The Effects of Corrosion Measurement Error on a Safety Risk Assessment: A TransGas Case Study

2014 ◽  
Author(s):  
Daryl Bandstra ◽  
Corey Gorrill
Keyword(s):  
Risk Assessment ◽  
Risk Measures ◽  
Quantitative Risk Assessment ◽  
Probability Models ◽  
Corrosion Failure ◽  
Safety Risk ◽  
Risk Levels ◽  
Transmission Pipeline ◽  
Operating Risk ◽  
The Impact

The risk of pipeline failure is a measure of the state of knowledge of the pipeline; improved knowledge of the pipeline reduces the uncertainty and therefore can reduce the associated risk. Specifically for corrosion defects, the knowledge of the number and size of defects is often obtained using in-line inspection tools which have uncertainty associated with their measurement capabilities. Quantitative Risk Assessment (QRA) is a methodology that objectively assesses a range of pipeline integrity threats including the threat of corrosion failure. QRA can incorporate the impact of significant sources of analysis uncertainty, such as feature sizing in risk estimates. This paper discusses an application of QRA used to evaluate the operating risk of high pressure transmission pipeline segments in the TransGas system. Specific examples are described in which the inspection tool sizing uncertainty was shown to exert a significant influence on the calculated risk levels. In carrying out the analysis, the failure probability models selected were dependent on the nature of the integrity threat and the type of information available for each pipeline. For the assessment of corrosion integrity, the results of in-line inspections were used directly in determining failure likelihood. For the other threats including equipment impact, geotechnical hazards, manufacturing cracks and stress corrosion cracking, the probability of failure was estimated from historical failure rates with adjustments to reflect line-specific conditions. Failure consequences were estimated using models that quantify the safety implications of loss of containment events. Using these models, safety risk measures were calculated along the length of each pipeline. The results of the analysis show the benefit of the use of inspection technologies with improved sizing accuracy, in terms of reduction in expected operating risk.

A Comparison of Inherent Risk Levels in ASME B31.8 and UK Gas Pipeline Design Codes

2006 ◽  
Author(s):  
Graham Goodfellow ◽  
Jane Haswell
Keyword(s):  
Risk Assessment ◽  
Radiation Effects ◽  
Assessment Methods ◽  
Gas Pipeline ◽  
Quantitative Risk Assessment ◽  
Design Codes ◽  
Risk Levels ◽  
Integrity Management ◽  
Pipeline Design ◽  
The Impact

The approach to gas pipeline risk and integrity management in the US, involving the development of integrity management plans for High Consequence Areas (HCA), is usually qualitative, as outlined in ASME B31.8S. Depending on the engineering judgement of the assessment team this can lead to a wide variety of results making risk comparison between pipelines difficult. Qualitative risk ranking methods are popular in Europe, but quantitative risk assessment (QRA) is also used for setting acceptable risk levels and as an input to risk and integrity management planning. It is possible to use quantitative risk assessment methods to compare the levels of risk inherent in different pipeline design codes. This paper discusses the use of pipeline quantitative risk assessment methods to analyse pipelines designed to ASME B31.8 and UK IGE/TD/1 (equivalent to PD 8010, published by BSI, for the design of gas pipelines) codes. The QRA utilises predictive models for consequence assessment, e.g. pipeline blowdown and thermal radiation effects, and failure frequency, in determining the risk levels due to an operational pipeline. The results of the analysis illustrate how the risk levels inherent in the two codes compare for different class locations & minimum housing separation distances. The impact of code requirements on design factor, depth of burial, population density and the impact of third party activity on overall risk levels are also discussed.

Applying the risk principle to optimize accuracy and equity in correctional risk assessment: Results From a Simulation

2021 ◽  
pp. 0306624X2098652
Author(s):  
Grant Duwe
Keyword(s):  
Risk Assessment ◽  
Predictive Accuracy ◽  
Ethnic Disparities ◽  
Simulated Data ◽  
Risk Assessments ◽  
Risk Level ◽  
Risk Levels ◽  
Risk Principle ◽  
Changes In Risk ◽  
The Impact

As the use of risk assessments for correctional populations has grown, so has concern that these instruments exacerbate existing racial and ethnic disparities. While much of the attention arising from this concern has focused on how algorithms are designed, relatively little consideration has been given to how risk assessments are used. To this end, the present study tests whether application of the risk principle would help preserve predictive accuracy while, at the same time, mitigate disparities. Using a sample of 9,529 inmates released from Minnesota prisons who had been assessed multiple times during their confinement on a fully-automated risk assessment, this study relies on both actual and simulated data to examine the impact of program assignment decisions on changes in risk level from intake to release. The findings showed that while the risk principle was used in practice to some extent, the simulated results showed that greater adherence to the risk principle would increase reductions in risk levels and minimize the disparities observed at intake. The simulated data further revealed the most favorable outcomes would be achieved by not only applying the risk principle, but also by expanding program capacity for the higher-risk inmates in order to adequately reduce their risk.

Design of a risk assessment methodology for the introduction of invasive species from ship ballast waters

2016 ◽  
Vol 27 (5) ◽  
pp. 474-490 ◽  
Author(s):  
Abderrahmane Bouda ◽  
Nour El Islam Bachari ◽  
Lylia Bahmed ◽  
Ryad Boubenia
Keyword(s):  
Risk Assessment ◽  
Invasive Species ◽  
Ballast Water ◽  
Quantitative Risk Assessment ◽  
Content Type ◽  
International Convention ◽  
Environmental Similarity ◽  
Process Factors ◽  
Shipping Traffic ◽  
The Impact

Purpose – Ballast water of merchant ship is a source of introduction of invasive species around the globe. The purpose of this paper is to present a quantitative risk assessment applied to a model port, the Port of Arzew in Algeria, and based on an analysis of this port’s shipping traffic. Design/methodology/approach – The risk assessment for introduction of invasive species is interpreted in the form of a probabilistic process, with a combination of two probabilities. The first probability is related to the ability of a species to arrive to the destination (recipient port), depending on the quantity of water ballast discharged and the duration of voyage. The second one is based on the species ability to survive in their new environment, which depends on the environmental similarity between donor port and Arzew port. Findings – This assessment’s outcome consists on a classification of scenarios regarding their acceptability. Consequently, it helped to classify donor ports according to a risk scale, from low risk to high-risk donor ports. Research limitations/implications – The phenomenon of invasion of aquatic species is a complex process. Factors such as adaptation and tolerance of species, the attendance or absence of predators, were not taken into account in this study. Practical implications – This study could be used by the maritime administration as a decision-making tool regarding the issue of exemptions under the IMO International Convention on the Management of Ballast Water and Sediments 2004. Originality/value – This is one of the first known studies in Algeria and dealing with ballast water management. The results of this assessment provide useful information to policy makers, in order to develop a national strategy to reduce the impact of shipping pollution on the marine environment.

FDA-iRISK—A Comparative Risk Assessment System for Evaluating and Ranking Food-Hazard Pairs: Case Studies on Microbial Hazards

2013 ◽  
Vol 76 (3) ◽  
pp. 376-385 ◽  
Author(s):  
YUHUAN CHEN ◽  
SHERRI B. DENNIS ◽  
EMMA HARTNETT ◽  
GREG PAOLI ◽  
RÉGIS POUILLOT ◽  
...  
Keyword(s):  
Public Health ◽  
Risk Assessment ◽  
Case Studies ◽  
Assessment System ◽  
Process Models ◽  
Control Measures ◽  
Quantitative Risk Assessment ◽  
The Public ◽  
Life Years ◽  
The Impact

Stakeholders in the system of food safety, in particular federal agencies, need evidence-based, transparent, and rigorous approaches to estimate and compare the risk of foodborne illness from microbial and chemical hazards and the public health impact of interventions. FDA-iRISK (referred to here as iRISK), a Web-based quantitative risk assessment system, was developed to meet this need. The modeling tool enables users to assess, compare, and rank the risks posed by multiple food-hazard pairs at all stages of the food supply system, from primary production, through manufacturing and processing, to retail distribution and, ultimately, to the consumer. Using standard data entry templates, built-in mathematical functions, and Monte Carlo simulation techniques, iRISK integrates data and assumptions from seven components: the food, the hazard, the population of consumers, process models describing the introduction and fate of the hazard up to the point of consumption, consumption patterns, dose-response curves, and health effects. Beyond risk ranking, iRISK enables users to estimate and compare the impact of interventions and control measures on public health risk. iRISK provides estimates of the impact of proposed interventions in various ways, including changes in the mean risk of illness and burden of disease metrics, such as losses in disability-adjusted life years. Case studies for Listeria monocytogenes and Salmonella were developed to demonstrate the application of iRISK for the estimation of risks and the impact of interventions for microbial hazards. iRISK was made available to the public at http://irisk.foodrisk.org in October 2012.

Propagation and Delegation of Rights in Access Controls and Risk Assessment Techniques

2007 ◽  
pp. 328-337
Author(s):  
Saravanan Muthaiyah
Keyword(s):  
Risk Assessment ◽  
Access Control ◽  
Web Security ◽  
Quantitative Risk Assessment ◽  
New Paradigm ◽  
Risk Levels ◽  
Qualitative Risk Assessment ◽  
Access Controls ◽  
Assessment Techniques ◽  
Access Rights

Access control methods have been improvised over time, but one area that remains quite grey is the concept of assessing risk levels before any type of access rights are granted. This is relatively a new paradigm in the research of semantic Web security, and new methodologies for this effort are being studied. In this chapter, we will see how qualitative risk assessment (Nissanke & Khayat, 2004) and quantitative risk assessment are carried out. The purpose is to have different methods of assessment for better grant of access control rights and permissions. New examples based on the model described (Nissanke & Khayat, 2004) are used to illustrate the concept. A new quantities technique is also added to complement the qualitative techniques.

scholarly journals Aggregated Risk Assessment and Survey for Risk Reduction in Oil Terminals

2021 ◽  
Vol 13 (21) ◽  
pp. 12169
Author(s):  
Robertas Alzbutas ◽  
Mindaugas Vaisnoras ◽  
Inga Saruniene ◽  
Ricardas Krikstolaitis ◽  
Mindaugas Valincius ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Risk Reduction ◽  
Hazard Analysis ◽  
Quantitative Risk Assessment ◽  
Study Results ◽  
Risk Aggregation ◽  
Risk Reduction Measures ◽  
The Impact

One of the goals of any oil terminal is to make a business while avoiding hazardous events and harmful effects for both humans and the environment. This can be achieved by creating a safe working place as well as by performing safe and acceptable activities regarding the impact on surrounding objects, including residential and industrial areas. The aim of the hazard analysis of the oil terminal is to assess the risks related to hazardous events or phenomena and to evaluate whether the assessed risks are acceptable. The hazard analysis and assessment of risk are also used for risk reduction while examining and limiting hazardous scenarios that, for instance, involve the loss-of-containment of flammable or combustible material. In this paper, the authors aim to contribute to risk research by providing a comprehensive methodology of risk assessment for oil terminals with case study results and discussion on features of the methodology, risk aggregation, its applicability for risk reduction, and industrial interests. The performed study considered the “Klaipedos Nafta AB” (an operator of the Klaipeda Oil Terminal, Lithuania) case study regarding hazardous materials that might be released from various tanks, devices, and associated pipelines. The performed quantitative risk assessment has enabled the determination of the probability regarding whether releases would ignite and, for instance, cause explosion. In the case study, the estimate of probability, i.e., the frequency, and the possible consequences of the hazardous events were evaluated, and both mitigation and risk reduction measures were also considered.

Validating ecological risk assessments for fisheries: assessing the impacts of turtle excluder devices on elasmobranch bycatch populations in an Australian trawl fishery

2006 ◽  
Vol 57 (4) ◽  
pp. 395 ◽  
Author(s):  
Shane P. Griffiths ◽  
David T. Brewer ◽  
Don S. Heales ◽  
David A. Milton ◽  
Ilona C. Stobutzki
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Absolute Risk ◽  
Assessment Method ◽  
Quantitative Risk Assessment ◽  
Trawl Fishery ◽  
Recovery Potential ◽  
Risk Assessment Method ◽  
Fishing Impacts ◽  
The Impact

Demonstrating ecological sustainability is a challenge for fisheries worldwide, and few methods can quantify fishing impacts on diverse, low value or rare species. The current study employed a widely used ecological risk assessment method and incorporated new data to assess the change in sustainability of species following the introduction of Turtle Excluder Devices (TEDs) in Australia’s Northern Prawn Fishery (NPF). Population recovery ranks changed for 19 of the 56 elasmobranch species after the introduction of TEDs, with nine species showing an increase in sustainability. Unexpectedly, ten species showed a decrease in sustainability. This was due to TEDs successfully excluding large animals from the catch, resulting in a lower mean length at capture, which reduced the recovery ranks for two criteria relying on length data. This falsely indicates that TEDs increase the impact on pre-breeding animals, thus reducing the recovery potential of these species. The results demonstrate that existing attribute-based risk assessment methods may be inadequate for reflecting even the most obvious changes in fishing impacts on bycatch species. Industry and management can benefit greatly from an approach that more accurately estimates absolute risk. The development and requirements of a new quantitative risk assessment method to be developed for the NPF, and applicable to fisheries worldwide, are discussed.

Risk Assessment Overrides: Shuffling the Risk Deck Without Any Improvements in Prediction

2020 ◽  
Vol 47 (12) ◽  
pp. 1609-1629
Author(s):  
Thomas H. Cohen ◽  
Christopher T. Lowenkamp ◽  
Kristin Bechtel ◽  
Anthony W. Flores
Keyword(s):  
Risk Assessment ◽  
Risk Prediction ◽  
Risk Classification ◽  
Federal System ◽  
Sex Offenses ◽  
Supervision System ◽  
Risk Levels ◽  
Risk Reclassification ◽  
The Impact

In the federal supervision system, officers have discretion to depart from the risk designations provided by the Post Conviction Risk Assessment (PCRA) instrument. This component of the risk classification process is referred to as the supervision override. While the rationale for allowing overrides is that actuarial scores cannot always capture an individual’s unique characteristics, there is relatively limited literature on the actual effects of overrides on an actuarial tool’s predictive efficacies. This study examines overrides in the federal system by assessing the extent to which risk levels are adjusted through overrides as well as the impact of overrides on the PCRA’s risk prediction effectiveness. Findings show that nearly all overrides lead to an upward risk reclassification, that overrides tend to place substantial numbers of persons under federal supervision (especially those convicted of sex offenses) into the highest supervision categories, and that overrides result in a deterioration of the PCRA’s risk prediction capacities.

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.

Study on Quantitative Risk Assessment of LGP Transportation in Road Tunnel

2011 ◽  
Vol 255-260 ◽  
pp. 4105-4109
Author(s):  
Yu Chun Zhang ◽  
Chuan He ◽  
Yong Fang ◽  
Xiao Qin Sun
Keyword(s):  
Risk Assessment ◽  
Quantitative Risk Assessment ◽  
Liquefied Petroleum Gas ◽  
Road Tunnel ◽  
Boiling Liquid ◽  
Flash Fire ◽  
Vapor Cloud ◽  
Property Loss ◽  
Serious Injury ◽  
The Impact

Based on the tunnel environment and the characteristic of flammability and explosion of liquefied petroleum gas (LGP), the leak of LPG tanker can induce heavy casualties and property loss in the tunnel. In order to study quantitative risk of LGP transportation in road tunnel, the data of 599 accidents and 659 accidental vehicles are collected. From these data, the proportion of LGP tanker accident in the total accident vehicles and million vehicles kilometer (MVK) tanker accident rates are obtained. By analyzing the leakage scene of LGP tanker, the possible accident types of the LGP transportation were analyzed, such as boiling liquid expanding vapor explosion (BLEVE), vapor cloud explosion (VCE), flash fire and jet fire, etc. The impact of leak time to various ranges of injury is studied in the condition of LGP continued leakage. The slight injury, serious injury and death radius of LGP leakage accidents are calculated in tanker loaded with different LGP quantity. In view of the accidental analysis, the countermeasures will be proposed to reduce the risk of LGP transportation in road tunnel.

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