Calculation of seismic performance of nuclear containment vessel structure under design base earthquake

Abstract

To study dynamic response of the nuclear containment vessel structure under the action of design basis earthquake and evaluate the seismic performance of structure, the elastic time history analysis of nuclear containment vessel structure is performed to determine the most unfavorable displacement and stress distribution. A 3D nuclear containment vessel structure was modelled in FE package tool ABAQUS to perform time analysis. The maximum displacement in X direction occurred at the top of the structure dome under the excitation of three different seismic records; the time at which the top response acceleration peak of the structure does not coincide with the time of the base input seismic wave peak, and it is mainly related to the relation between the period of natural vibration and the period of seismic waves; Under the different seismic waves’ excitation of 0.2 g peak acceleration, the tensile stress around the equipment hole and near connection between the bottom plate and the cylinder body is large, while the maximum tensile stress appears around the hole of the device. In the design of nuclear containment vessel structure, the displacement of the top should be controlled and the reinforcement ratio around equipment hole should be increased.