A comprehensive review of techno-risk assessment of hydrogen storage and transportation systems: integrating performance, safety and uncertainty for large-scale deployment

The large-scale deployment of hydrogen is constrained by the lack of robust, validated quantitative risk assessment (QRA) frameworks tailored to its unique properties. This review critically evaluates established QRA methods, including fault tree, event tree, FMEA, and Bayesian approaches, for hydrogen storage and transportation systems such as compressed gas, liquid hydrogen, cryo-compressed, and material-based technologies. Significant shortcomings have been found in data availability for failure rates, likelihood of ignition, and consequences. Additionally, current safety procedures and standards such as NFPA 2, ASME, and CHMC1 do not account for the dynamic nature of the problem. One significant issue is the lack of a database of hydrogen-specific reliabilities, making predictions less accurate. In order to overcome these problems, a framework that incorporates physics models, probabilistic analysis, and Bayesian analysis is suggested. This framework will be superior compared to other existing QRA models that use compressed gaseous hydrogen, such as HyRAM, and incorporate physical properties of liquid hydrogen (LH 2 ), cryo-compressed and material-based hydrogen storage systems using a Bayesian Network. With the integration of FMEA, FTA, ETA, and HAZOP in the same probabilistic structure, this framework is able to adaptively assess risks based on increasing amounts of field data. This paper addresses some crucial research directions that need to be addressed for deploying hydrogen infrastructure safely