Seismic Reliability Analysis Of Base-isolated Concrete Containment In Nuclear Power Plants

Nuclear power is an efficient, sustainable, environmental friendly and clean energy,and nuclear power generation is an important guarantee for China’s energy. However,nuclear power generation may also at the same time cause the human disaster. To furtherenhance the safety of nuclear power to ensure the healthy development of China’s nuclearenergy, we can consider using isolation technology. The isolation is a way extending thestructural natural period greatly and thus reducing the seismic response of superstructure.Currently, isolation technology has been widely used in the general building structure,but for the nuclear power plants of these important buildings, isolation technology isseldomly used, and research is relatively weak, so we still need to analyze the securityand reliability of the isolation of nuclear power plant during the earthquake.In this paper, the containment of a nuclear power plant is taken as an example in thefollowing researches. The three-dimensional finite element model with the isolationbearing is established, and then the seismic reliability analysis is carried out. The mainresearch work is as follows:1. Nuclear containment is a key part of nuclear power structure. This paper useslarge-scale finite element analysis software ANSYS to build base-isolated andnon-base-isolated nuclear containment model, and the rationality of the model is verifiedthrough some experiments and simple calculation. Finally, the dynamic characteristics,the response spectrum analysis as well as elastic time-history response of base-isolatedand non-base-isolated nuclear containment model has been done respectively.2. Base-isolated structure will show a significant non-proportional dampingcharacteristic, its influence on the structure increases with the increase of differences instructural damping and isolation damping. This paper uses a more perfect complex modesuperposition response spectrum method and general real mode superposition responsespectrum method to calculate the earthquake response respectively, and compare thedifference between non proportional damping and approximate decoupling model.3. Through the establishment of the3D finite element model, the probability ofconcrete cracking and concrete crushing as well as the probability of failure of theisolation layer of nuclear containment have been analyzed using Latin hypercubesampling techniques combined with the response spectrum analysis method.4. Seismic reliability analysis of nuclear containment has mainly been done in thefortification standard, however, this paper also calculates the maximum peak groundmotion which base-isolated and non-base-isolated nuclear containment can withstandthrough using the conservative determine failure margin analysis method provided by theEPRI report. And this report is extended to take into account the capacities and needs ofthe isolation device. In short, the reliability of the non-base-isolated and base-isolated nuclear containment is analyzed from the other side.