Seismic fragility analysis of nuclear containment structure under chloride-induced reinforcing steel corrosion conditions

Abstract

Chloride-induced corrosion of reinforcing steel is one of the critical degradation factors influence the life cycle performance of the containment structure. Therefore, it is of great significance to study the safety performance of containment structure under chloride-induced reinforcing steel corrosion condition. This study presents fragility evaluation of the containment structure under chloride-induced reinforcing steel corrosion condition. Nonlinear time history analysis of the containment structure under different reinforcing steel corrosion conditions is carried out considering various uncertainties including uncertainty in material strength, record to record uncertainty and uncertainty in corrosion parameters. Roof drift under different ground motion intensity levels and seismic fragility of the containment structure corresponding to different performance level with typical service life are analyzed. Results reveal that with the increase of the service life of the containment structure, the increasing rate for roof drift of the containment structure decreases, while the variability of roof drift of the containment structure changes slightly. Service life of the containment structure has different impacts on the fragility of the containment structure corresponding to different performance levels. With the increase of service life, the increasing rate for failure probability of containment structure increases.