An offshore nuclear power plant mounted on gravity-based structures and its seismic performance

Abstract

This paper proposes a new concept for an offshore nuclear power plant including its safety features. The design concept of the offshore nuclear power plant mounted on gravity-based structures (GBSs), which are widely used offshore structures, is proposed first. Based on the new concept, a large-scale land-based nuclear power plant model APR1400 with 1.4 GW electrical output is mounted on the GBS. A new total general arrangement (GA) and basic design principles that were used are described. Then, the safety features of the offshore nuclear power plant are discussed. A new emergency passive containment cooling system (EPCCS) and emergency passive reactor-vessel cooling system (EPRVCS) are proposed; their features of using seawater as coolant and safety features of against tsunamis, earthquakes, and marine collisions are also described. The proposed offshore nuclear power plant is safer than conventional land-based nuclear power plants and it has strong potential to provide great opportunities in nuclear power plant industries. Addition to the new design concept, dynamic behavior of GBS during earthquake implement with the consideration of soil-sea-structure interaction by ADINA finite element program. The analysis model is based on the SMART GBS type of ONPP. By changing of unit weight of GBS and friction coefficient between seabed and GBS as analysis variables, the dynamic response results is compared to clarify the acceleration response reduction effects at the GBS. A typical configuration of caisson-type GBS is used for analysis and three real earthquake records along with one harmonic excitation are imposed as base acceleration.