Seismic Consequence Modeling for the Yucca Mountain Repository Project

The legislatively-mandated site for the U.S. repository for spent nuclear fuel and high level radioactive waste is located at Yucca Mountain, Nevada. The U.S. Department of Energy has suspended work to license the site, but the completed safety case offers insights into estimation and mitigation of seismic hazards for a nuclear waste repository. Repositories are unique among nuclear facilities because safety assessments must account for periods of 10,000 years or longer; consequently, large, low-probability seismic events, and the cumulative effects of multiple events, are considered. Characteristics of future seismicity were assessed using a site-specific seismic hazard analysis developed from regional seismic data. The hazard analysis provided the expected magnitude and recurrence frequency of future events, and was used to develop design basis ground motions for the preclosure safety analyses and postclosure performance assessment. In the postclosure analysis, seismicity plays a major role in the degradation and failure of subsurface components.