Nuclear power plants are built in a variety of countries and regions all over the world. Some of these regions show seismic activity. Consequently, seismic excitation is an important factor to be considered in designing these plants. The article summarizes the basic principles of safe nuclear power plant design in seismically active regions. First, the safety concept underlying seismic design and the corresponding international safety requirements and guidelines are presented. Next, the analytical techniques and methods of computation are shown which can be used in designing for seismic events, and the. conservative elements existing in the entire chain of computation are outlined. The impacts of deconvolution and of dynamic soil structure interactions upon building design and building response spectra (floor response spectra, secondary spectra) are examined. Finally, damage to nuclear power plants observed as a consequence of real earthquakes is discussed together with the findings derived from such incidents.
