A risk assessment method based on DEMATEL-STPA and its application in safety risk evaluation of hydrogen refueling stations

Conducting STPA (System Theoretic Process Analysis) analysis for hydrogen refueling stations can identify potential safety hazards and risks in the refueling station system, and take measures to prevent and mitigate these risks, ensuring safe and reliable operation of the refueling station. This paper proposes an improved STPA method for risk analysis of hydrogen refueling stations. Specifically, this method aims to first determine the purpose of risk analysis for the refueling station system, analyzing the system-level losses, hazards, and constraints of the entire refueling station. Secondly, the control structure of the refueling station system is constructed, the system boundary is determined, and a system control structure diagram is built. Next, unsafe control actions (UCA) are identified based on control actions, and a quantitative analysis of unsafe control actions is conducted using DEMATEL, obtaining the occurrence probability of unsafe control actions in the hydrogen refueling station system. Finally, loss scenarios are identified, and causation analysis is conducted for unsafe control actions with higher occurrence probabilities, providing improvement measures and risk control recommendations. Through the improved STPA analysis, problems with the control structure, safety functions, and control and safety subsystems of the hydrogen refueling station system can be identified, the safety performance and potential problems of each subsystem can be understood, and effective measures can be proposed to reduce risks and ensure the safety of the refueling station system.