An examination of experimental programmes to assess the influence of material toughness on vessel integrity during PTS

Three extensive experimental and analytical programmes are underway at the HDR, the MPA and ORNL, whose aim is to investigate fracture mechanics phenomena parameters. The quantification of these parameters is important for a fuller assessment of the safety margins in the pressure boundary of a nuclear reactor system in the event of occurrence of a pressurized thermal shock (PTS) accident. The three programmes are reviewed and it is shown that between the three, a full range of material properties is adequately covered. (orig.)