Fluid-structure interaction plays an important role in nuclear engineering design, where several numerical and experimental tests need to be performed on new tank design before getting into the production process. The design can be performed for fluid storage tanks that require knowledge of sloshing frequencies and hydrodynamic pressure distribution on the structure. These can be very useful for engineers and designers to define appropriate material properties and shell thickness of the structure to be resistant under seismic loading. Data presented in current tank seismic design codes such as Eurocode are based on simplified assumptions for the geometry and material tank properties. Fuel tanks may undergo different types of loading, including seismic loading, where the behavior of storage tanks includes material nonlinearities, which are caused by material yielding. The Arbitrary Lagrangian Eulerian formulation based on finite element analysis presented in the paper takes into account material properties of the structure as well as the complex geometry of the tank. The formulation uses a moving mesh with a mesh velocity defined through the structure motion. In this paper, we use different approaches to solve a fluid-structure coupling problem. The first one uses the full Navier-Stokes equation for the fluid with projection method, and the second approach uses potential flow theory. The problem consists of a sloshing deformable tank submitted to acceleration loading.