Application of quantitative risk assessment for performance-based permitting of hydrogen fueling stations

Abstract

NFPA 2, Hydrogen Technologies Code, allows the use of risk-informed approaches to permitting hydrogen fueling installations, through the use of performance-based evaluations of specific hydrogen hazards. However, the hydrogen fueling industry in the United States has been reluctant to implement the performance-based option because the perception is that the required effort is cost prohibitive and there is no guarantee that the Authority Having Jurisdiction (AHJ) would accept the results. This report provides a methodology for implementing a performance-based design of an outdoor hydrogen refueling station that does not comply with specific prescriptive separation distances. Performance-based designs are a code-compliant alternative to meeting prescriptive requirements. Compliance is demonstrated by evaluating a compliant prescriptive-based refueling station design with a performance-based design approach using Quantitative Risk Assessment (QRA) methods and hydrogen risk tools. This template utilizes the Sandia-developed QRA tool, Hydrogen Risk Analysis Model (HyRAM), to calculate risk values when developing risk-equivalent designs. HyRAM combines reduced-order deterministic models that characterize hydrogen release and flame behavior with probabilistic risk models to quantify risk values. Each project is unique and this template is not intended to cover unique, site-specific characteristics. Instead, example content and a methodology are provided for a representative hydrogen refueling site which can be built upon for new hydrogen applications.