Vibration Reduction Mechanism and NPPs Seismic Safety of TMD Shield Building for AP1000 NPPs

Without additional mass, the tuned mass damping (TMD) shield building for AP1000 Nuclear Power Plants (NPPs) was achieved easily by changing the stiffness and damper between parts of shield building. Meanwhile, the new TMD structure combined the structural features of the shield building with TMD technology. The optimal model for the new structure was built and the optimal stiffness and damper of TMD bearing were given on the dynamic characters of the shield building and its parts. The vibration mitigation mechanism and reduction effect were clearly stated by using base shear force transfer function. By comparing with the seismic responses of the traditional model and the base isolation model, the influence factors of the new TMD structure, such as the mechanism of TMD bearing, the gravity liquid tank mass, and the earthquake waves under different sites were studied. The new TMD structure is tested to satisfy the NPPs seismic safety requirements, stable reduction efficiency, anti-seismic robust characteristics and adaptive site.