CONSIDERATION OF DISRUPTIVE EVENTS FOR THE YUCCA MOUNTAIN SITE RECOMMENDATION REPORT

The United States Department of Energy (DOE) addresses features, events, and processes (FEPs) that could disrupt the performance of the potential repository at Yucca Mountain through a systematic identification and screening process. Four potentially disruptive events have been identified in the proposed DOE regulation 10 CFR Part 963 as requiring particular consideration in the Site Recommendation (SR): volcanism, seismicity, nuclear criticality, and human intrusion. Each of these events has been evaluated for the SR. Seismicity and nuclear criticality are unlikely to have adverse impacts on the longterm performance of the site. Consequences of volcanism and human intrusion are presented in terms of calculated annual dose rates to future humans living 20 km from the potential repository. Calculated mean dose rates are small, reaching approximately 0.2 mrem/yr at 50,000 years for igneous disruption and 0.008 mrem/yr at 1000 years for an human intrusion 100 years after repository closure.