Assessment of Seismic Hazards at Yucca Mountain

摘要

During the preclosure time period (approximately 100 yr), the prospective geologic repository at Yucca Mountain must provide for public and worker radiological safety and retrievability of emplaced waste. During the postclosure period (10,000 yr), the repository must ensure that cumulative radionulclide releases to the accessible environment comply with EPA release limits. Substantially complete containment must be provided by the waste packages for 300-1000 yr. All of these functions must be maintained should a severe seismic event occur and must be achieved with reasonably available technology. The seismic phenomena of interest for the preclosure period are vibratory ground motion from a nearby earthquake or underground nuclear explosion (UNE), faulting beneath surface facilities that are important to safety, and faulting in underground areas of emplaced waste. For the postclosure period, earthquake ground motion, underground faulting, and seismically induced adverse changes in hydrologic conditions have been identified as the most important seismic phenomena to be characterized. The NNWSI Project Site Charcterization Plan describes a number of seismic parameters that are needed for repository design or performance assessment, along with tentative goals for each parameter. Key parameters, goals and current assessments, all subject to change as site characterization progresses, are summarized in this report. 4 refs. (ERA citation 13:035761)