Coupled seismic analysis of a pressurized heavy water reactor building

The conventional approach for the design of various equipments is to use the applicable floor response spectra generated from the reactor building model wherein the equipments are not modelled along with the civil structure. However, for major heavy equipments like primary steam generators, primary heat transport pumps, pressurizer, calandria-end shield assembly etc. of a PHWR, this may not be adequate as these equipments affect the response of primary structure and vice versa. A coupled analysis has been carried out to get a more realistic picture of stresses at the equipment supports. Effects of coupling/decoupling these equipments with reactor building have been studied and the results have been compared