Seismic isolation technology has the potential to significantly reduce the overall risk posed by earthquake ground motions to nuclear power plants. A testing programme is an integral part of a seismic isolation project. Not only must the isolating devices be characterized for design purposes, but also validation of the analytical procedures used in design is required. Hybrid simulation is a testing technique which is a good candidate to experimentally assess the behaviour of an isolation system. The method combines the computation of the response of the isolated structure with the experimental determination of the behaviour of full-scale isolators under the demand imposed by the movement of ground and structure. This publication contributes to the assessment of the method as a tool for the design and safety demonstration of base-isolated nuclear facility buildings.