PROTECTION OF SHIPPING CASKS AGAINST TERRORISM : THE FRENCH APPROACH

The behavior of the casks used for the shipment of nuclear material must be assessed for a set of various normal and accidental situations. Though not explicitly required in the french regulations, the security of the casks must be studied in the case of terrorism (a large amount of explosive or an attack with a High Energy Density Device). As there is no legal framework allowing the competent authority to require that the transporters or designers of packages perform the appropriate assessments, the “Institut de Radioprotection et de Sûreté Nucléaire” (IRSN), in order to provide the Authority with elements of appreciation, has conducted analyses, for ten years. These analyses have been based on both experiments and numerical models for various kinds of casks and loads. These studies have been carried out with the concern that this approach be consistent with the one used for the facilities. In a first stage, this paper will briefly recall the approach used for assessing the consequences of sabotage on facilities. Then the paper will focus on the approach proposed by IRSN for assessing the behavior of shipping casks aggressed by terrorists in pointing out its consistency with the one used for the facilities. In a second stage, some examples concerning a cask used to ship PuO2 powder will be presented. Two kinds of aggression have been considered: a large amount of explosive and a conical shaped charge. Such studies involving tests and numerical models are intended to limit the need for costly experiments as these models can be extrapolated, in their range of validity, to casks having similar geometry or to different loads.