Published online by Cambridge University Press: 21 February 2011
We predict the transport of 14C from the proposed nuclear waste repository at Yucca Mountain using a porous medium model. Use of this model is justified if the Peclet number, which indicates equilibrium between gas in fractures and liquid in rock pores, is much less than unity. For the assumed release rates, maximum predicted concentrations of 14CO2 in rock near the ground surface are comparable to the USNRC limit for unrestricted areas. Furthermore, dilution near the ground surface as the 14CO2 enters the atmosphere will lower the concentrations by several orders of magnitude. Travel times from the repository to the surface are predicted to be hundreds to thousands of years. For a wide range of the parameters, the release rate from the source has negligible effect on the maximum concentrations at the ground surface.