Academic literature on the topic 'Explosions – Safety measures'

On April 20, 2010, an explosion rocked the Deepwater Horizon in the Gulf of Mexico resulting in the deaths of 11 workers. Tens of thousands of documents were released during the investigation for the root cause of the explosion."What emerges is stark and singular fact: crew members died and suffered terrible injuries because every one of the Horizon's defenses failed on April 20. Some were deployed but did not work. Some were activated too late, after they had almost certainly been damaged by fire or explosions. Some were never deployed at all.(Barstow et al. 2011)". Parallels with the aluminium industry standout when comparing the Deepwater Horizon disaster (e.g. violent explosions, damaged equipment, worker deaths and worker injuries). The list of aluminium industry catastrophes is not short: Binzhou Weiqiao Aluminum, Reynolds Alabama, Alcan France, etc. Aluminium plants, just as deepwater oil rigs, value training and safety measures to prevent accidents from occurring. But, on April 20, 2010 every safety measure employed failed, could the safety measures employed in a casthouse to prevent a molten metal steam explosion fail too?

On 17 April 2013, the West Fertilizer Company’s ammonium nitrate storage building exploded, killing 15 persons and injuring over 200. Numerous Federal and State agencies regulated the facility. But none of the agencies demonstrated a viable understanding of what is liable to cause accidental ammonium nitrate explosions, nor what is needed to prevent these. Specifically, none of them recognized the fact that ammonium nitrate fertilizer explosion accidents, when they occur, are inevitably the consequence of an uncontrolled fire and that such fires can be precluded by well-known fire safety measures. In fact, existing regulations have generally focused on everything but features needed to make such storage facilities incapable of sustaining an uncontrolled fire. Ammonium nitrate manufacturers, however, did have technical knowledge concerning safety and were aware of the ineffectiveness of governmental regulations. Espousing proper Product Stewardship principles by the manufacturers would have precluded selling dangerous chemicals to buyers who cannot safely store them.

In the past five years, there have been numerous cases of Li-ion battery fires and explosions, resulting in property damage and bodily injuries. This paper discusses the thermal runaway mechanism and presents various thermal runaway mitigation approaches, including separators, flame retardants, and safety vents. The paper then overviews measures for extinguishing fires, and concludes with a set of recommendations for future research and development.

Existing measures for the suppression of dust and gas emissions during mass explosions at the quarry of a mining and processing plant were investigated. Measures have been developed to reduce dust and gas emissions, taking into account the analysis of existing measures to suppress dust and gas emissions from mass explosions in the open pit of the mining and processing plant of Lebedinsky GOK. The studies of surface active substances on the wettability of dust particles. In order to improve working conditions, it was proposed to reduce dust and gas emissions by suppressing them at the source of education, using the method of wetting and sticking of dust particles. The proposed engineering - technical solution can be used to reduce dust and gas emissions during massive explosions in the quarries of various mining and processing enterprises. The developed method is proposed to be used to ensure environmental safety and improve working conditions in industries with high dustiness by increasing the efficiency of dust collection.

Ранее нами был рассмотрен вопрос о целесообразности более четкой дифференциации процессов горения горючих газо-, паро- и пылевоздушных смесей по показателям горения и критериям, характеризующим последствия аварий, сопровождающихся пожарами и взрывами, также было введено понятие «повышенная дефлаграция» («хлопк»). Такой подход может способствовать устранению коллизий в вопросах определения последствий аварий на объектах защиты, а также исключению различных толкований применимости как для промышленных объектов, так и для жилых зданий мероприятий по обеспечению их пожаровзрывобезопасности. В настоящей работе поставлена обратная задача: исследование закономерностей локализации роста давления при взрыве до критически приемлемых значений, представление средств и способов достижения минимизации последствий аварий и взрывов в зданиях и помещениях. In previously published work there was considered the question of reasonability of differentiation of the combustion processes of combustible mixtures according to combustion parameters and criteria characterizing the accident consequences of involving fires and explosions. The concept of enhanced deflagration (clap) was introduced. Such approach can help to eliminate conflicts in determining the accident consequences at objects of protection, as well as to exclude different interpretations of the applicability of fire and explosion safety measures for both industrial facilities and residential buildings. The task of this paper is to study the regularities of localization of pressure growth during an explosion to critically acceptable values, as well as to present the means and methods for achieving minimization of the accident consequences and explosions in buildings and premises. The flame spreads unevenly with acceleration or deceleration depending on the composition of the fuel mixture, gas dynamic conditions of combustion propagation and other factors. The combustion process intensification in closed volumes is caused by turbulization of the flame due to the influence of gas-dynamic disturbances of various nature on the flame front and is characterized by the coefficient of intensification or turbulization. Safety structures designed to prevent the propagation of explosive wave in a room are the following: glazing; easy-to-throw lightweight wall panels; lightweight coatings. The glazing is the most widely used as easy-to-throw structures both in housing and in industrial premises. The most practical and quite effective is the use of safety structures in the form of glazed window openings with design characteristics that reduce the excess pressure of the shock wave. These measures are not sufficient for industrial facilities. Such measures should include the following: space-planning and design solutions aimed at limiting the spread of fires and the consequences of explosions (for example, limiting the possibility of fire spread (explosion) to neighboring rooms and stairwells by installing vestibule locks); using equipment that prevents the spread of flames and combustion products along production lines; application of systems for combustion and explosion localization in equipment using high-speed devices, fire-prevention and check valves, fire barriers, means of supplying inert gases to it and to product pipelines, phlegmatizing additives or other technical means that prevent the formation of fire-explosive mixtures and their explosion in the presence of an initiation source; protection of equipment and industrial premises from destruction in explosion using explosion dischargers and easy-to-throw structures; use of equipment designed for explosion pressure.

Purpose. Improving the environmental safety of blasting operations in quarries for the extraction of non-metallic and construction materials based on their rational explosive crushing, aimed at reducing the effect of overgrinding, accompanied by the formation of fine fractions of materials and significant dust emissions. The research methodology provided a theoretical analysis of the destruction processes of a rock massif by well charges of explosives on the basis of calculations of shock adiabats of an explosive wave in rocks at different speeds of detonation of explosives. Experimental verification of the identified patterns was performed by assessing the quality of blasting by the particle size distribution of the rock in the collapse. Research results. The scientific and practical task of ensuring rational explosive crushing of materials in quarries with the use of elongated borehole charges has been solved. Mechanisms for the destruction of rock massifs and the peculiarities of the distribution of destruction zones by dispersed composition have been established, which contributes to the reduction of dust emissions into the atmosphere to an acceptable level of environmental safety of blasting operations in quarries. Comparative estimates of the shock load during the explosion of the explosive charge for the main rocks at different levels of the rate of detonation of charges are given. The dependence of the volume of overgrinding rock in the zone of its adjacency to the charge on the detonation velocity of explosives has been established. An experimental verification of the identified patterns in the current quarry by assessing the quality of blasting by the particle size distribution of rock mass in its collapse after experimental explosions with different parameters is done. Scientific novelty. The multiphase process of rock destruction by explosion was investigated by the calculated determination of the parameters of the shock adiabats of the blast wave in different rocks and at different detonation velocities of explosives. It is shown that during the destruction of a rock mass by the explosion of an elongated borehole charge of explosives, several specific zones of destruction are formed, the characteristics of which differ in particle size distribution. The area of controlled crushing is highlighted, where the intensity of rock destruction can be changed by adjusting the parameters of the explosive load and the area of little or almost unregulated crushing. The possibility of managing the process of dust formation and, accordingly, the level of environmental safety of blasting works in quarries for the extraction of non-metallic and construction materials is substantiated. Practical meaning. The identified patterns and provisions to reduce the effect of mineral overgrinding were used in the development of measures to improve the environmental safety of blasting in the quarry, which, in particular, provided an increase in well spacing in the range up to 3.0-3.4 m and reduce specific energy consumption from 1.27 g/cm3 to 0.97 g/cm3.

Fire and explosion accidents occur frequently in tankers because they transport large quantities of dangerous cargo. To prevent fire and explosion accidents, it is necessary to analyze factors that cause accidents and their effects. In this study, factors that cause fire and explosion accidents were classified using the 4M disaster analysis method, and each factor’s effect on the accident was analyzed using fault tree analysis (FTA). First, the unsafe tank atmosphere environment was identified as a primary cause of fire and explosion accidents in tankers, and the underlying causes of these accidents were investigated. The probability of underlying causes leading to primary causes was derived using an expert survey. The results showed that management and media factors had a greater impact on the unsafe tank atmosphere environment than human factors. To prevent fire and explosion accidents, it is necessary to ensure sufficient working and resting times for seafarers and compliance with procedures and work guidelines. A generalization of the results of present and future studies will enable the identification of the cause and preventive measures for fire and explosion accidents in tankers. Furthermore, this will reduce accidents in tankers and contribute to future safety management measures of ships and companies.

AbstractThis article shows incidents associated with the use of gas as an energy carrier. It presents selected incidents which have occurred in Poland and around the world in recent decades. Based on this, consequences of gas and air mixture explosions were analysed as well. The article presents the main causes of gas incidents which have taken place, as per instances which are similar worldwide. Incidents associated with the use of gas are not frequent, but at the same time very tragic as they often lead to illness or even death. In Poland, in the last twenty years, construction area disasters caused by gas explosions account for only 5% of all which have occurred, but the number of fatalities resulting from these cases is approximately 14%. The number of individuals injured reached 39% of all construction disaster victims. Considering all these facts, it is necessary to undertake wide preventive measures in order to increase safety in the use of gaseous fuels.

Background: To date, information on laser treatment of accidental tattoos is limited. Objectives: This study analyzes the efficacy and safety of quality-switched ruby, quality-switched Nd:YAG and picosecond lasers in the treatment of accidental hyperpigmentation in a larger patient cohort. To date, there is limited information on laser therapy of accidental hyperpigmentation. Methods: We conducted a retrospective systematic single-center analysis on 70 patients, which presented with accidental hyperpigmentation at the Dermatology Department of the University Hospital of Zurich between 2008 and 2017. Patients with accidental tattoos due to road injuries, explosives or other traumas and iatrogenic measures were included. We analyzed the data including laser parameters such as wavelength, energy density, spot size and intervals between the sessions. Also, the number of sessions performed and the overall success were registered. Results: We treated 38 patients by quality-switched nano- and/or picosecond laser therapy and completed the treatment in 28 cases within a mean number of 3–5 laser sessions. No complications occurred. Conclusion: We demonstrate the validity and safety of quality-switched and picosecond lasers in the treatment of accidental hyperpigmentation. Using a combination of different wavelengths and pulse lengths on the same lesion and gradually increasing the fluence in the course of the laser treatment is recommendable to increase efficacy. We observed a tendency towards faster elimination of facial accidental tattoos and/or originating from road injuries compared to tattoos located on the extremities and those caused by explosions, piercings or iatrogenic measures or consisting of metal pigment particles.

Policing is one of the riskiest and dangerous professions by its nature. Police officers face a range of risks at work: homicide, assaults, attacks, communicable diseases, car crashes or explosions. The risks vary according to the task being undertaken such as arresting offenders, attending street disturbances or performing traffic duties. These risks, having the characteristics of occupational accident in a way, have institutional losses like compensation, loss of manpower and reputation besides individual results like injury, death, mutilation, and posttraumatic stress disorder, exposure to psychological disorders or decrease in quality of life. Opinions and suggestions of 1066 employees currently working at different ranks and units in Turkish National Police in regards with reducing the risks of occupational accidents and safety risks were studied in this research. Suggestions of the participants were reviewed under total nine headings (themes) consisting of training, physical fitness and health, security measures, institutional policies and procedures, managerial policies, working conditions, equipment, uniforms, and patrol cars.

Les Etudes Probabilistes de Sûreté (EPS) de niveau 2 en centrale nucléaire visent à identifier les séquences d’événements pouvant correspondre à la propagation d’un accident d’un endommagement du cœur jusqu’à une perte potentielle de l’intégrité de l’enceinte, et à estimer la fréquence d’apparition des différents scénarios possibles.

Ces accidents sévères dépendent non seulement de défaillances matérielles ou d’erreurs humaines, mais également de l’occurrence de phénomènes physiques, tels que des explosions vapeur ou hydrogène. La prise en compte de tels phénomènes dans le cadre booléen des arbres d’événements s’avère difficile, et les méthodologies dynamiques de réalisation des EPS sont censées fournir une manière plus cohérente d’intégrer l’évolution du processus physique dans les changements de configuration discrète de la centrale au long d’un transitoire accidentel.

Cette thèse décrit l’application d’une des plus récentes approches dynamiques des EPS – la Théorie de la Dynamique Probabiliste basée sur les Stimuli (SDTPD) – à différents modèles de déflagration d'hydrogène ainsi que les développements qui ont permis cette applications et les diverses améliorations et techniques qui ont été mises en oeuvre.

Level-2 Probabilistic Safety Analyses (PSA) of nuclear power plants aims to identify the possible sequences of events corresponding to an accident propagation from a core damage to a potential loss of integrity of the containment, and to assess the frequency of occurrence of the different scenarios.

These so-called severe accidents depend not only on hardware failures and human errors, but also on the occurrence of physical phenomena such as e.g. steam or hydrogen explosions. Handling these phenomena in the classical Boolean framework of event trees is not convenient, and dynamic methodologies to perform PSA studies are expected to provide a more consistent way of integrating the physical process evolution with the discrete changes of plant configuration along an accidental transient.

This PhD Thesis presents the application of one of the most recently proposed dynamic PSA methodologies, i.e. the Stimulus-Driven Theory of Probabilistic Dynamics (SDTPD), to several models of hydrogen explosion in the containment of a plant, as well as the developed methods and improvements.

Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

The primary objectives of the described research were to examine the underlying physical phenomena occurring during flame/obstacles interactions in various chambers of low L/D ratio and to develop a new empirical equation for explosion venting. A literature review suggested that the propagating flame/obstacle interactions in enclosures with large L/D ratio (> 2) result in flame acceleration and subsequent pressure build-up during a gas explosion. However, the interactions in practical situations with small L/D < 2 were not extensively studied. In this thesis the first investigation involved the flame interaction with different single and multiple obstacles in a 1/20th model of real enclosure. Results provided the basis for flame propagation, local flame displacement speed probability density functions (pdfs), mean flame velocity and explosion pressure. The second investigation of the study involved the flame interaction with multiple bars within chambers of different L/D ratios. The results provided mean flame velocities on each stage, as a function of nondimensional time, and pressure developments as a function of L/D ratio. The final investigation is associated with gas explosion venting. The predictive ability between existing models on explosion venting and experimental results obtained in this thesis were undertaken and found to be deficient. Consequently a new empirical model for predicting explosion venting was developed. The new model was validated with experimental data published in literature.

Over the years computer systems have evolved from centralized monolithic computing devices supporting static applications, into client-server environments that allow complex forms of distributed computing. Throughout this evolution limited forms of code mobility have existed. The explosion in the use of the World Wide Web coupled with the rapid evolution of the platform independent programming languages has promoted the use of mobile code and at the same time raised some important security issues. This chapter introduces mobile code technology and discusses the related security issues. The first part of the chapter deals with the need for mobile codes and the various methods of categorizing them. One method of categorising the mobile code is based on code mobility. Different forms of code mobility like code on demand, remote evaluation and mobile agents are explained in detail. The other method is based on the type of code distributed. Various types of codes like Source Code, Intermediate Code, Platform-dependent Binary Code, Just-in-Time Compilation are explained. Mobile agents, as autonomously migrating software entities, present great challenges to the design and implementation of security mechanisms. The second part of this chapter deals with the security issues. These issues are broadly divided into code related issues and host related issues. Techniques like Sandboxing, Code signing and Proof carrying code are widely applied to protect the hosts. Execution tracing, Mobile cryptography, Obfuscated code, Co-Operating Agents are used to protect the code from harmful agents. The security mechanisms like language support for safety, OS level security and safety policies are discussed in the last section. In order to make the mobile code approach practical, it is essential to understand mobile code technology. Advanced and innovative solutions are to be developed to restrict the operations that mobile code can perform but without unduly restricting its functionality. It is also necessary to develop formal, extremely easy to use safety measures.

Over the years, computer systems have evolved from centralized monolithic computing devices supporting static applications, into client-server environments that allow complex forms of distributed computing. Throughout this evolution, limited forms of code mobility have existed. The explosion in the use of the World Wide Web, coupled with the rapid evolution of the platform- independent programming languages, has promoted the use of mobile code and, at the same time, raised some important security issues. This chapter introduces mobile code technology and discusses the related security issues. The first part of the chapter deals with the need for mobile codes and the various methods of categorising them. One method of categorising the mobile code is based on code mobility. Different forms of code mobility, like code on demand, remote evaluation, and mobile agents, are explained in detail. The other method is based on the type of code distributed. Various types of codes, like source code, intermediate code, platform-dependent binary code, and just-in-time compilation, are explained. Mobile agents, as autonomously migrating software entities, present great challenges to the design and implementation of security mechanisms. The second part of this chapter deals with the security issues. These issues are broadly divided into code-related issues and host-related issues. Techniques, like sandboxing, code signing, and proof-carrying code, are widely applied to protect the hosts. Execution tracing, mobile cryptography, obfuscated code, and cooperating agents are used to protect the code from harmful agents. The security mechanisms, like language support for safety, OS level security, and safety policies, are discussed in the last section. In order to make the mobile code approach practical, it is essential to understand mobile code technology. Advanced and innovative solutions are to be developed to restrict the operations that mobile code can perform, but without unduly restricting its functionality. It is also necessary to develop formal, extremely easy-to-use safety measures.

Over the years, computer systems have evolved from centralized monolithic computing devices supporting static applications, into client-server environments that allow complex forms of distributed computing. Throughout this evolution, limited forms of code mobility have existed. The explosion in the use of the World Wide Web, coupled with the rapid evolution of the platform- independent programming languages, has promoted the use of mobile code and, at the same time, raised some important security issues. This chapter introduces mobile code technology and discusses the related security issues. The first part of the chapter deals with the need for mobile codes and the various methods of categorising them. One method of categorising the mobile code is based on code mobility. Different forms of code mobility, like code on demand, remote evaluation, and mobile agents, are explained in detail. The other method is based on the type of code distributed. Various types of codes, like source code, intermediate code, platform-dependent binary code, and just-in-time compilation, are explained. Mobile agents, as autonomously migrating software entities, present great challenges to the design and implementation of security mechanisms. The second part of this chapter deals with the security issues. These issues are broadly divided into code-related issues and host-related issues. Techniques, like sandboxing, code signing, and proof-carrying code, are widely applied to protect the hosts. Execution tracing, mobile cryptography, obfuscated code, and cooperating agents are used to protect the code from harmful agents. The security mechanisms, like language support for safety, OS level security, and safety policies, are discussed in the last section. In order to make the mobile code approach practical, it is essential to understand mobile code technology. Advanced and innovative solutions are to be developed to restrict the operations that mobile code can perform, but without unduly restricting its functionality. It is also necessary to develop formal, extremely easy-to-use safety measures.

Over the years, computer systems have evolved from centralized monolithic computing devices supporting static applications, into client-server environments that allow complex forms of distributed computing. Throughout this evolution, limited forms of code mobility have existed. The explosion in the use of the World Wide Web, coupled with the rapid evolution of the platform-independent programming languages, has promoted the use of mobile code and, at the same time, raised some important security issues. This chapter introduces mobile code technology and discusses the related security issues. The first part of the chapter deals with the need for mobile codes and the various methods of categorising them. One method of categorising the mobile code is based on code mobility. Different forms of code mobility, like code on demand, remote evaluation, and mobile agents, are explained in detail. The other method is based on the type of code distributed. Various types of codes, like source code, intermediate code, platform-dependent binary code, and just-in-time compilation, are explained. Mobile agents, as autonomously migrating software entities, present great challenges to the design and implementation of security mechanisms. The second part of this chapter deals with the security issues. These issues are broadly divided into code-related issues and host-related issues. Techniques, like sandboxing, code signing, and proof-carrying code, are widely applied to protect the hosts. Execution tracing, mobile cryptography, obfuscated code, and cooperating agents are used to protect the code from harmful agents. The security mechanisms, like language support for safety, OS level security, and safety policies, are discussed in the last section. In order to make the mobile code approach practical, it is essential to understand mobile code technology. Advanced and innovative solutions are to be developed to restrict the operations that mobile code can perform, but without unduly restricting its functionality. It is also necessary to develop formal, extremely easy-to-use safety measures.

Hydrogen use as an energy carrier and wide distribution of hydrogen in high technologies over the world, especially taking into account the explosivity of hydrogen being mixed with ambient air, leads to strong demand of safety measures and safety distances evaluation. Unconfined explosion of hydrogen-air mixture or high-pressure hydrogen tank rupture are the worst accident scenarios to be well predicted and mitigated or avoided, if possible. Thus, the analysis of existing data and the new experimental data on hydrogen-air and high-pressure hydrogen explosions are required to develop the safety recommendations and user guidelines for industry and technologies.

Explosions produced in urban areas by the detonation of explosives are low-probability but high-impact events. When they occur in the immediate vicinity of buildings, the explosions can pose a high risk to the structural integrity (local/global failures) and to the occupants (risk of injury, death). Therefore, the design and the construction of the buildings should contain preventive measures to increase the robustness of the structures. The paper presents the results of recent research carried out on the safety of building structures under extreme actions. Blast tests performed on two identical 3D specimen extracted from a typical moment resisting steel frame structure, allow to calibrate the numerical models of a full scale building structural frame system and evaluate the consequences of close-in detonations on the structural elements. The data of the experimental testing, combined with the numerical modelling, allow to investigate different factors, such as dynamic factors that affect the local failure mechanism and the residual capacity of steel columns under different blast scenarios.

U. S. commercial reactor plants are installing spent fuel storage facilities formally called Independent Spent Fuel Storage Installations (ISFSI) to provide needed storage space for spent nuclear fuel assemblies. Although this might be a primary objective for the utility that owns the plant, the U.S. Nuclear Regulatory Commission (U.S. NRC) has other priorities as addressed by ISFSI regulations in Title 10 of the Code of Federal Regulations, Part 72. These regulations establish a number of criteria that ensure that above all, the storage of spent nuclear fuel does not adversely affect the health and safety of the public or the environment. There are 3 primary ISFSI design activities that ensure the health and safety of the public and protection of the environment: site selection, storage system selection, and storage facility design. The regulatory requirements that address ISFSI site selection are found in 10 CFR 72, Subpart E, “Siting Evaluation Factors.” This section requires that potential ISFSI sites be assessed for impacts such as site characteristics that may affect safety or the environment, external natural and man-induced events, radiological and other environmental conditions, floodplains and natural phenomena, man-made facilities and activities that could endanger the ISFSI, and construction, operation, and decommission activities. All of these potential impacts must be carefully evaluated. First, the ISFSI capacity requirements should be determined. Potential sites should then be evaluated for siting impacts to ensure the site has adequate space, it can be licensed, it will minimize radiological doses to the general public and on-site workers, and construction, operation, and decommissioning won’t have a major effect on the environment or nearby population. The regulatory requirements that address storage system selection are found in 10 CFR 72, Subpart F, “General Design Criteria.” This section requires that the storage system be designed to withstand environmental conditions, natural phenomena, fires and explosions and that it includes confinement barriers, retrievability measures, and criticality safety. In order to be licensed by the U. S. NRC, all spent fuel storage systems must be evaluated to show how they meet these requirements. U.S. NRC approval of the system ensures that the requirements have been met and therefore ensure the health and safety of the public and environment are protected. The regulatory requirements that address the ISFSI design are also found in 10 CFR 72, Subpart F as well as 10 CFR 72, Subpart H, “Physical Protection.” Like the storage systems, the ISFSI site must be designed to withstand environmental conditions, natural phenomena, fires, and explosions. But the design must also include security provisions. Security features protect the spent fuel from attack or sabotage and therefore protect the health and safety of the public and the environment. The primary potential impact of spent fuel storage is radiation dose. The key regulatory requirement that addresses radiation dose is found in 10 CFR 72.104. This section requires that the dose to any individual member of the public not exceed 0.25 mSv (25 mrem) to the whole body, 0.75 mSv (75 mrem) to the thyroid, and 0.25 mSv (25 mrem) to any other organ, from exposure to direct radiation from the ISFSI, radioactive liquid or gaseous effluents, and radiation from other nearby nuclear facilities. Design features of the storage system and ISFSI include shielding by the cask enclosure, distance, berms as required, etc. to attenuate direct radiation, and confinement provisions to prevent radiological effluent leakage. The ISFSI must be located such that the cumulative doses from the ISFSI and reactor plant do not exceed regulatory requirements. Thus it can be seen that ISFSI site selection, storage system selection, and storage facility design all work together to ensure the health and safety of the public and environment are protected. Comments regarding the contents of this paper may be submitted to the author, Donald W. Lewis, Shaw Environmental & Infrastructure, 9201 E. Dry Creek Road, Centennial, Colorado, 80112, U.S.A.

Abstract With the rapid development of the national economy, the demand for oil is increasing. In order to meet the increasing energy demand, China has established a number of oil depot in recent years, whose largest capacity reaching up to tens of millions of cubic meters. Due to the flammable and explosive nature of the stored medium, the risk of fire in the oil depot area has increased dramatically as the tank capacity of the storage tank area has increased. The intensification of the oil depot and the development of large-scale oil storage tanks have brought convenience to the national oil depot, but also brought many catastrophic consequences. In recent years, there have been many fires and explosions in the oil depot, causing major casualties and property losses, which seriously endangered the ecological environment and public safety. Based on the constructed oil depot fire risk index system, the fuzzy C-means algorithm (FCM) and fuzzy maximum support tree clustering algorithm is introduced. Through the two fuzzy clustering mathematical models, key factors in the established index system are identified. Firstly, the expert scoring method is used to evaluate the indicators in the oil depot fire risk index system, and the importance degree evaluation matrix of oil depot fire risk factors is constructed through the fuzzy analysis of expert comments. Then, the fuzzy C-means algorithm (FCM) and the fuzzy clustering tree algorithm are used to cluster the various risk indicators, and the key factors of the oil depot fire risk are identified. Through the comparative analysis and cross-validation of the results of the two fuzzy clustering methods, the accuracy of the recognition results is ensured. Finally, using an oil depot as a case study, it is found that passive fire prevention capability and emergency rescue capability are key factors that need to be paid attention to in the oil depot fire risk index. The fuzzy clustering algorithm used in this paper can digitize the subjective comments of experts, thus reducing the influence of human subjective factors. In addition, by using two fuzzy clustering algorithms to analyze and verify the key factors of the oil depot fire risk, the reliability of the clustering results is guaranteed. The identification of key factors can enable managers to predict high-risk factors in advance in the fire risk prevention and control process of the oil depot, so as to adopt corresponding preventive measures to minimize the fire risk in the oil depot, and ensure the safety of the operation of the oil depot.

Combined Heat and Power and Combined Cycle Gas Turbine plants have become larger and more popular in recent years for local power and heat generation, and for main stream power generation. Many are based on gas turbines within acoustic enclosures. Complex fuel supply pipework to the turbines at high pressure gives rise to an explosion hazard within such enclosures in the event of foreseeable small leaks if appropriate ventilation is not provided. Health and Safety Executive investigations have exposed poor ventilation in some cases to the extent that explosion relief or significantly improved ventilation has been required. The paper describes the investigations, with reference to incident data, ignition probability, current relevant standards, and ventilation performance modelling by computational fluid dynamics. Suggested criteria for the evaluation of existing and new plant, and risk reduction measures, are described.

Since Westinghouse Savannah River Company (WSRC) of America first applied PUREX process in 1954, PUREX process is always the top priority in nuclear fuel reprocessing plant. And this process is based on liquid to liquid extraction with TBP as the extractant. TBP is irreplaceable in the development of PUREX process in nuclear fuel reprocessing, its advantages are well recognized. However TBP does have some disadvantages such as formation of red oil, which will appear in the system of high nitric acid concentration and heavy metal nitrate, once the red oil forms, it can lead a exothermic runaway decomposition in reasonable conditions, such as exceeding a certain temperature (typically 130°C) or high acid concentration. If gas products and energy released from the decomposition reaction could not be exported in time, it will lead to vessel overpressure and caused violent explosion accidents. By now, it has happened 6 times so-called red oil explosion accidents worldwide, resulting in different degrees of equipment and construction damage and environmental contamination. From 1953 to now, research related to red oil has never stopped. WSRC, Hanford Company, Oak Ridge National Laboratory and Los Alamos National Laboratory of America have conducted many studies, as well as some research institutions from Russia, UK, France and India. Defense Nuclear Facilities Safety Board of America issued a technical report in 2003, preventive measures for red oil explosion were established in this report, and these measures provided good practice experience and reference for other countries, and the temperature condition (⩽130°C)and nitric acid concentration (⩽10M)for preventing red oil explosion are employed in some countries which has built the reprocessing plant. Nevertheless, research conclusions and knowledge of red oil vary from country to country. Especially, Kumar and Smitha etc. conducted several experiments in adiabatic condition in recent years, and investigation on stability of TBP - nitric system was made, the results indicated that the red oil runway reaction will happen even in lower temperature and lower nitric acid concentration in contrast with the reported value, and they thought it would need a further study to assess the validity of present preventive measures, and to rebuild the safety limits for preventing red oil explosion in the operation of nuclear fuel reprocessing plants. In this paper, related research results of red oil explosion accidents were combed, and the characters of study work of different periods were summarized, and definition, formation conditions of red oil, pathway of runaway reaction, control and preventive measures for preventing red oil explosion of different countries were analyzed and compared, as well as the new viewpoints of recent literatures. And some research ideas for future investigation based on present work were also proposed.

Abstract Lithium-ion batteries are a proven energy storage device which continue to gain market share across a wide range of applications. However, the safety of these devices is still a major factor in many applications. In failures which result in thermal runaway, a series of chemical reactions are initiated which produce a large quantity of gas and heat. The pressure and temperature inside the battery rise sharply and may cause fire or explosion. The lithium-ion battery vent cap is a key safety device used in 18650 format cells to prevent an energetic failure of the metal casing. In this paper, the cap structure and venting parameters of three cap designs are analyzed. The venting parameters investigated were the open flow area and discharge coefficient. Open flow area through different components of the cap assembly were measured using 3D x-ray scans. A new experimental apparatus was used to measure mass flowrate and pressure ratio across the battery cap, which allowed calculation of discharge coefficient. Results indicate that discharge coefficients follow the same trend as a sharp-edged orifice, albeit at a reduced magnitude due to the more tortuous flow path. A semi-empirical model is proposed to simulate mass flow through the battery cap.

In order to ensure the safety of an offshore structure it is important to identify and maintain the barriers preventing hazardous events. Also, when monitoring the safety, the monitoring should be regarding how well these barriers are functioning, and utilise these to reassess the safety of the structure over time. The purpose of this paper is to apply a well-known method in risk assessment, Haddon’s energy and barrier model, to a new area; structural safety. The purposes of this exercise are to look at the structural safety from a risk assessment point of view, and to use this to identify and give an overview of the existing barriers. Furthermore, the purposes are to evaluate the efficiency and redundancy of these barriers, and to use this to evaluate the safety of offshore structures. This paper will analyse the safety of a fixed offshore structure through a qualitative approach. A possible event chart for a fixed offshore installation during operation in storms is established and analysed. Some of the root causes for potential structural failure are identified. These root-causes are kept on a general level, but considered in more detail than often seen in risk analysis. Hazards that are normally included in risk analysis, like boat collisions, fire, explosions, and dropped objects are not evaluated. Hazards that are evaluated are structural failure due to wave loading, fatigue damage, aging, and gross errors in design, fabrication, installation and operation. In order to identify the barriers (hazard reduction strategies, physical barriers and vulnerable target protection strategies), the different failure paths in the event chart are then analysed using Haddon’s ten preventive strategies for reducing damage from hazards. As an example a fixed offshore steel structure is used. A list of proposed barriers that influence the safety of such a fixed offshore installation are presented, and methods to measure these barriers are discussed.

Attention to safety and health are of ever-increasing priority to industrial organizations. Good Safety is demanded by stockholders, employees, and the community while increasing injury costs provide additional motivation for safety and health excellence. Safety has always been a strong corporate value of DuPont and a vital part of its culture. As a result, DuPont has become a benchmark in safety and health performance. Since 1990, DuPont has re-engineered itself to meet global competition and address future vision. In the new re-engineered organizational structures, DuPont has also had to re-engineer its safety management systems. A special Discovery Team was chartered by DuPont senior management to determine the “best practices’ for safety and health being used in DuPont best-performing sites. A summary of the findings is presented, and five of the practices are discussed. Excellence in safety and health management is more important today than ever. Public awareness, federal and state regulations, and enlightened management have resulted in a widespread conviction that all employees have the right to work in an environment that will not adversely affect their safety and health. In DuPont, we believe that excellence in safety and health is necessary to achieve global competitiveness, maintain employee loyalty, and be an accepted member of the communities in which we make, handle, use, and transport products. Safety can also be the “catalyst” to achieving excellence in other important business parameters. The organizational and communication skills developed by management, individuals, and teams in safety can be directly applied to other company initiatives. As we look into the 21st Century, we must also recognize that new organizational structures (flatter with empowered teams) will require new safety management techniques and systems in order to maintain continuous improvement in safety performance. Injury costs, which have risen dramatically in the past twenty years, provide another incentive for safety and health excellence. Shown in the Figure 1, injury costs have increased even after correcting for inflation. Many companies have found these costs to be an “invisible drain” on earnings and profitability. In some organizations, significant initiatives have been launched to better manage the workers’ compensation systems. We have found that the ultimate solution is to prevent injuries and incidents before they occur. A globally-respected company, DuPont is regarded as a well-managed, extremely ethical firm that is the benchmark in industrial safety performance. Like many other companies, DuPont has re-engineered itself and downsized its operations since 1985. Through these changes, we have maintained dedication to our principles and developed new techniques to manage in these organizational environments. As a diversified company, our operations involve chemical process facilities, production line operations, field activities, and sales and distribution of materials. Our customer base is almost entirely industrial and yet we still maintain a high level of consumer awareness and positive perception. The DuPont concern for safety dates back to the early 1800s and the first days of the company. In 1802 E.I. DuPont, a Frenchman, began manufacturing quality grade explosives to fill America’s growing need to build roads, clear fields, increase mining output, and protect its recently won independence. Because explosives production is such a hazardous industry, DuPont recognized and accepted the need for an effective safety effort. The building walls of the first powder mill near Wilmington, Delaware, were built three stones thick on three sides. The back remained open to the Brandywine River to direct any explosive forces away from other buildings and employees. To set the safety example, DuPont also built his home and the homes of his managers next to the powder yard. An effective safety program was a necessity. It represented the first defense against instant corporate liquidation. Safety needs more than a well-designed plant, however. In 1811, work rules were posted in the mill to guide employee work habits. Though not nearly as sophisticated as the safety standards of today, they did introduce an important basic concept — that safety must be a line management responsibility. Later, DuPont introduced an employee health program and hired a company doctor. An early step taken in 1912 was the keeping of safety statistics, approximately 60 years before the federal requirement to do so. We had a visible measure of our safety performance and were determined that we were going to improve it. When the nation entered World War I, the DuPont Company supplied 40 percent of the explosives used by the Allied Forces, more than 1.5 billion pounds. To accomplish this task, over 30,000 new employees were hired and trained to build and operate many plants. Among these facilities was the largest smokeless powder plant the world had ever seen. The new plant was producing granulated powder in a record 116 days after ground breaking. The trends on the safety performance chart reflect the problems that a large new work force can pose until the employees fully accept the company’s safety philosophy. The first arrow reflects the World War I scale-up, and the second arrow represents rapid diversification into new businesses during the 1920s. These instances of significant deterioration in safety performance reinforced DuPont’s commitment to reduce the unsafe acts that were causing 96 percent of our injuries. Only 4 percent of injuries result from unsafe conditions or equipment — the remainder result from the unsafe acts of people. This is an important concept if we are to focus our attention on reducing injuries and incidents within the work environment. World War II brought on a similar set of demands. The story was similar to World War I but the numbers were even more astonishing: one billion dollars in capital expenditures, 54 new plants, 75,000 additional employees, and 4.5 billion pounds of explosives produced — 20 percent of the volume used by the Allied Forces. Yet, the performance during the war years showed no significant deviation from the pre-war years. In 1941, the DuPont Company was 10 times safer than all industry and 9 times safer than the Chemical Industry. Management and the line organization were finally working as they should to control the real causes of injuries. Today, DuPont is about 50 times safer than US industrial safety performance averages. Comparing performance to other industries, it is interesting to note that seemingly “hazard-free” industries seem to have extraordinarily high injury rates. This is because, as DuPont has found out, performance is a function of injury prevention and safety management systems, not hazard exposure. Our success in safety results from a sound safety management philosophy. Each of the 125 DuPont facilities is responsible for its own safety program, progress, and performance. However, management at each of these facilities approaches safety from the same fundamental and sound philosophy. This philosophy can be expressed in eleven straightforward principles. The first principle is that all injuries can be prevented. That statement may seem a bit optimistic. In fact, we believe that this is a realistic goal and not just a theoretical objective. Our safety performance proves that the objective is achievable. We have plants with over 2,000 employees that have operated for over 10 years without a lost time injury. As injuries and incidents are investigated, we can always identify actions that could have prevented that incident. If we manage safety in a proactive — rather than reactive — manner, we will eliminate injuries by reducing the acts and conditions that cause them. The second principle is that management, which includes all levels through first-line supervisors, is responsible and accountable for preventing injuries. Only when senior management exerts sustained and consistent leadership in establishing safety goals, demanding accountability for safety performance and providing the necessary resources, can a safety program be effective in an industrial environment. The third principle states that, while recognizing management responsibility, it takes the combined energy of the entire organization to reach sustained, continuous improvement in safety and health performance. Creating an environment in which employees feel ownership for the safety effort and make significant contributions is an essential task for management, and one that needs deliberate and ongoing attention. The fourth principle is a corollary to the first principle that all injuries are preventable. It holds that all operating exposures that may result in injuries or illnesses can be controlled. No matter what the exposure, an effective safeguard can be provided. It is preferable, of course, to eliminate sources of danger, but when this is not reasonable or practical, supervision must specify measures such as special training, safety devices, and protective clothing. Our fifth safety principle states that safety is a condition of employment. Conscientious assumption of safety responsibility is required from all employees from their first day on the job. Each employee must be convinced that he or she has a responsibility for working safely. The sixth safety principle: Employees must be trained to work safely. We have found that an awareness for safety does not come naturally and that people have to be trained to work safely. With effective training programs to teach, motivate, and sustain safety knowledge, all injuries and illnesses can be eliminated. Our seventh principle holds that management must audit performance on the workplace to assess safety program success. Comprehensive inspections of both facilities and programs not only confirm their effectiveness in achieving the desired performance, but also detect specific problems and help to identify weaknesses in the safety effort. The Company’s eighth principle states that all deficiencies must be corrected promptly. Without prompt action, risk of injuries will increase and, even more important, the credibility of management’s safety efforts will suffer. Our ninth principle is a statement that off-the-job safety is an important part of the overall safety effort. We do not expect nor want employees to “turn safety on” as they come to work and “turn it off” when they go home. The company safety culture truly becomes of the individual employee’s way of thinking. The tenth principle recognizes that it’s good business to prevent injuries. Injuries cost money. However, hidden or indirect costs usually exceed the direct cost. Our last principle is the most important. Safety must be integrated as core business and personal value. There are two reasons for this. First, we’ve learned from almost 200 years of experience that 96 percent of safety incidents are directly caused by the action of people, not by faulty equipment or inadequate safety standards. But conversely, it is our people who provide the solutions to our safety problems. They are the one essential ingredient in the recipe for a safe workplace. Intelligent, trained, and motivated employees are any company’s greatest resource. Our success in safety depends upon the men and women in our plants following procedures, participating actively in training, and identifying and alerting each other and management to potential hazards. By demonstrating a real concern for each employee, management helps establish a mutual respect, and the foundation is laid for a solid safety program. This, of course, is also the foundation for good employee relations. An important lesson learned in DuPont is that the majority of injuries are caused by unsafe acts and at-risk behaviors rather than unsafe equipment or conditions. In fact, in several DuPont studies it was estimated that 96 percent of injuries are caused by unsafe acts. This was particularly revealing when considering safety audits — if audits were only focused on conditions, at best we could only prevent four percent of our injuries. By establishing management systems for safety auditing that focus on people, including audit training, techniques, and plans, all incidents are preventable. Of course, employee contribution and involvement in auditing leads to sustainability through stakeholdership in the system. Management safety audits help to make manage the “behavioral balance.” Every job and task performed at a site can do be done at-risk or safely. The essence of a good safety system ensures that safe behavior is the accepted norm amongst employees, and that it is the expected and respected way of doing things. Shifting employees norms contributes mightily to changing culture. The management safety audit provides a way to quantify these norms. DuPont safety performance has continued to improve since we began keeping records in 1911 until about 1990. In the 1990–1994 time frame, performance deteriorated as shown in the chart that follows: This increase in injuries caused great concern to senior DuPont management as well as employees. It occurred while the corporation was undergoing changes in organization. In order to sustain our technological, competitive, and business leadership positions, DuPont began re-engineering itself beginning in about 1990. New streamlined organizational structures and collaborative work processes eliminated many positions and levels of management and supervision. The total employment of the company was reduced about 25 percent during these four years. In our traditional hierarchical organization structures, every level of supervision and management knew exactly what they were expected to do with safety, and all had important roles. As many of these levels were eliminated, new systems needed to be identified for these new organizations. In early 1995, Edgar S. Woolard, DuPont Chairman, chartered a Corporate Discovery Team to look for processes that will put DuPont on a consistent path toward a goal of zero injuries and occupational illnesses. The cross-functional team used a mode of “discovery through learning” from as many DuPont employees and sites around the world. The Discovery Team fostered the rapid sharing and leveraging of “best practices” and innovative approaches being pursued at DuPont’s plants, field sites, laboratories, and office locations. In short, the team examined the company’s current state, described the future state, identified barriers between the two, and recommended key ways to overcome these barriers. After reporting back to executive management in April, 1995, the Discovery Team was realigned to help organizations implement their recommendations. The Discovery Team reconfirmed key values in DuPont — in short, that all injuries, incidents, and occupational illnesses are preventable and that safety is a source of competitive advantage. As such, the steps taken to improve safety performance also improve overall competitiveness. Senior management made this belief clear: “We will strengthen our business by making safety excellence an integral part of all business activities.” One of the key findings of the Discovery Team was the identification of the best practices used within the company, which are listed below: ▪ Felt Leadership – Management Commitment ▪ Business Integration ▪ Responsibility and Accountability ▪ Individual/Team Involvement and Influence ▪ Contractor Safety ▪ Metrics and Measurements ▪ Communications ▪ Rewards and Recognition ▪ Caring Interdependent Culture; Team-Based Work Process and Systems ▪ Performance Standards and Operating Discipline ▪ Training/Capability ▪ Technology ▪ Safety and Health Resources ▪ Management and Team Audits ▪ Deviation Investigation ▪ Risk Management and Emergency Response ▪ Process Safety ▪ Off-the-Job Safety and Health Education Attention to each of these best practices is essential to achieve sustained improvements in safety and health. The Discovery Implementation in conjunction with DuPont Safety and Environmental Management Services has developed a Safety Self-Assessment around these systems. In this presentation, we will discuss a few of these practices and learn what they mean. Paper published with permission.

Key performance indicators (KPIs) are widely used to assess performance against targets, whether these be technical, environmental or financial. Offshore KPIs are used by both duty holders and regulators to assess the reliability of equipment and systems, often they relate to safety systems and the regulator’s interest relates to such systems. The most obvious KPIs include number of fatalities, fatal accident rate, lost time injury frequency and total recordable incident rate, as well as hydrocarbon release incident rates associated with maintaining safety. Many of the “non-headline” KPIs relate to systems that could be critical in the event of an accident and these are of great importance. However KPIs have not yet been developed for the performance of the offshore structural system. Performance standards are a requirement of current UK offshore legislation, although these again are more normally associated with fire and explosion. Since many offshore installations are now in the ageing phase performance measures are increasingly important. This paper described the background to developing KPIs for offshore structures, relating to aspects which are important for both safety and asset integrity. This has been achieved based on a hazard approach, which includes extreme weather, fatigue, corrosion and accidental damage. KPI’s need to be measurable and this aspect has been incorporated in their development. It is proposed that these KPIs will have significant use in providing a basis for measuring structural performance, particularly for ageing installations where a case for life extension needs to be made.