As Low As Reasonably Practicable Research Articles

Safety considerations for hydrometallurgical metal recovery from lithium‐ion batteries

AbstractThis paper presents a comprehensive overview of the critical process safety considerations inherent in hydrometallurgical metal recovery within the lithium‐ion battery (LiB) recycling process. As hydrometallurgy application in LiB recycling is still in the early stages of development, it is crucial to identify the hazards and provide safety recommendations. Hazards related to hydrometallurgy are identified and categorized in process, toxic, fire, explosion, corrosion, environment, storage, and transport hazards. Risk reduction measures are suggested using the hierarchy of control methodology to eliminate and reduce risks to as low as reasonably practicable (ALARP), based on UK regulatory framework.

A sequential three-way risk sorting model with the cautionary principle under probabilistic linguistic environment

Risk assessment plays a crucial role in managing risks associated with systems, products and services. In practical risk assessment, the cautionary principle is widely adopted by individuals to prevent accidents, and the degree of caution varies with the risk level of potential hazardous activities (PHAs). Therefore, it is necessary to explore a sequential risk assessment model integrating the cautionary principle. To this end, we design an improved risk assessment model based on sequential three-way decision (STWD) model and cautionary principle. Firstly, a risk distance measure under probabilistic linguistic environment is proposed to effectively reflect varying degrees of caution when individuals analyzed PHAs of different risk levels. Then, a comprehensive risk weight optimization model is constructed on the consideration of the importance ranking and correlations of risk attributes. Subsequently, STWD and the as low as reasonably practicable (ALARP) principle are integrated to build the risk sorting model, and both the risk prioritization and classification of PHAs are obtained from the sequential risk sorting process. Finally, we verify the reliability of our proposed model through an example of a floating offshore wind turbine system. The findings validate the crucial role of cautionary principle in risk assessment.

Multi-objective optimization of structural fire design

Probabilistic risk assessment can be used for determining a design with a residual risk that is As Low As Reasonably Practicable (ALARP). Existing risk-based design approaches however predominantly focus on single objectives, which can be impractical considering the need for structures to meet diverse performance criteria across various dimensions, including monetary costs, environmental costs, and structural performance measures. To address these challenges, this study proposes the use of a multi-objective optimization (MOO) approach within a risk-based framework. Within the MOO framework, design goals for sustainability and resilience are incorporated together with safety objectives. The MOO approach is developed here for the risk-based design of structures exposed to fire. A multi-objective problem is formulated for a reinforced concrete slab in a multi-family dwelling by identifying design parameters, objectives, and constraints. Taking environmental costs into account has little effect on the optimum design obtained through MOO for the case study, except in cases where CO2 emissions are highly valued. A limited increase in investment is observed to render the structure repairable after a fire incident, highlighting the importance of factoring in post-fire reparability in structural fire design.

As low as reasonably practicable (ALARP): a moral model for clinical risk management in the setting of technology dependence.

Children dependent on life-prolonging medical technology are often subject to a constant background risk of sudden death or catastrophic complications. Such children can be cared for in hospital, in an intensive care environment with highly trained nurses and doctors able to deliver specialised, life-saving care immediately. However, remaining in hospital, when life expectancy is limited, can considered to be a harm in of itself. Discharge home offers the possibility for an improved quality of life for the child and their family but comes with significant medical risks.When making decisions for children, two ethical models predominate, the promotion of the child's best interests or the avoidance of harm. However, in some circumstances, particularly for children with life-limiting and/or life-threatening illness, all options may be associated with risk. There are no good options, only potentially harmful choices.In this paper, we explore decisions made by one family in such circumstances. We describe a model adopted from risk management programmes beyond medicine, which offers a potential framework for identifying risks to the child that are morally permissible. Some risks and harms to a child, not ordinarily permitted, may be acceptable when undertaken in the pursuit of a specified desired good, so long as they are as low as reasonably practicable.

Risk Assessment of Liquid Ammonia Loading Process at Petrochemical Company Docks

This study addresses a risk assessment at terminal facility of petrochemical company. Hazards are identified using HAZOP (hazard and operability) while the frequency of hazard is conducted by means of fault tree and event tree analysis. The consequence of hazards is analyzed using process hazard analysis tools and risk is represented in F-N curve according to Hongkong Government Risk Guidelines (HKRG). Five leak diameter scenarios were examined resulting that two hazards are potentially occur during the ammonia loading process such as gas dispersion and explosion. According to the result of frequency and consequence analysis, those hazards is laid in ALARP (as low as reasonably practicable) region, hence there is no mitigation necessarily to be taken. However, for the safe operation, the company should ensure that the risks will not move to unacceptable region by performing routine maintenance and all safety procedures established by the company were well implemented.

Design criteria for upstream raised tailings storage facilities

For more than 100 years upstreaming has been the dominant raising method for tailings storage facilities in Southern Africa. However, there is a growing view worldwide that upstreaming is inherently less safe than centreline or downstream raising of tailings storage facilities. Considering that more than 90% of the 250 plus operational tailings storing facilities in Southern Africa are upstream raised and cannot economically be converted to, or replaced by, downstream raised facilities, the arguments for and against upstreaming were examined in this study. It was found that no compelling reason exists to ban upstreaming in Southern Africa, provided that failure mechanisms are thoroughly considered to prevent serious design omissions. The ALARP (as low as reasonably practicable) approach is introduced as a practical method to deal with the risk of failure, and its hierarchical application is illustrated.

Feasibility study of 3D gamma imaging for improving radiological protection at Sizewell B nuclear power plant.

Nuclear power plants are continuously looking to optimise their radiological monitoring and visualization techniques. At Sizewell B nuclear power plant in the UK, a trial was carried out to judge the feasibility of a gamma imaging system to provide accurate visual representation and characterisation of source terms on an operational pressurized water reactor. Data was collected through a series of scans taken in two rooms within a radiological controlled area at Sizewell B and used to generate radiation "heat maps". This survey type supports As Low As Reasonably Practicable (ALARP) (UK equivalent to ALARA) working in areas with high general area dose rate by gathering radiometric data and generating intuitive visual characterisation of work area source terms.

Improving process safety for the operation of Major Hazard Facilities

The discipline of process safety management has proven to be a valuable tool for assisting operators of Major Hazard Facilities (MHF) in focussing on the critically important ‘few’, with a heightened level of scrutiny than that of the ‘many’ lesser critical yet still important elements of a process system. This discipline attracts much oversight, discussion, and enthusiasm from many areas within and outside asset operations teams. Major Accident Hazards may vary in severity and probability throughout the life cycle of existing assets, it is, therefore, important to review these periodically. Clear purpose and definition of Safety Critical Elements (SCE), and in some cases Integrity Critical Elements (ICE), along with intelligent rationalisation of these to reflect the items of legitimate criticality, will allow higher precision and clarity, leading to higher confidence and an improved ability to manage genuine process safety risk. Further improvements can be made through real-time and near-time reporting through risk visualisation bowtie diagrams to ensure hazards can be managed to As Low as Reasonably Practicable (ALARP) and their status made visible to enable the most effective prioritisation of work which prioritises restoration of the most compromised threat and consequence barriers first.

An advanced framework for leakage risk assessment of hydrogen refueling stations using interval-valued spherical fuzzy sets (IV-SFS)

The extensive population growth calls for substantial studies on sustainable development in urban areas. Thus, it is vital for cities to be resilient to new situations and adequately manage the changes. Investing in renewable and green energy, including high-tech hydrogen infrastructure, is crucial for sustainable economic progress and for preserving environmental quality. However, implementing new technology needs an effective and efficient risk assessment investigation to minimize the risk to an acceptable level or ALARP (As low as reasonably practicable). The present study proposes an advanced decision-making framework to manage the risk of hydrogen refueling station leakage by adopting the Bow-tie analysis and Interval-Value Spherical Fuzzy Sets to properly deal with the subjectivity of the risk assessment process. The outcomes of the case study illustrate the causality of hydrogen refueling stations' undesired events and enhance the decision-maker's thoughts about risk management under uncertainty. According to the findings, jet fire is a more likely accident in the case of liquid hydrogen leakage. Furthermore, equipment failure has been recognized as the most likely cause of hydrogen leakage. Thus, in order to maintain the reliability of liquid hydrogen refueling stations, it is crucial that decision-makers develop a trustworthy safety management system that integrates a variety of risk mitigation measures including asset management strategies.

Updating threshold for IMO cost-benefit assessment

ABSTRACT The International Maritime Organization rule-making process utilizes a set of guidelines for the so-called Formal Safety Assessment (FSA). This process is based on a risk assessment and its purpose is to ensure that the risk to human health and life and to marine environment is tolerable. A central instrument in the FSA methodology is known as ALARP (As Low As Reasonably Practicable) principle which ensures that the risk is controlled in a rational and cost-effective manner. The FSA Guidelines recommend the use of monetary thresholds for performing the cost evaluation and provide an example of indices for measuring the cost efficiency. For risks involving fatalities, these measures require the use of a monetary threshold derived from the concept of Cost of Averting a Fatality (CAF). Due to the linkage to economic parameters, this threshold needs to be updated regularly to allow for correct cost-benefit assessment in the FSA context.

Application of ALARP cost-benefit analysis to hospital-based radiation protection

The UK Ionising Radiations Regulations 2017 require employers to restrict radiation doses to their employees and the public to be as low as reasonably practicable (ALARP). This article looks at the boundary between what might be considered to be reasonable and unreasonable in protecting staff and the general public in the field of hospital-based diagnostic radiology. Guidance on cost-benefit analysis in support of ALARP has been used to formulate relationships for the estimation of the cost at which a radiation protection intervention is no longer ALARP. These relationships allow for a direct link between a reduction in radiation exposure and the maximum reasonable ALARP cost of intervention. Application of the approach to hospital-based radiation protection situations show that the ALARP cost limits for protecting radiation workers against the residual risks in the hospital environment are relatively low. Conversely, the ALARP limit to investment in public dose reduction by means of reducing patient doses can be very high.

Could posterior-anterior projection cervical spine radiographs improve image quality and dose reduction

Introduction: Anterior-posterior (AP) cervical spine X-rays are routine examinations to assess degenerative change, persistent pain and traumatic injuries. Multiple radiosensitive organs lie anteriorly within this anatomical region, increasing the stochastic risk of cancer. If a posterior-anterior (PA) projection was utilised, the radiation dose could potentially be reduced. The hypothesis of this study is to evaluate the change in radiation dose and image quality between AP and PA positions. Materials and methods: An anthropomorphic phantom was positioned AP erect against a digital radiography (DR) detector with 30 thermoluminescent dosimeters (TLDs) inserted to record the thyroid, breast, ovaries, and testes absorbed radiation dose at an exposure of 66 kV and 8 mAs. The phantom was repositioned PA erect and repeated. Images were assessed against an image quality criteria Likert scale by qualified radiographers. The mean and standard deviations were calculated for dose and image quality and compared using a t-test and Wilcoxon Signed Ranks Test. Results: The PA erect cervical spine reduced radiation dose to the right thyroid by 92% (44.7 µGy; p=0.00) and the left thyroid by 89% (43.7 µGy; p=0.00), with further reductions in scatter dose to the breasts (0.35-0.45 µGy; p=0.85), ovaries (0.41 µGy; p=0.57), and testes (0.04 µGy; p=0.98). Image quality scores for the end plates, pedicles, joint spaces, spinous and transverse processes, cortical and trabecular bone patterns, and soft tissues were near equivalent (p=0.32). Conclusion: Data analysis suggests that PA cervical spine positioning for X-rays in the laboratory adheres to as low as reasonably practicable (ALARP) guidance on X-ray examinations to reduce radiation dose to male and female internal organs (thyroid, breast, ovaries) without a reduction in image quality compared to AP positioning. Further research in clinical practice is advised.

A new approach for quantitative risk assessment of gas explosions on FPSO

Gas explosions on floating, production, storage and off-loading units (FPSO) cause catastrophic consequences. It is vital to perform an accurate risk assessment for preventing these hazards. This paper presents a comprehensive quantitative risk assessment approach for evaluating the whole gas explosion process from initial leakage to final explosion. A stochastic sampling method is proposed to determine the explosion scenarios by using historical statistics data. Secondly three operational barriers: gas detection, emergency shutdown and ignition prevention are arranged to prevent the development from leakage to explosion. The sequential Bayesian Network (BN) predictive model is constructed to describe the hazard development by considering Human and organizational factors (HOFs). As low as reasonably practicable (ALARP) principle is performed to assess the explosion risks. The proposed approach has been applied to a case study focusing on estimating the risk levels for humans and constructions. It turns out that HOFs have significant effect on the normal functions for operational barriers, if ignoring the HOFs effect the accident risks will be underestimated. This approach is especially good at updating the results whenever new data becomes available. Several safety measures can be recommended based on the diagnostic analysis of BN.

A Review on Residual Solid Propellant Disposal Methods Using HRIM, RISK Score Matrix, Safety Consequence Analysis and Environmental Impact Analysis

Introduction: Solid propellants are high energetic materials used for Launch vehicles and military applications. During solid propellant processing residual propellant generates due to less pot life, machining for insulation lining, scaled and sub scaled trials for mechanical and ballistic properties prediction. A conventional method for disposal of residual propellant is open-air burning; other alternate methods in the literature are incineration, wet air oxidation and molten salt destruction. Methods: Hazard assessment is carried out for the disposal methods both conventional and alternate. Preliminary hazard analysis (PHA), Hazard Risk Index Matrix (HRIM), Risk Score Matrix and as low as reasonably practicable (ALARP) are used to assess the Hazard. Results: Based on the study and calculations Open air burning is having less risk score and medium level safety risk acceptance and tolerable risk which can mitigate. Open-air burning is the safest, efficient and cost-effective way to dispose of the high energetic material but the disadvantage of this method is environmental pollution, high temperature and toxic gases exposure to fire personnel. Based on safety consequences analysis, the 1 gram of solid propellant is found to be 1.308 grams of Trinitrotoluene (TNT) equivalency, and one-time open burning creates 3.822 KPa overpressure on the atmosphere where minimum overpressure to create damage effect is 5 KPa. Conclusion: The environmental impact analysis for disposing of solid propellant gives information about different pollutants, their concentrations in the atmosphere at different altitudes and their impact. Solid propellants are hazard reactive materials they were the one exception under the Resource Conservation and Recovery Act (RCRA) that controls the destruction of hazardous waste.

Concurrent 23. Presentation for: Safety zones and decommissioning

Presented on Thursday 19 May: Session 23 Australia’s oil and gas sector expects approximately 56 billion (AUD) to be expended for decommissioning costs over the next 50 years. The view of the National Offshore Petroleum Safety and Environmental Management Authority is that the designated decommissioning approach must provide equal or better environmental outcomes when compared to full removal of the infrastructure (considered the ‘best case’ expectation under current legislation) and meets as low as reasonably practicable (ALARP) levels of risk. Decommissioning alternatives are generally evaluated through a comparative multicriteria assessment approach, for example, a net environmental benefit analysis-based comparative assessment (NEBA-CA). Decommissioning options cover a range of possibilities, from full removal to leaving subsea structure in situ (in part or in whole). NEBA-CAs we have conducted suggest that some subsea structures are projected to generate significant ecological and social value over multiple generations to come. Thus, in these cases, management in situ can provide greater benefits to the public when compared to full removal. During operation, oil and gas assets typically incorporate a safety zone. If subsea structure is selected to be managed in situ, a question that arises is, should the safety zone be maintained or removed? Our experience indicates that if the safety zone is removed after decommissioning an asset that is left in situ, there may likely be a greater adverse impact on ecological and social values, depending upon the asset location. This abstract showcases the value of the use of safety zones to maximise environmental value while managing risk. To access the presentation click the link on the right. To read the full paper click here

Safety zones and decommissioning

Australia’s oil and gas sector expects approximately 56 billion (AUD) to be expended for decommissioning costs over the next 50 years. The view of the National Offshore Petroleum Safety and Environmental Management Authority is that the designated decommissioning approach must provide equal or better environmental outcomes when compared to full removal of the infrastructure (considered the ‘best case’ expectation under current legislation) and meets as low as reasonably practicable (ALARP) levels of risk. Decommissioning alternatives are generally evaluated through a comparative multicriteria assessment approach, for example, a net environmental benefit analysis-based comparative assessment (NEBA-CA). Decommissioning options cover a range of possibilities, from full removal to leaving subsea structure in situ (in part or in whole). NEBA-CAs we have conducted suggest that some subsea structures are projected to generate significant ecological and social value over multiple generations to come. Thus, in these cases, management in situ can provide greater benefits to the public when compared to full removal. During operation, oil and gas assets typically incorporate a safety zone. If subsea structure is selected to be managed in situ, a question that arises is, should the safety zone be maintained or removed? Our experience indicates that if the safety zone is removed after decommissioning an asset that is left in situ, there may likely be a greater adverse impact on ecological and social values, depending upon the asset location. This abstract showcases the value of the use of safety zones to maximise environmental value while managing risk.

Contribution to developing a new environmental risk management methodology for industrial sites

A fundamental requirement of any environmental management system for industrial sites is the identification and assessment of risk. To meet international standards in terms of environmental protection and preservation, industrial sites should ensure that a comprehensive environmental risk management process is in place by systematically identifying and managing risks arising from internal and external factors. The purpose of this study was to develop a new methodology to determine the significance of environmental hazardous situations associated with a process or activity. It uses qualitative or quantitative techniques to pinpoint weaknesses in design, operation, and lines of defense provided by engineering and administrative controls, which can lead to an environmentally hazardous event. It may also provide an assessment of risk resulting from the magnitude of the consequence and the probability of the environmental event occurring. The fundamental principle of this new risk-based hazard methodology is that whilst risk cannot be eliminated, it should be possible to reduce to ALARP (as low as reasonably practicable), and the environmental risk matrix could be a useful tool for establishing if an environmental risk rating is tolerable or not based on the likelihood and consequences. The outcome of this study is developing a new environmental risk matrix based on different consequences (health, environmental, reputation, and business interruption) with likelihood criteria. This matrix could be applied by industrial sites to identify and control their environmental risks.

Individual risk evaluation for landslides: key details.

Risk-taking is an essential part of life. As individuals, we evaluate risks intuitively and often subconsciously by comparing the perceived risks with expected benefits. We do this so commonly that it passes unnoticed, like when we decide to speed home from work or go for a swim. The comparison changes, however, when one entity (such as a government) imposes a risk evaluation on another person. For example, in a quantitative risk management framework, the estimated risk is compared with a tolerable risk threshold to decide if the person is ‘safe enough’. Landslide risk management methods are well established and there is consensus on tolerable life-loss risk thresholds. However, beneath this consensus lie several key details that are explored by this article, along with suggestions for refinement. Specifically, we suggest using the risk unit, micromort (one micromort equals a life loss risk of 1 in 1 million), in describing risk estimates and thresholds, to improve risk communication. For risk estimation, we provide guidance for defining and combining landslide scenarios and for recognizing where unquantified risk from low-probability/high-consequence scenarios ought to inform risk management decisions. For risk tolerance thresholds, we highlight the pitfalls of selecting unachievably low thresholds and suggest that there is no single universal threshold. Additionally, we argue that gross disproportion between costs and benefits of further risk reduction, which is integral to the As Low As Reasonably Practicable (ALARP) principle, is a commonly unachievable and counter-productive condition for risk tolerance, and other conditions centered on proportionality often apply. Finally, we provide several figures that can be used as risk communication tools, to provide context for risk estimates and risk tolerance thresholds when these values are reported to decision makers and the public.

Safety and risk analysis at railway crossings of north-south Addis Ababa light rail

Purpose Railway-level crossings (RLCs) are the point of intersection between rail and road users and are therefore hotpots of road-rail user conflict and catastrophic collisions. The purpose of this study is to assess the risks associated with RLCs and suggest probable reduction measures. Through questionnaires and visual inspection, the authors identify the safety risks, hazards and hazardous events at some railway crossing of Addis Ababa light rail transit (AA-LRT) north-south (N-S) route. The identified risky events are then categorized based on As Low As Reasonably Practicable (ALARP) principle and generic risk ranking matrix. The authors then examine existing safety management measures at railway crossing and assess the need for additional safety management. Five major crossings on the 16.9 km (10.5 mi) N-S line, starting from Menelik II Square to Kality, were considered for the study. This study is carried out by data collection from about 145 stakeholders and the application of statistical data and risk analysis methods. The major findings of this study and the recommendations for improvement are suggested. Design/methodology/approach The research followed a case study approach. Through questionnaires and visual inspection, the authors identify the safety risks, hazards and hazardous events at some railway crossing of AA-LRT N-S route. The identified risky events are then categorized based on ALARP principle and generic risk ranking matrix. Collected data was then analyzed using SPSS to deduce relationships. Findings The study findings reveal human factors as the greatest cause of accidents, injury or death. About 22% of hazards identified by category are human factors, whereas 20% are because of technical problems. Intolerable risks stand at 42%, whereas the tolerable risks are at 36% according to risk classification results as per the ALARP model. Because the process of risk management is a long-term cycle, its importance should not be missed at any time. Research limitations/implications Because of design considerations of RLCs and the difference in generalized human behaviors for people of a given region, the results are limited to AA-LRT RLCs. This study opens a discourse for detailed evaluations, qualitative and quantitative analysis into the categorized identified hazards. There is also room for additional research into the performance of RLCs aimed at formulating standard necessary features that should be included on RLCs for proper risk control especially in emerging economies. Originality/value The research paper is original and has not been submitted for consideration to other journals.

ALARP Criteria to Estimate Acceptability and Tolerability Thresholds of the Investment Risk

Assessing the riskiness of investments in civil works is an integral part of the decision-making process. The main limitation is the absence, both in the regulatory landscape and in the literature of the sector, of threshold values that can guide the analyst in expressing an assessment on the acceptance of the investment risk. The aim of the paper is to define a risk management model that overcomes this gap by introducing acceptability and tolerability thresholds for project risk. The idea is to jointly use: (i) the As Low As Reasonably Practicable (ALARP) logic, from which the concepts threshold of acceptability and tolerability of risk derive, for the first time applied to assess the project risk in the civil field; (ii) the Capital Asset Pricing Model (CAPM) and statistical methods to define an innovative methodology for estimating the aforementioned threshold values. According to the proposed approach, these risk limit values can be specified according to both the investment sector and the socio-economic context of the project. The implementation of the methodology in the civil company sector in Europe allows to validate the described model. The elaborations show that the financial performance of the project is widely acceptable if the Expected Internal Rate of Return is greater than 7.8%; unacceptable if the expected rate of return is less than 5.6%; and tolerable as an ALARP if the expected rate is between 5.6% and 7.8%. The estimated acceptability and tolerability thresholds can provide the economic operator with a more immediate and consistent evaluation of the triangular balance of risks, costs, and benefits. This allows the decision-making process to become more rational and transparent.