Seismic isolation design analysis on pool-type LMFBR

A pool-type LMFBR is studied in Japan as one of the candidates of the future LMFBR, which has a large diameter main vessel (M/V). But in our country we have so severe regulations, that it is difficult to design a M/V without any seismic supports. So we have studied a seismic isolation design in which a M/V is supported by an isolation system in expectation that the seismic response acceleration of a M/V would become lower and that the seismic loads would be reduced. In this study a Mil/ and a building are modeled to beam elements with lumped masses respectively and connected by a non-linear spring which represents the isolation system. Then we have carried out the seismic response analysis and have investigated the feasibility of the isolation.