Accident Emergency Response Research Articles

基于粒子法的熔融物碎片在铅冷却剂内运动行为模拟

研究严重事故工况下堆芯熔融物在一回路内的迁移及分布特性对于制定严重事故缓解措施及应急策略具有一定意义。本文通过定义熔融物颗粒的产生条件、入口速度、重力、粘性力、粒子数密度计算模型，完成粒子法程序MPS中固体颗粒物及铅/铅铋流体计算模型的开发。利用改进后的程序计算Zr-4合金碎片及二氧化铀碎片在不同的冷却剂流速及冷却剂粘性条件下的运动行为，分析熔融物密度、冷却剂流速、冷却剂粘性对熔融物迁移行为的影响，初步验证了应用粒子法开展熔融物运动行为研究的可行性，为后续研究及实验验证提供了基础。 Investigation on the migration and distribution characteristics of the core molten debri in primary loop under severe accident is significant for the development of accident mitigation and emergency response strategies. Solid debris and lead/lead and bismuth calculation model is developed through defining the debri generation conditions, inlet velocity, gravity, viscous force, and particle number density model. Transportation behavior of Zr-4 alloy debri and uranium dioxide in lead coolant under different coolant velocity and viscosity are simulated with modified MPS code; effects of debri density, coolant mass flow rate and viscosity on transportation of debri are analyzed. Feasi-bility of the application of MPS method in the investigation of molten debri transportation behavior in lead coolant is preliminarily verified, which also provides the basis for subsequent further re-search and experimental validation.

GPS & GIS In Road Accident Mapping And Emergency Response Management

Road accidents is a major cause of mortality worldwide with urgent action required to mitigate against the negative impacts. A comprehensive accident recording and analysis system can provide a GISbased solution for control and management of accident events as a real-time monitoring system. This paper presents a GIS approach to road accident management based on spatial autocorrelation. It goes further to analyzing the spatial viability of emergency services offered to the accident victims. The study starts with the identification of the accident prone zones along Waiyaki Way in Nairobi, Kenya using GPS and GIS. For this purpose, the road accident data for the years 2013, 2014 and 2015 pertaining to Waiyaki Way was obtained from the traffic police department and used for analysis. Accident particulars like date, location, number of victims (fatal, serious and slight injuries), classes of victims (drivers, motor cyclists, pedal cyclists, passengers, pedestrians) were included in the GIS database. The “Density” function available in the spatial analyst extension of the Arc GIS software was applied to identify the accident prone areas during the years 2013, 2014 and 2015. Assessment of spatial clustering of accidents and hotspots spatial densities was carried out following Moran‟s I method of spatial autocorrelation, and point Kernel density functions. An effort was made to develop a comprehensive accident information management system that can provide a GIS-based solution for control and management of accident events. This system will inform clients about accident locations, accident and service diagnosis, reducing the number of accidents based on the accident reports thus increasing the level of road safety and fast delivery of emergency services. Keywords; Accidents, GIS, AIMS

A hybrid fuzzy FTA-AHP method for risk decision-making in accident emergency response of work system

This paper focuses on a risk decision making problem in high-risk work system. A special risk decision-making problem with dynamic and risky characteristics needs to be considered in work system which involves many complex factors in safety risks and control measurements. Furthermore, taking into account the inherent imprecision and uncertainty of the available data, a method based on Fuzzy Fault Tree Analysis (FFTA) is proposed to solve the problem. Unlike conventional fuzzy fault tree analysis, the fuzzy analytic hierarchy process is applied to eliminate ambiguity and subjectivity in determining the weights of criteria. Furthermore, a more simple and effective method for ranking fuzzy numbers is introduced to determine the relationships among the fuzzy results. Based on these methods, a hybrid approach is proposed for risk decision-making in accident emergency response of work system. Finally, a case study on the accident of crane hitting the high bent is given to demonstrate the proposed the validity and objectivity of the method. Compared with other available methods in the literature, the results reported here suggest that the hybrid method is more reasonable under the conditions of limited decision data and possible evolvement of emergency states.

Contaminant deposition building shielding factors for US residential structures

This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario from contaminant deposition on the roof and surrounding surfaces. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations from contaminant deposition on the roof and surrounding ground as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement as well for single-wide manufactured housing-unit.

Cloud immersion building shielding factors for US residential structures

This paper presents validated building shielding factors designed for contemporary US housing-stock under an idealized, yet realistic, exposure scenario within a semi-infinite cloud of radioactive material. The building shielding factors are intended for use in emergency planning and level three probabilistic risk assessments for a variety of postulated radiological events in which a realistic assessment is necessary to better understand the potential risks for accident mitigation and emergency response planning. Factors are calculated from detailed computational housing-units models using the general-purpose Monte Carlo N-Particle computational code, MCNP5, and are benchmarked from a series of narrow- and broad-beam measurements analyzing the shielding effectiveness of ten common general-purpose construction materials and ten shielding models representing the primary weather barriers (walls and roofs) of likely US housing-stock. Each model was designed to scale based on common residential construction practices and include, to the extent practical, all structurally significant components important for shielding against ionizing radiation. Calculations were performed for floor-specific locations as well as for computing a weighted-average representative building shielding factor for single- and multi-story detached homes, both with and without basement, as well for single-wide manufactured housing-units.

Modification and Application of Gaussian Plume Model for an Industrial Transfer Park

Applying diffusion model in gas leakage incident consequences analysis could provide favorable technical support and professional assistant method for accident emergency response with great realistic significance for industrial transfer park. The core of analysis lies in the selection and rational use of diffusion model. GPM for continuous released condition with some foundation hypothesis conditions should be modified in practice. Comprehensive amendment was discussed and implemented in this paper based on actual circumstance situation in order to achieve the objective of higher accurater analysis. The improvement successfully enhances the model analysis ability and applicability, which could play a role as an important component in the emergency response system for the parks management.

Nuclear Power Safety Development and Accident Emergency in China

Nuclear power is clean, safe, but not zero risk, which has been evidenced by the history of nuclear power development. Nuclear accident emergency response is the final barrier of depth defense to reduce the potential risks that may arise from nuclear power development, which must be enhanced. The accident emergency preparedness in China and China responses to Fukushima accident are presented. Learning lessons from past nuclear power accidents (the Three Mile Island, Chernobyl and Fukushima), China would be keeping confidence in nuclear power development and advancing further improvement of emergency response capabilities to insist on the safety-first principle for nuclear power development.

Integrating geographical information and augmented reality techniques for mobile escape guidelines on nuclear accident sites

During nuclear accidents, when radioactive materials spread into the environment, the people in the affected areas should evacuate immediately. However, few information systems are available regarding escape guidelines for nuclear accidents. Therefore, this study constructs escape guidelines on mobile phones. This application is called Mobile Escape Guidelines (MEG) and adopts two techniques. One technique is the geographical information that offers multiple representations; the other is the augmented reality that provides semi-realistic information services. When this study tested the mobile escape guidelines, the results showed that this application was capable of identifying the correct locations of users, showing the escape routes, filtering geographical layers, and rapidly generating the relief reports. Users could evacuate from nuclear accident sites easily, even without relief personnel, since using slim devices to access the mobile escape guidelines is convenient. Overall, this study is a useful reference for a nuclear accident emergency response.

Integrating four-dimensional geographical information and mobile techniques into radiological accident emergency response training

When radiological accidents occur, radioactive material may spread into the atmosphere, causing large-scale and long-term contamination. To diminish the effects of such accidents, researchers from many countries have investigated training programs in emergency response to radiological accidents, especially in the wake of several serious radiological accidents. Although many training programs have been proposed, this study identifies two problems: the lack of effective data representation and the lack of complete training records. Therefore, by considering various requirements for relief and evacuation work at radiological accident sites, it integrates four-dimensional geographical information and mobile techniques to construct a training platform for radiological accident emergency response. During training, groups of participants learn to respond to simulated radiological accident scenarios. Moreover, participants can use the training platform to review and discuss training details. Judging by the results, the training platform has not only increased the effectiveness of training programs, but also complied with standard operating procedures for radiological accident emergency response in Taiwan. In conclusion, this study could serve as a useful reference for similar studies and applications.

Research on OREMS-based large-scale emergency evacuation using vehicles

In densely populated urban areas, in the event of the toxic gases leak, how to accurately determine the risky zone and take effective measures to evacuate inhabitants quickly out of dangerous areas and minimize the unexpected losses is a tropical topic in China. First, the ALOHA code defined any interested accidents scenarios. For any different exposure times and concentrations, the distances down wind direction could be determined, which eventually generated the dead zone, wounded zone, injured zone and evacuation zone. Then, it presented the procedure of an emergency evacuation routes selection, the choice of the principle of refuges and shelters for evacuated inhabitants, as well as evacuation traffic organizations, vehicle assignments, real-time communications and other traffic evacuation strategies. Finally, the OREMS code was proposed to study the sudden leak accident and design emergency response policies (ERP). A sudden gaseous leakage incident in Tianjin Olympic stadium was chosen as an example to verify the raw ERP including the evacuation road network design, the evacuation time for vehicles, vehicle running conditions and the possible road congestions. Results showed that when the radium of the emergency evacuation scope is about 3 km, the time for evacuation of 50% vehicles is proper.

BAYER ACCUSED OF SKIRTING SAFETY

A DECISION TO HASTEN the restart of a pesticide production process and bypass safety controls led to a tragic accident on Aug. 28, 2008, at the Bayer CropScience plant in Institute, W.Va., concludes the Chemical Safety & Hazard Investigation Board (CSB), in a report released on Jan. 20. The accident destroyed a key pesticide manufacturing unit, killed two workers, required 40,000 people living near the plant to shelter in place, and revealed gross inadequacies in Bayer’s accident emergency response operations. Workers at the Bayer plant were under pressure to resume production of the pesticides methomyl and Larvin after a lengthy maintenance shutdown, according to the CSB investigation. As a result, they failed to evaluate new computer programs, inspect safety equipment, and conduct safety process checks. Most critical, the report says, was the intentional overriding of an interlock system that was designed to prevent a runaway reaction inside a residue treater pressure vessel. Late at ...

Construction Safety Risk Mitigation

Construction safety and health management has improved significantly following the Occupational Safety and Health Act of 1970. In response to this legislation, contractors began implementing safety programs to reduce occupational safety and health hazards on construction sites. Researchers recently found that the current process of selecting specific elements for a safety program is informal. This paper describes the results of a recent study designed to determine the relative effectiveness of safety program elements by quantifying their individual ability to mitigate construction safety and health risks. In order to determine the effectiveness of individual safety program elements, the following research activities were performed: (1) an appropriate safety risk classification system was created using an aggregation of relevant literature; (2) highly effective safety program elements were identified in literature; and (3) the ability of each safety program element to mitigate a portion of each of the safety risk classes was quantified using the Delphi method. The results of the research indicate that the most effective safety program elements are upper management support and commitment and strategic subcontractor selection and management and the least effective elements are recordkeeping and accident analyses and emergency response planning. It is expected that the data presented in this paper can be used to strategically select elements for a safety program, target specific safety and health risks, and influence resource allocation when funds are limited.

International exchange of emergency phase information and assessments: an aid to national/international decision makers.

This paper discusses a collaborative project (1) to demonstrate the feasibility and benefit of a system seeking early review, in a 'quasi peer review' mode, of nuclear accident plume and dose assessment predictions by four major international nuclear accident emergency response systems before release of calculations to respective national authorities followed by (2) sharing these results with responsible national/international authorities, (3) development of an affordable/accessible system to distribute results to countries without prediction capabilities and (4) utilisation for exercises and collaboration studies. The project exploits Internet browser technology and low-cost PC hardware, incorporates an Internet node, with access control, for depositing a minimal set of XML-based graphics files for presentation in an identical map format. Side-by-side viewing and televideo conferencing will permit rapid evaluation, data elaboration and recalculation (if necessary) and should produce strong consensus among decision makers. Successful completion affords easy utilisation by national/international organisations and non-nuclear states at risk of trans-boundary incursion.

Third-party inspection as an alternative to command and control regulation.

This article makes the case for relying on decentralized market-based incentive mechanisms to supplement performance-based regulations for promoting industrial safety. In particular, we examine how third-party inspections, coupled with insurance protection, can encourage firms to reduce their risks from accidents and disasters. Our proposal is thus an example of a management-based regulatory strategy where the locus of decision making is shifted from the regulator to firms, which are now required to do their own planning as to how they will meet a set of standards or regulations. The third-party inspections we have in mind would take the form of a voluntary contractual relationship between the firm and the party auditing the facility in place of relying solely on the regulatory agency as enforcer. In undertaking the inspection, the third party can simply play the role of informing the firm that it is in violation of a regulation or, going one step further, it can assist the firm in developing a program for reducing its risks to comply with a particular standard or regulation. The passage of Section 112(r) of the Clean Air Act Amendments (CAAA) of 1990 offers an opportunity to implement such a program. This legislation created two new federal regulatory programs aimed at preventing releases of hazardous chemicals: the Occupational Health and Safety Administration (OSHA) Process Safety Management (PSM) standard and the U.S Environmental Protection Agency (EPA) Risk Management Program. The OSHA program was enacted in 1992 and requires facilities containing large quantities of highly hazardous chemicals to implement accident prevention and emergency response measures to protect workers. The EPA Risk Management Program regulation, published in 1996, borrowed the same accident prevention concepts and language from PSM but went beyond the OSHA program. It also required facilities to perform a hazard assessment, estimate consequences from accidents, and submit a summary report, called the Risk Management Plan (RMP), to EPA by June 21, 1999. The challenge is how to encourage compliance with these regulations so that firms will be operating in a safer manner. The article proceeds as follow. In the next section we make the case for well-enforced RMPs and then show in Section 3 why firms may not voluntarily comply with this regulation. Section 4 shows analytically that third-party inspections coupled with insurance provide economic incentives for many firms to undertake RMPs voluntarily and encourages the remaining recalcitrant firms to comply with the regulation. Section 5 illustrates implementation challenges in utilizing third-party inspections while at the same time pointing to their success in a variety of different contexts. The concluding section discusses a set of open issues and questions, the need for future studies, and what analysts and practitioners can learn from this work.

Emergency preparedness in Germany: recent progress in on-site accident management and off-site emergency response / Emergency preparedness in Germany: recent progress in on-site accident management and off-site emergency response

In Germany, for nuclear power plants a variety of measures has been developed plant internally to prevent core damage and to mitigate its consequences as well as for off-site disaster control. As the most recent achievement in this field the implementation of passive autocatalytic recombiners has been initiated and is carried out now. This measure is counteracting potential threats of hydrogen explosions to containment, building and component integrity; hydrogen is formed during core melt mainly by Zirconium-water reaction. As a further on-site activity the required measures for accident management training are harmonized by the development of exercise manuals. A first volume of this manual has been completed. It is devoted to exercises using conventional event sheets. The second phase is underway forcing the application of full-scope simulators to exercises. A significant activity presently carried out is the implementation of a crisis centre of the Federal Government.