FINITE ELEMENT RELIABILITY ANALYSIS OF AP1000 STEEL CONTAINMENT UNDER INTERNAL PRESSURES

摘要

AP1000 has been introduced to China since 2007, which is the third generation nuclear power plant developed by Westinghouse. The failure probability assessment of the containment building is an essential element of the level 2 PSA studies of nuclear power plant. In this paper, a 3D finite element model of the AP1000 steel containment vessel is built using the general-purpose nonlinear finite element analysis program ABAQUS. The software platforms of ABAQUS and MATLAB are combined to conduct reliability analysis of the steel containment vessel based on Finite Element Reliability Method (FERM). The reliability indices and sensitivity indices of the steel containment vessel under internal pressures are obtained. The results show that the yielding stress has largest effect on the containment among four parameters, and the head, which should be paid more attention to, is more important than the cylinder. The procedure based on FERM costs very little time, which shows that FERM is an efficient way to conduct the reliability analysis on the nuclear structure.