Search

The utilization of risk acceptance criteria (RAC) can help a business to judge whether the risk level concerning any process involved in its working environment is acceptable or not, especially when the risk has a significant societal impact. Thus, the main intention of this study is to make known the current state-of-the-art concerning RACs and to propose new interpretations of it by surveying, for first time, the scientific literature about the RACs associated with the occupational health and safety (OHS) risk-assessment methodologies (RAA). A second objective of this work is the attainment of a prediction for the evolution of the quantity of the publications concerning OHS-RACs, and a third one is the derivation of an algorithm (via a flow-chart) in order to illustrate the process of the formation of new OHS-RACs. The work consists of two parts, (a) exploring and presenting methods of developing RACs in OHS; (b) classifying, analyzing, and benchmarking relevant published scientific articles by surveying the Scopus data base with proper search-hints, through a time interval of 20 years (January2000–December 2019). The review has defined a plethora of RAC-papers with reference to OHS, which is a remarkable percentage in comparison with the other fields aggregated, and this outcome proves that the issue of utilizing RACs is fundamental for the field of OHS. Additionally, it has been deduced that, day after day, there is an increasing tendency for the scientific community to develop and use RACs in the field of occupational safety, as this is evident by their frequent reference to the risk analysis and assessment (RAA) process. Our specific research methodology has been compatible with the PRISMA protocol. A prediction for the evolution of the quantity of the OHS-RAC publications is also given by confirming the Poisson stochastic process. Finally, we propose a generic guideline framework that can contribute to the establishment of new empirically-generated OHS-RACs.

A gas explosion is one of the main hazards of underground utility tunnels (UUTs), and the explosion overpressure can have catastrophic consequences. A pressure relief opening (PRO) can be an effective method of reducing the risk of an explosion. However, most existing UUTs in China are not configurated with a PRO. Therefore, the present study proposes a risk-based PRO design to explore the optimal layout for UUTs. Both dispersion and explosion simulations using Flame ACceleration Simulator (FLACS) were conducted to calculate the maximum overpressures, and then probabilistic studies were applied for risk analysis. The FLACS simulation results show that PROs can significantly reduce the maximum explosion overpressure from 2.23 bar to 1.97 bar. An ALARP (As Low As Reasonably Practicable) concept was applied to provide a risk reference for the design of a PRO in UUTs.

Major chemical process accidents over the recent past decades have led to the formulation and enforcement of land-use planning (LUP) practices across many countries, so as to mitigate the public risk emanating from major chemical hazard installations. The present paper presents an approach to deciding land-use policy founded on integrated local risk-acceptance criteria and an attendant societal cost-benefit analysis. The application of the proposed approach is demonstrated by a case study of an example greenfield industrial facility for which the adjoining land is subject to strictures of LUP policy. The context is chosen to be that of India, which is an emergent economy that is beset with unique challenges for balancing land-use between agrarian and industrial use. The societal costs and benefits are computed employing macro-economic indicators; the former comprise opportunity cost of land restricted for development, while the benefit is comprised of the cumulative wealth generation due to economic development of the jurisdiction over the facility life time. The value of the benefit to cost ratio is found to be highest corresponding to a LUP based on a relatively relaxed risk acceptance criterion with As Low as Reasonably Practicable (ALARP) limits of 10−6–10−4/yr for public individual risk. The primary reason for this outcome is that, in comparison to a developed economy, land prices in India are relatively high vis-a-vis labour productivity and wages. This shifts the LUP choice towards the policy which involves least land-use restrictions against non-agrarian, commercial developments in the vicinity of major hazard installations. It is also demonstrated that if the per capita GDP values corresponded to those of developed economies, a LUP policy based on a more stringent risk acceptance criterion may be affordable for the society. An additional significant finding of the study is that the Value of Statistical Life of humans makes a relatively minor contribution to the societal cost-benefit analysis. Thus, its value as a determinant to LUP decision may be relatively limited. This essentially underscores the idea that the broader objective of LUP need be to simultaneously foster economic development and minimise human and other critical losses.

In light of the complex operating environment and high maintenance cost of offshore wind power projects, a risk evaluation system is established in accordance with the risk’s features and sources during the operation period of offshore wind power projects. On grounds of the risk evaluation system, a risk assessment method for offshore wind power projects during the operation period is put forward based on the multi-level fuzzy comprehensive evaluation method, and a specific project in the South China Sea is evaluated with the assessment model. The results showed that the risk probability is moderate to low, the consequences of the hazards are moderate, and the comprehensive risk rating is moderate for the assessed project during the operation period. It is necessary to follow the ALARP (As Low As Reasonably Practicable) principle to mitigate the risk. The risk level of offshore wind farms during the operation period can be judged using the evaluation method to provide technical support for prevention and emergency response of the accidents related to the offshore wind power projects.

In the context of the hierarchy of risk controls, warnings, administrative controls, and personal protective equipment are sometimes referred to as lower order controls. In practice, the effectiveness of these controls can be overestimated due to a misunderstanding of the human factors that affect error likelihood in their implementation. This paper explores one human factor: the limitation of attention on residual risk inherent in lower order controls. The limitation of attention has implications for identifying hazards, assessing risk, taking appropriate actions based on warnings, executing safe work practices, and proper selection and use of personal protective equipment. Raising awareness and improved understanding of these topics can enable more effective risk assessment, quantification of residual risk, and more effective selection and combination of risk controls to achieve risk as low as reasonably practicable.

An application of the Bayesian Belief Network (BBN) modelling is presented as a support in establishing process safety related key performance indicators (KPIs) for business management purposes. A relation to the managers' trust into results of risk analysis results is made. The case study deals with a possible spill, ignition, and explosion of methanol during a ship tanker unloading operation at the liquid cargo terminal at the port of Koper, Slovenia. Considerations of business impacts of such a major accident proved to be of particular relevance to the top management. Besides direct financial costs indirect economic impacts, like longer business interruption and impact to reputation, caused stronger concern due to their possible overall financial scope. This finding triggered a management requirement for establishing new, direct, measurable KPIs in association with multiple organizational safety improvement measures. Despite their small individual contribution to overall risk reduction, they are altogether effective in better understanding of the benefits of risk analysis for business. The BBN modelling assisted in identifying dominant contributors to key failure events, which was the guidance for proposing the meaningful, measurable business relevant KPIs. Benefits of such KPIs rely on regular monitoring by mid and top managers.

In process industry, SIL determination is a risk assessment process through which target Safety Integrity Levels (SIL) are allocated to Safety Instrumented Functions (SIF). A target SIL represents the significance of the hazard against which the SIF protects the plant. This paper introduces new SIL determination methods by taking an optimization approach. Unlike the conventional methods, which are generally focused on calculating the gap between the existing and tolerable levels of risk, the methods introduced in this paper are aimed at optimizing the marginal cost or the benefit-cost ratio. By incorporating the cost factor into the SIL determination process, these methods deliver the most reasonably practicable solutions that can minimize the risk while taking into account the cost of solution. The new methods are formulated for corporate risk and the risk to community (i.e. ALARP). Both methods are derived for demand and continuous modes of SIF operation. Furthermore, a new Safety Index is introduced to combine the SIL and the average Probability of Failure on Demand (PFD) or Frequency of Failure per Hour (PFH). The application of the mathematical models is demonstrated through a practical example from power industry.

Despite the rapid development of risk analysis, there is a relative absence of risk criteria for dams in developing countries recently, which restrained the practical application of the research results. This paper proposes guidelines for establishing risk criteria of dams in developing countries in considering the coordination of social, economic and engineering factors, then establishes a method of targeted analysis and demonstrates relevant parameters selected according to the ALARP principle and F-N curves, using China as an example. Different individual life risk criteria are established based on different safety levels for existing dams and newly built dams. Social life risk criteria and economic risk criteria are established on the basis of the different safety levels of all size reservoirs, the seriousness of the consequences of accidents, and the acceptability of social risks. The process of establishing risk criteria of dams and the analysis of the parameters demonstrated in this paper are meaningful to provide a reference and promote the required level of management for developing countries.

An overview of the GeoSafe 2016 Symposium topic is provided using the example of large concrete dams for purposes of illustration. It is essential that the risks associated with large dams be evaluated rigorously and managed proactively at all stages of their lives so that the risk of failure remains As Low As Reasonably Practicable (ALARP). Rock engineering features of large concrete dams that require particular attention, assessment and monitoring during the investigation, design, construction, initial filling, in-service operation, and subsequent repair and upgrade stages of the lives of concrete dams are identified and illustrated by examples from recorded experiences. A number of major concrete dam failures, including that of the St. Francis dam, California, U.S.A., in 1928, have led to significant developments in rock mechanics and rock engineering knowledge and techniques, as well as in dam design and review processes. More recent advances include a range of analytical, numerical modelling, probabilistic, reliability, failure mode and risk assessment approaches.

BACKGROUND In order to evaluate occupational disorders and ergonomic problems in a workplace, Multiple Criteria Decision Making (MCDM) problem solving methods such as Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) can be utilized. OBJECTIVE In this paper, Musculoskeletal Disorder (MSD) risk factors were evaluated in a manufacturing company in Iran by a method called Assessment of Repetitive Tasks (ART) of the upper limbs integrated with Fuzzy TOPSIS in order to prioritize the corrective actions. METHODS This study was done with a descriptive-analytical approach. The company under study had 240 employees who were working in seven different shops. Out of all tasks, 13 tasks were included in the study. Required information was gathered by a demographic questionnaire and ART method. Also, Fuzzy TOPSIS was utilized for the prioritization of the company shops based on the ergonomic control needs. RESULTS Data analysis from ART indicated that 74.6% of the reviewed tasks were high risk. Based on the F- TOPSIS-ART results, Production shop prioritized as the highest need for MSD control. CONCLUSIONS Because there is time and financial resources limit in ergonomic control activities, a fuzzy prioritization approach such as Fuzzy TOPSIS ART can be used to take advantage of the available resources and control risks to as low as reasonably practicable (ALARP) level.

When assessing explosion risks of super-large offshore structures such as Floating Liquefied Natural Gas (FLNG) facilities, there are neither design rules nor industry standards available as FLNG is a new technology. Meanwhile, a large amount of Computational Fluid Dynamic (CFD) calculation time is required due to its super-large size and highly complicated topside structures. A multi-level explosion risk analysis method (MLERA) is developed in this paper, which divides the whole structure into subsections and applies detailed CFD calculations only to the areas with the highest level of potential risks so that the computational time can be reduced to a realistic and acceptable level. The MLERA includes three levels, which are qualitative risk screening, semi-quantitative risk classification, and quantitative risk assessment. A CFD tool called FLACS is used as a calculation tool for detailed risk quantification, and an ALARP (as low as reasonably practical) method is selected as a calibration tool and used to determine the acceptance of the explosion risk. Meanwhile, since the current design standards for normal offshore platforms are not sufficient for super-large structures, during the risk screening and risk classification processes, safety barriers are used as extra risk indicators in addition to the traditional ones. A case study is conducted based on a cylindrical FLNG model, and the result of the case study proves that the proposed MLERA method is able to save a large amount of computational time.

Purpose: The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference.Methods and Materials: A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement.Results: Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed.Conclusions: Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk. (C) 2019 Elsevier Inc. All rights reserved.

Projects aimed at reducing water and/or energy consumption present technical and economic complexity profiles that require the analysis of the many components of investment risk. Risk analysis is essential to express judgements on the economic convenience of projects in the water-energy sectors. It is important to study actions for the mitigation of investment risk, so as to report the residual risk within tolerability limits. The integration of the as low as reasonably practicable (ALARP) logic with the cost-benefit analysis allows to define a protocol for the acceptance of the residual investment risk.

Nowadays, different industries such as nuclear, automotive, process, chemical, and oil & gas industry, must meet specific requirements in order to keep and reduce safety risks to as low as reasonably practicable (ALARP) level. As a result, the number of electrical/electronic/programmable electronic safety-related systems (E/E/PES) to control, prevent and mitigate hazardous events has increased. Moreover, new guidelines and procedures have been developed to guarantee the availability and function of safety systems over their service life. Based on Markov processes, this paper proposes a reliability model to assess the integrity and verify the design of E/E/PES safety-related systems. The average probability of failure on demand (PFD avg ) and Safety Integrity Level (SIL), are used to determine the reliability performance of an E/E/PES in a low demand mode of operation in accordance with the functional safety principles of the IEC 61508 and IEC 61511 standards.

ObjectivesTo examine general practitioner (GP) understanding of the never event (NE) concept in general practice, and to identify potential enablers and barriers to implementation in UK general practice.DesignQualitative study using focus groups. The data were analysed thematically and were informed by the normalisation process theory.SettingGeneral practice in Northwest England and Southwest Scotland.Participants25 GPs took part in five focus groups. 13 GPs were female and 12 male with an age range of 28–60.ResultsThe NE approach of avoiding serious preventable adverse outcomes from healthcare fitted with participants expectations of the delivery of care but the implementation of strategies to prevent the specific NE was considered complex and variable. The main themes identified participants’ understandings and perceived limitations of the NE concept; the embedded layers of responsibility to implement NE within practices and the work required for implementation within general practices. Participants’ accounts highlighted the differential nature of work in general practice and that the implementation of initiatives to address specific NE should be situated within a learning and systems approach to implementation. Some NEs were considered more relevant and amenable to simple solutions than others which could influence implementation.ConclusionsThe NE concept was considered overall an important approach to help address key primary care patient safety issues. The utility of individual NEs may vary depending on the complexity of the initiatives that would be needed to manage related risks to as low as reasonably practicable.

En el territorio colombiano, las condiciones meteorológicas están principalmente condicionadas por la zona de confluencia intertropical. Debido a esto, Colombia es una de las regiones con mayor actividad de rayos en el mundo, lo cual se refleja en un considerable número de muertos y heridos, y se asocia con la existencia de riesgo para la población en general. Este trabajo final de maestría evalúa y analiza el riesgo en seres humanos causado por rayos teniendo en cuenta las condiciones climatológicas y geográficas de Colombia (departamentos y subregiones naturales), la actividad de rayos en el país y la información obtenida a partir de diversas fuentes (gubernamentales y privadas). En primera instancia, se llevó a cabo una revisión para unificar las definiciones de riesgo existentes en la literatura y se identificaron como factores que inciden en el riesgo por rayos: exposición, vulnerabilidad y peligrosidad (Nivel I). Este último factor, compuesto por distribución del suceso, intervalo de recurrencia y grado de peligrosidad (Nivel 2). Luego, se relacionaron los factores de riesgo identificados con varios parámetros del rayo. De esta manera, los factores que corresponden a la peligrosidad se asociaron a la densidad de descargas a tierra (DDT), el nivel ceráunico (NC) y la severidad o tormenta severa (S). Por su parte, la exposición se asoció a la densidad poblacional y la vulnerabilidad con todos los casos que fueron reportados como víctimas mortales por rayos. Posteriormente, se desarrollaron y aplicaron varias metodologías para determinar cuantitativamente los factores de riesgo. En la primera metodología se definieron e identificaron veinte subregiones naturales en Colombia. En la segunda, a partir de las estadísticas que tiene el Departamento Administrativo Nacional de Estadísticas (DANE), se encontró un total de 1313 muertes a causa de rayos para el periodo comprendido entre 1997 y 2017. Paralelo a esto, y para el mismo periodo de tiempo, se obtuvo la densidad de población a nivel nacional y por subregiones. La tercera metodología consistió en calcular la DDT, el NC y la S para toda Colombia. Estos parámetros del rayo fueron obtenidos para el periodo 2012-2017 a partir de la información suministrada por la red LINET®, administrada por la empresa Keraunos SAS. En la parte final de este trabajo se desarrolló un estudio global de riesgo por rayos. Para esto, se analizó el riesgo tolerable por rayos haciendo uso de las curvas F-N, encontrando que el riesgo social en las subregiones naturales y, en general, en toda Colombia, se encuentra dentro del límite aceptable, según el valor típico de riesgo tolerable registrado en la Norma Técnica Colombiana NTC 4552-2. Finalmente, se plantean tres escenarios (modelos matemáticos) para la estimación del riesgo total por rayos, los cuales combinan los factores de riesgo previamente cuantificados (exposición, vulnerabilidad y peligrosidad). Luego de comparar los resultados obtenidos con los tres modelos se evidenció que, al hacer uso de cualquiera de las fórmulas, las subregiones naturales de Colombia que presentaron un mayor riesgo por rayos durante el periodo 2012-2017 fueron Llanura Caribe (LLC), Montaña Noroeste (MNOE), Valle del Cauca (VC) y Valle del Magdalena Medio (VMM). In the Colombian territory, the meteorological conditions are mainly conditioned by the intertropical convergence zone. Due to this, Colombia is one of the regions with the highest activity of lightnings in the world, which is reflected in a considerable number of deaths and injuries, and it is associated with the existence of risk for the population. This final master's degree project evaluates and analyzes the risk in humans caused by lightnings, considering the climatic and geographical conditions of Colombia (departments and natural subregions), lightning activity in the country and information obtained from several sources (governmental and private). In the first instance, a review was carried out to unify the definitions of risk existing in the literature and the factors that affect the risk of lightnings were identified: exposure, vulnerability and dangerousness (Level I). This last factor, composed by distribution of the event, recurrence interval and degree of danger (Level 2). Then, the identified risk factors were related to various parameters of the lightning. In this way, the factors that correspond to the dangerousness were associated with the ground flash density (GFD), the keraunic level (KL) and the severity or severe storm (S). On the other hand, the exposure was associated with population density and the vulnerability was related to all the cases that were reported as fatalities by lightnings. Subsequently, several methodologies were developed and applied to quantitatively determine the risk factors. In the first methodology, twenty natural subregions were defined and identified in Colombia. In the second one, from the statistics held by the Departamento Administrativo Nacional de Estadisticas (DANE), a total of 1313 deaths by lightnings was found for the period between 1997 and 2017. Parallel to this, for the same period of time, population density was obtained at national level and by subregions. The third methodology consisted in calculating the GFS, the KL and the S for all of Colombia. These lightning parameters were obtained for the period 2012-2017 from the information provided by the LINET® network, managed by the company Keraunos SAS. In the final part of this work, a global study of lightning risk was developed. For this, the tolerable risk was analyzed using the F-N curves, finding that the social risk of lightnings in the natural subregions and, in general, in all of Colombia, is within the acceptable limit, according to the typical value of tolerable risk registered in the Colombian Technical Standard NTC 4552-2. Finally, three scenarios (mathematical models) are proposed for estimating the total risk of lightnings, which combine the previously quantified risk factors (exposure, vulnerability and dangerousness). After comparing the results obtained with the three models, it was evident that, when making use of any of the formulas, the natural subregions of Colombia that presented the highest risk of lightnings during the 2012-2017 period were Llanura Caribe (LLC), Montaña Noroeste (MNOE), Valle del Cauca (VC) y Valle del Magdalena Medio (VMM). Magister en Ingeniería Eléctrica Maestría

Fire safety engineering designs should comply with the ALARP requirement, meaning that fire safety measures should be implemented to ensure that fire risks are As Low As Reasonably Practicable (ALARP). However, previous approaches have often been contradictory or unclear, especially with respect to the concepts of risk aversion, the valuation of risk to life, the concept of disproportionality, and the need to take into account monetary benefits resulting from life safety investments. First, the As Low As Reasonably Practicable (ALARP) criterion is specified to a societal, risk-neutral, and scalar cost-benefit analysis in the field of fire safety engineering. This is done to overcome the shortcomings in current practice with respect to utilizing the ALARP criterion for Probabilistic Risk Assessment (PRA). Second, the ethical dilemma of the valuation of risk to human lives is addressed by application of the Life Quality Index (LQI), as has been suggested in the field of structural engineering through the recent ISO 2394:2015 standard. Contrary to the existing literature, the proposed interpretation for the ALARP requirement corresponds to an application of the LQI maximum societal benefit criterion. This ensures that safety resources are allocated so as to maximize the number of lives saved, and implies that the ALARP criterion results in stronger minimum requirements for life safety investments, i.e. societal lower bound investment levels. Third, the valuation of costs and benefits by the fire safety engineer is addressed by emphasizing the duty of care, and by specifying a benchmark criterion for the objective, diligent, and competent fire safety professional. This reinforces self-reflection amongst fire safety professionals, and diminishes the need for often unjustified or poorly specified disproportionality factors. Finally, the relationship between fire safety design and private actor cost-optimisation considerations is discussed, and the presented concepts are illustrated using three examples. These clarify the application of the presented concepts and demonstrate how the societal ALARP requirement interacts with the (safety) preferences of private investors. The examples highlight the importance of the societal ALARP evaluation and show that this governs the safety investment when the private investor values damages low, applies a high discount rate, or takes into account indirect costs (e.g. aesthetic costs) related to the safety investment.

This chapter describes the implementation process of the F-N curve, which makes possible to represent the societal risk and subsequently verify its acceptance with respect to the ALARP criterion. The F-N curve is evaluated starting from the frequencies of occurrence of the accidental events and the number of fatalities determined by each accidental scenario.

The safety problems of nuclear power plants are getting more and more serious. Digital control system is widely used in nuclear power plants in China, which reduces the possibility of human error and reduces the workload of operators, but at the same time brings new risks to the operation of nuclear power plants. The network security law was formally implemented in June 1, 2017. The baselines for nuclear power plant networks should not be considered only economic. Security is the most important thing. Input or increase network security equipment, it does not necessarily lead to the promotion of network security. This article analyzes the network security risks of nuclear power plants based on the ALARP Criteria, discusses the balance between inputs and risks, and proposes network risk management recommendations for nuclear power plant network security.

This chapter illustrates a multi-level explosion risk analysis method for super-large oil and gas facilities, so as of the FLNG platform. Three levels of risk analyses, i.e., a qualitative risk screening, a semi-quantitative risk classification and a quantitative risk assessment, are implemented. The CFD method is applied for detailed risk quantification, and an as low as reasonably practical (ALARP) method is adopted as a calibration tool. Safety barriers are introduced as extra risk indicators and a case study is conducted based on a cylindrical FLNG model.

Starting with explanations of hazard and risk, detailed discussions have been presented to identify the requirements for functional independence for BPCS and SIS, which is a requirement for a plant lifecycle analysis. HAZOP-type hazard analysis is best suited for power plant applications, and has been described to identify hazards and come out with control measures. As a part of risk analysis likelihood, consequence and exposure details have been discussed. Risk register, risk graphs, ALARP, and other methods have been covered. Detailed discussions on plant lifecycle analysis in line with IEC 61508/61511 and ISA 84.00.00 have been presented, including various stages of the standards including SRS validation and verification. Issues related to failure categories and development of fault-tolerant designs that are required for the design of SIF and SIS with suitable PFDs/SIL have been discussed. Various methods have been discussed for SIL determination. Comprehensive discussions have been presented on SIS alarms, alarm lifecycles, and rationalization. As part of the SIS component, detailed accounts have been presented on field sensors, logic solvers, and final control elements, including PST and FST. The controversy over integrated or separate BPCS and SIS networks has been addressed. Focus has also been placed on the enclosure protection class.

Legacy risks from infrastructures and industrial installations often reveal themselves when a potential for failure has been discovered much later than at the stage of the design and construction of a structure. In which case, there might already be a problem with the legacy installation, or even a crisis, without having had an accident. When the hazard cannot be taken away, the question arises as to how much effort, if any, should be spent on improving the situation. The usefulness of the three archetypical approaches to this problem: setting a standard, the as low as reasonably practicable approach and a case-by-case discourse approach are discussed for their applicability for these legacy risks. Although it would be desirable to retrofit legacy risks to previously set legal requirements as is the case when acceptability limits are set in law or demonstration of ALARP (As Low As Reasonably Achievable) is demanded, it may be impossible to reduce the residual risk to an otherwise acceptable level without taking away or replacing the infrastructure, which is not acceptable either. Therefore in conclusion the only available solution to persistent legacy risk problems seems to be to have a thorough discussion with all relevant stakeholders until an agreement is in some way found.

Risk-based design is an essential strategy for enhancing the safety performance of road infrastructure during its operation stage. However, conventional risk-based design generally considers the risk of a single type of disaster, which is insufficient for assessing the multi-hazard risk of the road infrastructure in an extreme environment. In this study, a synthesis method, the risk-informed knowledge-based analytical method (RKAM) for multi-hazard risk assessment, is proposed for the road infrastructure. The RKAM uses risk mapping techniques and the as low as reasonably practicable (ALARP) principle. Expert knowledge is utilized in order to overcome the scarcity of historical data. The RKAM is applied to the Tuoba–Qamdo Highway project in the Qinghai–Tibet Plateau of China to assess the overall risks of causalities and structural damages caused by traffic accidents, fire accidents, and landslide disasters. The results of this case study show the capabilities of RKAM to generate a synthesis assessment of the expected loss by multi-hazard disasters, which provides valuable information for selecting the most appropriate design of road infrastructure.

Structural fire safety requirements implicitly balance up-front investments in materials (protection or element sizing) with improved performance (loss reductions) in the unlikely event of a fire. For traditional prescriptive fire safety recommendations, the underlying target safety levels are not clear to the designer, nor is the associated balancing of risk and investment costs. It is discussed that traditional (structural) fire safety design is deterministic, with the safety foundation premised upon the collective experience of the profession. However, it is noted that building forms are increasingly uncommon in nature, due to material choice, height, failure consequences, etc. Within the framework presented in PD 7974–7:2019 there is an expectation that probabilistic risk assessment (PRA) methods be employed to demonstrate adequate safety for cases where the collective experience of the profession cannot be called upon to guide design approaches. In doing so, any design must be demonstrated to be tolerable to society, and the residual risk as low as is reasonably practicable (ALARP). In support of the PD 7974–7:2019 framework, the paper assesses the failure probabilities of isolated steel elements in function of insulation thickness, utilization, load ratio and (mean) fire load. In support of a generalized definition of target safety levels for structural fire safety engineering, optimum target safety levels for insulated steel beams are then determined as a function of the fire characteristics by applying life-time cost optimization (LCO) techniques. The LCO results in an assessment of the optimum investment level as a function of the fire, and damage and investment cost parameters characterizing the building. It is intended that the current contribution can be a steppingstone towards rational and validated reliability targets for performance-based design (PBD) in structural fire safety engineering.

This research is aimed at providing insight into various nuclear regimes for countries that are looking to start a nuclear energy programme but have yet to develop such regimes, as well as those with a well-established nuclear programme. It will also evaluate the value of independence of nuclear regulators with regards nuclear safety whether independence on its own is of any value to the society or the nuclear regulator needs to be more effective in giving effect to the objective and mandate it was established for. Based on the fact that there is currently no yardstick available to measure the effectiveness of the nuclear regulator in carrying out its functions, a number of pointers are listed which failed will indicate the ineffectiveness of the nuclear regulators in protecting the public, environment and the property from the harmful effects of radiation. It will also highlight the value of flexibility in nuclear licensing in order to find the right fit between the nuclear regulatory circumstances and not sticking to the design of the nuclear regulatory regimes when they are not relevant. In addition, this paper will indicate the advantages and disadvantages of various regulatory regimes applicable to the nuclear regulatory authority, and most importantly show the fundamental difference between ‘as low as reasonably achievable, (ALARA), economic and social factors being taken into account’ and ‘as low as reasonably practicable’ (ALARP), and why these two cannot be used interchangeably.

This paper identifies key areas of concern regarding the use of deferral as a maintenance management tool. As the national regulator for offshore petroleum operations and greenhouse gas storage activities, National Offshore Petroleum Safety and Environmental Management Authority is uniquely positioned to observe the various processes and tools applied by industry in the management of maintenance for offshore facilities, including impacts on safety and the environment, while acknowledging the need for business sustainability. This Extended Abstract provides a regulator’s perspective on the use of ‘maintenance deferral’ by industry as a tool for balancing competing priorities, while ensuring the risks to people and the environment are reduced to a level that is as low as reasonably practicable. It highlights the pitfalls of maintenance deferral that may negatively influence safety and environmental performance over the life of a facility (from construction through to decommissioning) as well as on the business’ bottom line. Learnings identified from non-compliances, improvement recommendations and incidents to promote efficient and effective learning are shared to further enhance existing good practices across the industry.

The acceleration of decommissioning activities in recent times has expedited the need to decommission responsibly and sustainably. Decommissioning activities are increasingly under public scrutiny, yet in many regions there remains a lack of legislation, regulatory guidance, and practical experience in implementing decommissioning activities. In general, the decommissioning process begins with the assessment stage, followed by planning and management, and lastly the actual decommissioning execution. The best practice approach for responsible decommissioning is to conduct a best practicable environmental option (BPEO) study, which is also known as a comparative assessment and/or decommissioning options assessment. The BPEO will identify the most beneficial or least damaging option to be selected for each decommissioning project by accounting for all relevant influencing aspects such as technical, environmental and social impacts, costs, stakeholder opinions, legal compliance as well as health and safety. Such documentation is important to demonstrate that potential impacts arising from decommissioning activities have either been removed or are reduced to as low as reasonably practicable (ALARP). The best decommissioning option will vary depending on local aspects such as environmental baseline conditions, key stakeholders, waste management and disposal facilities, available technologies and the viability of all options considered including reuse (e.g. rigs to reef). This paper outlines recommended approaches for successful decommissioning planning, highlighting key environmental considerations and other important influencing factors. The aim is to demonstrate the importance of holistic thinking for the development of decommissioning strategies to establish a robust decommissioning plan and successful execution.

The dense urban development on a hilly terrain, together with intense seasonal rainfall, gives rise to acute slope safety problems in Hong Kong. This is reflected by a death toll of over 470 fatalities due to landslides since the 1940s. Site formation works form an integral part of infrastructure and building development in a steeply sloping terrain. In the mid-1970s, the Hong Kong government embarked on a slope retrofitting programme, known as the landslip preventive measures programme, systematically to reduce landslide risk by upgrading substandard man-made slopes to modern safety standards. By 2010, some 4500 high-risk government man-made slopes had been upgraded through the implementation of engineering works. In 2010, the government launched the landslip prevention and mitigation programme to dovetail with the completion of the previous programme. The new rolling programme aims to contain the overall landslide risk to an ‘as low as reasonably practicable’ level by upgrading the remaining substandard man-made slopes and systematically mitigating the landslide risk posed by vulnerable natural terrain catchments. In this paper, the advances and innovations arising from this unique systematic slope safety programme are described.

In the last 10 years biogas production tripled, resulting in an increasing number of related facilities. The present study addresses safety issues of such activity on the basis of past accident analysis. A database of accidents related to biogas supply chain was created and data on 169 accidents were collected from different literature sources. Trends, causes of accidents, scenarios, and consequences were analysed also using Multi Correspondence Analysis to obtain correlations between causes of accidents and scenarios. The study showed that almost 12% of the past accident analysed can be classified as major accidents. The number of accidents is growing faster than biogas production. A risk assessment was carried, based on the analysis of accident frequencies and consequences. A non-negligible risk profile, typical of ALARP zone, was obtained for this industrial sector, revealing an emerging risk issue. The main lessons learnt are the need of developing and adopting specific safety standards and of improving the safety culture and risk awareness in the biogas production sector.

Safety legislation and standards in the UK and elsewhere require risks to be reduced ‘as low as reasonably practicable’ (ALARP). Case law defines ALARP as a level of safety that could not be reduce...

The HAZOP and LOPA methods are commonly used for qualitative hazard identification and semi-quantitative assessment of risk in the process industries. Integration of HAZOP and LOPA techniques into a single study has provided the practical advantage of utilizing the same team of subject matter experts to complete evaluation of hazard scenarios, identify needs for further risk reduction, recommend specific safeguards required and confirm resulting residual risk is acceptable. While practical and efficient, the one-step comprehensive integrated HAZOP/LOPA method can have pitfalls. In particular, use of LOPA alone to confirm risk acceptability can lead to complex solutions to meet order-of-magnitude threshold requirements for risk reduction and restrictive requirements for independent protection layers (IPLs). Quantitative methods are sometimes required beyond HAZOP/LOPA to obtain a more precise evaluation of identified hazards and benefits of the associated safeguards. This article presents a risk assessment approach incorporating advanced analysis, including human factors task, fault tree and cost-benefit analysis, following HAZOP/LOPA analysis. To illustrate this approach, an example is shown on the selection of appropriate engineering design options for cyclic regeneration of dense phase ethylene treaters, which have unique safety concerns. Using advanced analysis, a cost effective design solution is developed and is shown to reduce risk to as low as reasonably practicable (ALARP). © 2016 American Institute of Chemical Engineers Process Saf Prog 36: 192–201, 2017

Using the concept of ALARP (As Low As Reasonably Practicable) and the Expected Utility Theory (EUT), this paper introduces a risk-based optimisation approach to the SIL (Safety Integrity Level) determination process. In the commonly used SIL determination methods the target SIL is determined by comparing the existing level of risk to a pre-set corporate risk target; the gap defines the level of risk that should be reduced by additional layers of protection, such as safety systems. Such methods do not directly factor in the cost impact of the allocated target SILs, nor do they examine the practicability of all SIL alternatives in reducing the risk to as low as possible. The method presented in this paper is based on assigning utility values to different SIL alternatives, in accordance with the cost and benefits of each alternative, and comparing the expected utility values in order to determine the optimum SIL rating as target. A numerical analysis has been developed and applied to the SIL evaluation for a gas turbine over-speed protection to demonstrate the advantages and challenges of the new method.