements. In addition, some of the standards have recently been incorporated into US Department of Energy (DOE) orders, and others have been paraphrased in the DOE orders. Some of the DOE orders referencing these standards are being incorporated into law by means of the Code of Federal Regulations. As such, the intent of the authors of the standards to recommend a code of good practice is now being codified into law with attendant civil and criminal penalties for failure to comply. It is suggested that ANSI/ANS-8.3-1986, Critically Accident Alarm System, be carefully reviewed to alleviate the confusion that has been experienced in practice, to clarify the minimum accident of concern, to further define the dose (or dose rate) criteria for activation, and to stress the fact that a prime consideration in any safety system is the overall reduction of risk

  2. Accident identification system with automatic detection of abnormal condition using quantum computation

    Energy Technology Data Exchange (ETDEWEB)

    Nicolau, Andressa dos Santos; Schirru, Roberto, E-mail: andressa@lmp.ufrj.br, E-mail: schirru@lmp.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Alan Miranda Monteiro de [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Transient identification systems have been proposed in order to maintain the plant operating in safe conditions and help operators in make decisions in emergency short time interval with maximum certainty associated. This article presents a system, time independent and without the use of an event that can be used as a starting point for t = 0 (reactor scram, for instance), for transient/accident identification of a pressurized water nuclear reactor (PWR). The model was developed in order to be able to recognize the normal condition and three accidents of the design basis list of the Nuclear Power Plant Angra 2, postulated in the Final Safety Analysis Report (FSAR). Were used several sets of process variables in order to establish a minimum set of variables considered necessary and sufficient. The optimization step of the identification algorithm is based upon the paradigm of Quantum Computing. In this case, the optimization metaheuristic Quantum Inspired Evolutionary Algorithm (QEA) was implemented and works as a data mining tool. The results obtained with the QEA without the time variable are compatible to the techniques in the reference literature, for the transient identification problem, with less computational effort (number of evaluations). This system allows a solution that approximates the ideal solution, the Voronoi Vectors with only one partition for the classes of accidents with robustness. (author)

  3. Accident identification system with automatic detection of abnormal condition using quantum computation

    International Nuclear Information System (INIS)

    Nicolau, Andressa dos Santos; Schirru, Roberto; Lima, Alan Miranda Monteiro de

    2011-01-01

    Transient identification systems have been proposed in order to maintain the plant operating in safe conditions and help operators in make decisions in emergency short time interval with maximum certainty associated. This article presents a system, time independent and without the use of an event that can be used as a starting point for t = 0 (reactor scram, for instance), for transient/accident identification of a pressurized water nuclear reactor (PWR). The model was developed in order to be able to recognize the normal condition and three accidents of the design basis list of the Nuclear Power Plant Angra 2, postulated in the Final Safety Analysis Report (FSAR). Were used several sets of process variables in order to establish a minimum set of variables considered necessary and sufficient. The optimization step of the identification algorithm is based upon the paradigm of Quantum Computing. In this case, the optimization metaheuristic Quantum Inspired Evolutionary Algorithm (QEA) was implemented and works as a data mining tool. The results obtained with the QEA without the time variable are compatible to the techniques in the reference literature, for the transient identification problem, with less computational effort (number of evaluations). This system allows a solution that approximates the ideal solution, the Voronoi Vectors with only one partition for the classes of accidents with robustness. (author)

  4. Design considerations for post accident monitoring system of a research reactor

    International Nuclear Information System (INIS)

    Jang, Gwi Sook; Park, Je Yun; Kim, Young Ki

    2012-01-01

    The Post Accident Monitoring System (PAMS) provides primary information for operators to assess the plant conditions and perform their role in bringing the plant to a safe condition during an accident. The PAMS of NPP (Nuclear Power Plant) in KOREA provides the continuous display of the PAM category 1 parameters specified in R.G 1.97, Rev. 03. Recently the PAMS of NPP has been designed according to R.G 1.97, Rev. 04. There is no PAMS at the HANARO in KOREA, but recently RRs (Research Reactors) around the world are going to have PAMS for various multi purposes. We should determine the design considerations for PAMS in a Korean RR based on the design state analysis. Thus, this paper proposes strategies on the design considerations for the PAMS of a Korean RR

  5. Visual and intelligent transients and accidents analyzer based on thermal-hydraulic system code

    International Nuclear Information System (INIS)

    Meng Lin; Rui Hu; Yun Su; Ronghua Zhang; Yanhua Yang

    2005-01-01

    Full text of publication follows: Many thermal-hydraulic system codes were developed in the past twenty years, such as RELAP5, RETRAN, ATHLET, etc. Because of their general and advanced features in thermal-hydraulic computation, they are widely used in the world to analyze transients and accidents. But there are following disadvantages for most of these original thermal-hydraulic system codes. Firstly, because models are built through input decks, so the input files are complex and non-figurative, and the style of input decks is various for different users and models. Secondly, results are shown in off-line data file form. It is not convenient for analysts who may pay more attention to dynamic parameters trend and changing. Thirdly, there are few interfaces with other program in these original thermal-hydraulic system codes. This restricts the codes expanding. The subject of this paper is to develop a powerful analyzer based on these thermal-hydraulic system codes to analyze transients and accidents more simply, accurately and fleetly. Firstly, modeling is visual and intelligent. Users build the thermalhydraulic system model using component objects according to their needs, and it is not necessary for them to face bald input decks. The style of input decks created automatically by the analyzer is unified and can be accepted easily by other people. Secondly, parameters concerned by analyst can be dynamically communicated to show or even change. Thirdly, the analyzer provide interface with other programs for the thermal-hydraulic system code. Thus parallel computation between thermal-hydraulic system code and other programs become possible. In conclusion, through visual and intelligent method, the analyzer based on general and advanced thermal-hydraulic system codes can be used to analysis transients and accidents more effectively. The main purpose of this paper is to present developmental activities, assessment and application results of the visual and intelligent

  6. ABOUT THE SPECIAL INVESTIGATIONS OF THE PROTECTION OF THE TECHNICAL SECURITY SYSTEMS AGAINST INFORMATION LEAKAGE DUE TO THE ACOUSTO-ELECTRICAL TRANSFORMATIONS

    Directory of Open Access Journals (Sweden)

    A. P. Durakovskiy

    2016-12-01

    Full Text Available None of the critically important facilities can operate without the engineered safety system. Functionally varied security networks or a fire alarm system can refer to this system as well as safety and reliability which are provided by secured energy, water and heating supply. In the process of attestation according to the requirements of information security of information objects with such technical means, it is necessary to conduct special investigations of protection against leakage of acoustic speech information through the channels of the acousto-electrical transformations (AET. There are major aspects in the data leak via AET, which currently include the following: lack of and /or obtaining legal and safety norms to regulate specified parameters; lack of the automated hardware and software system for some AET variations to carry out measurements; lack of specified safety equipment for some AET variations; lack of shelter security units; high costs of AET measurement and control units; and low measurement repeatability.

  7. Fusion radioactivity confinement and application to postulated ITER accidents

    International Nuclear Information System (INIS)

    Piet, S.J.; Brereton, S.J.

    1991-01-01

    An assessment of the ITER radioactivity confinement shows reduction of potential accidental releases to the environment by two orders of magnitude. Important credits are the 1% volume/day confinement leakage rate, radioactivity decay for short-lived isotopes, resumption of detritiation/negative pressure within seven days of the accident, and wind meander during the slow confinement leakage. Achieving this two order of magnitude credit in practice requires appropriate design details, especially the leakage rate and detritiation/negative pressure equipment, and research to validate some key assumptions. The confinement maximizes dependence on passive safety features, thereby working toward using fusion's potential safety advantages. The confinement includes several confinement zones with varying human access allowances. Some confinement areas are normally isolated from the environment, the closed ventilation zone. Some areas have an inert cover gas to inhibit combustion. If future assessments of accidental overpressure show the need, we propose a filter/vent system. This report documents our work for the ITER Conceptual Design Activity (CDA). The report is consistent with the final CDA design reports and descriptions, except that our analysis includes a filter/vent. For gaseous or vapor tritium and for most activated aerosols, the reference release fraction is about 2%. For short-lived tungsten-rhenium aerosols, the reference release fraction is somewhat lower, as low as 0.5% for some accident scenarios. Even without resumption of detritiation/decontamination or negative pressure within seven days of the accident, the release fraction for stays below 4%

  8. Development of filter module for passive filtration and accident gas release confinement system for NPP

    International Nuclear Information System (INIS)

    Yelizarov, P.G.; Efanov, A.D.; Martynov, P.N.; Masalov, D.P.; Osipov, V.P.; Yagodkin, I.V.

    2005-01-01

    Full text of publication follows: One of the urgent problems of the safe NPP operation is air cleaning from radioactive aerosols and volatile iodine compounds under the accident operation conditions of NPP. A principally new passive accident gas release confinement system is used as the basis of the designs of new generation reactor power blocks under the-beyond-design-basis accident conditions with total loss of current. The basic structural component of the passive filtration system (PFS) is the filter-sorber being heated up to 300 deg. C. The filter-sorber represents a design consisting of 150 connected in parallel two-step filtering modules. The first step is intended to clean air from radioactive aerosols, the second one - to clean air from radioactive iodine and its volatile compounds. The filter-sorber is located in the upper point of the exterior protection shell. Due to natural convection, it provides confinement of r/a impurities and controlled steam-gas release from the inter-shell space into atmosphere. The basic specific design feature is the two-section design of the PFS filter module consisting of a coarse-cleaning section and a fine-cleaning section. A combination of layer-by-layer put filtering materials on the basis of glass fiber and metal fiber. The pilot PFS filter module specimen tests run in conditions modeling accident situation indicated that at a filtration rate of 0,3 cm/s the aerodynamic resistance of the module does not exceed 12 Pa, the filtration effectiveness equals 99,99 % in terms of aerosol, no less than 99,9% in terms of radioactive 131 I and no less than 99,0% in terms of organic compounds of iodine (CH 3 131 I); the dust capacity amounts to a value above 50 g/m 2 . The obtained results of tests comply with the design requirements imposed on the PFS filter-sorber module. (authors)

  9. Radiological aspects of nuclear accident scenarios. Volume 2 the Rade-Aid system post-Chernobyl action

    International Nuclear Information System (INIS)

    Sinnaeve, J.

    1991-01-01

    In the event of a nuclear accident, there is a need for a rapid assessment of the resulting levels of environmental contamination in order to facilitate decisions on possible countermeasures. Volume 2 describes the RADE-AID project to develop a computer system which can be used to support the formulation of decisions on countermeasures following an accidental release of radionuclides. The system is intended as an aid following an actual accident and a tool for assistance in planning and training

  10. A system of safety management practices and worker engagement for reducing and preventing accidents: an empirical and theoretical investigation.

    Science.gov (United States)

    Wachter, Jan K; Yorio, Patrick L

    2014-07-01

    The overall research objective was to theoretically and empirically develop the ideas around a system of safety management practices (ten practices were elaborated), to test their relationship with objective safety statistics (such as accident rates), and to explore how these practices work to achieve positive safety results (accident prevention) through worker engagement. Data were collected using safety manager, supervisor and employee surveys designed to assess and link safety management system practices, employee perceptions resulting from existing practices, and safety performance outcomes. Results indicate the following: there is a significant negative relationship between the presence of ten individual safety management practices, as well as the composite of these practices, with accident rates; there is a significant negative relationship between the level of safety-focused worker emotional and cognitive engagement with accident rates; safety management systems and worker engagement levels can be used individually to predict accident rates; safety management systems can be used to predict worker engagement levels; and worker engagement levels act as mediators between the safety management system and safety performance outcomes (such as accident rates). Even though the presence of safety management system practices is linked with incident reduction and may represent a necessary first-step in accident prevention, safety performance may also depend on mediation by safety-focused cognitive and emotional engagement by workers. Thus, when organizations invest in a safety management system approach to reducing/preventing accidents and improving safety performance, they should also be concerned about winning over the minds and hearts of their workers through human performance-based safety management systems designed to promote and enhance worker engagement. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Analysis of the Processes in Spent Fuel Pools in Case of Loss of Heat Removal due to Water Leakage

    Directory of Open Access Journals (Sweden)

    Algirdas Kaliatka

    2013-01-01

    Full Text Available The safe storage of spent fuel assemblies in the spent fuel pools is very important. These facilities are not covered by leaktight containment; thus, the consequences of overheating and melting of fuel in the spent fuel pools can be very severe. On the other hand, due to low decay heat of fuel assemblies, the processes in pools are slow in comparison with processes in reactor core during LOCA accident. Thus, the accident management measures play a very important role in case of some accidents in spent fuel pools. This paper presents the analysis of possible consequences of fuel overheating due to leakage of water from spent fuel pool. Also, the accident mitigation measure, the late injection of water was evaluated. The analysis was performed for the Ignalina NPP Unit 2 spent fuel pool, using system thermal hydraulic code for severe accident analysis ATHLET-CD. The phenomena, taking place during such accident, are discussed. Also, benchmarking of results of the same accident calculation using ASTEC and RELAP/SCDAPSIM codes is presented here.

  12. University student's education after Fukushima nuclear leakage crisis

    International Nuclear Information System (INIS)

    Dou Daying; Gu Jianzhong; Zheng Jianying

    2012-01-01

    Fukushima nuclear leakage crisis after 3.11 earthquake and tsunami, the horrible INES-7 accident warns the colleagues all over the world. Own much to the experts' reports on public media, INES classification, basic knowledge of nuclear reactor, nuclear safety and protection had been discussed and brain-stormed in detail. (authors)

  13. Assessing Agulhas leakage

    NARCIS (Netherlands)

    van Sebille, E.

    2009-01-01

    Agulhas leakage, the water that flows from the Indian Ocean to the Atlantic Ocean, plays an important role in the circulation of the Atlantic Ocean. The magnitude of this flux of warm and saline Indian Ocean water into the much colder and fresher Atlantic Ocean can be related to the strength of the

  14. Methane leakage during the evolution of petroleum systems in the Western Canada Sedimentary Basin and the Central Graben area of the North Sea

    Science.gov (United States)

    Berbesi, L. A.; di Primio, R.; Anka, Z.; Horsfield, B.

    2012-04-01

    Around 500 to 600 Tg (1 Tg = 1012 g) of methane enter the atmosphere every year, mainly as product of microbial processes and combustion of fossil fuels and burning biomass. The importance of another source, the geologic emissions of methane, is up to now only loosely constrained. In this study, we addressed the potential methane emissions during the geological evolution of the Western Canada sedimentary basin (WCSB), which holds the largest oil sand accumulations in the world, and the Central Graben area of the North Sea. In the case of the WCSB, thermogenic gas generation and leakage at the sediment surface were addressed through 3D petroleum systems modeling. In this basin, the accumulated oil experienced intense biodegradation that resulted in large masses of biogenic methane. We quantified this latter mass though a two-step mass balance approach. Firstly, we estimated the rate of petroleum degradation and the magnitude of petroleum loss. After this, we calculated the mass of biogenic methane generated using a model that assumes hexadecane (C16H34) as representative of the saturated compounds (Zengler et al., 1999). Our 3D model suggests that 90000-150000 Tg of dry gas (mostly methane) could have leaked during the interval from 80 Ma to 60 Ma. Therefore, uniform leakage rates would have been in the order of 10-3-10-2 Tg yr-1. Biogenic methane generation could have taken place at rates of 10-4 to 10-2 Tg yr-1. However, the effective mass of thermogenic and biogenic methane reaching the atmosphere might have been up to 90% lower than calculated here due to methanotrophic consumption in soils (Etiope and Klusman, 2002). We addressed the thermogenic gas generation and leakage in the Central Graben through two different methods. The first is based on a previous 3D petroleum system modeling of the region (Neumann, 2006). The second consisted of calculating the mass of generated petroleum based on source rock extension and properties (Schmoker, 1994), and then

  15. Assisting emergency operating procedures execution with AMAS, an Accident Management Advisor System

    International Nuclear Information System (INIS)

    Guarro, S.; Milici, T.; Wu, J.S.; Apostolakis, G.

    2004-01-01

    In an accident situation, because any decisions that the operators make will depend on how instrumentation readings are ultimately interpreted, the issue of instrument uncertainty is of paramount importance. This uncertainty exists because instrument readings may not be available in the desired form - i.e., only indirect readings for a parameter of interest may exist, with uncertainty on which physical models may be used to deduce its value from these indirect indications -, or because readings may be coming from instruments whose accuracy and reliability in the face of the severe conditions produced by the accident are far from what may be expected under normal operating conditions. In following the EOPs, the operators must rely on instrumentation whose readings may not reflect the real situation. The Accident Management Advisor System (AMAS) is a decision aid intended to supplement plant Emergency Operating Procedures (EOPs) by accounting for instrumentation uncertainty, and by alerting the operators if they are on the wrong procedures, or otherwise performing an action that is not optimal in terms of preventing core damage. In AMAS, the availability and reliability of certain important instrument readings is treated in probabilistic, rather than deterministic terms. This issue is discussed in greater detail later in the paper, since it relates to one of the key characteristics of the AMAS decision aid. (author)

  16. The United States Department of Energy (DOE) Computerized Accident/Incident Reporting System (CAIRS)

    International Nuclear Information System (INIS)

    Briscoe, G.J.

    1993-01-01

    The Department of Energy's (DOE) Computerized Accident/Incident Reporting System (CAIRS) is a comprehensive data base containing more than 50,000 investigation reports of injury/illness, property damage and vehicle accident cases representing safety data from 1975 to the present for more than 150 DOE contractor organizations. A special feature is that the text of each accident report is translated using a controlled dictionary and rigid sentence structure called Factor Relationship and Sequence of Events (FRASE) that enhances the ability to retrieve specific types of information and to perform detailed analyses. DOE summary and individual contractor reports are prepared quarterly and annually. In addition, ''Safety Performance Profile'' reports for individual organizations are prepared to provide advance information to appraisal teams, and special topical reports are prepared for areas of concern such as an increase in the number of security injuries or environmental releases. The data base is open to all DOE and Contractor registered users with no access restrictions other than that required by the Privacy Act

  17. A decision support system for emergency response to major nuclear accidents

    International Nuclear Information System (INIS)

    Papazoglou, I.A.; Christou, M.D.

    1997-01-01

    A methodology for the optimization of the short-term emergency response in the event of a nuclear accident is presented. The method seeks an optimum combination of protective actions in the presence of a multitude of conflicting objectives and under uncertainty. Conflicting objectives arise in the attempt to minimize simultaneously the potential adverse effects of an accident and the associated socioeconomic impacts. Additional conflicting objectives arise whenever an emergency plan tends to decrease a particular health effect, such as acute deaths, while it increases another, such as latent deaths. The uncertainty is due to the multitude of possible accident scenarios and their respective probability of occurrence, the stochastic variability in the weather conditions, and the variability and/or lack of knowledge of the parameters of the risk assessment models. A multiobjective optimization approach is adopted. An emergency protection plan consists of defining a protective action at each spatial cell around the plant. Three criteria are used as the objective functions of the problem, namely, acute fatalities, latent effects, and socioeconomic cost. The optimization procedure defines the efficient frontier, i.e., all emergency plans that are not dominated by another in all three criteria. No value trade-offs are necessary up to this point. The most preferred emergency plan is then chosen among the set of efficient plans. Finally, the methodology is integrated into a computerized decision support system, and its use is demonstrated in a realistic application

  18. Analysis and model testing of a Super Tiger Type B waste transport system in accident environments

    International Nuclear Information System (INIS)

    May, R.A.; Yoshimura, H.R.; Romesberg, L.E.; Joseph, B.J.

    1980-01-01

    Sandia National Laboratories is investigating the response of a Type B packaging containing drums of contact-handled transuranic waste (CH-TRU) as a part of a program to evaluate the adequacy of experimental and analytical methods for assessing the safety of waste transport systems in accident environments. A US NRC certified Type B package known as the Super Tiger was selected for the study. This overpack consists of inner and outer steel shells separated by rigid polyurethane foam and can be used for either highway or rail transportation. Tests using scale models of the vehicular system are being conducted in conjunction with computer analyses

  19. CO2leakage from carbon dioxide capture and storage (CCS) systems affects organic matter cycling in surface marine sediments.

    Science.gov (United States)

    Rastelli, Eugenio; Corinaldesi, Cinzia; Dell'Anno, Antonio; Amaro, Teresa; Greco, Silvestro; Lo Martire, Marco; Carugati, Laura; Queirós, Ana M; Widdicombe, Stephen; Danovaro, Roberto

    2016-12-01

    Carbon dioxide capture and storage (CCS), involving the injection of CO 2 into the sub-seabed, is being promoted worldwide as a feasible option for reducing the anthropogenic CO 2 emissions into the atmosphere. However, the effects on the marine ecosystems of potential CO 2 leakages originating from these storage sites have only recently received scientific attention, and little information is available on the possible impacts of the resulting CO 2 -enriched seawater plumes on the surrounding benthic ecosystem. In the present study, we conducted a 20-weeks mesocosm experiment exposing coastal sediments to CO 2 -enriched seawater (at 5000 or 20,000 ppm), to test the effects on the microbial enzymatic activities responsible for the decomposition and turnover of the sedimentary organic matter in surface sediments down to 15 cm depth. Our results indicate that the exposure to high-CO 2 concentrations reduced significantly the enzymatic activities in the top 5 cm of sediments, but had no effects on subsurface sediment horizons (from 5 to 15 cm depth). In the surface sediments, both 5000 and 20,000 ppm CO 2 treatments determined a progressive decrease over time in the protein degradation (up to 80%). Conversely, the degradation rates of carbohydrates and organic phosphorous remained unaltered in the first 2 weeks, but decreased significantly (up to 50%) in the longer term when exposed at 20,000 ppm of CO 2 . Such effects were associated with a significant change in the composition of the biopolymeric carbon (due to the accumulation of proteins over time in sediments exposed to high-pCO 2 treatments), and a significant decrease (∼20-50% at 5000 and 20,000 ppm respectively) in nitrogen regeneration. We conclude that in areas immediately surrounding an active and long-lasting leak of CO 2 from CCS reservoirs, organic matter cycling would be significantly impacted in the surface sediment layers. The evidence of negligible impacts on the deeper sediments should be

  20. Severe accident testing of a personnel airlock

    International Nuclear Information System (INIS)

    Clauss, D.B.; Parks, M.B.; Julien, J.T.; Peters, S.W.

    1988-01-01

    Sandia National Laboratories (Sandia) is investigating the leakage potential of mechanical penetrations as part of a research program on containment integrity under severe accident loads for the U.S. Nuclear Regulatory Commission (NRC). Barnes et al. (1984) and Shackelford et al. (1985) identified leakage from personnel airlocks as an important failure mode of containments subject to severe accident loads. However, these studies were based on relatively simple analysis methods. The complex structural interaction between the door, gasket, and bulkhead in personnel airlocks makes analytical evaluation of leakage difficult. In order to provide data to validate methods for evaluating the leakage potential, a full-size personnel airlock was subject to simulated severe accident loads consisting of pressure and temperature up to 300 psig and 800 degrees F. The test was conducted at Chicago Bridge and Iron under contract to Sandia. The authors provide a detailed report on the test program

  1. Assessment of chemical processes for the post-accident decontamination of reactor-coolant systems. Final report

    International Nuclear Information System (INIS)

    Munson, L.F.; Card, C.J.; Divine, J.R.

    1983-02-01

    Previously used chemical decontamination processes and potentially useful new decontamination processes were examined for the usefulness following a reactor accident. Both generic fuel damage accidents and the accident at TMI-2 were considered. A total of fourteen processes were evaluated. Process evaluation included data in the following categories: technical description of the process, recorded past usage, effectiveness, process limitation, safety consideration, and waste management. These data were evaluated, and cost considerations were presented along with a description of the applicability of the process to TMI-2 and development and demonstration needs. Specific recommendations regarding a primary-system decontamination development program to support TMI-2 recovery were also presented

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

    Energy Technology Data Exchange (ETDEWEB)

    Ganter, J.H.

    1999-02-01

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

  3. An Ontology-Underpinned Emergency Response System for Water Pollution Accidents

    Directory of Open Access Journals (Sweden)

    Xiaoliang Meng

    2018-02-01

    Full Text Available With the unceasing development and maturation of environment geographic information system, the response to water pollution accidents has been digitalized through the combination of monitoring sensors, management servers, and application software. However, most of these systems only achieve the basic and general geospatial data management and functional process tasks by adopting mechanistic water-quality models. To satisfy the sustainable monitoring and real-time emergency response application demand of the government and public users, it is a hotspot to study how to make the water pollution information being semantic and make the referred applications intelligent. Thus, the architecture of the ontology-underpinned emergency response system for water pollution accidents is proposed in this paper. This paper also makes a case study for usability testing of the water ontology models, and emergency response rules through an online water pollution emergency response system. The system contributes scientifically to the safety and sustainability of drinking water by providing emergency response and decision-making to the government and public in a timely manner.

  4. Transformerless photovoltaic inverters with leakage current and pulsating power elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Wang, H.

    2015-01-01

    This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV-to-ground parasi......This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV...

  5. Accident localization system with jet condensers for VVER 440-V 230 NPP at Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Murani, J.

    1995-01-01

    The operational safety of the V1 nuclear power plant (NPP) is unsatisfactory and does not correspond to present requirements as to nuclear safety. Further NPP operation after 1995 is conditional on nuclear safety enhancement to a level comparable with that in West European countries. This aim should be achieved by a principal reconstruction involving in addition to others also backfitting the V1 NPP with technical facilities aimed at coping with a design basis accident (DBA).To cope with such an accident the Power Equipment Research Institute (VUEZ) designed an accident localization system with jet condensers. This system consists of (a) an air trap (one for each unit, mutually interconnected) with an expansion bell enclosed within, placed on a plate with 200 pipes of jet condensers passing through, and (b) a connecting duct between the hermetic zone and the air trap. The vertical jet condenser is an essential element of the system designed for steam condensation. Apart from condensation it serves as a water seal separating units 1 and 2.Demonstration tests of the jet condenser (model 1:1) condensing function were carried out at the testing unit of the All-Union Research Institute for NPP Operation (VNIIAES), Moscow in Kashir, 11-22 September 1992. These experiments proved the jet condenser ability to ensure complete condensation of the steam produced. Experimental verification of the sealing function (model 1:1) was carried out at the testing unit of the VUEZ Tlmace. These experiments concerning the dynamics and overpressure in the free space above the pool were close to the conditions in the air trap during DBA. The jet condenser height was proved to be sufficient to ensure the sealing function. Design and experimental work has been implemented in close cooperation with Russian experts Mr. V.N. Bulynin from the VNIIAES, Moscow, and Mr. M.V. Kuznecov from the Scientific and Engineering Center for Nuclear and Radiological Safety, Moscow. (orig.)

  6. Development of highly reliable power and communication system for essential instruments under severe accidents in NPP

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hwan; Jang, Gi Chan; Shin, Sung Min; Kang, Hyun Gook; Rim, Chun Taek [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Soo Ill [I and C Group, Korea Hydro and Nuclear Power Co., Ltd, Central Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to 627 .deg. C and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

  7. Development of Highly Reliable Power and Communication System for Essential Instruments Under Severe Accidents in NPP

    Directory of Open Access Journals (Sweden)

    Bo Hwan Choi

    2016-10-01

    Full Text Available This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to 627°C and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

  8. Methodology for time-dependent reliability analysis of accident sequences and complex reactor systems

    International Nuclear Information System (INIS)

    Paula, H.M.

    1984-01-01

    The work presented here is of direct use in probabilistic risk assessment (PRA) and is of value to utilities as well as the Nuclear Regulatory Commission (NRC). Specifically, this report presents a methodology and a computer program to calculate the expected number of occurrences for each accident sequence in an event tree. The methodology evaluates the time-dependent (instantaneous) and the average behavior of the accident sequence. The methodology accounts for standby safety system and component failures that occur (a) before they are demanded, (b) upon demand, and (c) during the mission (system operation). With respect to failures that occur during the mission, this methodology is unique in the sense that it models components that can be repaired during the mission. The expected number of system failures during the mission provides an upper bound for the probability of a system failure to run - the mission unreliability. The basic event modeling includes components that are continuously monitored, periodically tested, and those that are not tested or are otherwise nonrepairable. The computer program ASA allows practical applications of the method developed. This work represents a required extension of the presently available methodology and allows a more realistic PRA of nuclear power plants

  9. A route-specific system for risk assessment of radioactive materials transportation accidents

    International Nuclear Information System (INIS)

    Moore, J.E.; Sandquist, G.M.; Slaughter, D.M.

    1995-01-01

    A low-cost, powerful geographic information system (GIS) that operates on a personal computer was integrated into a software system to provide route specific assessment of the risks associated with the atmospheric release of radioactive and hazardous materials in transportation accidents. The highway transportation risk assessment (HITRA) software system described here combines a commercially available GIS (TransCAD) with appropriate models and data files for route- and accident-specific factors, such as meteorology, dispersion, demography, and health effects to permit detailed analysis of transportation risk assessment. The HITRA system allows a user to interactively select a highway or railroad route from a GIS database of major US transportation routes. A route-specific risk assessment is then performed to estimate downwind release concentrations and the resulting potential health effects imposed on the exposed population under local environmental and temporal conditions. The integration of GIS technology with current risk assessment methodology permits detailed analysis coupled with enhanced user interaction. Furthermore, HITRA provides flexibility and documentation for route planning, updating and improving the databases required for evaluating specific transportation routes, changing meteorological and environmental conditions, and local demographics

  10. Sustainable management of leakage from wastewater pipelines.

    Science.gov (United States)

    DeSilva, D; Burn, S; Tjandraatmadja, G; Moglia, M; Davis, P; Wolf, L; Held, I; Vollertsen, J; Williams, W; Hafskjold, L

    2005-01-01

    Wastewater pipeline leakage is an emerging concern in Europe, especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritize proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions, and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilizes these models to predict the condition of pipes in individual zones, and to optimize the utilization of rehabilitation resources by targeting the areas with the highest leakage rates.

  11. Water Leakage and Nitrate Leaching Characteristics in the Winter Wheat–Summer Maize Rotation System in the North China Plain under Different Irrigation and Fertilization Management Practices

    Directory of Open Access Journals (Sweden)

    Shufeng Chen

    2017-02-01

    Full Text Available Field experiments were carried out in Huantai County from 2006 to 2008 to evaluate the effects of different nitrogen (N fertilization and irrigation management practices on water leakage and nitrate leaching in the dominant wheat–maize rotation system in the North China Plain (NCP. Two N fertilization (NF1, the traditional one; NF2, fertilization based on soil testing and two irrigation (IR1, the traditional one; IR2, irrigation based on real-time soil water content monitoring management practices were designed in the experiments. Water and nitrate amounts leaving the soil layer at a depth of 2.0 m below the soil surface were calculated and compared. Results showed that the IR2 effectively reduced water leakage and nitrate leaching amounts in the two-year period, especially in the winter wheat season. Less than 10 percent irrigation water could be saved in a dry winter wheat season, but about 60 percent could be saved in a wet winter wheat season. Besides, 58.8 percent nitrate under single NF2IR1 and 85.2 percent under NF2IR2 could be prevented from leaching. The IR2 should be considered as the best management practice to save groundwater resources and prevent nitrate from leaching. The amounts of N input play a great role in affecting nitrate concentrations in the soil solutions in the winter wheat–summer maize rotation system. The NF2 significantly reduced N inputs and should be encouraged in ordinary agricultural production. Thus, nitrate leaching and groundwater contamination could be alleviated, but timely N supplement might be needed under high precipitation condition.

  12. Analysis on the Role of RSG-GAS Pool Cooling System during Partial Loss of Heat Sink Accident

    Science.gov (United States)

    Susyadi; Endiah, P. H.; Sukmanto, D.; Andi, S. E.; Syaiful, B.; Hendro, T.; Geni, R. S.

    2018-02-01

    RSG-GAS is a 30 MW reactor that is mostly used for radioisotope production and experimental activities. Recently, it is regularly operated at half of its capacity for efficiency reason. During an accident, especially loss of heat sink, the role of its pool cooling system is very important to dump decay heat. An analysis using single failure approach and partial modeling of RELAP5 performed by S. Dibyo, 2010 shows that there is no significant increase in the coolant temperature if this system is properly functioned. However lessons learned from the Fukushima accident revealed that an accident can happen due to multiple failures. Considering ageing of the reactor, in this research the role of pool cooling system is to be investigated for a partial loss of heat sink accident which is at the same time the protection system fails to scram the reactor when being operated at 15 MW. The purpose is to clarify the transient characteristics and the final state of the coolant temperature. The method used is by simulating the system in RELAP5 code. Calculation results shows the pool cooling systems reduce coolant temperature for about 1 K as compared without activating them. The result alsoreveals that when the reactor is being operated at half of its rated power, it is still in safe condition for a partial loss of heat sink accident without scram.

  13. The program system UFOMOD for assessing the consequences of nuclear accidents

    International Nuclear Information System (INIS)

    Ehrhardt, J.; Burkart, K.; Hasemann, I.; Matzerath, C.; Panitz, H.J.; Steinhauer, C.

    1988-10-01

    The programm system UFOMOD is a completely new accident consequence assessment (ACA) code. Its structure and modelling is based on the experience gained from applications of the old UFOMOD code during and after the German Risk Study - Phase A, the results of scientific investigations performed within the ongoing Phase B and the CEC-project MARIA, and the requirements resulting from the extended use of ACAs to help in decision-making. One of the most important improvements is the introduction of different trajecotry models for describing atmospheric dispersion in the near range and at larger distances. Emergency actions and countermeasures modelling takes into account recommendations of international commissions. The dosimetric models contain completely new age-, sex- and time-dependent data of dose-conversion factors for external and internal radiation; the ingestion pathway is modelled to consider seasonal dependencies. New dose-risk-relationships for stochastic and non-stochastic health effects are implemented; a special algorithm developed for ACA codes allows individual and collective leukemia and cancer risks to be presented as a function of time after the accident. According to the modular structure of the new program system UFOMOD, an easy access to parameter values and the results of the various submodels exists what facilitates sensitivity and uncertainty analyses. (orig.) [de

  14. The Effect of Containment Filtered Venting System on the Severe Accident Management Strategies of the CANDU6 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Youngho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In March, 2011, Fukushima daichi nuclear power plants experienced a long term station blackout and severe core damages and released a large amount of radioactive materials outside of the plants. After this accident Nuclear Safety and Security Commission (NSSC) decided to install a filtered containment venting system (CFVS) at all the operating nuclear power plants in Korean. To comply with NSSC's request, Wolsong Unit 1 has installed a CFVS. Current severe accident management guidance, which does not consider a CFVS has 6 severe accident management strategies for CANDU6 plant. These strategies are inject in to the primary heat transport system (PHTS), inject in to the calandria, inject into the calandria vault, reduce fission product releases, control containment conditions, reduce containment hydrogen. The CFVS is designed to open and to close isolation valves by an operator. An operator opens the CFVS isolation valve when the containment pressure exceeds the design pressure (124 kPa(g)) and closes isolation valves when the containment pressure decreases below 50 kPa(g). The operation of the CFVS not only influences the current strategies (adds a means of controlling containment conditions) but also requires the new strategies. This paper discusses the necessity of the new strategies, such as the prevention of containment vacuum and the injection into the containment. The necessity of the additional severe accident management strategies for CANDU6 plants which installed a CFVS is evaluated. The operation of a CFVS affects the water inventory in the basement also, but not significantly. The SBO accident requires the water injection into the containment at least 4 days after an accident initiation if a passive spray system fails. If a spray system operates, then the injection into the containment is required more than 10 days after an accident initiation even though a CFVS operates.

  15. A Novel Thermal-Mechanical Detection System for Reactor Pressure Vessel Bottom Failure Monitoring in Severe Accidents

    International Nuclear Information System (INIS)

    Bi, Daowei; Bu, Jiangtao; Xu, Dongling

    2013-06-01

    Following the Fukushima Daiichi nuclear accident in Japan, there is an increased need of enhanced capabilities for severe accident management (SAM) program. Among others, a reliable method for detecting reactor pressure vessel (RPV) bottom failure has been evaluated as imperative by many utility owners. Though radiation and/or temperature measurement are potential solutions by tradition, there are some limitations for them to function desirably in such severe accident as that in Japan. To provide reliable information for assessment of accident progress in SAM program, in this paper we propose a novel thermal-mechanical detection system (TMDS) for RPV bottom failure monitoring in severe accidents. The main components of TMDS include thermally sensitive element, metallic cables, tension controlled switch and main control room annunciation device. With TMDS installed, there shall be a reliable means of keeping SAM decision-makers informed whether the RPV bottom has indeed failed. Such assurance definitely guarantees enhancement of severe accident management performance and significantly improve nuclear safety and thus protect the society and people. (authors)

  16. Rade-aid a decision support system to evaluate countermeasures after a radiological accident

    International Nuclear Information System (INIS)

    Wagenaar, G.; Van Den Bosch, C.J.H.; Weger, D. de.

    1990-01-01

    After Chernobyl the authorities in many countries were overwhelmed by the enormous amount of information that was being generated by measuring and monitoring programs. In making decisions, this information had to be combined with the results of specific countermeasures, in order to determine the optimal strategy with respect to a large number of consequences. The development of RADE-AID, the Radiological Accident Decision AIDing system, is aimed at providing a powerful tool in the decision-making process. RADE-AID is developed by TNO (The Netherlands) in a joint contract with KfK (FRG) and NRPB (UK). In the first phase a demonstration system will be built, called RADE-AID/D. RADE-AID/D will be used as a decision support system in the intermediate and late phase after a radiological accident. RADE-AID/D will consider countermeasures with respect to external exposure and internal exposure by food ingestion. Countermeasures are evaluated considering reduction in doses and in numbers of health effects, costs, and social effects. The paper covers the structure of the program, presentation of data and results, and the decision analysis technique that is being used. This decision analysis part is an important feature of the system; an advanced decision analysis technique is used, that is able to compare data of varying nature. Furthermore the place of RADE-AID in the decision-making process will be treated. RADE-AID/D is an interactive computer program, that offers the user the possibility to enter relevant data and to have data and results displayed in a variety of ways. Furthermore the system contains an advanced decision analysis technique, that is able to compare data of varying nature. Input data for the decision analysis calculations are provided by models from UFOMOD and MARC-codes

  17. 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

  18. Determination of leakage areas in nuclear piping

    International Nuclear Information System (INIS)

    Keim, E.

    1997-01-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack

  19. Determination of leakage areas in nuclear piping

    Energy Technology Data Exchange (ETDEWEB)

    Keim, E. [Siemens/KWU, Erlangen (Germany)

    1997-04-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.

  20. Pickering unit 1 containment leakage characterization

    International Nuclear Information System (INIS)

    Zakaib, G.D.

    1994-01-01

    Results of the design pressure test carried out on Pickering Reactor Building number 1 during late 1992 showed that the leakage rate of the building was close to the safety analysis value of 2.7% contained mass per hour at the design pressure of 41.4 kPa(g) and was significantly higher than that reported after the previous test conducted in the spring of 1987. This unexpected finding initiated the longest and the most comprehensive containment leakage investigation ever undertaken by Ontario Hydro. A thorough investigation of leakage behaviour by repeated testing, inspections, leak search and analysis was launched. The extensive leak search effort included items such as: leak source detection by soap solution application, use of ultrasonic detectors, fogging and tracer gas techniques, systematic systems isolation, thermal imaging of the exterior, and quantification of leak sites by flowmeter and bagging. Using a specially designed volumetric technique, the root cause of the problem was finally confirmed as being due to 'pressure dependent laminar leakage' through the hairline cracks in the dome concrete. Structural analysis indicated that the thermal gradients and pressure loading combined to cause the cracking early in the structure's operating history and that overall structural integrity has not been compromised. Leakage rate analysis using a new fluid mechanics model augmented by the effect of thermal strains indicated that the leakage could be significantly less under certain transient temperature gradient conditions. Several options for repairing the dome were considered by a multidisciplinary team and it was finally decided to apply a specially engineered multilayer elastomeric coating to the exterior concrete surface. When the unit was re-tested in October 1993, a dramatic ten-fold improvement in leakage rate (down to 0.25%/h at design pressure) was observed. This is lower than even the commissioning results and comparable to the performance of newer units

  1. Quantifying information leakage of randomized protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Malacaria, Pasquale

    2015-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model deterministic and probabilistic systems. By using a methodology generalizing the lattice of information approach we model refined attacker...... on the Onion Routing protocol....

  2. Quality systems for radiotherapy: Impact by a central authority for improved accuracy, safety and accident prevention

    International Nuclear Information System (INIS)

    Jaervinen, H.; Sipilae, P.; Parkkinen, R.; Kosunen, A.; Jokelainen, I.

    2001-01-01

    High accuracy in radiotherapy is required for the good outcome of the treatments, which in turn implies the need to develop comprehensive Quality Systems for the operation of the clinic. The legal requirements as well as the recommendation by professional societies support this modern approach for improved accuracy, safety and accident prevention. The actions of a national radiation protection authority can play an important role in this development. In this paper, the actions of the authority in Finland (STUK) for the control of the implementation of the new requirements are reviewed. It is concluded that the role of the authorities should not be limited to simple control actions, but comprehensive practical support for the development of the Quality Systems should be provided. (author)

  3. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents

    International Nuclear Information System (INIS)

    Shi, Shenggang; Cao, Jingcan; Feng, Li; Liang, Wenyan; Zhang, Liqiu

    2014-01-01

    Highlights: • Different chemical pollution accidents were simplified using the event tree analysis. • Emergency disposal technique plan repository of chemicals accidents was constructed. • The technique evaluation index system of chemicals accidents disposal was developed. • A combination of group decision and analytical hierarchy process (AHP) was employed. • Group decision introducing similarity and diversity factor was used for data analysis. - Abstract: The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012

  4. An international intercomparison of national network systems used to provide early warning of a nuclear accident having transboundary implications

    DEFF Research Database (Denmark)

    Thompson, I.M.G.; Andersen, C.E.; Bøtter-Jensen, L.

    2000-01-01

    of these detectors are used. During an accident the data produced by such systems will be exchanged between countries within the European Communities, (EC) and as required by the IAEA's Early Warning Convention between the rest of the world and Europe. It is therefore important to ensure that such data should......Since the Chernobyl accident many countries now operate large national networks of radiation detectors that continuously monitor radiation levels in order to give early warning of nuclear accidents having transboundary implications. The networks are used to provide data to assist in determining...... the action that should be implemented in that country. However, each country has its own unique system of detection. These are based either on Geiger-Muller counters, high pressure ionisation chambers, scintillation detectors, proportional counters, passive detectors or spectrometry systems; or mixtures...

  5. Topological qubit design and leakage

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, R; Slingerland, J K, E-mail: robert.ainsworth@nuim.ie, E-mail: joost@thphys.nuim.ie [Department of Mathematical Physics, National University of Ireland Maynooth, Co. Kildare (Ireland)

    2011-06-15

    We examine how best to design qubits for use in topological quantum computation. These qubits are topological Hilbert spaces associated with small groups of anyons. Operations are performed on these by exchanging the anyons. One might argue that in order to have as many simple single-qubit operations as possible, the number of anyons per group should be maximized. However, we show that there is a maximal number of particles per qubit, namely 4, and more generally a maximal number of particles for qudits of dimension d. We also look at the possibility of having topological qubits for which one can perform two-qubit gates without leakage into non-computational states. It turns out that the requirement that all two-qubit gates are leakage free is very restrictive and this property can only be realized for two-qubit systems related to Ising-like anyon models, which do not allow for universal quantum computation by braiding. Our results follow directly from the representation theory of braid groups, which implies that they are valid for all anyon models. We also make some remarks about generalizations to other exchange groups.

  6. Electromagnetic system for detection and localization of the miners caught by accident in mine

    Science.gov (United States)

    Pronenko, Vira; Dudkin, Fedir

    2016-04-01

    It is well known that the profession of a miner is one of the most dangerous in the world. Among the main causes of the people death in the underground coal mining enterprises is their untimely alerting of the accident, as well as the lack of information for the rescuers about the actual location of the miners after the accident. As world practice shows, the electromagnetic (EM) systems for the search and detection of people across a massive layer of rock are the most effective. Such systems are under development almost half a century in many countries dealing with mine industry. However, substantial progress related to the localization of personnel at a distance at least of 20-30 meters through the rock is not reached. In an emergency situation (failure or destruction of underground infrastructure), personnel search behind and beneath of obstruction should be provided urgently. But none of the standard technologies (RFID, DECT, WiFi, emitting cable), which use the stationary technical devices in mines, do not provide notification of people caught by accident location. The only technology that provides guaranteed delivery of messages about the accident to the mine personnel, regardless of their location and under any destruction in the mine, is low-frequency radio technology able to operate through the thickness of rocks. From the general theoretical considerations, it is clear that the miners localization system requires solving the inverse problem of the magnetic field source coordinates determining using the data of 3-component magnetic field measurements. A fundamentally new approach, based on the measurement of the magnetic field of the miner's responder beacon by two fixed and spaced three-component magnetic field receivers and solution of the inverse problem using the results of the magnetic field measurement, was proposed. As a result, the concept of the equipment for miners beacon search and localization implementation (MILES - miner's location emergency

  7. Aviation Safety Program: Weather Accident Prevention (WxAP) Development of WxAP System Architecture And Concepts of Operation

    Science.gov (United States)

    Grantier, David

    2003-01-01

    This paper presents viewgraphs on the development of the Weather Accident Prevention (WxAP) System architecture and Concept of Operation (CONOPS) activities. The topics include: 1) Background Information on System Architecture/CONOPS Activity; 2) Activity Work in Progress; and 3) Anticipated By-Products.

  8. Learning lessons from accidents with a human and organisational factors perspective: deficiencies and failures of operating experience feedback systems

    International Nuclear Information System (INIS)

    Dechy, N.; Rousseau, J.M.; Jeffroy, F.

    2012-01-01

    This paper aims at reminding the failures of operating experience feedback (OEF) systems through the lessons of accidents and provides a framework for improving the efficiency of OEF processes. The risk is for example to miss lessons from other companies and industrial sectors, or to miss the implementation of adequate corrective actions with the risk to repeat accidents. Most of major accidents have been caused by a learning failure or other organisational factors as a contributing cause among several root causes. Some of the recurring organisational factors are: -) poor recognition of critical components, of critical activities or deficiency in anticipation and detection of errors, -) excessive production pressure, -) deficiency of communication or lack of quality of dialogue, -) Excessive formalism, -) organisational complexity, -) learning deficiencies (OEF, closing feedback loops, lack of listening of whistle-blowers). Some major accidents occurred in the nuclear industry. Although the Three Mile Island accident has multiple causes, in particular, an inappropriate design of the man-machine interface, it is a striking example of the loss of external lessons from incidents. As for Fukushima it is too early to have established evidence on learning failures. The systematic study and organisational analysis of OEF failures in industrial accidents whatever their sector has enabled us to provide a framework for OEF improvements. Five key OEF issues to improve in priority: 1) human and organisational factors analysis of the root causes of the events, 2) listening to the field staff, dissenting voices and whistle-blowers, 3) monitoring of the external events that provide generic lessons, 4) building an alive memory through a culture of accidents with people who become experiences pillars, and 5) the setting of external audit or organisational analysis of the OEF system by independent experts. The paper is followed by the slides of the presentation

  9. Loss-of-Coolant and Loss-of-Flow Accidents in the SEAFP first wall/blanket cooling system

    International Nuclear Information System (INIS)

    Komen, E.M.J.; Koning, H.

    1995-01-01

    This paper presents the RELAP5/MOD3 thermal-hydraulic analysis of three Loss-of-Coolant Accidents (LOCAs) and three Loss-of-Flow Accidents (LOFAs) in the first wall/blanket cooling system of the SEAFP reactor design. The analyses deal with the transient thermal-hydraulic behaviour inside the cooling systems and the temperature development inside the nuclear components. As it appears, the temperature increase in the first wall Be-coating is limited to 30 K when an emergency plasma shutdown is initiated within 10 s following pump trip. (orig.)

  10. CONTAIN model for simulation of accident localisation system at Ignalina NPP in the case of pressure header rupture

    International Nuclear Information System (INIS)

    Rimkevichius, S.; Chesna, B.

    1997-01-01

    Accident localisation system (ALS) at the Ignalina NPP is a system of rooms intended to reduce the pressure inside the rooms and to limit the release of radiation in the case of loose of coolant accident (LOCA). The analysis of effectiveness of ALS and results of calculations in the case of pressure header (PH) rupture using the code CONTAIN (USA) are described in this paper. The calculations were performed using mass and energy release from the broken PH function obtained from RELAP5 (USA) code calculations. Comparative calculations using design function were performed as well. The balance of energy is analyzed. (author). 12 refs., 3 tab., 13 figs

  11. A systemic analysis of patterns of organizational breakdowns in accidents: A case from Helicopter Emergency Medical Service (HEMS) operations

    International Nuclear Information System (INIS)

    Kontogiannis, Tom; Malakis, Stathis

    2012-01-01

    In recent years, many accident models and techniques have shifted their focus from shortfalls in the actions of practitioners to systemic causes in the organization. Accident investigation techniques (e.g., STAMP) have been developed that looked into the flaws of control processes in the organization. Organizational models have looked into general patterns of breakdown related to structural vulnerabilities and gradual degradation of performance. Although some degree of cross-fertilization has been developed between these two trends, safety analysts are left on their own to integrate this gap between control flaws and patterns of organizational breakdown in accident investigation. This article attempts to elaborate the control dynamics of the Systems Theoretic Accident Model and Process (STAMP) technique on the basis of a theoretical model of organizational viability (i.e., the Viable Systems Model). The joint STAMP–VSM framework is applied to an accident from a Helicopter Emergency Medical Service (HEMS) organization to help analysts progress from the analysis of control flaws to the underlying patterns of breakdown. The joint framework may help analysts to rethink the safety organization, model new information loops and constraints, look at the adaptation and steering functions of the organization and finally, develop high leverage interventions. - Highlights: ► This article bridges the gap between two parallel trends in systemic accident models. ► Investigation techniques (i.e., STAMP) have looked into the flaws of safety management processes. ► The literature has highlighted many patterns (or archetypes) of organizational breakdowns. ► The Viable System Model is used with STAMP to link control flaws and organizational breakdowns.

  12. A review of accidents, prevention and mitigation options related to hazardous gases

    International Nuclear Information System (INIS)

    Fthenakis, V.M.

    1993-05-01

    Statistics on industrial accidents are incomplete due to lack of specific criteria on what constitutes a release or accident. In this country, most major industrial accidents were related to explosions and fires of flammable materials, not to releases of chemicals into the environment. The EPA in a study of 6,928 accidental releases of toxic chemicals revealed that accidents at stationary facilities accounted for 75% of the total number of releases, and transportation accidents for the other 25%. About 7% of all reported accidents (468 cases) resulted in 138 deaths and 4,717 injuries ranging from temporary respiratory problems to critical injuries. In-plant accidents accounted for 65% of the casualties. The most efficient strategy to reduce hazards is to choose technologies which do not require the use of large quantities of hazardous gases. For new technologies this approach can be implemented early in development, before large financial resources and efforts are committed to specific options. Once specific materials and options have been selected, strategies to prevent accident initiating events need to be evaluated and implemented. The next step is to implement safety options which suppress a hazard when an accident initiating event occurs. Releases can be prevented or reduced with fail-safe equipment and valves, adequate warning systems and controls to reduce and interrupt gas leakage. If an accident occurs and safety systems fail to contain a hazardous gas release, then engineering control systems will be relied on to reduce/minimize environmental releases. As a final defensive barrier, the prevention of human exposure is needed if a hazardous gas is released, in spite of previous strategies. Prevention of consequences forms the final defensive barrier. Medical facilities close by that can accommodate victims of the worst accident can reduce the consequences of personnel exposure to hazardous gases

  13. Effect of Viscosity on Fuel Leakage Between Lapped Plungers and Sleeves and on the Discharge from a Pump-Injection System

    Science.gov (United States)

    Rothrock, A M; Marsh, E T

    1935-01-01

    Test data and analysis show that the rate of fuel leakage between a lapped plunger and sleeve varies directly with the density of the fuel, the diameter of the plunger, the pressure producing the leakage, and the cube of the mean clearance between the plunger and sleeve. The rate varies inversely as the length of the lapped fit and the viscosity of the fuel. With a mean clearance between the plunger and sleeve of 0.0001 inch the leakage amounts to approximately 0.2 percent of the fuel injected with gasoline and as low as 0.01 percent with diesel fuel oils. With this mean clearance an effective seal is obtained when the length of the lap is three times the diameter of the lap. The deformation of the sleeve and plunger under pressure is sufficient to change the rate of leakage appreciably from that which would be obtained if the clearance was constant under pressure.

  14. Leakage current measurement in transformerless PV inverters

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Sera, Dezso; Mathe, Laszlo

    2012-01-01

    Photovoltaic (PV) installations have seen a huge increase during the last couple of years. Transformerless PV inverters are gaining more share of the total inverter market, due to their high conversion efficiency, small weight and size. Nevertheless safety should have an important role in case...... of these tranformerless systems, due to the missing galvanic isolation. Leakage and fault current measurement is a key issue for these inverter topologies to be able to comply with the required safety standards. This article presents the test results of two different current measurement sensors that were suggested...... to be used in commercial PV inverters for the measurement of leakage and fault ground currents. The German VDE0126–1–1 standard gives the limit for fault and leakage ground currents and all grid connected PV inverters have to comply with these limits and disconnect from the grid in case of a fault....

  15. Bulgarian Emergency Response System (BERS) in case of nuclear accident with exposure doses’estimation

    Energy Technology Data Exchange (ETDEWEB)

    Syrakov, M.; Prodanova, M.; Slavov, K.; Veleva, B.

    2015-07-01

    A PC-oriented Emergency Response System in case of nuclear accident (BERS) is developed and works operationally in the National Institute of Meteorology and Hydrology (NIMH). The creation and development of BERS was highly stimulated by the ETEX (European Tracer Experiment) project. BERS comprises two main parts - the operational and the accidental ones. The operational part, run automatically every 12 hours, prepares the input meteorological file used by both trajectory and dispersion models, runs the trajectory models, visualizes the results and uploads the maps of trajectories to a dedicated web-site. The accidental part is activated manually when a real radioactive releases occur or during emergency exercises. Its core is the Bulgarian dispersion models EMAP. Outputs are concentration, accumulated deposition and selected doses fields. In the paper, the BERS overall structure is described and examples of its products are presented. (Author)

  16. Study on radioactive fallout from Fukushima nuclear accident by plant samples using an imaging plate system

    International Nuclear Information System (INIS)

    Minowa, Haruka

    2011-01-01

    The radioactive fallout from the Fukushima nuclear accident was investigated by the radiation images of plant samples using an Imaging Plate System. Plant samples exposed by an imaging plate BASIII 2040 (Fujifilm, Japan) in overnight to one week, and radiation images were read by Typhoon FLA7000 (GE Healthcare Japan Corp.). Identifying and quantitative analysis of radionuclides were measured by Auto Well Gamma System ARC-380CL (Aloha Co. Ltd., Tokyo, Japan). In the cross-sectional images of the bamboo shoot, the radioactive material is shown in heterogeneous distribution, it was found that it concentrated on the tip of the edible portion, and thin skin. These radionuclides were identified as 137 Cs, 134 Cs, and 40 K. 40 K is a natural radionuclide, on the other hand 137 Cs and 134 Cs would be derived from the accident of the Fukushima Daiichi Nuclear Power Plant. A high concentration of 134 Cs was shown at the distance of 150 mm from the base of the bamboo shoot by cross-sectional cutting into the width of about 1 mm. It was estimated about 1 kBq of 134 Cs would be included in about 400 g (wet weight) of this one bamboo shoot in an edible part. Imaging data suggests that the contamination of radioactive cesium in this bamboo shoot was caused not by the extraneous attachment but by the absorption from roots. Because bamboo is gather water from extensive area, bamboo shoot concentrates the radioactive material contained in the rain even at low concentrations of radioactive materials in soil. (author)

  17. Solving the problem of valve stem leakage

    International Nuclear Information System (INIS)

    Dixon, D.F.

    1976-01-01

    Engineering solutions to valve stem leakage, in systems carrying expensive heavy water under pressure, have progressed from changing packing brands (failure) to leak collection (partial success) to elimination of small packed valves and an improved valve packing strategy involving stable packing materials, live Belleville spring-loading of packing, and issuance of a detailed stuffing box specification (success). (E.C.B.)

  18. Valve packing leakage monitoring device

    International Nuclear Information System (INIS)

    Ezekoye, L.I.

    1985-01-01

    A device for monitoring leakage of fluid across a seal in a component connected to a pressurized fluid system including a housing having a chamber with an inlet for receiving fluid leaking across the seal and an outlet. A positioning means is connected to an orifice plug so as to move the plug for permitting the fluid to be discharged through the orifice at the same rate at which it enters the first chamber and means for detecting the movement of the plug is provided to produce and output signal corresponding to the distance moved by the plug and thereby indicate flow rate. The positioning means compromise a piston attached to the plug by a hollow tube and springs, which at low flow rates locate the piston. When flow increases sufficiently pressure increases and urges the piston upwards. A magnetic portion of tube actuates a succession of proximity switches to indicate flow rate. (author)

  19. Particle and radiation leakage importance: definition, analysis, and interpretation

    International Nuclear Information System (INIS)

    Cacuci, D.G.; Wagschal, J.J.; Yaari, A.

    1982-01-01

    The concept of leakage importance function has been introduced and analyzed for physical systems governed by the Boltzmann transport equation. This leakage importance function represents a measure of the relative importance of source particles located at every point in phase space in contributing to the leakage and provides insight regarding the specific physical process that leads to leakage. The equation satisfied by the leakage importance function has been derived by using adjoint operators. It has been shown that procedures that are customarily used to derive an equation obeyed by an importance function suitable for an integral parameter such as a detector response or an eigenvalue lead to difficulties when directly applied to derive an equation obeyed by the leakage importance function. This is because, although leakage is also an integral parameter (i.e., a functional of the forward flux density), leakage is expressed in terms of a surface integral rather than in terms of volume integrals such as those appearing in expressions of detector responses or eigenvalues. Therefore, a procedure that departs from the customary course has been devised to derive the equation satisfied by the leakage importance function

  20. The collection and interpretation of domestic accident data. A discussion on some aspects of the British consumer safety system.

    Science.gov (United States)

    Wilson, J R

    1979-06-01

    This article discusses the workings of a Consumer Safety System and identifies the problems of collecting and using domestic accident data. In the light of proposed changes in the civil law on product liability, particular consideration is given to the difficulties of providing evidence of consumer product involvement in domestic accidents. The paper is based on one read at the CBI Conference "Product Liability in Perspective", held at the Hilton Hotel, London, 30-31 March, 1977. The views expressed are those of the Institute for Consumer Ergonomics and are not necessarily those of the Department of Prices and Consumer Protection.

  1. RASCAL [Radiological Assessment System for Consequence AnaLysis]: A screening model for estimating doses from radiological accidents

    International Nuclear Information System (INIS)

    Sjoreen, A.L.; Athey, G.F.; Sakenas, C.A.; McKenna, T.J.

    1988-01-01

    The Radiological Assessment System for Consequence AnaLysis (RASCAL) is a new MS-DOS-based dose assessment model which has been written for the US Nuclear Regulatory Commission for use during response to radiological emergencies. RASCAL is designed to provide crude estimates of the effects of an accident while the accident is in progress and only limited information is available. It has been designed to be very simple to use and to run quickly. RASCAL is unique in that it estimates the source term based on fundamental plant conditions and does not rely solely on release rate estimation (e.g., Ci/sec of I-131). Therefore, it can estimate consequences of accidents involving unmonitored pathways or projected failures. RASCAL will replace the older model, IRDAM. 6 refs

  2. An international intercomparison of national network systems used to provide early warning of a nuclear accident having transboundary implications

    DEFF Research Database (Denmark)

    Thompson, I.M.G.; Andersen, C.E.; Bøtter-Jensen, L.

    2000-01-01

    Since the Chernobyl accident many countries now operate large national networks of radiation detectors that continuously monitor radiation levels in order to give early warning of nuclear accidents having transboundary implications. The networks are used to provide data to assist in determining...... of these detectors are used. During an accident the data produced by such systems will be exchanged between countries within the European Communities, (EC) and as required by the IAEA's Early Warning Convention between the rest of the world and Europe. It is therefore important to ensure that such data should...... be harmonised so that it can be accurately interpreted by other countries and by international organisations. To assist with such harmonisation an intercomparison was held during May/June 1999 at the Riso Natural Environmental Radiation Measurement Station in Denmark and at the PTB underground laboratory...

  3. On the scaling of gas leakage from static seals

    International Nuclear Information System (INIS)

    Chivers, T.C.; Hunt, R.P.

    1977-01-01

    The interaction between gas leakage from static seals and eight potential variables is discussed. From a consideration of the interaction of these various parameters and the mechanical design of the seal system the importance of correctly interpreting leakage data is demonstrated. Given a situation where model experiments are necessary, this document forms a basis for the definition and interpretation of a test programme. (author)

  4. Emergency Response System for Pollution Accidents in Chemical Industrial Parks, China

    Directory of Open Access Journals (Sweden)

    Weili Duan

    2015-07-01

    Full Text Available In addition to property damage and loss of lives, environment pollution, such as water pollution and air pollution caused by accidents in chemical industrial parks (CIPs is a significant issue in China. An emergency response system (ERS was therefore planned to properly and proactively cope with safety incidents including fire and explosions occurring in the CIPs in this study. Using a scenario analysis, the stages of emergency response were divided into three levels, after introducing the domino effect, and fundamental requirements of ERS design were confirmed. The framework of ERS was composed mainly of a monitoring system, an emergency command center, an action system, and a supporting system. On this basis, six main emergency rescue steps containing alarm receipt, emergency evaluation, launched corresponding emergency plans, emergency rescue actions, emergency recovery, and result evaluation and feedback were determined. Finally, an example from the XiaoHu Chemical Industrial Park (XHCIP was presented to check on the integrality, reliability, and maneuverability of the ERS, and the result of the first emergency drill with this ERS indicated that the developed ERS can reduce delays, improve usage efficiency of resources, and raise emergency rescue efficiency.

  5. Lessons learned from the Fukushima accident to improve the performance of the national nuclear preparedness system

    International Nuclear Information System (INIS)

    Dewi Apriliani

    2013-01-01

    A study of emergency response failure in the early phase of a nuclear accident in Fukushima, Japan has conducted. This study aimed to obtain lesson learned from the problems and constraints that exist at the time of the Fukushima emergency response. This lesson learned will be adjusted to the situation, conditions and problems in nuclear preparedness systems in Indonesia, so that it can obtain the necessary recommendations to improve the performance of SKNN (National Nuclear Emergency Preparedness System). Recommendations include: improvements in coordination and information systems, including early warning systems and dissemination of information; improvements in the preparation of emergency plans/contingency plan, which includes an integrated disaster management; improvement in the development of disaster management practice/field exercise, by extending the scenario and integrate it with nuclear disaster, chemical, biological, and acts of terrorism; and improvement in public education of nuclear emergency preparedness and also improvement in management for dissemination of information to the public and the mass media. These improvements need to be done as part of efforts in preparing a reliable nuclear emergency preparedness in order to support nuclear power plant development plan. (author)

  6. Emergency Response System for Pollution Accidents in Chemical Industrial Parks, China.

    Science.gov (United States)

    Duan, Weili; He, Bin

    2015-07-10

    In addition to property damage and loss of lives, environment pollution, such as water pollution and air pollution caused by accidents in chemical industrial parks (CIPs) is a significant issue in China. An emergency response system (ERS) was therefore planned to properly and proactively cope with safety incidents including fire and explosions occurring in the CIPs in this study. Using a scenario analysis, the stages of emergency response were divided into three levels, after introducing the domino effect, and fundamental requirements of ERS design were confirmed. The framework of ERS was composed mainly of a monitoring system, an emergency command center, an action system, and a supporting system. On this basis, six main emergency rescue steps containing alarm receipt, emergency evaluation, launched corresponding emergency plans, emergency rescue actions, emergency recovery, and result evaluation and feedback were determined. Finally, an example from the XiaoHu Chemical Industrial Park (XHCIP) was presented to check on the integrality, reliability, and maneuverability of the ERS, and the result of the first emergency drill with this ERS indicated that the developed ERS can reduce delays, improve usage efficiency of resources, and raise emergency rescue efficiency.

  7. Generating a 3D Simulation of a Car Accident from a Formal Description : the CarSim System

    NARCIS (Netherlands)

    Egges, A.; Nijholt, A.; Nugues, P.

    2001-01-01

    The problem of generating a 3D simulation of a car accident from a written description can be divided into two subtasks: the linguistic analysis and the virtual scene generation. As a means of communication between these two system parts, we designed a template formalism to represent a written

  8. Design implementation of the post-accident monitoring (PAM) system for Wolsong NPP Units 2, 3 and 4 in Korea

    International Nuclear Information System (INIS)

    Sang Joon Han

    1995-01-01

    This paper is intended to introduce the actual design implementation of the post-accident monitoring system and to provide a good opportunity to understand what issue items are at the design implementation stage for Wolsong 2, 3 and 4. 3 refs, 3 tabs

  9. Leakage radiation spectroscopy of organic/dielectric/metal systems: influence of SiO2 on exciton-surface plasmon polariton interaction

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Kawalec, Tomasz; Kostiučenko, Oksana

    side of a hemisphere fused silica prism with an index matching liquid was illuminated under normal incidence by a He-Cd 325 nm laser. Two orthogonal linear polarizations were used both parallel and perpendicular to the detection plane. Spectrally resolved leakage radiation was observed on the opposite...... side of the Ag film (i.e. at the hemisphere prism) as a function of the scattering angle. Each spectrum contains a distinct peak at a wavelength dependent angle above the critical angle. This way the dispersion curve was measured, originating from a hybrid mode, i.e. the interaction between the p-6P...... excitons and surface plasmon polaritons (SPPs) of the metal/dielectric boundary. The presence of the SiO2 layer considerably changes the dispersion curve in comparison to the one of the Ag/p-6P/air system. However, the Ag/SiO2/p-6P/air stack forms a stable structure allowing construction of organic...

  10. Electrical Systems at Laguna Verde Nuclear Power Plant (LVNPP) after the Fukushima accident

    International Nuclear Information System (INIS)

    Lopez Jimenez, Jose Francisco

    2015-01-01

    During the accident occurred in Fukushima Daiichi Nuclear Power Station in Japan, the onsite and offsite electrical systems were affected and lost for a long time with irreversible consequences, therefore, the Mexican Regulatory Body known as the National Commission for Nuclear Safety and Safeguards (CNSNS: for its acronym in Spanish) has taken several actions to review the current capacity of the electrical systems installed at Laguna Verde NPP to cope with an event beyond of the design basis. The first action was to require to Laguna Verde NPP the compliance with Information Notice 2011-05 'Tohoku-Taiheiyou-Oki earthquake effects on Japanese Nuclear Power Plants' and with 10 CFR 50.54 'Conditions of licenses' section 'hh', both documents were issued by the United States Nuclear Regulatory Commission (USNRC). Additionally, CNSNS has taken into account the response actions emitted by other countries after the Fukushima accident. This involved the review of documents generated by Germany, Canada, United Arab Emirates, Finland, France, the United Kingdom and the Western European Nuclear Regulator's Association (WENRA). CNSNS made special inspections to verify the current capacity of the electrical systems of AC and DC. As a result of these inspections, CNSNS issued requirements that must be addressed by Laguna Verde NPP to demonstrate that it has the capacity to cope with events beyond the design basis. Parallel to the above, Mexico has participated in the Ibero-american Forum to address matters related to the 'Resistance Tests', the evaluations of the Forum have reached similar conclusions to those required by European Nuclear Safety Regulators Group (ENSREG), under the format proposed by WENRA. The actions carried out here are closely linked to the requirements established by the USNRC. It is also important to mention that: 1) the Extended Power Up-rate project was implemented in both Units of the Laguna Verde NPP before

  11. Treatment of sodium spills and leakage detection at loop-type fast reactors

    International Nuclear Information System (INIS)

    Foerster, K.; Fortmann, M.; Lang, H.; Moellerfeld, H.

    1979-01-01

    Sodium spills are of great importance in the safety analysis for sodium cooled nuclear plants. Large leakages can lead to a depletion of the heat transfer system and cause the loss of cooling of the reactor. Further the hot sodium may attack structural materials. In areas with air atmosphere large amounts of sodium can burn and cause great damages. Therefore the control of large leakages is an indispensable task in design and construction of sodium cooled reactor systems. Because of the typical arrangement of widespread long pipe systems loop type plants are subject to a gradually greater risk of damage than pool type plants. The sodium catching devices of the SNR-300 are described and their function is illustrated as an example for the treatment of large spills. Since the equipment for the control of large amounts of leaking sodium is very expensive, great efforts are made in order to save costs and to decrease safety problems. It is aimed to minimize the probability of such events to a degree that they no longer are to be considered realistic. The advantageous operating conditions and the favourable material properties support this aim. Under the well known keyword 'leak-before-rupture' criterion this task is pursued. Crack growth measurements are made at structural materials under LMFBR conditions, and leakage detecting systems are being developed. Some test results concerning this task are described. Despite the fact that there are good chances to verify the leak-before-rupture criterion it is assumed that certain hypothetical accidents occur, which are to be considered in the design of the reactor plant. The extremely improbable Bethe-Tait-accident (HCDA) is such an event. It would lead to a super spill, that means to the complete depletion of the reactor tank. For the SNR-300 plant a system is provided that is able to catch this super spill and the core melt. This core catcher must withstand the high temperatures and remove the decay heat. The purpose of this

  12. Passive system for cooling the inboard region in case of a severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Boccaccini, L.V. E-mail: lorenzo.boccaccini@irs.fzk.de; Gordeev, S.; Malang, S

    2002-12-01

    Previous calculations performed for different fusion reactor concepts indicated that the absence of an effective heat sink for the after-heat in the inboard region can cause concerns for the temperatures reached in case of a severe accident. This can compromise the mechanical stability of the vacuum vessel (VV) or cause unacceptable temperatures of the inboard in-vessel components with consequence in the overall safety strategy. This paper describes a design solution that has been proposed for the European Helium Cooled Solid Breeder Reactor that allows transporting the heat from the inboard to the outboard side with a passive cooling system located in the VV and based on natural circulation of liquid lead. The presented calculations aim to demonstrate the feasibility and effectiveness of such a system. The presented results have been obtained for a geometry and parameters based on a particular reactor, nevertheless the system can be adopted for a large variety of reactor concepts being relatively independent of a particular blanket or maintenance schema.

  13. SSYST. A code system to analyze LWR fuel rod behavior under accident conditions

    International Nuclear Information System (INIS)

    Gulden, W.; Meyder, R.; Borgwaldt, H.

    1982-01-01

    SSYST (Safety SYSTem) is a modular system to analyze the behavior of light water reactor fuel rods and fuel rod simulators under accident conditions. It has been developed in close cooperation between Kernforschungszentrum Karlsruhe (KfK) and the Institut fuer Kerntechnik und Energiewandlung (IKE), University Stuttgart, under contract of Projekt Nukleare Sicherheit (PNS) at KfK. Although originally aimed at single rod analysis, features are available to calculate effects such as blockage ratios of bundles and wholes cores. A number of inpile and out-of-pile experiments were used to assess the system. Main differences versus codes like FRAP-T with similar applications are (1) an open-ended modular code organisation, (2) availability of modules of different sophistication levels for the same physical processes, and (3) a preference for simple models, wherever possible. The first feature makes SSYST a very flexible tool, easily adapted to changing requirements; the second enables the user to select computational models adequate to the significance of the physical process. This leads together with the third feature to short execution times. The analysis of transient rod behavior under LOCA boundary conditions e.g. takes 2 mins cpu-time (IBM-3033), so that extensive parametric studies become possible

  14. Analysis of loss of coolant accident and emergency core cooling system

    International Nuclear Information System (INIS)

    Abe, Kiyoharu; Kobayashi, Kenji; Hayata, Kunihisa; Tasaka, Kanji; Shiba, Masayoshi

    1977-01-01

    In this paper, the analysis for the performance evaluation of emergency core cooling system is described, which is the safety protection device to the loss of coolant accidents due to the break of primary cooling pipings of light water reactors. In the LOCA analysis for the performance evaluation of ECCS, it must be shown that a reactor core keeps the form which can be cooled with the ECCS in case of LOCA, and the overheat of the core can be prevented. Namely, the shattering of fuel cladding tubes is never to occur, and for the purpose, the maximum temperature of Zircaloy 2 or 4 cladding tubes must be limited to 1200 deg C, and the relative thickness of oxide film must be below 15%. The calculation for determining the temperature of cladding tubes in case of the LOCA in BWRs and PWRs is explained. First, the primary cooling system, the ECCS and the related installations of BWRs and PWRs are outlined. The code systems for LOCA/ECCS analysis are divid ed into several steps, such as blowdown process, reflooding process and heatup calculation. The examples of the sensitivity analysis of the codes are shown. The LOCA experiments carried out so far in Japan and foreign countries and the LOCA analysis of a BWR with RELAP-4J code are described. The guidance for the performance evaluation of ECCS was established in 1975 by the Reactor Safety Deliberation Committee in Japan, and the contents are quoted. (Kako, I.)

  15. Interfacing systems LOCAs [Loss of Coolant Accidents] at boiling water reactors

    International Nuclear Information System (INIS)

    Chu, Tsong-Lun; Fitzpatrick, R.; Stoyanov, S.

    1987-01-01

    The work presented in this paper was performed by Brookhaven National Laboratory (BNL) in support of Nuclear Regulatory Commission's (NRC) effort towards the resolution of Generic Issue 105 ''Interfacing System Loss of Coolant Accidents (LOCAs) at Boiling Water Reactors (BWRs).'' For BWRs, intersystem LOCA have typically either not been considered in probabilistic risk analyses, or if considered, were judged to contribute little to the risk estimates because of their perceived low frequency of occurrence. However, recent operating experience indicates that the pressure isolation valves (PIVs) in BWRs may not adequately protect against overpressurization of low pressure systems. The objective of this paper is to present the results of a study which analyzed interfacing system LOCA at several BWRs. The BWRs were selected to best represent a spectrum of BWRs in service using industry operating event experience and plant-specific information/configurations. The results presented here include some possible changes in test requirements/practices as well as an evaluation of their reduction potential in terms of core damage frequency

  16. Diagnostic performance of a CT-based scoring system for diagnosis of anastomotic leakage after esophagectomy: comparison with subjective CT assessment

    Energy Technology Data Exchange (ETDEWEB)

    Goense, Lucas; Rossum, Peter S.N. van [University Medical Center Utrecht, Department of Surgery, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiation Oncology, Utrecht (Netherlands); Stassen, Pauline M.C.; Ruurda, Jelle P.; Hillegersberg, Richard van [University Medical Center Utrecht, Department of Surgery, Utrecht (Netherlands); Wessels, Frank J.; Leeuwen, Maarten S. van [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands)

    2017-10-15

    To develop a CT-based prediction score for anastomotic leakage after esophagectomy and compare it to subjective CT interpretation. Consecutive patients who underwent a CT scan for a clinical suspicion of anastomotic leakage after esophagectomy with cervical anastomosis between 2003 and 2014 were analyzed. The CT scans were systematically re-evaluated by two radiologists for the presence of specific CT findings and presence of an anastomotic leak. Also, the original CT interpretations were acquired. These results were compared to patients with and without a clinical confirmed leak. Out of 122 patients that underwent CT for a clinical suspicion of anastomotic leakage; 54 had a confirmed leak. In multivariable analysis, anastomotic leakage was associated with mediastinal fluid (OR = 3.4), esophagogastric wall discontinuity (OR = 4.9), mediastinal air (OR = 6.6), and a fistula (OR = 7.2). Based on these criteria, a prediction score was developed resulting in an area-under-the-curve (AUC) of 0.86, sensitivity of 80%, and specificity of 84%. The original interpretation and the systematic subjective CT assessment by two radiologists resulted in AUCs of 0.68 and 0.75 with sensitivities of 52% and 69%, and specificities of 84% and 82%, respectively. This CT-based score may provide improved diagnostic performance for diagnosis of anastomotic leakage after esophagectomy. (orig.)

  17. Assessment of passive safety system performance under main steam line break accident

    International Nuclear Information System (INIS)

    Lim, J.; Choi, S.W.; Yang, J.; Lee, D.Y.; Rassame, S.; Hibiki, T.; Ishii, M.

    2014-01-01

    Highlights: • An integral test of MSLB was conducted in a small-scale test facility, i.e. PUMA which is scaled to generation III + BWR applications. • GDCS as an ECCS provided adequate supply of water to keep RPV coolant level well above TAF. • PCCS kept containment below design pressure during long-term cooling phase. - Abstract: A generation III + Boiling Water Reactor (BWR) which relies on natural circulation has evolved from earlier BWR designs by incorporating passive safety features which require no emergency injection pump and no operator action or Alternating Current (AC) power supply. The generation III + BWR’s passive safety systems include the Automatic Depressurization System (ADS), the Suppression Pool (SP), the Standby Liquid Control System (SLCS), the Gravity Driven Cooling System (GDCS), the Isolation Condenser System (ICS), and the Passive Containment Cooling System (PCCS). The ADS is actuated to rapidly depressurize the reactor leading to the GDCS injection. The large amount of water in the SP condenses steam from the reactor. The SLCS provides makeup water to the reactor. The GDCS injects water into the reactor by gravity head and provides cooling to the core. The ICS and the PCCS are used to remove the decay heat from the reactor. The objective of this paper is to analyze the response of passive safety systems under the Loss of Coolant Accident (LOCA). A Main Steam Line Break (MSLB) test has been conducted in the Purdue University Multi-Dimensional Integral Test Assembly (PUMA) which is scaled to represent the generation III + BWR. The main results of PUMA MSLB test were that the reactor coolant level was well above the Top of Active Fuel (TAF) and the reactor containment pressure has remained below the design pressure. In particular, the minimum water level (1.706 m) was 5% higher than the TAF (1.623 m) and the containment maximum pressure (271 kPa) was 35% lower than the safety limit (414 kPa), respectively

  18. Thermal-hydraulic analysis for changing feedwater check valve leakage rate testing methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.; Harrell, J.

    1996-12-01

    The current design and testing requirements for the feedwater check valves (FWCVs) at the Grand Gulf Nuclear Station are established from original licensing requirements that necessitate extremely restrictive air testing with tight allowable leakage limits. As a direct result of these requirements, the original high endurance hard seats in the FWCVs were modified with elastomeric seals to provide a sealing surface capable of meeting the stringent air leakage limits. However, due to the relatively short functional life of the elastomeric seals compared to the hard seats, the overall reliability of the sealing function actually decreased. This degraded performance was exhibited by frequent seal failures and subsequent valve repairs. The original requirements were based on limited analysis and the belief that all of the high energy feedwater vaporized during the LOCA blowdown. These phenomena would have resulted in completely voided feedwater lines and thus a steam environment within the feedwater leak pathway. To challenge these criteria, a comprehensive design basis accident analysis was developed using the RELAP5/MOD3.1 thermal-hydraulic code. Realistic assumptions were used to more accurately model the post-accident fluid conditions within the feedwater system. The results of this analysis demonstrated that no leak path exists through the feedwater lines during the reactor blowdown phase and that sufficient subcooled water remains in various portions of the feedwater piping to form liquid water loop seals that effectively isolate this leak path. These results provided the bases for changing the leak testing requirements of the FWCVs from air to water. The analysis results also established more accurate allowable leakage limits, determined the real effective margins associated with the FWCV safety functions, and led to design changes that improved the overall functional performance of the valves.

  19. 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

  20. 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

  1. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  2. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  3. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  4. Aid system in the attention direction for accidents diagnosis at nuclear power plants based on artificial intelligence

    International Nuclear Information System (INIS)

    Costa, Rafael Gomes da

    2009-01-01

    Transient identification in Nuclear Power Plant (NPP) is often a very hard task and may involve a great amount of human cognition. The early identification of unexpected departures from steady state behavior is an essential step for the operation, control and accident management in NPPs. The bases for the transient identification relay on the evidence that different system faults and anomalies lead to different pattern evolution in the involved process variables. During an abnormal event, the operator must monitor a great amount of information from the instruments that represents a specific type of event Several systems based on specialist systems, neural-networks, and fuzzy logic have been developed for transient identification. In the work, we investigate the possibility of using a Neuro Fuzzy modeling tool for efficient transient identification, aiming to helping the operator crew to take decisions relative to the procedure to be followed in situations of accidents/transients at NPPs. The proposed system uses artificial neural networks (ANN) as first level transient diagnostic After the ANN has done the preliminary transient type identification, a fuzzy-logic system analyzes the results emitting reliability degree of it. A preliminary evaluation of the developed system was made at the Human-System Interface Laboratory (LABIHS). The obtained results show that the system can help the operators to take decisions during transients/accidents in the plant (author)

  5. Design of environment monitoring system to evaluate radionuclide release from subsystem on PWR nuclear power accident

    International Nuclear Information System (INIS)

    Sri Kuntjoro; Sugiyanto; Pande Made Udiyani; Jupiter Sitorus Pane

    2012-01-01

    Nuclear Power Plan (NPP) as a renewable energy source is selected as an alternative, because it has many advantages that is environmentally friendly, fuel supply which is independent of the season, and the price that can compete with other power plants. However, the existence of some public skepticism about nuclear radiation safety, the government must be convinced about the operation of nuclear power plants are safe and secure. Research on the design of environment monitoring system for evaluation of radionuclide release from the reactor subsystems and the environment due to accidents at power reactors has been done. The study was conducted by calculating the distribution of radionuclide release into the reactor subsystem and the environment and also to build the environment radiation monitoring system. Environmental monitoring system consists of a radiation counter, early warning systems, meteorological measurement systems, GPS systems and GIS. Radiation monitoring system used to record the data of radiation, meteorological measurement system used to record data of wind and speed direction, while the GPS system is used to determine position of data measurements. The data is then transmitted to a data acquisition system and then to be transmitted to the control center. Collection and transmission of data is done via SMS formatting using a modem device that is placed in the control center. The control center receives measurement data from various places. In this case the control center has a function as an SMS Gateway. This system can visualize for different measurement locations. Furthermore, radiation data and position data to be integrated with digital maps. System integration is then visualized in a personal computer. To position of measurements directly visualized on the map and also look for the data displayed on a monitor as a red or green circle colour. That colour indicated as a safe limit of radiation monitor. When the cycle colour is red, the system will

  6. An approach to build a knowledge base for reactor accident diagnostic expert system

    International Nuclear Information System (INIS)

    Yoshida, K.; Fujii, M.; Fujiki, K.; Yokobayashi, M.; Kohsaka, A.; Aoyagi, T.; Hirota, Y.

    1987-01-01

    In the development of a rule based expert system, one of the key issues is how to acquire knowledge and to build knowledge base (KB). On building the KB of DISKET, which is an expert system for nuclear reactor accident diagnosis developed in JAERI, several problems have been experienced as follows. To write rules is a time consuming task, and it is difficult to keep the objectivity and consistency of rules as the number of rules increase. Further, certainty factors (CFs) must be often determined according to engineering judgment, i.e., empirically or intuitively. A systematic approach was attempted to handle these difficulties and to build an objective KB efficiently. The approach described in this paper is based on the concept that a prototype KB, colloquially speaking an initial guess, should first be generated in a systematic way and then is to be modified and/or improved by human experts for practical use. Statistical methods, principally Factor Analysis, were used as the systematic way to build a prototype KB for the DISKET using a PWR plant simulator data. The source information is a number of data obtained from the simulation of transients, such as the status of components and annunciator etc., and major process parameters like pressures, temperatures and so on

  7. Radiation Accident Dosimetry System Based on Chemical Dosimetry and an Optoelectronic Reader

    International Nuclear Information System (INIS)

    Ilijas, B.; Razem, D.; Miljanic, S.; Cerovac, Z.; Orehovec, Z.

    2003-01-01

    There are many potential sources of mass irradiation in today's world. Threats of a classic nuclear encounter or of an accident of some nuclear facility are now accompanied with a real possibility of nuclear terrorism, in context of which a threat of radiological emergency is very probable. Mass irradiation and radiological contamination of large areas and structures pose great problems to medical and emergency staff in the peacetime or to army troops in a war. The only reliable and sufficiently rapidly accessible data about the dose absorbed by any person can be achieved by means of personal dosimetry. These data are of the utmost importance for medical treatment and triage, as well as for determining the capability of military troops. Personal dosimetry system for this purpose must fulfill some specific requirements on reliability, dose range and cost. Chemical radiation dosimetry system based on the chemical CET dosimeter and an optoelectronic reader is designed primarily for this purpose. Its characteristics are, among others, nearly equal sensitivity to gamma and neutron irradiation, dose range between 0.2 and 14.0 Gy, the possibility of electronic processing of data and a low cost. It is intended for a large number of persons and therefore can give enough data for statistical analysis, yet the separate data for any single person can give a reliable basis for the individual medical treatment. The possibility of connection with a PC enables the formation of large data bases for further processing and analysis. (author)

  8. Leakage monitoring device and method

    International Nuclear Information System (INIS)

    Yamada, Izumi; Matsui, Yuji; Fujimori, Haruo.

    1995-01-01

    In a water leakage monitor for a steam generator, output signals from an acoustic sensor disposed in the vicinity of a region to be monitored is subjected to phasing calculation (beam forming calculation) to determine the distribution of a sound source intensity distribution. A peak is retrieved based on the distribution of the sound source intensity distribution. A correction coefficient depending on the position of the peak is multiplied to the sound source intensity. The presence or absence of leakage is determined based on the degree of the sound source intensity after the completion of correction. Namely, a relative value of sound source intensity for each of the portions in the region to be monitored is determined, and the point of the greatest sound source intensity is assumed as a leaking point, to determine the position of the leakage. An absolute value of the sound source intensity at the leaking point is determined by such a constitution that a correction coefficient depending on the position is multiplied to the intensity of the position of the peak in the distribution of the sound intensity. A threshold value for the determination of the presence or absence of the leakage can be set if a relation between an amount of the leakage previously determined experimentally and the intensity of the sound source. Then, a countermeasure can easily be taken after the detection of the leakage and a restoring operation can be carried out rapidly after the occurrence of leakage while avoiding unnecessary shutdown. (N.H.)

  9. Lessons learnt from an international intercomparison of national network systems used to provide early warning of a nuclear accident

    DEFF Research Database (Denmark)

    Saez-Vergara, J.C.; Thompson, I.M.G.; Funck, E.

    2003-01-01

    and at the Underground Laboratory for Dosimetry and Spectrometry (UDO) of the Physikalisch-Technische Bundesanstalt (PTB) in Germany. The network systems are used continuously to monitor radiation levels throughout a country in order to give early warning of nuclear accidents having transboundary implications......As part of the European Research Council's Fourth Framework Programme, the EURADOS Action Group on Monitoring of External Exposures held an intercomparison of national network systems. This took place during May/June 1999 at the Riso Natural Environmental Radiation Measurement Station in Denmark....... The radiation levels measured are used to estimate the radiation risks to people arising from the accident. Seven European countries participated in the intercomparison with detector systems used in their national network systems as well as with detectors being developed for future use. Since different...

  10. Lessons learnt from an international intercomparison of national network systems used to provide early warning of a nuclear accident

    DEFF Research Database (Denmark)

    Saez-Vergara, J.C.; Thompson, I.M.G.; Funck, E.

    2003-01-01

    and at the Underground Laboratory for Dosimetry and Spectrometry (UDO) of the Physikalisch-Technische Bundesanstalt (PTB) in Germany. The network systems are used continuously to monitor radiation levels throughout a country in order to give early warning of nuclear accidents having transboundary implications....... The radiation levels measured are used to estimate the radiation risks to people arising from the accident. Seven European countries participated in the intercomparison with detector systems used in their national network systems as well as with detectors being developed for future use. Since different...... radiation quantities were measured by the systems (namely exposure, air kerma and ambient dose equivalent), the initial analysis of the intercomparison results was made in terms of the quantity air kerma rate. This report completes the analysis of the results and these are given in terms of air kerma rate...

  11. Development of the simulation system {open_quotes}IMPACT{close_quotes} for analysis of nuclear power plant severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Naitoh, Masanori; Ujita, Hiroshi; Nagumo, Hiroichi [Nuclear Power Corp. (Japan)] [and others

    1997-07-01

    The Nuclear Power Engineering Corporation (NUPEC) has initiated a long-term program to develop the simulation system {open_quotes}IMPACT{close_quotes} for analysis of hypothetical severe accidents in nuclear power plants. IMPACT employs advanced methods of physical modeling and numerical computation, and can simulate a wide spectrum of senarios ranging from normal operation to hypothetical, beyond-design-basis-accident events. Designed as a large-scale system of interconnected, hierarchical modules, IMPACT`s distinguishing features include mechanistic models based on first principles and high speed simulation on parallel processing computers. The present plan is a ten-year program starting from 1993, consisting of the initial one-year of preparatory work followed by three technical phases: Phase-1 for development of a prototype system; Phase-2 for completion of the simulation system, incorporating new achievements from basic studies; and Phase-3 for refinement through extensive verification and validation against test results and available real plant data.

  12. Feasibility study of tank leakage mitigation using subsurface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F. [Ensearch Environmental, Inc. (United States); Rouse, J.K.; McLaughlin, T.J. [Bovay Northwest, Inc., Richland, WA (United States); Cruse, J.M. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-09-21

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report.

  13. Feasibility study of tank leakage mitigation using subsurface barriers

    International Nuclear Information System (INIS)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F.; Rouse, J.K.; McLaughlin, T.J.; Cruse, J.M.

    1994-01-01

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report

  14. Whole-Pin Furnace system: An experimental facility for studying irradiated fuel pin behavior under potential reactor accident conditions

    International Nuclear Information System (INIS)

    Liu, Y.Y.; Tsai, H.C.; Donahue, D.A.; Pushis, D.O.; Savoie, F.E.; Holland, J.W.; Wright, A.E.; August, C.; Bailey, J.L.; Patterson, D.R.

    1990-05-01

    The whole-pin furnace system is a new in-cell experimental facility constructed to investigate how irradiated fuel pins may fail under potential reactor accident conditions. Extensive checkouts have demonstrated excellent performance in remote operation, temperature control, pin breach detection, and fission gas handling. The system is currently being used in testing of EBIR-II-irradiated Integral Fast Reactor (IFR) metal fuel pins; future testing will include EBR-II-irradiated mixed-oxide fuel pins. 7 refs., 4 figs

  15. Analysis of the Civil Defence system and service of radiation-ecological safety in nuclear and chemical accidents

    International Nuclear Information System (INIS)

    1992-01-01

    System of Civil Defense (CD) and service of radiation-ecological safety of the population of Belarus in case of nuclear and chemical accidents are analysed. Shortcomings in CD system organization are marked. Recommendations on the removal of available shortcomings are given. Necessity of modern information techniques for continuous monitoring of hazards sources is shown as well as operative control of preventive and rescue actions

  16. Collaboration within the United Nations system - General matters. Conventions concerning nuclear accidents

    International Nuclear Information System (INIS)

    1988-03-01

    The texts of the Convention on Early Notification of a Nuclear Accident (CENNA) and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (CANARE) are preceded by brief remarks on their origin. The World Health Organization is bound to carry out the activities envisaged, by virtue or its constitutional responsibility for ''promoting, developing, assisting and coordinating international health work''. The Executive Board thus recommends that the WHO accede to both conventions

  17. An intelligent support system for automatic detection of cerebral vascular accidents from brain CT images.

    Science.gov (United States)

    Hajimani, Elmira; Ruano, M G; Ruano, A E

    2017-07-01

    This paper presents a Radial Basis Functions Neural Network (RBFNN) based detection system, for automatic identification of Cerebral Vascular Accidents (CVA) through analysis of Computed Tomographic (CT) images. For the design of a neural network classifier, a Multi Objective Genetic Algorithm (MOGA) framework is used to determine the architecture of the classifier, its corresponding parameters and input features by maximizing the classification precision, while ensuring generalization. This approach considers a large number of input features, comprising first and second order pixel intensity statistics, as well as symmetry/asymmetry information with respect to the ideal mid-sagittal line. Values of specificity of 98% and sensitivity of 98% were obtained, at pixel level, by an ensemble of non-dominated models generated by MOGA, in a set of 150 CT slices (1,867,602pixels), marked by a NeuroRadiologist. This approach also compares favorably at a lesion level with three other published solutions, in terms of specificity (86% compared with 84%), degree of coincidence of marked lesions (89% compared with 77%) and classification accuracy rate (96% compared with 88%). Copyright © 2017. Published by Elsevier B.V.

  18. A parametric study of MELCOR Accident Consequence Code System 2 (MACCS2) Input Values for the Predicted Health Effect

    International Nuclear Information System (INIS)

    Kim, So Ra; Min, Byung Il; Park, Ki Hyun; Yang, Byung Mo; Suh, Kyung Suk

    2016-01-01

    The MELCOR Accident Consequence Code System 2, MACCS2, has been the most widely used through the world among the off-site consequence analysis codes. MACCS2 code is used to estimate the radionuclide concentrations, radiological doses, health effects, and economic consequences that could result from the hypothetical nuclear accidents. Most of the MACCS model parameter values are defined by the user and those input parameters can make a significant impact on the output. A limited parametric study was performed to identify the relative importance of the values of each input parameters in determining the predicted early and latent health effects in MACCS2. These results would not be applicable to every case of the nuclear accidents, because only the limited calculation was performed with Kori-specific data. The endpoints of the assessment were early- and latent cancer-risk in the exposed population, therefore it might produce the different results with the parametric studies for other endpoints, such as contamination level, absorbed dose, and economic cost. Accident consequence assessment is important for decision making to minimize the health effect from radiation exposure, accordingly the sufficient parametric studies are required for the various endpoints and input parameters in further research

  19. Nuclear Accidents Archive Knowledge Organization System Portal “NAAKOS”: An Application of Semantic Technologies in the Nuclear Domain

    International Nuclear Information System (INIS)

    Atieh, T.

    2016-01-01

    Full text: In line with the IAEA Action Plan on Nuclear Safety, the IAEA was requested to assist Member States enhancing transparency and effectiveness of communication among operators, regulators and various international organizations, and supporting wide dissemination of safety related technical information on nuclear safety. In this context, the IAEA was further asked to analyse and preserve lessons learned from the Fukushima Daiichi NPP accident, as well as from past major incidents and radiological events. The IAEA NKM Section has launched the Nuclear Accidents Repository Portal Knowledge Organization System “NAAKOS” initiative which aims at collecting and preserving data, information, and knowledge related to nuclear accidents and making this knowledge available through one single access point, while ensuring their long term preservation. The NKM Section has developed the Nuclear Accidents Taxonomy which will be used, along other nuclear taxonomies, to enhance information retrieval. It would also include the use of semantic technologies, data mining and linked data to support users beyond the traditional search facilities. The overall objective is to assist to find predefined measures in a timely manner that could prevent, or at least minimize the adverse effects of incidents. (author

  20. Development of a decision support system for off-site emergency management in the early phase of a nuclear accident

    International Nuclear Information System (INIS)

    Datta, D.; Sharma, R.M.

    2002-01-01

    Full text: Experience gained after the Chernobyl accident clearly demonstrated the importance of improving administrative, organizational and technical emergency management arrangements in India. The more important areas where technical improvements were needed were early warning monitoring, communication networks for the rapid and reliable exchange of radiological and other information and decision support systems for off-site emergency management. A PC based artificial intelligent software has been developed to have a decision support system that can easily implement to manage off-site nuclear emergency and subsequently analyze the off-site consequences of the nuclear accident. A decision support tool, STEPS (source term estimate based on plant status), that provides desired input to the present software was developed. The tool STEPS facilitates meta knowledge of the system. The paper describes the details of the design of the software, functions of various modules, tuning of respective knowledge base and overall its scope in real sense in nuclear emergency preparedness and response

  1. Direct measurement of multi-noncondensable and steam mixture under an accident condition of a Passive Containment Cooling System (PCCS)

    International Nuclear Information System (INIS)

    Yokobori, S.; Arai, K.; Tobimatsu, T.; Kurita, T.; Ishizuka, T.; Oikawa, H.; Herzog, W.

    1998-01-01

    The Passive Containment Cooling System (PCCS) has a function to remove the long-term decay heat following an accident by condensation. As an extension of the PCCS development program, its heat removal capability under a severe accident condition has been tested. The effect of the lighter noncondensable than steam on the PCCS heat transfer characteristics was clarified. Helium gas was used to simulate hydrogen gas which can be generated by metal-water reaction. In the final stage, multi-noncondensables (i.e. both nitrogen and helium) were simultaneously confined. The GIRAFFE measurement system was accordingly modified so that noncondensable gas concentration was directly measured. Due to installation of direct measurement system of noncondensable, the noncondensable transport mechanism was modeled so that the analytical code might be remarkably improved. (author)

  2. 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

  3. Effect of RCIC Operating Conditions on the Accident Scenario in Fukushima Unit 2

    International Nuclear Information System (INIS)

    Kim, Sung Il; Park, Jong Hwa; Ha, Kwang Soon

    2015-01-01

    This study was conducted by using MELCOR 1.8.6. Fukushima unit 2 accident was analyzed using MELCOR in this study, and best estimate scenario with considering RCIC operating conditions was presented. Researches on the boiling water reactor (BWR) plant with reactor core isolation cooling (RCIC) system have been conducted. Research on the RCIC operation in Fukushima unit 2 was also conducted by Sandia National Laboratory. MELCOR analysis of the Fukushima unit 2 accident was conducted in the report and energy balance in wetwell was described by considering RCIC operation. However, the effect of RCIC operation condition on the accident scenario has not been studied. The operating conditions of RCIC system affect the pressures in wetwell and drywell, and the high pressure can make leakage path of fission product from PCV to reactor building. Thus it can be directly related with the amount of fission product which released to environment. In this study, severe accident on Fukushima unit 2 was analyzed considering the operating condition of RCIC system, and best estimated scenario was presented. In addition, the effect of RCIC turbine efficiency on the accident progression was examined. Energy balance in suppression chamber was also considered with discussion on the effect of torus room flooding level. It was found that the operating condition of RCIC turbine not only affects the variation of drywell pressure but also the amount of released fission products to environment. It was also confirmed that the RCIC turbine efficiency in the accident would be less than normal operating condition

  4. Methane leakage in natural gas operations

    International Nuclear Information System (INIS)

    Jennervik, A.

    1992-01-01

    The world gas industry is efficient in conservation of natural gas within its systems. As the influence of methane as an infra-red absorbent gas has been more widely recognized, the considerations of methane's greenhouse effect has become vitally important to gas companies around the world. The industry is universally environmentally conscious. natural gas transmission and distribution companies want to maintain their image as suppliers of clean fuel. Further reductions in methane leakage --- particularly in older distribution systems --- can, should and will be pursued. Unfortunately, there has been little exchange of views on methane leakages between commentators on environmental matters and gas companies and organizations. There is absolutely no need for the industry to avoid the issue of greenhouse gases. Without industry involvement, the environmental debate concerning fossil fuels could lead to selective interpretation of scientific views and available evidence. Companies and authorities would be presented with confusing, contradictory evidence on which to base policy approaches and regulations

  5. Construction of new education system on nuclear energy and radiation after experience of Fukushima Daiichi Nuclear Power Plant accident. Improvement of response capability of educational fields against nuclear power plant accident

    International Nuclear Information System (INIS)

    Matsuzuru, Hideo; Chida, Mitsuhisa; Sakurai, Fumio; Hirose, Masami

    2011-01-01

    Fukushima Daiichi Nuclear Power Plant (NPP) accident brought about confusion in elementary and secondary educational fields due to lack of teacher's knowledge of nuclear power, radiation safety and protection, and information about regional radiation and radioactivity data. In order to improve their response capability against NPP accident to secure safety of the pupil and student, new education system on nuclear energy and radiation was constructed such as educational course of 'nuclear energy and radiation safety' for pre-service teacher training system faculty students and training course of 'radiation dose measurement and evaluation' for in-service teacher and professors. Feasibility studies were also performed to construct information network for supporting schools at NPP accident so as to provide effective information about radiation and radioactivity data for educational fields. (T. Tanaka)

  6. Comparison Of Taxis And Logical Semantic Systems In Indonesian And Malaysian Newspapers About Airasia Qz8501 Accident

    OpenAIRE

    Syahputra, Yudha

    2016-01-01

    This study seeks to describe the comparative portion of taxis and logical semantic systems between Malaysian and Indonesian newspapers’ articles about AirAsia QZ8501 accident. The data are clause complexes in Indonesia naval captain says may have located missing plane tail’s section’s New Straits Times (Text A) and AirAsia tail section located, blackbox still missing’s The Jakarta Post (Text B) articles. This study uses qualitative-descriptive method. As the result, both par...

  7. The association between attributions of responsibility for motor vehicle accidents and patient satisfaction: a study within a no-fault injury compensation system.

    Science.gov (United States)

    Thompson, Jason; Berk, Michael; O'Donnell, Meaghan; Stafford, Lesley; Nordfjaern, Trond

    2015-05-01

    This study set out to test the relationship between attributions of responsibility for motor vehicle accidents and satisfaction with personal injury compensation systems. The study analysed survey data from 1394 people injured in a motor vehicle accident who were compensated under a no-fault personal injury compensation system. Patients' ratings of satisfaction with the compensation system across five domains (resolves your issues, keeps you up-to-date, treats you as an individual, cares about you, and overall satisfaction) were analysed alongside patient attributions of responsibility for their accident (not responsible, partly responsible, totally responsible). Postaccident physical and mental health status, age, gender, and duration of compensation claim were controlled for in the analysis. A multivariate analysis of covariance indicated attributions of responsibility for accidents were significantly associated with levels of patient satisfaction across all five domains under study (F (10, 2084) = 3.7, presponsibility for their accidents to others were significantly less satisfied with the injury compensation system than those who attributed responsibility to themselves. Satisfaction with no-fault motor vehicle injury compensation services are associated with patients' attributions of responsibility for their accident. Compensation systems and other rehabilitation services monitoring patient satisfaction should adjust for attributions of responsibility when assessing levels of patient satisfaction between time periods, services, or injured populations. Differences in levels of patient satisfaction observed between compensation or rehabilitation populations may reflect differences in attributions of responsibility for accidents rather than objective service quality. © The Author(s) 2014.

  8. Development of the accident simulation system 'IMPACT' for light water nuclear power plants

    International Nuclear Information System (INIS)

    Naitoh, Masanori; Ando, Yasumasa; Ujita, Hiroshi

    1999-01-01

    The total plan, software contents and analysis results of IMPACT are reported. IMPACT is entrusted business from Ministry of International Trade and Industry to verify safety against severe accidents in light water nuclear power plants by computer simulation. The IMPACT codes for simulation are featured by adoption of mechanistic models and module structure, assuming use of parallel computers for a series of events from normal operation to severe accidents. The IMPACT business is a long term project for 10 years, and aims at completion of a boiling transition behavior analysis code and a fluid/structure interaction analysis code as short-term targets and a severe accident analysis code as a long-term target. So far the codes of the former two items and a prototype version of the latter have been completed, and their verification analysis is being carried out. (M.M.)

  9. Twenty-second ORNL intercomparison of criticality accident dosimetry systems, August 12-16, 1985

    International Nuclear Information System (INIS)

    Swaja, R.E.; Oyan, R.; Sims, C.S.

    1986-05-01

    The twenty-second in a series of criticality accident dosimetry intercomparison studies was conducted at the Oak Ridge National Laboratory's Dosimetry Applications Research Facility during August 12-16, 1985. The Health Physics Research Reactor operated in the pulse mode over Storage Pit No. 1 was used to simulate three criticality accidents with different radiation fields. Participants from nine organizations measured neutron doses between 0.36 and 3.78 Gy and gamma doses between 0.22 and 0.80 Gy at area monitoring stations and on phantoms. Approximately 68% of all neutron dose estimates based on foil activation, thermoluminescent, hair activation, and blood sodium activation methods were within +-25% of reference values. About 44% of all gamma results measured using thermoluminescent dosimeters (TLD-700 or CaSO 4 phosphors) were within 20% of reference doses. The generally poor measurement accuracy exhibited in this study indicates a need for continuing ORNL accident dosimetry intercomparison and training programs

  10. Analysis of three loss-of-flow accidents in the first wall cooling system of NET/ITER

    International Nuclear Information System (INIS)

    Komen, E.M.J.; Koning, H.

    1993-05-01

    This report presents the thermal-hydraulic analysis of three Loss-of-Flow Accidents (LOFAs) in the first wall cooling system of the Next European Torus (NET) design or the International Thermonuclear Experimental Reactor (ITER) design. The LOFAs considered result from a loss of the forced coolant flow caused by a loss of electrical power for the recirculation pump in the primary circuit. The analyses have been performed using the thermal-hydraulic system analysis code RELAP5/MOD3. In the analyses, special attention has been paid to the transient thermal-hydraulic behaviour of the cooling system and the temperature development in the first wall. In the LOFA case without plasma shutdown, melting starts in the first wall about 150 s after accident initiation. In the LOFA case with delayed plasma shutdown, melting starts in the first wall when the plasma shutdown is initiated later than about 110 s after accident initiation. Melting does not occur in the first wall during a LOFA with prompt plasma scram. (orig.)

  11. System of regional centres of first aid in cases of radiation accidents in Germany

    International Nuclear Information System (INIS)

    Fehringer, F.; Seitz, G.

    1996-01-01

    When in the seventies the number of occupational radiation exposed persons in the Federal Republic of Germany increased from about 35,000 (1974) to about 160,000 (1978) the Industrial Injuries Insurance Institutes felt prompted to reflect about special measures to prevent radiation accidents and provide health care for this special cases. They did so without any actual occasion: accidents were persons have been exposed by ionizing radiation were in the seventies just as rare as today. But that fact does not allow the Industrial Injuries Insurance Institutes to neglect the existing potential for severe accidents. So the Industrial Injuries Insurance Institute for the Electrical Industry including Precision Mechanics and the Industrial Injuries Insurance Institute for the Chemical Industry created the Institute for Radiation Protection in 1978. The primary task of that Institute is to guarantee an effective first aid in the case of a radiation accident. To realize that task the Institute contracted 11 wellknown institutions like radiological departments of large hospitals or the medical departments of research centres where the i knowledge on diagnostic and therapy of radiation effects is present. They are called 'Regionale Strahlenschutzzentren', Regional Centres for Radiation Protection (RCRP). In the case of radiation accidents these RCRP are the logistical centres for all arising questions of treatment. They have facilities for reconstructing exposure situations and assessing and evaluating doses, including measurements of internal contamination as well as for medical inpatient or out-patient treating like internal or external decontamination. Another important task of the RCRP is to advise employers in ad radiation protection questions which arise with the industrial application of ionizing radiation. Of course the centres give also answer to many question from members of the public, for example the personal effects of the power plant accident at Chernobyl

  12. Climate Policy and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the effects of the EU emissions trading scheme on the aluminium sector (i.e. competitiveness loss and carbon leakage). With its very high electricity intensity, primary aluminium stands out in the heavy industry picture: a sector whose emissions are not capped in the present EU ETS, European aluminium smelters still stand to lose profit margins and, possibly, market shares, as electricity prices increase following CO2 caps on generators' emissions - the famous pass-through of CO2 prices into electricity prices. The analysis includes a method of quantification of this issue, based on two indicators: profit margins and trade flows. As the EU is at the forefront of such policy, the paper provides policy messages to all countries on how trade exposed energy-intensive industries can be 'moved' by carbon constraint. This also is a contentious topic in Australia, Japan, New Zealand, and the US, where ambitious climate policies -- including cap-and-trade systems -- are currently debated.

  13. Causative Chain Difference for each Type of Accidents in Japanese Maritime Traffic Systems (MTS)

    OpenAIRE

    Wanginingastuti Mutmainnah; Ludfi Pratiwi Bowo; Achmadi Bambang Sulistiyono; Masao Furusho

    2017-01-01

    Causative chain (CC) is a failure chain that cause accident as an outcome product of the second step of MOP model, namely line relation analysis (LRA). This CC is a connection of several causative factors (CF), an outcome product of first step of MOP model, namely corner analysis (CA). MOP Model is an abbreviation from 4M Overturned Pyramid, created by authors by combining 2 accident analysis models. There are two steps in this model, namely CA and LRA. Utilizing this model can know what is C...

  14. Detection device for pipeway water leakage in building

    International Nuclear Information System (INIS)

    Hanawa, Jun.

    1988-01-01

    Purpose: To rapidly detect pipeway leakage at predetermined areas over a wide range in a building. Constitution: If flooding should occur in a power plant building and left as it is, emergency core cooling system, as well as auxiliary equipments and electrical equipments of the system are flooded to make the safety shutdown of the plant impossible. The present invention copes with such a risk. That is, an inlet flow meter and as exit flow meter are disposed to the inlet and the exit of pipeways disposed in a predetermined region in the building and a flow rate difference detector between them is disposed. In this way, pipeway leakage is detected by detecting the flow rate difference between the inlet flow rate and the exit flow rate of the pipeway in the predetermined region. According to the present invention, if a pipeway in a predetermined region is raptured to cause water leakage, the pipeway leakage can rapidly be detected depending on the flow rate difference between the inlet flow rate and the exit flow rate. Further, the water leakage over the entire the predetermined region can be detected rapidly as compared with the conventional case of detecting the leakage at a restricted portion where the leakage detector is disposed. (Kamimura, M.)

  15. SSYST-1. A computer code system to analyse the fuel rod behaviour during a loss of coolant accident

    International Nuclear Information System (INIS)

    Gulden, W.

    1977-08-01

    The modules of the SSYST program system allow the detailed analysis of an LWR fuel rod in the course of a postulated loss-of-coolant accident. They provide a tool for considering the interaction between the heat conduction in the fuel rod, heat transfer in the gap, fuel and cladding tube deformation, pressure in the coolant, as well as thermal and fluid dynamics in the cooling channel and for calculating the time and location of ballooning and rod failure, respectively. They can be used both to precalculate the behaviour of fuel rods during LWR accidents and in support of the design of experiments. Depending on the problem to be solved, the individual modules can be easily combined. (orig.) [de

  16. EUROCONTROL-Systemic Occurrence Analysis Methodology (SOAM)-A 'Reason'-based organisational methodology for analysing incidents and accidents

    International Nuclear Information System (INIS)

    Licu, Tony; Cioran, Florin; Hayward, Brent; Lowe, Andrew

    2007-01-01

    The Safety Occurrence Analysis Methodology (SOAM) developed for EUROCONTROL is an accident investigation methodology based on the Reason Model of organisational accidents. The purpose of a SOAM is to broaden the focus of an investigation from human involvement issues, also known as 'active failures of operational personnel' under Reason's original model, to include analysis of the latent conditions deeper within the organisation that set the context for the event. Such an approach is consistent with the tenets of Just Culture in which people are encouraged to provide full and open information about how incidents occurred, and are not penalised for errors. A truly systemic approach is not simply a means of transferring responsibility for a safety occurrence from front-line employees to senior managers. A consistent philosophy must be applied, where the investigation process seeks to correct deficiencies wherever they may be found, without attempting to apportion blame or liability

  17. Preventing Tire Blowout Accidents: A Perspective on Factors Affecting Drivers’ Intention to Adopt Tire Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    Kai-Ying Chen

    2018-04-01

    Full Text Available The aim of this study is to explore whether risk perception or anticipated regret is responsible for intensifying the participants’ intention to adopt a tire pressure monitoring system (TPMS to prevent a tire-related accident, and whether the optimism bias has a moderator effect between risk perception/anticipated regret and intention. With 274 valid questionnaires and PLS-SEM (partial least squares structural equation modeling analysis, the results indicate a significant positive relationship between risk perception and intention to adopt TPMS, but not between anticipated regret and intention. The moderator effect of optimism bias on risk perception and anticipated regret is not found in the model. The findings will prove useful for public service advertising campaigns by providing a basis for an understanding of the role of cognitive and emotional factors in tire-blowout accident prevention, thereby increasing the motivation for drivers in Taiwan to take advantage of the protection afforded them by using TPMS.

  18. Severe accident insights report

    International Nuclear Information System (INIS)

    Pratt, W.T.

    1988-04-01

    This report describes the conditions and events that nuclear power plant personnel may encounter during the latter stages of a severe core damage accident and what the consequences might be of actions they may take during these latter stages. The report also describes what can be expected of the performance of the key barriers to fission product release (primarily containment systems), what decisions the operating staff may face during the course of a severe accident, and what could result from these decisions based on our current state of knowledge of severe accident phenomena. 9 refs

  19. 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)

  20. Decision support systems for major accident prevention in the chemical process industry : A developers' survey

    NARCIS (Netherlands)

    Reniers, Genserik L L; Ale, B. J.M.; Dullaert, W.; Foubert, B.

    2006-01-01

    Solid major accident prevention management is characterized by efficient and effective risk assessments. As a means of addressing the efficiency aspect, decision support analysis software is becoming increasingly available. This paper discusses the results of a survey of decision support tools for

  1. The cause-consequence data base: a retrieval system for records pertaining to accident management

    International Nuclear Information System (INIS)

    Kumamoto, H.; Inoue, K.; Sawaragi, Y.

    1981-01-01

    This paper describes a proposal to store in a data base important paragraphs from reports of investigations into many types of accidents. The data base is to handle not only reports on TMI, but also reports on other events at nuclear reactors, chemical plant explosions, earthquakes, hurricanes, fires, and so forth. (author)

  2. APT Blanket System Loss-of-Coolant Accident Based on Initial Conceptual Design - Case 5: External RHR Break Near Inlet Header

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L.L.

    1998-10-07

    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.

  3. 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

  4. Leakage pattern of linear accelerator treatment heads from multiple vendors

    International Nuclear Information System (INIS)

    Lonski, P.R.; Taylor, M.L.; Franich, R.D.; Harty, P.; Clements, N.; Kron, T.

    2011-01-01

    Full text: Patient life expectancy post-radiotherapy is becoming longer. Therefore, secondary cancers caused by radiotherapy treatment have more time to develop. Increasing attention is being given to out-of-field dose resulting from scatter and accelerator head leakage. Dose leakage from equivalent positions on Varian600C, Varian21-X, Siemens Primus and Elekta Synergy-II linacs were measured with TLD 1 00 H dosimeter chips and compared. Treatment parameters such as field size and beam energy were altered. Leakage doses are presented as a percentage of the dose to isocentre (5 Gy). Results illustrate significant variations in leakage dose between linac models where no model emits consistently lower amounts of radiation leakage for all treatment parameters. Results are shown below. Leakage through the collimator assembly in different units is varying as a function of location and unit design by more than a factor of 10. Differences are more pronounced in comparing Varian or Elekta models, which are fitted with an additional collimator separate from the MLC leaves, to the Siemens model, which uses MLC leaves as its only secondary collimator. Further measurements are currently being taken at the patient plane with a directional detector system to determine the spatial distribution of high leakage sources.

  5. Safety analysis of tritium recycling system

    International Nuclear Information System (INIS)

    Yang Yong; Zhang Dong; Xing Shixiong

    2009-04-01

    Safety of a tritium recycling system is analysed according to the structure of the system. The method of accident tree is used to analyse the leakage probability of the system. The result show that the leakage probability of the system failure is 1.1 x 10 -3 and the leakage probability of human fault is 7.2 x 10 -3 , which is are in safe limit. But the leakage probability of human fault is higher than system failure. The MCA will occur because of tritium waste emission cell breakage or misplay, in this case, all tritium in the system will leak, which is about 5.84 TBq. The maximal effective individual dose is 1.24 x 10 -3 mSv, the maximal effective close of the collectivity is 15.33 Person·mSv. (authors)

  6. Hormone regulation system and cyclic nucleotids in the Chernobyl accident liquidators with doses absorbed less then 1 Gy

    International Nuclear Information System (INIS)

    Kovalenko, A.N.

    1997-01-01

    During 6 years after the accident (1987-1992) a functional state of endocrine system that regulate the adaptation, reproduction, metabolism, vessels tonicity and water-electrolyte balance were investigated in 249 liquidators with doses absorbed less then 1 Gy. The changes of these systems activity in state of basal secretion and peculiarities of their reactions under influence of perturbation (adrenaline, insulin) were revealed. Post-irradiation endocrinopathy was characterized and its role in decrease of the organism's adaptation and in mechanism of sanogenesis and pathogenesis was found. (author)

  7. Time reversal technique for gas leakage detection.

    Science.gov (United States)

    Maksimov, A O; Polovinka, Yu A

    2015-04-01

    The acoustic remote sensing of subsea gas leakage traditionally uses sonars as active acoustic sensors and hydrophones picking up the sound generated by a leak as passive sensors. When gas leaks occur underwater, bubbles are produced and emit sound at frequencies intimately related to their sizes. The experimental implementation of an acoustic time-reversal mirror (TRM) is now well established in underwater acoustics. In the basic TRM experiment, a probe source emits a pulse that is received on an array of sensors, time reversed, and re-emitted. After time reversal, the resulting field focuses back at the probe position. In this study, a method for enhancing operation of the passive receiving system has been proposed by using it in the regime of TRM. Two factors, the local character of the acoustic emission signal caused by the leakage and a resonant nature of the bubble radiation at their birth, make particularly effective scattering with the conjugate wave (CW). Analytical calculations are performed for the scattering of CW wave on a single bubble when CW is formed by bubble birthing wail received on an array, time reversed, and re-emitted. The quality of leakage detection depends on the spatio-temporal distribution of ambient noise.

  8. Lessons learnt from an international intercomparison of national network systems used to provide early warning of a nuclear accident

    International Nuclear Information System (INIS)

    As part of the European Research Council's Fourth Framework Programme, the EURADOS Action Group on Monitoring of External Exposures held an intercomparison of national network systems. This took place during May/June 1999 at the Riso Natural Environmental Radiation Measurement Station in Denmark and at the Underground Laboratory for Dosimetry and Spectrometry of the Physikalisch-Technische Bundesanstalt in Germany. The network systems are used continuously to monitor radiation levels throughout a country in order to give early warning of nuclear accidents having transboundary implications. The radiation levels measured are used to estimate the radiation risks to people arising from the accident. Seven European countries participated in the intercomparison with detector systems used in their national network systems as well as with detectors being developed for future use. Since different radiation quantities were measured by the systems (namely exposure, air kerma and ambient dose equivalent), the initial analysis of the intercomparison results was made in terms of the quantity air kerma rate. This report completes the analysis of the results and these are given in terms of air kerma rate in order to be consistent with the preliminary report. In addition, in some cases the results are also given in terms of the quantity measured by each national network system. The experience gained from this intercomparison is used to help organise a follow-up intercomparison to be held at the PTB Braunschweig in September 2002 and in which a further seven or eight countries from Europe will participate. (author)

  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. Effect of Spray System on Fission Product Distribution in Containment During a Severe Accident in a Two-Loop Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Mehdi Dehjourian

    2016-08-01

    Full Text Available The containment response during the first 24 hours of a low-pressure severe accident scenario in a nuclear power plant with a two-loop Westinghouse-type pressurized water reactor was simulated with the CONTAIN 2.0 computer code. The accident considered in this study is a large-break loss-of-coolant accident, which is not successfully mitigated by the action of safety systems. The analysis includes pressure and temperature responses, as well as investigation into the influence of spray on the retention of fission products and the prevention of hydrogen combustion in the containment.

  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. Sports Accidents

    CERN Document Server

    Kiebel

    1972-01-01

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

  14. Japan's compensation system for nuclear damage - As related to the TEPCO Fukushima Daiichi nuclear accidents

    International Nuclear Information System (INIS)

    Nomura, Toyohiro; Matsuura, Shigekazu; Takahashi, Yasufumi; Takenaka, Chihiro; Hokugo, Taro; Kamada, Toshihiko; Kamai, Hiroyuki

    2012-01-01

    Following the TEPCO Fukushima Daiichi nuclear power plant accident, extraordinary efforts were undertaken in Japan to implement a compensation scheme for the proper and efficient indemnification of the affected victims. This publication provides English translations of key Japanese legislative and administrative texts and other implementing guidance, as well as several commentaries by Japanese experts in the field of third party nuclear liability. The OECD Nuclear Energy Agency (NEA) has prepared this publication in co-operation with the government of Japan to share Japan's recent experience in implementing its nuclear liability and compensation regime. The material presented in the publication should provide valuable insights for those wishing to better understand the regime applied to compensate the victims of the accident and for those working on potential improvements in national regimes and the international framework for third party nuclear liability

  15. Development of a diagnostic system for identifying accident conditions in a reactor

    International Nuclear Information System (INIS)

    Santhosh; Gera, B.; Kumar, Mithilesh; Thangamani, I.; Prasad, Hari; Srivastava, A.; Dutta, Anu; Sharma, Pavan K.; Majumdar, P.; Verma, V.; Mukhopadhyay, D.; Ganju, Sunil; Chatterjee, B.; Sanyasi Rao, V.V.S.; Lele, H.G.; Ghosh, A.K.

    2009-07-01

    This report describes a methodology for identification of accident conditions in a nuclear reactor from the signals available to the operator. A large database of such signals is generated through analyses - for core, containment, environmental dispersion and radiological dose to train a computer code based on an Artificial Neural Networks (ANNs). At present, in the prediction mode, information on LOCA (location and size of break), status of availability of ECCS, and expected doses can be predicted well for a 220 MWe PHWR. (author)

  16. Agricultural countermeasure program - AGRICP: food and dose module in ARGOS- accident reporting and Guidance Operational System

    International Nuclear Information System (INIS)

    Calábria, Jaqueline A.A.; Morais, Gustavo F.

    2017-01-01

    Nuclear or radiological emergencies can affect food, feed and commodities grown. The regulatory bodies has a role in the post-accident phase instructing the population regarding the consumption of agricultural products, monitoring and recovering the contaminated areas and disposing the generated waste. To deal with nuclear/radiological emergencies, in the end of 2007, Brazil took part of the ARGOS consortium. ARGOS is a software used for support the Preparedness and Response of a nuclear emergency. Specifically for use during the recovery phase, ARGOS has a module called AgriCP (Agricultural Countermeasure Program). This functionality was add to the version 9.0 of ARGOS, in 2012, replacing FMD (Food and Dose Module) model. AgriCP can be very useful in the post-accident phasing, helping to planning the actions that must be taken, saving human and budged resources. However, most of the parameters used by default for the model are specific for Central Europe and must be adapted to the Brazilian characteristics. In this paper the basic functionalities of AgriCP are presented and a general view of the issues to be addressed while implementing AgriCP for the Brazilian case is given. Besides the lack of specific parameters for the Brazilian reality, the definition of the area to be considering for intervention in an accident, taking into account the very complex meteorological characteristic of the Brazilian NPPs (nuclear power plants) site, are some of the matters of concern. (author)

  17. Agricultural countermeasure program - AGRICP: food and dose module in ARGOS- accident reporting and Guidance Operational System

    Energy Technology Data Exchange (ETDEWEB)

    Calábria, Jaqueline A.A.; Morais, Gustavo F., E-mail: jaqueline.calabria@cnen.gov.br, E-mail: gustavo.morais@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    Nuclear or radiological emergencies can affect food, feed and commodities grown. The regulatory bodies has a role in the post-accident phase instructing the population regarding the consumption of agricultural products, monitoring and recovering the contaminated areas and disposing the generated waste. To deal with nuclear/radiological emergencies, in the end of 2007, Brazil took part of the ARGOS consortium. ARGOS is a software used for support the Preparedness and Response of a nuclear emergency. Specifically for use during the recovery phase, ARGOS has a module called AgriCP (Agricultural Countermeasure Program). This functionality was add to the version 9.0 of ARGOS, in 2012, replacing FMD (Food and Dose Module) model. AgriCP can be very useful in the post-accident phasing, helping to planning the actions that must be taken, saving human and budged resources. However, most of the parameters used by default for the model are specific for Central Europe and must be adapted to the Brazilian characteristics. In this paper the basic functionalities of AgriCP are presented and a general view of the issues to be addressed while implementing AgriCP for the Brazilian case is given. Besides the lack of specific parameters for the Brazilian reality, the definition of the area to be considering for intervention in an accident, taking into account the very complex meteorological characteristic of the Brazilian NPPs (nuclear power plants) site, are some of the matters of concern. (author)

  18. Long-term distribution of Cs-137 in freshwater ecosystem and the effect of bioturbation on leakage of Cs-137 from the sediments

    International Nuclear Information System (INIS)

    Aquilonius, K.

    1995-06-01

    The first aim of the project was to make a literature compilation regarding Cs-137 in freshwater systems. Secondly, in order to follow up the long-term behaviour of Cs-137 in Lake Hillesjoen, sediment and water was sampled with respect to Cs-137. Finally, an experiment was done with chironomids, with the aim to assess the impact of bioturbation on the leakage of Cs-137 from the sediment, since this is one of the factors contributing to the uncertainties in radioecological models. Some aspects of long-term distribution of Cs-137 in freshwater lakes is discussed. In lake Hillesjoen the pool of Cs-137 in sediments (225 kBq/m 2 , 1993) has gradually increased since the Chernobyl accident, and now exceeds the initial deposition (100 kBq/m 2 ). The effect of bioturbation on the leakage from the sediment to the water could not be clarified in this experiment, but is discussed. 40 refs

  19. Radiation Fields Near Buildings in Case of Radionuclide Leakage

    International Nuclear Information System (INIS)

    Deme, S.; Lang, E.; Pazmandi, T.; Sagi, L.; Goricsan, I.; Szepesi, Zs.

    2001-01-01

    Full text: In case of an accident of nuclear facilities radionuclide emission due to leakage the source term is not measurable by usual stack monitors. For determination of the source term ring type detector systems located around nuclear facilities are often used. Such a system requests 15-25 detectors at a distance of 1-3 km. Based on meteorological data the source term can be estimated. In some cases (e.g. in case of complex terrain) such a method does not provide sufficient accuracy or is too expensive. For such cases the detectors of the monitoring system can be located near building emitting radionuclides. For calculation of the response of the detectors the usual Gaussian-plume approximation method is not valid and no any other relatively simple calculations are not known as in the building wake the turbulent dispersion is very complex. The paper deals with experimental determination of contaminant dispersion in the building wake zone. The 1:250 scale model of the Budapest Research Reactor was used at the wind tunnel of the Budapest Technical University. The radionuclide emission through the wall was simulated by oil fog. This fog was illuminated by a plane laser beam and the two dimensional distribution was determined by a digital measuring camera. Taking a set of such pictures the full three-dimensional concentration grid was received. Using these data the ratio of emission and detector response was calculated for gamma-emitters. The same data can be used for determination of dose distribution and for initial dispersion parameters as well. (author)

  20. Application of the Bulgarian emergency response system in case of nuclear accident in environmental assessment study

    Science.gov (United States)

    Syrakov, Dimiter; Veleva, Blagorodka; Georgievs, Emilia; Prodanova, Maria; Slavov, Kiril; Kolarova, Maria

    2014-05-01

    The development of the Bulgarian Emergency Response System (BERS) for short term forecast in case of accidental radioactive releases to the atmosphere has been started in the mid 1990's [1]. BERS comprises of two main parts - operational and accidental, for two regions 'Europe' and 'Northern Hemisphere'. The operational part runs automatically since 2001 using the 72 hours meteorological forecast from DWD Global model, resolution in space of 1.5o and in time - 12 hours. For specified Nuclear power plants (NPPs), 3 days trajectories are calculated and presented on NIMH's specialized Web-site (http://info.meteo.bg/ews/). The accidental part is applied when radioactive releases are reported or in case of emergency exercises. BERS is based on numerical weather forecast information and long-range dispersion model accounting for the transport, dispersion, and radioactive transformations of pollutants. The core of the accidental part of the system is the Eulerian 3D dispersion model EMAP calculating concentration and deposition fields [2]. The system is upgraded with a 'dose calculation module' for estimation of the prognostic dose fields of 31 important radioactive gaseous and aerosol pollutants. The prognostic doses significant for the early stage of a nuclear accident are calculated as follows: the effective doses from external irradiation (air submersion + ground shinning); effective dose from inhalation; summarized effective dose and absorbed thyroid dose [3]. The output is given as 12, 24, 36, 48, 60 and 72 hours prognostic dose fields according the updated meteorology. The BERS was upgraded to simulate the dispersion of nuclear materials from Fukushima NPP [4], and results were presented in NIMH web-site. In addition BERS took part in the respective ENSEMBLE exercises to model 131I and 137Cs in Fukushima source term. In case of governmental request for expertise BERS was applied for environmental impact assessment of hypothetical accidental transboundary

  1. Conceptual design of emergency communication system to cope with severe accidents in NPPs and its performance evaluation

    International Nuclear Information System (INIS)

    Son, Kwang Seop; Kim, Chang Hwoi; Kang, Hyun Gook

    2015-01-01

    Highlights: • The emergency communication system requires the performances of the throughput of 1 Mbps, BER of 10 −6 and network configuration of 1:12 communication. • The emergency communication system consists of the terrestrial communication and satellite communication system. • In the terrestrial communication system, at least two wireless repeaters are needed to secure LOS and the throughput and delay time are 16 Mbps and 16 ms, respectively. • In the satellite communication system, DSSS and FDMA are used and the fade margin range is from 1.3 to 16 dB. - Abstract: The Fukushima accident induced by the great earthquake and tsunami reveals the vulnerability of I and C System. In the severe environment, the normal I and C system did not work properly and results in false information about the internal situation in NPP. Eventually the accident was not properly handled at the early stage. Therefore advanced emergency response system using a wireless channel is necessary to cope with the severe accident. In this paper, we introduce the ERS consisting of the HMS and MCS the ECS linking the HMS with MCS and the performance requirement of the ECS is analyzed. The ECS satisfying the requirement is designed conceptually and the performance of the ECS is evaluated through analysis and simulator. To secure a reliable and diverse configuration, the ECS is configured as the dual system which consists of the terrestrial communication and satellite communication. The terrestrial communication system is designed based on the IEEE 802.11. Analyzed performance results prove that the performance requirement can be sufficiently achieved. But if the scalability of data capacity is considered later, use of the advanced 802.11 standard such as 802.11n and multiple signal paths between the HMS and MCS are necessary. In the satellite communication system, the FDMA is used in the status link and the DSSS is used in the control link. The network supporting various data rates is

  2. Development of severe accident evaluation technology (level 2 PSA) for sodium-cooled fast reactors. (5) Identification of dominant factors in ex-vessel accident sequences

    International Nuclear Information System (INIS)

    Ohno, Shuji; Seino, Hiroshi; Miyahara, Shinya

    2009-01-01

    The evaluation of accident progression outside of a reactor vessel (ex-vessel) and subsequent transfer behavior of radioactive materials is of great importance from the viewpoint of Level 2 PSA. Hence typical ex-vessel accident sequences in the JAEA Sodium-cooled Fast Reactor are qualitatively discussed in this paper and dominant behaviors or factors in the sequences are investigated through parametric calculations using the CONTAIN/LMR code. Scenarios to be focused on are, 1) sodium vapor leakage from the reactor vessel and 2) sodium-concrete reaction, which are both to be considered in the accident category of LOHRS (loss of heat removal system) and might be followed by an early containment failure due to the thermal effect of sodium combustion and hydrogen burning respectively. The calculated results clarify that the sodium vapor leak rate and the scale of sodium-concrete reaction are the important factors to dominate the ex-vessel accident progression. In addition to the understandings of the dominant factors, the analyzed results also provide the specific information such as pressure loading value to the containment and the timing of pressurization, which is indispensable as technical base in Level 2 PSA for developing event trees and for quantifying the accident consequences. (author)

  3. WWER steam generator tube structural and leakage integrity

    International Nuclear Information System (INIS)

    Splichal, K.; Krhounek, Vl.; Otruba, J.; Ruscak, M.

    1998-01-01

    The integrity of heat exchange tubes may influence the lifetime of WWER steam generators and appears to be an important criterion for the evaluation of their safety and operational reliability. The basic requirements are to assure very low probability of radioactive water leakage, preventing unstable crack growth and sudden tube rupture. These requirements led to development of permissible limits for primary to secondary leak evaluation and heat exchange tubes plugging. The stress corrosion cracking and pitting are the main corrosion damages of WWER heat exchange tubes and are initiated from the outer surface. Both the initiation and crack growth cause thinning of the tube wall and lead to part thickness cracks and through wall cracks, oriented preferentially in the axial direction. The paper presents the leakage and plugging limits for WWER steam generators, which have been determined from leak tests and burst tests. The tubes with axial part-through and through-wall defects have been used. The permissible value of primary to secondary leak rate was evaluated with respect to permissible axial through-wall defect size of WWER 440 and 1000 steam generator tubes. Blocking of the tube cracks by corrosion product particles and other compounds reduces the primary to secondary leak rate. The plugging limits involve the following factors: permissible tube wall thickness which determine further operation of the tubes with defects and assures their integrity under operating conditions and permissible size of a through-wall crack which is sufficiently stable under normal and accident conditions in relation to the critical crack length. For the evaluation of burst test of heat exchange tubes with longitudinal through-wall defects the instability criterion has been used and the dependence of the normalised burst pressure on the normalised length of an axial through-wall defect has been determined. The validity of the criterion of instability for WWER tubes with through

  4. Development of Public Training System for Emergency Exercise Using Virtual Reality Technology Based on Radioactive Release Accident

    International Nuclear Information System (INIS)

    Lee, Byung Il; Park, Seong Jun; Lee, Dewhey; Song, Sub Lee; Park, Younwon

    2016-01-01

    An exercise is normally conducted for a day or two days depending on the scale of the exercise. What we have experienced up to date there are several limitations in the radiological emergency exercises such as low public acceptance, poor enthusiasm in the exercise participation, not very attracting exercise scenarios, low efficiency in conducting an exercise, and so on. In order to overcome the limitations of the present exercising system, we would like to develop a radiological emergency exercise system using VR (virtual reality) technology based on a radioactive release accident. In this paper, we just introduce some basic development methods and event tree based scenario as a beginning stage. After the accident in Fukushima Daiichi NPP, the importance of emergency exercise especially for the public is far more emphasized around the world more and more. However, the human labor focused radiological emergency exercise up to now has many limitations. After developing this system properly and by using it, we could even expect to estimate the weak points of the emergency arrangements and strategy we have

  5. Development of Public Training System for Emergency Exercise Using Virtual Reality Technology Based on Radioactive Release Accident

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Il; Park, Seong Jun; Lee, Dewhey; Song, Sub Lee; Park, Younwon [BEES Inc., Daejeon (Korea, Republic of)

    2016-10-15

    An exercise is normally conducted for a day or two days depending on the scale of the exercise. What we have experienced up to date there are several limitations in the radiological emergency exercises such as low public acceptance, poor enthusiasm in the exercise participation, not very attracting exercise scenarios, low efficiency in conducting an exercise, and so on. In order to overcome the limitations of the present exercising system, we would like to develop a radiological emergency exercise system using VR (virtual reality) technology based on a radioactive release accident. In this paper, we just introduce some basic development methods and event tree based scenario as a beginning stage. After the accident in Fukushima Daiichi NPP, the importance of emergency exercise especially for the public is far more emphasized around the world more and more. However, the human labor focused radiological emergency exercise up to now has many limitations. After developing this system properly and by using it, we could even expect to estimate the weak points of the emergency arrangements and strategy we have.

  6. Determination of the response function for the Portsmouth Gaseous Diffusion Plant criticality accident alarm system neutron detectors

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; Brown, A.S.; Dobelbower, M.C.; Woollard, J.E.

    1997-03-01

    Neutron-sensitive radiation detectors are used in the Portsmouth Gaseous Diffusion Plant's (PORTS) criticality accident alarm system (CAAS). The CAAS is composed of numerous detectors, electronics, and logic units. It uses a telemetry system to sound building evacuation horns and to provide remote alarm status in a central control facility. The ANSI Standard for a CAAS uses a free-in-air dose rate to define the detection criteria for a minimum accident-of-concern. Previously, the free-in-air absorbed dose rate from neutrons was used for determining the areal coverge of criticality detection within PORTS buildings handling fissile materials. However, the free-in-air dose rate does not accurately reflect the response of the neutron detectors in use at PORTS. Because the cost of placing additional CAAS detectors in areas of questionable coverage (based on a free-in-air absorbed dose rate) is high, the actual response function for the CAAS neutron detectors was determined. This report, which is organized into three major sections, discusses how the actual response function for the PORTS CAAS neutron detectors was determined. The CAAS neutron detectors are described in Section 2. The model of the detector system developed to facilitate calculation of the response function is discussed in Section 3. The results of the calculations, including confirmatory measurements with neutron sources, are given in Section 4

  7. Leakage tests of the wall segments of a prestressed concrete containment building

    International Nuclear Information System (INIS)

    Choun, Young Sun; Cho, Nam So

    2005-01-01

    Containment buildings have to maintain their air tightness under extreme loading conditions such as earthquakes, missile impact, and severe accidents to maintain their functional integrity. For evaluating the functional failure of containment buildings, it is important to predict the leakage level through cracked concrete walls. The leakage through concrete cracks has been studied since 1972. Buss examined the flow rate of air through a pre-existing crack in a slab under air pressure. Rizkalla el al. initiated an experimental study for the leakage of prestressed concrete building segments under uniaxial and biaxial loadings to simulate the loading condition of containment buildings under an internal pressure. Recently, Salmon el al. initiated an experimental program for determining the leak rates in typical reinforced concrete shear walls subjected to beyond design basis earthquakes. This study determined the leak rate for the wall segments of a prestressed concrete containment building through leakage tests

  8. RELAP5 simulation of a large break Loss of Coolant Accident (LOCA) in the hot leg of the primary system in Angra 2 nuclear power plant

    International Nuclear Information System (INIS)

    Andrade, Delvonei Alves de; Sabundjian, Gaiane

    2004-01-01

    The objective of this work is to present the simulation of a large break loss of coolant accident - LBLOCA in the hot leg of the primary loop in Angra 2, with RELAP5/MOD3.2.2g code. This accident is described in the Final Safety Report Analysis of Angra 2 - FSAR and consists basically of the hot leg total break, in loop 20 of the plant. The area considered for the rupture is 4480 cm 2 , which corresponds to 100% of the pipe flow area. Besides, this work also has the objective of verifying the efficiency of the emergency core coolant system - ECCS in case of accidents and transients. The thermal-hydraulic processes inherent to the accident phenomenology, such as hot leg vaporization and consequently core vaporization causing an inappropriate flow distribution in the reactor core, can lead to a reduction in the liquid level, until the ECCS is capable to reflood it

  9. Pilot Study for the Creation of a European Union Radiation Accident and Incident Data Exchange System (EURAIDE)

    International Nuclear Information System (INIS)

    Stewart, J.E.; Lefaure, C; Czarwinski, R.

    2004-01-01

    This study has had the objective of evaluating the feasibility of: (i) facilitating the establishment of national radiation accident and incident databases where there are none and to encourage the compatibility of such databases, (ii) establishing a European network to exchange radiological protection feedback from accidents and incidents, (iii) establishing summary reports of relevant accidents and incidents with the aim of identifying lessons to be learned, so that they can be used in radiation protection training programs, and (iv) upgrading the radiological safety in the countries applying to join the EU, by integrating them into the above efficient feedback exchange system. This report details the first stage of the project, which was to review the status of existing (or proposed) national mechanisms for collating data on radiation incidents. The objectives of this initial review were to: i) obtain detailed information regarding the means of capturing and collating data, the format of established or proposed data systems and accessibility of the final data, ii) to use this information to consider how a European platform to gather relevant data/accident reports might be established., and iii) to consider how the various elements of national data systems might be harmonised in order to facilitate the presentation and distribution of lessons learned. It was considered that the key aspects that would need to be addressed in order to determine the feasibility of a European wide data exchange mechanism were: - the criteria used for the classification and categorisation of incidents, - criteria for the selection of incidents from national data systems for inclusion in a European-wide system, - the implication of possible language problems. In order to illicit the required information a detailed questionnaire was sent to a total of 31 countries, being existing European Member States, applicant or associated countries. A full list of the countries and institutions

  10. Issues behind Competitiveness and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the vulnerability of heavy industry to carbon leakage and competitiveness loss. It reviews the existing literature on competitiveness and carbon leakage under uneven climate policies. It also suggests a statistical method to track carbon leakage, and applies this methodology to Phase I of the EU emissions trading scheme, for various industrial activities: iron and steel, cement, aluminium and refineries. Finally, it reviews measures to mitigate carbon leakage, as discussed in Australia, Canada, Europe, New Zealand and the US.

  11. Simulation of leakage through mechanical sealing device

    Science.gov (United States)

    Tikhomorov, V. P.; Gorlenko, O. A.; Izmerov, M. A.

    2018-03-01

    The procedure of mathematical modeling of leakage through the mechanical seal taking into account waviness and roughness is considered. The percolation process is represented as the sum of leakages through a gap between wavy surfaces and percolation through gaps formed by fractal roughness, i.e. the total leakage is determined by the slot model and filtration leakage. Dependences of leaks on the contact pressure of corrugated and rough surfaces of the mechanical seal elements are presented.

  12. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  13. Electrolyte leakage as an indicator

    Directory of Open Access Journals (Sweden)

    ahmad nezami

    2009-06-01

    Full Text Available In order to evaluate the electrolyte leakage as an indicator of freezing injury in colza (Brassica napus L. genotypes under controlled conditions, a trial carried out at the green house of College of Agriculture, Ferdowsi University of Mashhad. In this study 10 rapeseed genotypes, with 5 temperatures (0, -4, -8, -12 and -16 °C on subplot and acclimation and non acclimation on main plot were evaluated on RCD factorial split plot with two replications. Plants were kept until 3-5 leaf stage in green house condition with 23/16 2 °C (day/night and natural photoperiod. Pots were subjected to acclimation (for three weeks or non acclimation that plants immediately frozen.For acclimation treatment after three weeks freezing was done in thermogradient freezer. The cell membrane integrity was measured through electrolyte leakage and the lethal temperature 50 (LT50 of samples also were determined. There were significant differences (p

  14. Ion induced intermixing and consequent effects on the leakage currents in HfO{sub 2}/SiO{sub 2}/Si systems

    Energy Technology Data Exchange (ETDEWEB)

    Manikanthababu, N.; Saikiran, V.; Pathak, A.P.; Rao, S.V.S.N. [University of Hyderabad, School of Physics, Hyderabad (India); Chan, T.K.; Vajandar, S.; Osipowicz, T. [National University of Singapore, Department of Physics, Centre for Ion Beam Applications (CIBA), Singapore (Singapore)

    2017-05-15

    Atomic layer deposited (ALD) samples with layer stacks of HfO{sub 2} (3 nm)/SiO{sub 2} (0.7 nm)/Si were subjected to 120 MeV Au ion irradiation at different fluences to study intermixing effects across the HfO{sub 2}/SiO{sub 2} interface. High-resolution Rutherford backscattering spectrometry (HRBS) and X-ray reflectivity (XRR) measurements confirm an increase in the interlayer thickness as a result of SHI induced intermixing effects. Current-voltage (I-V) measurements reveal an order of magnitude difference in the leakage current density between the pristine and irradiated samples. This can be explained by considering the increased physical thickness of interlayer (HfSiO). Furthermore, the samples were subjected to rapid thermal annealing (RTA) process to analyze annealing kinetics. (orig.)

  15. EVA Suit Microbial Leakage Investigation Project

    Science.gov (United States)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  16. Time-to-collision analysis of pedestrian and pedal-cycle accidents for the development of autonomous emergency braking systems.

    Science.gov (United States)

    Lenard, James; Welsh, Ruth; Danton, Russell

    2018-06-01

    The aim of this study was to describe the position of pedestrians and pedal cyclists relative to the striking vehicle in the 3 s before impact. This information is essential for the development of effective autonomous emergency braking systems and relevant test conditions for consumer ratings. The UK RAIDS-OTS study provided 175 pedestrian and 127 pedal-cycle cases based on in-depth, at-scene investigations of a representative sample of accidents in 2000-2010. Pedal cyclists were scattered laterally more widely than pedestrians (90% of cyclists within around ±80° compared to ±20° for pedestrians), however their distance from the striking vehicle in the seconds before impact was no greater (90% of cyclists within 42 m at 3 s compared to 50 m for pedestrians). This data is consistent with a greater involvement of slow moving vehicles in cycle accidents. The implication of the results is that AEB systems for cyclists require almost complete 180° side-to-side vision but do not need a longer distance range than for pedestrians. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Compendium of ECCS [Emergency Core Cooling Systems] research for realistic LOCA [loss-of-coolant accidents] analysis: Final report

    International Nuclear Information System (INIS)

    1988-12-01

    In the United States, Emergency Core Cooling Systems (ECCS) are required for light water reactors (LWRs) to provide cooling of the reactor core in the event of a break or leak in the reactor piping or an inadvertent opening of a valve. These accidents are called loss-of-coolant accidents (LOCA), and they range from small leaks up to a postulated full break of the largest pipe in the reactor cooling system. Federal government regulations provide that LOCA analysis be performed to show that the ECCS will maintain fuel rod cladding temperatures, cladding oxidation, and hydrogen production within certain limits. The NRC and others have completed a large body of research which investigated fuel rod behavior and LOCA/ECCS performance. It is now possible to make a realistic estimate of the ECCS performance during a LOCA and to quantify the uncertainty of this calculation. The purpose of this report is to summarize this research and to serve as a general reference for the extensive research effort that has been performed. The report: (1) summarizes the understanding of LOCA phenomena in 1974; (2) reviews experimental and analytical programs developed to address the phenomena; (3) describes the best-estimate computer codes developed by the NRC; (4) discusses the salient technical aspects of the physical phenomena and our current understanding of them; (5) discusses probabilistic risk assessment results and perspectives, and (6) evaluates the impact of research results on the ECCS regulations. 736 refs., 412 figs., 66 tabs

  18. Validation of RALOC4 code for Ignalina NPP Accident Localisation System employing parameters measured during MSV opening

    International Nuclear Information System (INIS)

    Urbonavicius, E.; Rimkevicius, S.

    2001-01-01

    Accident Localisation System (ALS) of Ignalina NPP is a pressure suppression type confinement. It consists of a number of interconnected compartments with 10 condensing pools to condense the accident-generated steam and to reduce the peak pressures that can be reached during any LOCA. The condensing pools are located at five elevations in two ALS towers. In the case of main safety valve (MSV) opening the released steam is directed to the top (5 th ) condensing pool of ALS. The ALS thermal hydraulic parameters measured during unintended opening of single MSV which appeared on November 8, 1998 at Ignalina NPP Unit 2 were used for validation of RALOC4 code (Germany). Post-event calculations performed and the calculated water temperatures and water levels in condensing pools as well as condenser tray cooling system (CTCS) parameters were compared with corresponding measured data. The results of the performed sensitivity analysis showed that in the best-estimate analysis the heat transfer coefficient in CTCS heat exchangers could be increased to 2500 W/(m 2 .K) compared to conservative value of 1000 W/(m 2 .K) applied in former calculations.(author)

  19. Accident rates in mine transport

    Energy Technology Data Exchange (ETDEWEB)

    Skurka, V.

    1987-11-01

    Describes accident trends for mine transport which now, due to increased automation, makes up 60-80% of all mining activities. Gives figures in tabular form for fatalities and serious injuries in organizations under control of State Mining Authority, showing that transport accidents are the most numerous (38% for period 1976-1986), followed by rock bursts (22%) and machinery accidents (10%). Analysis shows that both surface and underground transport are equally involved and that conveyors are the worst offenders, causing 31% of transport accidents during 1976-1986, followed by rail transport with 26% and automobile transport with 16%. Gives further details of precise causes of accidents involving these 3 types of transport and stresses that accidents can be prevented by using transport systems correctly, organizing them correctly, proper maintenance, use of safety devices and good working discipline. 5 refs.

  20. Detection of gaseous heavy water leakage points in CANDU 6 pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Park, T-K.; Jung, S-H.

    1996-01-01

    During reactor operation, the heavy water filled primary coolant system in a CANDU 6 Pressurized Heavy Water (PHWR) may leak through routine operations of the plant via components, mechanical joints, and during inadvertent operations etc. Early detection of leak points is therefore important to maintain plant safety and economy. There are many independent systems to monitor and recover heavy water leakage in a CANDU 6 PHWR. Methodology for early detection based on operating experience from these systems, is investigated in this paper. In addition, the four symptoms of D 2 O leakage, the associated process for clarifying and verifying the leakage, and the probable points of leakage are discussed. (author)

  1. 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

  2. Effects of a hypothetical loss-of-coolant accident on a Mark I Boiling Water Reactor pressure-suppression system

    International Nuclear Information System (INIS)

    Pitts, J.H.; McCauley, E.W.

    1977-01-01

    A loss-of-coolant accident (LOCA) in a boiling-water-reactor (BWR) power plant has never occurred. However, because this type of accident could be particularly severe, it is used as a principal theoretical basis for design. A series of consistent, versatile, and accurate air-water tests that simulate LOCA conditions has been completed on a 1 / 5 -scale Mark I BWR pressure-suppression system. Results from these tests are used to quantify the vertical-loading function and to study the associated fluid dynamics phenomena. Detailed histories of vertical loads on the wetwell are shown. In particular, variation of hydrodynamic-generated vertical loads with changes in drywell-pressurization rate, downcomer submergence, and the vent-line loss coefficient are established. Initial drywell overpressure, which partially preclears the downcomers of water, substantially reduces the peak vertical loads. Scaling relationships, developed from dimensional analysis and verified by bench-top experiments, allow the 1 / 5 -scale results to be applied to a full-scale BWR power plant. This analysis leads to dimensionless groupings that are invariant. These groupings show that, if water is used as the working fluid, the magnitude of the forces in a scaled facility is reduced by the cube of the scale factor and occurs in a time reduced by the square root of the scale factor

  3. Treatment of Events Representing System Success in Accident Sequences in PSA Models with ET/FT Linking

    International Nuclear Information System (INIS)

    Vrbanic, I.; Spiler, J.; Mikulicic, V.; Simic, Z.

    2002-01-01

    Treatment of events that represent systems' successes in accident sequences is well known issue associated primarily with those PSA models that employ event tree / fault tree (ET / FT) linking technique. Even theoretically clear, practical implementation and usage creates for certain PSA models a number of difficulties regarding result correctness. Strict treatment of success-events would require consistent applying of de Morgan laws. However, there are several problems related to it. First, Boolean resolution of the overall model, such as the one representing occurrence of reactor core damage, becomes very challenging task if De Morgan rules are applied consistently at all levels. Even PSA tools of the newest generation have some problems with performing such a task in a reasonable time frame. The second potential issue is related to the presence of negated basic events in minimal cutsets. If all the basic events that result from strict applying of De Morgan rules are retained in presentation of minimal cutsets, their readability and interpretability may be impaired severely. It is also worth noting that the concept of a minimal cutset is tied to equipment failures, rather than to successes. For reasons like these, various simplifications are employed in PSA models and tools, when it comes to the treatment of success-events in the sequences. This paper provides a discussion of major concerns associated with the treatment of success-events in accident sequences of a typical PSA model. (author)

  4. 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)

  5. Nuclear accident dosimetry systems: U.K. measurements at the sixteenth intercomparison at O.R.N.L. August 1979

    International Nuclear Information System (INIS)

    Delafield, H.J.; Gibson, J.A.B.; Holt, P.D.; Harrison, K.G.

    1980-04-01

    The results are presented of the measurements made by the A.E.R.E., Harwell participants at the Intercomparison of Nuclear Accident Dosimetry Systems held at the Dosimetry Applications Research Facility (DOSAR) of the Oak Ridge National Laboratory, USA from 13 - 17 August 1979. The source of pulsed radiation used was the Health Physics Research Reactor which was operated bare for pulse 1, and shielded by concrete (20cm thickness) and steel (5cm thickness) for pulses 2 and 3 respectively. Measurements are reported which were made using personnel dosimeters (both in free-air and on phantoms) and a threshold detector system and compared with the provisional results given by the DOSAR group at the meeting. (U.K.)

  6. Cardiovascular system and physical working capacity in patients who had acute radiation syndrome as the result of Chernobyl accident

    International Nuclear Information System (INIS)

    Belyi, D.; Gergel, O.; Kovalenko, A.

    1996-01-01

    The functional state of cardiovascular system has been studied since 1986 in 168 patients who had acute radiation syndrome as the result of Chernobyl accident. There was revealed a progressive increase of cardiovascular system pathology. The number of patients with pathological signs at ECG increased from 4.8 % in 1987 to 11.3 % in 1994 and with myocardial hypertrophy from 1.2 % to 22.6 %. The number of patients with coronary heart disease increased on 17.2% and with essential hypertension on 15.5%. The physical working capacity reduced to 50-60 % of a due level for healthy persons. Two patients suffered from acute myocardial infarction during this period of observation. Thirteenth patients died from 1987 to 1995. Among them 4 patient died in a result of acute cardiac failure. The development of cardiovascular pathology has no any correlation with a dose of exposure. Three factors of cardiovascular pathology growth are supposed

  7. Functions and requirements for single-shell tank leakage mitigation

    International Nuclear Information System (INIS)

    Cruse, J.M.

    1994-01-01

    This document provides the initial functions and requirements for the leakage mitigation mission applicable to past and potential future leakage from the Hanford Site's 149 single-shell high-level waste tanks. This mission is a part of the overall mission of the Westinghouse Hanford Company Tank Waste Remediation System division to remediate the tank waste in a safe and acceptable manner. Systems engineering principles are being applied to this effort. A Mission Analysis has been completed, this document reflects the next step in the systems engineering approach to decompose the mission into primary functions and requirements. The functions and requirements in this document apply to mitigative actions to be taken regarding below ground leaks from SST containment boundaries and the resulting soil contamination. Leakage mitigation is invoked in the TWRS Program in three fourth level functions: (1) Store Waste, (2) Retrieve Waste, and (3) Disposition Excess Facilities

  8. Markovian Processes for Quantitative Information Leakage

    DEFF Research Database (Denmark)

    Biondi, Fabrizio

    Quantification of information leakage is a successful approach for evaluating the security of a system. It models the system to be analyzed as a channel with the secret as the input and an output as observable by the attacker as the output, and applies information theory to quantify the amount...... of information transmitted through such channel, thus effectively quantifying how many bits of the secret can be inferred by the attacker by analyzing the system’s output. Channels are usually encoded as matrices of conditional probabilities, known as channel matrices. Such matrices grow exponentially...... in the size of the secret and observables, are cumbersome to compute and store, encode both the behavior of the system and assumptions about the attacker, and assume an input-output behavior of the system. For these reasons we propose to model the systemattacker scenario with Markovian models. We show...

  9. Calculation of steam-gas mixture parameters in WWER-1000/V-320 containment during severe accident taking into account operation of filtered venting system

    International Nuclear Information System (INIS)

    Zvonarev, Yu.A.; Budaev, M.A.; Kobzar', V.L.; Konobeev, A.V.; Shmel'kov, Yu.B.

    2015-01-01

    The considered accident is a double-ended break of the cold leg with equivalent diameter of 850 mm accompanied with simultaneous total loss of power supply. The break is situated near the reactor inlet. No operator actions are assumed. Calculation analysis of the processes in reactor and containment were performed by SOKRAT V.1 and ANGAR codes. Containment of Unit № 4 Balakovo NPP was used for calculation of steam-gas mixture parameters in containment during severe accident. For specified algorithm of operating of filtered venting system, parameters of steam-gas mixture in containment and decay heat capacity of fission products retained by this system were defined [ru

  10. 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

  11. The Accident Analysis for Loss of Emergency Core Cooling System in Wolsong Unit 1 Using MARS-KS/CANDU

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinhyuck; Huh, Byunggil; Yang, Chaeyong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-05-15

    The deformation in the direction of the diameter of the pressure tube with the high-pressure and high-temperature can be done, and it is in direct contact with the calandria tube if deformation persisted. Once the contact occurs, the heat flux spike phenomenon occurs through the moderator of the low-temperature, which heat is rapidly removed. For the safety analysis of the accident without the emergency core cooling system, the development of modeling for a pressure tube and calandria tube contact and of heat removal load evaluation methodology of the moderator must be required. In this study, the purpose is to evaluate the heat removal load of the moderator with the pressure tube deformation model of MARS-KS-CANDU, which the emergency core cooling system damaged with a large break of the primary coolant system occurs. To analyze the LBLOCA with LOECC in CANDU type reactor, it is imperative to adequately predict the pressure tube deformation and subsequent heat removal load to the moderator. Therefore, in this study, we evaluate whether the pressure deformation model of MARS-KS-CANDU code is properly work through calculation of Wolsong Unit 1. It is estimated that pressure tube deformation model work properly and reliably predict the moderator's heat load in LOECC accident. However, these assessments should be limited for the qualitative part due to the difficulty of acquiring the experimental data for the CANDU type reactors. In future studies, the appropriate experimental data acquisition and the validation of the MARS-KSCANDU with those data should be required.

  12. Report on the water leakage from instrumentation pipe in JMTR

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    On December 10, 2002, the leakage was found at the pressure instrumentation pipe attached to the exit pipe of No.1 charging pump of the purification system of a primary cooling system at JMTR in the Oarai Research establishment, JAERI. The Investigation Committee for Water Leakage from Instrumentation Pipe in JMTR was established and organized by specialists from inside and outside JAERI on December 16 and its meeting was held in public 3 times by 6th January, 2003. They found out the cause and countermeasures of cracks, and also investigated enhancement of safety management. As the result, it was considered that the leakage started around the 6th of December 2002 and the cause of the cracks was due to fatigue by vibration of the charging pump during operation. The committee discovered following incorrect actions in the safety management. First, operation of JMTR was continued without keeping careful watch in spite of occurrence of leakage detector alarm. Second, every time when the alarm range for the reasons other than the leakage, appropriate investigation and countermeasure were not taken. Third, the manager in charge didn't have a fair understanding of the situation and didn't give an appropriate direction. This is the report on the cause and countermeasures of cracks and enhancement of safety management. (author)

  13. Effects of irradiation and design basis accident conditions on thermal properties of epoxy coating system for nuclear power plant

    International Nuclear Information System (INIS)

    Park, Soo-Jin; Seo, Min-Kang; Lee, Jae-Rock

    2004-01-01

    In this work, the thermal properties of epoxy coating system on carbon steel liner in an atomic reactor container have been investigated in terms of irradiation and design basis accident (DBA) conditions. Two epoxy coating systems were irradiated by different dose rates, i.e. 1x10 6 and 5x10 5 rad/h in a total dosage of 2x10 8 rad/h. And, DBA tests were applied to them based on the specification. The glass transition temperature (T g ) and thermal stability of the epoxy coating systems after tests were measured by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. As a result, the irradiation led to the fracture of internal structure in cured epoxy systems, resulting in significantly decreasing the thermal stability, as well as, the T g . Also, the higher dose rate made a relaxation of epoxy resins to reduce the hardening of the network system. Whereas, the DBA test made an important role in the thermal stability in the epoxy coating systems, resulting in post-curing of the uncured epoxy resins. Consequently, it could be found that the thermal properties of the epoxy coating system were greatly influenced on the irradiation and DBA tests, which were probably due to the modification of internal network structure of the epoxy resins

  14. 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

  15. Exploitation of Unintentional Information Leakage from Integrated Circuits

    Science.gov (United States)

    Cobb, William E.

    2011-01-01

    The information leakage of electronic devices, especially those used in cryptographic or other vital applications, represents a serious practical threat to secure systems. While physical implementation attacks have evolved rapidly over the last decade, relatively little work has been done to allow system designers to effectively counter the…

  16. Evaluation of isolation valve leakage in alternate charging piping

    International Nuclear Information System (INIS)

    Strauch, P.L.; Roarty, D.H.; Brice-Nash, R.L.

    1995-01-01

    The chemical and volume control system (CVCS) alternate charging flow path at an operating pressurized water reactor (PWR) plant was determined to be susceptible to adverse stresses from isolation valve leakage. Isolation valve leakage had resulted in pipe cracks at several nuclear units worldwide, as described in United States Nuclear Regulatory Commission Bulletin 88-08 and its supplements. To provide for continuing assurance that cracks would not initiate over the plant life, the operators considered performing fatigue evaluation to demonstrate structural integrity of the system. This evaluation included heat transfer, stress and fatigue analysis, using methods described in Electric Power Research Institute Report ''Thermal Stratification, Cycling, and Striping (TASCS),'' March 1994. The evaluation concluded that the fatigue usage would be less than 1.0 under worst case isolation valve leakage conditions, and therefore a significant investment in permanent temperature monitoring was avoided

  17. Benchmark calculations for evaluation methods of gas volumetric leakage rate

    International Nuclear Information System (INIS)

    Asano, R.; Aritomi, M.; Matsuzaki, M.

    1998-01-01

    A containment function of radioactive materials transport casks is essential for safe transportation to prevent the radioactive materials from being released into environment. Regulations such as IAEA standard determined the limit of radioactivity to be released. Since is not practical for the leakage tests to measure directly the radioactivity release from a package, as gas volumetric leakages rates are proposed in ANSI N14.5 and ISO standards. In our previous works, gas volumetric leakage rates for several kinds of gas from various leaks were measured and two evaluation methods, 'a simple evaluation method' and 'a strict evaluation method', were proposed based on the results. The simple evaluation method considers the friction loss of laminar flow with expansion effect. The strict evaluating method considers an exit loss in addition to the friction loss. In this study, four worked examples were completed for on assumed large spent fuel transport cask (Type B Package) with wet or dry capacity and at three transport conditions; normal transport with intact fuels or failed fuels, and an accident in transport. The standard leakage rates and criteria for two kinds of leak test were calculated for each example by each evaluation method. The following observations are made based upon the calculations and evaluations: the choked flow model of ANSI method greatly overestimates the criteria for tests ; the laminar flow models of both ANSI and ISO methods slightly overestimate the criteria for tests; the above two results are within the design margin for ordinary transport condition and all methods are useful for the evaluation; for severe condition such as failed fuel transportation, it should pay attention to apply a choked flow model of ANSI method. (authors)

  18. Experimental investigation on air leakage characteristics of containments

    International Nuclear Information System (INIS)

    Hyungtae Kim; Namso Cho; Youngsun Choun; Namsik Kim

    2005-01-01

    Facilities such as nuclear power plants have containments as atomic reactor which are subjected to high internal pressure. The internal pressure induces tensile stress in the containments. The tensile stress can cause generation and propagation of cracks through which the gas contaminated radioactively may leak. Supposing that a potential leakage accident happened, an experimental study on air leakage characteristics of containments was carried out. Two reinforced concrete specimens which reflect a wall of the containment were manufactured. Then the specimens were subjected to tensile load to generate cracks and air penetration tests were performed. During the air leakage test, the air pressure of inlet and outlet, the flow rate of outlet and the sum of crack widths were measured. The individual factors of the specific crack shape, the wall roughness and the flow coefficient, could be estimated from these experimental data. The factors are expressed as functions in terms of the sum of crack widths by regression analysis. The measured flow rates were compared with the predictive values obtained using the regression curves. Then flow rates according to pressure gradient and crack width were estimated. It was verified that the predicted flow rates agree with the measured flow rates statistically, that is, the estimated functions predicting the wall roughness and the flow coefficient are suitable. Once the sum of crack widths and inlet pressure of concrete wall are known, thus, the air flow rate can be predicted. The relationship among crack width, pressure and flow rate will serve as a criterion for air leakage characteristics of containments. (authors)

  19. Source term assessment, containment atmosphere control systems, and accident consequences. Report to CSNI by an OECD/NEA Group of experts

    International Nuclear Information System (INIS)

    1987-04-01

    CSNI Report 135 summarizes the results of the work performed by CSNI's Principal Working Group No. 4 on the Source Term and Environmental Consequences (PWG4) during the period extending from 1983 to 1986. This document contains the latest information on some important topics relating to source terms, accident consequence assessment, and containment atmospheric control systems. It consists of five parts: (1) a Foreword and Executive Summary prepared by PWG4's Chairman; (2) a Report on the Technical Status of the Source Term; (3) a Report on the Technical Status of Filtration and Containment Atmosphere Control Systems for Nuclear Reactors in the Event of a Severe Accident; (4) a Report on the Technical Status of Reactor Accident Consequence Assessment; (5) a list of members of PWG4

  20. Aerosol resuspension in the reactor cooling system of LWR's under severe accident conditions

    International Nuclear Information System (INIS)

    Alonso, A.; Bolado, R.; Hontanon, E.

    1991-07-01

    Aerosol resuspension from the pipes of the RCS under severe accident conditions happens when the carrier gas flow is turbulent. The origin of such phenomenon seems to be the existence of turbulent bursts in the neighbourhood of the pipe wall. These bursts are of random nature, in space and time. Three theoretical models have been found in available literature; those are: Cleaver and Yates', RESUS and Reeks' models. The first two of them are force balance models, in which particle detachment is supposed whenever aerodynamic lift or drag forces, respectively exceed adhesive forces, and the third one is an energy balance model in which resuspension happens when particle vibrational energy exceeds adhesive potential. From experimental evidence it seems that the studied phenomenon is a force balance problem and RESUS seems to be the most appropriate to it, among the available ones. Small-scale experiments have shown, as main parameters affecting resuspension, the Reynolds number of the flow, aerosol composition and initial loading per unit of area. Moreover, the resuspension rate decreases with time in all experiments where temporal measurements were taken

  1. DEFORM-4: fuel pin characterization and transient response in the SAS4A accident analysis code system

    International Nuclear Information System (INIS)

    Miles, K.J.; Hill, D.J.

    1986-01-01

    The DEFORM-4 module is the segment of the SAS4A Accident Analysis Code System that calculates the fuel pin characterization in response to a steady state irradiation history, thereby providing the initial conditions for the transient calculation. The various phenomena considered include fuel porosity migration, fission gas bubble induced swelling, fuel cracking and healing, fission gas release, cladding swelling, and the thermal-mechanical state of the fuel and cladding. In the transient state, the module continues the thermal-mechanical response calculation, including fuel melting and central cavity pressurization, until cladding failure is predicted and one of the failed fuel modules is initiated. Comparisons with experimental data have demonstrated the validity of the modeling approach

  2. Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology.

    Science.gov (United States)

    Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

    2017-01-01

    The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective sheathing of the pipe; this paper aims at testing the feasibility of detecting leakages with temporary introduced fiber optic cable inside the pipe. The detection and localization were tested in a laboratory experiment. The intrusion of water from leakages into the pipe, producing a local temperature drop, served as indicator for leakages. Measurements were taken under varying measurement conditions, including the number of leakages as well as the positioning of the fiber optic cable. Experiments showed that leakages could be detected accurately with the proposed methodology, when measuring resolution, temperature gradient and measurement time were properly selected. Despite the successful application of DTS for leakage detection in this lab environment, challenges in real system applications may arise from temperature gradients within the pipe system over longer distances and the placement of the cable into the real pipe system.

  3. 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)

  4. Leakage Resilient Secure Two-Party Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Hazay, Carmit; Patra, Arpita

    2012-01-01

    we initiate the study of {\\em secure two-party computation in the presence of leakage}, where on top of corrupting one of the parties the adversary obtains leakage from the content of the secret memory of the honest party. Our study involves the following contributions: \\BE \\item {\\em Security...... {\\em Leakage resilient oblivious transfer.} We present the first construction for 1-out-of-2 oblivious transfer with security against leakage of a constant fraction of the honest party's memory. Our protocol is based on the OT construction presented by Peikert et al.~\\cite{PeikertVW08}. \\item {\\em...... Leakage resilient Yao's Garbled Circuit~\\cite{Yao82}.} We provide the first general construction for secure two-party computation and show how to adapt the proof from~\\cite{LP09} of Yao's protocol into the leakage resilient setting. Our result holds for a restricted set of functions due to technicalities...

  5. Behavior of AC High Voltage Polyamide Insulators: Evolution of Leakage Current in Different Surface Conditions

    Directory of Open Access Journals (Sweden)

    Mohammed El Amine Slama

    2015-01-01

    Full Text Available This paper is aimed at a systematic study of the leakage current of high voltage polyamide insulator string under different conditions of pollution for possible application in the electric locomotive systems. It is shown that in the case of clean/dry and clean/wetted insulators, the leakage current and applied voltage are linear. While in the case of pollution with saline spray, the leakage current and the applied voltage are not linear; the leakage current changes from a linear regime to a nonlinear regime up to total flashover of the insulators sting. Traces of erosion and tracking of insulators resulting of partial discharges are observed.

  6. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository: accident event analysis and mechanical failure probabilities. Final report

    International Nuclear Information System (INIS)

    Bhaskaran, G.; McCleery, J.E.

    1979-10-01

    This report provides support in developing an accident prediction event tree diagram, with an analysis of the baseline design concept for the retrieval of emplaced spent unreprocessed fuel (SURF) contained in a degraded Canister. The report contains an evaluation check list, accident logic diagrams, accident event tables, fault trees/event trees and discussions of failure probabilities for the following subsystems as potential contributors to a failure: (a) Canister extraction, including the core and ram units; (b) Canister transfer at the hoist area; and (c) Canister hoisting. This report is the second volume of a series. It continues and expands upon the report Retrieval System for Emplaced Spent Unreprocessed Fuel (SURF) in Salt Bed Depository: Baseline Concept Criteria Specifications and Mechanical Failure Probabilities. This report draws upon the baseline conceptual specifications contained in the first report

  7. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository: accident event analysis and mechanical failure probabilities. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, G.; McCleery, J.E.

    1979-10-01

    This report provides support in developing an accident prediction event tree diagram, with an analysis of the baseline design concept for the retrieval of emplaced spent unreprocessed fuel (SURF) contained in a degraded Canister. The report contains an evaluation check list, accident logic diagrams, accident event tables, fault trees/event trees and discussions of failure probabilities for the following subsystems as potential contributors to a failure: (a) Canister extraction, including the core and ram units; (b) Canister transfer at the hoist area; and (c) Canister hoisting. This report is the second volume of a series. It continues and expands upon the report Retrieval System for Emplaced Spent Unreprocessed Fuel (SURF) in Salt Bed Depository: Baseline Concept Criteria Specifications and Mechanical Failure Probabilities. This report draws upon the baseline conceptual specifications contained in the first report.

  8. Practical Leakage-Resilient Symmetric Cryptography

    DEFF Research Database (Denmark)

    Faust, Sebastian; Pietrzak, Krzysztof; Schipper, Joachim

    2012-01-01

    construction may already suffice to protect against realistic side-channel attacks. In this paper, we show that indeed for simpler constructions leakage-resilience can be obtained when we aim for relaxed security notions where the leakage-functions and/or the inputs to the primitive are chosen non......-adaptively. For example, we show that a three round Feistel network instantiated with a leakage resilient PRF yields a leakage resilient PRP if the inputs are chosen non-adaptively (This complements the result of Dodis and Pietrzak [CRYPTO’10] who show that if a adaptive queries are allowed, a superlogarithmic number...

  9. Preliminary analysis of the inclusion of security passive systems to reduce the impact of accidents in nuclear power plants

    International Nuclear Information System (INIS)

    Sanchez J, J.; Morales S, J. B.; Espinosa P, G.

    2011-11-01

    In this work is presented a conceptual analysis of possible benefits and limitations that potentially represents the introduction of security passive systems to reduce the events impact of very low probability and high risk to the systems of radioactive material confinement of a light water reactor. These events are related with the possibility that a hydrogen explosion is presented as consequence of the accumulation of the same hydrogen in the contention of the reactor, in a scenario of severe accident. This accumulated hydrogen can be liberated in the reactor building or primary contention, where the conditions of their atmosphere make but prone the combustion. The catalytic recombination represents a viable option for the hydrogen concentrations decrease and because this recombination is highly exothermic, is important to analyze and to know if the recombined vapor to high temperature can be used in combination with vapor injectors that in turn, they are passive systems. In the following sections an explanation is presented about the use of the mentioned systems, as well as some results on the behavior of the vapor injectors. (Author)

  10. Corporate Cost of Occupational Accidents

    DEFF Research Database (Denmark)

    Rikhardsson, Pall M.; Impgaard, M.

    2004-01-01

    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...... 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...

  11. The state of immune system in children of participants of Chornobyl accident clean-up at the final state of sexual maturation

    International Nuclear Information System (INIS)

    Shlyakhova, N.V.

    2009-01-01

    The changes in the immune system involving all links of the immunity are three times more frequent in children whose fathers participated in Chornobyl accident clean-up. Disorders of humoral and phagocyte links are gender-dependent. Significant difference in the level of immunological parameters depending on the year of the father's stay in the zone was not revealed.

  12. The functional state of the cardiovascular system in adolescents aged 16-18 born from the parents who participated in Chornobyl accident clean-up

    International Nuclear Information System (INIS)

    Korenjev, M.M.; Kostenko, T.O.; Borisko, G.O.; Kalmikova, N.V.; Cherevatova, S. Kh.; Bondarenko, V.L.

    2010-01-01

    The state of the cardiovascular system of the adolescents aged 16-18 born from the parents who participated in Chornobyl accident clean-up was characterized by a high incidence of myocardium bioelectric activity disorders, presence of congenital small heart defects, widening of the left ventricle cavity, reduction of contractile function and myocardium tolerance to physical load.

  13. Preliminary H{sub 2} Combustion Analysis in the Containment of APR1400 for SBLOCA Accident using a Multi-Dimensional H{sub 2} Analysis System

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyung Seok; Kim, Jongtae; Kim, Sang-Baik; Hong, Seong-Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The COM3D analyze an overpressure buildup resulting from a propagation of hydrogen flame along the structure and wall in the containment using the hydrogen distribution result calculated by the GASFLOW. The MAAP evaluates a hydrogen source during a severe accident and transfer it to the GASFLOW. We performed a hydrogen combustion analysis using the multidimensional hydrogen analysis system for a station blackout (SBO) accident under the assumption of 100% metal-water reaction in the reactor vessel. The COM3D results showed that the pressure buildup was about 250 kPa because the flame speed was not increased above 300 m/s and the pressure wave passed through the open spaces in the large containment. To increase the reliability of the COM3D calculation, it is necessary to perform the hydrogen combustion analysis for another accident such as a small break loss of coolant (SBLOCA). KAERI performed a hydrogen combustion analysis for a SBLOCA accident using the multi-dimensional hydrogen analysis system under the assumption of 100% metal-water reaction in the reactor vessel. From the COM3D results, we can know that the pressure buildup was approximately 310 kPa because the flame speed was not increased above 100 m/s owing to the high steam concentration and low oxygen concentration in the hydrogen distributed region of the containment. The predicted maximum overpressure in the SBLOCA accident is similar to that of the COM3D results for the SBO accident. Thus, we found that the maximum overpressure due to the hydrogen combustion in the containment may depend on the amount of hydrogen mass released from the reactor vessel.

  14. 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

  15. Investigations of leakage mechanisms and its influences on a micro swing engine considering rarefaction effects

    International Nuclear Information System (INIS)

    Zhou, Xiong; Zhang, Zhenyu; Kong, Wenjun; Du, Ning

    2016-01-01

    Highlights: • Mechanisms of the leakage flow in different flow regimes have been studied. • The leakage flow regime and patterns in the micro swing engine are presented. • Slip on the walls has a larger effect on leakage flow with decreasing the gap. • Rarefaction effects on the engine performance have been investigated. - Abstract: Considering rarefaction effects, this paper investigated mechanisms of the clearance leakage and its influences on a micro swing engine for the micro power generation by employing three different flow models named as discrete velocity direction (DVD) model, Navier-Stokes equations with slip boundary conditions (NS-slip) and no-slip boundary conditions (NS-no slip). Using the DVD model, this paper firstly studied leakage mechanisms of a micro Couette-Poisueille flow. Factors which control the leakage in different regimes were obtained. Furthermore, the system-level predictions of the clearance leakage in the micro swing engine have been conducted by solving the Navier-Stokes equations. The leakage flow regime, patterns and characteristics were presented. Results by NS-slip and NS-no slip were compared to study the rarefaction effects. Finally, investigations of the engine size and the gap height on the engine performance have been conducted. The significance of the leakage in different engine size regimes was presented, and the results show that rarefaction effects affect the indicated thermal efficiency greatly with the decrease of the engine size scale.

  16. Effect of Occupational Health and Safety Management System on Work-Related Accident Rate and Differences of Occupational Health and Safety Management System Awareness between Managers in South Korea's Construction Industry

    OpenAIRE

    Seok J. Yoon; Hsing K. Lin; Gang Chen; Shinjea Yi; Jeawook Choi; Zhenhua Rui

    2013-01-01

    Background: The study was conducted to investigate the current status of the occupational health and safety management system (OHSMS) in the construction industry and the effect of OHSMS on accident rates. Differences of awareness levels on safety issues among site general managers and occupational health and safety (OHS) managers are identified through surveys. Methods: The accident rates for the OHSMS-certified construction companies from 2006 to 2011, when the construction OHSMS became ...

  17. Aftereffect Calculation and Prediction of Methanol Tank Leak’s Environmental Risk Accident

    Science.gov (United States)

    Lang, Yueting; Zheng, Lina; Chen, Henan; Wang, Qiushi; Jiang, Hui; Pan, Yiwen

    2018-01-01

    With the increasing frequency of environmental risk accidents, more emphasis was placed on environmental risk assessment. In this article, the aftermath of an Environmental Risk Accident on Methanol Tank Leakage occurred on a cryogenic unit area in a certain oilfield processing plant have been mainly calculated and predicted. Major hazards were identified through the major hazards identification on dangerous chemicals, which could afterwards analyze maximum credible accident and confirm source item and the source intensity. In the end, the consequence of the accident has been calculated so that the impact on surrounding environment can be predicted after the accident.

  18. Leakage-resilient cryptography from minimal assumptions

    DEFF Research Database (Denmark)

    Hazay, Carmit; López-Alt, Adriana; Wee, Hoeteck

    2013-01-01

    We present new constructions of leakage-resilient cryptosystems, which remain provably secure even if the attacker learns some arbitrary partial information about their internal secret key. For any polynomial ℓ, we can instantiate these schemes so as to tolerate up to ℓ bits of leakage. While the...

  19. Predicting Envelope Leakage in Attached Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, O.; Arena, L.; Griffiths, D.

    2013-07-01

    The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, and control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.

  20. Analysis of a simulated small break in the semiscale system under loss-of-coolant accident conditions

    International Nuclear Information System (INIS)

    Cartmill, C.E.

    1978-01-01

    The Semiscale Mod-1 experimental program conducted by EG and G Idaho, Inc., is part of the overall U.S. Nuclear Regulatory Commission (NRC) and Department of Energy (DOE) sponsored research and development program to investigate the behavior of the pressurized water reactor (PWR) system during an hypothesized loss-of-coolant accident (LOCA). The Semiscale Mod-1 program is intended to provide transient thermal-hydraulic data from a simulated LOCA using a small-scale experimental nonnuclear system. The Semiscale Mod-1 program is a major contributor of experimental data that provide a means of evaluating the adequacy of overall system analytical models as well as the models of the individual system components. Selected experimental data produced by this program will also be used to aid other DOE and NRC sponsored experimental programs, such as the Loss-of-Fluid Test (LOFT) program in optimizing test series, selecting test parameters, and evaluating test results. The Semiscale Mod-1 tests are performed with an experimental system which simulates the principal features of a nuclear plant but which is smaller in volume. Nuclear heating is simulated in the tests by a core composed of an array of electrically heated rods. The core is contained in a pressure vessel which also includes a downcomer, lower plenum, and upper plenum. The Semiscale system piping is arranged such that the intact loop represents three loops of a four-loop nuclear plant, and the broken loop represents the fourth loop. In the present configuration the intact loop contains an active steam generator and pump, and the broken loop contains passive simulators for the steam generator and pump

  1. Leakage-Resilient Circuits without Computational Assumptions

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2012-01-01

    Physical cryptographic devices inadvertently leak information through numerous side-channels. Such leakage is exploited by so-called side-channel attacks, which often allow for a complete security breache. A recent trend in cryptography is to propose formal models to incorporate leakage...... into the model and to construct schemes that are provably secure within them. We design a general compiler that transforms any cryptographic scheme, e.g., a block-cipher, into a functionally equivalent scheme which is resilient to any continual leakage provided that the following three requirements are satisfied......: (i) in each observation the leakage is bounded, (ii) different parts of the computation leak independently, and (iii) the randomness that is used for certain operations comes from a simple (non-uniform) distribution. In contrast to earlier work on leakage resilient circuit compilers, which relied...

  2. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    of this thesis was to: Clarify the best suited animal to model clinical anastomotic leakage in humans; Create animal models mimicking anastomotic leakage in humans induced by insufficient surgical technique and tissue ischemia; Determine the best suited coating materials to prevent anastomotic leakage. STUDY 1......, ischemia and insufficient surgical technique have been suggested to play a central role. Animal models are valuable means to evaluate pathophysiological mechanisms and may be used to test preventive measures aiming at reducing the risk of anastomotic leakage, such as external anastomotic coating. The aim...... of experimental animals were identified. The results indicated that the mouse and the pig are the best suited animals to evaluate clinical anastomotic leakage. However, the pig model is less validated and more costly to use compared with the mouse. Most frequently, rats are used as models. However, extreme...

  3. Isotope distributions in primary heat transport and containment systems during a severe accident in CANDU type reactor

    International Nuclear Information System (INIS)

    Constantin, M.

    2005-01-01

    The paper is intended to analyse the distribution of the fission products (FPs) in CANDU Primary Heat Transport (PHT) and CANDU Containment Systems by using the ASTEC code. The complexity of the data required by ASTEC and the complexity both of CANDU PHT and Containment System were strong motivation to begin with a simplified model. The data related to the nodes' definitions, temperatures and pressure conditions were chosen as possible as real data from CANDU loss of coolant accident sequence (CATHENA code results). The source term of FPs introduced into the PHT was estimated by ORIGEN code. The FPs distribution in the nodes of the circuit and the FPs mass transfer per isotope and chemical species were obtained by using SOPHAEROS module. The distributions within the containment are obtained by the CPA module (thermalhydraulic calculations in the containment and FPs aerosol transport). The results consist of mass distributions in the nodes of the circuit and the transferred mass to the containment through the break for different species (FPs and chemical species) and mass distributions in the different parts of the containment and different hosts. (authors)

  4. Development of computer-controlled ultrasonic image processing system for severe accidents research

    International Nuclear Information System (INIS)

    Koo, Kil Mo; Kang, Kyung Ho; Kim, Jong Tai; Kim, Jong Whan; Cho, Young Ro; Ha, Kwang Soon; Park, Rae Jun; Kim, Sang Baik; Kim, Hee Dong; Sim, Chul Moo

    2000-07-01

    In order to verify in-vessel corium cooling mechanism, LAVA(Lower-plenum Arrested Vessel Attack) experiment is being performed as a first stage proof of principle test. The aims of this study are to find a gap formation between corium melt and reactor lower head vessel, to verify the principle of the gap formation and to analyze the effect of the gap formation on the thermal behavior of corium melt and the lower plenum. This report aims at developing a computer controlled image signal processing system which is able to improve visualization and to measure the gap distribution with 3-dimensional planar image using a time domain signal analysis method as a part of the ultrasonic pulse echo methods and a computerized position control system. An image signal processing system is developed by independently developing an ultrasonic image signal processing technique and a PC controlled position control system and then combining both systems

  5. Development of computer-controlled ultrasonic image processing system for severe accidents research

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Kil Mo; Kang, Kyung Ho; Kim, Jong Tai; Kim, Jong Whan; Cho, Young Ro; Ha, Kwang Soon; Park, Rae Jun; Kim, Sang Baik; Kim, Hee Dong; Sim, Chul Moo

    2000-07-01

    In order to verify in-vessel corium cooling mechanism, LAVA(Lower-plenum Arrested Vessel Attack) experiment is being performed as a first stage proof of principle test. The aims of this study are to find a gap formation between corium melt and reactor lower head vessel, to verify the principle of the gap formation and to analyze the effect of the gap formation on the thermal behavior of corium melt and the lower plenum. This report aims at developing a computer controlled image signal processing system which is able to improve visualization and to measure the gap distribution with 3-dimensional planar image using a time domain signal analysis method as a part of the ultrasonic pulse echo methods and a computerized position control system. An image signal processing system is developed by independently developing an ultrasonic image signal processing technique and a PC controlled position control system and then combining both systems.

  6. Response of the SPND measurement system to temperature during the Three Mile Island Unit 2 accident. [Self-Powered Neutron Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, N.; Morrison, J.L. Jr.

    1981-12-01

    The Self-Powered Neutron Detector (SPND) Measuring System is evaluated to determine its ability to indicate temperatures of the fuel rods in the TMI-2 reactor core during the accident. It is concluded for the following reasons that the SPND Measuring System did not provide fuel rod temperatures during the accident: the heat transfer characteristics vary over a range of five octaves; within the range of 1200 to 1800/sup 0/F, the SPND responds to temperature from convection radiation from the fuel rods and self-heating from the gamma flux; within the range of 1200 to 1800/sup 0/F, the signal cable introduces masking signals that are a function of gamma heating, integrated temperature over the cable, and core water level velocity; the data system's worst-case signal-to-noise ratio from aliasing is 0dB; and the recorder system's worst-case signal-to-noise ratio from aliasing is -24dB.

  7. Source term analysis for a nuclear submarine accident

    International Nuclear Information System (INIS)

    Lewis, B.J.; Hugron, J.J.M.R.

    1999-01-01

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

  8. 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....

  9. FRANTIC-NRC, Accident Sequence and Event Tree Analysis for System Availability and Operation

    International Nuclear Information System (INIS)

    Ginzburg, T.

    1988-01-01

    1 - Description of problem or function: FRANTIC3 was developed to evaluate system unreliability using time-dependent techniques. The code provides two major options: to evaluate standby system unavailability or, in addition to the unavailability, to calculate the total system failure probability by including both the unavailability of the system on demand as well as the probability that it will operate for an arbitrary time period following the demand. The FRANTIC time-dependent reliability models provide a large selection of repair and testing policies applicable to standby or continuously operating systems consisting of periodically tested, monitored, and non-repairable (non-testable) components. Time- dependent and test frequency dependent failures, as well as demand stress related failure, test-caused degradation and wear-out, test associated human errors, test deficiencies, test override, unscheduled and scheduled maintenance, component renewal and replacement policies, and test strategies can be prescribed. The conditional system unavailabilities associated with the downtimes of the user specified failed component are also evaluated. Optionally, the code can perform a sensitivity study for system unavailability or total failure probability to the failure characteristics of the standby components. 2 - Method of solution: FRANTIC3 uses a set of analytical equations for component unavailabilities and failure intensities with exponential and Weibull time distributions for constant test and duration times. The FRANTIC code determines the state (test, repair, or between test) of each component at each time point and selects the appropriate component unavailability model depending on the state. Using the appropriate logical relationships among the unavailabilities of individual components, the system unavailability (or total failure probability) is also calculated at these time points. Then, the system average unavailability (or total failure probability) is

  10. User requirements for decision support systems used for nuclear power plant accident prevention and mitigation

    International Nuclear Information System (INIS)

    1989-10-01

    One limitation of existing information support systems is that the 'end user' (i.e., decision maker) is not properly accounted for in these systems. Therefore, it is needed to consider how the information to be provided by the system is going to be used and to recognize the cognitive decision making process. To discuss how to consider the end user as an integral part of decision support systems (DSS) a Technical Committee Meeting on 'User's Requirements for DSS' was organized by the IAEA in Vienna from 28 November - 1 December 1988. The meeting was attended by 45 participants from 22 countries and international organizations. Sixteen papers have been presented in three technical sessions, which addressed the following areas: Problem identification; design of DSS; user's considerations in DSSs. A separate abstract was prepared for each of these papers. Refs, figs and tabs

  11. Development of intergrated accident management assessment technology; development of interface modules of risk-monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. K.; Park, S. K.; Seok, H.; Kim, D. K.; Han, J. K.; Park, B. R. [KOPEC, Taejeon (Korea)

    2002-03-01

    Based on the development of interface modules with FORTE.- DynaRM can quantify risk model very fast (Very frequent risk model quantification is needed for configuration risk management).- risk monitoring system technology transfer to foreign NPPs. Contribution to component failure and maintenance control automation with the development of Tagging control System. On-Line risk monitoring system development by joint team between Korea Atomic Energy Research Institute and KOPEC is a request by KEPCO. The softwares developed in this study is easily implemented at domestic NPPs without extra study or cost. Economic benefit and Software export to foreign NPPs are expected because of the development of technology related to risk monitoring system and its management. 6 refs., 3 figs., 1 tab. (Author)

  12. Noble gas removal system for post-accident decontamination of power reactors

    International Nuclear Information System (INIS)

    Stephenson, M.J.; Kanak, B.E.; Little, D.K.; Merriman, J.R.; Riepe, R.C.

    1980-05-01

    Oak Ridge has developed a noble gas removal system, as part of the Consolidated Fuel Reprocessing Program, that could be used to help decontaminate the containment vessel of a power reactor following core release of fission gas in the event that containment venting is judged to be unacceptable. The system is based on a fluorocarbon selective absorption process, which has been well demonstrated on an engineering scale with over 10 years of pilot plant operation

  13. Death of a 23-year-old man from cardiac conduction system injury through a blunt chest impact after a car accident

    Directory of Open Access Journals (Sweden)

    S. Zerbo

    2014-12-01

    The authors report a case of death due to a cardiac conduction system injury from a blunt chest impact following a car accident. The autopsy showed no external signs of thoracic trauma, no evident rib or sternum fractures. A small sub-endocardial hemorrhage was found in the region of the atrioventricular node. Histological examination revealed an injury of the atrioventricular node and His’ bundle. The cause of the death was attributed to the arrhythmia induced by contusion of the cardiac conduction system.

  14. General principles taken into account in France for the use of systems in the operating documents for accidental situations (including severe accidents) on PWR plants

    International Nuclear Information System (INIS)

    Guieu, S.; Soldermann, R.

    1991-01-01

    The paper describes the scope of operating documents with allowance for the division of operating conditions into the following main fields: design basis operating conditions, complementary operating conditions, operating conditions not considered as being plausible. General approach to the choice of systems to be used for an accidental situation and the severe accident action guide, providing the operator with a definition of specific actions, are discussed, as well as checking the appropriateness of the systems used

  15. 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

  16. Leakage of caesium braquitherapy sources

    International Nuclear Information System (INIS)

    Lozada, J.A.

    1998-01-01

    In several Venezuelan public hospitals where cervix uteri tumours are treated by intracavitary radiotherapy, that use manual after loading Fletcher method, with Caesium 137 sources, the use of improper source holders, locally manufactured from pieces of drainage plastic tubing, which deteriorated and created a corrosive environment all around the sources, omission of manufacturer's recommendations regarding corrosion information, source storage, inspection and testing, violation of International Atomic Energy Agency Radiation Protection Procedures, and lack of proper regulatory control, resulted integrity damage to about sixty special form sources (ISO2919 C 63322), leakage of Cs-137 from a supposed insoluble refractory active content (caesium silicoaluminate), and contamination of applicators, floors and bedding. When the situation was detected by means removal contamination tests, after routine inspections, the sources were removed from the hospitals, decontaminated by means of immersion in 3% EDTA solution in ultrasonic bath, subjected to leaking assessment tests, and the ones that passed were placed in low cost stainless steel source holders, designed and built by the instituto Venezolano de Investigaciones Cientificas (IVIC) returned to the hospitals. The leaking sources were removed from use and considered radioactive waste. In order to avoid the occurrence of similar situations, all the importers of such sources are now required to send them to IVIC for testing and placement in proper source holders, before they are shipped to the hospitals. (author)

  17. S.RES. 455: resolution to call for the creation of an early notification system for nuclear accidents. Introduced in the Senate of the United States, Ninety-Congress, Second Session, July 28, 1986

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The resolution calls for the creation of an early notification system for nuclear accidents. It is a response to the Chernobyl nuclear power station accident in the Soviet Union, and reflects international concern over the time that passed before warnings and information were made public

  18. Radiation Measurement Systems and Experiences in Japan after the Fukushima Accident

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    In the approximately 4 years since the March 2011 earthquake and subsequent Tsunami damaged the three Dai-Ichi nuclear power plants, the AREVA and Canberra team have deployed a variety of different radiation measurement machines in Japan. These measurement projects or instruments include: - Dose-rate mapping of the close-in areas on the damaged reactor site using the stored output of dose rate meters carried by workers planning for the installing of a water processing unit; - Spectroscopic on-line measurements of the first water processing unit on the site, where these nuclide-specific measurements at multiple points allowed remote users to determine the optimum processing parameters - General purpose food measurement units, both high precision HPGe systems and low cost NaI systems, which were used throughout the country for food quality measurements; - In-vivo measurement systems, both fixed and mobile whole body counting units, that were used on at least 500,000 people, demonstrating to them that internal doses were very low; - In-vivo measurements with special high-sensitivity whole body counters on babies and children, demonstrating to the parents of these children that internal doses are very low; - Automatic systems for high throughput assay of bags of rice that are part of the consumer confidence plan to prove to customers that Fukushima Prefecture rice is safe; - High sensitivity automatic system to assay boxes of special semi-dry persimmons and to report the activity of each individual item within the box meets the regulatory limit; - System to assay soil on a conveyor belt and sort the output according to level of radioactivity, which would then reduce the volume of material that must be treated as radioactive; - System to assay a truck loaded with 1 cubic meter sacks of soil and vegetation, and report the results of each individual sack. - On-line water measurement system for SrY90 at levels that are suitable for release to the environment; - Mobile

  19. Radiation Measurement Systems and Experiences in Japan after the Fukushima Accident

    International Nuclear Information System (INIS)

    2015-01-01

    In the approximately 4 years since the March 2011 earthquake and subsequent Tsunami damaged the three Dai-Ichi nuclear power plants, the AREVA and Canberra team have deployed a variety of different radiation measurement machines in Japan. These measurement projects or instruments include: - Dose-rate mapping of the close-in areas on the damaged reactor site using the stored output of dose rate meters carried by workers planning for the installing of a water processing unit; - Spectroscopic on-line measurements of the first water processing unit on the site, where these nuclide-specific measurements at multiple points allowed remote users to determine the optimum processing parameters - General purpose food measurement units, both high precision HPGe systems and low cost NaI systems, which were used throughout the country for food quality measurements; - In-vivo measurement systems, both fixed and mobile whole body counting units, that were used on at least 500,000 people, demonstrating to them that internal doses were very low; - In-vivo measurements with special high-sensitivity whole body counters on babies and children, demonstrating to the parents of these children that internal doses are very low; - Automatic systems for high throughput assay of bags of rice that are part of the consumer confidence plan to prove to customers that Fukushima Prefecture rice is safe; - High sensitivity automatic system to assay boxes of special semi-dry persimmons and to report the activity of each individual item within the box meets the regulatory limit; - System to assay soil on a conveyor belt and sort the output according to level of radioactivity, which would then reduce the volume of material that must be treated as radioactive; - System to assay a truck loaded with 1 cubic meter sacks of soil and vegetation, and report the results of each individual sack. - On-line water measurement system for SrY90 at levels that are suitable for release to the environment; - Mobile

  20. An international co-ordinated research programme on nuclear accident dosimetry

    International Nuclear Information System (INIS)

    Flakus, F.N.

    1977-01-01

    Where fissile materials are being processed in quantities exceeding the minimum critical amounts, a radiation risk to workers arises from the possibility of criticality excursions. Despite the fact that techniques for preventing the occurende of such accidental excursions have reached very high standards it is generally agreed that the availability of suitable nuclear accident dosimetry (NAD) systems is very important. Following the recommendations of an Advisory Group meeting on NAD, the IAEA had established in 1969 an international coordinated research programme on NAD systems and elaborating standarized systems. A large number of research groups from 14 Member States throughout the world participated in this co-ordinated work. Since 1970 four international multilaboratory intercomparison experiments on NAD have been organized and the response of a variety of dosimeters examined in different neutron spectra under simulated accident conditions at Valduc (France), Oak Ridge (USA), Vinca (Yugoslavia) and Harwell (UK). The results achieved in these intercomparison studies show that NAD systems have been substantially improved and that several systems are available now in a number of laboratories throughout the world that perform within the criteria laid down by the initiating advisory group in 1969. A compendium of neutron leakage spectra has also been elaborated for facilitating the determination of dose from readings of detectors exposed to various neutron fields in criticality accidents

  1. Human factors study of driver assistance systems to reduce lane departures and side collision accidents.

    Science.gov (United States)

    2008-07-01

    This study investigated the human factors issues related to the implementation of lane departure warning systems (LDWS) to reduce side collision and run-off-road crashes for heavy trucks. Lane departures can be either intentional (e.g., to pass anoth...

  2. Quality assurance and verification of the MACCS [MELCOR Accident Consequence Code System] code, Version 1.5

    International Nuclear Information System (INIS)

    Dobbe, C.A.; Carlson, E.R.; Marshall, N.H.; Marwil, E.S.; Tolli, J.E.

    1990-02-01

    An independent quality assurance (QA) and verification of Version 1.5 of the MELCOR Accident Consequence Code System (MACCS) was performed. The QA and verification involved examination of the code and associated documentation for consistent and correct implementation of the models in an error-free FORTRAN computer code. The QA and verification was not intended to determine either the adequacy or appropriateness of the models that are used MACCS 1.5. The reviews uncovered errors which were fixed by the SNL MACCS code development staff prior to the release of MACCS 1.5. Some difficulties related to documentation improvement and code restructuring are also presented. The QA and verification process concluded that Version 1.5 of the MACCS code, within the scope and limitations process concluded that Version 1.5 of the MACCS code, within the scope and limitations of the models implemented in the code is essentially error free and ready for widespread use. 15 refs., 11 tabs

  3. Real-time management (RTM) by cloud computing system dynamics (CCSD) for risk analysis of Fukushima nuclear power plant (NPP) accident

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyo Sung [Yonsei Univ., Wonju Gangwon-do (Korea, Republic of). Dept. of Radiation Convergence Engineering; Woo, Tae Ho [Yonsei Univ., Wonju Gangwon-do (Korea, Republic of). Dept. of Radiation Convergence Engineering; The Cyber Univ. of Korea, Seoul (Korea, Republic of). Dept. of Mechanical and Control Engineering

    2017-03-15

    The earthquake and tsunami induced accident of nuclear power plant (NPP) in Fukushima disaster is investigated by the real-time management (RTM) method. This non-linear logic of the safety management is applied to enhance the methodological confidence in the NPP reliability. The case study of the earthquake is modeled for the fast reaction characteristics of the RTM. The system dynamics (SD) modeling simulations and cloud computing are applied for the RTM method where the real time simulation has the fast and effective communication for the accident remediation and prevention. Current tablet computing system can improve the safety standard of the NPP. Finally, the procedure of the cloud computing system dynamics (CCSD) modeling is constructed.

  4. Best Estimate Thermal-Hydraulic System Analysis using the MARS Code for the Steam Generator Tube Rupture Accident in the APR1400

    International Nuclear Information System (INIS)

    Kang, Kyoung Ho; Lee, Seung Wook; Bae, Sung Won; Choi, Ki Yong; Baek, Won Pil

    2010-01-01

    A postulated SGTR (Steam Generator Tube Rupture) accident of the APR1400 was analysed using the best estimate safety analysis code, MARS (Multidimensional Analysis of Reactor Safety). The SGTR accident is one of the design basis accidents, which has a unique feature of the penetration of the barrier between the reactor coolant system (RCS) and the secondary system resulting from the failure of a steam generator U-tube. The SGTR has an importance in safety due to a concern of a containment bypass of radioactive inventory. In the course of the SGTR, the radioactivity leaking from a broken steam generator Utube mixes with the shell-side water in an affected steam generator. Leak flow from ruptured U-tubes can increase a water level and a pressure of the affected steam generator. Following a reactor trip and a turbine trip, the main steam safety valves (MSSVs) can be open to mitigate an increase in the secondary system pressure. Meanwhile, the SGTR can provide a direct flow path from the primary to the secondary system resulting in the release of fission products into the atmosphere. As one of the most limiting SGTR accidents, a leak flow equivalent to a double-ended rupture of five Utubes was analysed in this study. The main objective of this study is not only to provide physical insight into the system response of the APR1400 reactor during a SGTR but also to investigate the effect of reactor trip type of the HSGL (High Steam Generator Level) trip and the LPP (Low Pressurizer Pressure) trip on the thermal-hydraulic system response

  5. ADASIR system: a Cuban learning experience from accidents and promotion of radiation safety culture

    International Nuclear Information System (INIS)

    Ferro Fernandez, Ruben; Ilizastigui Perez, Fidel; Fuente Puch, Andres de la

    2010-01-01

    The Cuban Regulatory Authority is carrying out a National Program for fostering and development of Safety Culture taking into account the wide recognition of the Human factors contribution to radiological events. The program includes the introduction of new regulatory practices and initiatives in order to increase the safety culture in Cuban facilities. The most recent of those initiatives is the System for Radiological Event Analysis, Dissemination and Learning, called ADASIR (Initials of the System's name in Spanish). The main purpose of this system is to provide a better understanding and knowledge of any radiological event reported both in the country and abroad reducing, this way, the possibility of a new occurrence of a similar event in our facilities. A team of regulatory and external experts make together a detailed review of all available information about the event and identify possible root causes, failed barriers and other important data of national interest. The results of such review are documented and sent to any Cuban facility or organization with potential for similar occurrence according to the equipment and practices they have. The document includes an specific checklist which could be used by the facilities to make a self-assessment and evaluate theirs strength and weakness in regards to a similar event. This paper presents the main characteristics and results of this new experience of Cuban Regulatory Authority. (author)

  6. Severe accident testing of electrical penetration assemblies

    International Nuclear Information System (INIS)

    Clauss, D.B.

    1989-11-01

    This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs

  7. Leakage detection algorithm integrating water distribution networks hydraulic model

    CSIR Research Space (South Africa)

    Adedeji, K

    2017-06-01

    Full Text Available and estimation is vital for effective water service. For effective detection of background leakages, a hydraulic analysis of flow characteristics in water piping networks is indispensable for appraising such type of leakage. A leakage detection algorithm...

  8. Method to detect steam generator tube leakage

    International Nuclear Information System (INIS)

    Watabe, Kiyomi

    1994-01-01

    It is important for plant operation to detect minor leakages from the steam generator tube at an early stage, thus, leakage detection has been performed using a condenser air ejector gas monitor and a steam generator blow down monitor, etc. In this study highly-sensitive main steam line monitors have been developed in order to identify leakages in the steam generator more quickly and accurately. The performance of the monitors was verified and the demonstration test at the actual plant was conducted for their intended application to the plants. (author)

  9. VISUAL INSPECTION OF WATER LEAKAGE FROM GROUND PENETRATING RADAR RADARGRAM

    Directory of Open Access Journals (Sweden)

    N. N. Halimshah

    2015-10-01

    Full Text Available Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  10. Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  11. Effect of Surface Treatments on Leakage of Zirconium Oxide Ceramics

    Directory of Open Access Journals (Sweden)

    Göknil Alkan Demetoğlu

    2016-08-01

    Full Text Available Objective: The aim of this pilot study was to compare the effects of pretreatments on leakage of zirconia ceramics. Materials and Methods: The speciments divided into 6 groups that were subsequently treated as follows: group 1, no treatment (control; group 2, the ceramic surfaces were airborne-particle abraded with 110 μm aluminum-oxide (Al2O3 particles; group 3, after abrasion of the surfaces with 110 μm Al2O3 particles, silica coating using 30 μm (Al2O3 particles modified by silica (rocatec system and application of the silane coupling agent (espe-sil; group 4, ceramic surfaces irritated with neodymium-doped yttrium aluminium garnet (Nd:YAG laser [fidelis plus 3 foton (Ljubljana, Slovenia] at 20 hz, 100 mj, 2 w, 100 μs; group 5, ceramic surfaces irritated with Nd:YAG laser at fidelis plus 3 fotona (Ljubljana, Slovenia at 20 hz, 100 mj, 2 w, 100 μs; group 6; application of a zirconia primer (z-prime plus bisco, IL, USA agent. And all ceramics tested for leakage. Results: For marginal leakage, score 0 was found in all groups. Conclusion: No significant differences were found in marginal leakage under all conditions.

  12. Strategy generation in accident management support

    International Nuclear Information System (INIS)

    Sirola, M.

    1995-01-01

    An increased interest for research in the field of Accident Management can be noted. Several international programmes have been started in order to be able to understand the basic physical and chemical phenomena in accident conditions. A feasibility study has shown that it would be possible to design and develop a computerized support system for plant staff in accident situations. To achieve this goal the Halden Project has initiated a research programme on Computerized Accident Management Support (CAMS project). The aim is to utilize the capabilities of computerized tools to support the plant staff during the various accident stages. The system will include identification of the accident state, assessment of the future development of the accident and planning of accident mitigation strategies. A prototype is developed to support operators and the Technical Support Centre in decision making during serious accident in nuclear power plants. A rule based system has been built to take care of the strategy generation. This system assists plant personnel in planning control proposals and mitigation strategies from normal operation to severe accident conditions. The ideal of a safety objective tree and knowledge from the emergency procedures have been used. Future prediction requires good state identification of the plant status and some knowledge about the history of some critical variables. The information needs to be validated as well. Accurate calculations in simulators and a large database including all important information form the plant will help the strategy planning. (author). 12 refs, 2 figs

  13. A new approach to modeling aviation accidents

    Science.gov (United States)

    Rao, Arjun Harsha

    General Aviation (GA) is a catchall term for all aircraft operations in the US that are not categorized as commercial operations or military flights. GA aircraft account for almost 97% of the US civil aviation fleet. Unfortunately, GA flights have a much higher fatal accident rate than commercial operations. Recent estimates by the Federal Aviation Administration (FAA) showed that the GA fatal accident rate has remained relatively unchanged between 2010 and 2015, with 1566 fatal accidents accounting for 2650 fatalities. Several research efforts have been directed towards betters understanding the causes of GA accidents. Many of these efforts use National Transportation Safety Board (NTSB) accident reports and data. Unfortunately, while these studies easily identify the top types of accidents (e.g., inflight loss of control (LOC)), they usually cannot identify why these accidents are happening. Most NTSB narrative reports for GA accidents are very short (many are only one paragraph long), and do not contain much information on the causes (likely because the causes were not fully identified). NTSB investigators also code each accident using an event-based coding system, which should facilitate identification of patterns and trends in causation, given the high number of GA accidents each year. However, this system is susceptible to investigator interpretation and error, meaning that two investigators may code the same accident differently, or omit applicable codes. To facilitate a potentially better understanding of GA accident causation, this research develops a state-based approach to check for logical gaps or omissions in NTSB accident records, and potentially fills-in the omissions. The state-based approach offers more flexibility as it moves away from the conventional event-based representation of accidents, which classifies events in accidents into several categories such as causes, contributing factors, findings, occurrences, and phase of flight. The method

  14. Bulgarian emergency response system in case of nuclear accident: description, performance and verification

    International Nuclear Information System (INIS)

    Syrakov, D.; Prodanova, M.; Slavov, K.

    2004-01-01

    A PC-oriented Emergency Response System (ERS) is developed and works in National Institute of Meteorology and Hydrology with Bulgarian Academy of Science. The creation and the development of ERS was highly stimulated by the CEC/IAEA/WMO project ETEX (European Tracer EXperiment). ERS comprises of two main parts - operational and accidental ones, realized for both regions 'Europe' and 'Northern Hemisphere'. The operational part runs automatically. It consists of the following modules: selection of proper meteorological data (analyses and forecast) received via the Global Telecommunication System (GTS) of WMO; preparation of input meteorological files used by both trajectory and dispersion models (so called operational data base); completion of the respective meteorological archives, trajectory calculations for selected NPP in Europe and Northern Hemisphere; visualization of the results and putting the pictures in a specialized Web-site. The operational part runs every 12 hours, after new meteorological information is received. The accidental part is activated manually when a real radioactive releases in occurred or during emergency exercises. Two Bulgarian dispersion models - LED and EMAP are a core of the accidental part, LED (Lagrangean-Eulerian Diffusion) being a typical puff-model, wile EMAP (Eulerian Model for Air Pollution) is a 3-D dispersion model. The source input is specified by the user - Bulgarian emergency authorities, and the visualized output (pollution distribution maps) is sent back via fax and FTP. In the paper, the ERS overall structure and its modules are described and an ERS application in emergency management is shown. (authors)

  15. Development of severe accident management advisory and training simulator (SAMAT)

    International Nuclear Information System (INIS)

    Jeong, K.-S.; Kim, K.-R.; Jung, W.-D.; Ha, J.-J.

    2002-01-01

    The most operator support systems including the training simulator have been developed to assist the operator and they cover from normal operation to emergency operation. For the severe accident, the overall architecture for severe accident management is being developed in some developed countries according to the development of severe accident management guidelines which are the skeleton of severe accident management architecture. In Korea, the severe accident management guideline for KSNP was recently developed and it is expected to be a central axis of logical flow for severe accident management. There are a lot of uncertainties in the severe accident phenomena and scenarios and one of the major issues for developing a operator support system for a severe accident is the reduction of these uncertainties. In this paper, the severe accident management advisory system with training simulator, SAMAT, is developed as all available information for a severe accident are re-organized and provided to the management staff in order to reduce the uncertainties. The developed system includes the graphical display for plant and equipment status, the previous research results by knowledge-base technique, and the expected plant behavior using the severe accident training simulator. The plant model used in this paper is oriented to severe accident phenomena and thus can simulate the plant behavior for a severe accident. Therefore, the developed system may make a central role of the information source for decision-making for a severe accident management, and will be used as the training simulator for severe accident management

  16. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The Worker's and Employee's Board (Kammer fuer Arbeiter und Angestellte) organized in February 1987 a meeting on Chernobyl, especially with the topics: consequences of the incident and radiation burden: how the public was informed; how the authorities responded. The present volume is a partial proceedings of several contributions. There is the main paper by E. Heinrich 'The Chernobyl reactor accident. Limiting Values and Measuring System in Austria' and in addition a critique of the Austrian authorities' activities in the wake of the accident. In an appendix a Common Market Commission proposal for the limiting contamination values in the foodstuffs in emergency case, of June 16 th 1987 is quoted and commented outrangedly - by quoting a contribution 'A teaching piece on how radioactivity is played down' in a West German newspaper. (qui)

  17. IMPACT OF HEATING AND AIR CONDITIONING SYSTEM OPERATION AND LEAKAGE ON VENTILATION AND INTERCOMPARTMENT TRANSPORT: STUDIES IN UNOCCUPIED AND OCCUPIED TENNESSEE VALLEY HOMES

    Science.gov (United States)

    Forced-air heating and air conditioning (HAC) systems caused an average and maximum increase in air infiltration rates of 1.8- and 4.3-fold, respectively, during brief whole-house studies of tracer gas decay In 39 occupied houses. An average Increase in air infiltration rate of 0...

  18. Interfacing systems LOCA (loss-of-coolant accidents): Pressurized water reactors

    International Nuclear Information System (INIS)

    Bozoki, G.; Kohut, P.; Fitzpatrick, R.

    1989-02-01

    This report summarizes a study performed by Brookhaven National Laboratory for the Office of Nuclear Regulatory Research, Reactor and Plant Safety Issues Branch, Division of Reactor and Plant Systems, US Nuclear Regulatory Commission. This study was requested by the NRC in order to provide a technical basis for the resolution of Generic Issue 105 ''Interfacing LOCA at LWRs.'' This report deals with pressurized water reactors (PWRs). A parallel report was also accomplished for boiling water reactors. This study focuses on three representative PWRs and extrapolates the plant-specific findings for their generic applicability. In addition, a generic analysis was performed to investigate the cost-benefit aspects of imposing a testing program that would require some minimum level of leak testing of the pressure isolation valves on plants that presently have no such requirements. 28 refs., 31 figs., 64 tabs

  19. Sipa, a real time system for post-accident training and studies

    International Nuclear Information System (INIS)

    Peltier, J.; Poizat, F.

    1990-06-01

    The SIPA simulator, now under development, is designed to study in real time PWR behaviour under normal and accidental conditions. The commissioning of the version for EDF, called SIPA 1, and of the CEA version called SIPA 2 is planned in 1991. Its objectives are Shift Safety Advisors training, studies and safety analysis. Its software workshop will allow flexibility and portability. Most of the models are developed using code generators. The primary circuit is described by CATHARE-SIMU, a speeded-up version of the French advanced code CATHARE. It will be completed by about 35 connected systems developed by THOMSON-CSF and SEMA-GROUP. The computational power will be supplied by a CRAY processor that will be linked to a training network and an engineering network constituted of some independent workstations

  20. System for mitigating consequences of loss of coolant accident at nuclear power station

    International Nuclear Information System (INIS)

    Bukrinsky, A.M.; Rzheznikov, J.V.; Shvyryaev, J.V.; Zlatin, D.A.; Kuznetsov, J.A.; Babenko, E.A.; Tatarnikov, V.P.; Lapshin, A.L.; Sanovich, V.I.

    1981-01-01

    The system according to the invention comprises a first room which accommodates a reactor plant and an active-type sprinkler means. As pressure rises in the first room due to a release of steam from the lost coolant, most of the air contained in this first room is driven out through holes provided in walls of the first room in immediate proximity to a floor of the first room, wherefrom it proceeds to a second room through channels and a basin-type condenser accommodated in the second room. The length of the channels is selected so as to form a water seal in these channels to prevent the back-flow of air from the second room to the first room and thus produce rarefaction in the first room. (author)

  1. Methodology for decision making in environmental restoration after nuclear accidents: temas system (version 2.1)

    International Nuclear Information System (INIS)

    Montero, M.; Moraleda, M.; Claver, F.; Vazquez, C.; Gutierrez, J.

    2001-01-01

    TEMAS is an user-friendly decision aiding computerised system to help in the selection of the best local strategy of restoration when a post-accidental environmental contamination with long lived radionuclides (''137 Cs and ''90 Sr) must be faced TEMAS provides answer for complex scenarios on whichever place of the European Community territory ( urban agricultural and forest) with different specific levels of contamination, uses and dimensions. The initial version was the result of the TEMAS project (Techniques and Management Strategies for Environmental Restoration) supported by the EU during the 4th Framework Program. Some Aspects of the methodology are at present being improved. This document applies to the computerised version 2.1 (VAZ01). (Author)

  2. Software concepts for the build-up of complex systems - selection and realization taking as example a program system for calculation of hypothetical core meltdown accidents

    International Nuclear Information System (INIS)

    Scheuermann, W.

    1994-10-01

    Development and application of simulation systems for the analysis of complex processes require on the one hand and detailed engineering knowledge of the plant and the processes to be simulated and on the other hand a detailled knowledge about software engineering, numerics and data structures. The cooperation of specialists of both areas will become easier if it is possible to reduce the complexicity of the problems to be solved in a way that the analyses will not be disturbed and the communication between different disciplines will not become unnecessarily complicated. One solution to reduce the complexity is to consider computer science as an engineering discipline which provides mainly abstract elements and to allow engineers to build application systems based on these abstract elements. The principle of abstraction leads through the processes of modularisation and the solution of the interface problem to an almost problem independent system architecture where the elements of the system (modules, model components and models) operate only on those data assigned to them. In addition the development of abstract data types allows the formal description of the relations and interactions between system elements. This work describes how these ideas can be concretized to build complex systems which allow reliable and effective problem solutions. These ideas were applied successfully during the design, realization and application of the code system KESS, which allows the analysis of core melt down accidents in pressurized water reactors. (orig.) [de

  3. 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

  4. Preventive testing and leakage detection in pipe-lines of steam condensers and generators of a PWR type reactor

    International Nuclear Information System (INIS)

    Canalini, A.; Carvalho, N.C. de

    1985-01-01

    The non-destructive methods: Spum, Helium and Hydrostatic used in leakage detection in condenser pipelines for PWR type reactors are presented. The time, costs, sensitivity, resources necessary and personnel development factors are considered to choose adequated method, in function of nuclear power plant conditions. The leakage tests are applied in pressurized systems or vacuum. Eddy Current testing is used in condensers and steam generators aiming to avoid leakage in these equipments. The spume testing for leakage detection in condenser pipelines - which operation - and hydrostatic testing for leakage detection through reaming with shutdown - were most efficients. The Helium testing applied in pressurized systems or submitted to vacuum systems presented satisfactory results. The Eddy Current testing in condenser and steam generator pipelines reached desired objective, reducing leakage in the first and preserving the integrity in the second. (M.C.K.) [pt

  5. Status of the organs of the digestive system in employees of the Chernobyl nuclear power plant engaged in recovery work after the accident

    International Nuclear Information System (INIS)

    Yaimenko, L.; Moroz, G.Z.; Sobchuk, Y.A.

    1995-01-01

    This work deals with the status of the digestive system in employees of the Chernobyl nuclear power plant engaged in recovery work after the accident. Morphological and functional changes suffered by the digestive organs on exposure to ionizing radiation in doses leading to the development of acute radiation sickness are described. The effect of small doses ionizing radiation on the human body is indicated too. (O.L.). 15 refs., 1 tab

  6. Loss of Coolant Accident (LOCA) / Emergency Core Coolant System (ECCS Evaluation of Risk-Informed Margins Management Strategies for a Representative Pressurized Water Reactor (PWR)

    Energy Technology Data Exchange (ETDEWEB)

    Szilard, Ronaldo Henriques [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    A Risk Informed Safety Margin Characterization (RISMC) toolkit and methodology are proposed for investigating nuclear power plant core, fuels design and safety analysis, including postulated Loss-of-Coolant Accident (LOCA) analysis. This toolkit, under an integrated evaluation model framework, is name LOCA toolkit for the US (LOTUS). This demonstration includes coupled analysis of core design, fuel design, thermal hydraulics and systems analysis, using advanced risk analysis tools and methods to investigate a wide range of results.

  7. Apparatus for detecting leakage of liquid sodium

    Science.gov (United States)

    Himeno, Yoshiaki

    1978-01-01

    An apparatus for detecting the leakage of liquid sodium includes a cable-like sensor adapted to be secured to a wall of piping or other equipment having sodium on the opposite side of the wall, and the sensor includes a core wire electrically connected to the wall through a leak current detector and a power source. An accidental leakage of the liquid sodium causes the corrosion of a metallic layer and an insulative layer of the sensor by products resulted from a reaction of sodium with water or oxygen in the atmospheric air so as to decrease the resistance between the core wire and the wall. Thus, the leakage is detected as an increase in the leaking electrical current. The apparatus is especially adapted for use in detecting the leakage of liquid sodium from sodium-conveying pipes or equipment in a fast breeder reactor.

  8. 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.)

  9. 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

  10. 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

  11. Using Geographic Information Systems (GIS) to Characterize Pediatric Pedestrian Motor Vehicle Accidents in the State of Delaware.

    Science.gov (United States)

    Talati, Ravi; Stegmuller, Angela; Niiler, Tim; Xiang, Huiyun; Atanda, Alfred

    2016-07-01

    Pediatric pedestrian motor vehicle-associated of injuries correlated with a particular census tract's trauma is a significant public health concern for children. demographic composition. GIS mapping software was used We aimed to use geographic information systems (GIS) to examine the relationship between motor vehicle pedestrian injuries in children and the demographics of the region in which they occurred for the state of Delaware. This is a retrospective analysis of collected data from the Delaware State Trauma Registry form January 1, 2002, to December 31, 2012. The records of all patients younger than 18 years who went to one of the state's six trauma centers during the study were reviewed. For each injury event, patient demographic information was recorded, and latitude/longitude coordinates of the injury site were determined. Median income, minority population, education level, and percentage of males and children in the census tract were obtained from state census data. Analysis of variance was used to characterize how the frequency of injuries correlated with a particular census tract's demographic composition. GIS mapping software was used to identify specific "hot spots" throughout the state where the examine the relationship between motor vehicle pedestrian frequency of traffic crash events was the highest. Urban and poorer areas had tile highest number of injury events, with Wilmington having the highest frequency Methods: This is a retrospective analysis of collected data of injuries per capita. Census tracts with low median income, from the Delaware State Trauma Registry from January 1, lack of high school degree, and increased percentage of 2002, to December 31, 2012. The records of all patients African Americans and females had significantly higher injury younger than 18 years who went to one of the state's six counts compared with other census tracts. In the state of Delaware, children in urban and poor areas are disproportionately affected by

  12. Leakage and sweet spots in triple-quantum-dot spin qubits: A molecular-orbital study

    Science.gov (United States)

    Zhang, Chengxian; Yang, Xu-Chen; Wang, Xin

    2018-04-01

    A triple-quantum-dot system can be operated as either an exchange-only qubit or a resonant-exchange qubit. While it is generally believed that the decisive advantage of the resonant-exchange qubit is the suppression of charge noise because it is operated at a sweet spot, we show that the leakage is also an important factor. Through molecular-orbital-theoretic calculations, we show that when the system is operated in the exchange-only scheme, the leakage to states with double electron occupancy in quantum dots is severe when rotations around the axis 120∘ from z ̂ is performed. While this leakage can be reduced by either shrinking the dots or separating them further, the exchange interactions are also suppressed at the same time, making the gate operations unfavorably slow. When the system is operated as a resonant-exchange qubit, the leakage is three to five orders of magnitude smaller. We have also calculated the optimal detuning point which minimizes the leakage for the resonant-exchange qubit, and have found that although it does not coincide with the double sweet spot for the charge noise, they are rather close. Our results suggest that the resonant-exchange qubit has another advantage, that leakage can be greatly suppressed compared to the exchange-only qubit, and operating at the double sweet spot point should be optimal both for reducing charge noise and suppressing leakage.

  13. Explanatory memorandum on European Community Document 6323/87: proposal for a Council decision on a Community system of rapid exchange of information in cases of abnormal levels of radioactivity or of a nuclear accident

    International Nuclear Information System (INIS)

    1987-01-01

    The Council of the European Commnity proposes a system of rapid exchange of information in cases of abnormal radioactivity or a nuclear accident. In addition to the existing procedures of early notification drawn up by the International Atomic Energy Authority this proposes a further notification system between member states of the European Community. Under this there would be notification, not only of accidents with possible transboundary effects, but of any accident for which emergency measures are taken to protect the public. However, the United Kingdom would prefer the trigger of these procedures to be abnormally high radiation levels rather than the introduction of emergency measures. (U.K.)

  14. [Oxygen therapy in diving accidents].

    Science.gov (United States)

    Piepho, T; Ehrmann, U; Werner, C; Muth, C M

    2007-01-01

    Diving accidents represent a departure from the routine practice of emergency physicians. The incidence of non-fatal diving accidents is reported as 1-2 per 10,000 dives. Apart from adequate intravenous hydration, oxygen is the only medication with a proven effect in the treatment of diving accidents. After a typical diving accident, administration of oxygen at an inspired concentration (F(I)O(2) 1.0) as high as possible is recommended. Many divers bring along their own oxygen administration systems to the diving sites and these are often better suited for the treatment of diving accidents than the oxygen systems of many emergency responders. Pressure regulators supplying low constant flow oxygen, nasal prongs and inhalation masks are inappropriate. When using artificial ventilation bags with face masks, an oxygen flow of at least 15 l/min should be used. Demand regulators are simple to use and able to deliver a F(I)O2 of 1.0. Their ease of use has earned them high marks in the emergency management of diving accidents and their similarity to standard diving equipment has also aided relatively widespread acceptance. Circulation breathing systems are more technologically complex oxygen delivery systems which permit CO2 absorption and re-breathing at low oxygen flow. In contrast to the demand modules, the likelihood of mistakes during their usage is higher. In diving accidents, the administration of normobaric oxygen, already begun in the field, is the most important therapy and should not be interrupted. Presented with an inadequate supplemental oxygen supply, the inspired oxygen concentration should not be decreased, rather the duration of the oxygen administration should be reduced. Hyperbaric oxygen therapy should be the mainstay of further treatment.

  15. Thyroid system morphofunctional state in children from Chernigiv Region after thyroid gland irradiation after the accident at Chernobyl Atomic Power Station

    International Nuclear Information System (INIS)

    Yakovljev, O.O.; Bjelyikova, N.M.; Bobil'ova, O.O.; Bliznyuk, Z.V.; Lukoms'ka, Yi.G.; Antipkyin, Yu.G.

    1994-01-01

    510 children from Chernigiv Region aged 6 - 14 were examined. The program of the examination included investigation of the thyroid system morphofunctional state when compared with the doses of thyroid gland irradiation with iodine-131 during the accident at Chernobyl Atomic Power Station (CAPS). Relative hyperthyroxinemia and hyperthyroglobulinemia which did not depend on the dose have been revealed. The results of the investigation showed that 5 - 6 years after the accident at CAPS, deviations from the norm in the hormones level without marked clinical features of the disease were observed in the majority of cases. Due to this fact the children living in the contaminated with radionuclides areas should be included to the risk-group of appearance of radiation induced morphological and functional changes of the thyroid gland

  16. INSTALLATION OF A POST-ACCIDENT CONFINEMENT HIGH-LEVEL RADIATION MONITORING SYSTEM IN THE KOLA NUCLEAR POWER STATION (UNIT 2) IN RUSSIA

    Energy Technology Data Exchange (ETDEWEB)

    GREENE,G.A.; GUPPY,J.G.

    1998-09-01

    This is the final report on the INSP project entitled, ``Post-Accident Confinement High-Level Radiation Monitoring System'' conducted by BNL under the authorization of Project Work Plan WBS 1.2.2.6 (Attachment 1). This project was initiated in February 1993 to assist the Russians in reducing risks associated with the continued operation of older Soviet-designed nuclear power plants, specifically the Kola VVER-440/230 Unit 2, through improved accident detection capability, specifically by the installation of a dual train high-level radiation detection system in the confinement of Unit 2 of the Kola NPP. The major technical objective of this project was to provide, install and make operational the necessary hardware inside the confinement of the Kola NPP Unit 2 to provide early and reliable warning of the release of radionuclides from the reactor into the confinement air space as an indication of the occurrence of a severe accident at the plant. In addition, it was intended to provide hands-on experience and training to the Russian plant workers in the installation, operation, calibration and maintenance of the equipment in order that they may use the equipment without continued US assistance as an effective measure to improve reactor safety at the plant.

  17. INSTALLATION OF A POST-ACCIDENT CONFINEMENT HIGH-LEVEL RADIATION MONITORING SYSTEM IN THE KOLA NUCLEAR POWER STATION (UNIT 2) IN RUSSIA

    International Nuclear Information System (INIS)

    GREENE, G.A.; GUPPY, J.G.

    1998-01-01

    This is the final report on the INSP project entitled, ''Post-Accident Confinement High-Level Radiation Monitoring System'' conducted by BNL under the authorization of Project Work Plan WBS 1.2.2.6 (Attachment 1). This project was initiated in February 1993 to assist the Russians in reducing risks associated with the continued operation of older Soviet-designed nuclear power plants, specifically the Kola VVER-440/230 Unit 2, through improved accident detection capability, specifically by the installation of a dual train high-level radiation detection system in the confinement of Unit 2 of the Kola NPP. The major technical objective of this project was to provide, install and make operational the necessary hardware inside the confinement of the Kola NPP Unit 2 to provide early and reliable warning of the release of radionuclides from the reactor into the confinement air space as an indication of the occurrence of a severe accident at the plant. In addition, it was intended to provide hands-on experience and training to the Russian plant workers in the installation, operation, calibration and maintenance of the equipment in order that they may use the equipment without continued US assistance as an effective measure to improve reactor safety at the plant

  18. The hypothalomo-pituitary-adrenal system in liquidators of the Chernobyl accident consequences: summing up the seven-year follow-up

    International Nuclear Information System (INIS)

    Mitryaeva, N.A.

    1996-01-01

    The function of the hypothalamo-pituitary-adrenal system was studied over time (1986-1993) in 500 liquidators of the Chernobyl accident consequences with external exposure dose of 250 mSv. The concentrations of hydrocortisone, ACTH, and β-endorphine in the peripheral blood were radioimmunoassayed at rest and during functional loading. Glucocorticoids were measured in the urine by thin-layer chromatography. The number of glucocorticoid receptors in peripheral blood lymphocytes was assessed by the radioreceptor method. Stable hypercorticalism in the presence of reduced β-endorphine and increased ACTH levels was observed in the majority of examinees during the first years after the accident. Six years after the accident the above parameters were normal at rest, although during functional loading disorders in the reserve potential of the hypothalamo-pituitary-adrenal system were observed, which deteriorated its adaptation to changes int he environment. It is advisable to single out high risk groups of subjects with disadaptation disorders for regular check-ups among the liquidators. 10 refs.; 3 figs.; 4 tabs

  19. Radiological aspects of nuclear accident scenarios. Volume 1 real-time emergency response systems post-Chernobyl action

    International Nuclear Information System (INIS)

    Sinnaeve, J.

    1991-01-01

    In the event of a nuclear accident, there is a need for a rapid assessment of the resulting levels of environmental contamination in order to facilitate decisions on possible countermeasures. Volume 1 of this report covers the development of numerical models, in the form of software packages, to simulate atmospheric transport and deposition over various distances, and techniques for estimation of the resulting doses

  20. Safety during sea transport of radioactive materials. Probabilistic safety analysis of package fro sea surface fire accident

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Obara, Isonori; Akutsu, Yukio; Aritomi, Masanori

    2000-01-01

    The ships carrying irradiated nuclear fuel, plutonium and high level radioactive wastes(INF materials) are designed to keep integrity of packaging based on the various safety and fireproof measures, even if the ship encounters a maritime fire accident. However, granted that the frequency is very low, realistic severe accidents should be evaluated. In this paper, probabilistic safety assessment method is applied to evaluate safety margin for severe sea fire accidents using event tree analysis. Based on our separate studies, the severest scenario was estimated as follows; an INF transport ship collides with oil tanker and induces a sea surface fire. Probability data such as ship's collision, oil leakage, ignition, escape from fire region, operations of cask cooling system and water flooding systems were also introduced from above mentioned studies. The results indicate that the probability of which packages cannot keep their integrity during the sea surface fire accident is very low and sea transport of INF materials is carried out very safely. (author)

  1. 48 CFR 836.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident prevention. 836.513 Section 836.513 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 836.513 Accident prevention. The contracting officer must inser...

  2. 48 CFR 36.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Accident prevention. 36.513 Section 36.513 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.513 Accident prevention. (a) The contracting officer shall...

  3. 48 CFR 1836.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Accident prevention. 1836.513 Section 1836.513 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 1836.513 Accident prevention. The contracting...

  4. A preview of the efficiency of systemic family therapy in treatment of children with posttraumatic stress disorder developed after car accident

    Directory of Open Access Journals (Sweden)

    Stanković Miodrag

    2013-01-01

    Full Text Available Background/Aim. Traumatic stress refers to physical and emotional reactions caused by events which represent a life threat or a disturbance of physical and phychological integrity of a child, as well as their parents or gaerdians. Car accidents are the main cause of posttraumatic stress disorder (PTSD in children. The aim of this study was to preview clinical efficiency of systemic family therapy (SFT as therapy intervention in treatment of children with posttraumatic stress disorder (PTSD traumatized in car accident under identical circumstances of exposure. We pointed out the importance of specific family factors (family cohesion and adaptability, emotional reaction of the parents on PTSD clinical outcome. Methods. The sample of this clinical observational study included 7-sixth grade pupiles - 5 boys and 2 girls, aged 13. All of the pupils were involved in car accident with one death. Two groups were formed - one group included three children who were involved in 8 SFT sessions together with their families. The second group included 4 children who received an antidepressant sertraline in the period of three months. Results. Two months after the car accident, before the beginning of the therapy, all of the children were the members of rigidly enmeshed family systems, considering the high average cohesion scores and the low average adaptability scores on the FACES III. Three months after the received therapy, having evaluated the results of the therapeutic approaches, we established that the adaptability scores of the families included in the SFT were higher than the scores of the families of the children who received pharmacotherapy with one boy still meeting the criteria for PTSD. Conclusion. Systemic family therapy was efficient in the treatment of children with PTSD, traumatized in car accident. Therapy efficiency was higher when both parents and children were included in SFT than in the case when they were not included in the family

  5. Impact of leakage delay on bifurcation in high-order fractional BAM neural networks.

    Science.gov (United States)

    Huang, Chengdai; Cao, Jinde

    2018-02-01

    The effects of leakage delay on the dynamics of neural networks with integer-order have lately been received considerable attention. It has been confirmed that fractional neural networks more appropriately uncover the dynamical properties of neural networks, but the results of fractional neural networks with leakage delay are relatively few. This paper primarily concentrates on the issue of bifurcation for high-order fractional bidirectional associative memory(BAM) neural networks involving leakage delay. The first attempt is made to tackle the stability and bifurcation of high-order fractional BAM neural networks with time delay in leakage terms in this paper. The conditions for the appearance of bifurcation for the proposed systems with leakage delay are firstly established by adopting time delay as a bifurcation parameter. Then, the bifurcation criteria of such system without leakage delay are successfully acquired. Comparative analysis wondrously detects that the stability performance of the proposed high-order fractional neural networks is critically weakened by leakage delay, they cannot be overlooked. Numerical examples are ultimately exhibited to attest the efficiency of the theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Four years after the JCO criticality accident

    International Nuclear Information System (INIS)

    Sumita, Kenji

    2003-01-01

    It has been about four years since the first criticality accident in Japan. The JCO accident site was not so far from this auditorium. I have been asked to give a short review of important results from the various technical investigations on the accident that have been performed during the past four years. I will also give a short introduction to the changes that have been made in the nuclear safety regulation systems of the Japanese Government. (author)

  7. The second EURADOS intercomparison of national network systems used to provide early warning of a nuclear accident

    International Nuclear Information System (INIS)

    Saez-Vergara, J. C.; Thompson, I. M. G.; Gurriaran, R.; Dombrowski, H.; Funck, E.; Neumaier, S.

    2007-01-01

    In 1999 and 2002, the EURADOS Working Group on Environmental Monitoring organised two European intercomparison exercises of national network systems used to provide early warning in case of a nuclear accident. In total, 12 European countries, represented by more than 40 scientists, participated in these two intercomparisons with more than 35 different dose rate detectors. In addition, an in situ gamma spectrometry intercomparison was performed by a group of European scientists during the 2002 exercise. Results of these spectrometry measurements will be reported elsewhere. This report summarises the results of the second intercomparison, performed in 2002, at the environmental dosimetry facilities of the Physikalisch-Technische Bundesanstalt (PTB) in Germany. The unique combination of the ultra-low background Underground Laboratory (UDO) and two free-field sites (a floating platform on a lake showing an almost pure cosmic radiation field and a free-field gamma ray irradiation facility) provide the particular opportunity to precisely quantify the inherent background of the detectors and to calibrate them almost free of any background and traceable to PTB's primary standards. In addition, the intercomparison comprised investigations on the energy and dose rate dependence of the detectors' response to gamma radiation as well as on the response to cosmic radiation. Finally, the sensitivity of the detector systems to small dose rate variations, similar to that caused by a passing overhead radioactive plume, was studied under realistic free-field conditions. Following the Council Directive 96/29/EURATOM, the participants of the 2002 intercomparison were asked to report their results in terms of the operational quantity ambient dose equivalent, H*(10). Although the verification of the individual calibrations showed smaller discrepancies than those in the 1999 intercomparison, in a few cases, these discrepancies would be still unacceptably high in the case of a real

  8. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakag...

  9. Requirements for a multifunctional decision support system within accident and emergency management organizations exemplified by the Joint Nordic Programme: NKA/INF

    International Nuclear Information System (INIS)

    Berg, O.

    1988-01-01

    The increasing potential for severe accidents as industries develop larger centralized production units has led to the formation of large organizations prepared for accident and emergency management. One important task within these organizations will be information management. Insufficient access to information and expert knowledge, combined with a stressful working situation, may lead to incorrect or poor decisions during an emergency. The aim of the joint Nordic five year (1985-89) research programme NKA/INF is to improve the efficiency of accident and emergency management. This will be achieved by developing and evaluating a prototype decision support system for various organizations in their information retrieval and decision making tasks. Functions for both on-site and off-site organizations during an emergency situation are specified, including identification of important communication paths. The system structure must be flexible in order easily to modify or add new features. This is emphasized by choosing an object oriented programming approach and representing data and knowledge in a structure facilitating incremental system development. A variety of functions for data presentation, message passing, diagnosis and procedures in emergency situations are described. Since this type of system will not be in daily use, the man-machine interface and dialogue features should be made as self-explanatory and informative as possible for the various users. Thus the various screen layouts will be designed to match the different user categories with respect to data types and level of detail, as shown in the examples. The system will be designed to assist the user in parallel tasks. To achieve this, several windows will be visible at the same time. It is expected that this will yield a better overview as well. Experiments with the prototype system on different emergency scenarios are planned for the end of 1988. (author). Poster presentation. 5 refs, 2 figs

  10. The Diagnosis of Internal Leakage of Control Valve Based on the Grey Correlation Analysis Method

    Directory of Open Access Journals (Sweden)

    Zheng DING

    2014-07-01

    Full Text Available The valve plays an important part in the industrial automation system. Whether it operates normally or not relates with the quality of the products directly while its faults are relatively common because of bad working conditions. And the internal leakage is one of the common faults. Consequently, this paper sets up the experimental platform to make the valve in different working condition and collect relevant data online. Then, diagnose the internal leakage of the valve by using the grey correlation analysis method. The results show that this method can not only diagnose the internal leakage of valve accurately, but also distinguish fault degree quantitatively.

  11. Development of a computer code system for selecting off-site protective action in radiological accidents based on the multiobjective optimization method

    International Nuclear Information System (INIS)

    Ishigami, Tsutomu; Oyama, Kazuo

    1989-09-01

    This report presents a new method to support selection of off-site protective action in nuclear reactor accidents, and provides a user's manual of a computer code system, PRASMA, developed using the method. The PRASMA code system gives several candidates of protective action zones of evacuation, sheltering and no action based on the multiobjective optimization method, which requires objective functions and decision variables. We have assigned population risks of fatality, injury and cost as the objective functions, and distance from a nuclear power plant characterizing the above three protective action zones as the decision variables. (author)

  12. Vent clearing during a simulated loss-of-coolant accident in Mark I boiling-water-reactor pressure-suppression system

    International Nuclear Information System (INIS)

    Pitts, J.H.; McCauley, E.W.

    1978-01-01

    The response of the pressure-suspension containment system of Mark I boiling-water reactors to a loss-of-coolant accident (LOCA) is being studied. This response is a design basis for light-water nuclear reactors. Part of the study is being carried out on a 1 / 5 -scale experimental facility that models the pressure-suppression containment system of the Peach Bottom 2 nuclear power plant. The test series reported here focused on the initial or air-clearing phase of a hypothetical LOCA. Measured forces, measured pressures, and the hydrodynamic phenomena (observed with high-speed cameras) show a logical interrelationship

  13. Distributed public key schemes secure against continual leakage

    DEFF Research Database (Denmark)

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... the value of the respective function on the internal state of the respective device (namely, on its secret share, internal randomness, and results of intermediate computations). We present distributed public key encryption (DPKE) and distributed identity based encryption (DIBE) schemes that are secure......-secure against continual memory leakage. Our DPKE scheme also implies a secure storage system on leaky devices, where a value s can be secretely stored on devices that continually leak information about their internal state to an external attacker. The devices go through a periodic refresh protocol...

  14. Air Leakage and Air Transfer Between Garage and Living Space

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Westford, MA (United States)

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed.

  15. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    : This study is a systematic review using the databases MEDLINE and Rex. MEDLINE was searched up to October 2010 to identify studies on experimental animal models of clinical colon anastomotic leakage. From the Rex database, textbooks on surgical aspects as well as gastrointestinal physiology and anatomy...... interventions are needed to create clinical leakage in these animals. The knowledge from this study formed the basis for selecting the animal species most suited for the models in the next studies. STUDY 2: In this experimental study, technically insufficient colonic anastomoses were performed in 110 C57BL/6...... instead of clinical leakage. However, anastomotic breaking strength was reduced in the ischemic anastomoses. STUDY 4: In this systematic review MEDLINE, Embase and Cinahl were searched up to September 2011 to identify studies evaluating external coating of colonic anastomoses. Most studies were...

  16. Accident prevention in radiotherapy.

    Science.gov (United States)

    Holmberg, O

    2007-04-01

    In order to prevent accidents in radiotherapy, it is important to learn from accidents that have occurred previously. Lessons learned from a number of accidents are summarised and underlying patterns are looked for in this paper. Accidents can be prevented by applying several safety layers of preventive actions. Categories of these preventive actions are discussed together with specific actions belonging to each category of safety layer.

  17. Accident prevention in radiotherapy

    OpenAIRE

    Holmberg, O

    2007-01-01

    In order to prevent accidents in radiotherapy, it is important to learn from accidents that have occurred previously. Lessons learned from a number of accidents are summarised and underlying patterns are looked for in this paper. Accidents can be prevented by applying several safety layers of preventive actions. Categories of these preventive actions are discussed together with specific actions belonging to each category of safety layer.

  18. Studies of water leakage in dams. Course

    International Nuclear Information System (INIS)

    Cordero-Calderon, C.F.

    1995-01-01

    With this training about the study of Water Leakage in Dams and Damming, the institutional worker will have the necessary criteria in this topic, and also an opportunity to analyze the impact of this engineering work at national level. This course permits to transmit part of the knowlege acquired by the Arcal XVIII RLA/8/018, Application of Tracer Techniques for Leakage in Dams and Damming Project, where ICE participates in agreement with Atomic Energy Commission of Costa Rica, sponsored by the International Organization of Atomic Energy. (author). 14 charts, 36 figs, 2 maps, 6 tabs

  19. Inward Leakage in Tight-Fitting PAPRs

    Directory of Open Access Journals (Sweden)

    Frank C. Koh

    2011-01-01

    Full Text Available A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs, the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form.

  20. The Leakage determination on corrosion fretting machine

    International Nuclear Information System (INIS)

    Sriyono; Satmoko, Ari; Hafid, Abdul; Febrianto; Prasetio, Joko; Abtokhi; Sumarno, Edy; Handoyo, Ismu; Hidayati, Nur Rahmah; Histori

    1998-01-01

    Fretting machine is an experimental loop to learn fretting corrosion phenomena wich is caused by loading and vibration. On the steam generator, one of the corrosion process that's occurred, it can be caused by vibration between tubes and bending material. Because of high flow rate inside the tube, the high frequency vibration will appeared so it can make the corrosion on bending material more faster. This process can be simulate by fretting machine. This machine has already damage because of leakage. So it will be repaired by dismantling, radiography testing and redrawing. from the result of radiography, the leakage is caused by cracking on bellows seals of the dynamic main support