Quantitative risk assessment of large-scale hydrogen refueling stations: A systematic numerical study

With the rapid development of hydrogen energy, the global demand for hydrogen refueling stations (HRSs) is escalating. Large-scale gaseous HRSs serve as pivotal regional hubs due to their high storage capacity and economies of scale, but substantial storage and complex systems inherently introduce elevated safety risks. This study conducts the first systematic quantitative risk assessment (QRA) of a large-scale gaseous HRS, specifically modeling a facility representing the world’s largest daily refueling capacity. By integrating event tree analysis and physical consequence models with detailed site-specific and meteorological data, potential accident scenarios are systematically evaluated. The occurrence frequencies are estimated, the severity of consequences (including dispersion, jet fires, and explosions) is assessed, and individual risk (IR) and societal risk (SR) are evaluated against international acceptability criteria. The results indicate a non-linear increase in accident consequence severity with storage capacity of HRS, manifested as an approximately 87.5% longer leak duration and a 23% larger 0.069 bar explosion impact zone compared to smaller stations. Both IR and SR analyses identify the high-pressure storage modules, tube trailer operating area, and dispenser area as the high-risk zones. The most severe accident consequences in these areas, such as lethal thermal radiation extending 25.4 m and explosion overpressure impacts reaching 104 m, can pose unacceptable risks to off-site third parties. Based on these findings, this study proposes targeted preventive measures and recommendations, providing a key quantitative reference for effectively reducing accident probability and consequence severity to ensure the safe planning, design, and protection of large-scale HRSs.