Concept for the reliability assessment of the containment of a PWR

A concept for the reliability assessment of the Containment of a PWR based on classical statistics is presented. The statistical nature of various external hazards such as earthquakes, external pressure waves, aircraft crashes, as well as internal load conditions such as the LOCA are discussed. The key problem, which is the establishment of the relation between the time-dependent frequency of occurrence of the hazards and their intensity, is discussed in light of their rare event property. For this reason the Poisson process is used as prediction model. The intensity distributions of the Fisher--Tippett type. Various failure modes such as fracture and the yield condition and their influence on the design are discussed. The work concludes with a numerical example in which the reliability of the steel hull of a sample containment structure under a large LOCA is calculated