109. june 9 collaboration with clausthal germany on coupled thm modeling_rutqvist

1. Used Fuel Disposition Campaign
Collaboration with Clausthal/Germany on
coupled THM modeling
Jonny Rutqvist, Laura-Blanco Martin, Jens Birkholzer
Lawrence Berkeley National Laboratory
UFD WG Meeting in Las Vegas
International Session
June 8, 2016

2. Used
Fuel
Disposition
Salt Coupled THM Processes – TOUGH-FLAC
 Lux/Wolters solid salt constitutive model (creep, TM damage-induced permeability
(DZ), high pressure fluid filtration, sealing, heating)
 Crushed salt constitutive model (THM properties as a function of compaction and
solidification)
 Large-strain and deformable mesh
 Brine migration, evaporation, condensation, salt precipitation etc. (THMC)

3. Used
Fuel
Disposition
Date Presentation or Meeting Title 3
Based on same software
Use of different numerical schemes
TOUGH-FLAC
(Berkeley Lab)
Sequentially coupled flow-geomechanics simulators
TOUGH2 (fluid + thermal flow)
FLAC3D (geomechanics)
Can deal with large strains & creep processes
Material-specific constitutive relationships available
FLAC-TOUGH
(TU Clausthal)
Similarities
Main difference
Fixed-stress split
Undrained split
TOUGH-FLAC vs FLAC-TOUGH

4. Used
Fuel
Disposition
Date Presentation or Meeting Title 4
• LBNL expertise on multiphase flow and geomechanics with TOUGH-
FLAC complemented with Clausthal expertise on salt geomechanics
and constitutive models
• New improvements implemented in both TOUGH-FLAC and FLAC-
TOUGH and benchmarked against each other
• Continuous collaboration with weekly SKYPE conversations
• Collaboration results presented in journal (2) and conference (5)
presentations during 2014-2016..
1. Blanco-Martín L., Wolters R., Rutqvist J., Lux K.-H., Birkholzer J.T. Comparison of two
simulators to investigate thermal-hydraulic-mechanical processes related to nuclear waste
isolation in saliniferous formations. Computers and Geotechnics, 66, 219–229 (2015).
2. Blanco-Martín L., Wolters R., Rutqvist J., Lux K.-H., Birkholzer J.T. Thermal–hydraulic–
mechanical modeling of a large-scale heater test to investigate rock salt and crushed salt
behavior under repository conditions for heat-generating nuclear waste. Computers and
Geotechnics, 77, 120–133 (2016).
LBNL-Clausthal Collaboration

5. Used
Fuel
Disposition
Date Presentation or Meeting Title 5
Example: TSDE (Heater Test) Asse Mine
Code-to-code verification and validation against experimental data

6. Used
Fuel
Disposition
Date Presentation or Meeting Title 6
Concluding Remarks
• Mutually very beneficial collaboration resulted in great
progress in salt coupled THM modeling within a few years
• Further model improvements and benchmarking is planned
focusing on full THM coupling, including fluid migration