1. Hierarchical Modeling Linking to Science-Support Models EXAMPLE Hierarchical Modeling Linking to Science-Support Models Groundwater Modeling System RT3D and MT3DMS FRAMES-2.0 Workshop U.S. Nuclear Regulatory Commission Bethesda, Maryland November 15-16, 2007 Pacific Northwest National Laboratory Richland, Washington

2. 2 PurposePurpose Demonstrate Hierarchical Modeling by Linking to Science-Support Models Perform a 3-D Numerical RT3D Groundwater Simulation Perform a Semi-analytical Groundwater Simulation

3. 3 FRAMES and GMS GMSGMS is the most sophisticated/comprehensive groundwater modeling package, containing numerous numerical models and support features ONLY GROUNDWATER FRAMESFRAMES seamlessly links user-defined disparate models, databases, and modeling systems to transfer data

4. 4 MT3DMS and RT3D MT3DMS is a modular, 3-D, multi-species transport model for the simulation of advection, dispersion, and limited chemical reactions Zero- or first-order decay of individual chemicals (no chain formation) RT3D is essentially MT3DMS with significantly enhanced reaction capabilities Multi-species reactive transport with chain formation Complex reaction kinetics with linked reactions, parallel pathways, etc. Reaction kinetics for any chemical system of interest, including a mixture of mobile and immobile components

5. 5 FRAMES and GMS Linkage/Run Protocol Set up a calibrated problem within GMS Stand-alone application Generate a GMS Project file (*.gpr) and associated files No intent to duplicate GMS functionality within FRAMES Map GMS contaminant names to FRAMES contaminant names Identify boundary conditions that will change Automatically build all linkages and files Build the CSM Choose the GMS stand-alone calibrated run Identify output location Run models

6. 6 Discussion Topics Example Application of Hierarchical Modeling RT3D Area Source Simulation Semi-analytical Groundwater Simulation

7. 7 Example Application of Hierarchical Modeling

8. 8 RT3D Semi-analytical Model Compare Semi-analytical and Numerical modeling results

9. 9 Problem Description A source of Non-Aqueous Phase Liquid (NAPL) TCE, which is leaching into an aquifer. TCE degrades to DCE and VC No DCE or VC initially exists at the source TCE concentration emanating from the source simulates first-order loss over a vertical plane. Simulate the fate and transport of TCE, DCE, and VC to and within the Saturated Zone

10. 10 Top View of Source Area Anaerobic Reaction Zone Boundary (Layers 1-3) N 100 ft 50 m Aerobic Reaction Zone 1 2 Simulation Output Locations ◦ 50 ft ◦ 180 ft Source Term (1 layer) 1 2

11. 11

12. 12 A A’ A

13. 13 N 100 ft 50 m Hydraulic Head Contours Horizontal Conductivity Flow Vectors Source Term Horizontal Hydraulic Conductivity (ft/day) 100 35 20 10 5.0 1.0 0.5 0.1 1E-2 1E-3 1E-4 1E-5 0 Horizontal Hydraulic Conductivity (ft/d) 28 29 39

14. 14 Problem Summary Area source release to an aquifer Dispersivity (x, y, z: 20, 2, 0.2 ft) Kd (TCE, DCE, VC: 0.57, 0.25, 0.17 mL/g) Bulk Density (1.6 g/cm 3 ) Porosity (total and effective) (30%) Numerical grid Chain degradation (TCE → DCE → VC) Representative Source-term Values Time-varying source-term (i.e., aquifer) concentrations (see curve) Source-term dimensions (L, W, Th: 221.4, 700, 19.75 ft) Darcy velocity (317.6 cm/yr) Half Life: TCE, DCE, VC: 4.744 (RT3D), 10.7 (Source), 3.795, 9.489 yr Aquifer Downgradient output location: 50 ft, 180 ft Aquifer thickness (numerical grid) (59.75 ft) Darcy velocity: 317.6 cm/yr Water solubility: TCE, DCE, VC: 1100, 2250, 2670 mg/L Half Life (anaerobic zone): TCE, DCE, VC: 4.74, 3.795, 9.489 yr Half Life (aerobic zone): TCE, DCE, VC: 1.90, 3.795, 9.489 yr

15. 15 TCE DCE and VC TCE

16. 16 RT3D Application

17. 17 Select a GMS Project File (pre-calibrated RT3D model) 1.Under the Tools menu, choose GMSImport 2.Browse for the location of the Calibrated GMS Project File (*.gpr file). The user originally stored the file, so the user knows where it is located. 1 2

18. 18 Left Click on Chemicals to Map GMS Chemicals to FRAMES Chemicals 2 1 3 4

19. 19 RT3D and MT3DMS may require a Synchronization Operator for multiple constituents. Construct a CSM

20. 20 Choose Modules

21. 21 Constituent Database GeoReference Constituent Database and GeoReference Modules

22. 22 Source Term Synchronization Operator Source Term and Synchronization Operator Modules

23. 23 Aquifer Exposure Pathway Aquifer and Exposure Pathway Modules

24. 24 Input Data to Each Module

25. 25 Constituent Database GeoReference (just Save and Exit) Constituent Database And GeoReference Input

26. 26 Source in an Aquifer Input

27. 27 Source in an Aquifer Input

28. 28 RT3D User Input (OBS Option): ● Location of Output Results ● Duration of Simulation 21 1 1350

29. 29 Run Each Module Constituent Database GeoReference Module Source Term Synchronization Operator Aquifer

30. 30 Source in an Aquifer Source-term Output Results Time-varying Concentrations Emanating from the Source

31. 31 Synchronization Operator Module

32. 32 RT3D Output Results Time-varying Concentrations 50 ft from Source Row 13, Column 21, Layer 1

33. 33 RT3D Output Results Time-varying Concentrations 180 ft from Source Row 15, Column 23, Layer 1

34. 34 N 200 ft 100 m Concentration (mg/L) 50.0 0.005 1.0 0.1 0.05 10.0 5.0 0.01 0.5 100.0 TCE at 25 yr Horizontal Hydraulic Conductivity (ft/day) 100 35 20 10 5.0 1.0 0.5 0.1 1E-2 1E-3 1E-4 1E-5 0 Horizontal Hydraulic Conductivity (ft/d)

35. 35 N 200 ft 100 m Concentration (mg/L) 50.0 0.005 1.0 0.1 0.05 10.0 5.0 0.01 0.5 100.0 Water Table Vertical Exaggeration = 10X TCE at 25 Years (looking to the West at column 22) Horizontal Hydraulic Conductivity (ft/day) 100 35 20 10 5.0 1.0 0.5 0.1 1E-2 1E-3 1E-4 1E-5 0 Horizontal Hydraulic Conductivity (ft/d)

36. 36 Semi-analytical Aquifer Model Application

37. 37 Assumptions/ConstraintsAssumptions/Constraints Semi-analytical model assumes that the progeny travel at the same speed as the parent one average, linear, unidirectional, pore-water velocity that Dispersivities/Dispersion coefficients (in three dimensions) are spatially constant that all hydrogeochemical properties are spatially constant progeny formation based on Bateman’s equation

38. 38 Remove the Synchronization Operator Choose the MEPAS 5.0 Aquifer Module Save simulation with a different name Build the CSM with the Semi-analytical Model

39. 39

40. 40

41. 41 TCE Aquifer Modeling Results (at 50 ft = R13, C21, L1) RT3D Results Semi-analytical Results

42. 42 DCE Aquifer Modeling Results (at 50 ft = R13, C21, L1) RT3D Results Semi-analytical Results

43. 43 VC Aquifer Modeling Results (at 50 ft = R13, C21, L1) RT3D Results Semi-analytical Results

44. 44 TCE Aquifer Modeling Results (at 180 ft = R15, C23, L1) RT3D Results Semi-analytical Results

45. 45 DCE Aquifer Modeling Results (at 180 ft = R15, C23, L1) RT3D Results Semi-analytical Results

46. 46 VC Aquifer Modeling Results (at 180 ft = R15, C23, L1) RT3D Results Semi-analytical Results