Dynamic response of AP1000 water tank with internal ring baffles under earthquake loads

AP1000 is a standard design developed by Westinghouse for an advanced generation III+ nuclear power plant (NPP) utilizing passive features. Water storage tank of AP1000 plays an important role in cooling down the temperature of the inside of the NPP. However, the water sloshing and fluid-structure interaction effects of AP1000 water storage tank have an important influence on the dynamic response and safety of the nuclear power plant under strong ground motions. In this study, a fluid-structure interaction algorithm of finite element technique is employed to investigate the seismic response of water tank with internal baffles. Four schemes of ring baffle types are considered and the effects of various parameters, such as vertical baffle height, arrangements, and length of baffle on the dynamical response of shield building are investigated. It is indicated that the case 1 with vertical ring baffle near the bottom of tank is the best scheme for reducing dynamic response of shield building in AP1000.