Quantitative Safety Assessment Research Articles

Quantitative Assessment of Safety and Health Risks in HAZMAT Road Transport Using a Hybrid Approach: A Case Study in Tehran

Given the catastrophic consequences of hazardous materials’ leakage from trucks, it has become necessary to adopt a coherent approach for quantitative risk assessment in this process. Therefore, th...

Predictive Formulation for the Ultimate Combinations of Axial Force and Bending Moment Attainable by Steel Members

This paper is devoted to quantitative safety assessment of steel beam-columns, and delivers a plain analytical formulation for predicting the ultimate combinations of axial force and bending moment, allowing for material and geometric non-linearities. The formulation easily permits the ultimate interaction diagram of a steel member to be accurately constructed, as well as the structure to be checked for combined axial force and lateral load. It applies specifically to columns but can be used for any members. The formulation is also configured as a tool for straightforward design and construction. To that end, the structure is converted from an imperfect geometrically non-linear system into a geometrically linear system without imperfections, which allows the structure to be designed and dimensioned referring to the first order moments. The paper gives a detailed account of the mathematical developments and the final expressions, including some illustrative examples.

МEТОДИЧНІ ПIДХОДИ ДО ОЦІНКИ ПРОЦЕСІВ МОДЕРНІЗАЦІЇ СИСТЕМИ EКOЛOГOБEЗПEЧНOГO CТAЛOГO POЗВИТКУ

The article presents the analysis of the features of the modernization of regions, using existing methods. It is determined that a feature of the existing methodological approaches is the presence of a large number of indicators and the need for expert assessments, which significantly complicates the study. A new approach to the problem of studying the environmental safety of territories has been identified based on the ecological paradigm. The advantage of the new approach, as opposed to the old, conventional one, which relies on the “pollution-resource” paradigm, is that a comprehensive assessment of the level of environmental security is proposed on the basis of a new organizational structure of environmental control and information model, by attracting specially formed new indicators. environmental status - indicators and quality indices. An integral part of this is the level of environmental modernization, which is closely linked to environmental risk and allows for a quantitative assessment of environmental safety. Development of methodological approaches to the assessment of environmental modernization from the standpoint of environmental and technogenic safety was based on indicators in three areas: protection of atmospheric air and water resources, as well as waste management. Their comprehensive assessment will help to determine the level of population load, territories, threats and risks, provided that there is a continuing trend of significant negative impact of the impacting factors. It is established that the regions of Ukraine as the object of study can be considered in the form of a multilevel dynamic system of large dimension with complex relationships both within individual levels and between levels in general. As components of this system, various objects of protection are further analyzed: existing population, GRP, environmental elements, investments, etc. Given these provisions, the level of modernization can be estimated. The development of an integral index, in our opinion, makes it possible to assess as much as possible interregional differences in the level of danger, using a certain number of indicators for this purpose. It also deepens the understanding of the object of study and its patterns: instead of the isolated properties of the individual sides of the object, we obtain a holistic characteristic, which guarantees its ultimate advantage. As a result of the research, a general scheme of environmental modernization assessment was formed.

Embedding aircraft system modeling to ATM safety assessment techniques: The runway excursion safety case for runway strips with reduced strength

Several concepts were developed over the last years to fit safety assessment (SA) techniques to ATM operational needs. Quantitative SA models proved to achieve robust results if reliable data for hazard modeling and corresponding target levels of safety are available, inducing much effort in historic incident data gathering. Meanwhile, we consider hazard probability determination as a reliable mathematical process whereas consequence modeling as second risk component remains mainly a subjective technique. This paper presents an analytic approach to link a mechanical model of a representative critical aircraft part called TSIM (Tire-Soil Interaction Model) to an FEM (Finite Element Method) tire stress simulation to study critical aircraft part failures (here the landing gear) at high detail level during a hazardous condition. In doing so, we can show to significantly and robustly increase the transparency for allocating a severity category to a given hazard compared to current categories based on EASA and other international standards. The research also shows that risk-based aircraft part certification reveals weaknesses in data and setting of target levels of safety (TLS) as a risk considered to be acceptable in non-nominal situations. We apply the developed concept to a runway excursion scenario where the infrastructure is considered non-compliant to EASA/ICAO regulations.

Electrical Safety Considerations in Large-Scale Electric Vehicle Charging Stations

Several safety regulations, particularly concerning the charging of electric vehicles (EVs) are developed to ensure electric safety and prevent hazardous accidents, in which safety requirements for the EV supply equipment (EVSE) and the EV battery are two main driving factors. At present, quantitative assessment of electrical safety considering the operation conditions of large-scale EV charging stations (EVCSs) has still remained a challenge. Driven by the hierarchy of hazard control mechanisms, this article proposes a holistic approach to evaluate the electrical safety of the large-scale EVCSs when coupled to renewable power generation. Our approach mainly focuses on several topics on the operational safety of EVCS primarily concerning: 1) the facility degradation which could potentially result in a compromised EVSE reliability performance and EVCS protection failure; 2) the cyberattack challenges when the smart charging and the communication between EVCSs and electric utilities are enabled; and 3) the potential mismatch between the renewable output and EVCS demand, which could trigger the system stability challenges during normal operation and inability to supply the critical EV loads during outages. The proposed framework will provide informative guidelines to the EVCS operators for continuous monitoring and effective management of the day-to-day EVCS operation.

Об объективной количественной оценке безопасности труда

The problem of ensuring occupational safety in the modern world is considered. It is related to the fact that the applied principle of hygienic rating, which is based on the determination of the limit values of each of production processes factors that have a harmful effect on the human body, does not ensure occupational safety. The main reason for this situation is the identification of the level of hazard using different systems of points and classes that are not metrologically justified. In addition, a person is always simultaneously exposed to the large number of factors, and it is almost impossible to consider all of them. One of the solutions to the problem is the application of risk theories. However, this approach does not provide for identifying the process regularity occurring in the human body under the influence of harmful factors, which does not allow to find the effective ways for occupational safety improvement. To identify criteria for an objective quantitative assessment of occupational safety, the studies were carried out concerning the functioning of the human body as a nonequilibrium thermodynamic system. It obeys the law of the masses and the laws of thermodynamics of the biological systems for cases of physical labor in the malposition, heavy physical labor and stress psychological labor. The research results showed that as a quantitative criterion for the hazard of labor, the time can be used of restoration of functional shifts caused by the influence of production factors, after their removal, during rest. Daily and weekly labor hazard factors are proposed. They characterize the level of functional shifts restoration during rest between the working shifts and for the weekend between working weeks. Labor is considered safe if these factors are less than one.

Fatigue Failure of runway beams due to wheel loads

ABSTRACTThe introduction of the Eurocode 3 led to a significantly stricter fatigue classification, especially for flange to web connections of runway beams of heavy duty cranes compared to former national design rules like DIN 4132. At present, this leads to a doubling of the cross‐sectional thicknesses, which e.g. can result into web plates with extreme thicknesses of 80 mm. Execution as well as monitoring of such flange to web connections using full penetration tee‐butt welds are quite critical and thus no longer to be realized reasonably.On this account new fatigue strengths for the runway beam specific fatigue detail “Top flange to web junction of runway beams” in EC3‐1‐9 Table 8.10 have been established within the FOSTA‐research project “Fatigue failure of runway beams due to wheel loads in heavy smeltery cranes” as recommendations for an eventually modification or even extension of the current codes. In Particular, the detail executed using full penetration tee‐butt welds has been investigated in the framework of this research project.The essential core of the methodical approach is that real existing crane runway girders have been examined, documented and evaluated in regard of fatigue failure of the flange to web connection. In this way, a direct quantitative assessment of safety against fatigue failure for the investigated detail could be derived. In addition, synthetic notch cases have been investigated numerically. The results of both methodologies have been prepared for a proposal of amendment of the current codes. This paper provides an insight into the methodological approaches and the main results achieved.

Lateral load-carrying capacity of steel columns with fixed-roller end supports

The subject matter of this paper is the interaction of flexure and compression in steel beam-columns with fixed-roller boundary conditions. It is shown that, for those end restraints, the effective length factor approach is inaccurate to account for geometric non-linearity.The paper then presents a formula to predict the strength of steel members subjected to simultaneous axial compression and transverse load, allowing for the formation of plastic hinges one following the other with a considerable gap. The formula is devoted to quantitative safety assessment, as it is more accurate than conventional formulas, and also to the design phase, as it is simple to use.The paper gives a detailed account of the formulation and provides some examples that show differences from the results obtained from conventional and code formulas.

Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment

Introduction: The mining and tunneling industries are historically associated with hazardous exposures that result in significant occupational health concerns. Occupational respiratory exposures causing pneumoconiosis and silicosis are of great concern, silicosis being non-curable. This work demonstrates that compressed-air workers (CAWs) performing tunnel hyperbaric interventions (HIs) may be at risk for hazards related to bentonite exposure, increasing the likelihood of developing harmful illnesses including cancer. Bentonite dust inhalation may result in respiratory levels of silica exceeding acceptable industrial hygiene standards. Methods: A qualitative observational exposure assessment was conducted on CAWs while they were performing their HI duties. This was followed by quantitative data collection using personal and area air sample techniques. The results were analyzed and interpreted using standard industrial hygiene principles and guidelines from NIOSH and OSHA. Results: Our work suggests bentonite dust exposure may be an emerging particulate matter concern among CAWs in the tunneling industry. Aerosolized bentonite particles may have potential deleterious effects that include pneumoconiosis and silicosis. Silicosis can result in the development of pulmonary carcinoma. Conclusions: The modern tunneling industry and required hyperbaric interventional tasks represent a potential public health and occupational concern for CAWs. This paper introduces the modern tunneling industry and the duties of CAWs, the hazardous environment in which they perform their duties, and describes the risks and potential harmful health effects associated with these hazardous exposures.

An Approach for Development of Local Safety Performance Functions for Multi-Lane Rural Divided Highways in Egypt

Egypt is a middle-income country, belonging to the Eastern Mediterranean Region (EMR). Egypt used to be the worst performing EMR country, with over 45 fatalities per 100,000 population. It is considered an example case of many EMR countries in the region where there is a need for quantitative assessment of safety on its roads. The Highway Safety Manual (HSM) offers several functions to calculate safety performance (SPFs), which can estimate crash frequency on a highway network according to its geometric and traffic characteristics. The HSM was developed in the United States using road and crash data specific to its environment. Jurisdictions and other non-U.S. regions were encouraged to develop locally derived models suitable for the local characteristics of roads and crashes. The objective of this paper is to assess the suitability of using the HSM models on rural multi-lane divided highways in Egypt. The calibrated SPFs considering Egyptian road factors were compared with the actual crash events. The results showed that there was a need to develop locally derived SFPs using negative binomial models. The modeling approach and a validation procedure were presented and are applicable when developing local SPFs to compare how well the model performs to the actual data, and to HSM calibrated models. The models were created using 90% of the data and tested on the remaining 10% of the data. The study found that the results relating to driver behavior would help designers in regions other than the United States to benefit from the HSM.

Qualitative and Quantitative Risk Analysis and Safety Assessment of Unmanned Aerial Vehicles Missions Over the Internet

In the last few years, unmanned aerial vehicles (UAVs) are making a revolution as an emerging technology with many different applications in the military, civilian, and commercial fields. The advent of autonomous drones has initiated serious challenges, including how to maintain their safe operation during their missions. The safe operation of UAVs remains an open and sensitive issue since any unexpected behavior of the drone or any hazard would lead to potential risks that might be very severe. The motivation behind this work is to propose a methodology for the safety assurance of drones over the Internet (Internet of drones (IoD)). Two approaches will be used in performing the safety analysis: (1) a qualitative safety analysis approach and (2) a quantitative safety analysis approach. The first approach uses the international safety standards, namely, ISO 12100 and ISO 13849 to assess the safety of drone’s missions by focusing on qualitative assessment techniques. The methodology starts with hazard identification, risk assessment, risk mitigation, and finally draws the safety recommendations associated with a drone delivery use case. The second approach presents a method for the quantitative safety assessment using Bayesian networks (BN) for probabilistic modeling. BN utilizes the information provided by the first approach to model the safety risks related to UAVs’ flights. An illustrative UAV crash scenario is presented as a case study, followed by scenario analysis, to demonstrate the applicability of the proposed approach. These two analyses, qualitative and quantitative, enable all involved stakeholders to detect, explore, and address the risks of UAV flights, which will help the industry to better manage the safety concerns of UAVs.

Summary of the 2nd International Workshop on Environmental, Safety and Economic Aspects of Fusion Power

The 2nd International Workshop on Environmental, Safety and Economic Aspects of Fusion Power (ESEFP) was held on 23 September 2017 in Kyoto, Japan. The workshop was initiated by the International Energy Agency Technology Collaboration Program on ESEFP. The workshop was well attended with approximately forty participants representing fifteen institutions in eight countries. The presentations covered safety issues and environmental impacts, availability improvement and risk control and socio-economic aspects of fusion power. Quantitative safety assessment of fusion reactors was discussed in depth with the consensus output presented as a plenary presentation at the 13th International Symposium on Fusion Nuclear Technology (ISFNT-13). The next workshop is planned to be held in conjunction with the ISFNT-14 in 2019.

A numerical simulation method for transient behavior of damaged ships associated with flooding

In order to secure the survivability of damaged ships in flooding situations, time-domain simulation is necessary for the quantitative safety assessment, which can predict ship's transient behavior associated with flooding. A numerical simulation method for damaged ships, solving equations of motion with hydrodynamic forces estimated by the semi-implicit MPS (Moving Particle Simulation) for damaged parts and by the potential flow theory for intact parts, has been proposed by the authors (Hashimoto et al., 2013). The validity of the proposed method was demonstrated through comparisons with model experiments in 2-D flooding situations. However it is difficult to apply this simulation method directly to realistic flooding situations because number of particles increases tremendously in 3-D MPS simulation. In this research, the semi-implicit MPS is replaced with the explicit MPS to reduce the CPU cost. In addition, GPGPU (General Purpose computing on Graphics Processing Units) technology is introduced to accelerate the MPS simulation, in which parallel computing runs on GPUs instead of CPUs, so that sufficient number of particles can be used to perform complicated 3-D flooding simulations. In order to validate the developed simulation method, dedicated model experiments are newly conducted. One is a forced roll test for a flooded car-deck compartment and the other is a ship flooding test using a PCTC (Pure Car and Truck Carrier) model. Through comparisons between the model experiment and the numerical simulation, it is well demonstrated that the explicit MPS has good ability to simulate complicated floodwater flows in the car-deck compartment and the developed simulation method can well reproduce ship's transient behavior associated with water flooding.

有人ロケットの安全性評価( 飛行士との,飛行士による,飛行士のための宇宙船の安全制御 第9回)

有人ロケットの安全性評価( 飛行士との,飛行士による,飛行士のための宇宙船の安全制御 第9回)

The Research Framework for Quantitative Safety Assessment for Safety-Critical Computer Systems

Objectives: A safety-critical computer system has to be designed with safety in mind. The purpose of this paper is to identify and assess the safety hazards by using the proposed framework for Safety-Critical Computer Systems (SCCS). Methods/Statistical Analysis: Computer software quality models like McCall’s and Boehm’s were deficient in addressing the basic safety issues of SCCS. This paper proposes another safety model for software safety by adjusting McCall’s product quality model that particularly distinguishes the conditions comparing to software safety in safety-critical applications. The conditions in the proposed software safety model relate to Hazard Analysis distinguishing of Completeness of safety requirements, Safety-critical Design, Coding, and Testing. Findings: The criteria in the proposed software safety model relate to Hazard Analysis (HA) distinguishing of safety requirements, Completeness of safety requirements, Safety-critical Design, Safety-critical Coding, and Safety-critical Testing. The proposed safety model changes the current quality model by presenting different safety criteria’s and metrics in all phases of Software life cycle to assess the software safety. This model was connected to a safety basic Railroad Crossing Control System (RCCS) which is a laboratory prototype and obtained better results in terms of safety. Application/Improvements: This model was connected to a safety basic Railroad Crossing Control System (RCCS) which is a laboratory prototype and obtained better results in terms of safety.

Chemical-technological and mineralogical-geochemical aspects of the radioactive waste management

This paper considers various matrices that are able to incorporate components of radioactive wastes (RAW) of different origin. It is noted that attempts to develop the single phase crystalline matrix to immobilize all RAW components failed. The only single phase matrix brought to the industrial application is glass, which is able to accumulate practically all RAW components but in limited concentrations. Prospects are related with some types of ceramics for immobilization of narrow fractions of RAW or individual radionuclides (for instance, minor actinides), as well as some types of low-temperature matrices (iron-phosphate, magnesium–potassium–phosphate, and geopolymers). Approaches to choosing the technology of waste form synthesis are considered. Perspectives of application of both high-temperature (cold-crucible induction melting, self-propagating high-temperature synthesis) methods and modified cementation technologies are demonstrated. It is noted that the final isolation of RAW from the biosphere suggests their disposal in underground repositories. The most difficult technical problem is the disposal of RAW containing long-lived radionuclides. It is shown that the quantitative assessment of repository safety with allowance for their characteristics and all possible processes and phenomena is required to substantiate the safe disposal of long-lived radionuclides.

Quantitative Safety and Health Assessment Based on Fuzzy Inference and AHP at Preliminary Design Stage

Quantitative assessment is the most important means to identify hazard potential and manage risk for an industrial process. The implement of quantitative assessment in the early stage will help to develop inherently safer process, eliminating the hazard and reduce the possibility of accidental chain events and the magnitude of consequences. In this paper, after reviewing the presently available assessment method, we present the disadvantages of current technology in several aspects. Focusing on the main disadvantage of subjectivity in two aspects of index valuing and weighting, which is a serious barrier to measure the real level of process safety, we propose a quantitative assessment method integrated fuzzy inference and Analytic Hierarchy Process(AHP) to quantify safety and health hazards of chemical process route in preliminary design stage. The purpose of integrating fuzzy inference into it is to reduce the subjectivity of index valuing system. The fuzzy inference system is designed without medium variable in order to eliminate its negative effect on assessment result. Index weighting is determined by AHP more objectively based on the ordering of inherent safety guidewords. Finally, the proposed method is applied to assessment nine competing routes of acetic acid manufacture to present its improvement.

Quantitative Assessment of Safety and Security of System Architectures for Cyberphysical Systems Using the NFR Approach

Cyberphysical systems (CPSs) are an integral part of modern societies since most critical infrastructures are controlled by these systems. CPSs incorporate computer-based and network-based technologies for the monitoring and control of physical processes. Two critically important properties of CPSs are safety and security. It is widely accepted that properties such as safety and security should be considered at the system design phase itself, particularly at the architectural level wherein such properties are embedded in the final system. However, safety and security are interrelated, and there seems to be a lack of techniques that consider both of them together. The nonfunctional requirement (NFR) approach is a technique that allows the simultaneous evaluation of both safety and security at the architectural level. In this paper, we apply the NFR approach to quantitatively evaluate the safety and security properties of an example CPS, i.e., an oil pipeline control system. We conclude that the NFR approach provides practical results that can be used by designers and developers to create safe and secure CPSs.

An approach to operational risk modeling and estimation of safety levels for deep water work class remotely operated vehicle—A case study with reference to ROSUB 6000

This paper presents a quantitative approach to operational risk modeling and estimation of safety integrity levels, required for the deep water electric work class remotely operated vehicle with reference to ROSUB6000 developed by the National Institute of Ocean Technology, India. ROSUB6000 is used for carrying out bathymetric surveys, gas hydrate surveys, poly-metallic nodule exploration, salvage operations, and meeting emergency response situations. The system is expected to be in operation for a period of 300h per year, and has to be extremely safe and reliable. Methods and models for the quantitative assessment of operational safety and estimation of safety integrity levels for ROV are seldom available in the deep water intervention industry. The safety instrumented functions implemented in the ROV should be able to meet the SIL requirements of specific mission. This study indicates that the required safety factors are implemented into the design of the state-of-the-art ROV ROSUB 6000, considering IEC 61508/61511 recommendations on Health, Safety and Environment and it is found that the system is able to meet the required SIL for seven identified functions. This paper gives the design and safety engineers in the ROV industry, an overview of the numerical operational risk assessment methods and safety-centered ROV engineering.

The Quantitative Safety Assessment and Evaluation for Safety-Critical Computer Systems

The rapid increase in computer-related technologies puts greater demands on the software-controlled systems. These demands place the software in total control over safety-critical systems. A fault in such a Safety-Critical Computer Systems (SCCS) can result in catastrophic concerns such as loss of life, harm, or equipment damage. In order to detect and prevent such faults, some safety standards, safety analysis and fault-tolerant techniques have been developed. Still, it requires adequate methodologies and frameworks to complete verification of these SCCS. In this work, the software safety is considered into 3 parts: Safety Modeling, Safety Measurement and Safety Management, with assurance lying down to develop high quality software for SCCS. The proposed methodology is SM-Cube (Safety Modeling, Safety Measurement and Safety Management) which is the Safety-Critical Computer Systems concerned. SM-Cube provides a clarified differentiation for assessing and evaluating the safety embedded into the software. SM-Cube consists of required processes and operations for developing SCCS free of faults. This proposed SM-cube has been applied to safety-critical software based Railroad Crossing Control System (RCCS) which is a laboratory prototype. The outcomes of the prototype confirmed that all critical operations have been safe and risk free. The development of the software based on the proposed SM-cube for RCCS have shown a simplified and improved safety-critical operations of the overall system performance