Study on yield limit of steel containment under external pressure considering initial defects

Abstract

The main objective of floating nuclear power plants (FNPP) is an emerging technology product formed by applying land small-scale nuclear power plant technology to the marine field. The containment structure studied in this article plays a great role in protecting the safety of FNPP’s nuclear power system. When exploring the safety performance of the containment structure under accident conditions, it is necessary to analyze and study the external pressure yield limit of the containment. This study provides a reference basis for the static buckling limit calculation of spherical shell structures similar to steel safety shells. The article adopts a geometric initial defect analysis method based on buckling mode to consider the initial defects of the model and explores the external pressure yield limit of the safety shell through the arc length method. The research results analyzed that the external pressure yield limit of the containment vessel decreased by about 30% under the influence of initial defects and pointed out the weak structural parts of the containment vessel in the buckling analysis.