Prevention and management of NaTech risk triggered by seismic events, in Major-Hazard Industrial Plants

Industrial accidents triggered by natural events are defined in the international literature as NaTech events (Natural–Technological). These processes arise from the interaction between natural hazards and industrial systems, and may cause simultaneous damage to multiple components, leading to uncontrolled releases of hazardous substances. Such releases can produce chains of multiple events and domino effects, with severe consequences for people, the environment, and critical infrastructure. Among natural hazards, seismic events are recognised as one of the most significant triggers of NaTech disasters worldwide. Earthquakes can damage both structural and non-structural components of industrial facilities, causing roof collapse, loss of containment, fires, and explosions. These failures can occur not only within the perimeter of industrial sites but also along distribution and supply networks, amplifying the spatial extent of the accident and its potential consequences. In the Italian context, this issue is particularly relevant, where a relevant number of Major Hazard Industrial Plants (MHIPs) are located in regions exposed to high seismic hazard. The objective of the research is to provide a multidisciplinary, integrated and systematic methodology that can improve both the prevention and management of NaTech risk in industrial plants exposed to earthquakes. This methodology combines expertise from geology, geotechnics, civil engineering, chemical engineering and industrial safety, acknowledging the complexity of the problem. The novelty contribution of this research is the central role assigned to local seismic response studies, which serve as the basis of NaTech risk assessments and seismic resilience analyses, enabling the estimation of the recovery time in post-seismic scenarios. In contrast to conventional methodologies that rely predominantly on current regulations and basic seismic hazard maps, the study highlights the added value of assessing site-specific amplification effects. This integration enhances the reliability of NaTech risk assessments and establishes a robust and transferable methodological framework, well-suited for application to other MHIP sites situated in geologically complex environments.