Study of Major Accidents Involving Chemical Reactive Substances: Analysis and Lessons Learned

The objective of this paper is to present the results of the analysis performed on a selection of accidents included in the MARS database. This is a database of past accidents that occurred in Europe maintained by the European Commission, in order to help the Member States to meet the requirements of the Seveso and Seveso II directives. The study is focused on those accidents that involve reactions between chemical substances, whether wanted or unwanted, that generated a hazardous situation by loss of control of such reactions. Runaway reactions are known to be especially dangerous, given that many times they are unexpected, or their possible consequences underestimated, so sometimes chemical industries are not ready to cope with the effects of loss of control of reactive processes. The aim of the analysis is to obtain lessons learned from past accidents in order to prevent similar situations in the future, or to reduce their consequences. Understanding the causes of past accidents, including equipment failures, deviations in the expected course of a reaction, or deficiencies in process operations performed, can help to a better understanding of similar processes. Industries working with potentially dangerous chemicals should consider introducing lessons learned into their safety management systems.     

Learning from Tabasco’s floods by applying MORT

Natural disasters are increasing alarmingly worldwide in recent years. They have killed millions of people, and adversely affected the life of at least one billion people. Given this, natural disasters present a great challenge to society today concerning how they are to be mitigated so as to produce an acceptable risk is a question which has come to the fore in dramatic ways recently. In 2007, the state of Tabasco, Mexico, was flooded and it is believed that al least one million people were left homeless. The paper addresses the following question: what can be learnt from flood disasters? The paper presents some preliminary results of the analysis of the Tabasco’s flooding by applying the Management Oversight Risk Tree (MORT). The MORT technique may be regarded as a structured checklist in the form of a complex ‘fault-tree’ model that is intended to ensure that all aspects of an organization’s management are looked into when assessing the possible causes of an incident. One of the key conclusions of the present analysis is that the approach to decision making in relation ‘flood management’ at the time of the disaster has not been based explicitly on ‘flood risk assessment’. It is hoped that by conducting such analysis lessons can be learnt so that the impact of natural disasters such as the Tabasco’s flooding can be mitigated in the future.     

Causes and lessons of five explosion accidents

This paper describes five disastrous explosion accidents that occurred in recent years that had serious consequences for lives and property. The five explosions were: 1) The explosion at a TNT workshop of a chemical factory, Liaoning province, on February 9, 1991 in which 17 employees died and 107 were injured; 2) The nitro-amine explosive production workshop of a chemical factory in Hubei province on June 27, 1992, which led to the deaths of 22 employees and 13 injuries; 3) An explosion in storage warehouses containing dangerous goods in Shenzhen City on August 5, 1993, where 141 were injured; 4) A explosion of a truck loaded with 1.05 million detonators on October 23, 1994 causing 5 deaths and 95 injuries; and 5) An RDX explosive accident in Hunan province on January 31, 1996 in which 134 people died and 17 were injured. In this paper, the causes of these accidents are described and the lessons to be learned from these accidents are summarized.Great changes and significant achievements have taken place and the national economy has been developing at high speed since China reform and open policy. But as far as safety in production is concerned, catastrophic explosion accidents have occurred in recent times and some of them have been exceptionally serious. The author has participated in the investigation of many explosion accidents, which brought about heavy casualties and great economic losses. The bitter experiences have given us many beneficial lessons written in blood from which we must try to avoid such similar unnecessary accidents. In this paper, the causes of five disastrous explosion accidents are analyzed and lessons learned from these accidents are summarized. Proposals for safety production are also put forward.     

Handheld-Assisted Field Data Collection for Occupational Risk Assessment

A computerized handheld procedure is presented in this paper. It is intended as a database complementary tool, to enhance prospective risk analysis in the field of occupational health. The Pendragon forms software (version 3.2) has been used to implement acquisition procedures on Personal Digital Assistants (PDAs) and to transfer data to a computer in an MS-Access format. The data acquisition strategy proposed relies on the risk assessment method practiced at the Institute of Occupational Health Sciences (IST). It involves the use of a systematic hazard list and semi-quantitative risk assessment scales. A set of 7 modular forms has been developed to cover the basic need of field audits. Despite the minor drawbacks observed, the results obtained so far show that handhelds are adequate to support field risk assessment and follow-up activities. Further improvements must still be made in order to increase the tool effectiveness and field adequacy.     

Assessing the number of fire fatalities in a defined population

IntroductionFire-related fatalities and injuries have become a growing governmental concern in Sweden, and a national vision zero strategy has been adopted stating that nobody should get killed or seriously injured from fires. There is considerable uncertainty, however, regarding the numbers of both deaths and injuries due to fires. Different national sources present different numbers, even on deaths, which obstructs reliable surveillance of the problem over time. We assume the situation is similar in other countries. This study seeks to assess the true number of fire-related deaths in Sweden by combining sources, and to verify the coverage of each individual source. By doing so, we also wish to demonstrate the possibilities of improved surveillance practices.MethodData from three national sources were collected and matched; a special database on fatal fires held by The Swedish Contingencies Agency (nationally responsible for fire prevention), a database on forensic medical examinations held by the National Board of Forensic Medicine, and the cause of death register held by the Swedish National Board of Health and Welfare.ResultsThe results disclose considerable underreporting in the single sources. The national database on fatal fires, serving as the principal source for policymaking on fire-prevention matters, underestimates the true situation by 20%. Its coverage of residential fires appears to be better than other fires.ConclusionsSystematic safety work and informed policy-making presuppose access to correct and reliable numbers. By combining several different sources, as suggested in this study, the national database on fatal fires is now considerably improved and includes regular matching with complementary sources.     

Missing safety measures led to the jet fire and seven deaths at a steel plant in Turin. Dynamics and lessons learned

The Authors of this paper are the technical experts that were entrusted by the Public Prosecutor to conduct the technical inquiry into the accident that occurred in the ThyssenKrupp plant in Torino on December 6, 2007. The paper contains the results of the inquiry under the above mentioned point of view. The dynamics of the accident, the main causes and the consequences have been defined.This was an unusual accident from which important lessons can be learned. On December 6, a modest fire developed in the entry section of a pickling and annealing line in the TK plant in Turin. The eight workers on duty seized the firefighting equipment and started to try to extinguish the fire. The workers had portable fire extinguishers and a fire hydrant, so they had to get close to the fire to fight it. Suddenly, a violent jet fire, caused by the rupture of a hydraulic circuit, occurred. The flame instantaneously struck the eight workers while they were still fighting the fire. Seven workers suffered very serious burns, one died instantaneously while the other six had over the following month. One of the workers, who was partly protected by an operating machine, suffered only minor burns and survived. The paper contains some important lessons that have been learned from the present case, which demonstrate that the fire risk at pickling and annealing lines has generally been underestimated by the steel industry. The fire risk due to hydraulic actuators is also evident and new fire fighting strategies are suggested.     

Professional ethics and corporate social responsibility

Sharing accident information and learning the lessons is an important way of reducing errors in any industry. All human beings make errors at some time and it is necessary that design and operational work must be capable of dealing with human fallibility. It is necessary for a management system in all companies to deal with the sharing of information and the learning of lessons from the information. Companies have been reluctant to share information and engineers reluctant to provide information on accidents for fear of the consequences. This paper deals with the ethics issue of the engineer and the social responsibilities of companies to their employees and the public. It is proposed that the professional bodies should make efforts to ensure companies share accident information so that the risks involved in the industry are reduced for the benefit of all.     

An urban pipeline accident model based on system engineering and game theory

Urban pipeline accidents are caused by complex social-technical factors, in which urban communities and pipeline systems are involved. Such accidents can thus be investigated from the viewpoint of system engineering. System-Theoretic Accident Model and Processes (STAMP) is a systemic method for safety assessment, which has been adopted in many domains. This approach can provide deep insights of accident causes by considering direct and indirect factors. Meanwhile, competition and cooperation between stakeholders in accidents are observed. Therefore, these parties can also be analyzed with the game theory. That is, stakeholders in STAMP can be regarded as players in game. The aim of this paper is to provide a new insight to analyze urban pipeline accidents by considering both STAMP and game theory. In this paper, we proposed an accident model for urban pipelines, with a case study of China-Qingdao pipeline accident occurred in 2013. We concluded that accident reasons can be investigated in-depth and lessons can be learned from analyzing causal factors by using STAMP. Based on results generated from STAMP, we applied the game theory to analyze roles that government and companies act in the China-Qingdao urban pipeline accident. The results show that current punishment and incentive systems are incomplete, lacking of the driving force and constraining force for the stakeholders involved in the accident.     

泡沫灭火剂生物降解性能研究及发展趋势

阐述了泡沫灭火剂生物降解原理、一般过程及作用机制,分析了影响其生物降解性的主要因素,并对包括OECD 301系列标准在内的可用于泡沫灭火剂生物降解测试的方法和标准进行了综述,进而对目前国内外该领域的研究现状进行比较和分析。基于目前泡沫灭火剂生物降解性能的研究较为缺乏,不同种类泡沫灭火剂生物降解性差异较大的现状,提出了基于生物降解性能筛选的泡沫灭火剂优化体系的建立方法,并分析了其未来研究方向。     

基于数据驱动的石化装置静态报警抑制策略研究

由生产状态变化引起的误报警频发,为解决现有针对基于状态报警的抑制方法缺乏完整性与定量分析的问题,提出了新的报警抑制策略。通过分析报警记录等数据库,对引起报警的生产条件进行结构化整定并量化,利用分类筛选与数据过滤找出基于状态的报警,再结合关联性分析和概率判断,建立了基于数据驱动的静态报警抑制策略。使用现场数据的试验证明了该方法的有效性。     

基于扇区单元的航路交通流复杂度研究

空中交通航路交通流复杂度越来越高,威胁整个航路的正常运行,严重时甚至影响航空器的运行安全。为研究和解决扇区航路交通流复杂度较高的问题,了解了造成航路交通流复杂度较高的原因。基于航空器的基本运动学方程,列出了航空器运动过程中27种典型的飞行状态组合。考虑航空器的临近效应、速度差异和汇聚梯度3个影响航路交通流复杂度的主要因素,分别建立了相应的测量模型,从3个方面研究对航路交通流复杂度造成的影响,然后采用加权求和的方式求得三方面综合对航路交通流复杂度的影响程度。以雷达模拟机数据作为仿真验证对象,通过MATLAB软件对建立的模型进行了仿真验证     

Solving the seveso II prediction problem of substance generation during loss of control by Al techniques.

The European Directive 96/82/EC forces industries to know exactly what substances may be generated during loss of control of an industrial chemical process. The study must be as accurate as possible, as the design of the safety measures that will be ready in case a real loss of control occurs depends on these results.Chemical reactions under out of control conditions, follow defined but difficult to know rules, specially at high temperatures showing high molecular complexity. It seems that the application of artificial intelligence techniques will help to predict which substances are produced given an initial chemical scenario. In this paper the k-nearest algorithm and its application to this problem will be studied.A database has been developed to manage reactive information independently from the algorithm or technique of AI to be applied. The most important information of the database are relations between substances present on the initial reactive scenario and the ones detected after reaction under out of control conditions occurred. Chemical substances contained in the database have been analysed by decomposing them into Benson’s Groups, which is thought to be the most adequate level of detail to preserve chemical information while establishing relations between non-identical substances.The Shepard’s modification of k-nearest neighbor algorithm has been used for the Boolean prediction of formation of a certain substance given a reactive scenario. Results show an accuracy above 95%.     

芦苇床中古细菌的群落多样性分析

为了描述剩余污泥稳定化芦苇床系统中有机质矿化、甲烷排放及相关微生物多样性之间的内在关系,采用PCR-DGGE技术分析了不同芦苇床、不同季节的稳定化污泥中古细菌群落结构及其多样性。序列分析发现,与DGGE条带序列亲缘关系最近的种属为未培养古细菌和未培养产甲烷古细菌。古细菌群落结构呈季节性变化,且同一季节不同芦苇床的群落结构存在一定差异。具有通气结构芦苇床的剩余污泥中产甲烷古细菌的丰度较低,同时甲烷排放量也较低,因此设置通气结构的芦苇床设计更合理。     

基于MapInfo的矿山通风安全信息系统开发

根据现代矿山通风系统对人机交互的要求,利用OLE技术和VisualBasic编程语言,对MapInfo进行二次开发,形成了矿山通风安全信息系统。所开发的系统集成了MapInfo强大的地图、信息、数据库等的管理功能,实现了电子地图与数据库的自动连接和双向查询,完成了信息的可视化管理,并可与生产监控、调度系统集成,用于指导煤矿安全生产,防止重大事故发生。该系统具有修改通风图、生成通风管理报表、备份数据等功能,同时还可以对通风系统中的防瓦斯突出、防尘、防火、安全管理、风机等日常管理数据进行处理,在实际应用中取得了良好的效果。     

大坝性态危险程度判别模型研究

通过分析大坝性态与大坝危险性间的关系,建立了基于logistic生长曲线的大坝危险程度评价模型,提出了基于大坝性态的各监测分析项目变权重确定方法,给出了一种依据大坝实时安全监测和分析结果综合评价大坝危险性程度的定量评价线性加权和技术,最后给出了一个大坝危险性定量分析案例,结果表明,本文方法具有可行性.     

20 Years on lessons learned from Piper Alpha. The evolution of concurrent and inherently safe design

It has now been well over 20 years since the North Sea Piper Alpha disaster in 1988. There have been many lessons learned; some documented others just etched in memory. The event chronicled many significant changes in the offshore industry. The emanating point for most sweeping changes has been the Cullen Report and the UK North Sea industry. This paper reviews some of the critical lessons and identifies many ‘secondary’ finer points that constitute important learnings. The paper looks at major changes instigated by step changes in safety criticality. It is argued that the ‘second tier’ modes of failure such as corrosion, materials degradation, environmental cracking, erosion, plant ergonomics, etc. need to be better examined. These mechanisms are dangerous threats to the integrity of deep subsea assets, and it is noted that such root causes of failure as witnessed or predicted have yet to be fully appraised. The authors’ use wide experiences and case histories to highlight such concerns, offering rational fit-for-purpose solutions. The industry disconnections between, urgency to build, knowledge transfer, and management of change, are refocused. Powerful advances in risk-based mechanical, process, materials, and corrosion engineering are emphasized and the use of key performance indicators (KPIs) are reasoned for best life-cycle integrity. To keep up with the pace of growth in the deepwater sector, methods of concurrent and inherently safe design have evolved in a world where the practicalities and costs of modification, repair and retrofit are extremely difficult. Hence getting it right at the outset is paramount. Thus the drive for purposeful investment, at design is more justifiable, than the traditional practice of postponing costs (and problems) to operations. In this way the ominous ‘gray’ zone between the two cost centers is better bridged for reasons of safety and commercial advantage.     

立井揭煤前测定煤层瓦斯压力的方法与实践

为了解决复杂环境下立井揭煤前煤层瓦斯压力的可靠测定,基于揭煤井筒瓦斯地质特征、煤岩体物理力学性质,应用COMSOL软件模拟揭煤工作面在接近目标煤层时,井筒周围煤岩的地应力分布特征,直观展现了目标煤层中的应力分布结果。模拟结果表明,立井工作面距煤层的垂直距离为7 m时,煤层中会形成一个近似于环形的卸压圈,卸压半径为16 m,因此煤层瓦斯压力测试孔的终孔位置应布置在井筒中心线16 m以外的原始地应力区,以保证测压点瓦斯压力不受揭煤井筒卸压区的影响,令测压结果准确可靠,从而更好地预测煤与瓦斯突出区域的危险性。同时,结合立井揭煤工作面的水文地质特征和井筒严重淋水情况,自主研发并应用了瓦斯测压孔"两堵一注"封孔材料及特定的封孔工艺,进一步保障了封孔质量和瓦斯压力测试结果的可靠性。最后,依据测压结束时测压管内的实际水压情况,对测压结果进行修正,并依据实测瓦斯含量,采用间接法对所测得的瓦斯压力进行验证,实测值在反算得到的瓦斯压力值域内,表明此方法有效可行。     

Risk indicators for major hazards on offshore installations

Major hazards risk indicators are proposed for offshore installations, based on what has been used by the Petroleum Safety Authority Norway for the Risk Level approach in the Norwegian offshore petroleum industry. Since 2002 also leading indicators are used, in the sense that indicators for barrier performance are included together with the lagging indicators. There are individual indicators for a number of barrier functions, including fire and gas detection, a number of safety valves, active fire protection and mustering of personnel. The performance of the leading indicators during several years of data collection as well as lessons learned from the project are discussed. This is followed by a review of how indicators may be used by individual companies, and how the lessons may be utilised by individual companies to develop risk indicators for individual installations as well as company wide indicators.     

采空区进风侧煤柱着火进行灭火时防止瓦斯爆炸的对策

以孔庄煤矿Ⅲ2水采区7337回风联络巷自然发火情况及处理经过为例,笔者介绍了在采空区瓦斯浓度较高情况下,采空区进风煤柱着火的火势发展情况与着火特点。分析灭火过程发生瓦斯爆炸的可能性;提出了在安全前提下灭火步骤、灭火措施和注意事项;总结了灭火工作中成功的经验与失败的教训,即在扑灭井下火灾过程中,必须做到:遵循“安全第一”的方针,制定科学、具体的灭火方案和正确、有效的灭火措施,要时刻加强火区气体成分检测,得出了防止瓦斯爆炸等一系列具有指导性的原则和行之有效的措施。