Prevention and mitigation measures to ensure containment integrity

The consequences of severe reactor accidents depend greatly on containment safety features and containment performance in retaining radioactive material. In most severe accident sequences, the ability of the containment boundary to maintain its integrity is determined by two factors: (1) the magnitude of the loads: and (2) the response to those loads of the containment structure and the penetrations through the containment boundary. Severe accident phenomenology and consequences has been the subject of worldwide intense research for more than 20 years. In this paper, the main threats to the containment integrity are reviewed, the state of knowledge and remaining uncertainties are briefly described, and the links with the relevant Community research activities are made. Finally, areas in which further research may be needed are listed.