The geologic media near Yucca mountain site consist of fractured welded
tuffs along with less fractured unwelded tuff. Numerical simulation of flow
and transport in such media poses a number of challenging problems, due
mainly to the heterogeneities and disorder in the media. In addition,
because of different dominant transport mechanisms in different regions of
the media, investigations need to be carried out at different time-scales.
“Time-marching” will pose a considerable problem in analyzing such
multi-scale transient problems. We develop a field-scale network model of
fractures and study transport of radionuclides through geologic media as a
function of disorder and correlated fracture-permeabilities.