Root cause analysis of a hydrogen storage explosion: A combined BowTie-Tripod approach applied to the Gangneung incident

Hydrogen storage is critical to the low-carbon transition, yet it introduces distinctive hazards associated with high-pressure vessels, cryogenic media and material degradation. This paper demonstrates a transparent application of an integrated BowTie–Tripod Beta framework, utilising the BowTieXP suite, to translate publicly available incident evidence into structured barrier-based and organisational learning. The 2019 Gangneung buffer-tank explosion was selected as a representative case from the Hydrogen Incident and Accident Database (HIAD). A BowTie diagram was first used to map the complete picture of the incident, highlighting six broad safety barriers that had failed, including the inadequacy or lack of evidence for detecting oxygen (O2) in H2, removal of O2, static controls, and the earthing and bonding system. Tripod Beta then traced each failed barrier back through its immediate causes, preconditions, and underlying causes, revealing systemic weaknesses in design verification, barrier maintenance, and process safety culture. Corrective and Preventive Actions (CAPAs) were formulated to address weaknesses identified in design reviews, barrier integrity monitoring, and competency management, through enhanced training and strict adherence to safety standards. In view of the exclusive reliance on secondary sources, the analysis explicitly grades the evidence strength for each barrier. It frames higher-level organisational contributors as plausible inferences rather than definitive findings. Although conclusions from this single case are not generalisable, the study provides a replicable reporting workflow and traceable CAPA development approach that can be adapted for other high-hazard hydrogen applications. Given the reliance on publicly available secondary sources, evidence-strength tags are used to communicate confidence and to frame the findings as structured hypotheses for verification and barrier design.