# Presentation: 081206

## 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

## Purpose

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

## FRAMES and GMS

- _[GMS](slide4.xml)_ is the most sophisticated/comprehensive groundwater modeling package, containing numerous numerical models and support features
** ****ONLY GROUNDWATER**
- _[FRAMES](slide6.xml)_ seamlessly links user-defined disparate models, databases, and modeling systems to transfer data

## 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

## 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

## Discussion Topics

- Example Application of Hierarchical Modeling
- RT3D Area Source Simulation
- Semi-analytical Groundwater Simulation

## Example Applicationof Hierarchical Modeling

## Example Applicationof Hierarchical Modeling

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

## 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

## Top View of Source Area

**Anaerobic**
**Reaction**
**Zone**
**Boundary**
**(Layers 1-3)**

**Aerobic**
**Reaction**
**Zone**

**1**

**2**

## Slide 11

## A

**A**

**A’**

**A**

**A’**

## 28

**28**

**29**

**39**

## 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/cm3)
- 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

## TCE

**TCE**

**DCE and VC**

**TCE**

## RT3D Application

## Select a GMS Project File

**Select a GMS Project File**
- (pre-calibrated RT3D model)

- Under the Tools menu, choose GMSImport
- 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**

## Left Click on Chemicals to Map GMS Chemicals to FRAMES Chemicals

**2**

**1**

**3**

**4**

## Construct a CSM

- RT3D and MT3DMS may require a Synchronization Operator for multiple constituents.

**Construct a CSM**

## Choose Modules

## Constituent Database and GeoReference Modules

**Constituent**
**Database**

**GeoReference**

**Constituent Database and GeoReference Modules**

## Source Term and Synchronization Operator Modules

**Source**
**Term**

**Synchronization**
**Operator**

**Source Term and Synchronization Operator Modules**

## Aquifer and Exposure Pathway Modules

**Aquifer**

**Exposure**
**Pathway**

**Aquifer and Exposure Pathway Modules**

## Input Data to Each Module

## Constituent

**Constituent**
**Database**

**GeoReference**
- (just Save and Exit)

**Constituent**
**Database**
**And**
**GeoReference**
**Input**

## Source in an Aquifer

**Input**

## Source in an Aquifer

**Source in an Aquifer**
**Input**

## RT3D User Input

**(OBS Option):**
**●  ****Location of Output Results**
**●  ****Duration of Simulation**

## Run Each Module

- Constituent Database
- GeoReference Module
- Source Term
- Synchronization Operator
- Aquifer

## Source in an Aquifer

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

## Synchronization Operator Module

**Synchronization Operator Module**

## RT3D Output Results

**Time-varying Concentrations**
**50 ft from Source**
**Row 13, Column 21, Layer 1**

## RT3D Output Results

**Time-varying Concentrations**
**180 ft from Source**
**Row 15, Column 23, Layer 1**

## TCE at 25 yr

**TCE at 25 yr**

## TCE at 25 Years(looking to the West at column 22)

**Water Table**

**Vertical Exaggeration = 10X**

**TCE at 25 Years**(looking to the West at column 22)

**Notes:**
10X vertical scale exaggeration

## Semi-analytical Aquifer

**Model Application**

## Assumptions/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

## Build the CSM with the Semi-analytical Model

- • 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**

## Slide 39

## Slide 40

## TCE Aquifer Modeling Results

- (at 50 ft = R13, C21, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**

## DCE Aquifer Modeling Results

- (at 50 ft = R13, C21, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**

## VC Aquifer Modeling Results

- (at 50 ft = R13, C21, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**

## TCE Aquifer Modeling Results

- (at 180 ft = R15, C23, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**

## DCE Aquifer Modeling Results

- (at 180 ft = R15, C23, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**

## VC Aquifer Modeling Results

- (at 180 ft = R15, C23, L1)

**RT3D**
**Results**

**Semi-analytical**
**Results**