Parallel Distributed Seismic Analysis of an Assembled Nuclear Power Plant

An overview of the seismic simulation of nuclear power plants and reduction of parallel computation cost are discussed in this chapter. The safety requirement of a nuclear power plant is extremely high, enough to perform real experiments to evaluate the structural integrity of mechanical components. However, such experiments are performed on independent sets of components because the ability of experimental facilities is limited. Hence, a numerical simulation which can treat a whole assembled plant attracts more and more attention with the growing computational technologies. To simulate such complex assembled structures, hierarchical simulation strategy was introduced and implemented as a simulation framework. In hierarchical simulation strategy, large mechanical components such as pressure vessels and small ones such as pipes are loosely coupled because the displacement transferred from the small component to the large one approaches zero as the size difference increases. The computation cost for seismic simulation of a nuclear power plant is drastically reduced with this strategy. The balancing domain decomposition method is also investigated to reduce the computation cost of large mechanical components. Because the computation cost of balancing domain decomposition method depends much on the number of subdomains, a prediction curve for an optimal number of subdomains is introduced in this chapter. Numerical validation is performed with a component of an actual nuclear power plant.