Conditional probabilities of post-release events for hazardous materials pipelines

Abstract

Pipelines are commonly considered a safe alternative for the transportation of hazardous materials. However, in case of failure, pipelines still pose major risks to the environment and to the population potentially exposed. The aim of the present work is to provide occurrence probabilities of the intermediate and final events following the accidental release of hazardous materials from pipelines. A collection of incidents and accidents occurred worldwide in connection with the use of onshore long-distance pipeline networks, has been gathered to make up a specific database for the analysis of incidents in pipelines. A qualitative and quantitative analysis of the data has allowed to develop detailed event trees for the different classes of hazardous materials, and to calculate the probability of occurrence of the final outcomes. The investigation has also aimed at identifying, for each type of release, the relationship between the final events and the causes of the pipeline failure. The results obtained represent a useful and needed starting point in Quantitative Risk Analysis of hazardous materials transportation via pipelines.Peer ReviewedPostprint (author's final draft

Analysis of crater formation in buried NG pipelines: A survey based on past accidents and evaluation of domino effect

“…10, it can be seen that the immediate ignition is not very likely, showing a probability of 0.344. Bubbico et al (2016) provide an average value of 0.341 for the immediate ignition probability of compressed gases (with the weights being the fraction of cases of catastrophic and full-bore ruptures releases), which matches the value just found correctly.…”

“…For releases when the cloud dispersion is almost certain (50 cases out of 90 characterized by the "no immediate ignition" option), a median delayed ignition probability of 50% is observed; furthermore, the probability of flame front acceleration is higher (80%). In contrast to the case of the immediate ignition probability, the obtained probabilities for delayed ignition and explosion based on the reported data are higher than those cited by Bubbico et al (2016); that is, 0.464 for delayed ignition and 0.641 for flame front acceleration. Table 3 reports the overall probabilities of occurrence of the possible final events after the release of NG.…”

Crater formation by the rupture of underground natural gas pipelines: A probabilistic-based model

“…Now, if two parallel pipelines whose diameters are in the last category (20-36 inches) are in the same ditch, they would be separated by at least 1 m and as much 14 m. Suppose this separation is about 7-8 m (as in the Rapid City accident), then the examples and the predicted width dimensions suggest that a domino effect would take place. For this scenario, a safety distance of about 10m M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT could be suggested like in Silva et al (2016) by using only an extension of the crater width; nevertheless, this scenario is likely to be followed by a jet fire (Bubbico et al, 2016), so further calculations that are outside of the scope of this paper should be implemented. For more details see Ramírez-Camacho et al (2015); Alileche et al (2015); Haklar (1997); Haklar & Dresnack (1999); Sklavounos & Rigas (2006); Mohsin et al (2014).…”

“…In the case of natural gas, the possible final events are Vapour Cloud Explosion (VCE), Flash Fire, and Jet Fire (Ramírez-Camacho et al, 2017), so the safety distance would be delimited by: the extension of the flame envelope (Flash Fire); the flame length and its direction (Jet Fire); or the overpressure associated with the explosion energy (VCE) (Alileche et al, 2015). Consequently, further analysis is required to estimate a safety distance as the approaches reported in Haklar (1997), Haklar & Dresnack (1999), Sklavounos & Rigas (2006), Mohsin et al (2014) show for Jet Fire scenarios, which are the most probable events (Bubbico et al, 2016).…”

Driving Mechanisms, Motion, and Mechanics of Screw Drive In-Pipe Robots: A Review

“…Therefore, pipelines are widely used for transporting fluids in various fields [1]. The fluid transported inside the pipeline will cause damage to its inner wall due to high temperature, high pressure, high flow rate, and corrosion [2,3]. Hazardous fluids may leak if the pipeline is damaged, which may cause a large number of casualties, serious property damage, and environmental pollution [4].…”