Quantitative Pipeline Risk Assessment and Maintenance Optimization

Author(s):  
Patrick L. Wickenhauser ◽  
David K. Playdon

The quantitative risk assessment tool was used to calculate the failure rates, failure consequences and risk levels along the pipeline. Safety risk was characterized by the individual risk ratio, which was defined as the maximum individual risk associated with a given segment divided by the tolerable individual risk. Tolerable individual risk values were defined as a function of population density following the approach developed by MIACC and the UK HSE. Financial risk was expressed in dollars per km-year and included a dollar equivalent for public perception. The recommended maintenance plan was defined as the minimum cost option that achieved a tolerable safety risk. The first step in developing the plan was to identify all segments that do not meet tolerable risk criteria (i.e., segments with an individual risk ratio greater than 1). For each of these segments a number of potential maintenance scenarios that address the dominant failure threats were selected. A cost optimization analysis was then carried out in which the total expected cost associated with each maintenance option was calculated as the sum of implementing the option plus the corresponding financial risk component, amortized over the inspection interval. This analysis was used to identify the minimum cost alternative that meets the individual risk constraint. Outcomes of the analysis included the best maintenance option (e.g., inline inspection, hydrostatic test) and the optimal time interval for segment re-evaluation.

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 189
Author(s):  
Hee Jin Kim ◽  
Kyeong Min Jang ◽  
In Seok Yeo ◽  
Hwa Young Oh ◽  
Sun Il Kang ◽  
...  

Wind direction and speed are the most important factors that determine the degree of damage caused by a jet fire. In this study, the metal hose used to extract/supply fuel was identified as the component with the highest risk for a jet fire occurring at an aerospace facility. A risk assessment was performed to evaluate the individual risk of a jet fire from the metal hose according to the wind direction and speed. HSE failure data was applied for calculating the jet fire probability including metal hose failure, ignition frequency, and jet fire frequency. Which was 3.0 × 10−4. The individual risk of different fatality probabilities was calculated according to the wind rose data for the aerospace facility. The individual risk from jet fire in the aerospace facility was calculated with a maximum risk of 3.35 × 10−5 and a minimum risk of 1.49 × 10−6. The individual risk satisfied HSE ALARP criteria. In addition, firewalls, extinguishing systems, and an emergency shut off system were enhanced, and it was thought that the risk from jet fire could satisfy acceptable criteria.


Author(s):  
Maher Nessim ◽  
Shahani Kariyawasam

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.


Author(s):  
Patrick L. Wickenhauser ◽  
Brian T. Wagg ◽  
Fausto A. Barbuto

TransGas undertook a risk-ranking project for storage facilities as the first step in the process of evaluating the financial and life-safety risk associated with the eight storage facilities that they operate in Saskatchewan, Canada. Based on this analysis, two salt cavern storage facilities were selected for a quantitative risk assessment. The most cost-effective maintenance actions for each cavern were determined as follows: Fault trees were prepared for all of the identified failure scenarios. Several unique computer models were developed to predict the failure rates of the events identified in the fault trees and the consequences associated with both sub-surface and atmospheric releases from the storage facilities. Both life-safety and financial risk were considered in the analysis. For each of the caverns, a number of potential maintenance scenarios were selected that address the dominant failure causes. Life-safety risk was assessed first and compared to the TransGas tolerance. A cost optimization analysis was then carried out in which the total expected future cost associated with each maintenance option was amortized over the benefit period and compared to the total expected future cost associated with the current maintenance practice. The paper describes the risk analysis and cost optimization approach and provides case study examples of the caverns analyzed and the recommendations reached in each case.


2020 ◽  
Vol 41 (S1) ◽  
pp. s234-s234
Author(s):  
Kristin Sims ◽  
Roger Stienecker

Background: Since 1991, US tuberculosis (TB) rates have declined, including among health care personnel (HCP). Non–US born persons accounted for approximately two-thirds of cases. Serial TB testing has limitations in populations at low risk; it is expensive and labor intensive. Method: We moved a large hospital system from facility-level risk stratification to an individual risk model to guide TB screening based on Tuberculosis Screening, Testing, and Treatment of US Health Care Personnel: Recommendations from the National Tuberculosis Controllers Association and CDC, 2019. This process included individual TB risk assessment, symptom evaluation, TB testing for M. tuberculosis infection (by either IGRA or TST) for HCP without documented evidence of prior LTBI or TB disease, with an additional workup for TB disease for HCP with positive test results or symptoms compatible with TB disease. In addition, employees with specific job codes deemed high risk were required to undergo TB screening. Result: In 2018, this hospital system of ~10,000 employees screened 7,556 HCP for TB at a cost of $348,625. In 2019, the cost of the T Spot test increased from $45 to $100 and the cost of screening 5,754 HCP through October 31, 2019, was $543,057. In 2020, it is anticipated that 755 HCP will be screened, saving the hospital an estimated minimum of $467,557. The labor burden associated with employee health personnel will fall from ~629.66 hours to 62.91 hours. The labor burden associated with pulling HCPs from the bedside to be screened will be reduced from 629.66 hours to 62.91 hours as well. Conclusion: Adoption of the individual risk assessment model for TB screening based on Tuberculosis Screening, Testing, and Treatment of US Health Care Personnel: Recommendations from the National Tuberculosis Controllers Association and CDC, 2019 will greatly reduce financial and labor burdens in healthcare settings when implemented.Funding: NoneDisclosures: None


2020 ◽  
pp. 58-67
Author(s):  
Rafał Hubicki ◽  
Maria Richert ◽  
Piotr Łebkowski ◽  
Joanna Kulczycka ◽  
Asja Mrotzek-Bloess

Assessment and management of risk constitute the subject of many researches. Nevertheless, many more specific factors are applicable during the implementation of innovative technological projects. On the article identified risk factors, which have been supplemented, systematized and assigned to the individual risk categories. The risk assessment methods for R&D projects have been analysed, as well as the risk sheets have been developed for the R&D project through the use of dotProject application. Also shown that networking and clustering is a change for fruitful cooperation within difference EU projects, which create trust between business and sciences and reduce the risk.


1993 ◽  
Vol 56 (12) ◽  
pp. 1043-1050 ◽  
Author(s):  
JOAN B. ROSE ◽  
MARK D. SOBSEY

Human pathogenic viruses have been detected from approved shellfish harvesting waters based on the fecal coliform indicator. Until recently it was difficult to assess viral contamination and the potential impact on public health. Risk assessment is a valuable tool which can be used to estimate adverse effects associated with microbial hazards. This report describes the use of quantitative risk assessment for evaluating potential human health impacts associated with exposure to viral contamination of shellfish. The four fundamental steps used in a formal risk assessment are described within and include i) Hazard identification, ii) Dose-response determination, iii) Exposure assessment, and iv) Risk characterization. Dose-response models developed from human feeding studies were used to evaluate the risk of infection from contaminated shellfish. Of 58 pooled samples, 19% were found to be positive for viruses. Using an echovirus-12 probability model, the individual risk was determined for consumption of 60 g of raw shellfish. Individual risks ranged from 2.2 × 10−4 to 3.5 × 10−2. These data suggest that individuals consuming raw shellfish from approved waters in the United States may have on the average a 1 in 100 chance of becoming infected with an enteric virus. Using the rotavirus model which represents a more infectious virus, the risk rose to 5 in 10. The potential for use of a risk assessment approach for developing priorities and strategies for control of disease is immense. Epidemiological data have demonstrated the significance of shellfish-associated viral disease and, although limited, appropriate virus occurrence data are available. Additional information on virus occurrence and exposure is needed, and then scientific risk assessment can be used to better assure the safety of seafood.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Javier García-Abellán ◽  
Antonio Galiana ◽  
Marta Fernández-González ◽  
Nieves Gonzalo-Jiménez ◽  
Montserrat Ruiz-García ◽  
...  

Abstract Background Differentiating between persistent infection with intermittent viral shedding and reinfection with severe acute respiratory syndrome coronavirus 2 remains challenging. Although a small number of cases with genomic evidence of second infection have been reported, limited information exists on frequency and determinants of reinfection, time between infections, and duration of immunity after the primary infection. Case presentation We report a reinfection with severe acute respiratory syndrome coronavirus 2 in a 52-year-old caucasian male whose primary infection was diagnosed in May 2020, during the first wave of the pandemic in Spain, and the second occurred 8 months later, in January 2021. We present a complete dataset including results from real-time polymerase chain reaction, serology, and genome sequencing confirming reinfection with a different clade. Noteworthy was that the patient was immunocompetent but had multiple cardiometabolic comorbidities, including refractory arterial hypertension, that might increase the individual risk in coronavirus disease 2019. Conclusions This case of reinfection with severe acute respiratory syndrome coronavirus 2 occurring several months after the primary infection reports the longest time interval between reinfection and initial infection described to date. It raises concerns on the duration of protective immunity, suggesting that it may begin to wane in patients who acquired the initial infection during the first wave of the pandemic. The potential contributing role of arterial hypertension and cardiometabolic comorbidities as risk factors for reinfection deserves investigation.


2015 ◽  
Vol 26 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Michael A. Guillemette ◽  
Rui Yao ◽  
Russell N. James

A variety of risk assessment questionnaires are used within the financial planning profession to assess client risk preferences. Evidence indicates that the average person overweighs losses relative to an arbitrary reference point. This paper evaluated risk assessment questions on how well they correlate with monetary loss aversion. Twenty-nine Western Texas residents between the ages of 27 and 56 participated in experimental research and filled out several risk assessment questionnaires. Two weeks later their levels of loss aversion were measured using monetary gain and loss scenarios. The individual risk assessment questions were placed into three categories: expected utility theory, prospect theory and self-assessment. Composite measures were created for within-group and between-group comparisons. Statistically significant correlations were found between monetary loss aversion and different composite measures. The results provide financial planners with a group of risk assessment questions that capture loss-averse preferences.


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