Study on mitigation of in-vessel release of fission products in severe accidents of PWR

International Nuclear Information System (INIS)

Huang, G.F.; Tong, L.L.; Li, J.X.; Cao, X.W.

2010-01-01

Research highlights: → In-vessel release of fission products in severe accidents for 600 MW PWR is analyzed. → Mitigation effect of primary feed-and-bleed on in-vessel release is investigated. → Mitigation effect of secondary feed-and-bleed on in-vessel release is studied. → Mitigation effect of ex-vessel cooling on in-vessel release is evaluated. - Abstract: During the severe accidents in a nuclear power plant, large amounts of fission products release with accident progression, including in-vessel and ex-vessel release. Mitigation of fission products release is demanded for alleviating radiological consequence in severe accidents. Mitigation countermeasures to in-vessel release are studied for Chinese 600 MW pressurized water reactor (PWR), including feed-and-bleed in primary circuit, feed-and-bleed in secondary circuit and ex-vessel cooling. SBO, LOFW, SBLOCA and LBLOCA are selected as typical severe accident sequences. Based on the evaluation of in-vessel release with different startup time of countermeasure, and the coupling relationship between thermohydraulics and in-vessel release of fission products, some results are achieved. Feed-and-bleed in primary circuit is an effective countermeasure to mitigate in-vessel release of fission products, and earlier startup time of countermeasure is more feasible. Feed-and-bleed in secondary circuit is also an effective countermeasure to mitigate in-vessel release for most severe accident sequences that can cease core melt progression, e.g. SBO, LOFW and SBLOCA. Ex-vessel cooling has no mitigation effect on in-vessel release owing to inevitable core melt and relocation.

Strategies for operation of containment related ESFs in managing activity release to the environment during accident conditions

International Nuclear Information System (INIS)

Bhawal, R.N.; Bajaj, S.S.

1998-01-01

In Indian PHWR design, a double containment concept with passive vapour suppression pool (to limit peak pressure) system has been adopted. In addition to it, various Engineered Safety Features (ESFs) have been incorporated to limit the release of radioactivity to the environment. They are: Reactor building emergency coolers for cooling which results in fast reduction of overpressure; Primary Containment Filtration and Pump Back System (PCFPBS) for reduction in iodine concentration inside RB atmosphere during post LOCA period; and, Primary Containment Controlled Discharge System (PCCDS) for the rapid reduction of over-pressure tail. Due to operation of secondary containment purge system, which maintain negative pressure in the annulus, the ground level release is negligibly small. However, if non- availability of negative pressure in secondary containment space is assumed, then operation of PCFPBS and PCCDS system reduces the ground level release significantly. In this situation, depending upon time of operation of the PCFPBS, it can effectively reduce the iodine release, both in stack level and ground level by trapping it in charcoal filters. It is seen that delay time of PCFPBS operation in conjunction with prevailing weather condition can be manipulated to reduce the effect of stack level release of iodine. In this paper the containment related ESFs used in Indian PHWR is discussed in brief and the effectiveness of operator actions and management strategies in actuation of the ESFs in reducing the activity release to environment (during postulated accident conditions) will be brought out. (author)

Transport of large particles released in a nuclear accident

International Nuclear Information System (INIS)

Poellaenen, R.; Toivonen, H.; Lahtinen, J.; Ilander, T.

1995-10-01

Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d a > 20 μm) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.)

Transport of large particles released in a nuclear accident

Energy Technology Data Exchange (ETDEWEB)

Poellaenen, R; Toivonen, H; Lahtinen, J; Ilander, T

1995-10-01

Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d{sub a} > 20 {mu}m) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.).

Determining cutoff distances for assessing risks from transportation accident radiation releases

International Nuclear Information System (INIS)

Sandquist, G.M.; Slaughter, D.M.; Kimura, C.Y.; Brumburgh, G.

1995-01-01

The transportation of radioactive materials throughout the United States and the world is a ubiquitous and sometimes controversial activity. Almost universally, these transportation activities have been performed without major incident, and the safety record for transportation of radioactive material is outstanding compared with the transportation of other hazardous materials. Nevertheless, concerns still exist regarding adequate regulation of radioactive material transportation and accurate assessment of the health risks associated with accidents. These concerns are addressed through certification by the cognizant regulatory authority over the transportation container or the performance of a transportation risk assessment. In a transportation risk assessment, accident situations are examined, frequencies are estimated, and consequences resulting from the accident are analyzed and evaluated for acceptance. A universal question with any transportation risk assessment that examines the radiological consequences from release accidents is, At what distance may the dispersion analysis be terminated? This paper examines cutoff distances and their consequences for assessing health risks from radiological transportation releases

Fission product release profiles from spherical HTR fuel elements at accident temperatures

International Nuclear Information System (INIS)

Schenk, W.; Pitzer, D.; Nabielek, H.

1986-10-01

A total of 22 fuel elements with modern TRISO particles has been tested in the temperature range 1500-2500 0 C. Additionally, release profiles of iodine and other isotopes have been obtained with seven UO 2 samples at 1400-1800 0 C. For heating times up to 100 hours at the maximum temperature, the following results are pertinent to HTR accident conditions: Ag 110 m is the only fission products to be released at 1200-1600 0 C by diffusion through intact SiC, but it is of low significance in accident assessments; cesium, iodine, strontium, and noble gas releases up to 1600 0 C are solely due to various forms of contamination; at 1700-1800 0 C, corrosion induced SiC defects cause the release of Cs, Sr, I/Xe/Kr; above 2000 0 C, thermal decomposition of the silicon carbide layer sets in while pyrocarbons still remain intact. Around 1600 0 C, the accident specific contribution of cesium, strontium, iodine, and noble gases is negligible. (orig./HP) [de

Release and transport of fission product cesium in the TMI-2 accident

International Nuclear Information System (INIS)

Lorenz, R.A.; Collins, J.L.

1986-01-01

Approximately 50% of the fission product cesium was released from the overheated UO 2 fuel in the TMI-2 accident. Steam that boiled away from a water pool in the bottom of the reactor vessel transported the released fission products throughout the reactor coolant system (RCS). Some fission products passed directly through a leaking valve with steam and water into the containment structure, but most deposited on dry surfaces inside of the RCS before being dissolved or resuspended when the RCS was refilled with water. A cesium transport model was developed that extended measured cesium in the RCS back to the first day of the accident. The model revealed that ∼62% of the released 137 Cs deposited on dry surfaces inside of the RCS before being slowly leached and transported out of the RCS in leaked or letdown water. The leach rates from the model agreed reasonably well with those measured in the laboratory. The chemical behavior of cesium in the TMI-2 accident agreed with that observed in fission product release tests at Oak Ridge National Laboratory (ORNL)

Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

Science.gov (United States)

Abrecht, David G; Schwantes, Jon M

2015-03-03

This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores.

Portable Filtered Air Suction System for Released Radioactive Gases Prevention under a Severe Accident of NPPs

International Nuclear Information System (INIS)

Gu, Beom W.; Choi, Su Y.; Rim, Chun T.

2013-01-01

In this paper, the portable filtered air suction system (PoFASS) for released radioactive gases prevention under a severe accident of NPP is proposed. This technology can prevent the release of the radioactive gases to the atmosphere and it can be more economical than FVCS because PoFASS can cover many NPPs with its high mobility. The conceptual design of PoFASS, which has the highest cost effectiveness and robustness to the environment condition such as wind velocity and precipitation, is suggested and the related previous research is introduced in this paper. The portable filtered air suction system (PoFASS) for released radioactive gases prevention can play a key role to mitigate the severe accident of NPP with its high cost effectiveness and robustness to the environment conditions. As further works, the detail design of PoFASS to fabricate a prototype for a demonstration will be proceeded. When released radioactive gases from the broken containment building in the severe accident of nuclear power plants (NPPs) such as the Chernobyl and Fukushima accidents occur, there are no ways to prevent the released radioactive gases spreading in the air. In order to solve this problem, several European NPPs have adopted the filtered vented containment system (FVCS), which can avoid the containment failure through a pressure relief capability to protect the containment building against overpressure. However, the installation cost of FVCS for a NPP is more than $10 million and this system has not been widely welcomed by NPP operating companies due to its high cost

Tellurium release and deposition during the TMI-2 accident

International Nuclear Information System (INIS)

Vinjamuri, K.; Osetek, D.J.; Hobbins, R.R.; Jessup, J.S.

1984-09-01

The estimated behavior of tellurium during and after the accident at the Three Mile Island Unit-2 is presented. The behavior is based on all available measurement data for /sup 129m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te and 130 Te), and best estimate calculations of tellurium release and transport. The predicted release was calculated using current techniques that relate release rate to fuel temperature and holdup of tellurium in zircaloy until significant oxidation occurs. The calculated release fraction was low, approx. 7%, but the total measured release for samples analyzed to date is about 5.8%. Of the measured tellurium about 2.4, 1.8, 0.88, 0.42, 0.17 and 0.086% of core inventory were in the containment sump water, upper plenum assembly surfaces, containment solids in the sump water, makeup and purification demineralizer, containment inside surface, and the reactor primary coolant, respectively. A significant fraction (54%) of the tellurium calculated to be retained on the upper plenum surfaces (4.61% of the core inventory) was deposited during the high pressure injection of coolant at about 200 min after the reactor scram. Comparison of tellurium behavior with in-pile and out-of-pile tests strongly suggests that zircaloy holds tellurium until significant cladding oxidation occurs

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

International Nuclear Information System (INIS)

Tang Xiuhuan; Bao Lihong; Li Hua; Wan Junsheng

2014-01-01

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

On the sequence of core-melt accidents: Fission product release, source terms and Chernobyl release

Energy Technology Data Exchange (ETDEWEB)

Albrecht, H

1986-01-01

There is a sketch of our ideas on the course of a core melt-out accident in a PWR. There is then a survey of the most important results on fission product release, which were obtained by experiments on the SASCHA melt-out plant. The 3rd part considers questions which are important for determining source terms for the environment and the last part contains some considerations on radioactivity release from the Chernobyl reactor.

Characteristics of the aerosols released to the environment after a severe PWR accident

International Nuclear Information System (INIS)

Lhiaubet, G.; Manesse, D.

1988-05-01

In the event of a postulated severe accident on a pressurized water reactor (PWR) involving fuel degradation, gases and aerosols containing radioactive products could be released, with short, medium and long term consequences for the population and the environment. Under such accident conditions, the ESCADRE code system, developed at IPSN (Institute for Nuclear Safety and Protection) can be used to calculate the properties of the substances released and, especially with the AEROSOLS/B2 code, the main characteristics of the aerosols (concentration, size distribution, composition). For conditions representative of severe PWR accidents, by varying different main parameters (structural material aerosols, steam condensation in the containment, etc...), indications are given on the range of characteristics of the aerosols (containing notably Cs, Te, Sr, Ru, etc...) released to the atmosphere. Information is also given on how more accurate data (especially on the chemical forms) will be obtainable in the framework of current or planned experimental programs (HEVA, PITEAS, PHEBUS PF, etc...) [fr

Experiments to quantify airborne release from packages with dispersible radioactive materials under accident conditions

Energy Technology Data Exchange (ETDEWEB)

Martens, R.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50667 Koeln (Germany); Koch, W.; Nolte, O. [Fraunhofer-Institut fuer Toxikologie und Experimentelle Medizin (ITEM), Nikolai-Fuchs-Str.1, 30625 Hannover (Germany)

2005-07-01

fraction may be adopted after a 9 m drop. Based on these experimentally determined release fractions for packages containing LSA-II material in powder form it can be concluded that the resulting inhalation dose of an individual in the vicinity of the accident location lies by more than one order of magnitude below the effective dose limit of 50 mSv. Thus, the limits specified in the Transport Regulations of the mass-related activity concentrations for LSA-II of 10{sup -4} A{sub 2}/g were confirmed as being conservative also for powdery, easily dispersible materials. (authors)

Release fraction of PWR after severe accidents. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

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

1996-03-01

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

Release fraction of PWR after severe accidents. Vol. 4

International Nuclear Information System (INIS)

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

1996-01-01

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

Risk analysis of releases from accidents during mid-loop operation at Surry

International Nuclear Information System (INIS)

Jo, J.; Lin, C.C.; Nimnual, S.; Mubayi, V.; Neymotin, L.

1992-11-01

Studies and operating experience suggest that the risk of severe accidents during low power operation and/or shutdown (LP/S) conditions could be a significant fraction of the risk at full power operation. Two studies have begun at the Nuclear Regulatory Commission (NRC) to evaluate the severe accident progression from a risk perspective during these conditions: One at the Brookhaven National Laboratory for the Surry plant, a pressurized water reactor (PWR), and the other at the Sandia National Laboratories for the Grand Gulf plant, a boiling water reactor (BWR). Each of the studies consists of three linked, but distinct, components: a Level I probabilistic risk analysis (PRA) of the initiating events, systems analysis, and accident sequences leading to core damage; a Level 2/3 analysis of accident progression, fuel damage, releases, containment performance, source term and consequences-off-site and on-site; and a detailed Human Reliability Analysis (HRA) of actions relevant to plant conditions during LP/S operations. This paper summarizes the approach taken for the Level 2/3 analysis at Surry and provides preliminary results on the risk of releases and consequences for one plant operating state, mid-loop operation, during shutdown

Main safety issues related to IPSN severe accident research

International Nuclear Information System (INIS)

LeComte, C.

1991-01-01

The work performed at IPSN concerning accident studies on nuclear installations is focused on the characterization of accidental sequences with three major aims: prevention, mitigation, and organization of counter-measures. As criteria to optimize all efforts made to improve nuclear safety, the radioactive dispersal in the environment must be quantified as function of internal and external radioactive products transfers. During the short-term phase of the accident, potential radioactive releases can be evaluated by the realistic code system ESCADRE. This system is validated by numerous analytical studies related to containment and fission product behavior. It will be further qualified by the results of the global experiments performed in the PHEBUS FP facility at IPSN

Modeling and analyses of postulated UF6 release accidents in gaseous diffusion plant

International Nuclear Information System (INIS)

Kim, S.H.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W.; Carter, J.C.; Dyer, R.H.

1995-10-01

Computer models have been developed to simulate the transient behavior of aerosols and vapors as a result of a postulated accident involving the release of uranium hexafluoride (UF 6 ) into the process building of a gaseous diffusion plant. UF 6 undergoes an exothermic chemical reaction with moisture (H 2 O) in the air to form hydrogen fluoride (HF) and radioactive uranyl fluoride (UO 2 F 2 ). As part of a facility-wide safety evaluation, this study evaluated source terms consisting of UO 2 F 2 as well as HF during a postulated UF 6 release accident in a process building. In the postulated accident scenario, ∼7900 kg (17,500 lb) of hot UF 6 vapor is released over a 5 min period from the process piping into the atmosphere of a large process building. UO 2 F 2 mainly remains as airborne-solid particles (aerosols), and HF is in a vapor form. Some UO 2 F 2 aerosols are removed from the air flow due to gravitational settling. The HF and the remaining UO 2 F 2 are mixed with air and exhausted through the building ventilation system. The MELCOR computer code was selected for simulating aerosols and vapor transport in the process building. MELCOR model was first used to develop a single volume representation of a process building and its results were compared with those from past lumped parameter models specifically developed for studying UF 6 release accidents. Preliminary results indicate that MELCOR predicted results (using a lumped formulation) are comparable with those from previously developed models

National practices in relation to severe accidents

International Nuclear Information System (INIS)

Soda, Kunihisa

1989-01-01

After the accidents at Three Mile Island and Chernobyl, many studies have been carried out on severe accidents by various organizations including IAEA and OECD/CSNI. In the present article, measures taken in different countries against severe accidents are outlined based on the results of these studies. In Sweden, policies for the management of a severe accident and reduction in the release of radioactive materials were established based on reports issued by the Atomic Energy Committee, which was set up after the Three Mile Island accident. The current policies require that filter vents be provided where necessary. France, following Sweden, adopted the use of filter vents. Operation procedures to be followed in the event of a severe accident have been established in the nation. The measures against severe accidents adopted in West Germany mainly focus on the weakening of the effects of accidents, and are not covered by the design standards. The use of filter vents are also required in Finland and Switzerland. In the U.S., a program for individual plant examination will be implemented over the three-year period beginning in 1989. Studies on measures against severe accidents seem to be performed also in the Soviet Union. (N.K.)

Massive radiological releases profoundly differ from controlled releases

International Nuclear Information System (INIS)

Pascucci-Cahen, Ludivine; Patrick, Momal

2013-01-01

In this article, the authors report identification and assessment of different types of costs associated with nuclear accidents. They first outline that these cost assessments must be as exhaustive or comprehensive as possible. While referring to past accidents, they define the different categories of costs: on-site costs (decontamination and dismantling, electricity not produced on the site), off-site costs (health costs, psychological costs, farming losses), image-related costs (impact on food and farm product exports, decrease of other exports), costs related to energy production, costs related to contaminated areas (refugees, lands). They give an assessment of a severe nuclear accident (i.e. an accident with important but controlled radiological releases) in France and outline that it would be a national catastrophe which could be however managed. They discuss the possible variations of the estimated costs. Then, they show that a major accident (i.e. an accident with massive radiological releases) in France would be an unmanageable European catastrophe because of the radiological consequences, of high economic costs, and of huge losses

Estimate of radionuclide release characteristics into containment under severe accident conditions

International Nuclear Information System (INIS)

Nourbakhsh, H.P.

1993-11-01

A detailed review of the available light water reactor source term information is presented as a technical basis for development of updated source terms into the containment under severe accident conditions. Simplified estimates of radionuclide release and transport characteristics are specified for each unique combination of the reactor coolant and containment system combinations. A quantitative uncertainty analysis in the release to the containment using NUREG-1150 methodology is also presented

The environmental impact of radioactive releases from accidents in nuclear power reactors

International Nuclear Information System (INIS)

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

1978-01-01

A survey of accidental releases of radioactivity from thermal and fast reactors is presented. Following a general discussion on the hazards involved, the nature of the environmental impact of radioactive releases is examined. This includes a brief review of the natural radiation background, the effect on human health of various levels of radiation and radioactivity, permissible and reference levels, and the type of hazards from both passing clouds of airbourne radioactive material and from ground deposited material. The problem of atmospheric dispersion and methods of calculations of radioactive materials in the atmosphere are examined in order for the consequences of accidental release to be analysed. National accidents and their environmental consequences are then examined. Finally there is a review of the risks to which man is always exposed because of his environment. Common and collective risks are also considered. Conclusions are reached as to the acceptibility or otherwise of the environmental impact of reactor accidents. (U.K.)

Benchmarking of fast-running software tools used to model releases during nuclear accidents

Energy Technology Data Exchange (ETDEWEB)

Devitt, P.; Viktorov, A., E-mail: Peter.Devitt@cnsc-ccsn.gc.ca, E-mail: Alex.Viktorov@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)

2015-07-01

Fukushima highlighted the importance of effective nuclear accident response. However, its complexity greatly impacted the ability to provide timely and accurate information to national and international stakeholders. Safety recommendations provided by different national and international organizations varied notably. Such differences can partially be attributed to different methods used in the initial assessment of accident progression and the amount of radioactivity release.Therefore, a comparison of methodologies was undertaken by the NEA/CSNI and its highlights are presented here. For this project, the prediction tools used by various emergency response organizations for estimating the source terms and public doses were examined. Those organizations that have a capability to use such tools responded to a questionnaire describing each code's capabilities and main algorithms. Then the project's participants analyzed five accident scenarios to predict the source term, dispersion of releases and public doses. (author)

Comparison of US/FRG accident condition models for HTGR fuel failure and radionuclide release

International Nuclear Information System (INIS)

Verfondern, K.

1991-03-01

The objective was to compare calculation models used in safety analyses in the US and FRG which describe fission product release behavior from TRISO coated fuel particles under core heatup accident conditions. The frist step performed is the qualitative comparison of both sides' fuel failure and release models in order to identify differences and similarities in modeling assumptions and inputs. Assumptions of possible particle failure mechanisms under accident conditions (SiC degradation, pressure vessel) are principally the same on both sides though they are used in different modeling approaches. The characterization of a standard (= intact) coated particle to be of non-releasing (GA) or possibly releasing (KFA/ISF) type is one of the major qualitative differences. Similar models are used regarding radionuclide release from exposed particle kernels. In a second step, a quantitative comparison of the calculation models was made by assessing a benchmark problem predicting particle failure and radionuclide release under MHTGR conduction cooldown accident conditions. Calculations with each side's reference method have come to almost the same failure fractions after 250 hours for the core region with maximum core heatup temperature despite the different modeling approaches of SORS and PANAMA-I. The comparison of the results of particle failure obtained with the Integrated Failure and Release Model for Standard Particles and its revision provides a 'verification' of these models in this sense that the codes (SORS and PANAMA-II, and -III, respectively) which were independently developed lead to very good agreement in the predictions. (orig./HP) [de

Radionuclide release calculations for selected severe accident scenarios

International Nuclear Information System (INIS)

Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A.

1990-08-01

This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. ''Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs

Operational intervention levels and related requirements on radiation monitoring during pre-release / release phase of an accident

International Nuclear Information System (INIS)

Carny, P.; Cabanekova, H

2003-01-01

In this paper authors discusses required outputs of emergency radiological monitoring in various phases of an accident and rationale of these requirements. In various phases of an accident various intervention levels are important and consequently various radiological quantities should be preferably measured. Distinguished tasks or aims of monitoring in different phases of accident have strong influence on methods of monitoring, instrumentation and capabilities of monitoring groups. Required tasks and outputs of monitoring are discussed

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

International Nuclear Information System (INIS)

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-01-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137 Cesium ( 137 Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132 Te- 132 I, 131 I, 134 Cs and 137 Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h −1 per initial 137 Cs deposition of 1000 kBq m −2 , whereas it was 100 μGy h −1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m −2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ( 134 Cs + 137 Cs) around Chernobyl and Fukushima-1, respectively

Proposal of the concept of selection of accidents that release large amounts of radioactive substances in the high temperature engineering test reactor

International Nuclear Information System (INIS)

Ono, Masato; Honda, Yuki; Takada, Shoji; Sawa, Kazuhiro

2015-01-01

In Position, construction and equipment of testing and research reactor to be subjected to the use standards for rules Article 53 (prevention of expansion of the accident to release a large amount of radioactive material) generation the frequency is a lower accident than design basis accident, when what is likely to release a large amount of radioactive material or radiation from the facility has occurred, and take the necessary measures in order to prevent the spread of the accident. There is provided a lower accident than frequency design basis accidents, for those that may release a large amount of radioactive material or radiation. (author)

Transport and release of fission products during nuclear reactor accident

International Nuclear Information System (INIS)

Lee, K.W.; Kuhlman, M.R.; Gieseke, J.A.

1984-01-01

This study represents the identification and formulation of a systematic, mechanistic approach to estimating source terms and the implementation of this approach through calculations of fission products release to the environment for a large PWR reactor under a selected set of accident conditions. The development and improvement of calculational procedures is an evolutionary process and in the long term must be verified through experimental studies. It is anticipated that as additional information is obtained the accuracy of predictions can be improved and uncertainties reduced. Transport and deposition of radionuclides were found to be quite dependent on the accident sequences and the corresponding thremal hydraulic conditions. Reduced temperatures led to increased deposition of vapor species, and reduced flow rates to increased aerosol deposition. It is to be recognized that the estimates of release fractions are subject to uncertainties in the data and computer models employed in the calculations and are expected to have been influenced by assumptions regarding plant geometry, thermal hydraulics, deposition mechanisms, and sequence events. The effects of these assumptions will be investigated as this study continues. (Author)

Evaluation of containment failure modes and fission product releases during core meltdown accidents in a BWR with a Mark III containment

International Nuclear Information System (INIS)

Ludewig, H.; Yu, W.S.; Jaung, R.; Pratt, W.T.

1985-01-01

An assessment is described of potential failure modes and fission product releases for a large number of postulated core meltdown accidents in a BWR with a Mark III containment. For this containment design, the most important failure mode was found to be due to hydrogen related phenomena. A one-dimensional lumped parameter computer code has been developed and used to determine the probability of various hydrogen phenomena for a range of postulated core meltdown sequences. Potential containment loads have been estimated and compared against the containment capacity to determine the probability of containment failure. The fission product release assessment began by using the MARCH/CORRAL system of codes with key input parameters varied over a reasonable range. The parameters relate to primary system retention, re-emission, pool scrubbing, and fission product release in-vessel vs ex-vessel. The final step used more mechanistic calculations based on the system of codes recently developed under sponsorship of the Accident Source Term Program Office, NRC, and compares these predictions with the range of releases calculated in the sensitivity study

Protective action evaluation, Part 1. Effectiveness of sheltering as a protective action against nuclear accidents involving gaseous releases

International Nuclear Information System (INIS)

Anno, G.H.; Dore, M.A.

1978-04-01

In an airborne release of radioactive material from a nuclear power plant accident, sheltering of individuals is of importance in emergency protective action planning. An analysis to estimate the effectiveness or benefit that might be derived from sheltering is described. The objective of this effort is the development of sheltering effectiveness information for those responsible for formulating required emergency plans for nuclear power plant siting. Shelter effectiveness is specifically defined as the dose reduction factor (DRF). DRF estimates for different conditions of source release, shelter structure assumptions, and operational time parameters are made for both whole-body and thyroid doses separately, based on a single-compartment structural model of the time-varying outside and inside gaseous radionuclide sources of krypton, zenon, and iodine. Design basis accident (DBA) assumptions are made for the gaseous radionuclide release. The magnitude of the release and dose estimates are based on radionuclide data from The Reactor Safety Study (WASH-1400). Source release time and duration assumptions are related to release categories PWR 1, PWR 3, and PWR 4, for which release times range from 1.5 to 2.5 hr and the release duration ranges from 0.5 to 3 hr. The basic shelter model characteristics considered are gamma ray attentuation, source geometry, gaseous fission-product ingress, and air change rate. Temporal parameters considered are source release time and duration, cloud travel time, and time spent in the shelter structure. Also, the analysis of shelter effectiveness is based on a time-frame model, which can be conveniently related to other operational times important for emergency planning. In addition to developing shelter-effectiveness estimates parametrically, the advantage of exiting and evacuating the vicinity of the shelter area after some initial time in the shelter is analyzed from the standpoint of the DRF and temporal considerations

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

International Nuclear Information System (INIS)

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

1979-10-01

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

Biomass accident investigations – missed opportunities for learning and accident prevention

DEFF Research Database (Denmark)

Hedlund, Frank Huess

2017-01-01

The past decade has seen a major increase in the production of energy from biomass. The growth has been mirrored in an increase of serious biomass related accidents involving fires, gas explosions, combustible dust explosions and the release of toxic gasses. There are indications that the number...... of bioenergy related accidents is growing faster than the energy production. This paper argues that biomass accidents, if properly investigated and lessons shared widely, provide ample opportunities for improving general hazard awareness and safety performance of the biomass industry. The paper examines...... selected serious accidents involving biogas and wood pellets in Denmark and argues that such opportunities for learning were missed because accident investigations were superficial, follow-up incomplete and information sharing absent. In one particularly distressing case, a facility saw a repeat accident...

Radionuclide release calculations for selected severe accident scenarios. PWR, ice condenser design

Energy Technology Data Exchange (ETDEWEB)

Denning, R S; Gieseke, J A; Cybulskis, P; Lee, K W; Jordan, H; Curtis, L A; Kelly, R F; Kogan, V; Schumacher, P M

1986-07-01

This report presents results of analyses of the environmental releases of fission products (source terms) for severe accident scenarios in a pressurized water reactor with an ice-condenser containment. The analyses were performed to support the Severe Accident Risk Reduction/Risk Rebaselining Program (SARRP) which is being undertaken for the U.S. Nuclear Regulatory Commission by Sandia National Laboratories. In the SARRP program, risk estimates are being generated for a number of reference plant designs. The Sequoyah Plant has been used in this study as an example of a PWR ice-condenser plant. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

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

International Nuclear Information System (INIS)

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

1980-01-01

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

The terrestrial environmental dynamics of radioactive nuclides released by the Fukushima nuclear accident

International Nuclear Information System (INIS)

Furukawa, Jun

2014-01-01

Research into environmental dynamics of radioactive nuclides released by the Fukushima nuclear accident, especially radiocesium 137 Cs (half-life, 30.1 years), is highly focused especially on diffusion processes of radiocesium into ecosystems, which is high-priority knowledge. Because of relatively sparse knowledge about the reallocation of radiocesium contained in organic matter in terrestrial ecosystems, the effects of diffused rediocesium into ecosystem cannot be accurately estimated. In this article, the terrestrial environmental dynamics of radiocesium mainly in the processes of plant uptake and the possibility of release from plants will be discussed. Plants uptake minerals from soil and these minerals are likewise ingested by animals that feed on plants, including humans. Therefore one of the main gateways of radiocesium into ecosystem is via plants. From the viewpoint of human dietary consumption, rice contamination with radiocesium has been energetically investigated and useful data are accumulating. Processes of radiocesium uptake mechanisms by plants are being researched using legumes, e.g. soybean. Speculation on the possibility of radiocesium release into forest atmosphere via plant activity will be introduced. (author)

Tellurium chemistry, tellurium release and deposition during the TMI-2 accident

International Nuclear Information System (INIS)

Vinjamuri, K.; Sallach, R.A.; Osetek, D.J.; Hobbins, R.R.; Akers, D.W.

1985-01-01

This paper presents the chemistry and estimated behavior of tellurium during and after the accident at Three Mile Island Unit-2. The discussion of tellurium behavior is based on all available measurement data for /sup 129m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te, and 130 Te), and best estimate calculations of tellurium release and transport. Results from Oak Ridge National Laboratory (ORNL) tests, Power Burst Facility (PBF) Severe Fuel Damage Tests at Idaho National Engineering Laboratory (INEL) and SASCHA tests from Karlsruhe, W. Germany are compared with calculated release fractions and samples taken from TMI Unit-2. It is concluded that very little tellurium was released and transported from the TMI-2 core, probably as a result of holdup by zircaloy cladding and other structural materials. 37 refs., 12 figs., 4 tabs

Tellurium chemistry, tellurium release and deposition during the TMI-2 accident

International Nuclear Information System (INIS)

Vinjamuri, K.; Sallach, R.A.; Osetek, D.J.; Hobbins, R.R.; Akers, D.W.

1985-08-01

This report presents the chemistry and estimated behavior of tellurium during and after the accident at Three Mile Island Unit-2. The discussion of tellurium behavior is based on all available measurement data for /sup 129 m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te, and 130 Te), and best estimate calculations of tellurium release and transport. Results from Oak Ridge National Laboratory (ORNL) tests, Power Burst Facility (PBF) Severe Fuel Damage Tests at Idaho National Engineering Laboratory (INEL) and SASCHA tests from Karlsruhe, W. Germany are compared with calculated release fractions and samples taken from TMI Unit-2. It is concluded that very little tellurium was released and transported from the TMI-2 core, probably as a result of holdup by zircaloy cladding and other structural materials. 39 refs., 24 figs., 17 tabs

Assessment of fission product release from the reactor containment building during severe core damage accidents in a PWR

International Nuclear Information System (INIS)

Fermandjian, J.; Evrard, J.M.; Generino, G.

1984-07-01

Fission product releases from the RCB associated with hypothetical core-melt accidents ABβ, S 2 CDβ and TLBβ in a PWR-900 MWe have been performed using French computer codes (in particular, the JERICHO Code for containment response analysis and AEROSOLS/B1 for aerosol behavior in the containment) related to thermalhydraulics and fission product behavior in the primary system and in the reactor containment building

Techniques to limit gaseous releases in case of reactor accident. Choice criteria - present solutions

International Nuclear Information System (INIS)

Billard, Francois; Lavie, Jean-Marie

1964-10-01

Within the frame of the study of radiological risks associated with a reactor accident in order to define the required responses, this study comprises, on the one hand, an analysis of the different accident types in order to select typical accidents, and on the other hand, a site-based analysis to define the maximum admissible radioactivity release for a given site. The determination of minimum required coefficient of risk reduction results from a compromise between the choice of reactor configuration type and the efficiency of purification devices, while taking into account minimum characteristics of the enclosure mechanical strength, local release conditions, and nature of gaseous effluents to be processed. After a review of available containment techniques, the author applies this analysis method to the different French reactor types. He gives a brief description of adopted solutions for the most typical French reactors in terms of characteristics of venting and filtration devices. As data quality is a crucial requirement, the author outlines the need for further studies regarding fission product emission and transfer, the purification of gaseous effluents and their diffusion in the atmosphere [fr

HOTSPOT, Field Evaluation of Radiation Release from Nuclear Accident

International Nuclear Information System (INIS)

2001-01-01

1 - Description of program or function: The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes are a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. HOTSPOT programs are reasonably accurate for a timely initial assessment. More importantly, HOTSPOT codes produce a consistent output for the same input assumptions and minimize the probability of errors associated with reading a graph incorrectly or scaling a universal nomogram during an emergency. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Other programs deal with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. Additional programs estimate the dose commitment from inhalation of any one of the radionuclides listed in the database of radionuclides, calibrate a radiation survey instrument for ground survey measurements, and screening of plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Version 8 allows users to add their own custom radionuclide library and to create custom radionuclide mixtures. It also includes wet deposition to approximate the enhanced plume depletion and ground deposition due to the effects of rain. Additional release geometry options for TRITIUM RELEASE and GENERAL PLUME were added, as well as several other enhancements and improvements. See info (f1) from the main HOTSPOT menu for additional

Trend of elevator-related accidents in tehran.

Science.gov (United States)

Khaji, Ali; Ghodsi, Syyed Mohammad

2014-06-01

Elevator-related accidents are uncommon, but can cause significant injury. However, little data exist on these types of accidents. To compile and analyze accident data involving elevators in an effort to eliminate or at least significantly reduce such accidents. In this retrospective study we investigated 1,819 cases of elevator-related accidents during a four-year period (1999-2003) in Tehran. The data were obtained from the Tehran Safety Services & Fire Fighting Organization (TSFO) that is officially and solely responsible to conduct rescue missions of civilians in Tehran. The number of elevator accidents has increased steadily during the four year study period. During these four years there was a positive upward trend for serious injuries and mortality resulting from elevator accidents. Technical problems were the main cause with 74.5%, followed by power loss and overcapacity riding with 11.5% and 7.9% respectively. Sixty-three individuals sustained serious injury and 15 people died as a result of elevator accidents. The number of accidents was significantly higher in summer (x2=18.32, P=0.032) and a considerable proportion of incidences (54%, 947 cases out of 1819) occurred between 5 and 12 pm. Establishment of an organization to inspect the settings, maintenance, and repair of elevators is necessary.

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

Woodworking injuries: a comparative study of work-related and hobby-related accidents.

Science.gov (United States)

Loisel, F; Bonin, S; Jeunet, L; Pauchot, J; Tropet, Y; Obert, L

2014-10-01

The primary objective of this study was to describe the injury characteristics and demographics of patients injured during woodworking activities, upon their arrival to the emergency department in a regional of France where this industry is prevalent. The secondary objective was to compare patient and injury characteristics for work-related and hobby-related accidents. A cohort of 87 patients who had suffered a woodworking accident over a two-year period was evaluated; 79 were available for follow-up. The context and circumstances of the accident, nature and location of the injuries and patient demographics were recorded. Hobby-related accidents accounted for two-thirds of the accidents (51/79). Most of the injured workers were either loggers (35%) or carpenters (46%). The hand was injured in 53 cases (67%). Work-related accidents resulted in significantly more serious consequences in terms of hospital stay, work stoppage, resumption of work or retraining than hobby-related accidents. For the workplace accidents, 86% occurred on new machines; more than 25% of the machines involved in accidents at home were over 15 years. Sixty-eight per cent of workers were wearing their safety gear, while only 31% of those injured during recreational woodworking wore the appropriate gear. Several elements of prevention should be improved: information about the need to maintain the equipment, protect the worker with suitable clothing, and learn which maneuvers are considered hazardous. Safety gear should be regularly inspected in the workplace. Copyright © 2014. Published by Elsevier SAS.

Aerosols released in accidents in reprocessing plants

International Nuclear Information System (INIS)

Ballinger, M.Y.; Owczarski, P.C.; Hashimoto, K.; Nishio, G.; Jordan, S.; Lindner, W.

1987-01-01

For analyzing the thermodynamic and radiological consequences of solvent fire accidents in reprocessing plants, intensive investigations on burning contaminated condensible liquids were performed at Kernforschungszentrum Karlsruhe (KfK), Pacific Northwest Laboratory (PNL), and Japan Atomic Energy Research Institute (JAERI). In small- and large-scale tests, KfK studied the behavior of kerosene, tributyl phosphate, HNO 3 mixture fires in open air and closed containments. The particle release from uranium-contaminated pool fires was investigated. Different filter devices were tested. For analyzing fires, PNL has developed the FIRIN computer code and has generated small-scale fire data in support of that code. The results of the experiments in which contaminated combustible liquids were burned demonstrate the use of the FIRIN code in simulating a solvent fire in a nuclear reprocessing plant. To demonstrate the safety evaluation of a postulated solvent fire in an extraction process of a reprocessing pant, JAERI conducted large-scale fire tests. Behavior of solvent fires in a cell and the integrity of high-efficiency particulate air (HEPA) filters due to smoke plugging were investigated. To evaluate confinement of radioactive materials released from the solvent fire, the ventilation systems with HEPA filters were tested under postulated fire conditions

Consequences in Norway of a hypothetical accident at Sellafield: Potential release - transport and fallout

International Nuclear Information System (INIS)

Ytre-Eide, M. A.; Standring, W.J.F.; Amundsen, I.; Sickel, M.; Liland, A.; Saltbones, J.; Bartnicki, J.; Haakenstad, H.; Salbu, B.

2009-03-01

This report focuses on transport and fallout from 'worst-case' scenarios based on a hypothetical accident at the B215 facility for storing Highly Active Liquors (HAL) at Sellafield. The scenarios involve an atmospheric release of between 0.1-10 % of the total HAL inventory; only transport and fallout of 137 Cs is considered in this case study. Simulations resulted in between 0.1-50 times the maximum 137 Cs fallout experienced in the most contaminated areas in Norway after the Chernobyl accident. (Author)

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

International Nuclear Information System (INIS)

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

1980-01-01

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

EMERALD, Radiation Release and Dose after PWR Accident for Design Analysis and Operation Analysis

International Nuclear Information System (INIS)

Brunot, W.K.; Fray, R.R.; Gillespie, S.G.

1988-01-01

1 - Description of problem or function: The EMERALD program is designed for the calculation of radiation releases and exposures resulting from abnormal operation of a large pressurized water reactor (PWR). The approach used in EMERALD is similar to an analog simulation of a real system. Each component or volume in the plant which contains a radioactive material is represented by a subroutine which keeps track of the production, transfer, decay and absorption of radioactivity in that volume. During the course of the analysis of an accident, activity is transferred from subroutine to subroutine in the program as it would be transferred from place to place in the plant. For example, in the calculation of the doses resulting from a loss-of-coolant accident the program first calculates the activity built up in the fuel before the accident, then releases some of this activity to the containment volume. Some of this activity is then released to the atmosphere. The rates of transfer, leakage, production, cleanup, decay, and release are read in as input to the program. Subroutines are also included which calculate the on-site and off-site radiation exposures at various distances for individual isotopes and sums of isotopes. The program contains a library of physical data for the twenty-five isotopes of most interest in licensing calculations, and other isotopes can be added or substituted. Because of the flexible nature of the simulation approach, the EMERALD program can be used for most calculations involving the production and release of radioactive materials during abnormal operation of a PWR. These include design, operational, and licensing studies. 2 - Method of solution - Explicit solutions of first-order linear differential equations are included. In addition, a subroutine is provided which solves a set of simultaneous linear algebraic equations. 3 - Restrictions on the complexity of the problem - Maxima of: 25 isotopes, 7 time periods, 15 volumes or components, 10

Severe accident progression perspectives based on IPE results

International Nuclear Information System (INIS)

Lehner, J.R.; Lin, C.C.; Pratt, W.T.; Drouin, M.

1996-01-01

Accident progression perspectives were gathered from the level 2 PRA analyses (the analysis of the accident after core damage has occurred involving the containment performance and the radionuclide release from the containment) described in the IPE submittals. Insights related to the containment failure modes, the releases associated with those failure modes, and the factors responsible for the types of containment failures and release sizes reported were obtained. Complete results are discussed in NUREG-1560 and summarized here

Trend of Elevator-Related Accidents in Tehran

Directory of Open Access Journals (Sweden)

Ali Khaji

2014-06-01

Full Text Available Background:   Elevator-related accidents are uncommon, but can cause significant injury. However, little data exist on these types of accidents. To compile and analyze accident data involving elevators in an effort to eliminate or at least significantly reduce such accidents. Methods: In this retrospective study we investigated 1,819 cases of elevator-related accidents during a four-year period (1999-2003 in Tehran. The data were obtained from the Tehran Safety Services & Fire Fighting Organization (TSFO that is officially and solely responsible to conduct rescue missions of civilians in Tehran. Results: The number of elevator accidents has increased steadily during the four year study period. During these four years here was a positive upward trend for serious injuries and mortality resulting from elevator accidents. Technical problems were the main cause with 74.5%, followed by power loss and overcapacity riding with 11.5% and 7.9%respectively. Sixty-three individuals sustained serious injury and 15 people died as a result of elevator accidents. The number of accidents was significantly higher in summer (x2=18.32, P=0.032 and a considerable proportion of incidences (54%, 947 cases out of 1819 occurred between 5 and 12 pm. Conclusions: Establishment of an organization to inspect the settings, maintenance, and repair of elevators is necessary

Radionuclide release calculations for selected severe accident scenarios. Volume 3. PWR, subatmospheric containment design

International Nuclear Information System (INIS)

Denning, R.S.; Gieseke, J.A.; Cybulskis, P.; Lee, K.W.; Jordan, H.; Curtis, L.A.; Kelly, R.F.; Kogan, V.; Schumacher, P.M.

1986-07-01

This report presents results of analyses of the enviromental releases of fission products (source terms) for severe accident scenarios in a pressurized water reactor with a subatmospheric containment design. The analyses were performed to support the Severe Accident Risk Reduction/Risk Rebaselining Program (SARRP) which is being undertaken for the US Nuclear Regulatory Commission by Sandia National Laboratories. In the SARRP program, risk estimates are being generated for a number of reference plant designs. the Surry plant has been used in this study as the reference plant for a subatmospheric design

Nuclear fuel in a reactor accident.

Science.gov (United States)

Burns, Peter C; Ewing, Rodney C; Navrotsky, Alexandra

2012-03-09

Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.

Unsolved issues related to thermal-hydraulics in the suppression chamber during Fukushima Daiichi accident progressions

International Nuclear Information System (INIS)

Mizokami, Shinya; Yamada, Daichi; Honda, Takeshi; Yamauchi, Daisuke; Yamanaka, Yasunori

2016-01-01

On 11 March 2011, the Great East Japan Earthquake and Tsunami hit the Fukushima Daiichi Nuclear Power Station. The Fukushima Daiichi Units 1-3 lost all DC and AC power supplies, which set in motion a chain of events that led to releases of radioactivity to the environment. Since then, TEPCO has made many efforts to investigate the accident progressions and the status of the reactors and containment vessels. However, there still exist several tens of unsolved issues to be investigated for the fully understanding of the accident. In this paper, we introduce the unsolved issues related to thermal-hydraulics in the suppression chamber during the Fukushima Daiichi accident progressions. Especially, in Units 2 and 3, there are possibilities that thermal stratification inside their suppression chambers played an important role. It is important that these phenomena are addressed following both theoretical and experimental approaches as support to severe accident simulations. (author)

French practice for assessing the fission product releases from the containment during a PWR severe accident

International Nuclear Information System (INIS)

Duco, J.; Dufresne, J.; L'homme, A.

1988-10-01

French safety philosophy as concerns severe PWR accidents has already been outlined by the Director of CEA/IPSN in an article published in ''Nuclear Safety''. Therefore the present paper will focus on: a) the French reference source terms, as used for elaborating ultimate emergency procedures on PWRs and for emergency planning; b) the methods currently developed for more realistic assessments of the release of fission products during a severe accident

Sensitivity Analysis of Dousing Spray Trip on Radioactive Release in Pressure Tube Rupture Accident with Both End Fitting Failures

Energy Technology Data Exchange (ETDEWEB)

Jang, M. S.; Kang, H. S; Kim, S. R. [NESS, Daejeon (Korea, Republic of)

2015-10-15

We analyzed the sensitivity analysis of dousing spray trip conditions on radioactive release. In terms of conservativeness, the set 1 trip would be more appropriate in RR analysis than set 2 trip, which is the general condition of RR analysis. Radioactive releases from the containment building is related to containment air pressure, which increases by the coolant discharge from loss of coolant accident and the actuation conditions of dousing spray and so on. In LOCA analysis, the dousing spray trip conditions are set for the analysis objectives; for peak pressure (PP), for pressure signal (PS), for radioactive release (RR) and etc. In RR analysis, we would determine the dousing spray trip condition to increase radioactive release to the public for conservatism. Therefore, we carried out the sensitivity analysis of dousing spray trip condition on radioactive release from containment building using GOTHIC and SMART program for CANDU.

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

Energy Technology Data Exchange (ETDEWEB)

None

1977-03-01

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

Analysis on relation between safety input and accidents

Institute of Scientific and Technical Information of China (English)

YAO Qing-guo; ZHANG Xue-mu; LI Chun-hui

2007-01-01

The number of safety input directly determines the level of safety, and there exists dialectical and unified relations between safety input and accidents. Based on the field investigation and reliable data, this paper deeply studied the dialectical relationship between safety input and accidents, and acquired the conclusions. The security situation of the coal enterprises was related to the security input rate, being effected little by the security input scale, and build the relationship model between safety input and accidents on this basis, that is the accident model.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Radioactivity release vs probability for a steam generator tube rupture accident

International Nuclear Information System (INIS)

Buslik, A.J.; Hall, R.E.

1978-01-01

A calculation of the probability of obtaining various radioactivity releases from a steam generator tube rupture (SGTR) is presented. The only radioactive isotopes considered are Iodine-131 and Xe-133. The particular accident path considered consists of a double-ended guillotine SGTR followed by loss of offsite power (LOSP). If there is no loss of offsite power, and no system fault other than the SGTR, it is judged that the consequences will be minimal, since the amount of iodine released through the condenser air ejector is expected to be quite small; this is a consequence of the fact that the concentration of iodine in the vapor released from the condenser air ejector is very small compared to that dissolved in the condensate water. In addition, in some plants the condenser air ejector flow is automatically diverted to containment or a high-activity alarm. The analysis presented here is for a typical Westinghouse PWR such as described in RESAR-3S

ORNL experiments to characterize fuel release from the reactor primary containment in severe LMFBR accidents

International Nuclear Information System (INIS)

Wright, A.L.; Kress, T.S.; Smith, A.M.

1980-01-01

This paper presents results from aerosol source term experiments performed in the ORNL Aerosol Release and Transport (ART) Program sponsored by the US NRC. The tests described were performed to provide information on fuel release from an LMFBR primary containment as a result of a hypothetical core-disruptive accident (HCDA). The release path investigated in these tests assumes that a fuel/sodium bubble is formed after disassembly that transports fuel and fission products through the sodium coolant and cover gas to be relased into the reactor secondary containment. Due to the excellent heat transfer characteristics of the sodium, there is potential for large attenuation of the maximum release

Characterization and chemistry of fission products released from LWR fuel under accident conditions

International Nuclear Information System (INIS)

Norwood, K.S.; Collins, J.L.; Osborne, M.F.; Lorenz, R.A.; Wichner, R.P.

1984-01-01

Segments from commercial LWR fuel rods have been tested at temperatures between 1400 and 2000 0 C in a flowing steam-helium atmosphere to simulate severe accident conditions. The primary goals of the tests were to determine the rate of fission product release and to characterize the chemical behavior. This paper is concerned primarily with the identification and chemical behavior of the released fission products with emphasis on antimony, cesium, iodine, and silver. The iodine appeared to behave primarily as cesium iodide and the antimony and silver as elements, while cesium behavior was much more complex. 17 refs., 7 figs., 1 tab

Safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release

International Nuclear Information System (INIS)

Pointner, W.; Broecker, A.

2012-01-01

The report on safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release covers the following issues: assessment of the relevant status for PWR, evaluation of the national and international (USA, Canada, France) status, actualization of recommendations, transferability from PWR to BWR. Generic studies on the core cooling capability in case of insulation material release in BWR-type reactors were evaluated.

Statistical evaluation of design-error related accidents

International Nuclear Information System (INIS)

Ott, K.O.; Marchaterre, J.F.

1980-01-01

In a recently published paper (Campbell and Ott, 1979), a general methodology was proposed for the statistical evaluation of design-error related accidents. The evaluation aims at an estimate of the combined residual frequency of yet unknown types of accidents lurking in a certain technological system. Here, the original methodology is extended, as to apply to a variety of systems that evolves during the development of large-scale technologies. A special categorization of incidents and accidents is introduced to define the events that should be jointly analyzed. The resulting formalism is applied to the development of the nuclear power reactor technology, considering serious accidents that involve in the accident-progression a particular design inadequacy

Modeling of in-vessel fission product release including fuel morphology effects for severe accident analyses

International Nuclear Information System (INIS)

Suh, K.Y.

1989-10-01

A new in-vessel fission product release model has been developed and implemented to perform best-estimate calculations of realistic source terms including fuel morphology effects. The proposed bulk mass transfer correlation determines the product of fission product release and equiaxed grain size as a function of the inverse fuel temperature. The model accounts for the fuel-cladding interaction over the temperature range between 770 K and 3000 K in the steam environment. A separate driver has been developed for the in-vessel thermal hydraulic and fission product behavior models that were developed by the Department of Energy for the Modular Accident Analysis Package (MAAP). Calculational results of these models have been compared to the results of the Power Burst Facility Severe Fuel Damage tests. The code predictions utilizing the mass transfer correlation agreed with the experimentally determined fractional release rates during the course of the heatup, power hold, and cooldown phases of the high temperature transients. Compared to such conventional literature correlations as the steam oxidation model and the NUREG-0956 correlation, the mass transfer correlation resulted in lower and less rapid releases in closer agreement with the on-line and grab sample data from the Severe Fuel Damage tests. The proposed mass transfer correlation can be applied for best-estimate calculations of fission products release from the UO 2 fuel in both nominal and severe accident conditions. 15 refs., 10 figs., 2 tabs

Preliminary Study for Application of the New Safety Goal related with the Limitation of Cs-137 release

Energy Technology Data Exchange (ETDEWEB)

Seo, Mi Ro; Shin, Tae Young [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

environment for the representative accident sequence assessed to find the method that the amount of Cs-137 released can be reduced using MAAP code. However, according to the MAAP calculation even though it is performed only for the one STC, it can be expected that the amount of Cs-137 released to the environment for each of all STCs is over 1,000TBq. Therefore, it is necessary to consider the approach from the aspect of PSA model. In the Level 2 PSA model, the improvement effects is so limited because of the uncertainties related with the severe accident phenomena and the difficulties in the installation of new facilities.

Preliminary Study for Application of the New Safety Goal related with the Limitation of Cs-137 release

International Nuclear Information System (INIS)

Seo, Mi Ro; Shin, Tae Young

2016-01-01

environment for the representative accident sequence assessed to find the method that the amount of Cs-137 released can be reduced using MAAP code. However, according to the MAAP calculation even though it is performed only for the one STC, it can be expected that the amount of Cs-137 released to the environment for each of all STCs is over 1,000TBq. Therefore, it is necessary to consider the approach from the aspect of PSA model. In the Level 2 PSA model, the improvement effects is so limited because of the uncertainties related with the severe accident phenomena and the difficulties in the installation of new facilities

Probabilistic Approach to Conditional Probability of Release of Hazardous Materials from Railroad Tank Cars during Accidents

Science.gov (United States)

2009-10-13

This paper describes a probabilistic approach to estimate the conditional probability of release of hazardous materials from railroad tank cars during train accidents. Monte Carlo methods are used in developing a probabilistic model to simulate head ...

A model for the release, dispersion and environmental impact of a postulated reactor accident from a submerged commercial nuclear power plant

Science.gov (United States)

Bertch, Timothy Creston

1998-12-01

Nuclear power plants are inherently suitable for submerged applications and could provide power to the shore power grid or support future underwater applications. The technology exists today and the construction of a submerged commercial nuclear power plant may become desirable. A submerged reactor is safer to humans because the infinite supply of water for heat removal, particulate retention in the water column, sedimentation to the ocean floor and inherent shielding of the aquatic environment would significantly mitigate the effects of a reactor accident. A better understanding of reactor operation in this new environment is required to quantify the radioecological impact and to determine the suitability of this concept. The impact of release to the environment from a severe reactor accident is a new aspect of the field of marine radioecology. Current efforts have been centered on radioecological impacts of nuclear waste disposal, nuclear weapons testing fallout and shore nuclear plant discharges. This dissertation examines the environmental impact of a severe reactor accident in a submerged commercial nuclear power plant, modeling a postulated site on the Atlantic continental shelf adjacent to the United States. This effort models the effects of geography, decay, particle transport/dispersion, bioaccumulation and elimination with associated dose commitment. The use of a source term equivalent to the release from Chernobyl allows comparison between the impacts of that accident and the postulated submerged commercial reactor plant accident. All input parameters are evaluated using sensitivity analysis. The effect of the release on marine biota is determined. Study of the pathways to humans from gaseous radionuclides, consumption of contaminated marine biota and direct exposure as contaminated water reaches the shoreline is conducted. The model developed by this effort predicts a significant mitigation of the radioecological impact of the reactor accident release

The total release of xenon-133 from the Fukushima Dai-ichi nuclear power plant accident

International Nuclear Information System (INIS)

Stohl, Andreas; Seibert, Petra; Wotawa, Gerhard

2012-01-01

The accident at the Fukushima Dai-ichi nuclear power plant (FD-NPP) on 11 March 2011 released large amounts of radioactivity into the atmosphere. We determine the total emission of the noble gas xenon-133 ( 133 Xe) using global atmospheric concentration measurements. For estimating the emissions, we used three different methods: (i) using a purely observation-based multi-box model, (ii) comparisons of dispersion model results driven with GFS meteorological data with the observation data, and (iii) such comparisons with the dispersion model driven by ECMWF data. From these three methods, we have obtained total 133 Xe releases from FD-NPP of (i) 16.7 ± 1.9 EBq, (ii) 14.2 ± 0.8 EBq, and (iii) 19.0 ± 3.4 EBq, respectively. These values are substantially larger than the entire 133 Xe inventory of FD-NPP of about 12.2 EBq derived from calculations of nuclear fuel burn-up. Complete release of the entire 133 Xe inventory of FD-NPP and additional release of 133 Xe due to the decay of iodine-133 ( 133 I), which can add another 2 EBq to the 133 Xe FD-NPP inventory, is required to explain the atmospheric observations. Two of our three methods indicate even higher emissions, but this may not be a robust finding given the differences between our estimates. - Highlights: ► We determine the total release of xenon-133 from the Fukushima nuclear accident. ► We used global measurements and a box model, as well as dispersion model estimates. ► Total 133 Xe release is about 14.2-19 EBq, more than Fukushima 133 Xe inventory. ► Additional release of iodine-133 and decay into 133 Xe needed to explain results.

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.

Accidents at nuclear power plants

International Nuclear Information System (INIS)

Anon.

1979-01-01

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

MELCOR assessment of sequential severe accident mitigation actions under SGTR accident

International Nuclear Information System (INIS)

Choi, Wonjun; Jeon, Joongoo; Kim, Nam Kyung; Kim, Sung Joong

2017-01-01

The representative example of the severe accident studies using the severe accident code is investigation of effectiveness of developed severe accident management (SAM) strategy considering the positive and adverse effects. In Korea, some numerical studies were performed to investigate the SAM strategy using various severe accident codes. Seo et.al performed validation of RCS depressurization strategy and investigated the effect of severe accident management guidance (SAMG) entry condition under small break loss of coolant accident (SBLOCA) without safety injection (SI), station blackout (SBO), and total loss of feed water (TLOFW) scenarios. The SGTR accident with the sequential mitigation actions according to the flow chart of SAMG was simulated by the MELCOR 1.8.6 code. Three scenariospreventing the RPV failure were investigated in terms of fission product release, hydrogen risk, and the containment pressure. Major conclusions can be summarized as follows: (1) According to the flow chart of SAMG, RPV failure can be prevented depending on the method of RCS depressurization. (2) To reduce the release of fission product during the injecting into SGs, a temporary opening of SDS before the injecting into SGs was suggested. These modified sequences of mitigation actions can reduce the release of fission product and the adverse effect of SDS.

Analytics of Radioactive Materials Released in the Fukushima Daiichi Nuclear Accident

Energy Technology Data Exchange (ETDEWEB)

Egarievwe, Stephen U. [Nuclear Engineering and Radiological Science Center, Alabama A and M University, Huntsville, AL (United States); Nuclear Engineering Department, University of Tennessee, Knoxville, TN (United States); Coble, Jamie B.; Miller, Laurence F. [Nuclear Engineering Department, University of Tennessee, Knoxville, TN (United States)

2015-07-01

The 2011 Fukushima Daiichi nuclear accident in Japan resulted in the release of radioactive materials into the atmosphere, the nearby sea, and the surrounding land. Following the accident, several meteorological models were used to predict the transport of the radioactive materials to other continents such as North America and Europe. Also of high importance is the dispersion of radioactive materials locally and within Japan. Based on the International Atomic Energy Agency (IAEA) Convention on Early Notification of a nuclear accident, several radiological data sets were collected on the accident by the Japanese authorities. Among the radioactive materials monitored, are I-131 and Cs-137 which form the major contributions to the contamination of drinking water. The radiation dose in the atmosphere was also measured. It is impractical to measure contamination and radiation dose in every place of interest. Therefore, modeling helps to predict contamination and radiation dose. Some modeling studies that have been reported in the literature include the simulation of transport and deposition of I-131 and Cs-137 from the accident, Cs-137 deposition and contamination of Japanese soils, and preliminary estimates of I-131 and Cs-137 discharged from the plant into the atmosphere. In this paper, we present statistical analytics of I-131 and Cs-137 with the goal of predicting gamma dose from the Fukushima Daiichi nuclear accident. The data sets used in our study were collected from the IAEA Fukushima Monitoring Database. As part of this study, we investigated several regression models to find the best algorithm for modeling the gamma dose. The modeling techniques used in our study include linear regression, principal component regression (PCR), partial least square (PLS) regression, and ridge regression. Our preliminary results on the first set of data showed that the linear regression model with one variable was the best with a root mean square error of 0.0133 μSv/h, compared

Analytics of Radioactive Materials Released in the Fukushima Daiichi Nuclear Accident

International Nuclear Information System (INIS)

Egarievwe, Stephen U.; Coble, Jamie B.; Miller, Laurence F.

2015-01-01

The 2011 Fukushima Daiichi nuclear accident in Japan resulted in the release of radioactive materials into the atmosphere, the nearby sea, and the surrounding land. Following the accident, several meteorological models were used to predict the transport of the radioactive materials to other continents such as North America and Europe. Also of high importance is the dispersion of radioactive materials locally and within Japan. Based on the International Atomic Energy Agency (IAEA) Convention on Early Notification of a nuclear accident, several radiological data sets were collected on the accident by the Japanese authorities. Among the radioactive materials monitored, are I-131 and Cs-137 which form the major contributions to the contamination of drinking water. The radiation dose in the atmosphere was also measured. It is impractical to measure contamination and radiation dose in every place of interest. Therefore, modeling helps to predict contamination and radiation dose. Some modeling studies that have been reported in the literature include the simulation of transport and deposition of I-131 and Cs-137 from the accident, Cs-137 deposition and contamination of Japanese soils, and preliminary estimates of I-131 and Cs-137 discharged from the plant into the atmosphere. In this paper, we present statistical analytics of I-131 and Cs-137 with the goal of predicting gamma dose from the Fukushima Daiichi nuclear accident. The data sets used in our study were collected from the IAEA Fukushima Monitoring Database. As part of this study, we investigated several regression models to find the best algorithm for modeling the gamma dose. The modeling techniques used in our study include linear regression, principal component regression (PCR), partial least square (PLS) regression, and ridge regression. Our preliminary results on the first set of data showed that the linear regression model with one variable was the best with a root mean square error of 0.0133 μSv/h, compared

Industrial accidents triggered by lightning.

Science.gov (United States)

Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

2010-12-15

Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

Consequence Analysis of Release from KN-18 Cask during a Severe Transportation Accident

International Nuclear Information System (INIS)

Lim, Heoksoon; Bhang, Giin; Na, Janghwan; Ban, Jaeha; Kim, Myungsu

2015-01-01

Korea Hydro and Nuclear Power (KHNP) has launched a project entitled 'Development of APR1400 Physical Protection System Design' and conducting a new conceptual physical protection system(PPS) design. One of mayor contents is consequence analysis for spent nuclear fuel cask. Proper design of physical protection system for facilities and storage and transformation involving nuclear and radioactive material requires the quantification of potential consequence from prescribed sabotage and theft scenarios in order to properly understand the level of PPS needed for specific facilities and materials. An important aspect of the regulation of the nuclear industry is assessing the risk to the public and the environment from a release of radioactive material produced by accidental or intentional scenarios. This paper describes the consequence analysis methodology, structural analysis for KN-18 cask and results of release from the cask during a severe transportation accident. Accident during spent fuel cask transportation was numerically calculated for KN-18, and showed the integrity of the fuel assemblies and cask itself was unharmed on a scenario that is comparable to state of art NRC research. Even assumption of leakage as a size of 1 x 10''2 mm''2 does not exceed for a certain criteria at any distance

Consequence Analysis of Release from KN-18 Cask during a Severe Transportation Accident

Energy Technology Data Exchange (ETDEWEB)

Lim, Heoksoon; Bhang, Giin; Na, Janghwan; Ban, Jaeha; Kim, Myungsu [KAERI, Daejeon (Korea, Republic of)

2015-05-15

Korea Hydro and Nuclear Power (KHNP) has launched a project entitled 'Development of APR1400 Physical Protection System Design' and conducting a new conceptual physical protection system(PPS) design. One of mayor contents is consequence analysis for spent nuclear fuel cask. Proper design of physical protection system for facilities and storage and transformation involving nuclear and radioactive material requires the quantification of potential consequence from prescribed sabotage and theft scenarios in order to properly understand the level of PPS needed for specific facilities and materials. An important aspect of the regulation of the nuclear industry is assessing the risk to the public and the environment from a release of radioactive material produced by accidental or intentional scenarios. This paper describes the consequence analysis methodology, structural analysis for KN-18 cask and results of release from the cask during a severe transportation accident. Accident during spent fuel cask transportation was numerically calculated for KN-18, and showed the integrity of the fuel assemblies and cask itself was unharmed on a scenario that is comparable to state of art NRC research. Even assumption of leakage as a size of 1 x 10''2 mm''2 does not exceed for a certain criteria at any distance.

Nutritional variables and work-related accidents: a case-control study.

Science.gov (United States)

de Medeiros, M A T; Zangirolani, Lia Thieme Oikawa; Cordeiro, Ricardo Carlos; da Costa, Proença Rossana Pacheco; Diez-Garcia, Rosa Wanda

2014-01-01

Nutritional aspects are important for the prevention of diseases and disorders, and few studies have focused on the relationship between risk of work injury and nutritional variables. This study aimed to verify whether nutritional variables constitute risk factors for work-related accidents. 1,422 industrial workers (600 cases plus 822 controls). A case-control study was carried out in an industrial city in south-east Brazil. A multiple logistic regression model was adjusted using work-related accidents as the response variable and nutritional variables as predictors. The associations were assessed by Odds Ratio (OR), with a p-value work-related accidents were (a) attending formal education for an above average number of years (OR=0.91, pwork-related accidents. This indicates the need, during the formulation of policies for these kinds of government benefits, to include nutrition aspects in order to minimize work-related accidents risks.

Fuel behavior and fission product release under HTGR accident conditions

International Nuclear Information System (INIS)

Fukuda, K.; Hayashi, K.; Shiba, K.

1990-01-01

In early 1989 a final decision was made over construction of a 30 MWth HTGR called the High Temperature Engineering Test Reactor, HTTR, in Japan in order to utilize it for high temperature gas engineering tests and various nuclear material tests. The HTTR fuel is a pin-in-block type fuel element which is composed of a hexagonal graphite block with dimension of 580 mm in length and 360 mm in face-to-face distance and about 30 of the fuel rods inserted into the coolant channels drilled in the block. The TRISO coated fuel particles for HTTR are incorporated with graphite powder and phenol resin into the fuel compacts, 19 of which are encased into a graphite sleeve as a fuel rod. It is necessary for the HTTR licensing to prove the fuel stability under predicted accidents related to the high temperature events. Therefore, the release of the fission products and the fuel failure have been investigated in the irradiation---and the heating experiments simulating these conditions at JAERI. This report describes the HTTR fuel behavior at extreme temperature, made clear in these experiments

Relative evaluation on decommissioning accident scenarios of nuclear facilities

International Nuclear Information System (INIS)

Jeong, Kwan-Seong; Choi, Byung-Seon; Moon, Jei-Kwon; Hyun, Dong-Jun; Kim, Geun-Ho; Kim, Tae-Hyoung; Jo, Kyung-Hwa; Seo, Jae-Seok; Jeong, Seong-Young; Lee, Jung-Jun

2012-01-01

Highlights: ► This paper suggests relative importance on accident scenarios during decommissioning of nuclear facilities. ► The importance of scenarios can be performed by using AHP and Sugeno fuzzy method. ► The AHP and Sugeno fuzzy method guarantee reliability of the importance evaluation. -- Abstract: This paper suggests the evaluation method of relative importance on accident scenarios during decommissioning of nuclear facilities. The evaluation method consists of AHP method and Sugeno fuzzy integral method. This method will guarantee the reliability of relative importance evaluation for decommissioning accident scenarios.

The covariance between the number of accidents and the number of victims in multivariate analysis of accident related outcomes

NARCIS (Netherlands)

Bijleveld, F. D.

In this study some statistical issues involved in the simultaneous analysis of accident related outcomes of the road traffic process are investigated. Since accident related outcomes like the number of victims, fatalities or accidents show interdependencies, their simultaneous analysis requires that

Radionuclide Release after LBLOCA with Loss of Class IV Power Accident in CANDU-6 Plant

Energy Technology Data Exchange (ETDEWEB)

Choi, Hoon [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2011-10-15

A large break in a pipe train of a primary heat transport system discharges coolant, which has high energy and large mass, into the containment building. Reactor shutdown and emergency core cooling water will limit the fuel cladding failure, but cannot prevent it entirely. The containment building is the last barrier of radionuclide release to the environment. Containment isolation and pressure suppression by dousing and local air cooler reduce the amount of radionuclide release to the environment. The objective of containment behavior analysis for large break loss of coolant with loss of class IV power accident is to assess the amount of radionuclide release to the ambient atmosphere. Radionuclide release rates in this event, with all safety system available, that is, the containment building is intact, as well as with containment system impairment, are analyzed with GOTHIC and SMART code

Off-road truck-related accidents in U.S. mines.

Science.gov (United States)

Dindarloo, Saeid R; Pollard, Jonisha P; Siami-Irdemoosa, Elnaz

2016-09-01

Off-road trucks are one of the major sources of equipment-related accidents in the U.S. mining industries. A systematic analysis of all off-road truck-related accidents, injuries, and illnesses, which are reported and published by the Mine Safety and Health Administration (MSHA), is expected to provide practical insights for identifying the accident patterns and trends in the available raw database. Therefore, appropriate safety management measures can be administered and implemented based on these accident patterns/trends. A hybrid clustering-classification methodology using K-means clustering and gene expression programming (GEP) is proposed for the analysis of severe and non-severe off-road truck-related injuries at U.S. mines. Using the GEP sub-model, a small subset of the 36 recorded attributes was found to be correlated to the severity level. Given the set of specified attributes, the clustering sub-model was able to cluster the accident records into 5 distinct groups. For instance, the first cluster contained accidents related to minerals processing mills and coal preparation plants (91%). More than two-thirds of the victims in this cluster had less than 5years of job experience. This cluster was associated with the highest percentage of severe injuries (22 severe accidents, 3.4%). Almost 50% of all accidents in this cluster occurred at stone operations. Similarly, the other four clusters were characterized to highlight important patterns that can be used to determine areas of focus for safety initiatives. The identified clusters of accidents may play a vital role in the prevention of severe injuries in mining. Further research into the cluster attributes and identified patterns will be necessary to determine how these factors can be mitigated to reduce the risk of severe injuries. Analyzing injury data using data mining techniques provides some insight into attributes that are associated with high accuracies for predicting injury severity. Copyright © 2016

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.)

Learning lessons from Natech accidents - the eNATECH accident database

Science.gov (United States)

Krausmann, Elisabeth; Girgin, Serkan

2016-04-01

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

Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

International Nuclear Information System (INIS)

Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

2012-01-01

Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

Character and consequence of nuclear criticality accident

International Nuclear Information System (INIS)

Liu Xinhua; Liu Hua; Wu Deqiang; Li Bing

2001-01-01

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

[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.

Psychical and social effects related to post-accident situations: some training of Chernobyl accident

International Nuclear Information System (INIS)

Lochand, J.

1995-01-01

Some preliminary considerations on the psychic and societal dimensions related to post-accident situations connected to large scale and heavy land contamination are presented. This is done with the objective of exploring the role that these dimensions could play in the elaboration of new radiological protection principles and concepts in order to restore confidence among affected populations after a nuclear accident. It is important to facilitate the return to normal or, at least, acceptable living conditions, as soon as reasonably achievable, and to prevent the possible emergence of a post-accident crisis. A scheme is proposed for understanding the dynamics of the various phases after an accident, taking into account the collective response to the consequences as well as, the response to the countermeasures. (Author)

Methodology to classify accident sequences of an Individual Plant Examination according to the severe releases for BWR type reactors

International Nuclear Information System (INIS)

Sandoval V, S.

2001-01-01

The Light Water Reactor (LWR) operation regulations require to every operating plant to perform of an Individual Plant Examination study (Ipe). One of the main purposes of an Ipe is t o gain a more quantitative understanding of the overall probabilities of core damage and fission product releases . Probabilistic Safety Analysis (PSA) methodologies and Severe Accident Analysis are used to perform Ipe studies. PSA methodologies are used to identify and analyse the set of event sequences that might originate the fission product release from a nuclear power plant; these methodologies are combinatorial in nature and generate thousands of sequences. Among other uses within an Ipe, severe accident simulations are used to determine the characteristics of the fission product release for the identified sequences and in this way, the releases can be understood and characterized. A vast amount of resources is required to simulate and analyse every Ipe sequence. This effort is unnecessary if similar sequences are grouped. The grouping scheme must achieve an efficient trade off between problem reduction and accuracy. The methodology presented in this work enables an accurate characterization and analysis of the Ipe fission product releases by using a reduced problem. The methodology encourages the use of specific plant simulations. (Author)

Estimating the Influence of Accident Related Factors on Motorcycle Fatal Accidents using Logistic Regression (Case Study: Denpasar-Bali

Directory of Open Access Journals (Sweden)

Wedagama D.M.P.

2010-01-01

Full Text Available In Denpasar the capital of Bali Province, motorcycle accident contributes to about 80% of total road accidents. Out of those motorcycle accidents, 32% are fatal accidents. This study investigates the influence of accident related factors on motorcycle fatal accidents in the city of Denpasar during period 2006-2008 using a logistic regression model. The study found that the fatality of collision with pedestrians and right angle accidents were respectively about 0.44 and 0.40 times lower than collision with other vehicles and accidents due to other factors. In contrast, the odds that a motorcycle accident will be fatal due to collision with heavy and light vehicles were 1.67 times more likely than with other motorcycles. Collision with pedestrians, right angle accidents, and heavy and light vehicles were respectively accounted for 31%, 29%, and 63% of motorcycle fatal accidents.

Statistical evaluation of design-error related nuclear reactor accidents

International Nuclear Information System (INIS)

Ott, K.O.; Marchaterre, J.F.

1981-01-01

In this paper, general methodology for the statistical evaluation of design-error related accidents is proposed that can be applied to a variety of systems that evolves during the development of large-scale technologies. The evaluation aims at an estimate of the combined ''residual'' frequency of yet unknown types of accidents ''lurking'' in a certain technological system. A special categorization in incidents and accidents is introduced to define the events that should be jointly analyzed. The resulting formalism is applied to the development of U.S. nuclear power reactor technology, considering serious accidents (category 2 events) that involved, in the accident progression, a particular design inadequacy. 9 refs

Monitoring and surveillance in accident situations

International Nuclear Information System (INIS)

Chadwick, K.; Menzel, H.

1993-01-01

The Chernobyl accident, which occurred on 26 April 1986, presented major challenges to the European Community with respect to the practical and regulatory aspects of radiation protection, public information, trade -particularly in food - and international politics. The Chernobyl accident was also a major challenge to the international scientific community which had to evaluate rapidly the radiological consequences of the accident and advise on the introduction at Chernobyl, countermeasures to reduce the consequences of radioactive contamination had been conceived largely in the context of relatively small accidental releases and for application over relatively small areas. Less consideration had been given to the practical implications of applying such measures in the case of a large source and a spread over a very large area

Seminar on Comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents: Kyshtym, Windscale, Chernobyl. Vol. 1

International Nuclear Information System (INIS)

1991-01-01

These proceedings of seminar on comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents (Kyshtym, Windscale, Chernobyl) are divided into 5 parts bearing on: part 1: accident source terms; part 2: atmospheric dispersion, resuspension, chemical and physical forms of contamination; part 3: environmental contamination and transfer; part 4: radiological implications for man and his environment; part 5: countermeasures

Bicycling-related accidents and factors contributing to injury

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Perez, L.M.; Wideberg, J.; Gonzalez Perez-Somarriba, B.

2016-07-01

Objective: This study was conducted to find the epidemiological characteristics of bicycling-related maxillofacial fractures in a defined population, and identify factors contributing to injury. Methodology: A prospective study was carried out involving patients presenting with maxillofacial fractures sustained in bicycling-related accidents. Results: Between 908 of all cycling accidents attending for medical treatment, 122 patients (13% of all cycling accidents) were admitted with facial fractures between 2007 and 2014. Male and female ratio was 2.6:1, and the mean age was 29.4 years (standard deviation: 12.8, range: 12-79 years). Causes of injury included collisions (63%) and accidental falls (37%). The fracture patterns seen were mandibular (49%), zygomatic (32%), orbital (13%), nasal (7%), maxillary (2%), and frontal (2%). Condylar fractures were the most common of the mandibular fractures (63%). The most frequently observed concomitant lesions were orthopedic injuries. Conclusions: Bicycling-related maxillofacial injuries are common and therefore important to identify in order to design a sustainable transport system and for units that provide assistance to traffic accident victims. Missed diagnosis or delayed treatment can lead to facial deformities and functional problems. Wearing protective helmets and the improvement of the helmets design is one aspect that would be of interest for the prevention of injuries. Keywords: Cycling; bicycle-related trauma; maxillofacial fractures; risk factors; helmets. (Author)

Urban violence is the biggest cause of fatal work-related accidents in Brazil.

Science.gov (United States)

Cordeiro, Ricardo; Luz, Verônica Gronau; Hennington, Élida Azevedo; Martins, Ana Cláudia Alves; Tófoli, Luís Fernando

2017-12-11

To quantify the occurrence of deaths directly associated with urban violence among fatal work-related accidents. Verbal autopsies were performed with the relatives and coworkers of residents of Campinas, state of São Paulo, Brazil, who died from external causes in 2015. We have also analyzed police reports and reports of the Legal Medical Institute related to these deaths. We have identified 82 fatal work-related accidents in Campinas in 2015, of which 25 were murders, 35 were traffic accidents not directly related to work activities, and three were suicides at work. The proportional mortality rate for homicides, traffic accidents, and suicides among fatal work-related accidents was estimated at 30.5%, 42.7%, and 3.7%, respectively. Urban violence accounted for three-fourths of the fatal work-related accidents recorded in the period studied.

Consideration of severe accidents in design of advanced WWER reactors

International Nuclear Information System (INIS)

Fedorov, V.G.; Rogov, M.F.; Podshibyakin, A.K.; Fil, N.S.; Volkov, B.E.; Semishkin, V.P.

1998-01-01

Severe accident related requirements formulated in General Regulations for Nuclear Power Plant Safety (OPB-88), in Nuclear Safety Regulations for Nuclear Power Stations' Reactor Plants (PBYa RU AS-89) and in other NPP nuclear and radiation guides of the Russian Gosatomnadzor are analyzed. In accordance with these guides analyses of beyond design basis accidents should be performed in the reactor plant design. Categorization of beyond design basis accidents leading to severe accidents should be made on occurrence probability and severity of consequences. Engineered features and measures intended for severe accident management should be provided in reactor plant design. Requirements for severe accident analyses and for development of measures for severe accident management are determined. Design philosophy and proposed engineered measures for mitigation of severe accidents and decrease of radiation releases are demonstrated using examples of large, WWER-1000 (V-392), and medium size WWER-640 (V-407) reactor plant designs. Mitigation of severe accidents and decrease of radiation releases are supposed to be conducted on basis of consistent realization of the defense in depth concept relating to application of a system of barriers on the path of spreading of ionizing radiation and radioactive materials to the environment and a set of engineered measures protecting these barriers and retaining their effectiveness. Status of fulfilled by OKB Gidropress and other Russian organizations experimental and analytical investigations of severe accident phenomena supporting design decisions and severe accident management procedures is described. Status of the works on retention of core melt inside the WWER-640 reactor vessel is also characterized

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

International Nuclear Information System (INIS)

Aguiar, Andre Silva de

2015-01-01

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

Tritium loading in ITER plasma-facing surfaces and its release under accident conditions

International Nuclear Information System (INIS)

Longhurst, G.R.; Anderl, R.A.; Pawelko, R.J.

1996-01-01

Plasma-facing surfaces of the International Thermonuclear Experimental Reactor (ITER) will take up tritium from the plasma. These surfaces will probably consist of matures of Be, C, and possibly W together with other impurities. Recent experimental results have suggested mechanisms, not previously considered in analyses, by which tritium and other hydrogen isotopes are retained in Be. This warrants revised modeling and estimation of the amount of tritium that will be deposited in ITER beryllium plasma-facing surfaces and the rates at which it can be released under postulated accident scenarios. In this paper we describe improvements in modeling and experiments planned at the Idaho National Engineering Laboratory (INEL) to investigate the tritium uptake and thermal release behavior for mixed plasma- facing materials. TMAP4 calculations were made using recent data to estimate first-wall tritium inventories in ITER. 16 refs., 1 fig

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)

Critical analysis of accident scenario and consequences modelling applied to light-water reactor power plants for accident categories beyond the design basis accident (DBA)

International Nuclear Information System (INIS)

Brofferio, C.; Cagnetti, P.; Ferrara, V.; Manilia, E.; Pietrangeli, G.; Sennis, C.

1985-01-01

A critical analysis and sensitivity study of the modelling of accident scenarios and environmental consequences are presented, for light-water reactor accident categories beyond the standard design-basis-accident category. The first chapter, on ''source term'' deals with the release of fission products from a damaged core inventory and their migration within the primary circuit and the reactor containment. Particular attention is given to the influence of engineering safeguards intervention and of the chemical forms of the released fission products. The second chapter deals with their release to the atmosphere, transport and wet or dry deposition, outlining relevant partial effects and confronting short-duration or prolonged releases. The third chapter presents a variability analysis, for environmental contamination levels, for two extreme hypothetical scenarios, evidencing the importance of plume rise. A numerical plume rise model is outlined

Release of radionuclides following severe accident in interim storage facility. Source term determination

International Nuclear Information System (INIS)

Morandi, S.; Mariani, M.; Giacobbo, F.; Covini, R.

2006-01-01

Among the severe accidents that can cause the release of radionuclides from an interim storage facility, with a consequent relevant radiological impact on the population, there is the impact of an aircraft on the facility. In this work, a safety assessment analysis for the case of an aircraft crash into an interim storage facility is tackled. To this aim a methodology, based upon DOE, IAEA and NUREG standard procedures and upon conservative yet realistic hypothesis, has been developed in order to evaluate the total radioactivity, source term, released to the biosphere in consequence of the impact, without recurring to the use of complicated numerical codes. The procedure consists in the identification of the accidental scenarios, in the evaluation of the consequent damage to the building structures and to the waste packages and in the determination of the total release of radionuclides through the building-atmosphere interface. The methodology here developed has been applied to the case of an aircraft crash into an interim storage facility currently under design. Results show that in case of perforation followed by a fire incident the total released activity would be greater of some orders of magnitude with respect to the case of mere perforation. (author)

Major workplace related accidents in Singapore: A major trauma centre's experience.

Science.gov (United States)

Ng, Zhi Xu; Teo, Li Tserng; Go, Karen T S; Yeo, Yen Teng; Chiu, Ming Terk

2010-12-01

Major workplace related accidents pose a significant healthcare resource challenge in Singapore. Our study looks at the epidemiology of patients who were admitted for workplace related accidents, in a single institution, with an Injury Severity Score of >9. There were 196 cases of major workplace related accidents admitted between January 2006 and December 2007. The median age of patients admitted was 37 years with a large percentage being males (95.4%) and non-residents (57.1%). The most common ethnic group was Chinese (53.1%) followed by Indians (23.5%). The most common mechanism of injury was fall from height (66.3%) followed by injuries as a result of falling objects at work (21.9%). The percentage of patients who required surgical intervention was 69.9%. Patients admitted for major workplace related accidents had a median length of stay of 5 days in the hospital, a median length of 24 days of medical leave (ML), certifying them unfit for duty and the average cost of stay for each patient was S$11,000. We have a better understanding of the epidemiology and socio-economic impact of workplace related accidents through this study. Workplace related accidents result in significant number of man-days lost from work and monetary cost to employers, medical insurance and the hospital. With an improved understanding, we propose methods to prevent and reduce such accidents in future. A direct consequence of which will be the possible reduction of hospitalisation costs and better allocation of healthcare resources in the future.

49 CFR 831.13 - Flow and dissemination of accident or incident information.

Science.gov (United States)

2010-10-01

... dissemination of accident or incident information. (a) Release of information during the field investigation... 49 Transportation 7 2010-10-01 2010-10-01 false Flow and dissemination of accident or incident information. 831.13 Section 831.13 Transportation Other Regulations Relating to Transportation (Continued...

Insights into the control of the release of iodine, cesium, strontium and other fission products in the containment by severe accident management

International Nuclear Information System (INIS)

2000-03-01

This document is intended to provide a management-level overview of the technical bases for accident management activities to attenuate releases of radioactive materials in the very unlikely event of a severe nuclear power reactor accident - activities known commonly as management of severe accident source terms. Such activities are natural complements to accident management activities directed at arresting or slowing accident progression. Abbreviated, qualitative discussions are presented in the document on the more important severe nuclear reactor accidents, the nature of radioactive material releases during accidents, natural processes that act to attenuate the amount of radioactive material that can escape a power plant, and the physical and chemical principles used in engineered systems to further attenuate radioactive releases during accidents. At the end of each section of the report, an annotated bibliography is provided. These bibliographies are intended to serve as introductions to the vast literature pertinent to all aspects of accident management including the management of radioactive source terms. Finally, it must be noted that much of the presentation has been made from the perspective of conventional pressurized water reactors and boiling water reactors. Many important details will be different for other types of reactors or for reactors with special features. Readers are asked to do the mental manipulations necessary to apply the ideas discussed here to the particular circumstances and features of their own reactors. The report is based on the following outline: - a brief discussion of fission product sources; fission product characteristics; chemical compounds; - transport and deposition of fission products; brief description of different deposition and agglomeration processes; - retention of fission products; re-evaporation, resuspension, etc.; - discussion of various possibilities to enhance the removal of fission products from the containment

Management of severe accidents

International Nuclear Information System (INIS)

Jankowski, M.W.

1987-01-01

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

Management of severe accidents

International Nuclear Information System (INIS)

Jankowski, M.W.

1988-01-01

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

Evaluation of release amount of radioactivity from Chernobyl accident and of resulting radiological consequence in China

International Nuclear Information System (INIS)

Zhang Yongxing

1987-01-01

Three kinds of methods are used to evaluate the release amount from Chernoby1 RBMK-1000 reactor accident, i.e. (1) estimation by comparison with Windscale accident; (2) estimation in terms of the stock in the core; and (3) estimation according to the available monitoring data form adjacent countries such as Poland and Finland. The results obtained are as follows: the release of I-131 was 0.1-1.5 EBq, which is approximately 4-50% of the stock in the core; the release amount of Ru-103 was comparable to that of Cs-137, both approximately 5-10% of that of I-131; the volatile nuclides such as Mo-99, Ru-103, Te-132, Cs-137 etc., were in the order of 0.4 EBq; involatile nuclides were 0.2 EBq; noble gases and other fission products 10 EBq; and the total amount released was about 20 EBq, which taken together 8% of the stock in the core. The radioactive cloud cluster passed through over the area of China in the beginning of May. It was estimated that the total amount of I-131 in air over China area was about 1.6 PB q , Cs-137 about 0.3 PB q , Ru-103 about 0.2 PB q ; the total fallout in the area of China was about 3 PB q for I-131, about 0.1 PB q for Cs-137, about 0.3 PB q for Ru-103. The resulting effective dose equavalent commitment to critical group individual was about 60 μSv, collective effective dose equavalent commitment received by the population of China was about 1 x 10 4 man.Sv

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

International Nuclear Information System (INIS)

Yamaguchi, Yasuhiro; Minami, Kentaro

1991-01-01

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

Containment response and radiological release for a TMLB' accident sequence in a large dry containment

International Nuclear Information System (INIS)

Gasser, R.D.; Bieniarz, P.P.; Tills, J.L.

1987-01-01

An analysis has been performed for the Bellefonte Pressurized Water Reactor (PWR) Unit 1 to determine the containment loading and the radiological releases into the environment from a station blackout accident. A number of issues have been addressed in this analysis, which include the effects of direct heating on containment loading and the effects of fission product heating and natural convection on releases from the primary system. The results indicate that direct heating, which involves more than about 50% of the core, may fail the Bellefonte containment, but natural convection in the Reactor Coolant System (RCS) may lead to overheating and failure of the primary system piping before core slump, thus, eliminating or mitigating direct heating. Releases from the primary system are significantly increased before vessel breach, due to natural circulation, and after vessel breach, due to reevolution of retained fission products by fission product heating of RCS structures. (orig.)

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

International Nuclear Information System (INIS)

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

1980-05-01

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

Accidents - Chernobyl accident

International Nuclear Information System (INIS)

2004-01-01

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

WASTE-ACC: A computer model for analysis of waste management accidents

International Nuclear Information System (INIS)

Nabelssi, B.K.; Folga, S.; Kohout, E.J.; Mueller, C.J.; Roglans-Ribas, J.

1996-12-01

In support of the U.S. Department of Energy's (DOE's) Waste Management Programmatic Environmental Impact Statement, Argonne National Laboratory has developed WASTE-ACC, a computational framework and integrated PC-based database system, to assess atmospheric releases from facility accidents. WASTE-ACC facilitates the many calculations for the accident analyses necessitated by the numerous combinations of waste types, waste management process technologies, facility locations, and site consolidation strategies in the waste management alternatives across the DOE complex. WASTE-ACC is a comprehensive tool that can effectively test future DOE waste management alternatives and assumptions. The computational framework can access several relational databases to calculate atmospheric releases. The databases contain throughput volumes, waste profiles, treatment process parameters, and accident data such as frequencies of initiators, conditional probabilities of subsequent events, and source term release parameters of the various waste forms under accident stresses. This report describes the computational framework and supporting databases used to conduct accident analyses and to develop source terms to assess potential health impacts that may affect on-site workers and off-site members of the public under various DOE waste management alternatives

Terrorism-related injuries versus road traffic accident-related trauma: 5 years of experience in Israel.

Science.gov (United States)

Peleg, Kobi; Savitsky, Bella

2009-12-01

Terrorism victims comprise the minority among trauma injured people, but this small population imposes a burden on the health care system. Thirty percent of the population injured in terrorist activities experienced severe trauma (injury severity score > or =16), more than half of them need a surgical procedure, and 25% of the population affected by terrorism had been admitted to intensive care. Furthermore, compared with patients with non-terrorism-related trauma, victims of terrorism often arrive in bulk, as part of a mass casualty event. This poses a sudden load on hospital resources and requires special organization and preparedness. The present study compared terrorism-related and road accident-related injuries and examined clinical characteristics of both groups of patients. This study is a retrospective study of all patients injured through terrorist acts and road traffic accidents from September 29, 2000 to December 31, 2005, and recorded in the Israel Trauma Registry. Data on the nature of injuries, treatment, and outcome were obtained from the registry. Medical diagnoses were extracted from the registry and classified based on International Classification of Diseases coding. Diagnoses were grouped to body regions, based on the Barell Injury Diagnosis Matrix. The study includes 2197 patients with terrorism-related injuries and 30,176 patients injured in road traffic accidents. All in all, 27% of terrorism-related casualties suffered severe to critical injuries, comparing to 17% among road traffic accident-related victims. Glasgow Coma Scale scores terrorism victims, in contrast with 7.4% among people injured on the roads. The terrorism victims had a significantly higher rate of use of intensive care facilities (24.2% vs 12.4%). The overall inpatient death rate was 6.0% among terrorism victims and 2.4% among those injured in road traffic accidents. Casualties from terrorist events are more severely injured and require more resources relative to casualties

Massive radiological releases profoundly differ from controlled releases

International Nuclear Information System (INIS)

Pascucci-Cahen, Ludivine; Patrick, Momal

2012-11-01

Preparing for a nuclear accident implies understanding potential consequences. While many specialized experts have been working on different particular aspects, surprisingly little effort has been dedicated to establishing the big picture and providing a global and balanced image of all major consequences. IRSN has been working on the cost of nuclear accidents, an exercise which must strive to be as comprehensive as possible since any omission obviously underestimates the cost. It therefore provides (ideally) an estimate of all cost components, thus revealing the structure of accident costs, and hence sketching a global picture. On a French PWR, it appears that controlled releases would cause an 'economical' accident with limited radiological consequences when compared to other costs; in contrast, massive releases would trigger a major crisis with strong radiological consequences. The two types of crises would confront managers with different types of challenges. (authors)

Atmospheric releases from severe nuclear accidents: Environmental transport and pathways to man: Modelling of radiation doses to man from Chernobyl releases

International Nuclear Information System (INIS)

Anspaugh, L.R.; Goldman, M.; Catlin, R.J.

1987-01-01

The Chernobyl accident released a large amount of highly fractionated radioactive debris, including approximately 89 PBq of 137 Cs. We calculated the resulting collective dose commitment to the Northern Hemisphere via the pathways of external exposure and ingestion of radionuclides withd food. We developed a rural/urban model of external dose and we used the PATHWAY model for ingestion. The results are a collective dose commitment of 630,000 person-Gy over the first year and 1,200,000 person-Gy over 50 years. 13 refs., 1 tab

Sensitivity analysis for CORSOR models simulating fission product release in LOFT-LP-FP-2 severe accident experiment

Energy Technology Data Exchange (ETDEWEB)

Hoseyni, Seyed Mohsen [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Basic Sciences; Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Young Researchers and Elite Club; Pourgol-Mohammad, Mohammad [Sahand Univ. of Technology, Tabriz (Iran, Islamic Republic of). Dept. of Mechanical Engineering; Yousefpour, Faramarz [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

2017-03-15

This paper deals with simulation, sensitivity and uncertainty analysis of LP-FP-2 experiment of LOFT test facility. The test facility simulates the major components and system response of a pressurized water reactor during a LOCA. MELCOR code is used for predicting the fission product release from the core fuel elements in LOFT LP-FP-2 experiment. Moreover, sensitivity and uncertainty analysis is performed for different CORSOR models simulating release of fission products in severe accident calculations for nuclear power plants. The calculated values for the fission product release are compared under different modeling options to the experimental data available from the experiment. In conclusion, the performance of 8 CORSOR modeling options is assessed for available modeling alternatives in the code structure.

Reactor accidents. Chernobyl and Three Miles Island

International Nuclear Information System (INIS)

Marx, G.

1990-01-01

A description of the facilities at Chernobyl and TMI, as well as of the course of the accidents is given. Supplementary information relates to the quantities and types of radionuclides released and to the size of the group of persons concerned. (DG) [de

Interaction of radionuclides in severe accident conditions

International Nuclear Information System (INIS)

Nagrale, Dhanesh B.; Bera, Subrata; Deo, Anuj Kumar; Paul, U.K.; Prasad, M.; Gaikwad, A.J.

2015-01-01

Nuclear power plants are designed with inherent engineering safety systems and associated operational procedures that provide an in-depth defence against accidents. Radionuclides such as Iodine, Cesium, Tellurium, Barium, Strontium, Rubidium, Molybdenum and many others may get released during a severe accident. Among these, Iodine, one of the fission products, behaviour is significant for the analysis of severe accident consequences because iodine is a chemically more active to the potential components released to the environment. During severe accident, Iodine is released and transported in aqueous, organic and inorganic forms. Iodine release from fuel, iodine transport in primary coolant system, containment, and reaction with control rods are some of the important phases in a severe accident scenario. The behaviour of iodine is governed by aerosol physics, depletion mechanisms gravitational settling, diffusiophoresis and thermophoresis. The presence of gaseous organic compounds and oxidizing compounds on iodine, reactions of aerosol iodine with boron and formation of cesium iodide which results in more volatile iodine release in containment play significant roles. Water radiolysis products due to presence of dissolved impurities, chloride ions, organic impurities should be considered while calculating iodine release. Containment filtered venting system (CFVS) consists of venturi scrubber and a scrubber tank which is dosed with NaOH and NaS_2O_3 in water where iodine will react with the chemicals and convert into NaI and Na_2SO_4. This paper elaborates the issues with respect to interaction of radionuclides and its consideration in modeling of severe accident. (author)

Consequences of severe radioactive releases to Nordic Marine environment

Energy Technology Data Exchange (ETDEWEB)

Iosjpe, M. [Norwegian Radiation Protection Authority (NRPA) (Norway); Isaksson, M. [Univ. of Gothenburg (Sweden); Joensen, H.P. [Froskaparsetur Foeroya. Faroe Islands, Torshavn (Denmark); Lahtinen, J. [Radiation and Nuclear Safety Authority (Finland); Logemann, K. [Univ. of Iceland (Iceland); Palsson, S.E. [Geislavarnir Rikisins (Iceland); Roos, P. [Technical Univ. of Denmark. Risoe DTU, Roskilde (Denmark); Suolanen, V. [Technical Research Centre of Finland (Finland)

2013-02-15

In the report, consequences of hypothetical severe nuclear accidents releases to Nordic marine environment are preliminary considered. The considered marine area comprises the Baltic Sea (Sweden, Denmark, Finland) and the North Atlantic (Iceland, Faroes, Norway) areas. The hypothetical severe nuclear accidents can be related to nuclear power plants, nuclear powered submarines or ice-breakers. Quite comprehensive survey on radioactive source terms of extremely severe nuclear power and submarine accidents has been done. This enables to estimate more realistically possible radioactive releases of various elements and nuclides to marine environment. One recent reference is of course the Fukushima accident and estimated releases there. The marine flows and dilution circumstances around the Nordic nuclear power plants and in the Baltic Sea area in general, has been studied. Respectively marine flows related to Iceland and Faroes coasts are considered with measured data and with preliminary 3D-model simulations. The substantial depth of sea water in the North Atlantic affect vertical concentration profiles to some extent. At Icelandic or Faroese waters, a potential submarine accident would likely occur in a well defined water mass, and radioactivity from the accident would be detected and spread with the flow regime of the water mass in the world ocean. Based on hypothetical severe accidents scenarios, preliminary consequence calculations has been done. It should be emphasised that the considered severe accident cases, considered in this study, do not directly attach any specific Nordic nuclear power plant or any specific submarine type. The considered radioactive releases will, however, provide specified references for more extensive consideration of environmental consequences of severe - or minor - radioactive releases to Nordic marine environment. As a reference, the release amounts from a 3000 MW{sub th} reactor size were used. Based on source term analyses, the

Consequences of severe radioactive releases to Nordic Marine environment

International Nuclear Information System (INIS)

Iosjpe, M.; Isaksson, M.; Joensen, H.P.; Lahtinen, J.; Logemann, K.; Palsson, S.E.; Roos, P.; Suolanen, V.

2013-02-01

In the report, consequences of hypothetical severe nuclear accidents releases to Nordic marine environment are preliminary considered. The considered marine area comprises the Baltic Sea (Sweden, Denmark, Finland) and the North Atlantic (Iceland, Faroes, Norway) areas. The hypothetical severe nuclear accidents can be related to nuclear power plants, nuclear powered submarines or ice-breakers. Quite comprehensive survey on radioactive source terms of extremely severe nuclear power and submarine accidents has been done. This enables to estimate more realistically possible radioactive releases of various elements and nuclides to marine environment. One recent reference is of course the Fukushima accident and estimated releases there. The marine flows and dilution circumstances around the Nordic nuclear power plants and in the Baltic Sea area in general, has been studied. Respectively marine flows related to Iceland and Faroes coasts are considered with measured data and with preliminary 3D-model simulations. The substantial depth of sea water in the North Atlantic affect vertical concentration profiles to some extent. At Icelandic or Faroese waters, a potential submarine accident would likely occur in a well defined water mass, and radioactivity from the accident would be detected and spread with the flow regime of the water mass in the world ocean. Based on hypothetical severe accidents scenarios, preliminary consequence calculations has been done. It should be emphasised that the considered severe accident cases, considered in this study, do not directly attach any specific Nordic nuclear power plant or any specific submarine type. The considered radioactive releases will, however, provide specified references for more extensive consideration of environmental consequences of severe - or minor - radioactive releases to Nordic marine environment. As a reference, the release amounts from a 3000 MW th reactor size were used. Based on source term analyses, the chosen

Wheelchair-related accidents: relationship with wheelchair-using behavior in active community wheelchair users.

Science.gov (United States)

Chen, Wan-Yin; Jang, Yuh; Wang, Jung-Der; Huang, Wen-Ni; Chang, Chan-Chia; Mao, Hui-Fen; Wang, Yen-Ho

2011-06-01

To report the prevalence, mechanisms, self-perceived causes, consequences, and wheelchair-using behaviors associated with wheelchair-related accidents. A case-control study. Community. A sample of experienced, community-dwelling, active manual and powered wheelchair users (N=95) recruited from a hospital assistive technology service center. Not applicable. Wheelchair-using behaviors, wheelchair-related accidents over a 3-year period, and the mechanisms and consequences of the accidents. Among the 95 participants, 52 (54.7%) reported at least 1 accident and 16 (16.8%) reported 2 or more accidents during the 3 years prior to the interview. A total of 74 accidents, were categorized into tips and falls (87.8%), accidental contact (6.8%), and dangerous operations (5.4%). A logistic regression found individuals who failed to maintain their wheelchairs regularly (odds ratio [OR]=11.28; 95% confidence interval [CI], 2.62-48.61) and used a wheelchair not prescribed by professionals (OR=4.31; 95% CI, 1.10-16.82) had significantly greater risks of accidents. In addition to the risk factor, lack of regular wheelchair maintenance, the Poisson regression corroborated the other risk factor, seat belts not used (incident rate ratio=2.14; 95% CI, 1.08-4.14), for wheelchair-related accidents. Wheelchair-related accidents are closely related to their wheelchair-using behaviors. Services including professional evaluation, repair, maintenance, and an educational program on proper wheelchair use may decrease the risks of wheelchair accidents. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Evaluation of radiological releases from the Tomsk-7 accident

Energy Technology Data Exchange (ETDEWEB)

Lussie, W.G.

1995-10-01

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

Evaluation of radiological releases from the Tomsk-7 accident

International Nuclear Information System (INIS)

Lussie, W.G.

1995-01-01

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

Description of the blowdown test facility COG program on in-reactor fission product release, transport, and deposition under severe accident conditions

International Nuclear Information System (INIS)

Fehrenbach, P.J.; Wood, J.C.

1987-06-01

Loss-of-coolant accidents with additional impairment of emergency cooling would probably result in high fuel temperatures leading to severe fuel damage (SFD) and significant fission product activity would then be transported along the PHTS to the break where a fraction of it would be released and transport under such conditions, there are many interacting and sometimes competing phenomena to consider. Laboratory simulations are being used to provide data on these individual phenomena, such as UO 2 oxidation and Zr-UO 2 interaction, from which mathematical models can be constructed. These are then combined into computer codes to include the interaction effects and assess the overall releases. In addition, in-reactor tests are the only source of data on release and transport of short-lived fission product nuclides, which are important in the consequence analysis of CANDU reactor accidents. Post-test decontamination of an in-reactor test facility also provides a unique opportunity to demonstrate techniques and obtain decontamination data relevant to post-accident rehabilitation of CANDU power reactors. Specialized facilities are required for in-reactor testing because of the extensive release of radioactive fission products and the high temperatures involved (up to 2500 degrees Celsius). To meet this need for the Canadian program, the Blowdown Test Facility (BTF) has been built in the NRU reactor at Chalk River. Between completion of construction in mid-1987 and the first Zircaloy-sheathed fuel test in fiscal year 1987/88, several commissioning tests are being performed. Similarly, extensive development work has been completed to permit application of instrumentation to irradiated fuel elements, and in support of post-test fuel assembly examination. A program of decontamination studies has also been developed to generate information relevant to post-accident decontamination of power reactors. The BTF shared cost test program funded by the COG High Temperature

Analysis of release and transport of aerial radioactive materials in accident of evaporation to dryness caused by boiling of reprocessed high-level liquid waste

International Nuclear Information System (INIS)

Yoshida, Kazuo; Ishikawa, Jun; Abe, Hitoshi

2015-01-01

An accident of evaporation to dryness caused by boiling of high-level liquid waste (HLLW) is postulated as one of the severe accidents caused by the loss of cooling function at a fuel reprocessing plant. In this case, some amount of fission products (FPs) will be transferred to the vapor phase in the tank, and could be released to the environment. Therefore, the quantitative estimation of the transport and release behavior of FPs is one of the key issues in the assessment of the accident consequence. To resolve this issue, a systematic analysis method with computer codes has been developed on the basis of the phenomenological behavior in the accident of evaporation to dryness caused by boiling of HLLW. A simulation study demonstrated that the behavior of liquid waste temperature and the entrainment of mists were in good agreement with the experimental results during the early boiling stage, and that some issues to be resolved were pointed out for the estimation of the amount of transferred Ru to the vapor phase at the late boiling stage. (author)

A description of nuclear reactor accidents and their consequences

International Nuclear Information System (INIS)

Murray, A.

1989-01-01

Nuclear reactor accidents which have caused core damage, released a significant amount of radioactivity, or caused death or serious injury are described. The reactor accidents discussed in detail include Chernobyl, Three Mile Island, SL-1 and Windscale, although information on other less consequential accidents is also provided. The consequences of these accidents are examined in terms of the amounts of radioactivity released, the radiation doses received, and remedial actions and interventions taken following the accident. 10 refs., 1 fig., 2 tabs

Work-related accidents among the Iranian population: a time series analysis, 2000-2011.

Science.gov (United States)

Karimlou, Masoud; Salehi, Masoud; Imani, Mehdi; Hosseini, Agha-Fatemeh; Dehnad, Afsaneh; Vahabi, Nasim; Bakhtiyari, Mahmood

2015-01-01

Work-related accidents result in human suffering and economic losses and are considered as a major health problem worldwide, especially in the economically developing world. To introduce seasonal autoregressive moving average (ARIMA) models for time series analysis of work-related accident data for workers insured by the Iranian Social Security Organization (ISSO) between 2000 and 2011. In this retrospective study, all insured people experiencing at least one work-related accident during a 10-year period were included in the analyses. We used Box-Jenkins modeling to develop a time series model of the total number of accidents. There was an average of 1476 accidents per month (1476·05±458·77, mean±SD). The final ARIMA (p,d,q) (P,D,Q)s model for fitting to data was: ARIMA(1,1,1)×(0,1,1)12 consisting of the first ordering of the autoregressive, moving average and seasonal moving average parameters with 20·942 mean absolute percentage error (MAPE). The final model showed that time series analysis of ARIMA models was useful for forecasting the number of work-related accidents in Iran. In addition, the forecasted number of work-related accidents for 2011 explained the stability of occurrence of these accidents in recent years, indicating a need for preventive occupational health and safety policies such as safety inspection.

Safety against releases in severe accidents. Final report

International Nuclear Information System (INIS)

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

1997-12-01

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

Considerations relating to the presence of water in the reactor cavity during severe accidents

International Nuclear Information System (INIS)

Perez, F.; Morales, M.D.

1994-01-01

The purpose of this paper is to present some of the factors, both positive and negative, associated with the presence of water in the reactor cavity. The presence of water in the reactor cavity is one of the factors whose influence on the evolution of severe accidents must be determined since, on the one hand, it has an impact on some of the most significant severe accident phenomena and, on the other, it could be an important factor when preparing accident management strategies resulting from containment analyses. In spite of the initial intuitive impression that water in the reactor cavity must always be beneficial, certain phenomena, such as the following must also be taken into account before developing accident management strategies: - Higher production of steam - Possibility of steam explosions - Increased production of H 2 due to oxidation of steel components of the melted core ejected from the vessel - More oxidation energy released due to the presence of oxygen in the cavity (Author)

Insomnia and accidents: cross-sectional study (EQUINOX) on sleep-related home, work and car accidents in 5293 subjects with insomnia from 10 countries.

Science.gov (United States)

Léger, Damien; Bayon, Virginie; Ohayon, Maurice M; Philip, Pierre; Ement, Philippe; Metlaine, Arnaud; Chennaoui, Mounir; Faraut, Brice

2014-04-01

The link between sleepiness and the risk of motor vehicle accidents is well known, but little is understood regarding the risk of home, work and car accidents of subjects with insomnia. An international cross-sectional survey was conducted across 10 countries in a population of subjects with sleep disturbances. Primary care physicians administered a questionnaire that included assessment of sociodemographic characteristics, sleep disturbance and accidents (motor vehicle, work and home) related to sleep problems to each subject. Insomnia was defined using the International Classification of Sleep Disorders (ICSD-10) criteria. A total of 5293 subjects were included in the study, of whom 20.9% reported having had at least one home accident within the past 12 months, 10.1% at least one work accident, 9% reported having fallen asleep while driving at least once and 4.1% reported having had at least one car accident related to their sleepiness. All types of accident were reported more commonly by subjects living in urban compared to other residential areas. Car accidents were reported more commonly by employed subjects, whereas home injuries were reported more frequently by the unemployed. Car accidents were reported more frequently by males than by females, whereas home accidents were reported more commonly by females. Patients with insomnia have high rates of home accidents, car accidents and work accidents related to sleep disturbances independently of any adverse effects of hypnotic treatments. Reduced total sleep time may be one factor explaining the high risk of accidents in individuals who complain of insomnia. © 2013 European Sleep Research Society.

Caesium releases under the form of silicon micro-balls during the Fukushima-Daiichi accident. Information note

International Nuclear Information System (INIS)

2016-01-01

After having outlined that the most part (89 per cent) of radioactive cesium released in the atmosphere during the Fukushima accident was made under the form of silicon micro-balls which were more irradiating than other aerosols marked by cesium radioactive isotopes, this note first discusses whether these silicon micro-balls containing radioactive cesium were resulting from a specific phase of atmospheric release. It discusses the nature of these micro-balls, and discusses whether it is possible to quantitatively assess the contribution of these micro-balls to global releases and deposits. It discusses how these micro-balls could have formed, whether their formation can be associated with a specific phase of reactor degradation or with the degradation of a specific reactor. It discusses whether a specific behaviour of these micro-balls can be expected in the environment, and their possible impacts on radiological consequences

CARNSORE: Hypothetical reactor accident study

International Nuclear Information System (INIS)

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

1984-06-01

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

Detection of Pu in Pacific Ocean water with AMS related to the Fukushima accident

Energy Technology Data Exchange (ETDEWEB)

Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Guzman, Jose Manuel; Korschinek, Gunther; Kortmann, Florian; Lierse v Gostomski, Christoph; Ludwig, Peter [TUM (Germany); Golser, Robin; Steier, Peter [Universitaet Wien (Austria); Yamada, Masatoshi [Hirosaki University (Japan)

2016-07-01

The concentration of plutonium (Pu) and its isotopic ratios were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples. The isotopic ratios {sup 240}Pu/{sup 239}Pu and {sup 241}Pu/{sup 239}Pu can be used to identify a possible release of Pu into the ocean by the Fukushima accident. {sup 241}Pu from fallout of nuclear weapon testings has already significantly decayed. {sup 241}Am, the daughter nuclide of {sup 241}Pu, causes isobaric background on {sup 241}Pu in mass-spectrometric measurements. Therefore, Am and Pu had to be separated chemically using extraction chromatography. The method was verified by analyzing certified reference material. 12 sea water samples, collected at different depths, were prepared at the Radiochemie Muenchen. The concentration of Pu was measured with AMS at the Maier-Leibnitz-Laboratory in Munich and the Vienna Environmental Research Laboratory (VERA). After a short motivation related to the Fukushima accident, the chemical separation method will be presented. Preliminary results of the distribution of Pu in ocean water will be discussed.

Experiments for post accident hydrogen dispersion in F.M. vault using helium

International Nuclear Information System (INIS)

Bajaj, S.S.; Bhattacharyya, D.; Mishra, S.

1994-01-01

Under certain postulated accident scenarios involving a Loss of Coolant Accident (LOCA) simultaneous with impairment of Emergency Core Cooling (ECC), generation of hydrogen due to reaction between the zirconium clad and coolant is predicted in the coolant channel. The hydrogen generated in the coolant channels would eventually get released either in Fuelling Machine (FM) vault or in the pump room atmosphere depending on the location of the break. Analytical studies carried out so far to estimate the time dependent hydrogen concentration in the accident FM Vault consider the entire vault as a single volume. Tests were, therefore, planned to assess the mixing within the FM vault atmosphere with and without the availability of cooling fan units by releasing a known quantity of helium (instead of hydrogen) at selected locations and monitoring the relative concentration of helium in air at various locations. Test was conducted by releasing about 360 1 helium over a period of to 4 minutes at preselected locations and by measuring the relative concentration (leak rates indicated by helium leak detectors) at various locations in the FM vault. The results of cases with fans operating indicate repeatable and consistent trends of good mixing in the vault. For other cases (non turbulent, still condition) the results are sensitive to various factors including orientation of release. The former set of cases (turbulent. fans operating) are more relevant for postulated accident conditions. (author). 1 tab., 18 figs

Health-related economic costs of the Three-Mile Island accident.

Science.gov (United States)

Hu, T W; Slaysman, K S

1984-01-01

On March 1979, a nuclear power station at Three-Mile Island (TMI) near Harrisburg, Pennsylvania, had a major breakdown. During the two-week period of the accident, about 150,000 residents were evacuated for reasons associated with safety and health. Many residents during and after the accident, regardless of whether they left or stayed, made mental and physical adjustments due to this accident. This paper is to estimate the economic costs incurred by individuals or communities as a result of a change in physical or mental health status and/or a change in health care services due to the TMI accident. The findings indicate that stress symptoms caused by the accident did affect the health-related behaviors of area residents. Of the costs examined, the economic costs of work days lost and physician visits are the largest cost items. There were some increases in consumption of alcohol, cigarettes, and tranquilizers immediately following the accident.

Safety against releases in severe accidents. Final report

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-02-01

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

Fission-product releases from a PHWR terminal debris bed

Energy Technology Data Exchange (ETDEWEB)

Brown, M.J.; Bailey, D.G., E-mail: morgan.brown@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

2016-06-15

During an unmitigated severe accident in a pressurized heavy water reactor (PHWR) with horizontal fuel channels, the core may disassemble and relocate to the bottom of the calandria vessel. The resulting heterogeneous in-vessel terminal debris bed (TDB) would likely be quenched by any remaining moderator, and some of the decay heat would be conducted through the calandria vessel shell to the surrounding reactor vault or shield tank water. As the moderator boiled off, the solid debris bed would transform into a more homogeneous molten corium pool located between top and bottom crusts. Until recently, the severe accident code MAAP-CANDU assumed that unreleased volatile and semi-volatile fission products remained in the TDB until after calandria vessel failure, due to low diffusivity through the top crust and the lack of gases or steam to flush released fission products from the debris. However, national and international experimental results indicate this assumption is unlikely; instead, high- and medium-volatility fission products would be released from a molten debris pool, and their volatility and transport should be taken into account in TDB modelling. The resulting change in the distribution of fission products within the reactor and containment, and the associated decay heat, can have significant effects upon the progression of the accident and fission-product releases to the environment. This article describes a postulated PHWR severe accident progression to generate a TDB and the effects of fission-product releases from the terminal debris, using the simple release model in the MAAP-CANDU severe accident code. It also provides insights from various experimental programs related to fission-product releases from core debris, and their applicability to the MAAP-CANDU TDB model. (author)

Work-related versus non-work-related road accidents, developments in the last decade in France.

Science.gov (United States)

Charbotel, Barbara; Martin, Jean Louis; Chiron, Mireille

2010-03-01

The aim of this research was to analyze the changes that have affected work-related road accidents between 1997 and 2006, using police data. The study focused on drivers aged between 14 and 64 years. The characteristics considered were the age, gender, type of vehicle and occupation of the individuals involved and the location, time and severity of the accident. Two periods were compared, 1997-2000 and 2003-2006. Three types of journey were considered: while at work, commuting (going to and from work), and non-work-related. The percentage of all accidents which were work-related varied little over the decade (10% while at work and 18% while commuting). The accidents that occurred while at work still had the lowest fatality rates (1.4% among women and 3.4% among men in 2003-2006). Men accounted for the majority of the casualties: 90% of fatalities while at work and approximately 80% for the other types of journey. The greatest reduction took place in the number of motorists, and this has led to an increase in the proportion of motorized two-wheelers both while at work and while commuting. In the case of accidents while at work, the professional drivers still had the highest risk, craftsmen and shopkeepers were also at higher risk than manual workers of both genders and male employees. Extending analysis of this type to other European countries would be of major interest both for epidemiological monitoring and the prevention of occupational road accidents. Copyright 2009 Elsevier Ltd. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-06-15

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

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

International Nuclear Information System (INIS)

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

2012-06-01

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

Water reactor fuel behaviour and fission products release in off-normal and accident conditions

International Nuclear Information System (INIS)

1987-09-01

The present meeting was scheduled by the International Atomic Energy Agency upon the proposal of the Members of the International Working Group on Water Reactor Fuel Performance and Technology and held at the IAEA Headquarters in Vienna from 10 to 13 November 1986. Thirty participants from 17 countries and an international organization attended the meeting. Eighteen papers were presented from 13 countries and one international organization. The meeting was composed of four sessions and covered subjects related to: physico-chemical properties of core materials under off-normal conditions, and their interactions up to and after melt-down (5 papers); core materials deformation, relocation and core coolability under (severe) accident conditions (4 papers); fission products release: including experience, mechanisms and modelling (5 papers); power plant experience (4 papers). A separate abstract was prepared for each of these 18 papers. Four working groups covering the above-mentioned topics were held to discuss the present status of the knowledge and to develop recommendations for future activities in this field. Refs, figs and tabs

National emergency plan for nuclear accidents

International Nuclear Information System (INIS)

1992-10-01

The national emergency plan for nuclear accidents is a plan of action designed to provide a response to accidents involving the release or potential release of radioactive substances into the environment, which could give rise to radiation exposure to the public. The plan outlines the measures which are in place to assess and mitigate the effects of nuclear accidents which might pose a radiological hazard in ireland. It shows how accident management will operate, how technical information and monitoring data will be collected, how public information will be provided and what measures may be taken for the protection of the public in the short and long term. The plan can be integrated with the Department of Defence arrangements for wartime emergencies

Revised accident source terms for light-water reactors

Energy Technology Data Exchange (ETDEWEB)

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

1995-02-01

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

Review of Atomic Energy Laws Related to Radiological Accidents and Methods of Improvement

Energy Technology Data Exchange (ETDEWEB)

Chang, Gun Hyun; Kim, Sang Won; Yoo, Jeong; Ahn, Hyoung Jun; Park, Young Sik; Kim, Hong Suk; Kwon, Jeong Wan; Jang, Ki Won; Kim, Sok Chul [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2009-05-15

Atomic energy-related laws in Korea have a two pronged management system for radiological accidents. To be specific, the Atomic Energy Act is applicable to all radiological accidents, i.e. accidents pertaining to nuclear facilities and radioactive materials while the Act for Physical Protection and Radiological Emergency ('APPRE') applies to accidents related to nuclear materials and large-scale nuclear facilities. The Atomic Energy Act contains three provisions directly related with radiological accidents (Articles 89, 98 and 102). Article 89 provides for the obligations of nuclear licensees or consigned transporters to institute safety measures and file a report to the head of the Ministry of Education, Science and Technology ('MEST') in the event of any radiological accident during transport or packing of radioactive materials, etc. Article 98 stipulates obligations of nuclear licensees to implement safety procedures and submit a report to the Minister of Education, Science and Technology concerning radiation hazards arising in the event a radiological accident occurs in connection with nuclear projects, as well as the Minister's requests to implement necessary measures. Article 102 explicitly provides for obligations to file a report to the Minister in the event of theft, loss, fire or other accidents involving radioactive materials, etc. in the possession of nuclear licensees. The APPRE classifies radiological accidents according to location and scale of the accidents. Based on location, accidents are divided into accidents inside or outside nuclear facilities. Accidents inside nuclear facilities refer to accidents that occur at nuclear reactors, nuclear fuel cycling facilities, radioactive waste storage, treatment and disposal facilities, facilities using nuclear materials and facilities related to radioisotopes of not lower than 18.5PBq (Subparagraph 2, Article 2 of the APPRE) while accidents outside nuclear facilities mean accidents

Review of Atomic Energy Laws Related to Radiological Accidents and Methods of Improvement

International Nuclear Information System (INIS)

Chang, Gun Hyun; Kim, Sang Won; Yoo, Jeong; Ahn, Hyoung Jun; Park, Young Sik; Kim, Hong Suk; Kwon, Jeong Wan; Jang, Ki Won; Kim, Sok Chul

2009-01-01

Atomic energy-related laws in Korea have a two pronged management system for radiological accidents. To be specific, the Atomic Energy Act is applicable to all radiological accidents, i.e. accidents pertaining to nuclear facilities and radioactive materials while the Act for Physical Protection and Radiological Emergency ('APPRE') applies to accidents related to nuclear materials and large-scale nuclear facilities. The Atomic Energy Act contains three provisions directly related with radiological accidents (Articles 89, 98 and 102). Article 89 provides for the obligations of nuclear licensees or consigned transporters to institute safety measures and file a report to the head of the Ministry of Education, Science and Technology ('MEST') in the event of any radiological accident during transport or packing of radioactive materials, etc. Article 98 stipulates obligations of nuclear licensees to implement safety procedures and submit a report to the Minister of Education, Science and Technology concerning radiation hazards arising in the event a radiological accident occurs in connection with nuclear projects, as well as the Minister's requests to implement necessary measures. Article 102 explicitly provides for obligations to file a report to the Minister in the event of theft, loss, fire or other accidents involving radioactive materials, etc. in the possession of nuclear licensees. The APPRE classifies radiological accidents according to location and scale of the accidents. Based on location, accidents are divided into accidents inside or outside nuclear facilities. Accidents inside nuclear facilities refer to accidents that occur at nuclear reactors, nuclear fuel cycling facilities, radioactive waste storage, treatment and disposal facilities, facilities using nuclear materials and facilities related to radioisotopes of not lower than 18.5PBq (Subparagraph 2, Article 2 of the APPRE) while accidents outside nuclear facilities mean accidents that take place on

Chernobyl accident: Assessing the data

Energy Technology Data Exchange (ETDEWEB)

Soerensen, B

1986-01-01

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

Reactor accidents and the environment

International Nuclear Information System (INIS)

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

1978-01-01

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

Work-related accidents among the Iranian population: a time series analysis, 2000–2011

Science.gov (United States)

Karimlou, Masoud; Imani, Mehdi; Hosseini, Agha-Fatemeh; Dehnad, Afsaneh; Vahabi, Nasim; Bakhtiyari, Mahmood

2015-01-01

Background Work-related accidents result in human suffering and economic losses and are considered as a major health problem worldwide, especially in the economically developing world. Objectives To introduce seasonal autoregressive moving average (ARIMA) models for time series analysis of work-related accident data for workers insured by the Iranian Social Security Organization (ISSO) between 2000 and 2011. Methods In this retrospective study, all insured people experiencing at least one work-related accident during a 10-year period were included in the analyses. We used Box–Jenkins modeling to develop a time series model of the total number of accidents. Results There was an average of 1476 accidents per month (1476·05±458·77, mean±SD). The final ARIMA (p,d,q) (P,D,Q)s model for fitting to data was: ARIMA(1,1,1)×(0,1,1)12 consisting of the first ordering of the autoregressive, moving average and seasonal moving average parameters with 20·942 mean absolute percentage error (MAPE). Conclusions The final model showed that time series analysis of ARIMA models was useful for forecasting the number of work-related accidents in Iran. In addition, the forecasted number of work-related accidents for 2011 explained the stability of occurrence of these accidents in recent years, indicating a need for preventive occupational health and safety policies such as safety inspection. PMID:26119774

Airborne concentrations of radioactive materials in severe accidents

International Nuclear Information System (INIS)

Ross, D.F. Jr.; Denning, R.S.

1989-01-01

Radioactive materials would be released to the containment building of a commercial nuclear reactor during each of the stages of a severe accident. Results of analyses of two accident sequences are used to illustrate the magnitudes of these sources of radioactive materials, the resulting airborne mass concentrations, the characteristics of the airborne aerosols, the potential for vapor forms of radioactive materials, the effectiveness of engineered safety features in reducing airborne concentrations, and the release of radioactive materials to the environment. Ability to predict transport and deposition of radioactive materials is important to assessing the performance of containment safety features in severe accidents and in the development of accident management procedures to reduce the consequences of severe accidents

Chernobyl accident and Denmark

International Nuclear Information System (INIS)

1986-12-01

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

Chernobyl accident and Danmark

International Nuclear Information System (INIS)

1986-12-01

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

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

Science.gov (United States)

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

2018-03-05

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

Meteorological data related to the Chernobyl accident

International Nuclear Information System (INIS)

Graziani, G.; Zarimpas, N.

1989-01-01

This report presents a detailed technical description of the JRC-Ispra comprehensive collection of meteorological information related to the Chernobyl accident and attempts an analysis of the data in order to perform an initial checking of their quality and facilitate a suitable and compact way of display

Risk Analysis of Fukushima Accident using MACCS2

Energy Technology Data Exchange (ETDEWEB)

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

2014-05-15

It has been three years since Fukushima Daiichi accident had occurred. Many efforts have been done for a restoration, however, radioactive materials are still released resulting in a crucial additional damage to a human health and economics and the scale of damage is not much evaluated. Therefore, an estimation of damage degree caused by the released radioactive materials right after a nuclear accident is essential to cope with additional radioactive problems. Here, we report the risk analysis of Fukushima Dai-ichi accident using MELCOR Accident Consequence Code System 2 (MACCS2), which is the Nuclear Regulatory Commission's (NRC's) code for evaluating off-site consequences. It is used in level-3 Probabilistic Risk Analyses (PRA), for planning purposes, for cost-benefit analyses and so on. The purpose of this study is to estimate radiological doses and health risks of Fukushima Daiichi accident through short- and long-term of lifetime using MACCS2. In summary, the health risk for inhabitants near Fukushima Daiichi NPP has been evaluated by considering the long term radiation effect using MACCS2 code. The result indicates that the occurrence and death rate of the cancer have been increased by the radioactive materials released from Fukushima Daiichi accident. The result obtained in this study may provide new insights for taking action after the nuclear reactor accident to mitigate the released radioactive materials and to prepare the countermeasure.

Application of logical analysis of data to machinery-related accident prevention based on scarce data

International Nuclear Information System (INIS)

Jocelyn, Sabrina; Chinniah, Yuvin; Ouali, Mohamed-Salah; Yacout, Soumaya

2017-01-01

This paper deals with the application of Logical Analysis of Data (LAD) to machinery-related occupational accidents, using belt-conveyor-related accidents as an example. LAD is a pattern recognition and classification approach. It exploits the advancement in information technology and computational power in order to characterize the phenomenon under study. The application of LAD to machinery-related accident prevention is innovative. Ideally, accidents do not occur regularly, and as a result, companies have little data about them. The first objective of this paper is to demonstrate the feasibility of using LAD as an algorithm to characterize a small sample of machinery-related accidents with an adequate average classification accuracy. The second is to show that LAD can be used for prevention of machinery-related accidents. The results indicate that LAD is able to characterize different types of accidents with an average classification accuracy of 72–74%, which is satisfactory when compared with other studies dealing with large amounts of data where such a level of accuracy is considered adequate. The paper shows that the quantitative information provided by LAD about the patterns generated can be used as a logical way to prioritize risk factors. This prioritization helps safety practitioners make decisions regarding safety measures for machines. - Highlights: • LAD is presented as an innovative approach to prevent machinery-related accidents. • LAD is applied to a very small database of belt-conveyor-related accidents. • Despite scarce data, LAD generates patterns with adequate classification accuracy. • The patterns characterize different types of belt-conveyor-related accidents. • The patterns are useful to belt conveyor risk identification and risk estimation.

Medical aspects of radiation accidents

International Nuclear Information System (INIS)

Messerschmidt, O.

1990-01-01

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

Cell Phone-Related Near Accidents Among Young Drivers: Associations With Mindfulness.

Science.gov (United States)

Terry, Christopher P; Terry, Danielle L

2015-01-01

Cell phone use while driving (CPWD) has been shown to significantly reduce driver safety. This is a particular concern among young drivers who possess less driving experience and tend to engage in high rates of cell phone use. The present study identified psychological predictors of near accidents related to CPWD among a sample of 385 college student drivers. Participants answered a series of questions regarding their use of a cell phone while driving and completed measures of mindfulness, polychronicity, and intrusive thinking. Students who reported talking on their phone or texting more frequently while driving reported a higher incidence of near accidents related to each behavior. However, after controlling for CPWD, multiple regression analysis indicated that those who reported experiencing more cell phone-related intrusive thoughts also experienced more near accidents. Furthermore, two facets of mindfulness--acting with awareness and nonjudging of inner experience--were negatively associated with near accidents. These findings suggest that individuals who are more aware of the present moment and accepting of their affective responses may better regulate their attention while using a cell phone behind the wheel.

[Factors associated with work-related accidents in the informal commercial sector].

Science.gov (United States)

Rios, Marcela Andrade; Nery, Adriana Alves; Rios, Polianna Alves Andrade; Casotti, Cezar Augusto; Cardoso, Jefferson Paixão

2015-06-01

This study aimed to estimate the incidence of non-fatal work-related accidents in the informal commercial sector and analyze associated socio-demographic, occupational, workplace, and health factors, in a cross-sectional survey of 434 workers in the business district of Jequié, Bahia State, Brazil, in 2013. Logistic regression was used to assess factors associated with accidents. Incidence of accidents in the previous 12 months was estimated at 32.3%, and multivariate analysis showed higher odds of accidents in male sex workers (OR = 1.61), young individuals (OR = 4.62), meat or poultry workers (OR = 9.55), and workers performing heavy physical work (OR = 1.71). The results show the need for public policies to prevent accidents in the informal commercial sector.

Environmental behavior of the radionuclides released from the Fukushima Daiichi Nuclear Power Plant accident

International Nuclear Information System (INIS)

Yamazaki, Hideo

2014-01-01

The environmental behavior of radioactive nuclides released from the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in eastern Japan was investigated. The radioactive pollution of environmental samples, including airborne dust, soil, sediment, fish, and other organisms was described. It was evaluated for environmental behavior and fate of the radioactive material from the spatial and temporal distribution of the radioactive nuclides. In Higashiosaka City about 600 km away from FDNPS, it begins to detect the radioactive nuclides in the airborne dust from 25th March 2011. Radioactive fission products 95 Zr- 95 Nb was detected on 18th April. The concentrations of 131 I, 134 Cs, and 137 Cs in the soil collected from Fukushima City were 126000, 14000, and 14200 Bq/kg on 19th March 2011 and 12800, 13200, and 13700 Bq/kg on 26th March 2011, respectively. The concentrations of 131 I, 134 Cs, and 137 Cs in the soil samples collected from March-June 2011 from study sites in metropolitan area and Kanto region ranged from nd to 91900, 59 to 16100, and 69 to 17600 Bq/kg, respectively. (Concentrations of 131 I were done decay correction to the value of 16th March) Radioactivities in fish samples collected from off FDNPS, Tokyo Bay, and Kejonuma Pond were measured. The radioactive contamination of forest ecosystem was also investigated. Two processes are involved in the radioactive contamination of the environment from the FDNPS accident. One is contamination by radioactive nuclides released from the hydrogen explosion. Leakage of contaminated cooling water to the ocean is in other important environmental pollution. We must continue carefully monitoring of radioactive nuclides in the environment. (author)

[Accident cause masculinity?--Gender-related issues of accident victims between prevention and coping in Kaiserreich and Weimarer Republik].

Science.gov (United States)

Knoll-Jung, Sebastian

2015-01-01

Occupational accidents in industrial workplaces are a specific health problem for man. Therefore it seems adequate to use masculinities as a category of research in this field. For the Kaiserreich and the Weimarer Republik it shows that male workers relating to their danger awareness and behavior, prevention, accident causes and coping strategies are settled in an area of conflict between a hard workplace environment and the family. On the basis of health practices of the accident victims it appears that there are different forms of labor masculinities. They have an important influence on all levels of an occupational accident from the endangerment to the success of the treatment. Through a critical use of the category academic void can be shown and alternative explanatory models can be offered.

Mitigation of release of volatile iodine species during severe reactor accidents - a novel reliable process of safety technology

International Nuclear Information System (INIS)

Guentay, S.; Bruchertseifer, H.

2010-01-01

In severe accidents, a significant risk for public health may be generated as a result of release of the gaseous iodine species into the environment through the containment leaks or containment venting filter systems with low retention efficiency. The elemental iodine and volatile organic iodides are the main gaseous iodine species in the containment. Potential release of large quantities of gaseous elemental iodine from the reactor coolant system or its radiolytic generation in the containment sump constitute the key source of gaseous elemental iodine in containment atmosphere. Iodine paint reactions as well as the reaction of iodine with organic residuals in sump water are the main mechanisms for the generation of high volatile organic iodides in the containment. Although very much desired, significant research activities conducted in 70's unfortunately did not create any technically feasible solution to mitigate iodine release into the environment under prevailing conditions. Development of a process leading to a fast, comprehensive and reliable retention of volatile iodine species in aqueous solution with an aim to implement for the severe accident management applications has been subject of a research project in the recent years at Paul Scherrer Institut. The process developed utilizes simultaneous use of two customary technical chemical additives in an aqueous solution. The results of the experimental program have demonstrated a fast and reliable destruction of high volatile organic iodine species and fast reduction of elemental iodine into iodide ions in aqueous solutions and an efficient mitigation of the re-formation of gaseous iodine from iodide ions. Investigations covered a broad range of anticipated severe accident conditions in the containment. The project additionally focused on possible application of the process to existing containment venting filter systems, specifically as a passive add-on for back-fitting. This paper describes the process

40 CFR 68.42 - Five-year accident history.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Five-year accident history. 68.42... (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Hazard Assessment § 68.42 Five-year accident history. (a) The owner or operator shall include in the five-year accident history all accidental releases from...

Source term analysis in severe accident induced by large break loss of coolant accident coincident with ship blackout for ship reactor

International Nuclear Information System (INIS)

Zhang Yanzhao; Zhang Fan; Zhao Xinwen; Zheng Yingfeng

2013-01-01

Using MELCOR code, the accident analysis model was established for a ship reactor. The behaviors of radioactive fission products were analyzed in the case of severe accident induced by large break loss of coolant accident coincident with ship blackout. The research mainly focused on the behaviors of release, transport, retention and the final distribution of inert gas and CsI. The results show that 83.12% of inert gas releases from the core, and the most of inert gas exists in the containment. About 83.08% of CsI release from the core, 72.66% of which is detained in the debris and the primary system, and 27.34% releases into the containment. The results can give a reference for the evaluation of cabin dose and nuclear emergency management. (authors)

Aerosols behavior inside a PWR during an accident

International Nuclear Information System (INIS)

Hervouet, C.

1983-01-01

During very hypothetical accidents occurring in a pressurized water ractor, radioactive aerosols can be released, during core-melt, inside the reactor containment building. A good knowledge of their behavior in the humid containment atmosphere (mass concentration and size distribution) is essential in order to evaluate their harmfulness in case of environment contamination and to design possible filtration devices. Accordingly the Safety Analysis Department of the Atomic Energy Commission uses several computer models, describing the particle formation (BOIL/MARCH), then behavior in the primary circuits (TRAP-MELT), and in the reactor containment building (AEROSOLS-PARFDISEKO-III B). On the one hand, these models have been improved, in particular the one related to the aerosol formation (nature and mass of released particles) using recent experimental results. On the other hand, sensitivity analyses have been performed with the AEROSOLS code which emphasize the particle coagulation parameters: agglomerate shape factors and collision efficiency. Finally, the different computer models have been applied to the study of aerosol behavior during a 900 MWe PWR accident: loss-of-coolant-accident (small break with failure of all safety systems) [fr

[Incidence of non-fatal work-related accidents in Southeast Brazil].

Science.gov (United States)

Cordeiro, Ricardo; Prestes, Simone Cristina Chiodi; Clemente, Ana Paula Grotti; Diniz, Cíntia Ségre; Sakate, Mirian; Donalisio, Maria Rita

2006-02-01

Incidence of work-related accidents in Botucatu, São Paulo, Brazil, was estimated according to gender, age, employment status, occupation, and type of work. A household survey was conducted by systematic random group sampling (195 census tracts). Information was collected from all residents 10 years or older in each household. Of those who had worked during the 90 days prior to the interview, we obtained information on occupation, job position, and employment contract. The study included 9,626 households (sample fraction 0.26). The proportion of non-fatal work accidents in the municipal area was 3.3% (95%CI: 2.7-3.9), higher for men 4.5% (95%CI: 3.6-5.5) and varying with type of employment contract and occupation. Compared to results from previous studies, we observed a decline in work-related accident risk.

National preparedness guide for exiting the emergency phase subsequent to a nuclear accident causing moderate, short-term release on French soil - working document, version 0, May 2010

International Nuclear Information System (INIS)

2010-05-01

This National Guide provides basic explanations and methods to assist in drawing up a local plan for the emergency phase way-out, subsequent to a nuclear accident of moderate magnitude causing short-term (under 24 hours) radioactive release, which could possibly occur in France. The accident situations considered in this Guide have little likelihood of arising and are representative of environmental contamination accidents that might occur at French nuclear facilities covered by a special intervention plan (plan particulier d'intervention, PPI). Such accidents may cause environmental contamination warranting action for post-accident impact management within a range of ten to fifty kilometres from the accident site. To provide some perspective, the accidents considered here would be classified Levels 3, 4 or 5 (incidents or accidents causing release into the environment) on the INES scale customarily used to help the public and media to immediately understand the severity of an incident or accident in the nuclear field. This Guide was drawn up subsequently to the work carried out by the Steering Committee on Post- Accident Phase Management in the Event of a Nuclear Accident or Radiological Emergency Situation (CODIRPA), instituted by the French Nuclear Safety Authority (ASN) in June 2005, and in charge of setting out the basic principles underlying the management of nuclear post-accident situations. This version of the Guide shall be updated on the basis of the operating experience feedback received on its use. The Guide is a planning tool, intended for the Prefectures of department where a basic nuclear facility PPI has been instituted. Its purpose is to enable Prefects to plan and effectively conduct preparedness measures at the local level with the aim of winding down the emergency phase, actively involving all of the relevant actors for this purpose. The exit period from the emergency phase is defined as extending approximately one week from the end of the

Accident sequence precursor events with age-related contributors

Energy Technology Data Exchange (ETDEWEB)

Murphy, G.A.; Kohn, W.E.

1995-12-31

The Accident Sequence Precursor (ASP) Program at ORNL analyzed about 14.000 Licensee Event Reports (LERs) filed by US nuclear power plants 1987--1993. There were 193 events identified as precursors to potential severe core accident sequences. These are reported in G/CR-4674. Volumes 7 through 20. Under the NRC Nuclear Plant Aging Research program, the authors evaluated these events to determine the extent to which component aging played a role. Events were selected that involved age-related equipment degradation that initiated an event or contributed to an event sequence. For the 7-year period, ORNL identified 36 events that involved aging degradation as a contributor to an ASP event. Except for 1992, the percentage of age-related events within the total number of ASP events over the 7-year period ({approximately}19%) appears fairly consistent up to 1991. No correlation between plant ape and number of precursor events was found. A summary list of the age-related events is presented in the report.

Accident for natural gas well with hydrogen sulfide in relation to nuclear power plant siting

International Nuclear Information System (INIS)

Tan Chengjun; Shangguang Zhihong; Sha Xiangdong

2010-01-01

In order to make assessment to the potential impact from accident of natural gas wells with hydrogen sulfide on the habitability of main control room of nuclear power plant (NPP), several assumptions such as source terms of maximum credible accident, conservative atmospheric conditions and release characteristics were proposed in the paper, and the impact on the habitability of main control room was evaluated using toxicity thresholds recommended by foreign authority. Case results indicate that the method can provide the reference for the preliminary assessment to external human-induced events during the siting phrase of NPP. (authors)

Supplemental analysis of accident sequences and source terms for waste treatment and storage operations and related facilities for the US Department of Energy waste management programmatic environmental impact statement

International Nuclear Information System (INIS)

Folga, S.; Mueller, C.; Nabelssi, B.; Kohout, E.; Mishima, J.

1996-12-01

This report presents supplemental information for the document Analysis of Accident Sequences and Source Terms at Waste Treatment, Storage, and Disposal Facilities for Waste Generated by US Department of Energy Waste Management Operations. Additional technical support information is supplied concerning treatment of transuranic waste by incineration and considering the Alternative Organic Treatment option for low-level mixed waste. The latest respirable airborne release fraction values published by the US Department of Energy for use in accident analysis have been used and are included as Appendix D, where respirable airborne release fraction is defined as the fraction of material exposed to accident stresses that could become airborne as a result of the accident. A set of dominant waste treatment processes and accident scenarios was selected for a screening-process analysis. A subset of results (release source terms) from this analysis is presented

Probabilistic Assessment of Severe Accident Consequence in West Bangka

Science.gov (United States)

Sunarko; Su'ud, Zaki

2017-07-01

Probabilistic dose assessment for severe accident condition is performed for West Bangka area. Source-term from WASH-1400 reactor analysis is used as a conservative release scenario for 1000 MWe PWR. Seven groups of isotopes are used in the simulation based on core inventory and release fraction. Population distribution for Muntok district and the area within a 100 km radius is obtained from 2014 data. Meteorological data is provided through cyclic sampling from a database containing two-year site-specific hourly records in 2014-2015 periods. PC-COSYMA segmented plume dispersion code is used to investigate the assumed the consequence of the accident scenario. The result indicates that early or deterministic effect is important for areas close the release point while long-term or stochastic effect is related to population distribution and covers area of up to 100 km from the release point. The mean annual expected values for early mortality and late mortality for the population within 100 km radius from Muntok site are 2.38×10-4 yr -1 and 1.33×10-3 yr -1 respectively.

General aviation accidents related to exceedance of airplane weight/center of gravity limits.

Science.gov (United States)

Boyd, Douglas D

2016-06-01

Obesity, affects a third of the US population and its corollary occupant weight adversely impacts safe flight operations. Increased aircraft weight results in longer takeoff/landing distances, degraded climb gradients and airframe failure may occur in turbulence. In this study, the rate, temporal changes, and lethality of accidents in piston-powered, general aviation aircraft related to exceeding the maximum aircraft weight/center of gravity (CG) limits were determined. Nation-wide person body mass were from the National Health and Nutrition Examination Survey. The NTSB database was used to identify accidents related to operation of aircraft outside of their weight/CG envelope. Statistical analyses employed T-tests, proportion tests and a Poisson distribution. While the average body mass climbed steadily (p<0.001) between 1999 and 2014 the rate of accidents related to exceedance of the weight/CG limits did not change (p=0.072). However, 57% were fatal, higher (p<0.001) than the 21% for mishaps attributed to other causes/factors. The majority (77%) of accidents were due to an overloaded aircraft operating within its CG limits. As to the phase of flight, accidents during takeoff and those occurring enroute carried the lowest (50%) and highest (85%) proportion of fatal accidents respectively. While the rate of general aviation accidents related to operating an aircraft outside of its weight/CG envelope has not increased over the past 15 years, these types of accidents carry a high risk of fatality. Airmen should be educated as to such risks and to dispel the notion held by some that flights may be safely conducted with an overloaded aircraft within its CG limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Work-related accidents in traditional fishermen from the Medium Araguaia River region, Tocantins, Brazil].

Science.gov (United States)

Garrone Neto, Domingos; Cordeiro, Ricardo Carlos; Haddad, Vidal

2005-01-01

This is a cross-sectional study of work-related accidents among traditional fishermen in the Medium Araguaia River region of Tocantins, Brazil. From June to August 2002, fishermen from the Municipality of Araguacema were interviewed about the organization of their work activities and work-related accidents during the previous six months. Of the 92 participating fishermen, 56 reported having suffered a work-related accident (annual incidence was 82.6%). Some 95.7% of those interviewed did not regularly pay social security insurance as self-employed workers and were not aware of their social rights and duties. For fishermen reporting accidents, this proportion was 98.2%. Approximately 23.0% had another work activity, mainly as construction workers (47.6%) or sport-fishing guides (23.9%). Injuries inflicted by aquatic animals were the main form of accidents (about 86.0%). From these results, it is apparent that accidents from aquatic animals are an important health hazard, in some cases causing temporary work incapacity.

Facilitating relative comparisons of health impacts from postulated accidents in environmental impact statements

International Nuclear Information System (INIS)

Mueller, C.J.

1996-01-01

Current US Department of Energy (DOE) guidance on the performance of accident analyses supported an environmental impact statement (EIS) stresses a graded approach that emphasizes the most important risks, calls for the evaluation of frequencies as well as consequences for severe accident scenarios, and discourages the use of bounding analyses that confound risk comparisons among EIS alternatives. This paper discusses methods in probabilistic risk analysis that were developed and applied in defining accidents and generating radiological source terms for the DOE Draft Waste Management Programmatic Environmental Impact Statement (WM PEIS); publication of the Final WM PEIS is due in late summer 1996. The strengths and shortcomings of the cited probabilistic risk analysis methods used to evaluate facility accidents are addressed, both as they relate to the WM PEIS and as they relate to more general EIS applications. Key guidance is discussed that was developed by DOE and used in shaping the techniques cited herein for application in an EIS. Related perceptions on accidents observed from the public comment process for the WM PEIS are cited. Finally, recommendations are made on the basis of needs as well as lessons learned in implementing the accident analysis for the WM PEIS

Inventory of accidents and losses at sea involving radioactive material

International Nuclear Information System (INIS)

2001-09-01

The present report describes the content of the inventory of accidents and losses at sea involving radioactive material. It covers accidents and losses resulting in the actual release of radioactive materials into the marine environment and also those which have the potential for release. For completeness, records of radioactive materials involved in accidents but which were recovered intact from the sea are also reported. Information on losses of sealed sources resulting in actual or potential release of activity to the marine environment nad of sealed sources that were recovered intact is also presented

Guidelines for calculating radiation doses to the public from a release of airborne radioactive material under hypothetical accident conditions in nuclear reactors

International Nuclear Information System (INIS)

1989-09-01

This Standard provides guidelines and a methodology for calculating effective doses and thyroid doses to people (either individually or collectively) in the path of airborne radioactive material released from a nuclear facility following a hypothetical accident. The specific radionuclides considered in the Standard are those associated with substances having the greatest potential for becoming airborne in reactor accidents (eg, tritium (HTO), noble gases and their daughters (Kr-Rb, Xe-Cs), and radioiodines (I)); and certain radioactive particulates (eg, Cs, Ru, Sr, Te) that may become airborne under exceptional circumstances

Numerical modelling and parametric study of the atmospheric dispersion after radionuclide releases: the Chernobyl accident and the Algeciras incident. Comparison with observation data

International Nuclear Information System (INIS)

Minier, Y.; Mathieu, A.; Quelo, D.; Sportisse, B.; Isnard, O.; Krysta, M.; Bocquet, M.

2006-01-01

Full text: The attempts of modelling the release following upon the Chernobyl accident and the Algeciras incident are reported. Computing power and observation database are used for sensitivity and parametric studies. The meteorological mesoscale model MM5 is nudged with the ERA-40 reanalysis to simulate the meteorological conditions used by the dispersion model, POLAIR3D. In case of the Chernobyl accident the points of interest are many: the representativity of the meteorological simulations is evaluated using observations with a special focus on precipitation events. The radionuclide dispersion, the dry deposition and scavenging simulated by POLAIR3D are compared with European measurements of activities and depositions. Results of the sensitivity studies are done to evaluate the impact of the deposition parameterizations and source-term characteristics (height of release, quantities). The time dynamic of the contaminated cloud is also investigated with regard to the arrival time on different countries. Similarly, for the Algeciras release, sensitivity to the meteorological fields, source term and depletion processes are analyzed. For the available activity concentrations in the air, data-model comparisons are performed. (author)

A summary of the assessment of fuel behaviour, fission product release and pressure tube integrity following a postulated large loss-of-coolant accident

International Nuclear Information System (INIS)

Langman, V.J.; Weaver, K.R.

1984-05-01

The Ontario Hydro analyses of fuel and pressure tube temperatures, fuel behaviour, fission product release and pressure tube integrity for large break loss-of-coolant accidents in Bruce A or Pickering A have been critically reviewed. The determinations of maximum fuel temperatures and fission product release are very uncertain, and pressure tube integrity cannot be assured where low steam flows are predicted to persist for times on the order of minutes

MELCOR modeling of Fukushima unit 2 accident

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-15

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

Vehicle accidents related to sleep: a review.

Science.gov (United States)

Horne, J; Reyner, L

1999-05-01

Falling asleep while driving accounts for a considerable proportion of vehicle accidents under monotonous driving conditions. Many of these accidents are related to work--for example, drivers of lorries, goods vehicles, and company cars. Time of day (circadian) effects are profound, with sleepiness being particularly evident during night shift work, and driving home afterwards. Circadian factors are as important in determining driver sleepiness as is the duration of the drive, but only duration of the drive is built into legislation protecting professional drivers. Older drivers are also vulnerable to sleepiness in the mid-afternoon. Possible pathological causes of driver sleepiness are discussed, but there is little evidence that this factor contributes greatly to the accident statistics. Sleep does not occur spontaneously without warning. Drivers falling asleep are unlikely to recollect having done so, but will be aware of the precursory state of increasing sleepiness; probably reaching a state of fighting off sleep before an accident. Self awareness of sleepiness is a better method for alerting the driver than automatic sleepiness detectors in the vehicle. None of these have been proved to be reliable and most have shortcomings. Putative counter measures to sleepiness, adopted during continued driving (cold air, use of car radio) are only effective for a short time. The only safe counter measure to driver sleepiness, particularly when the driver reaches the stage of fighting sleep, is to stop driving, and--for example, take a 30 minute break encompassing a short (driving while sleepy, and driving at vulnerable times of the day.

Prevalence of sleep-related accidents among drivers in Saudi Arabia

Science.gov (United States)

BaHammam, Ahmad S.; Alkhunizan, Muath A.; Lesloum, Rabea H.; Alshanqiti, Amer M.; Aldakhil, Abdulrahman M.; Pandi-Perumal, Seithikurippu R.; Sharif, Munir M.

2014-01-01

INTRODUCTION: The prevalence of sleepy driving and sleep-related accidents (SRA) varies widely, and no data exist regarding the prevalence of sleepy driving in Saudi Arabia. Therefore, this study was designed to determine the prevalence and predictors of sleepy driving, near-misses, and SRA among drivers in Saudi Arabia. MATERIALS AND METHODS: A questionnaire was developed to assess sleep and driving in detail based on previously published data regarding sleepy driving. The questionnaire included 50 questions addressing socio-demographics, the Epworth Sleepiness Scale (ESS), driving items, and the Berlin Questionnaire. In total, 1,219 male drivers in public places were interviewed face-to-face. RESULTS: The included drivers had a mean age of 32.4 ± 11.7 years and displayed a mean ESS score of 7.2 ± 3.8. Among these drivers, 33.1% reported at least one near-miss accident caused by sleepiness. Among those who had actual accidents, 11.6% were attributed to sleepiness. In the past six months, drivers reported the following: 25.2% reported falling asleep at least once during, driving and 20.8% had to stop driving at least once because of severe sleepiness. Young age, feeling very sleepy during driving, and having at least one near-miss accident caused by sleepiness in the past six months were the only predictors of accidents. CONCLUSION: Sleepy driving is prevalent among male drivers in Saudi Arabia. Near-miss accidents caused by sleepiness are an important risk factor for car accidents and should be considered as a strong warning signal of future accidents. PMID:25276244

Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

Science.gov (United States)

Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

2011-12-01

Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

The Chernobyl reactor accident source term: development of a consensus view

International Nuclear Information System (INIS)

Devell, L.; Guntay, S.; Powers, D.A.

1995-11-01

Ten years after the reactor accident at Chernobyl, a great deal more data is available concerning the events, phenomena, and processes that took place. The purpose of this document is to examine what is known about the radioactive materials released during the accident, a task that is substantially more difficult than it might first appear to be. The Chernobyl station, like other nuclear power plants, was not instrumented to characterize a disastrous accident. The accident was peculiar in the sense that radioactive materials were released, at least initially, in an exceptionally energetic plume and were transported far from the reactor site. Release of radioactivity from the plant continued for several days. Characterization of the contamination caused by the releases of radioactivity has had a much lower priority than remediation of the contamination. Consequently, an assessment of the Chernobyl accident source term must rely to a significant extent on inferential evidence. The assessment presented here begins with an examination of the core inventories of radioactive materials. In subsequent sections of the report, the magnitude and timing of the releases of radioactivity are described. Then, the composition, chemical forms, and physical forms of the releases are discussed. A number of more recent publications and results from scientists in Russia and elsewhere have significantly improved the understanding of the Chernobyl source term. Because of the special features of the reactor design and the peculiarities of the Chernobyl accident, the source term for the Chernobyl accident is of limited applicability to the safety analysis of other types of reactors

Analysis of accidental UF6 releases

International Nuclear Information System (INIS)

Fan Yumao; Tan Rui; Gao Qifa

2012-01-01

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

The Chernobyl accident: Causes and consequences

International Nuclear Information System (INIS)

Malinauskas, A.P.

1987-01-01

Two explosions, one immediately following the other, in Unit 4 of the Chernobyl nuclear power station in the Soviet Union signaled the worst disaster ever to befall the commercial nuclear power production industry. This accident, which occurred at 1:24 a.m. on April 26, 1986, resulted from an almost incredible series of operational errors associated, ironically, with an attempt to enhance the capability of the reactor to safely accommodate station blackout accidents (i.e., accidents arising from a loss of station electrical power). Disruption of the core, due to a prompt criticality excursion, resulted in the destruction of the core vault and reactor building and the sudden dispersal of about 3% of the fuel from the core region into the environment. Lesser but significant releases of radioactivity continued through May 6, 1986, before attempts to certain the radioactivity and cool the remnants of the core were successful. The amount and composition of material released in the course of the accident remain somewhat uncertain, and inconsistencies in the release estimates are evident. The Soviet estimates, in addition to the dispersal of about 3% of the fuel, include complete release of the noble gas core inventory, 20% of the fission product iodine inventory, 15% of the tellurium inventory, and 10 to 13% of the fission product cesium inventory. The iodine and cesium release estimates are not consistent with the noble gas values, and are as much as a factor of two less than some estimates made by experts outside the Soviet Union

Chernobyl accident and Denmark

International Nuclear Information System (INIS)

1986-12-01

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

Monitoring Cs-134 and 137 released by Fukushima Dai-ichi Nuclear Power Plant accident in ground, soil, and stream waters

Science.gov (United States)

Tsujimura, Maki; Onda, Yuichi; Hada, Manami; Ishwar, Pun; Abe, Yutaka

2013-04-01

Due to Fukushima Dai-ichi Nuclear power plant accident occurred in March 2011, large amount of radionuclides was released into the atmosphere and was fallen onto ground by rainfall. Few researches have monitored radioactive cesium dynamics in whole hydrological cycle system such as groundwater, soil water, spring water and stream water. Thus, the purpose of this study is to monitor concentration of radioactive cesium in those waters in time series in the headwaters. We have performed an intensive monitoring at three small mountainous catchments in Yamakiya district, Kawamata town, Fukushima prefecture, locating 35 km northwest from Fukushima Dai-ichi Nuclear Power Plant since June 2011, also we consider the movement of radioactive cesium and its relation with the hydrological cycle.

On the sequence and consequences of the Chernobyl reactor accident

Energy Technology Data Exchange (ETDEWEB)

Hennies, H H

1986-01-01

A serious reactor accident occurred on April 26, 1986 at Chernobyl near Kiev (Soviet Union) where, after melting of the core, there was a considerable release of radioactivity to the environment and to the atmosphere. The radioactivity release caused irradiation of the operating staff, which led to 24 deaths by June 1986. Hardly anything is known about the irradiation of the environment of the reactor plant, but the population within a radius of 30 km was evacuated. The radioactivity released into the atmosphere spread all over Europe, and Germany was affected a few days after the accident. The article gives a short description of the plant which suffered the accident, one tries to describe the course of the accident and to discuss the applicability to German plants.

Methods and data for HTGR fuel performance and radionuclide release modeling during normal operation and accidents for safety analysis

International Nuclear Information System (INIS)

Verfondern, K.; Martin, R.C.; Moormann, R.

1993-01-01

The previous status report released in 1987 on reference data and calculation models for fission product transport in High-Temperature, Gas-Cooled Reactor (HTGR) safety analyses has been updated to reflect the current state of knowledge in the German HTGR program. The content of the status report has been expanded to include information from other national programs in HTGRs to provide comparative information on methods of analysis and the underlying database for fuel performance and fission product transport. The release and transport of fission products during normal operating conditions and during the accident scenarios of core heatup, water and air ingress, and depressurization are discussed. (orig.) [de

Key Characteristics of Combined Accident including TLOFW accident for PSA Modeling

Energy Technology Data Exchange (ETDEWEB)

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

2015-05-15

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

A survey on hazardous materials accidents during road transport in China from 2000 to 2008

International Nuclear Information System (INIS)

Yang Jie; Li Fengying; Zhou Jingbo; Zhang Ling; Huang Lei; Bi Jun

2010-01-01

A study of 322 accidents that occurred during the road transport of hazardous materials (hazmat) in China from 2000 to 2008 was carried out. The results showed an increase in the frequency of accidents from 2000 to 2007 and a decline in 2008. More than 63% of the accidents occurred in the eastern coastal areas, 25.5% in the central inland areas, and only 10.9% in the western remote areas. The most frequent types of accident were releases (84.5%), followed by gas clouds (13.0%), fires (10.2%), no substance released due to timely measures (9.9%), and explosions (5.9%). The spatial distribution, the causes and consequences of the accidents related to the population (e.g., number of people killed, injured, evacuated, or poisoned), and environment elements were analyzed. Finally, conclusions are drawn concerning the need to improve certain safety measures in the road transport of hazmat in China.

Examination of a measuring method for judging the influence of fallout released by the accident of the Fukushima Dai-ichi NPS

Energy Technology Data Exchange (ETDEWEB)

Onishi, Yuko; Yoshii, Taiki; Kawasaki, Satoru [Japan Nuclear Energy Safety Organization, Nulcear Fuel Cycle and Radioactive Waste Management Safety Dept., Tokyo (Japan)

2012-07-15

Radioactive nuclides were released in the atmosphere by the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station in March, 2011, and they are detected on the materials that had no artificial radioactive nuclides before the accident. Confronted with this situation, NISA issued a guideline titled 'A guideline regarding treatment of materials in nuclear facilities considering the influence of fallout released from the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station' on March 30, 2012. The guideline shows that after judging whether there is the influence of fallout or not, the conventional clearance and NR systems can be used when there is no influence of fallout. On the other hand, the special treatment is required when it is judged that there is the influence. This report describes that a specific example of measuring method of the surface contamination of the materials for the judgment of the influence of fallout. 'The precautionary measurement' defined in NR system is useful for the judgment of the influence of fallout. The criterion of the judgment is the theoretical detection limit. Sampling points for the measurement should be selected depending on expected contamination status of the survey target, considering the site area, the states of facilities or equipments and airflow from outside of the facilities. Sampling number for the fallout should be greater than equal to 10. (author)

Examination of a measuring method for judging the influence of fallout released by the accident of the Fukushima Dai-ichi NPS

International Nuclear Information System (INIS)

Onishi, Yuko; Yoshii, Taiki; Kawasaki, Satoru

2012-07-01

Radioactive nuclides were released in the atmosphere by the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station in March, 2011, and they are detected on the materials that had no artificial radioactive nuclides before the accident. Confronted with this situation, NISA issued a guideline titled 'A guideline regarding treatment of materials in nuclear facilities considering the influence of fallout released from the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station' on March 30, 2012. The guideline shows that after judging whether there is the influence of fallout or not, the conventional clearance and NR systems can be used when there is no influence of fallout. On the other hand, the special treatment is required when it is judged that there is the influence. This report describes that a specific example of measuring method of the surface contamination of the materials for the judgment of the influence of fallout. 'The precautionary measurement' defined in NR system is useful for the judgment of the influence of fallout. The criterion of the judgment is the theoretical detection limit. Sampling points for the measurement should be selected depending on expected contamination status of the survey target, considering the site area, the states of facilities or equipments and airflow from outside of the facilities. Sampling number for the fallout should be greater than equal to 10. (author)

An epidemiologic survey of road traffic accidents in Iran: analysis of driver-related factors

Directory of Open Access Journals (Sweden)

Moafian Ghasem

2013-06-01

Full Text Available 【Abstract】Objective: Road traffic accident (RTA and its related injuries contribute to a significant portion of the burden of diseases in Iran. This paper explores the as-sociation between driver-related factors and RTA in the country. Methods: This cross-sectional study was conducted in Iran and all data regarding RTAs from March 20, 2010 to June 10, 2010 were obtained from the Traffic Police Department. We included 538 588 RTA records, which were classified to control for the main confounders: accident type, final cause of accident, time of accident and driver-related factors. Driver-related factors included sex, educational level, license type, type of injury, duration between accident and getting the driving license and driver’s error type. Results: A total of 538 588 drivers (91.83% male, sex ratio of almost 13:1 were involved in the RTAs. Among them 423 932 (78.71% were uninjured; 224 818 (41.74% had a diploma degree. Grade 2 driving license represented the highest proportion of all driving licenses (290 811, 54.00%. The greatest number of accidents took place at 12:00-13:59 (75 024, 13.93%. The proportion of drivers involved in RTAs decreased from 15.90% in the first year of getting a driving license to 3.13% after 10 years’ of driving experience. Ne-glect of regulations was the commonest cause of traffic crashes (345 589, 64.17%. Non-observance of priority and inattention to the front were the most frequent final causes of death (138 175, 25.66% and 129 352, 24.02%, respectively. We found significant association between type of acci-dent and sex, education, license type, time of accident, final cause of accident, driver’s error as well as duration between accident and getting the driving license (all P<0.001. Conclusion: Our results will improve the traffic law enforcement measures, which will change inappropriate be-havior of drivers and protect the least experienced road users. Key words: Accidents, traffic; Automobile

A study of maintenance-related major accident cases in the 21st century

OpenAIRE

Okoh, Peter; Haugen, Stein

2014-01-01

This paper is based on a review of 183 detailed, major accident investigation and analysis reports related to the handling, processing and storage of hydrocarbons and hazardous chemicals over a decade from 2000 to 2011. The reports cover technical, human and organizational factors. In this paper, the Work and Accident Process (WAP) classification scheme is applied to the accident reports with the intention of investigating to what extent maintenance has been a cause of major accidents and wha...

Radioactive releases into the environment under accidental conditions

International Nuclear Information System (INIS)

Beninson, D.

1976-01-01

Although accidents involving the release of radioactive materials and the unplanned exposure of people can occur at any stage of the nuclear fuel cycle, most attention has been focused on reactor accidents. Although no power reactor accidents involving exposure of the public have yet occured, it should be recognized that the probability of such accidental releases cannot be reduced to zero. Since the inventory of radioactive materials in power reactors is very large, it is usual to postulate, for safety assessments, that a release of fission products takes place in spite of all protective measures. This postulated release is of importance for reactor siting and for preparing emergency plans. (HP) [de

The nature of reactor accidents

International Nuclear Information System (INIS)

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

1981-01-01

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

Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers.

Science.gov (United States)

da Silva, Luiz Almeida; Robazzi, Maria Lúcia do Carmo Cruz; Terra, Fábio de Souza

2013-01-01

To investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. Correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. Motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

Epidemiology of road traffic accidents in adults. A systematic review

Directory of Open Access Journals (Sweden)

Krzysztof Goniewicz

2017-07-01

Full Text Available Road accidents are a serious problem of the modern world. They are one of the main causes of injuries and are the third most numerous cause of death. Every year, about one million people, adults and children, die on the roads and several millions are injured. Mortality rate due to injuries from road accidents amounts to 2,2% of all deaths in the world. The research presents a mechanism of traffic accidents, pathophysiology of injury, partition of car accidents and characterized the insults of victims in various types of automobile accidents. Injuries resulting from road accidents have numerous substantial consequences as they are related with releasing large amounts of kinetic energy which must be absorbed. Kinetic energy absorbing is the basic mechanism of injury arising during road accidents. In apprising an automobile accident should take into consideration the type of the car accident and the extent of damage to the vehicle People participating in road accidents of high energy are especially endangered with substantial injuries. There is a close relationship between the rate of vehicle damages and seriousness of casualties' injuries.

Fission product release from HTGR fuel under core heatup accident conditions - HTR2008-58160

International Nuclear Information System (INIS)

Verfondern, K.; Nabielek, H.

2008-01-01

Various countries engaged in the development and fabrication of modern fuel for the High Temperature Gas-Cooled Reactor (HTGR) have initiated activities of modeling the fuel and fission product release behavior with the aim of predicting the fuel performance under operating and accidental conditions of future HTGRs. Within the IAEA directed Coordinated Research Project CRP6 on 'Advances in HTGR Fuel Technology Development' active since 2002, the 13 participating Member States have agreed upon benchmark studies on fuel performance during normal operation and under accident conditions. While the former has been completed in the meantime, the focus is now on the extension of the national code developments to become applicable to core heatup accident conditions. These activities are supported by the fact that core heatup simulation experiments have been resumed recently providing new, highly valuable data. Work on accident performance will be - similar to the normal operation benchmark - consisting of three essential parts comprising both code verification that establishes the correspondence of code work with the underlying physical, chemical and mathematical laws, and code validation that establishes reasonable agreement with the existing experimental data base, but including also predictive calculations for future heating tests and/or reactor concepts. The paper will describe the cases to be studied and the calculational results obtained with the German computer model FRESCO. Among the benchmark cases in consideration are tests which were most recently conducted in the new heating facility KUEFA. Therefore this study will also re-open the discussion and analysis of both the validity of diffusion models and the transport data of the principal fission product species in the HTGR fuel materials as essential input data for the codes. (authors)

Subway train-related fatalities in New York City: accident versus suicide.

Science.gov (United States)

Lin, Peter T; Gill, James R

2009-11-01

We examined the characteristics of subway train-related fatalities in New York City between Jan. 1, 2003 and May 31, 2007 in order to determine which factors are useful in differentiating accident from suicide. Subway train-related deaths with homicide and undetermined manners also are included. During this period, there were 211 subway train-related fatalities. The manners of death were: suicide (n = 111), accident (n = 76), undetermined (n = 20), and homicide (n = 4). The causes of death were blunt trauma (n = 206) and electrocution (n = 5). Torso transection and extremity amputation were more frequent in suicides. Antidepressant medications were more frequently detected in suicides, whereas cocaine and ethanol were more frequent in accidents. However, autopsy findings should be weighed in the context of the entire evaluation along with other circumstantial and investigative findings. In unwitnessed deaths where additional information is unavailable or discrepant, the most appropriate manner of death usually is undetermined.

Effect of engineered safety features on the risk of hypothetical LMFBR accidents

International Nuclear Information System (INIS)

Cybulskis, P.

1978-01-01

The risks of hypothetical core-disruptive accidents in liquid-metal-cooled fast breeder reactors which involve meltthrough of the reactor vessel are compared for two plant designs: one design without specific provisions to accommodate such an accident and the other design with an ex-vessel core catcher and a cvity hot liner. The approach to risk analysis used is that developed in the Reactor Safety Study (WASH-1400). Since the probability of occurrence of such an event has not been evaluated, however, insight into the potential risk is gained only on a relative basis. The principal conclusions of this study are: (1) adding a core catcher--hot liner reduces the probabilty of accidents having major consequences; (2) the degree to which hot liner--core catcher systems can reduce the risk of melt-through accidents is limited by the failure probability of these systems; (3) fractional radioactive releases to the environment in the liquid-metal-cooled fast breeder reactor accidents considered are comparable to those from the light-water reactors evaluated in WASH-1400; (4) since sodium--concrete reactions are a dominant driving force during the accident, the integrity of the cavity liner is as important as the function of the core catcher; (5) there may be other accidents or paths to radioactive releases that are not affected by the addition of a hot liner--core catcher

Impact of the filtered venting system design upon the total radioactive release in case of a severe accident and a comparison of European requirements

International Nuclear Information System (INIS)

Cederqvist, H.; Elisson, K.; Loewenhielm, G.; Appelgren, E.

1991-01-01

Filtered containment venting systems have been introduced in several nuclear power plants in Europe. The objective is to relieve the containment overpressure in a controlled way during a severe accident involving core-melt. The release of fission products when operating the venting system has been compared to that resulting from diffuse leakage from the containment. The conclusion is that the diffuse leakage of gaseous and particulate species can not be neglected in comparison to that resulting from operating the filtered containment venting system. Representative European requirements related to filtered containment venting have been analyzed and compared

Release of gases and their influence on containment integrity during a hypothetical meltdown accident

International Nuclear Information System (INIS)

Hassmann, K.; Reimann, M.

1981-01-01

The sequence of a hypothetical core melt down accident has been subdivided into four phases. Heating up of the core until failure of the core support structure is the first phase. It starts at a certain water level in the reactor pressure vessel (RPV) and ends with the failure of the grid plate. The second phase is characterized by the evaporation of the water in the lower plenum of the RPV. The second phase lasts until a molten core debris is formed. The third phase is concerned with the heating up of the pressure vessel after formation of a molten pool in the lower plenum of the RPV. After pressure vessel failure, the molten corium will interact in the fourth phase with the concrete structure beneath the pressure vessel. In this paper the gas release during all four accident phases and the resulting pressure-time history within the containment of a German standard PWR is given, taking into account violent combustion of hydrogen. In particular, the differences caused by dsestruction of concrete with silicious and with calcareous aggregates has been analyzed. The basis for the results in the 4th phase is the WECHSL code. Long term containment calculations have been performed with the COCMEL-code

Modelling of fission product release behavior from HTR spherical fuel elements under accident conditions

International Nuclear Information System (INIS)

Verfondern, K.; Mueller, D.

1991-01-01

Computer codes for modelling the fission product release behavior of spherical fuel elements for High Temperature Reactors (HTR) have been developed for the purpose of being used in risk analyses for HTRs. An important part of the validation and verification procedure for these calculation models is the theoretical investigation of accident simulation experiments which have been conducted in the KueFA test facility in the Hot Cells at KFA. The paper gives a presentation of the basic modeling and the calculational results of fission product release from modern German HTR fuel elements in the temperature range 1600-1800 deg. C using the TRISO coated particle failure model PANAMA and the diffusion model FRESCO. Measurements of the transient release behavior for cesium and strontium and of their concentration profiles after heating have provided informations about diffusion data in the important retention barriers of the fuel: silicon carbide and matrix graphite. It could be shown that the diffusion coefficients of both cesium and strontium in silicon carbide can significantly be reduced using a factor in the range of 0.02 - 0.15 compared to older HTR fuel. Also in the development of fuel element graphite, a tendency towards lower diffusion coefficients for both nuclides can be derived. Special heating tests focussing on the fission gases and iodine release from the matrix contamination have been evaluated to derive corresponding effective diffusion data for iodine in fuel element graphite which are more realistic than the iodine transport data used so far. Finally, a prediction of krypton and cesium release from spherical fuel elements under heating conditions will be given for fuel elements which at present are irradiated in the FRJ2, Juelich, and which are intended to be heated at 1600/1800 deg. C in the KueFA furnace in near future. (author). 7 refs, 11 figs

Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers

Directory of Open Access Journals (Sweden)

Luiz Almeida da Silva

2013-09-01

Full Text Available OBJECTIVE: to investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. METHOD: correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. RESULT: 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. CONCLUSION: motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

An epidemiologic survey of road traffic accidents in Iran: analysis of driver-related factors.

Science.gov (United States)

Moafian, Ghasem; Aghabeigi, Mohammad-Reza; Heydari, Seyed Taghi; Hoseinzadeh, Amin; Lankarani, Kamran Bagheri; Sarikhani, Yaser

2013-01-01

Road traffic accident (RTA) and its related injuries contribute to a significant portion of the burden of diseases in Iran. This paper explores the association between driver-related factors and RTA in the country. This cross-sectional study was conducted in Iran and all data regarding RTAs from March 20, 2010 to June 10, 2010 were obtained from the Traffic Police Department. We included 538 588 RTA records, which were classified to control for the main confounders: accident type, final cause of accident, time of accident and driver-related factors. Driver-related factors included sex, educational level, license type, type of injury, duration between accident and getting the driving license and driver's error type. A total of 538 588 drivers (91.83% male, sex ratio of almost 13:1) were involved in the RTAs. Among them 423 932 (78.71%) were uninjured; 224 818 (41.74%) had a diploma degree. Grade 2 driving license represented the highest proportion of all driving licenses (290 811, 54.00%). The greatest number of accidents took place at 12:00-13:59 (75 024, 13.93%). The proportion of drivers involved in RTAs decreased from 15.90% in the first year of getting a driving license to 3.13% after 10 years'of driving experience. Neglect of regulations was the commonest cause of traffic crashes (345 589, 64.17%). Non-observance of priority and inattention to the front were the most frequent final causes of death (138 175, 25.66% and 129 352, 24.02%, respectively). We found significant association between type of accident and sex, education, license type, time of accident, final cause of accident, driver's error as well as duration between accident and getting the driving license (all P less than 0.001). Our results will improve the traffic law enforcement measures, which will change inappropriate behavior of drivers and protect the least experienced road users.

Nuclear fuel cycle facility accident analysis handbook

International Nuclear Information System (INIS)

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

1988-05-01

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

Work-related accidents and occupational diseases in veterinarians and their staff.

Science.gov (United States)

Nienhaus, Albert; Skudlik, Christoph; Seidler, Andreas

2005-04-01

We assessed the occupational hazards in veterinary practice by analysing accident insurance data in order to stimulate strategies to prevent occupational accidents and diseases in veterinarians and their staff. Approximately 10,000 veterinary practices comprising about 27,500 veterinarians and their staff are covered by the Institution of Statutory Accident Insurance of the Health and Welfare Service (BGW). Each year about 2,000 accident and occupational disease claims are filed by these veterinarians and their staff. The claims for the 5-year period from 1998 to 2002 are analysed in this paper. For 2002, the incidence rate for accidents in the workplace was 105.4 per 1,000 full-time workers, a rate 2.9-times higher than for general practitioners of human medicine. When only severe accidents resulting in a loss of work time of more than 3 days were analysed, the relative risk increased to 9.2. Approximately 66% of the reported accidents are due to scratches, bites, or kicks from animals. Claims of occupational disease are filed 2.7-times more often by veterinarians and their staff than by general practitioners and their staff. The occupational diseases filed most often concern the skin (39%), followed by allergic respiratory diseases (30.5%), and infectious diseases (19.1%). Prevention strategies for veterinarians should focus on accidents caused by animals. The prevention of occupational diseases should focus on skin diseases, respiratory disease, and infections.

Theoretical investigations of the fission product release out of the core of a high temperature reactor during hypothetical heat up accidents as example of caesium

International Nuclear Information System (INIS)

Batalas, T.A.; Iniotakis, N.; Decken, C.B. von der.

1986-03-01

The investigation has been performed by means of a physical model, taking into account the micro- and macro-structures of the pyrolytical and graphitical reactor components as well as renouncing an introduction of effective diffusion coefficients by the description of the fission products transport through the coated particle layers and the fuel elements and renouncing an assumption of the spontaneously adsorption-desorption equilibrium on the surface of the fuel elements. The solving method and the respective computer codes were also developed. In addition the theoretically calculated and the experimentally determined results regarding the caesium release from single coated particles as well as fuel elements at accident temperatures were compared. Finally the caesium release from the core of the PNP-500 reactor during a heat up accident has been estimated and discussed. (orig./HP) [de

Instrumentation Performance during the TMI-2 Accident

International Nuclear Information System (INIS)

Rempe, Joy L.; Knudson, Darrell L.

2013-06-01

The accident at the Three Mile Island Unit 2 (TMI- 2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focused upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this paper. As noted within this paper, several techniques were invoked in the TMI-2 post-accident program to evaluate sensor survivability status and data qualification, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this paper provides recommendations related to sensor survivability and the data evaluation process that could be implemented in upcoming Fukushima Daiichi recovery efforts. (authors)

Urban violence is the biggest cause of fatal work-related accidents in Brazil

OpenAIRE

Cordeiro, Ricardo; Luz, Verônica Gronau; Hennington, Élida Azevedo; Martins, Ana Cláudia Alves; Tófoli, Luís Fernando

2017-01-01

ABSTRACT OBJECTIVE To quantify the occurrence of deaths directly associated with urban violence among fatal work-related accidents. METHODS Verbal autopsies were performed with the relatives and coworkers of residents of Campinas, state of São Paulo, Brazil, who died from external causes in 2015. We have also analyzed police reports and reports of the Legal Medical Institute related to these deaths. RESULTS We have identified 82 fatal work-related accidents in Campinas in 2015, of which 25...

The Chernobyl reactor accident source term: Development of a consensus view

International Nuclear Information System (INIS)

Guntay, S.; Powers, D.A.; Devell, L.

1997-01-01

In August 1986, scientists from the former Soviet Union provided the nuclear safety community with an impressively detailed account of what was then known about the Chernobyl accident. This included assessments of the magnitudes, rates, and compositions of radionuclide releases during the ten days following initiation of the accident. A summary report based on the Soviet report, the oral presentations, and the discussions with scientists from various countries was issued by the International Atomic Energy Agency shortly thereafter. Ten years have elapsed since the reactor accident at Chernobyl. A great deal more data is now available concerning the events, phenomena, and processes that took place. The purpose of this document is to examine what is known about the radioactive materials released during the accident. The accident was peculiar in the sense that radioactive materials were released, at least initially, in an exceptionally energetic plume and were transported far from the reactor site. Release of radioactivity from the plant continued for about ten days. A number of more recent publications and results from scientists in Russia and elsewhere have significantly improved our understanding of the Chernobyl source term. Because of the special features of the reactor design and the pecularities of the Chernobyl accident, the source term for the Chernobyl accident is of limited applicability of the safety analysis of other types of reactors

A methodology for the transfer of probabilities between accident severity categories

International Nuclear Information System (INIS)

Whitlow, J.D.; Neuhauser, K.S.

1992-01-01

Evaluation of the radiological risks of accidents involving vehicles transporting radioactive materials requires consideration of both accident probability and consequences. The probability that an accident will occur may be estimated from historical accident data for the given mode of transport. In addition to an overall accident rate, information regarding accident severity and the resulting package environments across the range of all credible accidents is needed to determine the potential for a release of radioactive material from the package or for an increase in direct radiation from the package caused by damage to packaging shielding. This information is usually obtained from a variety of sources such as historical data, experimental data, analyses of accident and package environments, and expert opinion. The consequences of an accident depend on a number of factors including the type, quantity, and physical form of radioactive material being transported; the response of the package to accident environments; the fraction of material released from the package; and the dispersion of any released material. One approach for the classification and treatment of transportation accidents in risk analysis divides the complete range of critical accident environments resulting from all credible accidents into some number of accident-severity categories. The types of accident environments that a package may be subjected to in transportation are often classified into the following five groups: impact, fire, crush, puncture, and immersion. A open-quotes criticalclose quotes accident environment is one of a type that could present a plausible threat to a package. Each severity category represents a portion of all credible accidents, and the total of all severity categories covers the complete range of critical accident environments. This approach is used in the risk assessment codes RADTRAN (Neuhauser and Kanipe 1992) and INTERTRAN (Ericsson and Elert 1983)

New Technologies for Reducing Aviation Weather-Related Accidents

Science.gov (United States)

Stough, H. Paul, III; Watson, James F., III; Jarrell, Michael A.

2006-01-01

The National Aeronautics and Space Administration (NASA) has developed technologies to reduce aviation weather-related accidents. New technologies are presented for data-link and display of weather information to aircraft in flight, for detection of turbulence ahead of aircraft in flight, and for automated insitu reporting of atmospheric conditions from aircraft.

Aerial spraying to capture released radioactivity from NPP in a severe accident

International Nuclear Information System (INIS)

Younus, Irfan; Yim, Man Sung; Medard, Thiphaine

2016-01-01

The proposed strategy in this paper is the use of aqueous spray (water/foam) mixed with suitable chemical additives to capture, dissolve and stabilize the radioactive gases and aerosol particles released from leaked reactor containment and auxiliary building. The spray system can be approached to the leaked reactor building through the use of a truck with high rising cranes, unmanned aerial vehicles (UAVs, such as helicopters), aerostats, or by installing fixed piping structure around the containment building depending on the accident situation. Laboratory-scale experimental system was setup to examine the performance of such systems. The alkaline water (aqueous NaOH.Na_2S_2O_3) and foam-based spray material (sodium lauryl sulphate) were used to examine capture efficiency of gaseous iodine and aerosol particles. The gaseous iodine and aerosol removal efficiency of foam-based spray is higher when compared with alkaline water-based spray. 2. The nozzle producing full cone spray provides the better removal efficiency than nozzle producing hollow cone spray patterns.

Application of activity theory to analysis of human-related accidents: Method and case studies

International Nuclear Information System (INIS)

Yoon, Young Sik; Ham, Dong-Han; Yoon, Wan Chul

2016-01-01

This study proposes a new approach to human-related accident analysis based on activity theory. Most of the existing methods seem to be insufficient for comprehensive analysis of human activity-related contextual aspects of accidents when investigating the causes of human errors. Additionally, they identify causal factors and their interrelationships with a weak theoretical basis. We argue that activity theory offers useful concepts and insights to supplement existing methods. The proposed approach gives holistic contextual backgrounds for understanding and diagnosing human-related accidents. It also helps identify and organise causal factors in a consistent, systematic way. Two case studies in Korean nuclear power plants are presented to demonstrate the applicability of the proposed method. Human Factors Analysis and Classification System (HFACS) was also applied to the case studies. The results of using HFACS were then compared with those of using the proposed method. These case studies showed that the proposed approach could produce a meaningful set of human activity-related contextual factors, which cannot easily be obtained by using existing methods. It can be especially effective when analysts think it is important to diagnose accident situations with human activity-related contextual factors derived from a theoretically sound model and to identify accident-related contextual factors systematically. - Highlights: • This study proposes a new method for analysing human-related accidents. • The method was developed based on activity theory. • The concept of activity system model and contradiction was used in the method. • Two case studies in nuclear power plants are presented. • The method is helpful to consider causal factors systematically and comprehensively.

US Department of Energy Chernobyl accident bibliography

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R A; Mahaffey, J A; Carr, F Jr

1992-04-01

This bibliography has been prepared by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) Office of Health and Environmental Research to provide bibliographic information in a usable format for research studies relating to the Chernobyl nuclear accident that occurred in the Ukrainian Republic, USSR in 1986. This report is a product of the Chernobyl Database Management project. The purpose of this project is to produce and maintain an information system that is the official United States repository for information related to the accident. Two related products prepared for this project are the Chernobyl Bibliographic Search System (ChernoLit{trademark}) and the Chernobyl Radiological Measurements Information System (ChernoDat). This report supersedes the original release of Chernobyl Bibliography (Carr and Mahaffey, 1989). The original report included about 2200 references. Over 4500 references and an index of authors and editors are included in this report.

US Department of Energy Chernobyl accident bibliography

International Nuclear Information System (INIS)

Kennedy, R.A.; Mahaffey, J.A.; Carr, F. Jr.

1992-04-01

This bibliography has been prepared by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) Office of Health and Environmental Research to provide bibliographic information in a usable format for research studies relating to the Chernobyl nuclear accident that occurred in the Ukrainian Republic, USSR in 1986. This report is a product of the Chernobyl Database Management project. The purpose of this project is to produce and maintain an information system that is the official United States repository for information related to the accident. Two related products prepared for this project are the Chernobyl Bibliographic Search System (ChernoLit trademark) and the Chernobyl Radiological Measurements Information System (ChernoDat). This report supersedes the original release of Chernobyl Bibliography (Carr and Mahaffey, 1989). The original report included about 2200 references. Over 4500 references and an index of authors and editors are included in this report

Exploring Environmental Effects of Accidents During Marine Transport of Dangerous Goods by Use of Accident Descriptions

DEFF Research Database (Denmark)

Rømer, Hans Gottberg; Haastrup, P.; Petersen, H J Styhr

1996-01-01

On the basis of 1776 descriptions of water transport accidents involving dangerous goods, environmental problems in connection with releases of this kind are described and discussed. It was found that most detailed descriptions of environmental consequences concerned oil accidents, although most...... longer than broad. Gravity scales used to describe and evaluate environmental consequences were discussed....

Relationship between non-standard work arrangements and work-related accident absence in Belgium.

Science.gov (United States)

Alali, Hanan; Braeckman, Lutgart; Van Hecke, Tanja; De Clercq, Bart; Janssens, Heidi; Wahab, Magd Abdel

2017-03-28

The main objective of this study is to examine the relationship between indicators of non-standard work arrangements, including precarious contract, long working hours, multiple jobs, shift work, and work-related accident absence, using a representative Belgian sample and considering several socio-demographic and work characteristics. This study was based on the data of the fifth European Working Conditions Survey (EWCS). For the analysis, the sample was restricted to 3343 respondents from Belgium who were all employed workers. The associations between non-standard work arrangements and work-related accident absence were studied with multivariate logistic regression modeling techniques while adjusting for several confounders. During the last 12 months, about 11.7% of workers were absent from work because of work-related accident. A multivariate regression model showed an increased injury risk for those performing shift work (OR 1.546, 95% CI 1.074-2.224). The relationship between contract type and occupational injuries was not significant (OR 1.163, 95% CI 0.739-1.831). Furthermore, no statistically significant differences were observed for those performing long working hours (OR 1.217, 95% CI 0.638-2.321) and those performing multiple jobs (OR 1.361, 95% CI 0.827-2.240) in relation to work-related accident absence. Those who rated their health as bad, low educated workers, workers from the construction sector, and those exposed to biomechanical exposure (BM) were more frequent victims of work-related accident absence. No significant gender difference was observed. Indicators of non-standard work arrangements under this study, except shift work, were not significantly associated with work-related accident absence. To reduce the burden of occupational injuries, not only risk reduction strategies and interventions are needed but also policy efforts are to be undertaken to limit shift work. In general, preventive measures and more training on the job are needed to

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

Science.gov (United States)

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

2004-01-01

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

Accident patterns for construction-related workers: a cluster analysis

Science.gov (United States)

Liao, Chia-Wen; Tyan, Yaw-Yauan

2012-01-01

The construction industry has been identified as one of the most hazardous industries. The risk of constructionrelated workers is far greater than that in a manufacturing based industry. However, some steps can be taken to reduce worker risk through effective injury prevention strategies. In this article, k-means clustering methodology is employed in specifying the factors related to different worker types and in identifying the patterns of industrial occupational accidents. Accident reports during the period 1998 to 2008 are extracted from case reports of the Northern Region Inspection Office of the Council of Labor Affairs of Taiwan. The results show that the cluster analysis can indicate some patterns of occupational injuries in the construction industry. Inspection plans should be proposed according to the type of construction-related workers. The findings provide a direction for more effective inspection strategies and injury prevention programs.

The role of chemistry in nuclear accidents

International Nuclear Information System (INIS)

Johnson, C.E.; Johnson, I.

1986-01-01

An accurate description of the chemical state of fission products is required for quick response in assessing the impact of nuclide release during a nuclear accident. The chemical state of the fission products is certain to change in response to their local environment. More specifically, fission products released from fuel will change their composition on contact with high-temperature steam, and these changes will determine their behavior with regard to either transport, deposition, aerosol formation, or reaction with structural components. The local oxygen potential is a key parameter in establishing the chemical state of the fission products and their release and transport mechanisms. Knowledge of the relationship of this parameter and thermal hydraulics is needed for prediction of fission product behavior in degraded core accidents. The behavior of key fission products in various stages of an accident, based on experimental results and appropriate calculations founded on fundamental thermodynamic information, will be discussed

Investigation of evaluation method for marine radiological impact during an accident

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-08-15

In 2012, JNES carried out to investigate the measurement information of radionuclide released to the ocean at Fukushima Daiichi NPP accident, the foreign regulation for marine radiological impact, and the evaluation method for release and diffusion to the ocean at the accident inside and outside Japan. (author)

Traffic crash accidents in Tehran, Iran: Its relation with circadian rhythm of sleepiness.

Science.gov (United States)

Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Moradinia, Mohsen; Aminian, Omid; Esmaili, Alireza

2015-01-01

Road traffic accidents are one of main problems in Iran. Multiple factors cause traffic accidents and the most important one is sleepiness. This factor, however, is given less attention in our country. Road traffic accidents relevant to sleepiness are studied. In this cross-sectional study, all road traffic accidents relevant to sleepiness, which were reported by police, were studied in Tehran province in 2009. The risk of road traffic accidents due to sleepiness was increased by more than sevenfold (odds ratio = 7.33) in low alertness hours (0:00-6:00) compared to other time of day. The risk of road traffic accidents due to sleepiness was decreased by 0.15-fold (odds ratio = 0.15) in hours with maximum of alertness (18:00-22:00) of circadian rhythm compared to other time of day. The occurrence of road traffic accidents due to sleepiness has significant statistical relations with driving during lowest point of alertness of circadian rhythm.

Relative Release-to-Birth Indicators for Investigating TRISO Fuel Fission Gas Release Models

International Nuclear Information System (INIS)

Harp, Jason M.; Hawari, Ayman I.

2008-01-01

TRISO microsphere fuel is the fundamental fuel unit for Very High Temperature Reactors (VHTR). A single TRISO particle consists of an inner kernel of uranium dioxide or uranium oxycarbide surrounded by layers of pyrolytic carbon and silicon carbide. If the silicon carbide layer fails, fission products, especially the noble fission gases Kr and Xe, will begin to escape the failed particle. The release of fission gas is usually quantified by measuring the ratio of the released activity (R) to the original birth activity (B), which is designated as the R/B ratio. In this work, relative Release-to-Birth indicators (I) are proposed as a technique for interpreting the results of TRISO irradiation experiments. By implementing a relative metric, it is possible to reduce the sensitivity of the indicators to instrumental uncertainties and variations in experimental conditions. As an example, relative R/B indicators are applied to the interpretation of representative data from the Advanced Gas Reactor-1 TRISO fuel experiment that is currently taking place at the Advanced Test Reactor of Idaho National Laboratory. It is shown that the comparison of measured to predicted relative R/B indicators (I) gives insight into the physics of release and helps validate release models. Different trends displayed by the indicators are related to the mechanisms of fission gas release such as diffusion and recoil. The current analysis shows evidence for separate diffusion coefficients for Kr and Xe and supports the need to account for recoil release. (authors)

Critical evaluation of the experiments and mathematical models for the determination of fission product release from the spherical fuel elements in cases of core heating accidents in modular HTR's

International Nuclear Information System (INIS)

Bailly, H.W.

1987-01-01

In this work, the thermal behaviour of modular reactors in cases of core heating accidents and the physical phenomena relevant for a release of radioactive materials from HTR fuel elements are explained as far as is necessary for understanding the work. The present mathematical models by which the release of radioactive materials from HTR fuel elements due to diffusion or breaking particles in cases of core heating accidents are also described, examined and evaluated with regard to their applicability to module reactors. The experiments used to verify the mathematical models are also evaluated. The mathematical models are in nearly all cases computer programs, which describe the complicated process of releasing radioactive materials quantitative mathematically. One should point out that these models are constantly being developed further, in line with the increasing amount of knowledge. To conclude the work, proposals are made for improving the certainty of information from experiments and mathematical models to determine the release behaviour of modular reactors. (orig./GL) [de

French policy for managing the post-accident phase of a nuclear accident.

Science.gov (United States)

Gallay, F; Godet, J L; Niel, J C

2015-06-01

In 2005, at the request of the French Government, the Nuclear Safety Authority (ASN) established a Steering Committee for the Management of the Post-Accident Phase of a Nuclear Accident or a Radiological Emergency, with the objective of establishing a policy framework. Under the supervision of ASN, this Committee, involving several tens of experts from different backgrounds (e.g. relevant ministerial offices, expert agencies, local information commissions around nuclear installations, non-governmental organisations, elected officials, licensees, and international experts), developed a number of recommendations over a 7-year period. First published in November 2012, these recommendations cover the immediate post-emergency situation, and the transition and longer-term periods of the post-accident phase in the case of medium-scale nuclear accidents causing short-term radioactive release (less than 24 h) that might occur at French nuclear facilities. They also apply to actions to be undertaken in the event of accidents during the transportation of radioactive materials. These recommendations are an important first step in preparation for the management of a post-accident situation in France in the case of a nuclear accident. © The Chartered Institution of Building Services Engineers 2014.

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

International Nuclear Information System (INIS)

Wyss, G.D.; Camp, A.L.; Miller, L.A.; Dingman, S.E.; Kunsman, D.M.; Medford, G.T.

1990-06-01

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

Severe accident considerations for modern KWU-PWR plants

International Nuclear Information System (INIS)

Eyink, J.

1987-01-01

In assumption of severe accident on modern KWU-PWR plants the author discusses on the: selection of core meltdown sequences, course of the accident, containment behaviour and source terms for fission products release to the environment

Facility accident considerations in the US Department of Energy Waste Management Program

International Nuclear Information System (INIS)

Mueller, C.

1994-01-01

A principal consideration in developing waste management strategies is the relative importance of Potential radiological and hazardous releases to the environment during postulated facility accidents with respect to protection of human health and the environment. The Office of Environmental Management (EM) within the US Department of Energy (DOE) is currently formulating an integrated national program to manage the treatment, storage, and disposal of existing and future wastes at DOE sites. As part of this process, a Programmatic Environmental impact Statement (PEIS) is being prepared to evaluate different waste management alternatives. This paper reviews analyses that have been Performed to characterize, screen, and develop source terms for accidents that may occur in facilities used to store and treat the waste streams considered in these alternatives. Preliminary results of these analyses are discussed with respect to the comparative potential for significant releases due to accidents affecting various treatment processes and facility configurations. Key assumptions and sensitivities are described

Identification and assessment of containment and release management strategies

International Nuclear Information System (INIS)

Lehner, J.R.; Lin, C.C.; Neogy, P.

1990-01-01

Brookhaven National Laboratory, under the auspices of the U.S. Nuclear Regulatory Commission, is investigating accident management strategies which could help preserve containment integrity or minimize releases during a severe accident. The objective is to make use of existing plant systems and equipment in innovative ways to reduce the likelihood of containment failure or to mitigate the release of fission products to the environment if failure cannot be prevented. Many of these strategies would be implemented during the later stages of a severe accident (i.e., after vessel breach) and sizeable uncertainties exist regarding some of the phenomena involved. A majority of the strategies identified go well beyond existing procedures and often depend on the specific containment type. Strategies for all of the five different containments used in the U.S. are being considered: BWR Mark I, Mark II, and Mark III, as well as PWR ice condenser and large dry containments. Accident management strategies related to the in-vessel phase of a severe core melt accident are being dealt with under another NRC program. For each containment type the most likely challenges are identified and existing emergency guidelines and procedures are reviewed as to how they address these challenges

Review of specific radiological accident considerations

International Nuclear Information System (INIS)

Elder, J.

1984-01-01

Specific points of guidance provided in the forthcoming document A Guide to Radiological Accident Considerations for Siting and Design of Nonreactor Nuclear Facilities are discussed. Of these, the following are considered of particular interest to analysts of hypothetical accidents: onsite dose limits; population dose, public health effects, and environmental contamination as accident consequences which should be addressed; risk analysis; natural phenomena as accident initiators; recommended dose models; multiple organ equivalent dose; and recommended methods and parameters for source terms and release amount calculations. Comments are being invited on this document, which is undergoing rewrite after the first stage of peer review

Evaluation of strategies for severe accident prevention and mitigation

International Nuclear Information System (INIS)

Tokarz, R.

1989-01-01

The NRC is planning to establish regulatory oversight on severe accident management capability in the US nuclear reactor industry. Accident management includes certain preparatory and recovery measures that can be taken by the plant operating and technical personnel to prevent or mitigate the consequences of a severe accident. Following an initiating event, accident management strategies include measures to (1) prevent core damage, (2) arrest the core damage if it begins and retain the core inside the vessel, (3) maintain containment integrity if the vessel is breached, and (4) minimize offsite releases. Objectives of the NRC Severe Accident Management Program are to assure that technically sound strategies are identified and guidance to implement these strategies is provided to utilities. This paper will describe work performed to date by Pacific Northwest Laboratory (PNL) and Battelle Memorial Institute (BMI) relative to severe accident strategy evaluation, as well as work to be performed and expected results. Working with Brookhaven National Laboratory, PNL evaluated a series of NRC suggested accident management strategies. The evaluation of these strategies was divided between PNL and Brookhaven National Laboratory and a similar paper will be presented by Brookhaven regarding their strategy evaluation. This paper will stress the overall safety issues related to the research and emphasize the strategies that are applicable to major safety issues. The relationship of these research activities to other projects is discussed, as well as planning for future changes in the direction of work to be undertaken

[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...

Atmospheric dispersion calculation for posturated accident of nuclear facilities and the computer code: PANDA

International Nuclear Information System (INIS)

Kitahara, Yoshihisa; Kishimoto, Yoichiro; Narita, Osamu; Shinohara, Kunihiko

1979-01-01

Several Calculation methods for relative concentration (X/Q) and relative cloud-gamma dose (D/Q) of the radioactive materials released from nuclear facilities by posturated accident are presented. The procedure has been formulated as a Computer program PANDA and the usage is explained. (author)

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)

Perspectives on the economic risks of LWR accidents

International Nuclear Information System (INIS)

Ritchie, L.T.; Burke, R.P.

1986-01-01

Models which can be used for the analysis of the economic risks from events which may occur during LWR operation have been developed. The models include capabilities to estimate both onsite and offsite costs of LWR events ranging from routine plant forced outages to severe core-melt accidents resulting in large releases of radioactive material to the environment. The economic consequence models have been applied in studies of the economic risks from the operation of US LWR plants. The results of the analyses provide some important perspectives regarding the economic risks of LWR accidents. The analyses indicate that economic risks, in contrast to public health risks, are dominated by the onsite costs of relatively high-frequency forced outage events. Even for severe (e.g., core-melt) accidents, expected offsite costs are less than expected onsite costs for a typical US plant

[Epidemiology of work-related accidents in the Lazio Region of Italy].

Science.gov (United States)

Marchetti, Aurora; Mantovani, Jessica; Di Lallo, D; Di Napoli, A; Guasticchi, Gabriella

2011-01-01

Prevention of work-related accidents requires an in-depth epidemiological assessment of the issue. In Italy the most used databases are from the national insurance (INAIL) and research (ISPESL) institutes. However, these data are only available several years after the time of accident. To describe the characteristics of accidents and evaluate factors potentially associated with hospitalization using the Information System of Hospital Emergency Departments (SIES). We analyzed 51.705 Emergency Department (ED) work-related accident admissions in the Lazio Region of Italy in 2008 among workers aged 16-65 years. Information on socio-demographics, diagnosis, triage codes, and outcome of ED admissions were gathered. We performed a logistic regression model to estimate association between these factors and risk of hospitalization after ED admission. The subjects' mean age was 39.1 (SD 11.0); 71.5% woere men, 12.7% were foreigners, 5.9% arrived by ambulance, 4.5% with triage red/yellow tags, 2.7% were hospitalized. Diagnosis was trauma in 85.1%, orthopaedic lesions in 8.3%. We found a higher risk of hospitalization in subjects with: one year of age increase (OR=1.02; 95% CIs: 1.01-1.03), males (OR=1.68; 95% CIs: 1.44-1.97), foreigners coming from countries with high emigration rates (OR=1.55; 95% CIs: 1.31-1.82), ED triage red/yellow tags (OR=84.47; 95% CIs: 47.06-151.60). It was confirmed that data fr-om an emergency health care information system can be a useful complement to information gathered by national insurance and research institutes, thus resolving the limit posed by the delay in availability for analysis of these data after the occurrence of accidents. We also identified some factors potentially associated with more serious accidents, which constitute a basis for planning and implementing specific public health preventive interventions.

Drug abuse-related accidents leading to emergency department visits at two medical centers.

Science.gov (United States)

Chen, Isaac Chun-Jen; Hung, Dong-Zong; Hsu, Chi-Ho; Wu, Ming-Ling; Deng, Jou-Fang; Chang, Chin-Yu; Shih, Hsin-Chin; Liu, Chen-Chi; Wang, Chien-Ying; Wen, Yi-Szu; Wu, Jackson Jer-Kan; Huang, Mu-Shun; Yang, Chen-Chang

2012-05-01

Drug abuse is becoming more prevalent in Taiwan, as evidenced by increasing reports of drug trafficking and drug abuse-related criminal activity, and the wide use of more contemporary illicit drugs. Consequently, drug abuse-related accidents are also expected to occur with greater frequency. However, no study has yet specifically evaluated the prevalence, pattern, and outcomes of drug abuse-related accidents among patients visiting emergency departments (EDs) in Taiwan. We conducted an ambidirectional study with patients who visited the EDs of Taipei Veterans General Hospital (TVGH) and China Medical University Hospital (CMUH) due to drug abuse-related accidents from January 2007 through September 2009. Information on the patients' baseline characteristics and clinical outcomes was collected and analyzed. During the study period, a total of 166 patients visited the EDs of one of the two study hospitals due to drug abuse-related accidents. This yielded a prevalence of drug abuse of 0.1% among all patients visiting the ED due to accident and/or trauma. Fifty-six out of the 166 patients visited the ED at TVGH, most patients being between 21 and 40 years old. Opioids (41.1%) were the drugs most commonly abused by the patients, followed by benzodiazepines (32.1%). More than two-thirds of the patients (n=38, 67.9%) required hospitalization, and three patients died (5.4%). In contrast, 110 patients with drug abuse-related accidents visited the ED at CMUH during the study period. Most of these subjects had abused benzodiazepines (69.1%), were between 21 and 40 years old, and were female. Fewer than one-fifth of the patients (n=19, 17.3%) required hospitalization, with no deaths reported. There were significant between-hospital differences in terms of patient gender, drugs of choice, injury mechanisms, method and time of the ED visit, triage levels, and need for hospitalization. Although the prevalence of drug abuse-related accidents was low, and only three patient deaths

Analysis on tank truck accidents involved in road hazardous materials transportation in china.

Science.gov (United States)

Shen, Xiaoyan; Yan, Ying; Li, Xiaonan; Xie, Chenjiang; Wang, Lihua

2014-01-01

Due to the sheer size and capacity of the tanker and the properties of cargo transported in the tank, hazmat tanker accidents are more disastrous than other types of vehicle accidents. The aim of this study was to provide a current survey on the situation of accidents involving tankers transporting hazardous materials in China. Detailed descriptions of 708 tanker accidents associated with hazmat transportation in China from 2004 to 2011 were analyzed to identify causes, location, types, time of occurrence, hazard class for materials involved, consequences, and the corresponding probability. Hazmat tanker accidents mainly occurred in eastern (38.1%) and southwest China (12.3%). The most frequent hazmat tanker accidents involved classes 2, 3, and 8. The predominant accident types were rollover (29.10%), run-off-the-road (16.67%), and rear-end collisions (13.28%), with a high likelihood of a large spill occurring. About 55.93% of the accidents occurred on freeways and class 1 roads, with the spill percentage reaching 75.00% and the proportion of spills that occurred in the total accidents amounting to 77.82%, of which 61.72% are considered large spills. The month with the highest accident probability was July (12.29%), and most crashes occurred during the early morning (4:00-6:00 a.m.) and midday (10:00 a.m.-12:00 p.m.) hours, 19.63% versus 16.10%. Human-related errors (73.8%) and vehicle-related defects (19.6%) were the primary reasons for hazmat tanker crashes. The most common outcomes of a hazmat tanker accident was a spill without further events (55.51%), followed by a release with fire (7.77%), and release with an explosion (2.54%). The safety situation of China's hazmat tanker transportation is grim. Such accidents not only have high spill percentages and consistently large spills but they can also cause serious consequences, such as fires and explosions. Improving the training of drivers and the quality of vehicles, deploying roll stability aids, enhancing

The radiation accident at Institute for Energy Technology Sept. 1982

International Nuclear Information System (INIS)

Berteig, L.; Flatby, J.

1983-01-01

On September 2, 1982 a radiation accident with overexposure of one person happened at the gamma irradiation plant at Institute for Energy Technology, Kjeller, Norway. This person died from the radiation injury 13 days later. In the report reference is made to the work of different groups and bodies in connection with the accident. An analysis of the causes of the accident is given. For admittance control to the irradiation area there were generally two independent door interlock systems, one irradiation source position related and the other radiation related. The latter was dismantled for repair at the time of the accident. A micro-switch failure left the source in an ushielded position, initiated a green light on the control panel and released the interlock system of the door. According to working instructions a mobile radiation monitor should have been checked for proper function and carried by anyone entering the irradiation room. This seems not to have been carried out correctly. The conditions set forth by the Norwegian Institute of Radiation Hygiene for the restarting of the irradiation plant are presented. (RF)

[Characterization of severe acute occupational poisoning accidents related to irritating gases in China between 1989 and 2003].

Science.gov (United States)

Du, Xie-Yi; Zhang, Min; Wang, Huan-Qiang; Li, Tao; Wang, Hong-Fei; Chen, Shu-Yang; Zhang, Shuang; Qin, Jian; Ji, Li-Ying

2006-12-01

To analyze severe acute occupational poisoning accidents related to irritating gases reported in China between 1989 and 2003, and to study the characteristics of severe acute occupational poisoning accidents and provide scientific evidences for prevention and control strategies. The data from the national occupational poisoning case reporting system were analyzed with descriptive methods. (1) There were 92 severe acute occupational poisoning accidents related to asphyxiating gases during 15 years, which showed that there were 14.5 accidents occurred each year. Forty types of chemicals were reported to cause poisoning accidents directly. On average, there were 14.5 persons poisoned and 0.8 persons died of poisoning in each event. The number of death of poisoning reached 7 in most of the severe accidents. Chlorine was the main irritating gas resulting in poisoning accidents according to the number of accidents, cases and death. (1) The severe acute occupational poisoning related to irritating gases are more dangerous than others because of it is involved in more cases in each accident. (2) The accidents have concentricity in the certain types of chemicals, industries and jobs, and should be focused on control. (3) It is important to develop the program about early warning and forecast and the first aid.

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.

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

Research and development strategy on the behavior of containments during severe accidents

International Nuclear Information System (INIS)

Lecomte, C.

1990-06-01

In case of an hypothetical severe accident leading to core melting, the last barrier preventing radionucleide release in the environnment is the containment of the main reactor building. The French research and development programmes aimed at understanding the containment behavior during severe accidents relate to several domains; some of them are: - assessment of hydrogen behavior - corium behavior and coolability - ultimate resistance of the containments and leaktightness - caracterization of filtered venting procedure. All these aspects are covered by code calculations and experimental developments

Examination of a measuring method for fallout radioactivity released by the accident of the Fukushima Dai-ichi NPS. Surface contamination measurement

International Nuclear Information System (INIS)

Yoshii, Taiki; Kawasaki, Satoru

2013-08-01

Radioactive nuclides were released in the atmosphere by the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station in March, 2011, and they are detected on the materials that had no artificial radioactive nuclides before the accident. Confronted with this situation, NISA issued a guideline titled 'A guideline regarding treatment of materials in nuclear facilities considering the influence of fallout released from the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station' on March 30, 2012. Nuclear Regulatory Authority refers to applying the existing bylaw until the time to make decision of the updated bylaw. The guideline shows that after judging whether there is the influence of fallout or not, the conventional clearance and NR systems can be used when there is no influence of fallout. On the other hand, the special treatment is required when it is judged that there is the influence. This report describes a specific example of measuring method to evaluate the influence of fallout, in case of surface contamination. This report focused surface contamination of flat object as target. Preliminary investigation shows that the distribution of surface contamination due to fallout is near to lognormal distribution. Therefore, the sampling measurement can be adopted. The average surface contamination of target is decided from sampling data by using 90% upper confidence limit of Chebyshev inequality. Also, the minimum sampling number is decided. The evaluation of the influence of fallout is judged from the result of surface contamination measurement, weight of target and surface area of target. (author)

Prognostic significance of specific injury patterns in casualties of traffic-related accidents.

Science.gov (United States)

Calosevic, Srdjan; Lovric, Zvonimir

2015-11-01

Fatal triad and ipsilateral dyad are patterns of pedestrian injuries related to significant mortality in traffic-related accidents. The aim of this research was to investigate the correlation between specific injury patterns and fatal outcome in other participants of traffic-related accidents. This was a retrospective study of traffic-related accidents in the broader area of the city of Osijek in a five-year period from 1995 to 1999. Autopsy results from the Institute of Pathology and Forensic Medicine of the Clinical Hospital Centre Osijek were analysed of individuals who died after their accident. The total severity of injuries was measured using the ISS. Logistic regression analysis was used for assessing the correlation between specific injury patterns and an early outcome from the severe injury. There were 213 individuals included in the study: 72 pedestrians and 141 other participants (drivers, assistant drivers, passengers, cyclists and motorcyclists). A total of129 individuals died on the spot and 84 died in the hospital during the first 48h. Femoral and pelvic fracture, fatal triad and both variants of ipsilateral dyad were related to higher ISS values. Ipsilateral fracture of upper and lower extremities (ipsilateral dyad 1) was associated with a 4.59 times higher risk of an immediate fatal outcome in the total sample. In pedestrians, the risk was 5.99 higher, and in other participants, the risk was 4.11 times higher. Specific skeletal injuries and injury patterns are a significant indicator for total injury severity and related poor prognosis for all participants of traffic-related injuries, not only for pedestrians. In this study, the ipsilateral fracture of upper and lower extremity was related to the largest total severity of injuries and the poorest prognosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low level waste shipment accident lessons learned

International Nuclear Information System (INIS)

Rast, D.M.; Rowe, J.G.; Reichel, C.W.

1995-01-01

On October 1, 1994 a shipment of low-level waste from the Fernald Environmental Management Project, Fernald, Ohio, was involved in an accident near Rolla, Missouri. The accident did not result in the release of any radioactive material. The accident did generate important lessons learned primarily in the areas of driver and emergency response communications. The shipment was comprised of an International Standards Organization (ISO) container on a standard flatbed trailer. The accident caused the low-level waste package to separate from the trailer and come to rest on its top in the median. The impact of the container with the pavement and median inflicted relatively minor damage to the container. The damage was not substantial enough to cause failure of container integrity. The success of the package is attributable to the container design and the packaging procedures used at the Fernald Environmental Management Project for low-level waste shipments. Although the container survived the initial wreck, is was nearly breached when the first responders attempted to open the ISO container. Even though the container was clearly marked and the shipment documentation was technically correct, this information did not identify that the ISO container was the primary containment for the waste. The lessons learned from this accident have DOE complex wide applicability. This paper is intended to describe the accident, subsequent emergency response operations, and the lessons learned from this incident

Chernobyl accident. Exposures and effects

International Nuclear Information System (INIS)

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

2000-01-01

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

Application of FFTBM to severe accidents

International Nuclear Information System (INIS)

Prosek, A.; Leskovar, M.

2005-01-01

In Europe an initiative for the reduction of uncertainties in severe accident safety issues was initiated. Generally, the error made in predicting plant behaviour is called uncertainty, while the discrepancies between measured and calculated trends related to experimental facilities are called the accuracy of the prediction. The purpose of the work is to assess the accuracy of the calculations of the severe accident International Standard Problem ISP-46 (Phebus FPT1), performed with two versions of MELCOR 1.8.5 for validation purposes. For the quantitative assessment of calculations the improved fast Fourier transform based method (FFTBM) was used with the capability to calculate time dependent code accuracy. In addition, a new measure for the indication of the time shift between the experimental and the calculated signal was proposed. The quantitative results obtained with FFTBM confirm the qualitative conclusions made during the Jozef Stefan Institute participation in ISP-46. In general good agreement of thermal-hydraulic variables and satisfactory agreement of total releases for most radionuclide classes was obtained. The quantitative FFTBM results showed that for the Phebus FPT1 severe accident experiment the accuracy of thermal-hydraulic variables calculated with the MELCOR severe accident code is close to the accuracy of thermal-hydraulic variables for design basis accident experiments calculated with best-estimate system codes. (author)

A review of criticality accidents

International Nuclear Information System (INIS)

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

1989-03-01

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

Fission product release mechanisms and groupings

International Nuclear Information System (INIS)

Iglesia, F.C.; Brito, A.C.; Liu, Y.

1995-01-01

During CANDU postulated accidents the reactor fuel is estimated to be exposed to a variety of conditions. These conditions are dynamic and, during the course of an accident, the fuel may experience a wide range of temperatures and conditions from highly oxidizing to mildly reducing environments. The exposure of the reactor fuel to these environments and temperatures may affect its stoichiometry and release performance. In this paper a review of the important fission product release mechanisms is presented, the results of three out-of-pile experimental programs are summarized, and fission product release groups, for both oxidizing and reducing conditions are proposed. (author)

Aftermath of the Fukushima Daiichi nuclear accident in March 2011 - Situation review in March 2016

International Nuclear Information System (INIS)

2016-03-01

The first part of this detailed report addresses the consequences of the accident regarding nuclear safety. It proposes a situation review of site damaged installations, of radioactive water management, and of underground water management. It presents and comments lessons learned from this accident for French nuclear installations, gives an overview of researches performed by the IRSN in the field of nuclear safety. The second part addresses health consequences of the accident. It discusses an assessment of epidemiologic studies performed on inhabitants of the Fukushima Prefecture, and comments the situation of workers involved in operations performed in the Fukushima Daiichi nuclear power plant. The third part addresses environmental consequences. It discusses values of radionuclide concentrations in Japanese air five years after the accident, measurements of caesium activities, assessments of contamination of Japanese food products, decontamination actions and waste management, the status of marine contamination in 2015, the evolution of evacuation areas between 2011 and 2016, the first returns and wills to return of evacuated populations, the update of knowledge related to the dispersion and depositions of atmospheric releases of the accident, and the modelling of atmospheric transport and fallouts of releases emitted during the accident. The last part proposes a comparison between the Chernobyl accident and the Fukushima accident in terms of distribution of radioactive depositions within river basins, of knowledge drawn from ecologic studies on fauna and flora performed on the long term in contaminated areas, and of management of forest environments after a nuclear accident

Accident sequences simulated at the Juragua nuclear power plant

International Nuclear Information System (INIS)

Carbajo, J.J.

1998-01-01

Different hypothetical accident sequences have been simulated at Unit 1 of the Juragua nuclear power plant in Cuba, a plant with two VVER-440 V213 units under construction. The computer code MELCOR was employed for these simulations. The sequences simulated are: (1) a design-basis accident (DBA) large loss of coolant accident (LOCA) with the emergency core coolant system (ECCS) on, (2) a station blackout (SBO), (3) a small LOCA (SLOCA) concurrent with SBO, (4) a large LOCA (LLOCA) concurrent with SBO, and (5) a LLOCA concurrent with SBO and with the containment breached at time zero. Timings of important events and source term releases have been calculated for the different sequences analyzed. Under certain weather conditions, the fission products released from the severe accident sequences may travel to southern Florida

Atmospheric transport of radioactive debris to Norway in case of a hypothetical accident related to the recovery of the Russian submarine K-27

International Nuclear Information System (INIS)

Bartnicki, Jerzy; Amundsen, Ingar; Brown, Justin; Hosseini, Ali; Hov, Øystein; Haakenstad, Hilde; Klein, Heiko; Lind, Ole Christian; Salbu, Brit; Szacinski Wendel, Cato C.; Ytre-Eide, Martin Album

2016-01-01

The Russian nuclear submarine K-27 suffered a loss of coolant accident in 1968 and with nuclear fuel in both reactors it was scuttled in 1981 in the outer part of Stepovogo Bay located on the eastern coast of Novaya Zemlya. The inventory of spent nuclear fuel on board the submarine is of concern because it represents a potential source of radioactive contamination of the Kara Sea and a criticality accident with potential for long-range atmospheric transport of radioactive particles cannot be ruled out. To address these concerns and to provide a better basis for evaluating possible radiological impacts of potential releases in case a salvage operation is initiated, we assessed the atmospheric transport of radionuclides and deposition in Norway from a hypothetical criticality accident on board the K-27. To achieve this, a long term (33 years) meteorological database has been prepared and used for selection of the worst case meteorological scenarios for each of three selected locations of the potential accident. Next, the dispersion model SNAP was run with the source term for the worst-case accident scenario and selected meteorological scenarios. The results showed predictions to be very sensitive to the estimation of the source term for the worst-case accident and especially to the sizes and densities of released radioactive particles. The results indicated that a large area of Norway could be affected, but that the deposition in Northern Norway would be considerably higher than in other areas of the country. The simulations showed that deposition from the worst-case scenario of a hypothetical K-27 accident would be at least two orders of magnitude lower than the deposition observed in Norway following the Chernobyl accident. - Highlights: • Long-term meteorological database has been developed for atmospheric dispersion. • Using this database, the worst case meteorological scenarios have been selected. • Mainly northern parts of Norwegian territory will be

The Chernobyl accident, a catastrophe or an eye-opener?

International Nuclear Information System (INIS)

Baarli, J.

1989-01-01

The Chernobyl accident is reviewed as to its cause, the way it was handled locally and the consequenses from released radioactivity. It is emphasized that the exposure from the released radioactivity, as to the effective dose equivalent and the committed dose equivalent is small and comparable with the dose equivalent from natural ionizing radiation near the accident, and only a few per cent of this value at more remote distances. It is concluded that the accident probably has been one of the greatest psychological catastrophes that we so far has experienced, but not so when referring to early deaths or radiation damage directly to individuals

Application of NUREG-1150 methods and results to accident management

International Nuclear Information System (INIS)

Dingman, S.; Sype, T.; Camp, A.; Maloney, K.

1991-01-01

The use of NUREG-1150 and similar probabilistic risk assessments in the Nuclear Regulatory Commission (NRC) and industry risk management programs is discussed. Risk management is more comprehensive than the commonly used term accident management. Accident management includes strategies to prevent vessel breach, mitigate radionuclide releases from the reactor coolant system, and mitigate radionuclide releases to the environment. Risk management also addresses prevention of accident initiators, prevention of core damage, and implementation of effective emergency response procedures. The methods and results produced in NUREG-1150 provide a framework within which current risk management strategies can be evaluated, and future risk management programs can be developed and assessed. Examples of the use of the NUREG-1150 framework for identifying and evaluating risk management options are presented. All phases of risk management are discussed, with particular attention given to the early phases of accidents. Plans and methods for evaluating accident management strategies that have been identified in the NRC accident management program are discussed

Application of NUREG-1150 methods and results to accident management

International Nuclear Information System (INIS)

Dingman, S.; Sype, T.; Camp, A.; Maloney, K.

1990-01-01

The use of NUREG-1150 and similar Probabilistic Risk Assessments in NRC and industry risk management programs is discussed. ''Risk management'' is more comprehensive than the commonly used term ''accident management.'' Accident management includes strategies to prevent vessel breach, mitigate radionuclide releases from the reactor coolant system, and mitigate radionuclide releases to the environment. Risk management also addresses prevention of accident initiators, prevention of core damage, and implementation of effective emergency response procedures. The methods and results produced in NUREG-1150 provide a framework within which current risk management strategies can be evaluated, and future risk management programs can be developed and assessed. Examples of the use of the NUREG-1150 framework for identifying and evaluating risk management options are presented. All phases of risk management are discussed, with particular attention given to the early phases of accidents. Plans and methods for evaluating accident management strategies that have been identified in the NRC accident management program are discussed. 2 refs., 3 figs

Technical bases for estimating fission product behavior during LWR accidents. Technical report

International Nuclear Information System (INIS)

1981-06-01

The objective of this report is to provide the Nuclear Regulatory Commission and the public with a description of the best technical information currently available for estimating the release of radioactive material during postulated reactor accidents, and to identify where gaps exist in our knowledge. This report focuses on those low probability-high consequence accidents involving severe damage to the reactor core and core meltdown that dominate the risk to the public. Furthermore, in this report particular emphasis is placed on the accident behavior of radioactive iodine, as (1) radioiodine is predicted to be a major contributor to public exposure, (2) current regulatory accident analysis procedures focus on iodine, and (3) several technical issues have been raised recently about the magnitude of iodine release. The generation, transport, and attenuation of aerosols were also investigated in some detail to assess their effect on fission product release estimates and to determine the performance of engineered safety features under accident conditions exceeding their design bases

Regulation Plans on Severe Accidents developed by KINS Severe Accident Regulation Preparation TFT

International Nuclear Information System (INIS)

Kim, Kyun Tae; Chung, Ku Young; Na, Han Bee

2016-01-01

Some nuclear power plants in Fukushima Daiichi site had lost their emergency reactor cooling function for long-time so the fuels inside the reactors were molten, and the integrity of containment was damaged. Therefore, large amount of radioactive material was released to environment. Because the social and economic effects of severe accidents are enormous, Korean Government already issued 'Severe Accident Policy' in 2001 which requires nuclear power plant operators to set up 'Quantitative Safety Goal', to do 'Probabilistic Safety Analysis', to install 'Severe Accident Countermeasures' and to make 'Severe Accident Management Plan'. After the Fukushima disaster, a Special Safety Inspection was performed for all operating nuclear power plants of Korea. The inspection team from industry, academia, and research institutes assessed Korean NPPs capabilities to cope with or respond to severe accidents and emergency situation caused by natural disasters such as a large earthquake or tsunami. As a result of the special inspection, about 50 action items were identified to increase the capability to cope with natural disaster and severe accidents. Nuclear Safety Act has been amended to require NPP operators to submit Accident Management Plant as part of operating license application. The KINS Severe Accident Regulation Preparation TFT had first investigated oversea severe accident regulation trend before and after the Fukushima accident. Then, the TFT has developed regulation draft for severe accidents such as Severe accident Management Plans, the required design features for new NPPs to prevent severe accident against multiple failures and beyond-design external events, countermeasures to mitigate severe accident and to keep the integrity of containment, and assessment methodology on safety assessment plan and probabilistic safety assessment

Nowcasting of Lightning-Related Accidents in Africa

Science.gov (United States)

Ihrlich, Laura; Price, Colin

2016-04-01

Tropical Africa is the world capital of thunderstorm activity with the highest density of strikes per square kilometer per year. As a result it is also the continent with perhaps the highest casualties and injuries from direct lightning strikes. This region of the globe also has little lightning protection of rural homes and schools, while many casualties occur during outdoor activities (e.g. farming, fishing, sports, etc.) In this study we investigated two lightning-caused accidents that got wide press coverage: A lightning strike to a Cheetah Center in Namibia which caused a huge fire and great destruction (16 October 2013), and a plane crash in Mali where 116 people died (24 July 2014). Using data from the World Wide Lightning Location Network (WWLLN) we show that the lightning data alone can provide important early warning information that can be used to reduce risks and damages and loss of life from lightning strikes. We have developed a now-casting scheme that allows for early warnings across Africa with a relatively low false alarm rate. To verify the accuracy of our now-cast, we have performed some statistical analysis showing relatively high skill at providing early warnings (lead time of a few hours) based on lightning alone. Furthermore, our analysis can be used in forensic meteorology for determining if such accidents are caused by lightning strikes.

[Work-related accidents on oil drilling platforms in the Campos Basin, Rio de Janeiro, Brazil].

Science.gov (United States)

Freitas, C M; Souza, C A; Machado, J M; Porto, M F

2001-01-01

The offshore oil industry is characterized by complex systems in relation to technology and organization of work. Working conditions are hazardous, resulting in accidents and even occasional full-scale catastrophes. This article is the result of a study on work-related accidents in the offshore platforms in the Campos Basin, Rio de Janeiro State. The primary objective was to provide technical back-up for both workers' representative organizations and public authorities. As a methodology, we attempt to go beyond the immediate causes of accidents and emphasize underlying causes related to organizational and managerial aspects. The sources were used in such a way as to permit classification in relation to the type of incident, technological system, operation, and immediate and underlying causes. The results show the aggravation of safety conditions and the immediate need for public authorities and the offshore oil industry in Brazil to change the methods used to investigate accidents in order to identify the main causes in the organizational and managerial structure of companies.

Aerial spraying to capture released radioactivity from NPP in a severe accident

Energy Technology Data Exchange (ETDEWEB)

Younus, Irfan; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of); Medard, Thiphaine [Ecole des Mines de Saint-Etienne, Daejeon (Korea, Republic of)

2016-05-15

The proposed strategy in this paper is the use of aqueous spray (water/foam) mixed with suitable chemical additives to capture, dissolve and stabilize the radioactive gases and aerosol particles released from leaked reactor containment and auxiliary building. The spray system can be approached to the leaked reactor building through the use of a truck with high rising cranes, unmanned aerial vehicles (UAVs, such as helicopters), aerostats, or by installing fixed piping structure around the containment building depending on the accident situation. Laboratory-scale experimental system was setup to examine the performance of such systems. The alkaline water (aqueous NaOH.Na{sub 2}S{sub 2}O{sub 3}) and foam-based spray material (sodium lauryl sulphate) were used to examine capture efficiency of gaseous iodine and aerosol particles. The gaseous iodine and aerosol removal efficiency of foam-based spray is higher when compared with alkaline water-based spray. 2. The nozzle producing full cone spray provides the better removal efficiency than nozzle producing hollow cone spray patterns.

Fukushima nuclear accident and the social responsibility of science

International Nuclear Information System (INIS)

Yoshioka, Hitoshi

2011-01-01

Five months had passed since Fukushima Daiichi Nuclear Power Plant (NPP) accident occurred but still there was no knowing when the accident ended. Released radioactivity seemed to be greater than one million terra Bq and if there occurred an explosive rupture of containment vessel due to the failure of containment vent or occurrence of steam explosion, the amount of released radioactivity might amount to be at least equivalent to or surpass that of Chernobyl NPP accident. There existed still a risk that overheating and meltdown of nuclear fuels might reoccur with loss of cooling due to a possible giant aftershock. This article described total views on significant disaster that the accident brought about on many neighboring residents or wide range of people. After a general discussion about what was social responsibility of scientists, social responsibility of scientists for Fukushima Daiichi NPP accident was discussed. Responsibility of omission was also argued. (T. Tanaka)

LOA-1: prevent accidents. Quarterly technical progress report, FRSP program - July through September 1981

International Nuclear Information System (INIS)

1981-01-01

Information related to LMFBR reactor safety is presented concerning common cause failures; shutdown by self-activated system; shutdown heat removal system operation; sodium burning; core catcher material interactions; accident release of sodium oxide aerosol; and LMFBR risk assessment

Individual dose due to radioactivity accidental release from fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Nie, Baojie [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230027 (China); Ni, Muyi, E-mail: muyi.ni@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); Wei, Shiping [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230027 (China)

2017-04-05

Highlights: • Conservative early dose of different unit fusion radioactivity release were assessed. • Data of accident level in INES for fusion reactor were proposed. • Method of environmental restoration time after fusion accident was proposed. • The maximum possible accident level for ITER like fusion reactor is 6. • We need 34–52 years to live after the fusion hypothetical accident. - Abstract: As an important index shaping the design of fusion safety system, evaluation of public radiation consequences have risen as a hot topic on the way to develop fusion energy. In this work, the comprehensive public early dose was evaluated due to unit gram tritium (HT/HTO), activated dust, activated corrosion products (ACPs) and activated gases accidental release from ITER like fusion reactor. Meanwhile, considering that we cannot completely eliminate the occurrence likelihood of multi-failure of vacuum vessel and tokamak building, we conservatively evaluated the public radiation consequences and environment restoration after the worst hypothetical accident preliminarily. The comparison results show early dose of different unit radioactivity release under different conditions. After further performing the radiation consequences, we find it possible that the hypothetical accident for ITER like fusion reactor would result in a level 6 accident according to INES, not appear level 7 like Chernobyl or Fukushima accidents. And from the point of environment restoration, we need at least 69 years for case 1 (1 kg HTO and 1000 kg dust release) and 34–52 years for case 2 (1 kg HTO and 10kg–100 kg dust release) to wait the contaminated zone drop below the general public safety limit (1mSv per year) before it is suitable for human habitation.

The impact of major transformations of a production process on age-related accident risks

DEFF Research Database (Denmark)

Blank, V L; Laflamme, L; Diderichsen, Finn

1996-01-01

This paper describes a study of whether accident risks were equally distributed across age categories among a population of mining workers whose work activities were suspected to be age-impaired. The impairment factors in focus are the transformation of production technology during the 80s...... and consequent changes in job content. It was hypothesized that the combined effect of these factors might lead accident risks, both non-specific (aggregated) and specific (by kind), to increase with age. Accident risk ratios (ARRs), however, proved to be higher for younger workers than older ones, in both...... the non-specific and the specific cases. However, two accident patterns (specific risks) also show relatively high ARRs among workers in their 40s (and even 30s), results that might be explained by particular exposures and/or age-related performance problems. The findings suggest that technological...

The potential importance of water pathways for spent fuel transportation accident risk

International Nuclear Information System (INIS)

Ostmeyer, R.M.

1986-01-01

This paper analyzes the potential importance of water pathway contamination for spent fuel transportation accident risk using a ''worst-case'' water contamination scenario. The scenario used for the analysis involves an accident release that occurs near a reservoir. Water pathway doses are compared to doses for accident releases in urban or agricultural areas. The results of the analysis indicate that water pathways are not important for assessing the risk of transporting spent reactor fuel by truck or by rail

Noble gas control room accident filtration system for severe accident conditions (N-CRAFT)

International Nuclear Information System (INIS)

Hill, Axel; Stiepani, Cristoph; Drechsler, Michael

2015-01-01

Severe accidents might cause the release of airborne radioactive substances to the environment of the NPP either due to containment leakages or due to intentional filtered containment venting. In the latter case aerosols and iodine are retained, however noble gases are not retainable by the FCVS or by conventional air filtration systems like HEPA filters and iodine absorbers. Radioactive noble gases nevertheless dominate the activity release depending on the venting procedure and the weather conditions. To prevent unacceptable contamination of the control room atmosphere by noble gases, AREVA GmbH has developed a noble gas control room accident filtration system (CRAFT) which can supply purified fresh air to the control room without time limitation. The retention process is based on dynamic adsorption of noble gases on activated carbon. The system consists of delay lines (carbon columns) which are operated by a continuous and simultaneous adsorption and desorption process. CRAFT allows minimization of the dose rate inside the control room and ensures low radiation exposure to the staff by maintaining the control room environment suitable for prolonged occupancy throughout the duration of the accident. CRAFT consists of a proven modular design either transportable or permanently installed. (author)

Application of the SPEEDI system to the Chernobyl reactor accident

International Nuclear Information System (INIS)

Chino, Masamichi; Ishikawa, Hirohiko; Yamazawa, Hiromi; Moriuchi, Shigeru

1986-10-01

The SPEEDI system is a computational code system to predict the radiological dose due to the plume released in a nuclear accident in Japan. This paper describes the SPEEDI's application to the Chernobyl reactor accident for the estimation of the movement of plume and the release rate of radioactive nuclides into the environment. The predicted results on the movement of plume agreed well with the monitoring data in Europe. The estimated results on the release rate showed that half of the noble gas inventory, about 5 % of the iodine inventory and about 3 % of the cesium inventory are released into the environment within 24 hours. (author)

Cold Vacuum Drying facility design basis accident analysis documentation

International Nuclear Information System (INIS)

CROWE, R.D.

2000-01-01

This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report (FSAR), ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR. The calculations in this document address the design basis accidents (DBAs) selected for analysis in HNF-3553, ''Spent Nuclear Fuel Project Final Safety Analysis Report'', Annex B, ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' The objective is to determine the quantity of radioactive particulate available for release at any point during processing at the Cold Vacuum Drying Facility (CVDF) and to use that quantity to determine the amount of radioactive material released during the DBAs. The radioactive material released is used to determine dose consequences to receptors at four locations, and the dose consequences are compared with the appropriate evaluation guidelines and release limits to ascertain the need for preventive and mitigative controls

Cold Vacuum Drying facility design basis accident analysis documentation

Energy Technology Data Exchange (ETDEWEB)

CROWE, R.D.

2000-08-08

This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report (FSAR), ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR. The calculations in this document address the design basis accidents (DBAs) selected for analysis in HNF-3553, ''Spent Nuclear Fuel Project Final Safety Analysis Report'', Annex B, ''Cold Vacuum Drying Facility Final Safety Analysis Report.'' The objective is to determine the quantity of radioactive particulate available for release at any point during processing at the Cold Vacuum Drying Facility (CVDF) and to use that quantity to determine the amount of radioactive material released during the DBAs. The radioactive material released is used to determine dose consequences to receptors at four locations, and the dose consequences are compared with the appropriate evaluation guidelines and release limits to ascertain the need for preventive and mitigative controls.

DOZIM - evaluation dose code for nuclear accident

International Nuclear Information System (INIS)

Oprea, I.; Musat, D.; Ionita, I.

2008-01-01

During a nuclear accident an environmentally significant fission products release can happen. In that case it is not possible to determine precisely the air fission products concentration and, consequently, the estimated doses will be affected by certain errors. The stringent requirement to cope with a nuclear accident, even minor, imposes creation of a computation method for emergency dosimetric evaluations needed to compare the measurement data to certain reference levels, previously established. These comparisons will allow a qualified option regarding the necessary actions to diminish the accident effects. DOZIM code estimates the soil contamination and the irradiation doses produced either by radioactive plume or by soil contamination. Irradiations either on whole body or on certain organs, as well as internal contamination doses produced by isotope inhalation during radioactive plume crossing are taken into account. The calculus does not consider neither the internal contamination produced by contaminated food consumption, or that produced by radioactive deposits resuspension. The code is recommended for dose computation on the wind direction, at distances from 10 2 to 2 x 10 4 m. The DOZIM code was utilized for three different cases: - In air TRIGA-SSR fuel bundle destruction with different input data for fission products fractions released into the environment; - Chernobyl-like accident doses estimation; - Intervention areas determination for a hypothetical severe accident at Cernavoda Nuclear Power Plant. For the first case input data and results (for a 60 m emission height without iodine retention on active coal filters) are presented. To summarize, the DOZIM code conception allows the dose estimation for any nuclear accident. Fission products inventory, released fractions, emission conditions, atmospherical and geographical parameters are the input data. Dosimetric factors are included in the program. The program is in FORTRAN IV language and was run on

Fission product release mechanisms and groupings

Energy Technology Data Exchange (ETDEWEB)

Iglesia, F C; Brito, A C; Liu, Y [Ontario Hydro, Toronto, ON (Canada); and others

1996-12-31

During CANDU postulated accidents the reactor fuel is estimated to be exposed to a variety of conditions. These conditions are dynamic and, during the course of an accident, the fuel may experience a wide range of temperatures and conditions from highly oxidizing to mildly reducing environments. The exposure of the reactor fuel to these environments and temperatures may affect its stoichiometry and release performance. In this paper a review of the important fission product release mechanisms is presented, the results of three out-of-pile experimental programs are summarized, and fission product release groups, for both oxidizing and reducing conditions are proposed. (author) 92 refs., 6 tabs.

Severe accidents in Nuclear Power Plants

International Nuclear Information System (INIS)

Valle Cepero, R.; Castillo Alvarez, J.; Ramon Fuente, J.

1996-01-01

For the assessment of the safety of nuclear power plants it is of great importance the analyses of severe accidents since they allow to estimate the possible failure models of the containment, and also permit knowing the magnitude and composition of the radioactive material that would be released to the environment in case of an accident upon population and the environment. This paper presents in general terms the basic principles for conducting the analysis of severe accidents, the fundamental sources in the generation of radionuclides and aerosols, the transportation and deposition processes, and also makes reference to de main codes used in the modulation of severe accidents. The final part of the paper contents information on how severe accidents are dialed with the regulatory point view in different countries

Environmental consequences of releases from nuclear accidents

International Nuclear Information System (INIS)

Tveten, U.

1990-03-01

The report presents the results of a four-year Nordic cooperation project (AKTU-200). The results have impact upon many facets of accident consequence assessment, ranging from new computational tools to recommendations concerning food preparation methods to be utilized in a fallout situation. Some of the subprojects have approached areas where little or no research has been performed previously, like the project on winter conditions, the project on the physico/chemical form of radionuclides in the Chernobyl fallout, and the project on resuspension. The conclusion from the first of these projects is that the impact of an accident or fallout situation occuring during winter may be considerable smaller than in a similar situation during summer conditions. The most important conclusion from the second of these projects is that bioavailability of radiocesium in soil is significantly lower than that of radiocesium in plant material taken up via the roots. In the third project is was found that the resuspension factor is several orders of magnitude lower than the values traditionally cited, and that resuspension is a local phenomenon in a majority of weather conditions. The development of large-scale testing of mitigating actions to prevent uptake of radiocesium in animals in a fallout situation is also one of the projects where new ground has been sucessfully broken. 189 refs., 89 figs., 55 tabs

Radiation and health effects. A report on the TMI-2 accident and related health studies

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-08-01

damaged fuel was prevented from escaping from the reactor plant into the environment. Radioactivity which was released into the environment consisted primarily of the noble gases xenon and krypton. Small amounts of radioactive iodine and trace quantities of several other radioactive elements also escaped into the environment. Radiation doses to humans and the environment were measured by radiation detectors and calculated from environmental samples. Nearly 10,000 samples of air, water, milk, fish, fruits, meat, soil and river sediment were analyzed and demonstrated that radioactivity released to the environment was small and will have no detectable impact on human health. The accident was investigated and all available scientific data have been analyzed by a number of independent committees of experts. There was general agreement among all these investigative committees that the radiation doses to the general public were small. Among the important findings, all of which have been published, are: The highest possible whole-body dose to any one individual was less than 100 millirems (0.1 rem); The average whole-body dose to individuals within 10 miles of TMI was less than 8 millirems (0.008 rem); The average whole-bode dose to individuals within 50 miles of TMI was less than 1.5 millirems (0.0015 rem); On the basis of these radiation doses, it can be concluded that the potential health effects, if any, would be so small as to be undetectable. These radiation doses can be viewed in perspective when it is recognized that, in any given year, each person in the United States receives approximately 100 millirems (0.1 rem) of natural background radiation exposure. Medical and dental radiation for the average American contributes approximately an additional 90 millirems (0.09 rem) per year. The one-time radiation doses resulting from the radioactivity released during the TMI-2 accident, therefore, represent only a small fraction of the yearly radiation dose that all of us receive

Accident analysis in nuclear power plants

International Nuclear Information System (INIS)

Silva, D.E. da

1981-01-01

The way the philosophy of Safety in Depth can be verified through the analysis of simulated accidents is shown. This can be achieved by verifying that the integrity of the protection barriers against the release of radioactivity to the environment is preserved even during accident conditions. The simulation of LOCA is focalized as an example, including a study about the associated environmental radiological consequences. (Author) [pt

MODELS SELECTED FOR CALCULATION OF DOSES, HEALTH EFFECTS AND ECONOMIC COSTS DUE TO ACCIDENTAL RADIONUCLIDE RELEASES FROM NUCLEAR POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

Strenge, D L; Baker, D A; Droppo, J G; McPherson, R B; Napier, B A; Nieves, L A; Soldat, J K

1980-05-01

Models are described for use in site-specific environmental consequence analysis of nuclear reactor accidents of Classes 3 through 9. The models presented relate radioactivity released to resulting doses, health effects, and costs of remedial actions. Specific models are presented for the major exposure pathways of airborne releases, waterborne releases and direct irradiation from activity within the facility buildings, such as the containment. Time-dependent atmospheric dispersion parameters, crop production parameters and other variable parameters are used in the models. The environmental effects are analyzed for several accident start times during the year.

Regulation Plans on Severe Accidents developed by KINS Severe Accident Regulation Preparation TFT

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyun Tae; Chung, Ku Young; Na, Han Bee [KINS, Daejeon (Korea, Republic of)

2016-05-15

Some nuclear power plants in Fukushima Daiichi site had lost their emergency reactor cooling function for long-time so the fuels inside the reactors were molten, and the integrity of containment was damaged. Therefore, large amount of radioactive material was released to environment. Because the social and economic effects of severe accidents are enormous, Korean Government already issued 'Severe Accident Policy' in 2001 which requires nuclear power plant operators to set up 'Quantitative Safety Goal', to do 'Probabilistic Safety Analysis', to install 'Severe Accident Countermeasures' and to make 'Severe Accident Management Plan'. After the Fukushima disaster, a Special Safety Inspection was performed for all operating nuclear power plants of Korea. The inspection team from industry, academia, and research institutes assessed Korean NPPs capabilities to cope with or respond to severe accidents and emergency situation caused by natural disasters such as a large earthquake or tsunami. As a result of the special inspection, about 50 action items were identified to increase the capability to cope with natural disaster and severe accidents. Nuclear Safety Act has been amended to require NPP operators to submit Accident Management Plant as part of operating license application. The KINS Severe Accident Regulation Preparation TFT had first investigated oversea severe accident regulation trend before and after the Fukushima accident. Then, the TFT has developed regulation draft for severe accidents such as Severe accident Management Plans, the required design features for new NPPs to prevent severe accident against multiple failures and beyond-design external events, countermeasures to mitigate severe accident and to keep the integrity of containment, and assessment methodology on safety assessment plan and probabilistic safety assessment.

Radiation and health effects. A report on the TMI-2 accident and related health studies

International Nuclear Information System (INIS)

1986-08-01

damaged fuel was prevented from escaping from the reactor plant into the environment. Radioactivity which was released into the environment consisted primarily of the noble gases xenon and krypton. Small amounts of radioactive iodine and trace quantities of several other radioactive elements also escaped into the environment. Radiation doses to humans and the environment were measured by radiation detectors and calculated from environmental samples. Nearly 10,000 samples of air, water, milk, fish, fruits, meat, soil and river sediment were analyzed and demonstrated that radioactivity released to the environment was small and will have no detectable impact on human health. The accident was investigated and all available scientific data have been analyzed by a number of independent committees of experts. There was general agreement among all these investigative committees that the radiation doses to the general public were small. Among the important findings, all of which have been published, are: The highest possible whole-body dose to any one individual was less than 100 millirems (0.1 rem); The average whole-body dose to individuals within 10 miles of TMI was less than 8 millirems (0.008 rem); The average whole-bode dose to individuals within 50 miles of TMI was less than 1.5 millirems (0.0015 rem); On the basis of these radiation doses, it can be concluded that the potential health effects, if any, would be so small as to be undetectable. These radiation doses can be viewed in perspective when it is recognized that, in any given year, each person in the United States receives approximately 100 millirems (0.1 rem) of natural background radiation exposure. Medical and dental radiation for the average American contributes approximately an additional 90 millirems (0.09 rem) per year. The one-time radiation doses resulting from the radioactivity released during the TMI-2 accident, therefore, represent only a small fraction of the yearly radiation dose that all of us receive

Plutonium emission from the Fukushima accident

International Nuclear Information System (INIS)

Bossew, P.

2013-01-01

A strong earthquake and subsequent tsunami on 11 th March 2011 initiated a severe accident in units 1 to 4 of Fukushima Dai-ichi nuclear power plant, resulting in substantial releases of radionuclides. While much has since been published 00 environmental contamination and exposure to radio--iodine and radio-caesium, little is known about releases of plutonium and other non-volatile elements. Although the total activities of released 131 I, 134 Cs and 137 Cs are of the same order of magnitude as of the Chernobyl accident in 1986, the contribution of little volatile elements, including Pu, is much smaller in Fukushima fallout. The reason is the different physical nature of the accident sequence which led to a release of some 10 - 5% of the core inventories only (to be compared with 3.5% from Chernobyl). In this contribution the available data on Pu in Fukushima fallout will be reviewed. Data sources are mainly reports and press releases by Japanese authorities and a few scientific articles. The mean ratio 239+240 Pu: 137 Cs in the near field around the NPP (mainly part of Fukushima prefecture and districts of adjacent prefectures) can be assumed about 3 x 10 - 7 , to be compared to nearly 0.01 in the vicinity of Chernobyl, down to about 3 x 10 -6 in Central Europe. Isotopic ratios 238 Pu: 239+240 Pu are about 2.2 (0.46 and 0.035 in Chemobyl and global fallout, respectively). Activity concentrations of Fukushima- 239+240 Pu in surface soil were found up to above 0.1 Bq/kg d.m. in the immediate vicinity of the Fukushima NPP and about one order of magnitude less in Fukushima city, about 60 km away. The 239+240 Pu activity released into the atmosphere is roughly estimated some 10 9 Bq (Chemobyl : almost 10 14 Bq). (author)

Conservatism in effective dose calculations for accident events involving fuel reprocessing waste tanks.

Science.gov (United States)

Bevelacqua, J J

2011-07-01

Conservatism in the calculation of the effective dose following an airborne release from an accident involving a fuel reprocessing waste tank is examined. Within the regulatory constraints at the Hanford Site, deterministic effective dose calculations are conservative by at least an order of magnitude. Deterministic calculations should be used with caution in reaching decisions associated with required safety systems and mitigation philosophy related to the accidental release of airborne radioactive material to the environment.

Safety against releases in severe accidents. Annual report 1996. Project plan 1997

International Nuclear Information System (INIS)

1997-01-01

The work scope of the RAK-2 project is divided into three sub-projects: RAK-2.1 Severe Accident Phenomenology; RAK-2.2 Computerised Accident Management; RAK-2.3 Reactors In Nordic Surroundings. The work in subproject 1 progresses roughly according to budget and time schedule. Some adjustments in the technical work scope were made during 1996. Main tasks of RAK-2.1 in 1996: Complete recriticality studies for Nordic BWRs; Investigate phenomena related to late phase melt progression; Issue and NKS Final Technical Report on KTH experiments. Main tasks of RAK-2.2 in 1996: CAMS would be further developed with signal validation, tracking simulation, state identification and PSA and risk monitoring applications; Carry out a feasibility study for development of a PWR version of CAMS in collaboration with EdF, France; Use CAMS in the Halden Man-Machine laboratory to perform human factor studies. Main tasks of RAK-2.3 in 1996: Collect and report data from the British reactor types AGR, MAGNOX and PWR; Make a report on accidents in nuclear ships; Put the collected data together in a common data base covering neighbour reactors treated in SIK-3 and RAK-2.3; Update the data in the former SIK-3 report if needed. The work in project 2 progresses according to plans. The data collection of British reactors with in sub-project 3 has been delayed significantly due to difficulty of obtaining information from some of the British utilities, but the problems are expected to be solved by the end of 1997. (EG)

Identification and assessment of containment and release management strategies

International Nuclear Information System (INIS)

Lehner, J.R.; Lin, C.C.; Neogy, P.

1990-01-01

Brookhaven National Laboratory, under the auspices of the US Nuclear Regulatory Commission, is investigating accident management strategies which could help preserve containment integrity or minimize releases during a severe accident. The objective is to make use of existing plant systems and equipment in innovative ways to reduce the likelihood of containment failure or to mitigate the release of fission products to the environment if failure cannot be prevented. Many of the strategies would be implemented during the later stages of a severe accident. The identification and assessment process for containment and release strategies is described, and some insights derived from its application to a BWR Mark 1 plant are presented here. 13 refs., 2 figs

Investigation Effect of Biorhythm on Work-Related Accidents in The Metal Industry (A Short Report

Directory of Open Access Journals (Sweden)

Ehsanollah Habibi

2016-07-01

Full Text Available Biorhythm is one of the newest subjects in the field of cognition of mental ergonomics which can be very effective in reduction of work-related accidents or mistakes with no apparent reason. With evaluating Biorhythm individuals can intervention action to reduce job accidents carried out. Thus, the aim of this study was to determine the relationship Biorhythm and work-related accidents in the metal industry. This research is a cross-sectional and analytical-descriptive in the metal industrial Isfahan city of 120 work-related accidents during 2015. The required information was collected from available documents in HSE unit of the company biorhythm charts were drawn based on a date of accidents and participants birthdays, using natural Biorhythm Software V3.02 Conduct. Finally، the data were analyzed using spss version 20 and descriptive statistics.This study showed that the frequency of accidents in critical days and negative section of physical cycle was more than expected. Also the frequency of accidents in critical days and negative section of emotional and intellectual cycles was less than expected. Most type of injury, including cuts to 35.8 percent and the lowest type of injury was torsion with 5 percent. Most limb injury, hands and fingers with 51.7 percent and the lowest limb injury were back at 2.5 percent. Accidents outbreak in physical cycles was 38.3 percent. These 120 accidents in additionally were causing 120 loss of working days in effect accident. Most percent of loss of working days were for 20 to 30 days with of 39.2 percent. Most percent of loss of working days were for 20 to 30 days with of 39.2 percent. Due to the physical nature of the work activities in the metal industry can be stated that the study showed that in physical work activities, frequency of accidents in critical days and negative section of physical cycle in which the person is not physically ready to do the job was more than expected. Therefore, by training

Review of the CRAC and SILENE Criticality Accident Studies

International Nuclear Information System (INIS)

Barbry, F.; Fouillaud, P.; Grivot, P.; Reverdy, L.

2009-01-01

In 1967, the Commissariat et l'Energie Atomique (French Atomic Energy Agency) performed its first research on criticality accidents for the purpose of limiting their impact on people, the environment, and nuclear facilities themselves. A criticality accident is accompanied by intense neutron and gamma emissions and release of radioactive fission products-gases and aerosols-gene rating risk of irradiation and contamination. This work has supplemented earlier work in criticality safety, which concentrated on critical mass measurements and computations. Understanding of the consequences of criticality accidents was limited. Emergency planning was hampered by lack of data. Information became available from pulsed reactor experiments, but the experiments were restricted to the established reactor configurations. The objectives of research performed at the Valduc criticality laboratory, mainly on aqueous fissile media, using the CRAC and SILENE facilities, by multidisciplinary teams of physicists, dosimetry specialists, and radio-biologists, were to model criticality accident physics, estimate irradiation risks and radioactive releases, detect excursions, and organize emergency response. The results of the Valduc experiments have contributed toward improved understanding of criticality accident phenomenology and better evaluation of the risks associated with such accidents. (authors)

Review of the CRAC and SILENE Criticality Accident Studies

Energy Technology Data Exchange (ETDEWEB)

Barbry, F.; Fouillaud, P.; Grivot, P.; Reverdy, L. [CEA Valduc, Serv Rech Neutron and Critcite, 21 - Is-sur-Tille (France)

2009-02-15

In 1967, the Commissariat et l'Energie Atomique (French Atomic Energy Agency) performed its first research on criticality accidents for the purpose of limiting their impact on people, the environment, and nuclear facilities themselves. A criticality accident is accompanied by intense neutron and gamma emissions and release of radioactive fission products-gases and aerosols-gene rating risk of irradiation and contamination. This work has supplemented earlier work in criticality safety, which concentrated on critical mass measurements and computations. Understanding of the consequences of criticality accidents was limited. Emergency planning was hampered by lack of data. Information became available from pulsed reactor experiments, but the experiments were restricted to the established reactor configurations. The objectives of research performed at the Valduc criticality laboratory, mainly on aqueous fissile media, using the CRAC and SILENE facilities, by multidisciplinary teams of physicists, dosimetry specialists, and radio-biologists, were to model criticality accident physics, estimate irradiation risks and radioactive releases, detect excursions, and organize emergency response. The results of the Valduc experiments have contributed toward improved understanding of criticality accident phenomenology and better evaluation of the risks associated with such accidents. (authors)

The retardation effect of structural graphite on the release of fission products in case of hypothetical accidents of HTRs

International Nuclear Information System (INIS)

Iniotakis, N.; Decken, C.B. von der

1982-01-01

In case of a hypothetical core heat up accident of an HTR the structural graphite of the reactor causes under certain circumstances a very important retardation of the release of fission products into the containment building of the plant. A model is presented which describes the transport phenomena in the graphite structure extensively taking into account specially the macro-structure of the graphite. It is shown by parameter variations under which conditions one can expect a large retardation effect and quantitative values of this retardation, which can be very important, are given. (author)

Human exposure to radiation following the release of radioactivity from a reactor accident: a quantitative assessment of the biological consequences

International Nuclear Information System (INIS)

Smith, H.; Stather, J.W.

1976-11-01

The objective of this review is to provide a biological basis upon which to assess the consequences of the exposure of a population to radioactivity released after a reactor accident. Depending upon the radiation dose, both early and late somatic damage could occur in the exposed population and hereditary effects may occur in their descendants. The development of dose-effect relationships has been based upon the limited amount of information available on humans, supplemented by data obtained from experiments on animals. (author)

A thermodynamic/mass-transport model for the release of ruthenium from irradiated fuel

International Nuclear Information System (INIS)

Garisto, F.; Iglesias, F.C.; Hunt, C.E.L.

1990-01-01

Some postulated nuclear reactor accidents lead to fuel failures and hence release of fission products into the primary heat transport system (PHTS). To determine the consequences of such accidents, it is important to understand the behavior of fission products both in the PHTS and in the reactor containment building. Ruthenium metal has a high boiling point and is nonvolatile under reducing conditions. However, under oxidizing conditions ruthenium can form volatile oxides at relatively low temperatures and, hence, could escape from failed fuel and enter the containment building. The ruthenium radioisotope Ru-106 presents a potentially significant health risk if it is released outside the reactor containment building. Consequently, it is important to understand the behavior of ruthenium during a nuclear reactor accident. The authors review the thermodynamic behavior of ruthenium at high temperatures. The qualitative behavior of ruthenium, predicted using thermodynamic calculations, is then compared with experimental results from the Chalk River Nuclear Laboratories (CRNL). Finally, a simple thermodynamic/mass-transport model is proposed to explain the release behavior of ruthenium in a steam atmosphere

EPRI nuclear fuel-cycle accident risk assessment

International Nuclear Information System (INIS)

Anon.

1981-01-01

The present results of the nuclear fuel-cycle accident risk assessment conducted by the Electric Power Research Institute show that the total risk contribution of the nuclear fuel cycle is only approx. 1% of the accident risk of the power plant; hence, with little error, the accident risk of nuclear electric power is essentially that of the power plant itself. The power-plant risk, assuming a very large usage of nuclear power by the year 2005 is only approx. 0.5% of the radiological risk of natural background. The smallness of the fuel-cycle risk relative to the power-plant risk may be attributed to the lack of internal energy to drive an accident and the small amount of dispersible material. This work aims at a realistic assessment of the process hazards, the effectiveness of confinement and mitigation systems and procedures, and the associated likelihood of errors and the estimated size of errors. The primary probabilistic estimation tool is fault-tree analysis, with the release source terms calculated using physicochemical processes. Doses and health effects are calculated with CRAC (Consequences of Reactor Accident Code). No evacuation or mitigation is considered; source terms may be conservative through the assumption of high fuel burnup (40,000 MWd/t) and short cooling period (90 to 150 d); high-efficiency particulate air filter efficiencies are derived from experiments

[Risk factors associated with work-related accidents in the construction industry in the Valley of Mexico].

Science.gov (United States)

Sarmiento-Salinas, Rodrigo; López-Rojas, Pablo; Marín-Cotoñieto, Irma Araceli; Godínez-Rocha, Arturo; Haro-García, Luis; Salinas-Tovar, Santiago

2004-01-01

Our aim was to describe construction-industry, work-related accident prevalence in, associated factors in, and potential impact on affiliated workers of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social, IMSS) in the Valley of Mexico. Prevalent cases in a retrospective case-control design. These include 385 construction-industry workers who were found to have construction work-related accidents in 2001. Controls comprised 385 active construction-industry workers without work-related accident background paired by gender, workplace, and worksite. Work-related accident prevalence in construction workers was 5.5%; most important risk factors and etiology fraction (Ef) included the following: age 16-20 years odds ratio, OR = 1.58, 95% confidence interval (95% CI) 1.40-10.7, p = 0.001, Ef 0.36; eventual insurance, OR = 3.7, 95% CI, 2.16-26.45, p = 0.001), Ef, 0.72, and no training for job, OR = 5.3, 95% CI, 4.9-69.2, p = 0.01), Ef: 0.81. Variables not showing significance were included salary, work shift, and workday. Work-related accident prevalence maintains its preponderance in the Valley of Mexico construction industry; identified risk factors are potentially modifiable, among which job training acquires unquestionable relevance.

Application of RASCAL code for multiunit accident in domestic nuclear sites

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Hyun; Jeong, Seung Young [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2014-10-15

All of domestic nuclear power plant sites are multiunit site (at least 5 - 6 reactors are operating), so this capability has to be quickly secured for nuclear licensee and institutes responsible for nuclear emergency response. In this study, source term and offsite dose from multiunit event were assessed using a computer code, RASCAL. An emergency exercise scenario was chosen to verify applicability of the codes to domestic nuclear site accident. Employing tools and new features of the code, such as merging more than two individual source terms and source term estimate for long term progression accident, main parameters and information in the scenario, release estimates and dose projections were performed. Radiological releases and offsite doses from multiunit accident were calculated using RASCAL.. A scenario, in which three reactors were damaged coincidently by a great natural disaster, was considered. Surrogate plants were chosen for the code calculation. Source terms of each damaged unit were calculated individually first, and then total source term and integrated offsite dose assessment data was acquired using a source term merge function in the code. Also comparison between LTSBO and LOCA source term estimate options was performed. Differences in offsite doses were caused by release characteristics. From LTSBO option, iodines were released much higher than LOCA. Also LTSBO source term release was delayed and the duration was longer than LOCA. This option would be useful to accidents which progress with much longer time frame than LOCA. RASCAL can be useful tool for radiological consequence assessment in domestic nuclear site accidents.

Chemistry of fission product iodine under nuclear reactor accident conditions

International Nuclear Information System (INIS)

Malinauskas, A.P.; Bell, J.T.

1986-01-01

The radioisotopes of iodine are generally acknowledged to be the species whose release into the biosphere as a result of a nuclear reactor accident is of the greatest concern. In the course of its release, the fission product is subjected to differing chemical environments; these can alter the physicochemical form of the fission product and thus modify the manner and extent to which release occurs. Both the chemical environments which are characteristic of reactor accidents and their effect in determining physical and chemical form of fission product iodine have been studied extensively, and are reviewed in this report. 76 refs

[Analisys of work-related accidents and incidents in an oil refinery in Rio de Janeiro].

Science.gov (United States)

de Souza, Carlos Augusto Vaz; de Freitas, Carlos Machado

2003-01-01

Accidents in the chemical industry can have serious consequences for workers, communities, and the environment and are thus highly relevant to public health. This article is the result of an occupational surveillance project involving several public institutions. We analyze 800 work-related accidents that resulted in injuries, environmental damage, or loss of production in 1997 in an oil refinery located in Rio de Janeiro, Brazil. The methodology was based on managerial and organizational approaches to accident investigation, with the European Union reporting system as the reference. The results highlight various limitations in the process of reporting and investigating accidents, as well as a certain hierarchy of accidents, with more attention given to accidents involving loss of production and less to those resulting in injuries, particularly among outsourced workers.

Compilation of accident statistics in PSE

International Nuclear Information System (INIS)

Jobst, C.

1983-04-01

The objective of the investigations on transportation carried out within the framework of the 'Project - Studies on Safety in Waste Management (PSE II)' is the determination of the risk of accidents in the transportation of radioactive materials by rail. The fault tree analysis is used for the determination of risks in the transportation system. This method offers a possibility for the determination of frequency and consequences of accidents which could lead to an unintended release of radionuclides. The study presented compiles all data obtained from the accident statistics of the Federal German Railways. (orig./RB) [de

Safety analysis results for cryostat ingress accidents in ITER

International Nuclear Information System (INIS)

Merrill, B.J.; Cadwallader, L.C.; Petti, D.A.

1996-01-01

Accidents involving the ingress of air or water into the cryostat of the International Thermonuclear Experimental Reactor (ITER) tokamak design have been analyzed with a modified version of the MELCOR code for the ITER Non-site Specific Safety Report (NSSR-1). The air ingress accident is the result of a postulated breach of the cryostat boundary into an adjoining room. MELCOR results for this accident demonstrate that the condensed air mass and increased heat loads are not a magnet safety concern, but that the partial vacuum in the adjoining room must be accommodated in the building design. The water ingress accident is the result of a postulated magnet arc that results in melting of a Primary Heat Transport System (PHTS) coolant pipe, discharging PHTS water and PHTS water activated corrosion products and HTO into the cryostat. MELCOR results for this accident demonstrate that the condensed water mass and increased heat loads are not a magnet safety concern, that the cryostat pressure remains below design limits, and that the corrosion product and HTO releases are well within the ITER release limits

Global atmospheric dispersion modelling after the Fukushima accident

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

Impact on the marine environment of radioactive releases resulting from the Fukushima-Daiichi nuclear accident. April 4, 2011

International Nuclear Information System (INIS)

2011-01-01

After having outlined that measurements taken over several days in the sea water in the vicinity of the power station have revealed severe contamination of the marine environment by various radionuclides released as a result of the accident at the Fukushima-Daiichi nuclear power station, this report describes the origins of the contamination of the marine environment (release of liquid effluents directly into the sea in the vicinity of the damaged reactors, atmospheric fallout onto the surface of the sea, conveyance of radioactive pollution by rainout of contaminated ground). Then, while proposing several maps, the authors analyse and comment the dispersion in the sea of radioactive pollutants by addressing the following issues: topography of the sea bed and sea currents off the Japanese coast, immediate or short term dispersion (a few days), mid-term dispersion (weeks and months), long term and large scale future of the radioactive pollutants. Finally, the report briefly discusses the impact of radioactive pollution on living species

On high-temperature reactor accident topology

International Nuclear Information System (INIS)

Fassbender, J.; Kroeger, W.; Wolters, J.

1981-01-01

American and German risk studies for an HTGR and independent investigations of hypothetical accident sequences led to a fundamental understanding of the topology of HTGR accident sequences. The dominating importance of core heat-up accidents was confirmed and the initiating events were identified. Complications of core heat-up accidents by air or water ingress are of minor importance for the risk, whereas the long-term development of accidents during days and weeks plays an important role for the environmental impact. The risk caused by an HTGR at a German site cannot yet be determined exactly, because no modern German HTGR design has passed a licensing procedure. Cautious estimates show that risk will appear to be substantially smaller than the LWR risk. The main reasons are the considerably reduced release of fission procucts and the slow development of core heat-up accidents leaving much time for measures which reduce the risk. (orig.) [de

Source term estimation during incident response to severe nuclear power plant accidents

International Nuclear Information System (INIS)

McKenna, T.J.; Glitter, J.G.

1988-10-01

This document presents a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. 39 refs., 48 figs., 19 tabs

The consequences from liquid pathways after a reactor meltdown accident

International Nuclear Information System (INIS)

Niemczyk, S.J.; Adams, K.G.; Murfin, W.B.; Ritchie, L.T.; Eppel, E.W.; Johnson, J.D.

1981-06-01

The potential radiological impact of a core-melt accident on the human population has been investigated. In particular, the radiation dose received from radioactivity which could reach the population via liquid pathways has been considered. Radioactivity could be released directly to the hydrosphere after a core-melt accident as a result of melt-through of the containment basemat followed by any of three processes: (1) leaching of the melt debris; 2 escape of sumpwater through the hole formed by the melt (or from passage out of the containment by an alternate route); and 3) depressurization of the containment atmosphere through the melt hole. The three types of releases would differ primarily in their rates, their magnitudes and their radioactive compositions. Both the containment atmosphere and the sumpwater releases would occur relatively rapidly. However, most of the radionuclides present in these two releases in substantial quantities would be expected to be rather short-lived. Therefore, such releases could have a significant impact at a specific site only if the travel times of the important radionuclides to the human population were small. In contrast, leaching of radionuclides from the melt debris would be expected to occur relatively slowly. Most of the long-lived isotopes would be expected to be found primarily in the melt debris. Consequently, even though this release occurred relatively slowly, the impact could still be significant. In contrast to the situation for releases to the atmosphere, accidents corresponding to the most probable RSS (Reactor Safety Study) meltdown categories would result in the largest releases to the hydrosphere. Furthermore, substantial amounts of radioactivity would generally be expected to be released to the hydrosphere during any meltdown accident involving complete melt-through of the containment basemat. On the basis of subsurface hydrologies alone, sites range from those that essentially preclude any impacts to the human

Guidelines for calculating radiation doses to the public from a release of airborne radioactive material under hypothetical accident conditions in nuclear reactors

International Nuclear Information System (INIS)

1991-04-01

This standard provides guidelines and a methodology for calculating effective doses and thyroid doses to people (either individually or collectively) in the path of airborne radioactive material released from a nuclear facility following a hypothetical accident. The radionuclides considered are those associated with substances having the greatest potential for becoming airborne in reactor accidents: tritium (HTO), noble gases and their daughters, radioiodines, and certain radioactive particulates (Cs, Ru, Sr, Te). The standard focuses on the calculation of radiation doses for external exposures from radioactive material in the cloud; internal exposures for inhalation of radioactive material in the cloud and skin penetration of tritium; and external exposures from radionuclides deposited on the ground. It uses as modified Gaussian plume model to evaluate the time-integrated concentration downwind. (52 refs., 12 tabs., 21 figs.)

Toxic release consequence analysis tool (TORCAT) for inherently safer design plant

International Nuclear Information System (INIS)

Shariff, Azmi Mohd; Zaini, Dzulkarnain

2010-01-01

Many major accidents due to toxic release in the past have caused many fatalities such as the tragedy of MIC release in Bhopal, India (1984). One of the approaches is to use inherently safer design technique that utilizes inherent safety principle to eliminate or minimize accidents rather than to control the hazard. This technique is best implemented in preliminary design stage where the consequence of toxic release can be evaluated and necessary design improvements can be implemented to eliminate or minimize the accidents to as low as reasonably practicable (ALARP) without resorting to costly protective system. However, currently there is no commercial tool available that has such capability. This paper reports on the preliminary findings on the development of a prototype tool for consequence analysis and design improvement via inherent safety principle by utilizing an integrated process design simulator with toxic release consequence analysis model. The consequence analysis based on the worst-case scenarios during process flowsheeting stage were conducted as case studies. The preliminary finding shows that toxic release consequences analysis tool (TORCAT) has capability to eliminate or minimize the potential toxic release accidents by adopting the inherent safety principle early in preliminary design stage.

The post-accident protective measures in the region of the Chernobyl catastrophe

International Nuclear Information System (INIS)

Pasechnikov, A.

1993-01-01

The strategy of protective measures and the system of intervention levels are considered. It makes it possible to limit the region where post-accident measures must be taken. The concept of 'safe living' for life and surface contamination concept are discussed. The measurement results of a surface contamination are pointed out in the maps for series settlements of the 30 km zone. The features of severe accidents to nuclear power plants are that damage is caused not only by destruction and downtime of power installations, but also by radioactive contamination of the environment. Therefore, the term 'severe accident' is accepted to mean an accident with an off-site impact, which requires to perform large-scale and expensive work on elimination of the consequences of the accident. The whole off-site damage due to the Chernobyl accident is caused exclusively by contamination, as no destruction was observed beyond the site. As a result of the Chernobyl accident the greatest short-term releases of radioactive materials to the atmosphere occurred from a single source. Four elements from all the materials released from the core have determined the short-term and long-term radiological situation in the affected areas. These are iodine, cesium, strontium and plutonium. Moreover, in the releases there were highly - radioactive fragments of fuel (hot particles). 7 figs

[Study of work accidents related to human body fluids exposure among health workers at a university hospital].

Science.gov (United States)

Balsamo, Ana Cristina; Felli, Vanda Elisa Andres

2006-01-01

This descriptive and exploratory study from a quantitative approach aimed to characterize workers who were victims of work accidents related to human body fluids exposure and to evaluate the accident victim care protocol. The population consisted of 48 workers who were victims of work accidents involving exposure to human body fluids, from July 2000 to June 2001. Data were collected through a form and interviews. Results showed that nursing workers presented higher accident risk levels and that 87.50% involved piercing and cutting material, such as needles and butterflies (70%). As to the accident-related situation/activity, the workers indicated that 25% were due to an "inadequate act during the procedure"; 19.64% mentioned that "it happened" and 29.17% answered that they did not have any suggestion. This study provided important tools to review and elaborate strategies to prevent accidents involving exposure to human body fluids.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-01

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

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

International Nuclear Information System (INIS)

Routamo, T.

1996-01-01

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

Analysis of an LPG accidental release

Energy Technology Data Exchange (ETDEWEB)

Demichela, M.; Piccinini, N.; Poggio, A.

2004-03-01

An industrial LPG storage accident due to the release of propane from a tanker is described in this paper and the sequence of events that led to the collapse of a storage tank is examined using simulation software. A model taking both released flows into account as a radiant thermal contribution in the presence of flames is presented. The progression of the accident is assessed through digitalization and processing of the film of the fireball produced by about 500 L of LPG, whose diameter was calculated as approximately 50 m. (author)

Sleep Apnea Related Risk of Motor Vehicle Accidents is Reduced by Continuous Positive Airway Pressure: Swedish Traffic Accident Registry Data

Science.gov (United States)

Karimi, Mahssa; Hedner, Jan; Häbel, Henrike; Nerman, Olle; Grote, Ludger

2015-01-01

Study Objectives: Obstructive sleep apnea (OSA) is associated with an increased risk of motor vehicle accidents (MVAs). The rate of MVAs in patients suspected of having OSA was determined and the effect of continuous positive airway pressure (CPAP) was investigated. Design: MVA rate in patients referred for OSA was compared to the rate in the general population using data from the Swedish Traffic Accident Registry (STRADA), stratified for age and calendar year. The risk factors for MVAs, using demographic and polygraphy data, and MVA rate before and after CPAP were evaluated in the patient group. Setting: Clinical sleep laboratory and population based control (n = 635,786). Patients: There were 1,478 patients, male sex 70.4%, mean age 53.6 (12.8) y. Interventions: CPAP. Measurements and Results: The number of accidents (n = 74) among patients was compared with the expected number (n = 30) from a control population (STRADA). An increased MVA risk ratio of 2.45 was found among patients compared with controls (P accident risk was most prominent in the elderly patients (65–80 y, seven versus two MVAs). In patients, driving distance (km/y), EDS (Epworth Sleepiness score ≥ 16), short habitual sleep time (≤ 5 h/night), and use of hypnotics were associated with increased MVA risk (odds ratios 1.2, 2.1, 2.7 and 2.1, all P ≤ 0.03). CPAP use ≥ 4 h/night was associated with a reduction of MVA incidence (7.6 to 2.5 accidents/1,000 drivers/y). Conclusions: The motor vehicle accident risk in this large cohort of unselected patients with obstructive sleep apnea suggests a need for accurate tools to identify individuals at risk. Sleep apnea severity (e.g., apnea-hypopnea index) failed to identify patients at risk. Citation: Karimi M, Hedner J, Häbel H, Nerman O, Grote L. Sleep apnea related risk of motor vehicle accidents is reduced by continuous positive airway pressure: Swedish traffic accident registry data. SLEEP 2015;38(3):341–349. PMID:25325460

A proposal for accident management optimization based on the study of accident sequence analysis for a BWR

International Nuclear Information System (INIS)

Sobajima, M.

1998-01-01

The paper describes a proposal for accident management optimization based on the study of accident sequence and source term analyses for a BWR. In Japan, accident management measures are to be implemented in all LWRs by the year 2000 in accordance with the recommendation of the regulatory organization and based on the PSAs carried out by the utilities. Source terms were evaluated by the Japan Atomic Energy Research Institute (JAERI) with the THALES code for all BWR sequences in which loss of decay heat removal resulted in the largest release. Identification of the priority and importance of accident management measures was carried out for the sequences with larger risk contributions. Considerations for optimizing emergency operation guides are believed to be essential for risk reduction. (author)

Source term estimation during incident response to severe nuclear power plant accidents. Draft

Energy Technology Data Exchange (ETDEWEB)

McKenna, T J; Giitter, J

1987-07-01

The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. The goal is to present a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. (author)

Source term estimation during incident response to severe nuclear power plant accidents. Draft

International Nuclear Information System (INIS)

McKenna, T.J.; Giitter, J.

1987-01-01

The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. The goal is to present a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. (author)

Accidents related to the use of products and services in the city of São Luis, Brazil.

Science.gov (United States)

De Souza Dias, Líssia Maria; Diniz, Raimundo Lopes; de Macedo Guimarães, Lia Buarque

2012-01-01

This article presents a study on the accidents related to the use of products and services, as recorded at two emergency hospitals at the city São Luís, Brazil. The goal of the study was to evaluate the main types and causes of unintentional accidents as well as the more frequent injuries for further improvement of products and services. The study evaluated the victims profile (gender and age), the circumstances (activity, local and time) that lead to the accidents and the type of resulted injury. Non-parametric statistics showed that 83.64% of the accidents were related to products (57.6% of them being consumer products) and 8.6% are related to maintenance services. 57.6% of the victims were children under 15 years old, and 58.4% were male. 50.2% of accidents occurred at home, more often (44.7%) in the afternoon. The most common injury was musculoesqueletal (48.6%), 49.0% being cranioencephalic trauma and 15.2% fractures.

Maxillofacial trauma due to work-related accidents.

Science.gov (United States)

Hächl, O; Tuli, T; Schwabegger, A; Gassner, R

2002-02-01

Even though numerous reports on maxillofacial trauma exist, only a few give detailed information about work-related maxillofacial injuries. The purpose of this study was to reveal the significance of maxillofacial injuries related to accidents occurring at work by evaluating a large number of patients with maxillofacial injuries over a 9-year period. Out of the 8704 trauma patients treated between 1991 and 1999 in the Department of Oral and Maxillofacial Surgery at the University of Innsbruck, Austria, 463 (5.4%) were injured at work. All charts were reviewed and analyzed according to age, gender, cause of accident, occupation, type of injury, location and frequency of fractures. The highest incidence of maxillofacial injury was found among construction workers (a total of 124 patients, 26.8%), followed by craftsmen (102 patients, 22.0%) and office employees (69 patients, 14.9%). The sex distribution showed an overall male-to-female ratio of 11.8:1 and those in the age group most affected were between 20 and 29 years of age. The most frequent cause of injury was a blow in 48.4%, followed by falls and falls over obstacles, accounting for 27.9% and 7.1%, respectively. Of all trauma, 45.4% (210 persons) sustained 423 maxillofacial fractures, 31.7% (147 patients) suffered 232 dento-alveolar injuries, and 21.2% (98 people) showed 430 soft-tissue injuries. One-fifth (20.7%) of all patients displayed concomitant injuries with cerebral and cranial trauma being the most common. The probability of sustaining maxillofacial trauma at work is correlated to the nature of the occupation. Individuals (mostly men) using tools or machines at work are exposed to a much higher risk of work-related maxillofacial trauma.

Accident dynamics of LR-0 reactor

International Nuclear Information System (INIS)

Vorisek, M.; Tinka, I.

1981-01-01

The results are given of calculating the accident dynamics of the LR-0 light water experimental zero power reactor. Calculations of the time dependence of power, the total released energy, the temperature of fuel and its cladding were made using program FATRAP for different values of the total inserted reactivity. Using the results, an analysis is made of hypothetic accident states of the LR-0 reactor. The results are shown graphically. (J.B.)

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

Science.gov (United States)

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

2017-03-01

The media play an important role in risk communication, providing information about accidents, both nearby and far away. Each media source has its own presentation style, which could influence how the audience perceives the presented risk. This study investigates the explanatory power of 12 information sources (traditional media, new media, social media, and interpersonal communication) for the perceived risk posed by radiation released from the damaged Fukushima nuclear power plant on respondents' own health and that of the population in general. The analysis controlled for attitude toward nuclear energy, gender, education, satisfaction with the media coverage, and duration of attention paid to the coverage. The study uses a large empirical data set from a public opinion survey, which is representative for the Belgian population with respect to six sociodemographic variables. Results show that three information sources are significant regressors of perceived health-related risk of the nuclear accident: television, interpersonal communication, and the category of miscellaneous online sources. More favorable attitudes toward nuclear power, longer attention to the coverage, and higher satisfaction with the provided information lead to lower risk perception. Taken together, the results suggest that the media can indeed have a modest influence on how the audience perceives a risk. © 2016 Society for Risk Analysis.

Severe accident progression perspectives for Mark I containments based on the IPE results

International Nuclear Information System (INIS)

Lin, C.C.; Lehner, J.R.; Pratt, W.T.; Drouin, M.

1995-01-01

Based on level 2 analyses in IPE (Individual Plant Examination) submittals accident progression, perspectives were obtained for all containment types. These perspectives consisted of insights on containment failure modes, releases therein, and factors responsible for the results. To illustrate the types of perspectives acquired on severe accident progresssion, insights obtained for (BWR) Mark I containments are discussed here. Mark I containments have high strength but small volumes and rely on pressure suppression pools to condense steam released from the reactor coolant system during an accident. Accidents causing structural failure of the drywell shortly after the core debris melts through the reactor vessel were found to be dominant contributors to risk. Importance of individual containment failure mechanisms depends on plant features and in some cases on modeling assumptions; however the following mechanisms were found important: drywell shell melt-through caused by direct contact with core debris and drywell failure caused by rapid pressure/temperature pulses at time of vessel melt-through. Drywell failure caused by gradual pressure/temperature buildup due to gases and steam released during core/concrete interactions is important in some IPEs. In other IPEs vent was an important contributor. However, accidents that bypass containment (eg interfacing systems LOCA)or involve containment isolation failure were not important contributors to the CDF in any of the IPEs for Mark I plants. These accidents are also not important to risk (even though they can involve large fission product release) because their frequencies of occurrence are so much lower than frequencies of early structural failure caused by other accidents that dominate the CDF

Joint research project WASA-BOSS: Further development and application of severe accident codes. Assessment and optimization of accident management measures. Project B: Accident analyses for pressurized water reactors with the application of the ATHLET-CD code; Verbundprojekt WASA-BOSS: Weiterentwicklung und Anwendung von Severe Accident Codes. Bewertung und Optimierung von Stoerfallmassnahmen. Teilprojekt B: Druckwasserreaktor-Stoerfallanalysen unter Verwendung des Severe-Accident-Codes ATHLET-CD

Energy Technology Data Exchange (ETDEWEB)

Jobst, Matthias; Kliem, Soeren; Kozmenkov, Yaroslav; Wilhelm, Polina

2017-02-15

Within the framework of the project an ATHLET-CD input deck for a generic German PWR of type KONVOI has been created. This input deck was applied to the simulation of severe accidents from the accident categories station blackout (SBO) and small-break loss-of-coolant accidents (SBLOCA). The complete accident transient from initial event at full power until the damage of reactor pressure vessel (RPV) is covered and all relevant severe accident phenomena are modelled: start of core heat up, fission product release, melting of fuel and absorber material, oxidation and release of hydrogen, relocation of molten material inside the core, relocation to the lower plenum, damage and failure of the RPV. The model has been applied to the analysis of preventive and mitigative accident management measures for SBO and SBLOCA transients. Therefore, the measures primary side depressurization (PSD), injection to the primary circuit by mobile pumps and for SBLOCA the delayed injection by the cold leg hydro-accumulators have been investigated and the assumptions and start criteria of these measures have been varied. The time evolutions of the transients and time margins for the initiation of additional measures have been assessed. An uncertainty and sensitivity study has been performed for the early phase of one SBO scenario with PSD (until the start of core melt). In addition to that, a code -to-code comparison between ATHLET-CD and the severe accident code MELCOR has been carried out.

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

International Nuclear Information System (INIS)

Mehboob, Khurram; Xinrong, Cao; Ahmed, Raheel; Ali, Majid

2013-01-01

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

Effective Factors in Severity of Traffic Accident-Related Traumas; an Epidemiologic Study Based on the Haddon Matrix.

Science.gov (United States)

Masoumi, Kambiz; Forouzan, Arash; Barzegari, Hassan; Asgari Darian, Ali; Rahim, Fakher; Zohrevandi, Behzad; Nabi, Somayeh

2016-01-01

Traffic accidents are the 8(th) cause of mortality in different countries and are expected to rise to the 3(rd) rank by 2020. Based on the Haddon matrix numerous factors such as environment, host, and agent can affect the severity of traffic-related traumas. Therefore, the present study aimed to evaluate the effective factors in severity of these traumas based on Haddon matrix. In the present 1-month cross-sectional study, all the patients injured in traffic accidents, who were referred to the ED of Imam Khomeini and Golestan Hospitals, Ahvaz, Iran, during March 2013 were evaluated. Based on the Haddon matrix, effective factors in accident occurrence were defined in 3 groups of host, agent, and environment. Demographic data of the patients and data regarding Haddon risk factors were extracted and analyzed using SPSS version 20. 700 injured people with the mean age of 29.66 ± 12.64 years (3-82) were evaluated (92.4% male). Trauma mechanism was car-pedestrian in 308 (44%) of the cases and car-motorcycle in 175 (25%). 610 (87.1%) cases were traffic accidents and 371 (53%) occurred in the time between 2 pm and 8 pm. Violation of speed limit was the most common violation with 570 (81.4%) cases, followed by violation of right-of-way in 57 (8.1%) patients. 59.9% of the severe and critical injuries had occurred on road accidents, while 61.3% of the injuries caused by traffic accidents were mild to moderate (p accidents (p severity of traffic accident-related traumas were age over 50, not using safety tools, and undertaking among host-related factors; insufficient environment safety, road accidents and time between 2 pm and 8 pm among environmental factors; and finally, rollover, car-pedestrian, and motorcycle-pedestrian accidents among the agent factors.

Radiation accident at the South Urals in 1957

International Nuclear Information System (INIS)

Nikipelov, B.V.; Romanov, G.N.; Buldakov, L.A.; Babaev, N.S.; Kholina, Yu.B.; Mikerin, E.I.

1989-01-01

Radiation accidents with release of radioactive substances into environment which took place in the South Ural in 1957 is evaluated. Scientific researches conducted since 1957 are described. Scientific data of unique fundamental and applied value were obtaibed. Recommendations for the organization and content of radiation sanctuary are developed. Scientific researches permitted to make reliable long-turm prediction of radiation situation developed owing to the Chernobyl NPP accident and to work out practical recommendations so as to reduce adverse aftereffects of the accident

An assessment of the radiological consequences of releases to groundwater following a core-melt accident at the Sizewell PWR

International Nuclear Information System (INIS)

Maul, P.R.

1984-03-01

In the extremely unlikely event of a degraded core accident at the proposed Sizewell PWR it is theoretically possible for the core to melt through the containment, after which activity could enter groundwater directly or as a result of subsequent leaching of the core in the ground. The radiological consequences of such an event are analysed and compared with the analysis undertaken by the NRPB for the corresponding releases to atmosphere. It is concluded that the risks associated with the groundwater route are much less important than those associated with the atmospheric route. The much longer transport times in the ground compared with those in the atmosphere enable countermeasures to be taken, if necessary, to restrict doses to members of the public to very low levels in the first few years following the accident. The entry of long-lived radionuclides into the sea over very long timescales results in the largest contribution to population doses, but these are delivered at extremely low dose rates which would be negligible compared with background exposure. (author)

Parametric study of a reactivity accident in a pressurized water reactor: control rod cluster ejection

International Nuclear Information System (INIS)

Chesnel, A.

1985-01-01

This research thesis concerns a class 4 accident in a PWR: the ejection of a control rod cluster from the reactor core. It aims at defining, for such an accident, the envelope values which relate the reactivity to the hot spot factor within the frame of a mode A control. The report describes the physical phenomena and their modelling during the considered transient. It presents a simple mathematical solution of the accident which shows that the main neutron parameters are the released reactivity, the delayed neutron fraction, the Doppler coefficient, and the hot spot factor. It reports a temperature sensitivity study, and discusses three-dimensional calculations of irradiation distributions

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

The Tokai-mura JCO criticality accident and the activities of the accident countermeasure support team of Electric Power Companies, Japan

International Nuclear Information System (INIS)

Ogawa, Junko

2000-01-01

A criticality accident occurred at the JCO Tokai-mura nuclear fuel processing plant on September 30, 1999. This accident brought the damages which were unrivaled in the history of atomic energy development in Japan, seriously influencing the citizen life to such an extent as requesting for 320,000 inhabitants within 10 kilometers radius to stay indoors for as long as 18 hours. However, it could be said that though three workers suffered fatal injuries, no substantial hazards were made upon the regional inhabitants due to little release of radioactive substances. This video recorded the activities of the Accident Countermeasure Support Team of the Electric Power Companies immediately after the accident occurred, showing the chronological overview of the particulars of the accident. (author)

Filtra-MVSS mitigates the consequences of a severe reactor accident

International Nuclear Information System (INIS)

Lindau, L.; Gustavsson, L.; Elisson, K.

1989-01-01

The purpose of the filter system, known as Filtra-MVSS (for Multi-Venturi Scrubber System) is to provide pressure relief for the reactor containment and to limit radioactive releases in the event of a reactor accident, thereby largely preventing local radioactive fall-out. To this end the pressure is reduced in a controlled manner and the discharged steam and gases are washed in a multi-venturi scrubber before release. The system is flexible and can cope with a number of hypothetical accident scenarios

Safety analysis of RA reactor operation, I-III, Part III - Environmental effect of the maximum credible accident

International Nuclear Information System (INIS)

Raisic, N.

1963-02-01

Maximum credible accident at the RA reactor would consider release of fission products into the environment. This would result from fuel elements failure or meltdown due to loss of coolant. The analysis presented in this report assumes that the reactor was operating at nominal power at the moment of maximum possible accident. The report includes calculations of fission products activity at the moment of accident, total activity release during the accident, concentration of radioactive material in the air in the reactor neighbourhood, and the analysis of accident environmental effects

Modelling the release of volatile fission product cesium from CANDU fuel under severe accident conditions using artificial neural networks

International Nuclear Information System (INIS)

Andrews, W.S.; Lewis, B.J.; Cox, D.S.

1997-01-01

An artificial neural network (ANN) model has been developed to predict the release of volatile fission products from CANDU fuel under severe accident conditions. The model was based on data for the release Of 134 Cs measured during three annealing experiments (Hot Cell Experiments 1 and 2, or HCE- 1, HCE-2 and Metallurgical Cell Experiment 1, or MCE- 1) at Chalk River Laboratories. These experiments were comprised of a total of 30 separate tests. The ANN established a correlation among 14 separate input variables and predicted the cumulative fractional release for a set of 386 data points drawn from 29 tests to a normalized error, E n , of 0.104 and an average absolute error, E abs , of 0.064. Predictions for a blind validation set (test HCE2-CM6) had an E n of 0.064 and an E abs of 0.054. A methodology is presented for deploying the ANN model by providing the connection weights. Finally, the performance of an ANN model was compared to a fuel oxidation model developed by Lewis et al. and to the U.S. Nuclear Regulatory Commission's CORSOR-M. (author)

Containment and release management

International Nuclear Information System (INIS)

Lehner, J.R.; Pratt, W.T.

1988-01-01

Reducing the risk from potentially severe accidents by appropriate accident management strategies is receiving increased attention from the international reactor safety community. Considerable uncertainty still surrounds some of the physical phenomena likely to occur during a severe accident. The USNRC, in developing its research plan for accident management, wants to ensure that both the developers and implementers of accident management strategies are aware of the uncertainty associated with the plant operators' ability to correctly diagnose an accident, as well as the uncertainties associated with various preventive and mitigative strategies. The use of a particular accident management strategy can have both positive and negative effects on the status of a plant and these effects must be carefully weighed before a particular course of action is chosen and implemented. By using examples of severe accident scenarios, initial insights are presented here regarding the indications plant operators may have to alert them to particular accident states. Insights are also offered on the various management actions operators and plant technical staff might pursue for particular accident situations and the pros and cons associated with such actions. The examples given are taken for the most part from the containment and release phase of accident management, since this is the current focus of the effort in the accident management area at Brookhaven National Laboratory. 2 refs

The consequences of the Chernobyl nuclear accident in Greece

International Nuclear Information System (INIS)

1986-07-01

In this report the radioactive fallout on Greece from the Chernobyl nuclear accident is described. The flow pattern to Greece of the radioactive materials released, the measurements performed on environmental samples and samples of the food chain, as well as some estimations of the population doses and of the expected consequences of the accident are presented. The analysis has shown that the radiological impact of the accident in Greece can be considered minor. (J.K.)

Work-Related Accidents and Sharp Injuries in Paramedics-Illustrated with an Example of a Multi-Specialist Hospital, Located in Central Poland.

Science.gov (United States)

Garus-Pakowska, Anna; Szatko, Franciszek; Ulrichs, Magdalena

2017-08-10

(1) Background: An analysis of work-related accidents in paramedics in Poland by presenting the model and trend of accidents, accident rates and by identifying causes and results of accidents; (2) Methods: A retrospective analysis of medical documentation regarding work-related accidents in a multi-specialist hospital, located in central Poland, in the period 2005-2015. The study group included paramedics who had an accident while being on duty; (3) Results: According to hospital records, 88 paramedics were involved in 390 accidents and 265 injuries caused by sharp instruments. The annual accident rate was 5.34/100 employed paramedics. Most of the accidents occurred at night. The most common reason for the accident was careless behaviour of the paramedic, which resulted in joint sprains and dislocations. Injuries accounted for a huge portion of the total number of events. As many as 45% of injuries were not officially recorded; (4) Conclusion: High rates of work-related accidents and injuries caused by sharp instruments in paramedics are a serious public health problem. Further studies should be conducted in order to identify risk factors of accidents, particularly injuries, and to implement preventative programmes, aiming to minimise rates of occupational hazards for paramedics.

[Proposal of a method for collective analysis of work-related accidents in the hospital setting].

Science.gov (United States)

Osório, Claudia; Machado, Jorge Mesquita Huet; Minayo-Gomez, Carlos

2005-01-01

The article presents a method for the analysis of work-related accidents in hospitals, with the double aim of analyzing accidents in light of actual work activity and enhancing the vitality of the various professions that comprise hospital work. This process involves both research and intervention, combining knowledge output with training of health professionals, fostering expanded participation by workers in managing their daily work. The method consists of stimulating workers to recreate the situation in which a given accident occurred, shifting themselves to the position of observers of their own work. In the first stage of analysis, workers are asked to show the work analyst how the accident occurred; in the second stage, the work accident victim and analyst jointly record the described series of events in a diagram; in the third, the resulting record is re-discussed and further elaborated; in the fourth, the work accident victim and analyst evaluate and implement measures aimed to prevent the accident from recurring. The article concludes by discussing the method's possibilities and limitations in the hospital setting.

Occupational accident and disease claims, work-related stress and job satisfaction of physiotherapists.

Science.gov (United States)

Brattig, Birte; Schablon, Anja; Nienhaus, Albert; Peters, Claudia

2014-01-01

Physiotherapists are exposed to diverse occupational demands. Until now, little has been known about the interaction between occupational stress and the job satisfaction of physiotherapists. This paper aims to examine their work-related stress and job satisfaction. It will analyse accidents at work and occupational diseases of physiotherapists along with work-related physical and psychosocial stress and job satisfaction. We analysed routine data of the German Institute for Statutory Accident Insurance and Prevention in the Health and Welfare Services (BGW) on accidents at work and occurring en route to/from work as well as occupational diseases of physiotherapists. Work-related stress and job satisfaction were examined in a cross-sectional survey using a standard questionnaire to be completed by subjects themselves. Between 2007 and 2011, 1,229 cases of occupational disease were reported to the BGW. The majority of reports involved skin diseases (73%). Stumbles and falls were the most frequent causes of accidents at work (42.9%). Eighty-five physiotherapists all over Germany took part in the survey. They experience high quantitative demands at work. The main physical demands consist of a torso posture between 45° and 90° and high hand activity. Of the 85 subjects, 51% suffer from complaints of the musculoskeletal system in the neck and thoracic spine area and 24% have skin diseases. Most physiotherapists (88%) are satisfied with their work overall. This is aided by a high degree of influence on their work and breaks, by practical application of skills and expert knowledge, high regard for their profession, varied work and a good atmosphere at work. Reservations tend to be about statutory regulations and the social benefits provided by the German healthcare system. Overall, despite high demands and stress relating to the adequacy of resources, the majority of physiotherapists surveyed seem to be satisfied with their job. The main focus of action to promote the

The radiation accident at Institute for Energy Technology Sept. 1982. Some technical considerations

International Nuclear Information System (INIS)

Berteig, L.; Flatby, J.

1985-01-01

On September 2, 1982 a radiation accident with overexposure of one person happened at the gamma irradiation plant at Institute for Energy Technology, Kjeller, Norway. This person died from the radiation injury 13 days later. In the report reference is made to the work of different groups and bodies in connection with the accident. An analysis of the causes of the accident is given. For admittance control to the irradiation area there were generally two independent door interlock systems, one irradiation source position related and the other radiation related. The latter was dismantled for repair at the time of the accident. A micro-switch failure left the source in an unshielded position, initiated a green light on the control panel and released the interlock system of the door. According to working instructions a mobile radiation monitor should have been checked for proper function and carried by anyone entering the irradiation room. This seems not to have been carried out correctly. The conditions set forth for the restarting of the irradiation plant are presented. (orig./HP)

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

Science.gov (United States)

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

2012-09-01

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

Consequence of potential accidents in heavy water plants

International Nuclear Information System (INIS)

Croitoru, C.; Lazar, R.E.; Preda, I.A.; Dumitrescu, M.

1998-01-01

Heavy water plants realize the primary isotopic concentrations of water using H 2 O-H 2 S chemical exchange and they are chemical plants. As these plants are handling and spreading large quantities of hydrogen sulphide (high toxic, corrosive, flammable and explosive as) maintained in the process at relative high temperatures and pressures, it is required an assessing of risks associated with the potential accidents. The H 2 S released in atmosphere as a result of an accident will have negative consequences to property, population and environment. This paper presents a model of consequences quantitative assessment and its outcome for the most dangerous accident in heavy water plants. Several states of the art risk based methods were modified and linked together to form a proper model for this analyse. Five basic steps to identify the risks involved in operating the plants are followed: hazard identification, accident sequence development, H 2 S emissions calculus, dispersion analyses and consequences determination. A brief description of each step and some information of analysis results are provided. The accident proportions, the atmospheric conditions and the population density in the respective area were accounted for consequences calculus. The specific results of the consequences analysis allow to develop the plant's operating safety requirements so that the risk remain at an acceptable level. (authors)

Preparation of hospitals for handling victims of radiation accidents

International Nuclear Information System (INIS)

Vince, M.A.

1985-01-01

This chapter is devoted to a generalized discussion of the inter-and intraorganizational structure of hospitals for handling radiation emergencies of the kind suggested above as well as the isolated remote minor accident involving radiation. The general elements of hospital planning for radiation accidents have been discussed and a detailed protocol for handling the radioactive patient is presented. Minor additions and emphasis to parts of these earlier works are summarized, reflecting experiences gained in receiving simulated radioactively contaminated victims in drills at St. Luke's Hospital of Bethlehem, Pennsylvania. Two accidents were simulated involving mock radioactive materials over a two year period. One such ''accident'' was staged at A-B-E Airport, Lehigh County, in 1981 and the other in the Saucon Valley in 1983. It should be mentioned that in neither case was the release of radioactive material possible, in reality, as portrayed. In planning mock radiation accident drills for emergency care units and support staff, one is best-advised not to pay too much attention to the logic of how the release occurred but rather that there are victims who must be treated, decontaminated and evaluated for the necessity of continued medical care

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

Energy Technology Data Exchange (ETDEWEB)

Peterson, S

2007-08-15

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

Severe accident source term reassessment

International Nuclear Information System (INIS)

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

1987-01-01

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

Monte Carlo simulation of single accident airport risk profile

Science.gov (United States)

1979-01-01

A computer simulation model was developed for estimating the potential economic impacts of a carbon fiber release upon facilities within an 80 kilometer radius of a major airport. The model simulated the possible range of release conditions and the resulting dispersion of the carbon fibers. Each iteration of the model generated a specific release scenario, which would cause a specific amount of dollar loss to the surrounding community. By repeated iterations, a risk profile was generated, showing the probability distribution of losses from one accident. Using accident probability estimates, the risks profile for annual losses was derived. The mechanics are described of the simulation model, the required input data, and the risk profiles generated for the 26 large hub airports.

Developing a relativities approach to valuing the prevention of non-fatal work-related accidents and ill health.

Science.gov (United States)

Karnon, Jonathan; Tsuchiya, Aki; Dolan, Paul

2005-11-01

The aim of the current explorative study is to define and test a process for the valuation of the benefits associated with the prevention of non-fatal work-related accidents and ill health. A relativities approach is adopted, and monetary values for the prevention of three forms of work-related illness are estimated. The approach involves describing relevant attributes of alternative events (accidents or occurrences of ill health), their causes, the characteristics of the relevant working population, and the number of events that are avoidable, and asking respondents to make pair wise choices between alternatives options for prevention. Indirect monetary valuations are obtained against a peg event for which a reliable valuation exists (road deaths).A series of discussion groups were held to identify relevant factors affecting potential valuations and to test the presentation of information. The predicted magnitude of responses for three-case study events (and road deaths) was estimated in a pilot study. These preliminary stages informed the final survey instrument that described five attributes in addition to a statement of the event and occupation, and the likely intervention effect, which was administered by post. Based on a small sample, the results show that virtually all respondents passed the inserted consistency test. The median respondent altered their choice according to the number of events avoided for all three comparisons, such that the estimated valuations appear sensible. Potential amendments are suggested, but the general relativities approach warrants further investigation for the valuation of non-fatal work-related accidents and ill health.

Strategy-oriented display concept to assist severe accident management

International Nuclear Information System (INIS)

Jeong, Kwangsub; Ha, Jaejoo

2000-01-01

The Critical Function Monitoring System (CFMS) is a typical Safety Parameter Display System (SPDS) to assist the operation of Korean Standard Nuclear Power Plants during normal and emergency operation, and SPDS for severe accident is being developed in Korea. When the existing CFMS is used under a severe accident situation, some problems are expected from: (1) different design basis, i.e. prevention of core melt vs. protection of radiation release to environment, (2) different parameters for decision-making, and (3) different domain and depth of information to restore the plant. To resolve the above problems, a concept, 'Strategy-Oriented Information Display' concept, for displaying information for severe accident management is developed in this paper. Whereas the existing SPDS structure is based on the critical safety function, the developed concept is based on the severe accident management strategy. The display for each strategy includes the plant parameters to check the status of plant and component with the logical or graphical views necessary for executing the strategy. As the application of the proposed concept, KAERI is developing a display system, the prototype severe accident SPDS, Severe Accident Management Display System (SAMDIS), to assist plant personnel for executing Korean Severe Accident Management Guidelines. CFMS is developed for a general display suitable to all situations with various displays. On the contrary, SAMDIS provides all the relevant information on one screen based on the proposed concept. The SAMDIS screen shows more extensive area than CFMS and thus plant personnel can recognize the overall plant status at a glance. This concept is quite effective when used with severe accident management guidelines because of the relatively macroscopic characteristics of a severe accident management strategy. (author)

Plutonium emission from the Fukushima accident

Energy Technology Data Exchange (ETDEWEB)

Bossew, P., E-mail: pbossew@bfs.de [German Federal Office for Radiation Protection, Berlin (Germany)

2013-07-01

A strong earthquake and subsequent tsunami on 11{sup th} March 2011 initiated a severe accident in units 1 to 4 of Fukushima Dai-ichi nuclear power plant, resulting in substantial releases of radionuclides. While much has since been published 00 environmental contamination and exposure to radio--iodine and radio-caesium, little is known about releases of plutonium and other non-volatile elements. Although the total activities of released {sup 131}I, {sup 134}Cs and {sup 137}Cs are of the same order of magnitude as of the Chernobyl accident in 1986, the contribution of little volatile elements, including Pu, is much smaller in Fukushima fallout. The reason is the different physical nature of the accident sequence which led to a release of some 10{sup -}5% of the core inventories only (to be compared with 3.5% from Chernobyl). In this contribution the available data on Pu in Fukushima fallout will be reviewed. Data sources are mainly reports and press releases by Japanese authorities and a few scientific articles. The mean ratio {sup 239+240}Pu: {sup 137}Cs in the near field around the NPP (mainly part of Fukushima prefecture and districts of adjacent prefectures) can be assumed about 3 x 10{sup -}7{sup ,} to be compared to nearly 0.01 in the vicinity of Chernobyl, down to about 3 x 10 {sup -6} in Central Europe. Isotopic ratios {sup 238}Pu: {sup 239+240} Pu are about 2.2 (0.46 and 0.035 in Chemobyl and global fallout, respectively). Activity concentrations of Fukushima- {sup 239+240} Pu in surface soil were found up to above 0.1 Bq/kg d.m. in the immediate vicinity of the Fukushima NPP and about one order of magnitude less in Fukushima city, about 60 km away. The {sup 239+240} Pu activity released into the atmosphere is roughly estimated some 10{sup 9} Bq (Chemobyl : almost 10{sup 14} Bq). (author)

Temporal Patterns of Alcohol Consumption and Alcohol-Related Road Accidents in Young Swiss Men: Seasonal, Weekday and Public Holiday Effects.

Science.gov (United States)

Foster, Simon; Gmel, Gerhard; Estévez, Natalia; Bähler, Caroline; Mohler-Kuo, Meichun

2015-09-01

To assess seasonal, weekday, and public holiday effects on alcohol-related road accidents and drinking diaries among young Swiss men. Federal road accident data (35,485 accidents) from Switzerland and drinking diary data from a large cohort of young Swiss men (11,930 subjects) were analysed for temporal effects by calendar week, weekday and public holiday (Christmas, New Years, National Day). Alcohol-related accidents were analysed using rate ratios for observed versus expected numbers of accidents and proportions of alcohol-related accidents relative to the total number. Drinking diaries were analysed for the proportion of drinkers, median number of drinks consumed, and the 90th percentile's number of drinks consumed. Several parallel peaks were identified in alcohol-related accidents and drinking diaries. These included increases on Fridays and Saturdays, with Saturday drinking extending until early Sunday morning, an increase during the summer on workdays but not weekends, an increase at the end of the year, and increases on public holidays and the evening before. Our results suggest specific time-windows that are associated with increases in drinking and alcohol-related harm. Established prevention measures should be enforced during these time-windows to reduce associated peaks. © The Author 2015. Medical Council on Alcohol and Oxford University Press. All rights reserved.

[Health-related consequences of obstructive sleep apnea: daytime sleepiness, accident risk and legal aspects].

Science.gov (United States)

Orth, M; Kotterba, S

2012-04-01

Daytime sleepiness for any reason leads to impairment of daytime performance and an increased accident rate. The consequences are an increase of illness- and accident-related costs for the health system. Obstructive sleep apnea (OSA) is one of the major reasons for increased daytime sleepiness, especially in professional drivers. The accident frequency in OSA can be significantly reduced by adequate continuous positive airway pressure (CPAP) therapy. Up till now there are no uniform legal regulations about the handling of OSAS patients or patients with daytime sleepiness due to other diseases as far as driving ability is concerned.

Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses

Science.gov (United States)

Gold, D. R.; Rogacz, S.; Bock, N.; Tosteson, T. D.; Baum, T. M.; Speizer, F. E.; Czeisler, C. A.

1992-01-01

A hospital-based survey on shift work, sleep, and accidents was carried out among 635 Massachusetts nurses. In comparison to nurses who worked only day/evening shifts, rotators had more sleep/wake cycle disruption and nodded off more at work. Rotators had twice the odds of nodding off while driving to or from work and twice the odds of a reported accident or error related to sleepiness. Application of circadian principles to the design of hospital work schedules may result in improved health and safety for nurses and patients.

Nuclear Reactor RA Safety Report, Vol. 16, Maximum hypothetical accident

International Nuclear Information System (INIS)

1986-11-01

Fault tree analysis of the maximum hypothetical accident covers the basic elements: accident initiation, phase development phases - scheme of possible accident flow. Cause of the accident initiation is the break of primary cooling pipe, heavy water system. Loss of primary coolant causes loss of pressure in the primary circuit at the coolant input in the reactor vessel. This initiates safety protection system which should automatically shutdown the reactor. Separate chapters are devoted to: after-heat removal, coolant and moderator loss; accident effects on the reactor core, effects in the reactor building, and release of radioactive wastes [sr

Joint research project WASA-BOSS: Further development and application of severe accident codes. Assessment and optimization of accident management measures. Project B: Accident analyses for pressurized water reactors with the application of the ATHLET-CD code

International Nuclear Information System (INIS)

Jobst, Matthias; Kliem, Soeren; Kozmenkov, Yaroslav; Wilhelm, Polina

2017-02-01

Within the framework of the project an ATHLET-CD input deck for a generic German PWR of type KONVOI has been created. This input deck was applied to the simulation of severe accidents from the accident categories station blackout (SBO) and small-break loss-of-coolant accidents (SBLOCA). The complete accident transient from initial event at full power until the damage of reactor pressure vessel (RPV) is covered and all relevant severe accident phenomena are modelled: start of core heat up, fission product release, melting of fuel and absorber material, oxidation and release of hydrogen, relocation of molten material inside the core, relocation to the lower plenum, damage and failure of the RPV. The model has been applied to the analysis of preventive and mitigative accident management measures for SBO and SBLOCA transients. Therefore, the measures primary side depressurization (PSD), injection to the primary circuit by mobile pumps and for SBLOCA the delayed injection by the cold leg hydro-accumulators have been investigated and the assumptions and start criteria of these measures have been varied. The time evolutions of the transients and time margins for the initiation of additional measures have been assessed. An uncertainty and sensitivity study has been performed for the early phase of one SBO scenario with PSD (until the start of core melt). In addition to that, a code -to-code comparison between ATHLET-CD and the severe accident code MELCOR has been carried out.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-15

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

Spallation Neutron Source Accident Terms for Environmental Impact Statement Input

Energy Technology Data Exchange (ETDEWEB)

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

1998-08-01

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

Diffusion modeling of fission product release during depressurized core conduction cooldown conditions

International Nuclear Information System (INIS)

Martin, R.C.

1991-01-01

A simple model for diffusion through the silicon carbide layer of TRISO particles is applied to the data for accident condition testing of fuel spheres for the High-Temperature Reactor program of the Federal Republic of Germany (FRG). Categorization of sphere release of 137 Cs based on fast neutron fluence permits predictions of release with an accuracy comparable to that of the US/FRG accident condition fuel performance model. Calculations are also performed for 85 Kr, 90 Sr, and 110m Ag. Diffusion of cesium through SiC suggests that models of fuel failure should consider fuel performance during repeated accident condition thermal cycling. Microstructural considerations in models of fission product release are discussed. The neutron-induced segregation of silicon within the SiC structure is postulated as a mechanism for enhanced fission product release during accident conditions. As oxygen-enhanced SiC decomposition mechanism is also discussed. (author). 12 refs, 11 figs, 2 tabs

Assessment of work-related accidents associated with waste handling in Belo Horizonte (Brazil).

Science.gov (United States)

Mol, Marcos Pg; Pereira, Amanda F; Greco, Dirceu B; Cairncross, Sandy; Heller, Leo

2017-10-01

As more urban solid waste is generated, managing it becomes ever more challenging and the potential impacts on the environment and human health also become greater. Handling waste - including collection, treatment and final disposal - entails risks of work accidents. This article assesses the perception of waste management workers regarding work-related accidents in domestic and health service contexts in Belo Horizonte, Brazil. These perceptions are compared with national data from the Ministry of Social Security on accidents involving workers in solid waste management. A high proportion of accidents involves cuts and puncture injuries; 53.9% among workers exposed to domestic waste and 75% among those exposed to health service waste. Muscular lesions and fractures accounted for 25.7% and 12.5% of accidents, respectively. Data from the Ministry of Social Security diverge from the local survey results, presumably owing to under-reporting, which is frequent in this sector. Greater commitment is needed from managers and supervisory entities to ensure that effective measures are taken to protect workers' health and quality of life. Moreover, workers should defend their right to demand an accurate registry of accidents to complement monitoring performed by health professionals trained in risk identification. This would contribute to the improved recovery of injured workers and would require managers in waste management to prepare effective preventive action.

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

International Nuclear Information System (INIS)

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

1988-03-01

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

Work-Related Accidents and Sharp Injuries in Paramedics—Illustrated with an Example of a Multi-Specialist Hospital, Located in Central Poland

Science.gov (United States)

Szatko, Franciszek; Ulrichs, Magdalena

2017-01-01

(1) Background: An analysis of work-related accidents in paramedics in Poland by presenting the model and trend of accidents, accident rates and by identifying causes and results of accidents; (2) Methods: A retrospective analysis of medical documentation regarding work-related accidents in a multi-specialist hospital, located in central Poland, in the period 2005–2015. The study group included paramedics who had an accident while being on duty; (3) Results: According to hospital records, 88 paramedics were involved in 390 accidents and 265 injuries caused by sharp instruments. The annual accident rate was 5.34/100 employed paramedics. Most of the accidents occurred at night. The most common reason for the accident was careless behaviour of the paramedic, which resulted in joint sprains and dislocations. Injuries accounted for a huge portion of the total number of events. As many as 45% of injuries were not officially recorded; (4) Conclusion: High rates of work-related accidents and injuries caused by sharp instruments in paramedics are a serious public health problem. Further studies should be conducted in order to identify risk factors of accidents, particularly injuries, and to implement preventative programmes, aiming to minimise rates of occupational hazards for paramedics. PMID:28796193

Models selected for calculation of doses, health effects and economic costs due to accidental radionuclide releases from nuclear power plants. Technical report

International Nuclear Information System (INIS)

Strenge, D.L.; Acharya, S.; Baker, D.A.; Droppo, J.G.; McPherson, R.B.

1980-05-01

Models are described for use in site-specific environmental consequence analysis of nuclear reactor accidents of Classes 3 through 9. The models presented relate radioactivity released to resulting doses, health effects, and costs of remedial actions. Specific models are presented for the major exposure pathways of airborne releases, waterborne releases and direct irradiation from activity within the facility buildings, such as the containment. Time-dependent atmospheric dispersion parameters, crop production parameters, and other variable parameters are used in the models. The environmental effects are analyzed for several accident start times during the year. Several remedial actions are considered

Semi-passive pad (post-accident dilution) system combined with recombiners or igniters for e.g., multiple-unit VVER

International Nuclear Information System (INIS)

Eckardt, B.A.

1997-01-01

In order to reduce the risk associated with hypothetical severe nuclear accidents, it has been necessary to develop means for hydrogen control which are capable of handling high H 2 production rates of several m 3 /s. These systems and components should be of simple and, as far as possible, passive design. Moreover, their efficiency must not be affected by the H 2 production scenario. To meet these requirements, Siemens has supplemented its dual process for hydrogen reduction using recombiners and igniters by developing a new process: the semi-passive Post-Accident Dilution (PAD) System. The objective of the work presented in this paper was to design an alternative approach for hydrogen control comprising post-accident CO 2 dilution combined with recombiners or igniters for postulated severe accidents that result in significant hydrogen releases. The combined technique was to keep the dynamic loads arising inside the containment to within a range of only a few millibars, even in the event of transient hydrogen release and distribution processes accompanied by combustion, and was thus to prevent any hazard for safety-related equipment. (author)

Support for Nuclear Explosive Safety Division, Department of Energy, Albuquerque Operations. Effects of a postulated uranium transportation accident

International Nuclear Information System (INIS)

Just, R.A.

1997-10-01

Transportation System Risk Assessments (TSRAs) document the degree of compliance of proposed DOE shipments of nuclear components with applicable federal regulations and the risk associated with the proposed shipments. TSRAs must often evaluate the consequences of possible transportation accidents involving uranium. If a relatively simple bounding analysis can show that the consequences resulting from a worst case scenario are acceptably low, a more time intensive and costly risk analysis can be avoided. A bounding consequence analysis has been prepared for a worst case noncriticality transportation accident involving the shipment of uranium. In the absence of a criticality incident, a fire or explosion are the only plausible mechanisms identified for dispersing significant amounts of solid hazardous material. Therefore, three very conservative bounding accidents are considered: (1) analysis of the postulated direct radiation exposure, (2) the airborne release of uranium due to a fire, and (3) the release of uranium into a waterway and uptake into drinking water. This report provides the equations, assumptions, and reference information used to predict the consequences of possible transportation accidents involving natural, depleted, and highly enriched uranium

The Chernobyl accident and its consequences.

Science.gov (United States)

Saenko, V; Ivanov, V; Tsyb, A; Bogdanova, T; Tronko, M; Demidchik, Yu; Yamashita, S

2011-05-01

The accident at the Chernobyl nuclear power plant was the worst industrial accident of the last century that involved radiation. The unprecedented release of multiple different radioisotopes led to radioactive contamination of large areas surrounding the accident site. The exposure of the residents of these areas was varied and therefore the consequences for health and radioecology could not be reliably estimated quickly. Even though some studies have now been ongoing for 25 years and have provided a better understanding of the situation, these are yet neither complete nor comprehensive enough to determine the long-term risk. A true assessment can only be provided after following the observed population for their natural lifespan. Here we review the technical aspects of the accident and provide relevant information on radioactive releases that resulted in exposure of this large population to radiation. A number of different groups of people were exposed to radiation: workers involved in the initial clean-up response, and members of the general population who were either evacuated from the settlements in the Chernobyl nuclear power plant vicinity shortly after the accident, or continued to live in the affected territories of Belarus, Russia and Ukraine. Through domestic efforts and extensive international co-operation, essential information on radiation dose and health status for this population has been collected. This has permitted the identification of high-risk groups and the use of more specialised means of collecting information, diagnosis, treatment and follow-up. Because radiation-associated thyroid cancer is one of the major health consequences of the Chernobyl accident, a particular emphasis is placed on this malignancy. The initial epidemiological studies are reviewed, as are the most significant studies and/or aid programmes in the three affected countries. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights

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

Preliminary investigations of the significance of the ingestion pathway following accidental releases with actinides

International Nuclear Information System (INIS)

Steinhauer, C.

1985-10-01

Preliminary accident consequence assessments have been performed with the computer code UFOMOD to study the significance of the ingestion pathway in accidental releases with actinides. The investigation was based on the release category K1 of the 'Risk Oriented Analysis of the SNR 300', in which a higher fraction of actinides is released than in the worst release category for an LWR. The analysis was carried out using the currently implemented food chain transport model WASH-1400/BSU and data from the dynamic model from the MARC methodology. To study the influence of the time of the accident on the food chain-related results, releases in January and July were considered by means of the MARC data. In this report the differences are presented between both food chain transport models for transuranium elements and those which are observed in the potential doses due to ingestion, the areas affected by food-bans and the late health effects when using both models and taking the influence of the season into account. (orig./HP) [de

Chernobyl reactor accident

International Nuclear Information System (INIS)

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

1986-01-01

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

Radiation doses from contaminated food after a nuclear accident

International Nuclear Information System (INIS)

Nielsen, S.P.; Oehlenschlaeger, M.

1991-03-01

This report presents estimates of radiation doses from contaminated food after a hypothetical accident at a nuclear power plant. The calculations are made from assumptions intended to represent Swedish conditions. The accident scenario is based on a hypothetical core melt in a nuclear power reactor followed by a release to the atmosphere of iodine and caesium corresponding to 0.6% of the Forsmark unit 3 core inventory. The results are expressed in terms of average effective doses from contaminated food to individuals in the critical group living near the power plant, 2 km from the point of release, and living from locally produced foodstuffs. The calculations are made for a winter release and a summer release, and for dry and rainy conditions. Dynamic radioecological models are used, which have been developed from Danish experience with readioactive fallout from nuclear weapons testing and with fallout from the Chernobyl accident. The accidental release is estimated to cause doses in the summer season from 131 I of circa 200 mSv to children and circa 30 mSv to adults based on a deposition during dry conditions of 11 MBq 131 I m -2 . The dosed from 134 Cs and 137 Cs are estimated at circa 20 mSv to children and adults in case of winter release and circa 160 mSv in case of summer release based on a deposition during dry conditions of 0.5 MBQ 134 Cs and 0.4 MBq 137 Cs m -2 . The main reason for the large difference between the winter and the summer releases is the high sensitivity of cerals to direct contamination on month prior to harvest. In case of precipitation the doses are estimated at twice those for dry conditons. (author) 8 tabs., 16 ills., 13 refs

Accident analysis for transuranic waste management alternatives in the U.S. Department of Energy waste management program

International Nuclear Information System (INIS)

Nabelssi, B.; Mueller, C.; Roglans-Ribas, J.; Folga, S.; Tompkins, M.; Jackson, R.

1995-01-01

Preliminary accident analyses and radiological source term evaluations have been conducted for transuranic waste (TRUW) as part of the US Department of Energy (DOE) effort to manage storage, treatment, and disposal of radioactive wastes at its various sites. The approach to assessing radiological releases from facility accidents was developed in support of the Office of Environmental Management Programmatic Environmental Impact Statement (EM PEIS). The methodology developed in this work is in accordance with the latest DOE guidelines, which consider the spectrum of possible accident scenarios in the implementation of various actions evaluated in an EIS. The radiological releases from potential risk-dominant accidents in storage and treatment facilities considered in the EM PEIS TRUW alternatives are described in this paper. The results show that significant releases can be predicted for only the most severe and extremely improbable accidents sequences

Environmental assessment of the Chernobyl releases in China

International Nuclear Information System (INIS)

Zunsu, H.

1988-01-01

Since Chernobyl accident, China has rapidly developed a program of emergency preparedness for nuclear accidents that the institute of radiation protection assumes the responsibility together with other institutions. For the nuclear power plants in Qinshan and in Daya Bay, a series of emergency preparedness, including the investigation of conditions and feasibility of some principal protective measures are being carried out. The research program includes atmospheric transfer and dispersion, modelling analysis of accident consequence assessment and development of a computer software system for accident consequence prediction. The strategy of China is to well organize all resources and to broaden the international cooperation. The drafting of national emergency regulations and technical guides and the establishment of specialized technical teams are in progress. In China, the accident consequence assessment is based on the specialist experiences from transfer of radioactive effluents in the atmosphere, in water and in ecological system. On May 1986 environmental assessment of the Chernobyl releases in China and environmental monitoring were carried out. Radio-nuclides released from the Chernobyl accident were detectable in all parts of country but the concentrations were very low. The results of the environmental monitoring have been presented. 7 figs., 11 tabs. (author)

MDEP AP1000WG Design-Specific Common Position CP-AP1000WG-02. Common position addressing Fukushima Daiichi NPP accident-related issues

International Nuclear Information System (INIS)

2016-09-01

A severe accident involving several units took place in Japan at Fukushima Daiichi nuclear power plant (NPP) in March 2011. The immediate cause of the accident was an earthquake followed by a tsunami coupled with inadequate provisions against the consequences of such events in the design. Opportunities to improve protection against a realistic design basis tsunami had not been taken. As a consequence of the tsunami, safety equipment and the related safety functions were lost at the plant, leading to core damage in three units and subsequently to large radioactive release. Several studies have already been performed to better understand the accident progression and detailed technical studies are still in progress in Japan and elsewhere. In the meantime, on-going studies on the behaviour of nuclear power plants in very severe situations, similar to Fukushima Daiichi, seek to identify potential vulnerabilities in plant design and operation; to suggest reasonably practicable upgrades; or to recommend enhanced regulatory requirements and guidance to address such situations. Likewise, agencies around the world that are responsible for regulating the design, construction and operation of AP1000 R plants are engaged in similar activities. The MDEP AP1000 R Working Group (AP1000 WG) members consist of members from Canada, China, the United Kingdom and the United States. Since the regulatory review of their AP1000 R applications have not been completed by all of these Countries yet, this paper identifies common preliminary approaches to address potential safety improvements for AP1000 R plants as related to lessons learned from the Fukushima Daiichi accident or Fukushima Daiichi-related issues. In seeking common position, regulators will provide input to this paper to reflect their safety conclusions regarding the AP1000 R design and how the design could be enhanced to address Fukushima Daiichi issues. The common preliminary approaches are organized into five sections

Decision support system for containment and release management

Energy Technology Data Exchange (ETDEWEB)

Oosterhuis, B [Twente Univ., Enschede (Netherlands). Computer Science Dept.

1995-09-01

The Containment and Release Management project was carried out within the Reinforced Concerted Action Programme for Accident Management Support and partly financed by the European Union. In this report a prototype of an accident management support system is presented. The support system integrates several concepts from accident management research, like safety objective trees, severe accident phenomena, calculation models and an emergency response data system. These concepts are provided by the prototype in such a way that the decision making process of accident management is supported. The prototype application is demonstrated by process data taken from a severe accident scenario for a pressurized water reactor (PWR) that was simulated with the thermohydraulic computer program MAAP. The prototype was derived from a decision support framework based on a decision theory. For established and innovative concepts from accident management research it is pointed out in which way these concepts can support accident management and how these concepts can be integrated. This approach is generic in two ways; it applies to both pressurized and boiling water reactors and it applies to both in vessel management and containment and release management. The prototype application was developed in Multimedia Toolbox 3.0 and requires at least a 386 PC with 4 MB memory, 6 MB free disk space and MS Windows 3.1. (orig.).

Decision support system for containment and release management

International Nuclear Information System (INIS)

Oosterhuis, B.

1995-09-01

The Containment and Release Management project was carried out within the Reinforced Concerted Action Programme for Accident Management Support and partly financed by the European Union. In this report a prototype of an accident management support system is presented. The support system integrates several concepts from accident management research, like safety objective trees, severe accident phenomena, calculation models and an emergency response data system. These concepts are provided by the prototype in such a way that the decision making process of accident management is supported. The prototype application is demonstrated by process data taken from a severe accident scenario for a pressurized water reactor (PWR) that was simulated with the thermohydraulic computer program MAAP. The prototype was derived from a decision support framework based on a decision theory. For established and innovative concepts from accident management research it is pointed out in which way these concepts can support accident management and how these concepts can be integrated. This approach is generic in two ways; it applies to both pressurized and boiling water reactors and it applies to both in vessel management and containment and release management. The prototype application was developed in Multimedia Toolbox 3.0 and requires at least a 386 PC with 4 MB memory, 6 MB free disk space and MS Windows 3.1. (orig.)

Sellafield (release of radioactivity)

Energy Technology Data Exchange (ETDEWEB)

Cunningham, J; Goodlad, A; Morris, M

1986-02-06

A government statement is reported, about the release of plutonium nitrate at the Sellafield site of British Nuclear Fuels plc on 5 February 1986. Matters raised included: details of accident; personnel monitoring; whether radioactive material was released from the site; need for public acceptance of BNFL activities; whether plant should be closed; need to reduce level of radioactive effluent; number of incidents at the plant.

Effectiveness of cleanup criteria relative to an accidental nuclear release

International Nuclear Information System (INIS)

Chen, S.Y.; Yuan, Y.C.

1988-01-01

In the event of an accidental nuclear release, the associated long-term radiological risks would result primarily from ground contamination pathways. Cleanup of the contaminated ground surfaces is a necessary step toward reducing the radiological risk to the general population. Ideally, the radiological risk decreases as the level of cleanup effort increases; however, as the cleanup criterion (i.e., the required contaminant concentration after cleanup) becomes more stringent, the cleanup effort may become prohibitively costly. This study examines several factors that are important in determining the effectiveness of the cleanup criteria for selected radionuclides: (a) annual individual dose commitment (mrem/yr), (b) total population environmental dose commitment (person-rem), and (c) total area (km 2 ) requiring cleanup following an accident. To effectively protect the general population, the benefits of cleanup should be weighed against the potentially large increase in cleanup area (and the associated costs) as the cleanup criterion becomes more stringent. The effectiveness of cleanup will vary, depending largely on site-specific parameters such as population density and agricultural productivity as well as on the amount and type of radionuclide released. Determination of an optimum cleanup criterion should account for all factors, including a comprehensive cost/benefit analysis

Implementation of hydrogen mitigation techniques during severe accidents in nuclear power plants

International Nuclear Information System (INIS)

1996-01-01

concentration and under special geometric conditions, an accelerated flame or even a local detonation may occur which would produce higher dynamic loads than a deflagration and a more serious threat to equipment and structures. Should it occur in spite of its low probability, a global detonation, following prolonged and extensive accumulation of hydrogen in the containment atmosphere, would be a major threat to the containment integrity. The goal of hydrogen mitigation techniques is to prevent loads, resulting from hydrogen combustion, which could threaten containment integrity. The risk of containment failure depends on the overall hydrogen concentration which is dependent on the amount of hydrogen released and the containment volume. A possible containment failure also depends on the containment structure and design which is very important in the resistance of the containment to a global combustion. Geometrical sub-compartmentalization is also very important, because significant amounts of hydrogen could accumulate in compartments to create high local concentrations of hydrogen that could be well within the detonability limits. Once accident management measures aimed at preventing severe accidents from occurring have failed and hydrogen is being generated and released to the containment atmosphere in large amounts, the first step is to reduce the possibility of hydrogen accumulating to flammable concentrations. Where flammable concentrations cannot be precluded, the next step is to minimize the volume of gas at flammable concentrations and the third and last step is to prevent further increasing hydrogen levels from the flammable to detonable mixture concentrations. The purpose of this paper is to present a snapshot, from a technical viewpoint, of the current situation regarding the implementation of hydrogen mitigation techniques for severe accident conditions in nuclear power plants. Broader aspects related to overall accident management policies are not considered here

Identification and assessment of containment and release management strategies

International Nuclear Information System (INIS)

Lehner, J.R.; Lin, C.C.; Neogy, P.

1993-01-01

Brookhaven National Laboratory, under the auspices of the U.S. Nuclear Regulatory Commission, is investigating accident management strategies which could help preserve containment integrity or minimize the release of radioactivity during a severe accident in a nuclear reactor. The objective is to make use of existing plant systems and equipment in innovative ways to reduce the likelihood of containment failure or to mitigate the release of fission products to the environment if failure cannot be prevented. Many of these strategies would be implemented during the later stages of a severe accident, i.e. after the molten core penetrates the reactor vessel. Significant uncertainties exist regarding some of the phenomena involved with this phase of a severe accident. The identification and assessment process for containment and release strategies is described, and some insights derived from its application to a BWR Mark I plant are presented. A station blackout accident for this kind of plant is considered. The challenges encountered are identified and existing emergency guidelines are reviewed, where needed and when possible, new strategies are devised. The feasibility and effectiveness of these new strategies are assessed, making due allowances for the complicated phenomena and associated uncertainties involved. Both beneficial and adverse effects of the suggested strategies are considered. (orig.)

Radiation doses in accidents at sea-transportation of spent fuel

International Nuclear Information System (INIS)

Appelgren, A.; Bergstroem, U.; Devell, L.

1978-01-01

In order to investigate the consequences of shipping accidents, a release of activity is assumed. This report presents the calculations of individual and collective doses from the two most severe postulated accidents which are given in a special accident analysis. One of the accidents is a ship collision together with fire on-board, the ship is floating after the collision and a certain quantity volatile fission products gives airborne activity. In the other case, it is a fire on-board, the ship will sink and cause a certain leakage to the sea

High enrichment to low enrichment core's conversion. Accidents analysis

International Nuclear Information System (INIS)

Abbate, P.; Rubio, R.; Doval, A.; Lovotti, O.

1990-01-01

This work analyzes the different accidents that may occur in the reactor's facility after the 20% high-enriched uranium core's conversion. The reactor (of 5 thermal Mw), built in the 50's and 60's, is of the 'swimming pool' type, with light water and fuel elements of the curve plates MTR type, enriched at 93.15 %. This analysis includes: a) accidents by reactivity insertion; b) accidents by coolant loss; c) analysis by flow loss and d) fission products release. (Author) [es