UC Berkeley

Seismic isolation is utilized in both traditional and industrial structures for its ability to reduce structural responses while effectively protecting sensitive building contents. Although this mature technology has been studied extensively, there is limited research on its application to Nuclear Power Plants (NPPs). Studies have yet to address topics such as sensitivity of equipment and the effects of seismic isolation on floor response spectra (FRS) caused by high frequencies and the inclusion of vertical motion. This paper's studies investigate the relationship between structural response and isolator mechanics, ground motion sensitivity, and the effectiveness of various isolator types, especially nonlinear isolators. Overall trends are identified that provide insight into the interaction between the isolation system and the response at various levels of the NPP. By understanding these relationships and connections, a set of valid recommendations for the selection and design of isolation systems is provided. This work is pursued through analyzing the performance of an APR1400 plant considering regulatory guidelines and utilizing a variety of ground motions, isolator types, and isolator models.