Pipeline Transportation of Hazardous Materials ñ an Updated Quantitative Risk Assessment Methodology

Pipeline transportation of hazardous materials is increasing globally. Major accidents involving pipelines continue to happen. Guidance is provided from various sources for robust quantitative risk assessment (QRA) of pipelines. This paper describes new hazardous pipeline risk assessment capabilities implemented in the Safeti QRA software package. The methodology includes automatic case generation based on pipeline construction and operating parameters. The geometrical nature of pipelines and their resulting areas of surrounding risk are often long and narrow. Creation of Risk Contours around such geometries requires use of high aspect ratio grids. The calculation algorithm required for high aspect ratio hazard and risk zones such as those presented by pipelines is a challenge to traditional contour based risk assessment techniques. This paper describes a method for adaptive grid solution for long pipelines for optimal computation and result accuracy. The array of pipeline modelling also introduces time-varying fire simulation to account for the time-varying flow phenomenon typically experienced with pipeline breaches. In summary this paper demonstrates how these QRA methodology enhancements provide analysts with the tools necessary to perform rigorous analysis of pipeline risks in a consistent and efficient manner using validated models.