Use of base isolation and energy-absorbing restrainers for the seismic protection of a large power-plant component. Final report. [PWR

Abstract

Analysis of the seismic response of large components in power plants is complicated by interaction between the component and the structure. In large components such as the steam generator this interaction cannot be neglected in forming accurate estimates of the response. Further, the presence of cracks in the internal piping of some steam generators has led to their integrity under seismic action being questioned. The experimental program described herein was initiated by the Electric Power Research Institute of Palo Alto, California, to provide an experimental assessment of the influence of interaction on the seismic response of such a large component. The report describes the design and construction of the steam generator model and model of the primary structure in which it is mounted and the results of an extensive series of simulated ground motion tests carried out on the shaking table at the Earthquake Engineering Research Center of the University of California at Berkeley. In these tests the steam generator model was supported in a conventional manner and on a natural rubber isolation bearing. The interconnection of the model and structure involved the use of a variety of restrainers.