Assessment of Societal Risks Associated With Large Gas Transmission Pipeline Systems

2020 ◽  
Author(s):  
Dongliang Lu ◽  
Alex Tomic ◽  
Shahani Kariyawasam
Keyword(s):  
Risk Assessment ◽  
Natural Gas ◽  
Individual Risk ◽  
Risk Levels ◽  
Risk Criteria ◽  
Alternative Method ◽  
Societal Risk ◽  
Pipeline Systems ◽  
The Uk ◽  
Level Of Risk

Abstract Risk assessment is the process of risk analysis and evaluation. It is a required component of pipeline integrity management programs (IMP) and is generally the first step in most IMPs. For the risk assessment of natural gas pipelines, the primary concern is the safety of population near the pipeline right of way (ROW). TC Energy’s SWRA uses a quantitative risk assessment model that considers the effect of the thermal radiation due to ignited pipeline rupture and evaluate the consequence on the surrounding population. The overall risk is then evaluated using two specific risk criteria: societal risk and individual risk, with the societal risk measuring the overall level of risk to a community or a group of people and the individual risk measuring the level of risk to specific individuals who are present within the pipeline hazard zone. Natural gas pipeline systems often extend hundreds or even thousands of miles. As such, societal risk criteria for pipelines are typically defined based on a given length of pipeline segment, usually in 1 km or 1 mile (1.6 km). To assess the societal risk of actual pipelines, different approaches are taken on how the risk along the length of a pipeline should be aggregated and compared to the criteria. For example, the PD8010-3 standard in the UK recommends the societal risk of a pipeline through a community to be aggregated and then normalized to the unit length to be compared with criteria; whereas the Dutch regulation requires societal risk at the worst location to be used. In the current SWRA, the societal risk along the length of a pipeline going through development areas or communities is aggregated following the recommendation of the UK PD8010-3, where the risk is aggregated and normalized to the pipeline length. Due to the vast scale of the pipeline system, it is impractical to manually review all development along the pipelines for conducting societal risk assessment on a system wide basis. As such, extent of communities and development areas is determined by a computer program using a simple set of rules. It was found to have led to unsatisfying granularity in the societal risk assessment in certain situations, with some interaction lengths being too long and thus failing to identify the more critical section within the interaction length, and certain development lengths being too short and thus not very meaningful from a societal risk perspective. To overcome issues with the current societal risk assessment method in SWRA, an alternative method largely following the direction of the Dutch approach is introduced in this paper. In this alternative approach, the societal risk is evaluated continuously along a pipeline with a predefined a sliding length, and thus variations in the societal risk levels along the entire length of a pipeline, including the locations with the highest societal risk levels, can be identified. Implantation details and computational efficiency were discussed. The results from the alternative method were compared to that from the current method. The sensitivity of the sliding length method to the predefined sliding length was also investigated. The study showed that this alternative method improves the accuracy and granularity of the societal risk assessment in the SWRA, and, although it is relatively computational commanding, with an efficient implementation, is still practical even for very large gas transmission systems.

Target Reliability Levels for Design and Assessment of Onshore Natural Gas Pipelines

2004 ◽  
Author(s):  
Maher Nessim ◽  
Wenxing Zhou ◽  
Joe Zhou ◽  
Brian Rothwell ◽  
Martin McLamb
Keyword(s):  
Natural Gas ◽  
Risk Aversion ◽  
Individual Risk ◽  
Gas Pipelines ◽  
Detailed Consideration ◽  
Risk Levels ◽  
Natural Gas Pipelines ◽  
Risk Criteria ◽  
Societal Risk ◽  
Pipeline Design

This paper proposes a set of reliability targets that can be used in the design and assessment of onshore natural gas pipelines. The targets were developed as part of a PRCI-sponsored project that aims to establish reliability-based methods as a viable alternative for pipeline design and assessment. The proposed targets are calibrated to meet risk levels that are considered widely acceptable. The proposed criteria are based on a detailed consideration of both societal and individual risk criteria. Two societal risk criteria were considered; the first based on a fixed expectation of the number of fatalities and the second based on a risk aversion function as characterized by an F/N relationship. Societal risk criteria were calibrated to match or exceed the average safety levels implied by current codes. Individual risk criteria were based on published tolerable levels. The target reliability levels corresponding to the three criteria are presented and a recommended set of targets is presented.

Target Reliability Levels for Design and Assessment of Onshore Natural Gas Pipelines

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Maher Nessim ◽  
Wenxing Zhou ◽  
Joe Zhou ◽  
Brian Rothwell
Keyword(s):  
Natural Gas ◽  
Risk Aversion ◽  
Individual Risk ◽  
Gas Pipelines ◽  
Detailed Consideration ◽  
Risk Levels ◽  
Natural Gas Pipelines ◽  
Risk Criteria ◽  
Societal Risk ◽  
Pipeline Design

This paper proposes a set of reliability targets that can be used in the design and assessment of onshore natural gas pipelines. The targets were developed as part of a PRCI-sponsored project that aims to establish reliability-based methods as a viable alternative for pipeline design and assessment. The proposed targets are calibrated to meet risk levels that are considered widely acceptable. The proposed criteria are based on a detailed consideration of both societal and individual risk criteria. Two societal risk criteria were considered: the first based on a fixed expectation of the number of fatalities and the second based on a risk aversion function as characterized by a F/N relationship. Societal risk criteria were calibrated to match or exceed the average safety levels implied by current codes. Individual risk criteria were based on published tolerable levels. The target reliability levels corresponding to the three criteria are presented and a recommended set of targets is presented.

Technical safety: use of concept risk assessment for field development certainty

2019 ◽  
Vol 59 (2) ◽  
pp. 549
Author(s):  
Colin Crowley ◽  
Dave Ashton
Keyword(s):  
Risk Assessment ◽  
Design Feature ◽  
Safety Performance ◽  
Quantitative Risk Assessment ◽  
Individual Risk ◽  
Field Development ◽  
Risk Levels ◽  
Wide Range ◽  
Rule Sets ◽  
Risk Reduction Measures

As technology advances and field development possibilities grow, the need for earlier guidance on the safety performance of concept designs is greater than ever. The SNC-Lavalin concept risk assessment (CRA) tool is a transparent and rapidly deployable model that is based on sound, industry-accepted quantitative risk assessment (QRA) principles. From the earliest stages of field development, when conceptualisation may be vague and data sparse, a wide range and variety of design options can still be assessed effectively and ranked on their safety performance. The CRA tool is proprietary software initially developed with BP and Shell. The model was first calibrated against 10 detailed QRAs, but is regularly benchmarked and updated with the most current failure rate data and has been used on nearly 50 projects globally. The database now incorporates established rule sets from hundreds of detailed QRAs performed, including floating liquefied natural gas and floating storage regasification units. This paper presents a CRA case study for a generic remote offshore field with a range of development options from conventional to minimal offshore facilities. The model calculates the associated risks for the options considered and is presented in terms of individual risk per annum, temporary refuge impairment frequency and potential loss of life. The results highlight the effects of each individual design feature on risk levels by comparison of similar options side by side, noting the main risk contributors and allowing investigation of the benefits of risk reduction measures. This enables identification of the best design features from each of the options and allows an optimised design to be carried forward.

Risks of Risk Decisions

Science ◽  
1980 ◽  
Vol 208 (4448) ◽  
pp. 1114-1119 ◽  
Author(s):  
Chauncey Starr ◽  
Chris Whipple
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Decision Process ◽  
Cost Benefit ◽  
Risk Assessments ◽  
Individual Risk ◽  
Financial Cost ◽  
Technological Risk ◽  
Risk Criteria ◽  
Analytical Approaches

The analytical approaches utilized for evaluating the acceptability of technological risk originate from analogies to financial cost-benefit risk analysis. These analogies appear generally valid for viewing risk from a societal basis, but are not applicable to individual risk assessments. Conflicts arising from these different views of risk assessment provide insights to the origins of individual, intuitive evaluations. Societal risk decisions made under conflict represent political compromises, and the resulting decision process creates substantial conflict costs. The pragmatic use of quantitative risk criteria (safety targets) may be useful in reducing these costs.

scholarly journals NEW SAFETY STANDARDS FOR COASTAL FLOOD DEFENCES IN THE NETHERLANDS

2011 ◽  
Vol 1 (32) ◽  
pp. 11
Author(s):  
Sebastiaan N. Jonkman ◽  
Ruben Jongejan ◽  
Bob Maaskant ◽  
Han Vrijling
Keyword(s):  
The Netherlands ◽  
Cost Benefit ◽  
Policy Implications ◽  
Individual Risk ◽  
Safety Policy ◽  
Risk Levels ◽  
Safety Standards ◽  
Annual Probability ◽  
Societal Risk ◽  
The Individual

The Dutch government is in the process of revising its flood safety policy. The current safety standards for flood defences in the Netherlands are largely based on the outcomes of cost-benefit analyses. Loss of life has not been considered separately in the choice for current standards. This article presents the results of a research project that evaluated the potential roles of two risk metrics, individual and societal risk, to support decision-making about new flood safety standards. These risk metrics are already used in the Dutch major hazards policy for the evaluation of risks to the public. Individual risk concerns the annual probability of death of a person. Societal risk concerns the probability of an event with many fatalities. Technical aspects of the use of individual and societal risk metrics in flood risk assessments as well as policy implications are discussed. Preliminary estimates of nationwide levels of societal risk are presented. Societal risk levels appear relatively high in the South Western part of the country where densely populated dike rings are threatened by a combination of river and coastal floods. Options for the application of the individual and societal risk in the new flood safety policy are presented and discussed.

Safety Risk Acceptance Criteria for Pipelines

2020 ◽  
Author(s):  
Maher Nessim ◽  
Shahani Kariyawasam
Keyword(s):  
Risk Assessment ◽  
Oil And Gas ◽  
Task Force ◽  
Quantitative Risk Assessment ◽  
Background Information ◽  
Individual Risk ◽  
Acceptance Criteria ◽  
Safety Risk ◽  
Wide Range ◽  
Societal Risk

Abstract The lack of established acceptance criteria has been one of the key challenges to the application of quantitative risk assessment (QRA) techniques in the Canadian pipeline industry. While a wide range of such criteria have been developed and published, it remains difficult for most operators to commit to specific criteria because such criteria may not be acceptable to all stakeholders. Recognizing this limitation, the Canadian Standards Association formed a Risk Management Task Force (RMTF) under the Technical Committee for the Z662 Standard on the Oil and Gas Pipeline Systems to propose criteria for potential inclusion in its non-mandatory Annex on Risk Assessment. This paper describes the criteria that have been developed by the RMTF and provides the background information needed for users to understand and use them correctly. The discussion includes: a summary of the measures used to quantify the safety risk associated with an ignited product release; a summary of established international and Canadian criteria that have been considered; a description and interpretation of the ALARP (As Low As Reasonably Practicable) principle; and the rationale used by the RMTF to select specific individual risk and societal risk criteria for CSA Z662. The proposed criteria are also compared to the criteria underpinning other risk-based parts of the Z662 Standard, including Annexes C and O. Guidance is provided on the analysis assumptions, methods and parameters required to ensure that the risk calculations produce results that are consistent with the definition and intent of the criteria. Key issues addressed by the guidance include the definition of individual risk (i.e. location risk versus personal risk), the pipeline length over which the frequency versus number of fatalities (F-N) relationship representing societal risk is calculated, and the effect of population density averaging over the pipeline length.

Reliability Based Design and Assessment for Location-Specific Failure Threats With Application to Natural Gas Pipelines

2006 ◽  
Author(s):  
Maher Nessim ◽  
Wenxing Zhou ◽  
Joe Zhou ◽  
Brian Rothwell
Keyword(s):  
Natural Gas ◽  
Individual Risk ◽  
Gas Pipelines ◽  
Limit States ◽  
Integrity Assessment ◽  
Natural Gas Pipelines ◽  
Risk Criteria ◽  
Reliability Based Design ◽  
Unstable Slope ◽  
The Individual

The acceptance criteria used in Reliability Based Design and Assessment (RBDA) are defined as a set of reliability targets (where reliability is defined as 1.0 minus the probability of failure). Because of the linear nature of pipeline systems, reliability targets are defined on a per km-year basis. Such targets are directly applicable to failure causes (or limit states) that are equally likely to occur anywhere along a segment of the pipeline (e.g. equipment impact or yielding/rupture of defect-free pipe under internal pressure). They are, however, not directly applicable for design and assessment situations involving limit states that apply at known specific locations. Examples include design for geotechnical loads on a particular unstable slope or integrity assessment of specific corrosion defects based on in-line inspection data. In previous work, reliability targets for natural gas pipelines have been developed on the basis of appropriate societal and individual risk criteria. This paper describes an approach to adapt these targets, and demonstrate compliance with them, for location-specific limit states. The approach is based on using separate checks to ensure that the individual and societal risk criteria underlying the targets are met. An example is included to demonstrate application of the approach to design a pipeline on an unstable slope.

Managing Cultural Risks

2021 ◽  
pp. 286-295
Keyword(s):  
Risk Assessment ◽  
Risk Management ◽  
Cost Effective ◽  
Analysis Method ◽  
Risk Criteria ◽  
Organizational Risk ◽  
Iso 31000 ◽  
Risk Management Methodology ◽  
Risk Assessment And Analysis ◽  
Level Of Risk

Risk assessment is a process that allows us to understand risks, define risk criteria, assess the probability and the consequences of that risk occurring, define a level of risk we can tolerate and afford, and define a cost-effective and efficient mitigation treatment. The authors provide a risk assessment and analysis method that the reader can use to (1) build cultural risk into your organizational risk management profile and (2) adapt the organization's risk management profile to include cultural risks. The method builds upon but extends the ISO 31000/31010 risk management methodology to determine the level of cultural risk your organization is carrying. The authors walk through and translate each of the seven steps to account for cultural risks.

scholarly journals Developing Tolerable Risk Criteria for Gas Transmission Pipelines

2000 ◽  
Author(s):  
Jose L. Martinez ◽  
Enrique Rodriguez
Keyword(s):  
Risk Assessment ◽  
Risk Management ◽  
Natural Gas ◽  
Management Team ◽  
Analysis Tool ◽  
Management Philosophy ◽  
Risk Criteria ◽  
Tolerable Risk ◽  
Assessment Approach ◽  
Comprehensive Study

After completing an extensive risk assessment stage, PGPB’s Risk Management Team was ready to move towards Risk Management philosophy. Comparing PEMEX’s algorithm with the typical values of the industry enabled the risk assessment approach adopted in PGPB. As a result of a comprehensive study that gathered several of the users of the same analysis tool, an optimised and normalised algorithm was obtained to support the risk assessment programme and comply with the company’s policies. The risk assessment stage included more than 1,700 kilometres of LPG pipelines and 3,500 kilometres of natural gas. This stage was granted as final until consistent risk values were achieved in every segment section. To move into the Risk Management stage a comprehensive study was performed to define tolerable risk criteria for PGPB pipeline network.

A Practical Method for the Evaluation of Societal Risk in the Context of the International Maritime Organization's Safety Level Approach

2018 ◽  
Vol 71 (4) ◽  
pp. 919-932
Author(s):  
Molin Sun ◽  
Zhongyi Zheng ◽  
Longhui Gang
Keyword(s):  
Practical Method ◽  
Individual Risk ◽  
Safety Level ◽  
Risk Criteria ◽  
Cruise Ships ◽  
Dynamic Factors ◽  
Passenger Ships ◽  
Societal Risk ◽  
Rule Making

The Safety Level Approach (SLA) is a structured application of risk-based methodologies for the International Maritime Organization's (IMO's) rule-making process. When the SLA is applied, safety goals have to be provided. In order to set appropriate levels for safety goals, it is necessary to measure the tolerance degree of the current safety level. Based on the consistency with individual risk criteria and the principle of continuous improvement, this paper proposes an approach to establish the societal risk criteria, which can be used for setting safety goals in the context of the IMO's SLA. Furthermore, by defining dynamic factors to express risk aversion, a method for tolerance measurement of the current societal risk is developed. Finally, a case study into the societal risk evaluation of cruise ships and Roll-On Roll-Off (RO-RO) passenger ships is conducted.

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