Abstract
The interest in the seismic performance of nuclear power plants has increased worldwide since the Fukushima Daiichi Nuclear Power Plant incident. In Korea, interest in the seismic safety of nuclear power plants has increased since the earthquake events in Gyeongju (2016) and Pohang (2017). In Korea, studies have been conducted to apply seismic isolation systems to ensure seismic safety while minimizing the design changes to nuclear power plants. Nuclear power plants with seismic isolation systems may have a higher seismic risk due to the failure of the piping system in the structure after a relatively large displacement. Therefore, it is essential to secure the seismic safety of pipes for the safe operation of nuclear power plants. The seismic safety of pipes is determined by seismic fragility analysis. Seismic fragility analysis requires many seismic response analyses because it is a statistical approach to various random variables. Typical numerical conditions affecting the seismic response analysis of pipes are the convergence conditions and mesh size in numerical analysis. This study examined the change in the seismic safety of piping according to the numerical conditions. The difference in the seismic response analysis results of the piping according to the mesh size was analyzed comparatively. In addition, the change in the seismic fragility curve of the piping according to the convergence conditions was investigated.
Highlights
Ensuring the seismic performance of nuclear power plants has attracted increased interest worldwide since the Fukushima nuclear incident
It is essential to ensure the seismic safety of these piping systems
A shake table test was conducted to analyze the seismic behavior of nuclear power plant piping
Summary
Ensuring the seismic performance of nuclear power plants has attracted increased interest worldwide since the Fukushima nuclear incident. Finite element analysis was performed to evaluate the seismic safety of the pipe system of the nuclear power plant [16,17]. The justification of seismic fragility analysis of crossover-piping was confirmed by applying a damage index based on the dissipation energy to express the actual failure quantitatively [20]. In the OECD (Organization for Economic Cooperation and Development)-NEA (Nuclear Energy Agency), the MECOS (Metallic Component Margins under High Seismic Load) benchmark, a round-robin test that performs finite element analysis based on test results, was conducted to identify an appropriate method to simulate dynamic and static nonlinear behavior for the piping of nuclear power plants accurately. Based on the detailed analytical model representing the experimental results, the difference in the seismic response analysis results of piping according to the mesh size was analyzed comparatively. The variability in the seismic fragility curve of the piping according to the convergence conditions was confirmed
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have