Publications Details
Dual porosity models for solute transport at Yucca Mountain
A fractured porous medium is often modeled as a dual porosity system. The subsystems of fractures and matrix pores are assumed to provide two flow continuums. This is especially true when considering solute transport through such a system. Coupling terms are then required to enable the calculation of the exchange of solute between the two subsystems. The coupling terms for solute transport through a fractured medium are derived in this report. This report then investigates the need for the dual porosity models for solute transport. It is shown that the complexity of a dual porosity model is required in some cases to accurately represent the solute motion. However, it is also shown that some situations can be well represented by approximate single porosity models if certain criteria are met. A single porosity model allows the use of analytical solutions. Sample calculations are presented using parameter values representative of Yucca Mountain tuffs. These calculations show that a dual porosity model is not required to model solute transport at Yucca Mountain if the water fluxes are as low as currently believed. 39 refs., 10 figs., 2 tabs.