(54k) Performing Quantitative Risk Calculations for a Natural Gas Pipeline

Over the past several years, Quest Consultants Inc. has conducted quantitative risk analysis (QRA) and risk assessment studies for a range of pipelines in the United States and abroad. In most instances, the risk acceptance or tolerability criteria is defined by the individual risk (IR) to a person; often this risk is presented as location specific individual risk (LSIR). The LSIR is a measure of the risk to a person who is continuously at a specific location.

In recent years, there has been increasing dependence on the use of societal risk acceptance or tolerability criteria, including the risk associated with pipelines. Pipelines are often described as linear sources of risk, like highways and rail lines. The risk analysis methodology used to calculate the risk associated with fixed facilities (e.g., refineries and chemical plants) cannot be directly applied to linear risk sources.

This paper presents a risk calculation methodology that can be applied to linear risk sources and describes how the societal risk (in the form of F-N curves) can be calculated.