Office of Nuclear Regulatory Research

Seismic ground motion time series are critical parameters for the analysis and design of structures, systems, and components of nuclear power plants, and for some advanced seismic probabilistic risk assessments. Seismic time series will be increasingly used in evaluating advanced nuclear reactor designs, many of which involve interactions of innovative systems such as seismic base isolators and water pools that behave in the nonlinear regime during strong earthquakes. To adequately represent the design response spectra, the synthetic seismic ground motion time series must (1) meet the response spectrum matching criteria and (2) ensure the sufficiency of their power spectral density functions.

The Greedy Wavelet Method (GWM, https://doi.org/10.1016/j.nucengdes.2023.112384) was developed to meet a research need for hundreds of response-spectrally matched time series, which were used to estimate the uncertainties in in-structure response spectra due to uncertainties in input time series. The GWM algorithm is fast and stable, and its computational advantages over its predecessors show its high potential for analysis and design of nuclear power plants. This session will provide hands-on demonstration of the GWM and will show how it can help meet regulatory guidance.