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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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Deblonde GJP, Morrison K, Mattocks JA, Cotruvo JA, Zavarin M, Kersting AB. Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20830-20843. [PMID: 37897703 DOI: 10.1021/acs.est.3c06033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Minor actinides are major contributors to the long-term radiotoxicity of nuclear fuels and other radioactive wastes. In this context, understanding their interactions with natural chelators and minerals is key to evaluating their transport behavior in the environment. The lanmodulin family of metalloproteins is produced by ubiquitous bacteria and Methylorubrum extorquens lanmodulin (LanM) was recently identified as one of nature's most selective chelators for trivalent f-elements. Herein, we investigated the behavior of neptunium, americium, and curium in the presence of LanM, carbonate ions, and common minerals (calcite, montmorillonite, quartz, and kaolinite). We show that LanM's aqueous complexes with Am(III) and Cm(III) remain stable in carbonate-bicarbonate solutions. Furthermore, the sorption of Am(III) to these minerals is strongly impacted by LanM, while Np(V) sorption is not. With calcite, even a submicromolar concentration of LanM leads to a significant reduction in the Am(III) distribution coefficient (Kd, from >104 to ∼102 mL/g at pH 8.5), rendering it even more mobile than Np(V). Thus, LanM-type chelators can potentially increase the mobility of trivalent actinides and lanthanide fission products under environmentally relevant conditions. Monitoring biological chelators, including metalloproteins, and their biogenerators should therefore be considered during the evaluation of radioactive waste repository sites and the risk assessment of contaminated sites.
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Affiliation(s)
- Gauthier J-P Deblonde
- Physical and Life Sciences Directorate, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Keith Morrison
- Physical and Life Sciences Directorate, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Joseph A Mattocks
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mavrik Zavarin
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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Wu X, Hong Y, Chen Z, Zhang T, Ding Y, Chen Y, Lan M. Research on safety early warning of uranium tailings dam based on abnormal radioactive indexes of water leachate. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 262:107148. [PMID: 36921389 DOI: 10.1016/j.jenvrad.2023.107148] [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: 10/11/2022] [Revised: 02/22/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
The radioactive index value of the leachate of the uranium tailings dam is affected by the internal damage of the dam. Therefore, a way of using the deviation of the radioactive index concentration in the leachate to warn the instability of the dam is innovatively proposed in this paper. Firstly, the SSA-BP algorithm is used to predict and analyze the five groups of parameters U, Ra, ∑ α, ∑ β and Rn. Then, the deviation between the actual value and the predicted value is computed. Finally, an early warning is given based on the entropy weight extension decision-making model. The model is verified by the leachate environment monitoring data of a uranium tailings dam in southern China from 2016 to 2020, which shows that the model can effectively caution of the instability of the uranium tailings dam and provides a reference for the subsequent decommissioning management.
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Affiliation(s)
- Xianwei Wu
- School of Resources Environmental and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China; Hunan Province Engineering Technology Research Center of Uranium Tailings Treatment, Hengyang, 421001, China
| | - Yang Hong
- Hunan Province Engineering Technology Research Center of Uranium Tailings Treatment, Hengyang, 421001, China
| | - Zhangkai Chen
- School of Resources Environmental and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China
| | - Tiejun Zhang
- China Nuclear Industry 23 Construction co., LTD., Beijing, 101300, China
| | - Yue Ding
- College of Finance and Statistics, Hunan University, Changsha, 410000, Hunan, China
| | - Yifan Chen
- School of Resources Environmental and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China; Hunan Province Engineering Technology Research Center of Uranium Tailings Treatment, Hengyang, 421001, China.
| | - Ming Lan
- School of Resources Environmental and Safety Engineering, University of South China, Hengyang, 421001, Hunan, China; Hunan Province Engineering Technology Research Center of Uranium Tailings Treatment, Hengyang, 421001, China.
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Borgman O, Be'er A, Weisbrod N. Direct visualization of colloid transport over natural heterogeneous and artificial smooth rock surfaces. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 251:104067. [PMID: 36113262 DOI: 10.1016/j.jconhyd.2022.104067] [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: 03/11/2022] [Revised: 08/13/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
Colloid transport in fractured rock formations is an important process impacting the fate of pollutants in the subsurface. Despite intensive and outstanding research on their transport phenomena, the impact of small-scale surface heterogeneity on colloid behavior at the fracture scale remains difficult to assess. In particular, there is relatively little direct experimental evidence on the impact of natural fracture surface heterogeneity on colloid transport. To investigate this, we developed an experimental setup allowing the direct visualization of fluorescent colloid transport in a flow cell containing a natural chalk rock sample while simultaneously monitoring effluent colloid concentrations. We used samples containing both a natural fracture surface and an artificially made smooth surface from the same chalk core. We characterized the roughness and chemical composition of both surface types and numerically calculated each surface's velocity field. From the experiments, we obtained direct images of colloid transport over the surfaces, from which we calculated their dispersion coefficients and quantified the residual deposition of colloids on the rock surface. We also measured the colloid breakthrough curves by collecting eluent samples from the flow cell outlet. The natural fracture surface exhibited larger physical and chemical heterogeneity than the smooth, artificially generated surface. The aperture variability across the natural surface led to preferential flow and colloid transport which was qualitatively apparent in the fluorescent images. The colloid transport patterns matched the calculated velocity fields well, directly linking the surface topography and aperture variation to colloid transport. Compared to the artificially made surface, the natural surface also showed higher dispersion coefficients, which corresponded to the colloids' earlier breakthrough from the flow cell. While we found differences between the elemental composition of the natural and artificially smooth surfaces, we could not observe their impact on the colloids' surface attachment and retention. The main novelty in this work is the coupling of direct colloid transport imaging, breakthrough curve measurements, and colloid surface deposition analyses, in a flow cell containing a natural carbonate rock sample. Our experimental setup can be used to further investigate the link between surface heterogeneity, both chemical and physical, and colloid transport and deposition in natural rock fractures.
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Affiliation(s)
- Oshri Borgman
- Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel; Univ Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, France.
| | - Avraham Be'er
- Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - 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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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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Kirishima A, Terasaki M, Miyakawa K, Okamoto Y, Akiyama D. Deep groundwater physicochemical components affecting actinide migration. CHEMOSPHERE 2022; 289:133181. [PMID: 34875295 DOI: 10.1016/j.chemosphere.2021.133181] [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: 07/30/2021] [Revised: 09/16/2021] [Accepted: 12/02/2021] [Indexed: 06/13/2023]
Abstract
To better understand the migration behavior of actinides in deep groundwater (GW), the interactions between doped tracers and deep GW components were investigated. La, Sm, Ho, and U tracers (10 or 100 ppb) were doped into sedimentary rock GW samples collected from 250 to 350 m deep boreholes in the experimental gallery of the Horonobe Underground Research Laboratory (URL), Hokkaido, Japan. To evaluate the effect of GW composition on the chemical speciation of actinides, the same tracers were doped into crystalline rock GW samples collected from 300 to 500 m deep boreholes in the experimental gallery at the Mizunami URL, Gifu Prefecture, Japan. Each GW sample was sequentially filtered through a micro-pore filter (0.2 μm) and ultrafilters with a 10 kDa nominal molecular weight limit. Next, the filtrate solutions were analyzed using inductively coupled plasma-mass spectrometry to determine the concentration of tracers retained in solution during each filtration step, and the used filters were analyzed using time-of-flight secondary ion mass spectrometry element mapping and X-ray absorption fine structure spectroscopy to determine the chemical species of the tracers trapped on each filter. It was determined that lanthanide migration was controlled by the amount of phosphates in the Horonobe GW. Therefore, it was expected that the solubility of minor actinides (MAs), which exhibit a similar chemical behavior to that of lanthanides, would be controlled by the formation of phosphates in sedimentary rock GW. Moreover, the data on the Mizunami GW indicated that a fraction of lanthanides and MAs formed hydroxides and/or hydroxocarbonates.
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Affiliation(s)
- Akira Kirishima
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 1-1 Katahira, 2-chome, Aoba-ku, Sendai, 980-8577, Japan.
| | - Mariko Terasaki
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 1-1 Katahira, 2-chome, Aoba-ku, Sendai, 980-8577, Japan; Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan
| | - Kazuya Miyakawa
- Horonobe Underground Research Center, Japan Atomic Energy Agency, Hokushin 432-2, Horonobe-cho, Hokkaido, 098-3224, Japan
| | - Yoshihiro Okamoto
- Materials Sciences Research Center, Japan Atomic Energy Agency, Kouto 1-1-1, Sayo-cho, Hyogo, 679-5148, Japan
| | - Daisuke Akiyama
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 1-1 Katahira, 2-chome, Aoba-ku, Sendai, 980-8577, Japan
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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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