A framework addressing a safe ageing management in complex industrial sites: The Italian experience in «Seveso» establishments

In Europe, the Directive 2012/18/EU (Seveso III) strengthens the obligation to adopt a program assuring the integrity of critical equipment at major hazard establishments, by taking into account actual deterioration mechanisms (internal and external corrosion, erosion, thermal and mechanical fatigue, etc.). The program must cover all phases of the lifecycle and ensure a safe ageing of equipment, particularly when these are reaching the final stage of life. The effectiveness of the integrity program must be carefully assessed during the audits planned by the establishment's operator as well as by inspectors on behalf of the Competent Authorities. The adoption of a Risk Based Inspection scheme provides a valuable help to face this matter. The operator is, anyway, required a considerable effort to face at least three issues related to: (i) the understanding of concurring physical and chemical phenomena; (ii) the management of information associated with each individual component and its history, (iii) the appropriate measurement, including acquisition and management of data. There is a considerable difficulty in understanding these issues during Seveso inspections and external audits, because time and resources are often limited. For this reason, models and methods supporting the definition of the ageing status and trend in industrial sites are needed. This paper analyses the main factors affecting ageing. A framework for “ageing” assessment in complex industrial sites, including “Seveso” establishments, is proposed; then, its validation, by means of data collected during a testing phase carried out in Italy, is also given.     

Comparison of approaches to weighting of multiple criteria for selecting equipment to optimize performance and safety

Nowadays every piece of working equipment and tools has to comply with safety standards and laws. This study investigated multi-criteria methods for selecting working equipment in order to optimize performance and occupational safety. The multi-criteria decision-making (MDCM) method was applied to the problem of selecting optimal working equipment using four different criterion weighting approaches (direct weighting, revised Simos procedure, Fuller’s triangle and analytic hierarchy process). Groups of economic, technical and safety criteria were defined and five weighting scenarios were developed. Although the four weighting methods produced similar results, in some situations they produced different criterion weighting factors. The final output of the MCDM method was the identification of the optimal forklift in the five weighting scenarios. Although we have applied the MCDM method to a forklift selection problem, it can be applied to all sorts of working equipment in contexts where economic, technical and safety selection criteria can be identified.     

A Bayesian network-based approach for the assessment and management of ageing in major hazard establishments

Currently, there is an increasing attention towards ageing of industrial equipment, as the phenomenon has been recognised as a cause of severe accidents, recorded in the last years in many process establishments. Recent studies described ageing through a number of key-factors affecting the phenomenon by accelerating or slowing it down. The Italian Competent Authority for the prevention of chemical accidents (Seveso III Directive) adopted a short-cut method, accounting for the assessment of these factors, to evaluate the adequateness of ageing management during inspections at Seveso sites. In this paper, a Bayesian Network was developed, by using the data gathered during the first application of the short-cut method, with the aim to verify the robustness of the approach for ageing assessment and the validity of the a priori assumptions used in assessing the key-factors. The structure of the Bayesian network was established by using experts’ knowledge, whereas the Counting Learning algorithm was adopted to execute the parameter learning by means of the software Netica. The results showed that this network could effectively explore the complex logical and uncertain relationships amongst factors affecting equipment ageing. Results of the present study were exploited to improve the short-cut method.     

Procedure for assessing hardware safety integrity in legacy systems

Functional safety is related to the safety functions of a safety-related system that uses electrical/electronic/programmable (E/E/PE) devices such as sensors, logic solvers, and final elements. A legacy system is a safety-related system which offers safety functions but which was not designed to comply with the IEC 61508 standard. This paper presents a procedure for assessing the hardware safety integrity of a legacy system so as to confirm its functional safety. The procedure defines the systematic relationship between the safety function and hardware system using a function-structure map (FSM) and assesses the hardware safety integrity centered on the safety function. The proposed procedure is applied to a boiler control system of a fossil-fuel power plant.     

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.     

基于MCGS的矿井主提升设备安全监测系统的设计与实现

主提升设备的安全运行是矿山企业安全生产的先决条件之一,其安全监测亦是矿山企业安全监测的重点。基于主提升设备的安全监测现状,在充分调研国内主提升设备安全监测系统现状的基础上,通过需求分析,利用MCGS组态软件设计了金属矿山主提升设备安全监测系统,首次较全面地实现了主提升设备的实时在线监测。实际运行结果表明,系统能够满足现场监测要求,达到预期的监测效果。     

Utilizing Integrity Operating Windows (IOWs) for enhanced plant reliability & safety

Several industry codes, standards and recommended practices have been developed and utilized to maintain pressure equipment integrity and improve reliability. These industry standards focus heavily on inspections (time or risk based) and guidelines for operating equipment at conditions that enable a tolerable deterioration rate. RBI (risk based inspection), in effect, utilizes process conditions at a snapshot in time to recommend inspection strategies which can cover the span of the equipment's remaining life. On a day to day level, changes that occur in process conditions (excursions and upsets) are not fed back into the risk and criticality calculation. When such changes to operating conditions affect key process variables, new damage mechanisms could be introduced that affect the remaining life of an asset or accelerate existing damage mechanisms. The increase in risk resulting from these process changes goes unaccounted for until the effect of the deterioration is captured at the next inspection.Integrity Operating Windows (IOWs) are established limits for key process variables that can affect the integrity of the equipment if the process operation deviates from the established limits. The development of these IOWs requires fundamental understanding of the process and resulting damage mechanisms and is best facilitated by a team of corrosion and process engineers along with feedback from plant operators. A well-established IOW program is designed to provide real time notification of an increased risk to the integrity of an asset so that identified actions can be taken by the operators and/or plant managers proactively in a timely manner. Combining an RBI program with an IOW program can greatly increase its effectiveness and provide early recognition of equipment risks due to process changes. This paper will focus on the development of an IOW program and the benefits of combining it with a viable RBI program.     

Development and application of equipment maintenance and safety integrity management system

Equipment management in process industry in China essentially belongs to the traditional breakdown maintenance pattern, and the basic inspection/maintenance decision-making is weak. Equipment inspection/maintenance tasks are mainly based on the empirical or qualitative method, and it lacks identification and classification of critical equipment, so that maintenance resources can’t be reasonably allocated. Reliability, availability and safety of equipment are difficult to control and guarantee due to the existing maintenance deficiencies, maintenance surplus, potential danger and possible accidents. In order to ensure stable production and reduce operation cost, equipment maintenance and safety integrity management system (MSI) is established in this paper, which integrates ERP, MES, RBI, RCM, SIL and PMIS together. MSI can provide dynamic risk rank data, predictive maintenance data and RAM decision-making data, through which the personnel at all levels can grasp the risk state of equipment timely and accurately and optimize maintenance schedules to support the decision-making. The result of an engineering case shows that the system can improve reliability, availability, and safety, lower failure frequency, decrease failure consequences and make full use of maintenance resources, thus achieving the reasonable and positive result.     

The digital representation of safety systems at “Seveso” plants and its potential for improving risk management

At Seveso plants, duty holders must have a complex system for assessing and managing risks. The pillars of this system are the safety report and the safety management system, with a number of underlying documents. The strength of the system is the high standardization of these documents. Regulations, standard codes and guidelines define content, structure and formats. The weakness is the high complexity. Managers and workers perceive documents as difficult to understand and far from actual operations. Major threats for the credibility of documents (and therefore for the safety systems) come from the continuous organizational and technical changes, which in a short time can make most documents obsolete; as well as by near misses, which continuously show the holes in safety systems. A big effort is required to follow up the plant changes and the near misses. In order to help safety managers, a new software has been developed. At Seveso plants, it has been possible build an integrated digital representation, because all documents are perfectly structured. This representation may be used both for updating the relevant documents after a change and to improve documents after a near miss or an accident. In this way, safety documents are always up to date and trustworthy and the huge knowledge, which is usually hidden inside safety documents, is clearly revealed and revived. The approach is basically “knowledge based” and the intention is to provide safety managers with an easy and simple tool. IRISonLine is a software that has been developed by ISPESL to provide safety managers of “Seveso” establishments with a tool for improving the management of change and of near misses.     

TOPSIS法在职业危害综合控制方案决策中的应用

职业危害控制方案决策属于多属性决策,应用Topsis法对职业危害控制方案进行决策,可以满足不同工艺、不同作业条件、不同经济、技术水平企业选择适宜的职业危害控制方案的需求,以达到有效控制职业危害的目的。Topsis法用于企业职业危害控制方案进行决策具有较好的准确性、实用性,是一种较易于操作、客观的综合决策方法。     

论特种设备安全技术规范的基本安全要求

本文分析了特种设备安全技术规范的含义、法律地位和作用,介绍了欧盟指令中基本安全要求的主要内容以及和标准的关系等,重点论述了特种设备安全与风险的关系、特种设备基本安全要求的范围、本质安全的含义、特种设备损伤机理和失效模式分析的要求,提出了特种设备基本安全要求的确定原则。     

Main differences on European regulations in the frame of the Seveso Directive

Since the first Seveso Directive was issued 25 years ago, each Member State of the European Union developed own regulations to enforce its application. The lack of a common approach generated differences between Member States, or even between regions within a Member State, which in practical terms caused that establishments falling under the field of application of the Seveso Directive face a different level of requirements. This situation causes significantly different impact on social, technical and financial aspects.Factors like industrial background, accidental history, actual land use, social attitude towards risk, economical and political structures play an important role in how the decisions about hazardous activities are perceived and handled.Answering the question: “Is there a right methodology for the assessment of the risk of major accidents?” may be sterile or impossible. Many tools are appropriate and the main concern is to use them properly. Technically, the causes and consequences of, e.g., a fire in a port in Spain on the Mediterranean Sea or in the port of Basel (Switzerland) in the Rhine River could be assessed using the same methods and criteria, but this is not usually the case.This paper shows, with practical examples, the differences existing while applying different regulations in the field of prevention of major accidents and the potential effects that these differences may generate regarding the definition and management of emergency plans outside establishments.If the existing unequal situation is not faced, the comparative disagreements between Member States will prevail. Therefore, the application of the Seveso Directive will generate a different impact on the society, operators and regulators, and may become a factor which may cause a risk transfer between Member States. Efforts should be addressed to harmonize criteria in this subject.     

Regulations of major accident hazards control in Serbia and their implementation

The paper presents a brief summary of contents and implementation of the current Serbian regulations on the prevention and control of major accidents involving dangerous materials. Further, it discusses issues connected with implementation of the regulation, including inspection, review, and approval of safety reports. This regulation comprises legal requirements and methodological guidelines for risk analysis and preparation of emergency plans. Although the roots of the Serbian regulation are basically in the Seveso I Directive, this study revealed significant differences compared with current regulations and practice in Europe.     

Small enterprises and major hazards: How to develop an appropriate safety management system

Many small and medium sized enterprises (SMEs) are obliged to adopt a Safety Managements System (SMS) by the Directive 2012/18/EU for the control of Major Accident Hazards (Seveso III). The difficulties of implementing an SMS within a small sized work organization are well known by practitioners, including inspectors and auditors and have been discussed in many recent papers. In the present paper is discussed a new method, based on the bowtie model, to build an easy and effective SMS. The very core of this method is a “safety net model”, which is able to connect in a network all the tangible and intangible elements of safety, including equipment, operating instructions, procedures and safety documents. This safety model has been used as the core of a smart application, the strength of which is the workers' contribution. The application allows the users to build step by step an SMS. It starts from a first version based just on regulations and standard codes (version 0), then it integrates internal knowledge through the bowtie paradigm (version 1). Near misses' discussion is used to transfer actual workers' experience into the system, to get intermediate improvement of the SMS (version 1.x). At the end audit may be used to a major release of the SMS (version 2). The full cycle has been tested at two small Seveso establishments: a galvanic plant and small glue manufacturer.     

基于压电传感板的建筑疏散照明技术

在当今世界,电力、能源和安全是人们日常生活的基本要求。为了应对日益增长的能源需求,最终的解决办法是实施可再生能源,然后将其用于人类的安全。可再生能源需要以它们各自正确的方式实施。研究基于压电传感器片的迈步发电装置,并演示了如何利用这些能量实现建筑物疏散照明。我们在传感器的下方和顶部分别固定了木板和可移动网螺栓,利用压电传感器系统,行人可以通过迈步向发电装置施加电能,另外,将硅凝胶粘贴在位于下部木板空洞中的所有传感器顶部。当有人踩到板上时,就会自动施加压力。在木板的顶部和底部设置了一个孔,以便随时调整在底部和顶板之间安装的可移动网螺栓。烟雾传感器用于启动灯光。使用这种设备,我们实现了建筑物疏散路径上的LED灯正常运行。结果表明,这种安全发电的设计和方法具有一定的实用价值,同时也满足了全球对能源的需求。     

Analysis of underlying causes of investigated loss of containment incidents in Dutch Seveso plants using the Storybuilder method

In the Netherlands there are around 400 “Seveso” sites that fall under the Dutch Major Hazards Decree (BRZO) 1999. Between 2006 and 2010 the Dutch Labour Inspectorate's Directorate for Major Hazard Control completed investigations of 118 loss of containment incidents involving hazardous substances from this group. On the basis of investigation reports the incidents were entered in a tailor-made tool called Storybuilder developed for the Dutch Ministry of Social Affairs and Employment for identifying the dominant patterns of technical safety barrier failures, barrier task failures and underlying management causes associated with the resulting loss of control events. The model is a bow-tie structure with six lines of defence, three on either side of the central loss of containment event. In the first line of defence, failures in the safety barriers leading to loss of control events were primarily equipment condition failures, pre start-up and safeguarding failures and process deviations such as pressure and flow failures. These deviations, which should have been recovered while still within the safe envelope of operation, were missed primarily because of inadequate indication signals that the deviations have occurred. Through failures of subsequent lines of defence they are developing into serious incidents. Overall, task failures are principally failures to provide adequate technical safety barriers and failures to operate provided barriers appropriately. Underlying management delivery failures were mainly found in equipment specifications and provisions, procedures and competence. The competence delivery system is especially important for identifying equipment condition, equipment isolation for maintenance, pre-start-up status and process deviations. Human errors associated with operating barriers were identified in fifty per cent of cases, were mostly mistakes and feature primarily in failure to prevent deviations and subsequently recover them. Loss of control associated with loss of containment was primarily due to the containment being bypassed (72% of incidents) and less to material strength failures (28%). Transfer pipework, connections in process plant and relief valves are the most frequent release points and the dominant release material is extremely flammable. It is concluded that the analysis of a large number of incidents in Storybuilder can support the quantification of underlying causes and provide evidence of where the weak points exist in major hazard control in the prevention of major accidents.     

核电厂人因事故预防的定量化决策

人因事故的分析与预防是核电厂安全运行和管理的重要内容。笔者提出的系统安全性层次分析法主要从两种角度考虑系统的安全性:专家能力权值和安全性矩阵的建立。采用专家判断矩阵确定事故原因对系统安全性的重要度排序。举例某核电厂事故定量分析进行说明,在对事故进行原因分析基础上,构建事故影响因素层次模型,利用层次分析法分析得出事故原因重要度排序由高到低依次为组织管理、操作人员、人机界面、培训与设备状态,并据此提出了相应的预防与改进措施,为安全性要求较高的复杂工业系统提供事故预防的定量化决策依据。     

桥梁建设的安全重心——架桥机安全运行探讨

对铁路、公路桥梁建设中使用的关键设备——架桥机事故及安全隐患进行统计、总结,结合架桥机的结构特点、现场环境、使用状况进行安全使用管理分析。阐明对结构复杂、作业环境差、操作繁琐的机电液一体化的大型设备——架桥机现场操作安全管理的核心是各操作步骤中对安全状况的检查确认;在架桥机安全使用条件、操作人员、安全检查、安全试验等方面提出要求,对架桥机吊梁、过孔、变跨、收尾、维护保养等作业过程的安全操作进行规范,指出对架桥机现场施工科学安全监督管理的内容,全面、系统地完善架桥机安全使用管理体系。     

Optimization of test interval for ageing equipment: A multi-objective genetic algorithm approach

Reducing the unavailability of safety systems at nuclear power plants, by utilizing the probabilistic safety assessment (PSA) methodology, is one of the prime goals in the nuclear industry. In that sense, optimization of test and maintenance activities, which are defined within the technical specifications, represents quite popular and interesting domain. Obtaining optimal test and maintenance schedule is of great significance for improving system availability and performance as well as plant availability in general.On the other side, equipment aging has gradually become a major concern in the nuclear industry since the number of safety systems components, that are approaching their wear-out stage, is rising fast. Nuclear power plants life management programs, considering safety components aging, are being developed and employed. The immense uncertainty associated to the available component aging rates databases poses significant difficulties in the process of incorporation and quantification of the aging effect within the PSA and, subsequently, in the decision-making process.In this paper, an approach for optimization of surveillance test interval of standby equipment with highly uncertain aging parameters, based on genetic algorithm technique and PSA, is presented. A standard standby safety system in nuclear power plant is selected as a case study. A Monte Carlo simulation-based approach is used to assess uncertainty propagation on system level. Optimal test interval is derived on the basis of minimal system unavailability and minimal impact of components aging parameters uncertainty. The results obtained in this application indicate the fact that risk-informed surveillance requirements differ from existing ones in technical specifications as well as show the importance of considering aging data uncertainties in component aging modeling.     

The impact of the COVID-19 pandemic on the safety management in Italian Seveso industries

The paper discusses the impact of the COVID-19 pandemic on the Italian chemical and process industries, where Directive 2012/18/EU Seveso III, for the control of Major Accident Hazard (MAH), is enforced. The Safety Management System (SMS) for the control of MAH, which has been mandatory for 20 years in Italian Seveso Establishments, has been highly stressed by the external pressure, related in some way to the COVID-19 pandemic. Fairly, most companies, in particular in oil and gas sectors, have demonstrated an adequate capability to reconcile operation continuity and health requirements. This experience is providing the establishment operators and the regulators with valuable suggestions for the improvements of the SMS-MAH. Within this framework, an innovative organisational resilience model is proposed, aiming at the development of a higher capability to face future new crisis. The current SMS-MAH already includes some basic pillars to enhance resilience, which were valuable during the pandemic crisis, but a full and rationale development is still needed. Starting from the first pandemic phase experience, this paper presents a novel tool to assess the degree of “resilience” of a SMS-MAH. It is based on a questionnaire, featuring 25 questions grouped into eight items, according to the typical SMS-MAH structure. A two level AHP model has been developed in order to define the weights to be assigned to each point. The AHP panel included industrial practitioners, regulators, authorities and researchers. The results are based on the COVID-19 experience and consequently the developed model is tailored to face health emergencies, but the approach may be easily transferred to other external crises.