FRACTURE EVALUATION OF SURFACE CRACKS IN LIGHT WATER-REACTOR PRESSURE-VESSELS UNDER PRESSURIZED THERMAL-SHOCK LOADING

The evaluation of pressure vessel integrity affected by pressurized thermal shock (PTS) events caused by emergency cooling due to a small leak break is being addressed. Comprehensive numerical and experimental investigations were performed at MPA Stuttgart and the HDR plant. This paper describes numerical and experimental investigations with large-scale heavy section specimens with circumferential and semi-elliptical cracks. The whole range of material toughness relevant for RPV integrity studies was tested. A full-scale vessel test at the HDR plant is reported, too. The experimental results were evaluated for validation of the analytical and numerical methods. Results from these investigations contribute to resolving a generic issue in the area of reactor pressure vessel integrity.