Site-Specific Seismic Ground Response Study for Nuclear Power Plants and Ports in Mumbai

Abstract

The importance of characterizing site-specific free-field surface motion of facilities of national and worldwide economic influence [like ports and nuclear power plants (NPPs)] is well-realized, especially in Mumbai, the most important commercial city in India, with 40% of its land reclaimed from the Arabian Sea. In the research reported in this paper, site-specific seismic hazard and one-dimensional (1D) equivalent linear ground response analysis (GRA) of important sites in Mumbai [Jawaharlal Nehru Port (JNPT), Mumbai Port, Bhabha Atomic Research Center (BARC), and Tarapur Atomic Power Station (TAPS)] are attempted. The seismicity of the research region is modeled through delineation of 31 fault sources with an earthquake database of the past 418 years (years 1594–2012). The epistemic uncertainty in hazard estimation is accounted by employing seven different ground motion prediction equations developed for worldwide shallow crustal intraplate environments. The probabilistic seismic hazard analysis (PSHA) at each site provided the design uniform hazard response spectra (UHRS) for 5% damping for three different levels of ground shaking. Using the recorded acceleration-time history of the 2001 Bhuj earthquake as a seed acceleogram, synthetic time histories are generated to match the design UHRSs obtained from PSHA for three different levels of bedrock motion. The site-specific ground response studies revealed that the JNPT site is susceptible to a higher seismic hazard than the other sites. The lowest seismic hazard is observed at the TAPS site, indicating safe siting of the nuclear power plant in the event of seismic excitation. The results of the research reported in this paper are recommended for further soil structure interaction and performance-based designing of systems, structures, and components (SSCs) of port and NPP facilities in Mumbai.