On the Use of Proper Fragility Models for Quantitative Seismic Risk Assessment of Process Plants in Seismic Prone Areas

2017 ◽  
Author(s):  
Silvia Alessandri ◽  
Antonio C. Caputo ◽  
Daniele Corritore ◽  
Giannini Renato ◽  
Fabrizio Paolacci ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Seismic Risk ◽  
Structural Damage ◽  
Fragility Curves ◽  
Probabilistic Method ◽  
Quantitative Risk Assessment ◽  
Actual Process ◽  
Consequence Analysis ◽  
Process Plant ◽  
Process Plants

Quantitative Risk Assessment (QRA) is a classical method for the calculation of risk in process plants, which is based on the logic of the consequence analysis. This intrinsically probabilistic method has been thought for classical accident conditions, where the damage events and the relevant consequences start from a preselected component and a standard loss of containment (LOC) and follow all possible scenarios for the calculation of individual and societal risk. This final risk metric is usually expressed in terms of probability of fatality in a specific location of the surrounding area or a certain number of fatalities in the area surrounding the accident. In presence of Na-Tech events, like earthquakes, a multi-source condition can be caused by multi-damage conditions simultaneously involving more than one equipment, which in turn can generate a multiple-chain of events and consequences. In literature, several attempts of modifying the classic QRA approach to account for this important aspect have been formalized without converging toward a unified approach. In this paper, a fragility-based method for Quantitative Seismic Risk Analysis (QSRA) of a process plant is investigated. This method takes into account all possible damage/losses of containment conditions in the most critical equipment, e.g., storage tanks. Fragility curves, which are analytically evaluated for each unit with respect to its seismic damage conditions, are utilized inside the procedure. The Monte Carlo Simulation (MCS) method is then used with the aim to follow all steps of QSRA. In particular, starting from the seismic hazard curve of the site where the plant is placed, a multi-level approach is proposed. In this approach, the first level is represented by the components seismically damaged, whereas the following levels are treated through a classical consequence analysis, including the propagation of multiple simultaneous and interacting chains of accidents. These latter are applied by defining proper correspondences for all relevant equipment between structural damage (i.e., limit states) and LOC events. The application of the method to an actual process plant permits to investigate its high potentiality and the dependency of the risk assessment from the proper fragility models.

Seismic Quantitative Risk Assessment of Process Plants Through Monte Carlo Simulations

2016 ◽  
Author(s):  
Silvia Alessandri ◽  
Antonio C. Caputo ◽  
Daniele Corritore ◽  
Renato Giannini ◽  
Fabrizio Paolacci
Keyword(s):  
Risk Assessment ◽  
Monte Carlo ◽  
Seismic Risk ◽  
Quantitative Risk Assessment ◽  
Damage Propagation ◽  
Process Plants ◽  
Physical Effects ◽  
Level 1 ◽  
Level I ◽  
Seismic Hazard Curve

This paper describes the application of Monte Carlo method for the quantitative seismic risk assessment (QSRA) of process plants. Starting from the seismic hazard curve of the site where the plant is located, the possible chains of accidents are modelled using a sequence of propagation levels in which Level 0 is represented by the components directly damaged by the earthquake whereas the subsequent Levels represent the resulting consequence propagation. In greater detail all units damaged by energy and materials releases from level 0 units are included in level 1 and so forth, so that referring to process units belonging to a generic i-th Level, they are damaged by level (i-1) units and damage units of level (i+1). The sequence of levels represents the damage propagation across the plant through any multiple interacting sequences of accidents. For each unit a damage (DM) - loss of containment (LOC) matrix is generated allowing to estimate the amount of energy and material releases as well as resulting physical effects based on which the scenario at i-th level is generated. The process stops when no further damage propagation is allowed.

Impact of downward releases on the risk profile in hydrocarbon process plants

2020 ◽  
Vol 60 (1) ◽  
pp. 82
Author(s):  
Fariba Askari ◽  
Colin Crowley ◽  
Hojat Kord
Keyword(s):  
Risk Assessment ◽  
Sensitivity Analysis ◽  
High Pressure ◽  
Risk Profile ◽  
Quantitative Risk Assessment ◽  
Consequence Analysis ◽  
Simplifying Assumptions ◽  
Process Plants ◽  
The Cost

Quantitative risk assessment (QRA) calculations for major hazard installations often involve consequence analysis calculations for thousands of events, and therefore, some simplifying assumptions are generally required. The simplifications are usually designed to make the analysis reasonably practicable and reduce the cost of the QRA. Nevertheless, the overall methodology and the applied parameters should be chosen conservatively to cover possible uncertainties. One of the key assumptions in many QRAs is the release direction, which is usually assumed to be horizontal. This is generally assumed to provide a conservative representation of all other possible release directions, which may occur vertically (upward or downward) or at an angle. A sensitivity analysis has been performed and presented in this paper to investigate how different release direction assumptions affect the results of consequence analysis, and eventually, QRA outcomes, i.e. individual and societal risk results. A high-pressure hydrocarbon system is considered as a case study and SNC-Lavalin’s (formerly Atkins) in-house QRA software, ‘RiskTool’, has been used to carry out the QRA modelling. The overall conclusion is that the assumption that all releases are horizontal may lead to a significant underprediction of risks for some types of high-pressure release events. This is because an unimpeded horizontal jet may entrain air, and hence, dilute much more rapidly than a jet that impinges on the ground or nearby obstacles.

scholarly journals Risk Assessment and Deployment for Safety Showers and Eyewash Stations in the Process Plant Industry

2021 ◽  
Vol 18 (16) ◽  
pp. 8707
Author(s):  
Jae-Young Choi ◽  
Sang-Hoon Byeon
Keyword(s):  
Risk Assessment ◽  
Industrial Hygiene ◽  
Process Equipment ◽  
Process Safety ◽  
Plant Industry ◽  
Hazardous Chemicals ◽  
Safety Improvement ◽  
Process Plant ◽  
Process Plants ◽  
Operator Safety

Safety showers and eyewash stations are equipment used for primary washing if their operator is exposed to hazardous chemicals. Therefore, safety showers and eyewash stations should be installed to ensure operator safety in process plants with excessive hazardous chemicals. International guidelines related to safety showers and eyewash stations are introduced in ANSI Z358.1, BS EN 15154, and German DIN 12899-3:2009, but only mechanical specifications regarding safety showers and eyewash stations are suggested. As such, there are currently no engineering guidelines, books, or technical journal papers requiring safety showers or eyewash stations and their efficient deployment. Thus, this study conducted risk assessment from an industrial hygiene perspective, suggesting which process equipment requires a safety shower and eyewash, including their economical and efficient deployment for operator safety. In industry, safety showers and eyewash stations are considered part of the process safety field; this study attempted to contribute to the safety improvement of operators by applying risk assessment of the industrial hygiene field. More studies are needed that contribute to operators’ safety by incorporating industrial hygiene fields for other process safety fields, including safety showers and eyewash stations.

Seismic risk assessment of RC curved bridges through fragility curves

2019 ◽  
Author(s):  
Nina N. Serdar ◽  
Jelena R. Pejovic ◽  
Radenko Pejovic ◽  
Miloš Knežević
Keyword(s):  
Risk Assessment ◽  
Urban Areas ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Curved Bridges ◽  
Damage State ◽  
Seismic Risk Assessment ◽  
Probability Of Exceedance ◽  
Damage States

<p>It is of great importance that traffic network is still functioning in post- earthquake period, so that interventions in emergency situations are not delayed. Bridges are part of the traffic system that can be considered as critical for adequate post-earthquake response. Their seismic response often dominate the response and reliability of overall transportation system, so special attention should be given to risk assessment for these structures. In seismic vulnerability and risk assessment bridges are often classified as regular or irregular structures, dependant on their configuration. Curved bridges are considered as irregular and unexpected behaviour during seismic excitation is noticed in past earthquake events. Still there are an increasing number of these structures especially in densely populated urban areas since curved configuration is often suitable to accommodate complicated location conditions. In this paper special attention is given to seismic risk assessment of curved reinforce concrete bridges through fragility curves. Procedure for developing fragility curves is described as well as influence of radius curvature on their seismic vulnerability is investigated. Since vulnerability curves provide probability of exceedance of certain damage state, four damage states are considered: near collapse, significant damage, intermediate damage state, onset of damage and damage limitation. As much as possible these damage states are related to current European provisions. Radius of horizontal curvature is varied by changing subtended angle: 25 °, 45 ° and 90 °. Also one corresponding straight bridge is analysed. Nonlinear static procedure is used for developing of fragility curves. It was shown that probability of exceedance of certain damage states is increased as subtended angle is increased. Also it is determined that fragility of curved bridges can be related to fragility of straight counterparts what facilitates seismic evaluation of seismic vulnerability of curved bridges structures.</p>

scholarly journals Resilience of Process Plant: What, Why, and How Resilience Can Improve Safety and Sustainability

2020 ◽  
Vol 12 (15) ◽  
pp. 6152 ◽  
Author(s):  
Hans Pasman ◽  
Kedar Kottawar ◽  
Prerna Jain
Keyword(s):  
Risk Assessment ◽  
Oil And Gas ◽  
Research Work ◽  
Business Environment ◽  
Warning Signals ◽  
Plant Safety ◽  
Chemical Manufacturing ◽  
Process Plant ◽  
Process Plants ◽  
Proactive Measures

Resilience is the ability to restore performance after sustaining serious damage by a usually unexpected threat. This paper analyzes resilience of process plants as there are oil and gas refining, chemical manufacturing, power-producing plants, and many more. Over the years, plant safety has shifted from retrospective to proactive measures. Safety is important from many points of view, such as protection of workforce and nearby population, but certainly too from an economical and sustainability aspect. Pro-action requires predictive insight of what in the process can go wrong because of internal or external disruptive disturbance. Over the years, to that end, much effort was spent developing risk assessment methods and management. However, risk assessment has proven to be fallible because of various uncertainties and not the least by overlooked or unknown threats. To protect against those upsetting threats, measures can be taken up to a certain limit. These start in designing error-tolerant equipment able to be receptive to early warning signals during operations, responding to those with ‘plasticity’ of mind (that is, an organization and its leadership especially able to think ‘outside-the box’ for coping with unexpected situations), and finally, to deploy effective emergency response and able to recover from damage quickly. The paper presents a summary/review of nearly a decade of research work at the Mary Kay O’Connor Process Safety Center at the Texas A&M University to develop the concept and the techniques to realize a resilient plant, so far with a focus on chemical plant. It is, however, still a ‘work-in-progress’; potential is large. Besides the conceptual details, cases are presented that show how human and technical factors, combined in a socio-technical system, can lead to a broader plant safety insight enabling more effective risk control and increased resilience. These cases have up to now only considered warning signals and possible management action, while still limited to internal threats. Hence, aspects of equipment design and recovery should be further considered, also in the light of the dynamics of present-day business environment.

Quantitative Risk Assessment in Process Plant

1997 ◽  
Vol 47 (2) ◽  
pp. 197-205 ◽  
Author(s):  
C. Rajagopal ◽  
A. K. Jain
Keyword(s):  
Risk Assessment ◽  
Quantitative Risk Assessment ◽  
Process Plant

Numerical Simulation of Seismic Risk and Loss Propagation Effects in Process Plants: An Oil Refinery Case Study

2017 ◽  
Author(s):  
Antonio C. Caputo ◽  
Alessandro Vigna
Keyword(s):  
Risk Assessment ◽  
Seismic Risk ◽  
Production Capacity ◽  
Industrial Process ◽  
Oil Refinery ◽  
Quantitative Methodology ◽  
Seismic Risk Assessment ◽  
Technical Standards ◽  
Process Plants

Process plants are vulnerable to natural hazards and, in particular, to earthquakes. Nevertheless, the quantitative assessment of seismic risk of process plants is a complex task because available methodologies developed in the field of civil and nuclear engineering are not readily applicable to process plants, while technical standards and regulations do not establish any procedure for the overall seismic risk assessment of industrial process plants located in earthquake-prone areas. This paper details the results of a case study performing a seismic risk assessment of an Italian refinery having a 85,000 barrels per day production capacity, and a storage capacity of over 1,500,000 m3. The analysis has been carried out resorting to a novel quantitative methodology developed in the framework of a European Union research program (INDUSE 2 SAFETY). The method is able to systematically generate potential starting scenarios, deriving from simultaneous interactions of the earthquake with each separate equipment, and to account for propagation of effects between distinct equipment (i.e. Domino effects) keeping track of multiple simultaneous and possibly interacting chains of accidents. In the paper the methodology, already described elsewhere, is briefly resumed, and numerical results are presented showing relevant accident chains and expected economic loss, demonstrating the capabilities of the developed tool.

QUANTITATIVE RISK ASSESSMENT FOR COLLISIONS INVOLVING DOUBLE HULL OIL TANKERS

2021 ◽  
Vol 156 (A2) ◽  
Author(s):  
S A M Youssef ◽  
S T Ince ◽  
Y S Kim ◽  
J K Paik ◽  
F Chang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Structural Damage ◽  
Human Life ◽  
Quantitative Risk Assessment ◽  
Environmental Damage ◽  
Total Risk ◽  
Formal Safety Assessment ◽  
Environmental Damages ◽  
Oil Tankers ◽  
Double Hull

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organization’s (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario’s oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.

scholarly journals Impact of wildfires on Canada's oilsands facilities

2018 ◽  
Author(s):  
Nima Khakzad
Keyword(s):  
Risk Assessment ◽  
Global Warming ◽  
Oil And Gas ◽  
The Other ◽  
Quantitative Risk Assessment ◽  
Assessment Framework ◽  
Dynamic Risk ◽  
Dynamic Risk Assessment ◽  
Process Plants ◽  
Increasing Risk

Abstract. Exponential growth of oil and gas facilities in wildlands from one side and an anticipated increase of global warming from the other have exposed such facilities to an ever-increasing risk of wildfires. Extensive oilsands operations in Canadian wildlands especially in the Province of Alberta along with the recent massive wildfires in the province requires the development of quantitative risk assessment (QRA) methodologies which are presently lacking in the context of wildfire-related technological accidents. The present study is an attempt to integrate Canadian online wildfire information systems with current QRA techniques in a dynamic risk assessment framework for wildfire-prone process plants. The developed framework can easily be customized to other process plants potentially exposed to wildfires worldwide provided that the required wildfire information is available.

Sign in / Sign up

Export Citation Format

Share Document