In order to make risk-informed decisions when designing corrosion mitigation and remediation programs for lateral piping, consequence and likelihood of a failure (LoF) are required to estimate the risk. Within industry, lateral piping does not always have In-Line Inspection (ILI) or Direct Assessment (DA) data. As such, the LoF models for corrosion on uninspected lateral piping rely on a semi-quantitative historic-based approach. This approach leverages a historic failure rate and modification factors to provide a lateral-specific rate of failure (Rf). However, when lateral piping has been inspected, a quantitative assessment can be applied to evaluate LoF. Based on a sample assessment on laterals with inspection data, the historic-based model showed more conservative LoF results. This conservatism could potentially drive unnecessary mitigation or remediation work on lateral piping where inspection data may not be available. This paper considers the use of calibration of the historic-based model with the inspection data available to provide a less conservative and more accurate assessment of the likelihood of failure for lateral piping without inspection data. Given the limitations and constraints in the data and models, it proposes the use of risk-informed decision making to develop the integrity management plan.
Key words: Risk-informed, lateral, piping, integrity management, historic-based, probability of failure, likelihood of failure