A preliminary total-system performance assessment for the potential repository site Yucca Mountain

We present a preliminary performance assessment of Yucca Mountain, Nevada, U.S.A., as a potential site for a radioactive-waste repository. Models and results are discussed for four basic categories of processes and events: groundwater flow and aqueous transport, gas flow and gaseous transport, human intrusion, and basaltic volcanism. Calculated releases of radioactivity to the accessible environment are compared with U.S. Environmental Protection Agency requirements. The preliminary results show releases from human intrusion and volcanisms to fall well below the regulatory limits, though not all aspects of those categories have yet been considered. Calculated releases for nominal gaseous transport (of 14CO2) are closest to the limits, indicating that models and data relating to gaseous releases may need to receive higher priority. (author) 15 figs., 33 refs