................................................................................................................................... ii LIST OF FIGURES ....................................................................................................................... iv LIST OF TABLES......................................................................................................................... iv LIST OF ACRONYMS ................................................................................................................. iv 1.0 INTRODUCTION .................................................................................................................... 1 2.0 CONCEPTUAL MODEL OF SUBSURFACE FLOW AND TRANSPORT.......................... 2 3.0 MODEL FORMULATION ...................................................................................................... 3 3.1 Governing Equations ............................................................................................................ 3 4.0 SITE-SPECIFIC EXAMPLE.................................................................................................... 5 4.1 Geology................................................................................................................................. 7 4.2 Description of Nuclear Test .................................................................................................. 8 4.3 Boundary Conditions ............................................................................................................ 9 4.4 Input Data............................................................................................................................ 11 5.0 RESULTS OF SIMULATIONS............................................................................................. 13 5.1 Porous Media Simulations .................................................................................................. 13 5.1.1 Heterogeneous Permeability Field............................................................................... 16 5.1.2 Temperature Gradients................................................................................................. 27 5.1.3 Other Radionuclides..................................................................................................... 27 5.1.4 Fractures with 10-m Spacing ....................................................................................... 27 6.0 DISCUSSION......................................................................................................................... 32 6.1 Observations Specific to Rio Blanco .................................................................................. 32 6.2 General Observations Pertinent to all Sites ........................................................................ 33 7.0 CONCLUSIONS..................................................................................................................... 34 8.0 REFERENCES ....................................................................................................................... 34