Transposition of the Defence in Depth Concept to Hazmat Transport to Mitigate Territorial Vulnerability

Abstract

Since the 60’s, the defence in depth concept has provided a key approach to formalize and improve nuclear safety in power plants. It consists of deploying technical and organizational barriers and lines of defence structured on five protection levels. Protection levels represent the safety goals related to the prevention and control of abnormal operations, the mitigation of severe accidents and the radiological consequences of significant external releases of radioactive materials. After the AZF disaster (21 September 2001) in Toulouse (France), the Parliamentary Enquiry of the French Government announced numerous recommendations to improve safety of industrial and technological activities and, among them, the use of the “defence in depth” concept. In the context of the redefinition of the French strategy for risk prevention, this article presents a methodology to transpose this concept to improve the Hazmat Transport risk prevention and, as a corollary of this principle, to mitigate the vulnerability of the territory. This methodology is based on the use of the key notions of defence in depth, like barriers and lines of defence, and on their organisation into five essential protection levels that represent safety goals to be reached, from the prevention and control of abnormal operations, the mitigation of severe accidents etc. to crisis management. This article investigates this transposition in the context of territorial vulnerability in France, taking into account the specificities of this country, that is the regulation, the socio-economical and environmental situations, as well as the organisation of the territory.