2026 Thomas C. Kavanagh Memorial Structural Engineering Lecture

"Risk-informed, performance-based design of seismic isolation systems for nuclear power plants"

Abstract

Risk-informed pathways are being developed to support the design and licensing of next-generation nuclear power plants. This presentation describes one such pathway for implementing seismic base isolation. The methodology has evolved from a rigorous risk-based framework involving isolation-system-specific seismic displacement demand curves, fragility functions, and numerical integration of seismic risk, to a simplified closed-form procedure requiring displacement calculations only at an annual frequency of exceedance corresponding to the target performance goal (TPG). The resulting median displacement capacity, D50, provides the basis for prototype testing of seismic isolators and dampers.

The presentation begins with an overview of the nuclear regulatory framework relevant to risk-informed seismic design, followed by the derivation of displacement demand curves, development of isolation-system fragility functions, calculation of D50, and the associated prototype testing requirements for seismic isolation and energy dissipation devices.

Bio

Andrew Whittaker is a SUNY Distinguished Professor in the Department of Civil, Structural and Environmental Engineering at the University at Buffalo, and holds a Faculty Joint Appointment at the Idaho National Laboratory. He is a registered civil and structural engineer in the State of California. Whittaker’s undergraduate degree in civil engineering is from the University of Melbourne (1977) and his MS (1985) and PhD (1988) degrees are from the University of California, Berkeley. He is a Distinguished member of ASCE and a member of the US National Academy of Engineering.

Andrew Whittaker has contributed to the writing of ASCE standards, and ATC/FEMA guidelines for more than 30 years. He made significant contributions to the first generation of tools for performance-based earthquake engineering (FEMA 273, FEMA 274, FEMA 356, ASCE 41) and led the structural engineering team that developed the second generation of these tools (FEMA P-58). Whittaker served as Chair of the ASCE Nuclear Standards Committee from 2015 to 2026, and now co-chairs the ASCE 92 committee. He led Issue Team 11 in the current NEHRP cycle addressing risk targets for seismic isolation systems for buildings, with outcomes to inform ASCE/SEI 7-28.

Additional Information:

https://www.cee.psu.edu/events/kavanagh/index.aspx