ufd

1. LA-UR-17-24114
Philip Stauffer, Michelle Bourret, Peter Johnson, Shaoping Chu,
George Zyvoloski, Terry Miller
May 23, 2017
SFWST Campaign 2017 Working Group Meeting
Milestone: M4SF-17LA010303022
Thermal-Hydrologic-Chemical Modeling for
Field Tests
Experiments and Modeling to Support Field Test Design
LA-UR-17-24114

2. 2
LA-UR-17-24114
Session Schedule
March 2016
LA-UR-17-24114

3. 3
LA-UR-17-24114
FEHM Model Development for WIPP
Site Simulations
 Model Development Objectives
1. Build confidence in the safety case
2. Validate model results on simple experiments
3. Support the planning, design, and interpretation of laboratory
and field thermal tests
4. Optimize instrument placement and data collection in field
testing with sensitivity analysis
5. Reduce uncertainty in simulated performance under full scale repository
conditions
6. Code comparisons (FEHM, PFLOTRAN, TOUGH2, CODEBRIGHT)

4. 4
LA-UR-17-24114
Borehole mesh in support of small
diameter borehole field test
 Single 6” borehole embedded into
a 65 m3 box with dimensions of
3x3x7 m (7 m along the borehole)
 Four rows of nodes identified in red
delineate the possible smaller
diameter monitoring holes
 High resolution in the borehole
around the heater location

5. 5
LA-UR-17-24114
Borehole mesh in support of small
diameter borehole field test
 500 W heater result : Max Temperature = 130 C
 heater cylinder 8” long 4” diameter, sitting at 3.5 m into the borehole
Zoomed in 0.4 mFull 3 m mesh

6. 6
LA-UR-17-24114
Salt Pan Experiment : Understanding
Evaporation
 Presented at WM2017 Phoenix
March 2016

7. 7
LA-UR-17-24114
Salt Pan Experiment : Understanding
Evaporation
Change in weight of crushed salt
shows evaporation and
condensation of water from the air
 Increased evaporation when
relative humidity drops below
~40%

8. 8
LA-UR-17-24114
Pan Evaporation Experiment
• Model domain of salt cone
• No-flow boundaries on all sides
• 2-D Radially symmetric model of
mounded salt in a tray
• Time-variant boundary conditions of
temperature and relative humidity (mass
fraction of water in air)
• Water vapor pressure-lowering for pure
salt water in use with FEHM salt
capabilities

9. 9
LA-UR-17-24114
RoM Salt Evaporation Experiment
Model Results
 % mass change from initial are
tracked due to uncertainty in the
exact dimensions of the salt cone,
 length of the modeled record was
limited by simulation run-time and
numerical convergence difficulties
(showing 8 day simulation)
 Directionality of the modeled
changes tracks with measured
values
 FEHM-calculates Pwv lowering for
RoM salt = f(salt concentration,
capillary suction).

10. 10
LA-UR-17-24114
Salt pile mesh in support of full scale
waste canister field test
 Half-space mesh (1/2
canister along the length)
 Run-of-mine pile
surrounding the canister
 Rock damage zone
 Intact rock salt
 Air zone with evaporation to
remove moisture

11. 11
LA-UR-17-24114
Salt pile mesh in support of full scale
waste canister field test
Chimney effect
Red is upflow,
Blue is downflow

12. 12
LA-UR-17-24114
Salt pile mesh in support of full scale
waste canister field test
Porosity changes
Red is upflow,
Blue is downflow
Temperature Porosity

13. 13
LA-UR-17-24114
Future Work
Supporting field testing in salt through simulation:
• Continue refining simulations on the new
• Use simulation results to guide heater size and instrument placement
• Explore scenarios numerically before deploying into the field