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Turkeltaub T, Weisbrod N, Zavarin M, Chang E, Kersting AB, Teutsch N, Roded S, Tran EL, Geller Y, Gerera Y, Klein-BenDavid O. Radionuclide transport in fractured chalk under abrupt changes in salinity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168636. [PMID: 37981163 DOI: 10.1016/j.scitotenv.2023.168636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023]
Abstract
Internationally, it has been agreed that geologic repositories for spent fuel and radioactive waste are considered the internationally agreed upon solution for intermediate and long-term disposal. In countries where traditional nuclear waste repository host rocks (e.g., clay, salt, granite) are not available, other low permeability lithologies must be studied. Here, chalk is considered to determine its viability for disposal. Despite chalk's low bulk permeability, it may contain fracture networks that can facilitate radionuclide transport. In arid areas, groundwater salinity may change seasonally due to the mixing between brackish groundwater and fresh meteoric water. Such salinity changes may impact the radionuclides' mobility. In this study, radioactive U(VI) and radionuclide simulant tracers (Sr, Ce and Re) were injected into a naturally fractured chalk core. The mobility of tracers was investigated under abrupt salinity variations. Two solutions were used: a low ionic strength (IS) artificial rainwater (ARW; IS ∼0.002) and a high IS artificial groundwater (AGW; IS ∼0.2). During the experiments, the tracers were added to ARW, then the carrier was changed to AGW, and vice versa. Ce was mobile only in colloidal form, while Re was transported as a conservative tracer. Both Re and Ce demonstrated no change in mobility due to salinity changes. In contrast, U and Sr showed increased mobility when AGW was introduced and decreased mobility when ARW was introduced into the core. These experimental results, supported by reactive transport modeling, suggest that saline groundwater solutions promote U and Sr release via ion-exchange and enhance their migration in fractured chalk. The study emphasizes the impact of salinity variations near spent fuel repositories and their possible impact on radionuclide mobility.
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Affiliation(s)
- Tuvia Turkeltaub
- The Zuckerburg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel.
| | - Noam Weisbrod
- The Zuckerburg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
| | - Mavrik Zavarin
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94550, USA
| | - Elliot Chang
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94550, USA
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94550, USA
| | - Nadya Teutsch
- Geological Survey of Israel, 32 Yeshayahu Leibowitz St., Jerusalem 9371234, Israel
| | - Sari Roded
- The Zuckerburg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
| | - Emily L Tran
- The Zuckerburg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel; Now at Shamir Research Institute, University of Haifa, Qatsrin 1290000, Israel
| | - Yehonatan Geller
- Geological and Environmental Science Department, Ben Gurion University of the Negev, Beersheva 8410501, Israel
| | - Yarden Gerera
- The Zuckerburg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
| | - Ofra Klein-BenDavid
- Nuclear Research Center of the Negev, Negev, P.O. Box 9001, Beersheva 8419001, Israel; Geological and Environmental Science Department, Ben Gurion University of the Negev, Beersheva 8410501, Israel
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Jia S, Dai Z, Zhou Z, Ling H, Yang Z, Qi L, Wang Z, Zhang X, Thanh HV, Soltanian MR. Upscaling dispersivity for conservative solute transport in naturally fractured media. WATER RESEARCH 2023; 235:119844. [PMID: 36931187 DOI: 10.1016/j.watres.2023.119844] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/14/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Physical heterogeneities are prevalent features of fracture systems and significantly impact transport processes in aquifers across different spatiotemporal scales. Upscaling solute transport parameter is an effective way of quantifying parameter variability in heterogeneous aquifers including fractured media. This paper develops conceptual models for upscaling conservative transport parameters in fracture media. The focus is on upscaling dispersivity. Lagrangian-based transport model (LBTM) for dispersivity upscaling are derived for the solute transport in two-dimensional fractures surrounded by an impermeable matrix. The LBTM is validated against the random walk particle tracking (RWPT) model, which enables highly efficient and accurate predictions of conservative solute transport. The results show that the derived scale-dependent analytical expressions are in excellent agreement with RWPT model results. In addition, LBTM results are also compared to experimental results from the observed breakthrough curve of a conservative solute transport through a single natural fracture within a granite core. Comparing results from the LBTM and transport experiment shows that LBTM based estimated dispersivity is 10.55% higher than the measured value. Errors introduced by the experiments, the conceptual assumptions in deriving models, and the heterogeneities of fracture apertures not fully sampled by measuring instruments are main factor for such discrepancy. The sensitivity analysis indicates that the longitudinal and transverse dispersivities are positively related to the integral scale and the variance of the log-fracture aperture. The longitudinal dispersivity is strongly contolled by the variance of the log-fracture aperture. The LBTM may be useful for directly predicting solute transports, requiring only the acquisition of fractured geostatistical data. This work provides a better understanding of transport processes in fractured media which ultimately control water quality across scales.
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Affiliation(s)
- Sida Jia
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China
| | - Zhenxue Dai
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China.
| | - Zhichao Zhou
- CNNC Key Laboratory on Geological Disposal of High-level Radioactive Waste, Beijing Research Institute of Uranium Geology, Beijing, China
| | - Hui Ling
- CNNC Key Laboratory on Geological Disposal of High-level Radioactive Waste, Beijing Research Institute of Uranium Geology, Beijing, China
| | - Zhijie Yang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China
| | - Linlin Qi
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China
| | - Zihao Wang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China
| | - Xiaoying Zhang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, China; College of Construction Engineering, Jilin University, Changchun, China.
| | - Hung Vo Thanh
- Laboratory for Computational Mechanics, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, Viet Nam; Faculty of Mechanical - Electrical and Computer Engineering, School of Technology, Van Lang University, Ho Chi Minh City, Viet Nam
| | - Mohamad Reza Soltanian
- Departments of Geosciences and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA
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Hu QH, Shi YZ, Gao X, Zhang L, Liang RP, Qiu JD. An alkali-resistant metal-organic framework as halogen bond donor for efficient and selective removing of ReO 4-/TcO 4. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:86815-86824. [PMID: 35794336 DOI: 10.1007/s11356-022-21870-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
99Tc is one of the most problematic nuclear fuel products due to its long half-life and high environmental mobility. Direct removal of TcO4- from the highly alkaline solution of nuclear fuel is a serious and challenging environmental issue. In this work, the first efficient synthetic approach introducing halogens into a two-dimensional metal-organic framework, named Mn-MOF, is established using MnCl2·4H2O coordinating with neutral nitrogen-donor ligand, showing ultrahigh stability in alkaline aqueous even under 1 M NaOH. The luxuriant Mn-Cl bonds and ordered hydrophobic pore channels enable the Mn-MOF to have an efficient adsorption capacity for ReO4- with a large capacity (403 mg g-1), which is higher than most MOF adsorbents. More importantly, the Mn-MOF shows an excellent selectivity toward ReO4- in high-density competitive anions, such as NO3- and SO42-. Moreover, the outstanding performance of Mn-MOF in removing ReO4- endowed it successfully separated ReO4- from the simulated Savannah River Site (SRS) high-level waste (HLW) stream with high removal of 66.84% at the phase ratio of 10. The adsorption mechanism is further demonstrated by FT-IR, XPS analysis, and DFT calculation, showing that the ReO4- can selectively interact with Mn-Cl bonds and imidazole groups, forming unique halogen bonds Cl-O-Re, and a series of hydrogen bonds, respectively. This work suggests a new approach to the removal of TcO4- from nuclear fuel.
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Affiliation(s)
- Qing-Hua Hu
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China
| | - Yu-Zhen Shi
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China
| | - Xin Gao
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China
| | - Li Zhang
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China
| | - Ru-Ping Liang
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China
| | - Jian-Ding Qiu
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, 330031, China.
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, China.
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Li Y, Guo N, Xian D, Zhou W, Shi Y, Wang J, Chen Y, Liu C. Bentonite colloids immobilization and release in quartz column and its influence on selenite migration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:152833. [PMID: 35007589 DOI: 10.1016/j.scitotenv.2021.152833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/08/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Immobilization and release of colloids are important for colloids-facilitated migrations, and in the safety assessment of geological disposal for high-level radioactive waste, the association between the immobilization and release process of the bentonite colloids with selenite migration has not been well revealed. In this work, the migration of bentonite colloids under different conditions is evaluated, and the effects of colloids immobilization and release on selenite migration are studied. In addition, the cases of in-migration (colloids are immobilized in the quartz sand, and then selenite migrates through the quartz sand with immobilized colloids) and co-migration (colloids bearing selenite are immobilized in the quartz sand) are investigated. The results show that in the systems containing 3.0 mM Mg2+, the mobility of the colloids is highly hindered and the colloids are immobilized in the quartz sand mainly by straining effect. The immobilization of bentonite colloids affects selenite migration differently according to the immobilization process (in-migration or co-migration). A more significant retardation effect is observed in the co-migration process than in-migration due to the additional inner-sphere complexed selenite in the co-migration. The immobilized colloids can be more easily released by alkaline DI-water (pH 11.0) than acidic one (pH 6.0) as a result of the more negative surface charges of the immobilized bentonite colloids. The average size of the released colloids is larger than the initial colloids at the same pH. Selenite is found to be released ahead of colloids in either in- or co-migration process, and part of selenite is discovered migrating with released colloids in co-migration process. Since colloids immobilization and release would influence radionuclides migration, further research about colloids immobilization and release with broad range of pH and ionic strength in the host rock and its influence on the migration of other radionuclides are needed.
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Affiliation(s)
- Yao Li
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Ning Guo
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Dongfan Xian
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Wanqiang Zhou
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Yanling Shi
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Jingyi Wang
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Yawen Chen
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Chunli Liu
- Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
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Tran E, Zavrin M, Kersting AB, Klein-BenDavid O, Teutsch N, Weisbrod N. Colloid-facilitated transport of 238Pu, 233U and 137Cs through fractured chalk: Laboratory experiments, modelling, and implications for nuclear waste disposal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143818. [PMID: 33246722 DOI: 10.1016/j.scitotenv.2020.143818] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
The influence of montmorillonite colloids on the mobility of 238Pu, 233U and 137Cs through a chalk fracture was investigated to assess the transport potential for radioactive waste. Radioisotopes of each element, along with the conservative tracer tritium, were injected in the presence and absence of montmorillonite colloids into a naturally fractured chalk core. In parallel, batch experiments were conducted to obtain experimental sorption coefficients (Kd, mL/g) for both montmorillonite colloids and the chalk fracture material. Breakthrough curves were modelled to determine diffusivity and sorption of each radionuclide to the chalk and the colloids under advective conditions. Uranium sorbed sparingly to chalk (log Kd = 0.7 ± 0.2) in batch sorption experiments. 233U(VI) breakthrough was controlled primarily by the matrix diffusion and sorption to chalk (15 and 25% recovery with and without colloids, respectively). Cesium, in contrast, sorbed strongly to both the montmorillonite colloids and chalk (batch log Kd = 3.2 ± 0.01 and 3.9 ± 0.01, respectively). The high affinity to chalk and low colloid concentrations overwhelmed any colloidal Cs transport, resulting in very low 137Cs breakthrough (1.1-5.5% mass recovery). Batch and fracture transport results, and the associated modelling revealed that Pu migrates both as Pu (IV) sorbed to montmorillonite colloids and as dissolved Pu(V) (7% recovery). Transport experiments revealed differences in Pu(IV) and Pu(V) transport behavior that could not be quantified in simple batch experiments but are critical to effectively predict transport behavior of redox-sensitive radionuclides. Finally, a brackish groundwater solution was injected after completion of the fracture flow experiments and resulted in remobilization and recovery of 2.2% of the total sorbed radionuclides which remained in the core from previous experiments. In general, our study demonstrates consistency in sorption behavior between batch and advective fracture transport. The results suggest that colloid-facilitated radionuclide transport will enhance radionuclide migration in fractured chalk for those radionuclides with exceedingly high affinity for colloids.
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Affiliation(s)
- Emily Tran
- Zuckerburg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
| | - Mavrik Zavrin
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94550, USA
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94550, USA
| | - Ofra Klein-BenDavid
- Nuclear Research Center of the Negev, Negev, P.O. Box 9001, Beersheva 8419001, Israel; Geological and Environmental Science Department, Ben Gurion University of the Negev, Beersheva 8410501, Israel
| | - Nadya Teutsch
- Geological Survey of Israel, 32 Yeshayahu Leibowitz St., Jerusalem 9371234, Israel
| | - Noam Weisbrod
- Zuckerburg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel.
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Tran E, Reimus P, Klein-BenDavid O, Teutsch N, Zavarin M, Kersting AB, Weisbrod N. Mobility of Radionuclides in Fractured Carbonate Rocks: Lessons from a Field-Scale Transport Experiment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11249-11257. [PMID: 32786561 PMCID: PMC7498145 DOI: 10.1021/acs.est.0c03008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Current research on radionuclide disposal is mostly conducted in granite, clay, saltstone, or volcanic tuff formations. These rock types are not always available to host a geological repository in every nuclear waste-generating country, but carbonate rocks may serve as a potential alternative. To assess their feasibility, a forced gradient cross-borehole tracer experiment was conducted in a saturated fractured chalk formation. The mobility of stable Sr and Cs (as analogs for their radioactive counterparts), Ce (an actinide analog), Re (a Tc analog), bentonite particles, and fluorescent dye tracers through the flow path was analyzed. The migration of each of these radionuclide analogs (RAs) was shown to be dependent upon their chemical speciation in solution, their interactions with bentonite, and their sorption potential to the chalk rock matrix. The brackish groundwater resulted in flocculation and immobilization of most particulate RAs. Nevertheless, the high permeability of the fracture system allowed for fast overall transport times of all aqueous RAs investigated. This study suggests that the geochemical properties of carbonate rocks may provide suitable conditions for certain types of radionuclide storage (in particular, brackish, high-porosity, and low-permeability chalks). Nevertheless, careful consideration should be given to high-permeability fracture networks that may result in high radionuclide mobility.
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Affiliation(s)
- Emily
L. Tran
- Zuckerberg
Institute for Water Research, Jacob Blaustein Institutes for Desert
Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
| | - Paul Reimus
- Los
Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Ofra Klein-BenDavid
- Nuclear
Research Center of the Negev, Negev,
P.O. Box 9001, Beersheva 8419001, Israel
- Geological
and Environmental Science Department, Ben
Gurion University of the Negev, Beersheva 8410501, Israel
| | - Nadya Teutsch
- Geological
Survey of Israel, 32 Yeshayahu Leibowitz Street, Jerusalem 9371234, Israel
| | - Mavrik Zavarin
- Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Annie B. Kersting
- Lawrence
Livermore National Laboratory, Livermore, California 94550, United States
| | - Noam Weisbrod
- Zuckerberg
Institute for Water Research, Jacob Blaustein Institutes for Desert
Research, Ben Gurion University of the Negev, Midreshet Ben Gurion 8499000, Israel
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