Evaluation of Analyses for Hydrogen Relevant Threats

This report was prepared by Kiefner and Associates, Inc. (Kiefner) as part of the research project titled “Investigate Damage Mechanisms for Hydrogen and Hydrogen/Natural Gas Blends to Determine Inspection Intervals for In-Line Inspection Tools” for the U.S. Department of Transportation (USDOT), Pipeline and Hazardous Materials Safety Administration (PHMSA), under Contract 693JK32310011POTA.

The objective of the Task 6 work was to provide an evaluation of the threat analysis characterization resulting from hydrogen gas service, as informed by the previously funded PHMSA Project #985. Task 6 work involved providing an evaluation of the threat analysis characterization resulting from hydrogen gas service, as informed by the previously funded PHMSA Project #985, to ultimately assess the threat analysis procedures compiled in the current project. The evaluation focused on the definition of threats in pipelines transporting hydrogen or hydrogen/natural gas blends, as detected by in-line inspection (ILI) as anomalies.

This evaluation was based on the analysis of previous and ongoing research, publicly available literature, and the evaluation of results from the analyses performed in Tasks 2 and 3 of this project, as well as the discussions included in this report. The recommendations regarding threat analysis for ILI tools are as follows:

• Determine the physical property/properties that the ILI tool aims to detect and size, and relate them to the threats defined in ASME B31.8S.
• Incorporate a standard method of reporting defects by ILI that maps to the threats defined in ASME B31.8S.
• Ensure ILI tool validation is performed with an appropriate field method for the threat requiring evaluation.
• Communicate validation results with the ILI vendor to grow the basis of knowledge, so that the industry can continue to improve over time.