## 1 Introduction  
After Fukushima nuclear power plant accident, many efforts have been made to enhance the seismic capacity of nuclear power plants, especially for old nuclear power plants in operation, and to accommodate the beyond design basis earthquakes.  
In general, the seismic capacity of the nuclear power plants has been handled at the plant level, but recently the individual seismic capacity of the safety-related facility components such as control cabinet, emergency diesel generator, remote shutdown console, battery pack, spent fuel rack, and so on has become important in determining the seismic capacity of nuclear power plants. Especially enhancing the seismic capacity of the operating nuclear power plants, which have experienced various aging environments for a long service lifetime, is a critical issue in points of safety against potential beyond design basis earthquakes.  
There may be many ways to increase the seismic capacity of individual nuclear facility components [1, 2, 3], but applying the customized seismic isolators to individual nuclear components can be one of the effective approaches [4, 5].  
There are many types of seismic isolators such as friction pendulum system, rigid sliding bearing with damper, elastic sliding bearing with damper, laminated rubber bearing, etc. [6, 7, 8, 9]. Among them, the laminated rubber bearings (LRB) have been popularly developed in many countries for nuclear applications because they can support very heavy-weight and are very flexible in shear deformation against horizontal earthquakes. Due to these characteristics, LRBs have been generally developed for seismic isolation of buildings [10; 11; 12; 13; 14; 15; 16]. There are many studies on shaking table tests of LRBs for a building structure seismic isolation, but most of them are performed with the reduced scale LRBs [17; 18; 19; 20]. For this reason, there are very few studies of the shaking table tests for the full-scale LRBs.  
In previous studies, the small-sized LRBs with 10 kN vertical design load and 2.3 Hz seismic isolation frequency have been developed for individual nuclear component seismic isolation instead of entire building isolation. The developed LRB uses natural rubber and a lead plug is inserted in the center for damping. The design mechanical properties of LRB have been identified by the quasi-static tests [21].  
In this study, the shaking table tests of the full-scale LRBs developed in previous studies are carried out and their seismic isolation performance and dynamic characteristics are investigated through a well-established test matrix. The test conditions included in the test matrix are established to investigate (1) three levels of the seismic load, i.e., OBE (Operating Basis Earthquake), SSE (Safe Shutdown Earthquake), BDBE (Beyond Design Basis Earthquake), (2) damping function of the lead plugin continuous aftershock conditions, (3) consistent fabrication quality of small-sized LRBs, (4) extreme behavior of LRB, and (5) confirm the LRB design parameters. The used input motions in shaking table tests correspond to the typical floor response spectrum at 137 ft elevation of the nuclear power plant building structure, where the seismic isolation target components are expected to be located. To confirm the seismic isolation performance, three beam structures with different natural frequencies are installed both on the shaking table and the dummy mass supported by the LRBs, and their seismic responses of non-seismic isolation and seismic isolation cases are measured for comparison. Seismic analyses with two kinds of LRB models of the Bi-linear and the equivalent stiffness-damping are performed with the identified mechanical properties in previous studies and their results are compared with those of the tests to confirm the dynamic design characteristics.