The qualitative risk assessment of an electrolytic hydrogen generation system

•The qualitative risk of an electrolytic hydrogen generation system was assessed.•133 potential accident scenarios were analyzed with FMEA and HAZOP.•The risks of the system are acceptable because the risk levels are Category M or L.

A risk assessment for an electrolytic hydrogen generation system was carried out. The potential accident scenarios for the system were evaluated with a hazard and operability study (HAZOP) and failure mode effect analysis (FMEA). Brainstorming sessions were conducted to evaluate the possibility of each potential accident scenario. In the severity analysis for each potential accident scenario, the jet flame length was estimated based on an empirical formula using reference data. The blast pressure was mainly estimated by using the results of the reference. The risks of all potential hazards with and without the implementation of various safety measures were analyzed using risk matrices. It is clear that with the safety measures in place, the risk levels of all system hazards are acceptable.