[en] Regulating high risks activities has always been an ambitious task as the regime shall both prevent and compensate the potential damage of such activities. It becomes even more complex with nuclear energy as radioactivity possesses this transboundary character which implies an international cooperation. The need for an appropriate framework for nuclear energy started to raise in the 60s, when States realise that the classic liability system was not relevant for that kind of activity. The Paris and Vienna conventions were subsequently adopted in order to fill this legal gap. Nonetheless, the real turning point remains the Chernobyl accident which resulted in a considerable number of new international instruments as 5 conventions were adopted in the fields of safety and emergency preparedness within a 11 years period: the Convention on Early Notification of a Nuclear Accident, the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, the Convention on Nuclear Safety, the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management and the Convention on Supplementary Compensation for Nuclear Damage. This catastrophe was also the occasion to identify and mitigate the shortcomings of the existing regime in undertaking a revision process through several supplementary protocols, the Joint Protocol Relating to the Application of the Vienna Convention and the Paris Convention, the Protocol to Amend the Vienna Convention on Civil Liability for Nuclear Damage. 25 years after Chernobyl, another tragic nuclear event occurred in Fukushima. Once again it challenged the efficiency of the existing international regime and raises the question as to whether international law represents a relevant solution to such accident. (author)