Design-stage QRA for indoor vehicular hydrogen fueling systems

In recent years, high pressure gaseous hydrogen has become increasingly popular as a vehicle fuel. The National Fire Protection Association (NFPA) is one of several organizations developing codes and standards to ensure the safety of the vehicular hydrogen infrastructure. As part of code development activities, NFPA is exploring the use of Quantitative Risk Assessment (QRA) to help provide a technical basis for specific requirements in the Hydrogen Technologies Code (NFPA 2). The authors conducted the QRA activity to 1) provide screening-level insights into the fatality risk from code-compliant, indoor hydrogen fueling systems for NFPA 2 Chapter 10 (Gaseous Hydrogen Vehicle Fueling Facilities) and 2) identify gaps in QRA that must be resolved to enable more detailed, robust QRA analyses. This paper documents the results of this early-stage QRA activity and suggests several QRA improvements that would enable more widespread use of QRA for vehicular hydrogen applications.