Italian experience in the development of safety criteria for nuclear power plants

Between 1981 and 1987 a significant effort was directed in Italy to the development of a standard design to be adopted as a reference for the new generation of nuclear power plants (NPPs) provided at that time by the National Energy Plan. Beyond the fact that the evolution of the political thought as well as public opinion after the Chernobyl accident have practically suspended any activity related to the construction and operation of NPPs in Italy, that commitment represented a unique experience. The National Energy Plan envisaged that the Italian PUN plant should have been developed, even within the framework of an imported general light water reactor technology, by the utilization of the Italian design capabilities existing in the Electric Generating Board, among the national architect-engineers and the main industrial suppliers. In accordance with an explicit provision of the plan, the Italian licensing body, the Directorate for Nuclear Safety and Health Protection (DISP) of the Comitato Nazionale per la Ricerca e per lo Sviluppo dell' Energia Nucleare e delle Energia Alternative (ENEA) had to follow the project in order to state in a timely manner the requirements to be implemented in the design. As a result of this activity, a set of general safety and radiological criteria has been issued. Specific examples of the criteria are presented in the paper. Even in the present stand-by situation of nuclear activities in Italy, the effort mentioned above should not be considered useless; in fact the safety criteria established for the PUN plant will represent the basis for any development in the future. In this perspective the general design criteria document should be obviously reviewed in the light of more recent developments in safety technology. In particular, the evaluation of the knowledge in the field of severe accidents and of the developing technology based on intrinsic safety concepts, which Italy presently is considering with interest, is discussed in the paper. (author)