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

(Part.3 : Validation of the Predictive Evaluation Method for Nonlinear Sloshing Wave Height and Impact Load Acting on Flat Roof)

Abstract

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. When the sloshing wave height is small, it can be approximated with a linear vibration model. However, when the sloshing wave height increases and the sloshing becomes nonlinear, it is necessary to evaluate the wave height using other methods such as numerical analysis. Although the evaluation of nonlinear sloshing wave height is important, there are few examples which quantitatively evaluate the wave height of nonlinear sloshing. This paper reports on the study result of the predictive evaluation method for nonlinear sloshing wave height and impact load acting on the flat roof applied to cylindrical tanks.