Study on the Predictive Evaluation Method of Nonlinear Sloshing Wave Height and Load of Cylindrical Tanks

The design basis ground motions have been revised to improve the seismic resistance of nuclear power plants. The reduction of seismic forces not only horizontally but also vertically has required more critical than in the past to ensure the seismic resistance of components. Notably, the design of a Sodium-Cooled Fast Reactor will require reducing the seismic forces applied to the components because of the components with thin wall thickness. To overcome this problem, the authors plan to introduce a seismic isolation system. However, the natural frequency of first order sloshing may be close to the response frequency of the Sodium-Cooled Fast Reactor with the seismic isolation system, and the sloshing wave height and the vertical load is expected to increase. The authors studied the setting method of sinusoidal wave excitation that generates sloshing loads equivalent to seismic wave excitation. This paper reports on an overview of this method.