Comparative modelling of the coupled thermal–hydraulic-mechanical (THM) processes in a heated bentonite pellet column with hydration
- Swiss Federal Nuclear Safety Inspectorate (ENSI),Brugg (Switzerland)
- Federal Inst. for Geosciences and Natural Resources (BGR), Hanover (Germany)
- Canadian Nuclear Safety Commission (CNSC), Ottawa (Canada)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Helmholtz Centre for Environmental Research (UFZ), Leipzig (Germany)
- Chinese Academy of Sciences (CAS), Wuhan (China). State Key Lab. of Geomechanics and Geotechnical Engineering, Inst. of Rock and Soil Mechanics
- Korea Atomic Energy Research Inst.(KAERI), Daejeon (South Korea)
- Japan Atomic Energy Agency (JAEA), Tokyo (Japan)
- Center for Nuclear Waste Regulatory Analyses (CNWRA), Rockville, MD (United States)
- Nuclear Regulatory Commission (NRC), Rockville, MD (United States)
- Inst. for Radiological Protection and Nuclear Safety (IRSN), Paris (France)
- Univ. of Kiel (Germany). Inst. of Geosciences
- National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland)
For the deep geological disposal of high-level radioactive waste in argillaceous rocks, the heat production of the waste is an important driver for thermal–hydraulic-mechanical (THM)-coupled processes. These THM processes influence the properties and conditions of the near field that in many repository designs contains bentonite as a clay buffer. One task in the DECOVALEX-2015 (DEvelopment of COupled models and their VALidation against Experiments) project was the modelling of a heated bentonite column (Villar et al. in Long-term THM tests reports: THM cells for the HE-E test: update of results until February 2014. Deliverable-no: D2.2-7.3. CIEMAT Technical Report IEMAT/DMA/2G210/03/2014, 2014) in preparation for the in situ heater experiment HE-E at the underground rock laboratory Mont Terri. DECOVALEX is an international cooperative project that focuses on the development and validation of mathematical models for simulating such coupled processes associated with disposal in deep geological repositories. Eight modelling teams developed their own THM-coupled models for the bentonite column experiment, using six different simulation codes. Each of the teams individually calibrated the THM parameters for the bentonite material. The eight resulting parameter sets agree well and allow a satisfactory reproduction of the TH measurements by all models. The modelling results for the evolution of temperature and relative humidity over time at three sensors in the bentonite column are in good agreement between the teams and with the measured data. Also, changes of the temperature due to modifications of the insulation and the adjustment of the heating power during the course of the experiment are well reproduced. The models were thus able to reproduce the main physical processes of the experiment, both for vapour-dominated diffusion during the heating phase and combined liquid and vapour transport during a subsequent heating and hydration phase. Lastly, based on the parameter sets, the teams predict a penetration of the water infiltration front in the 48-cm column filled with bentonite pellets to a depth between 25 and 35 cm over the 15,000 h (i.e. over 20 months) of the hydration phase of the experiment.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1476621
- Journal Information:
- Environmental Earth Sciences, Vol. 77, Issue 3; ISSN 1866-6280
- Publisher:
- Springer-VerlagCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Modelling the Mont Terri HE-D experiment for the Thermal–Hydraulic–Mechanical response of a bedded argillaceous formation to heating
Investigation of Coupled Processes and Impact of High Temperature Limits in Argillite Rock: FY17 Progress. Predecisional Draft