Seismic considerations in the design of atomic power plants

A seismic design is one of the most important factors for the safety of nuclear power plants constructed in seismic areas. The various considerations in the design of atomic power plant structures and components to achieve high degree (near absolute) of safety during future probable earthquakes is described as follows: (a) determination of design earthquake parameters for SSE and OBE (b) fixing time history accelerograms and acceleration response spectra (c) mathematical modelling of the reactor building considering soil-structure interaction (d) deciding allowable stresses, damping factors and serviceability limits like drift, displacements and crack widths (e) tests for determining stiffness and damping characteristics of components in-situ before commissioning of plant. The main questions that arise under various items requiring further research investigations or development work are pointed out for discussion. (author)