Management of NaTech accidents in industrial facilities

A NaTech accident is a technological accident caused by a natural event, the consequences of which are likely to affect third parties or the environment. This article focuses on industrial facilities using hazardous substances, including those covered by the Seveso 3 Directive in Europe. Indeed, several major international industrial accidents caused by natural phenomena have demonstrated the vulnerability of certain facilities to this type of aggression. Although few in number, these accidents have confirmed the importance of analyzing this issue as one of industrial safety and sustainable regional development.

In Europe, for industrial facilities subject to the Seveso 3 directive, the identification and analysis of accident risks generated by natural causes is required, with explicit mention of earthquakes and floods. In France, the Environmental Code also calls for natural events to be taken into account in the major risk prevention process for classified facilities. This requirement is reflected in specific decrees on earthquakes and lightning. This article is not intended as a summary of the regulatory requirements on the NaTech subject, but rather as a technical description of the prevention approaches that can be envisaged for these risks. Some French regulatory requirements are nevertheless presented by way of illustration, notably in the first section, which introduces a few general points on the NaTech issue.

Generally speaking, NaTech accident prevention procedures are structured around three elements: characterization of the reference natural event at the industrial site, identification of accident sequences, and implementation of an appropriate technical and organizational strategy. This generic plan forms the structure of the three sections dealing with floods, earthquakes and lightning. These three natural hazards occupy an important place in the NaTech theme, and their specific features naturally lead to very different risk management strategies. A comparative analysis of these three hazards also illustrates the multiplicity of technical fields to be addressed in the context of NaTech risk.