| Title: |
Development of an ERT‐Based Framework for Bentonite Buffers Monitoring From Laboratory Tests: 2. Quantitative Moisture Dynamics Estimation Model |
| Authors: |
Chen, Hang; Chou, Chunwei; Peruzzo, Luca; Borglin, Sharon; Chang, Chun; Bandai, Toshiyuki; Kneafsey, Timothy; Nakagawa, Seiji; Birkholzer, Jens; Zheng, Liange; Wu, Yuxin |
| Source: |
Journal of Geophysical Research: Solid Earth, vol 130, iss 8 |
| Publisher Information: |
eScholarship, University of California |
| Publication Year: |
2025 |
| Collection: |
University of California: eScholarship |
| Subject Terms: |
3707 Hydrology (for-2020); 37 Earth Sciences (for-2020); Generic health relevance (hrcs-hc); ERT; nuclear waste; moisture; EBS; 0402 Geochemistry (for); 0403 Geology (for); 0404 Geophysics (for); 3705 Geology (for-2020); 3706 Geophysics (for-2020) |
| Description: |
The long‐term containment of high‐level radioactive waste in geological disposal repositories relies on Engineered Barrier Systems (EBS), with bentonite clay emerging as a candidate material due to its unique properties. Understanding moisture dynamics within bentonite buffers is crucial for EBS performance, as it directly influences the material's swelling capacity, thermal and hydraulic conductivity, mechanical properties, and long‐term evolution under complex thermal‐hydrological‐mechanical (THM) processes. This study develops an advanced Electrical Resistivity Tomography (ERT)‐based framework to quantitatively monitor moisture dynamics under THM conditions. Our framework extends the Waxman‐Smits model to incorporate the coupled effects of temperature, water content, fluid chemistry, and mechanical changes on bentonite's electrical properties. Utilizing HotBENT‐Lab data from our companion paper, which includes electrical conductivity, CT density, and thermocouple measurements, this study offers a novel methodological framework bridging different scales of the model. Our results show that the extended model can estimate water content from ERT data, capturing spatial and temporal variations in moisture distribution within bentonite columns. However, the model tends to overestimate water content compared to CT density‐derived measurements. We address this discrepancy by incorporating a simplified swelling effect model, which improves agreement between ERT and CT density‐based water content estimates. We also discuss model limitations, including simplified treatment of swelling and micropore effects, and propose a conceptual framework for transitioning from laboratory to field applications, addressing challenges such as parameter scalability, field validation methods, and integration of diverse data sources. This ERT‐based framework can potentially advance real‐world moisture monitoring of bentonite‐based EBS in nuclear waste repositories. Plain Language Summary Safely containing high‐level radioactive ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
qt5x7067zw; https://escholarship.org/uc/item/5x7067zw; https://escholarship.org/content/qt5x7067zw/qt5x7067zw.pdf |
| DOI: |
10.1029/2024jb030799 |
| Availability: |
https://escholarship.org/uc/item/5x7067zw; https://escholarship.org/content/qt5x7067zw/qt5x7067zw.pdf; https://doi.org/10.1029/2024jb030799 |
| Rights: |
CC-BY |
| Accession Number: |
edsbas.67D70BAE |
| Database: |
BASE |