Nuclear Risk and Optimal Civil Liability of the Operator[Risque nucléaire civil et responsabilité optimale de l'exploitant]

The civil liabiliy of nuclear operators are regulated by two sets of international Conventions. In particular, strict liability, limited financial responsibility and the obligation of providing financial guaranties are imposed to the nuclear operator by the Paris Convention and the Vienna Convention. Then national legislations are free to increase the financial cap of responsibility fixed by the international regimes. First we present the main elements of these Conventions. Then we focus on the impact of a modification in the amount of responsibility of the nuclear operator on his risk mitigation policy and on his financial condition. In particular we show that an increase of the cap beyond a given level determined by the model gives the operator some incentives to lessen the investment in prevention, contrary to what is expected. Besides, the impact of the preventive activities done by the firm on its financial constraint depends on the sensitivity of the risk distribution to the variation of the prevention level: The risk mitigation activities must be discussed with respect to the severity of the incidents and/or to the size of the nuclear park.