Tritium Isotope Research Articles

Groundwater renewal time by environmental tritium isotopes as a tracer for sustainable water resource management

Studying groundwater renewal time is a valuable tool to deepen the comprehension of sustainable groundwater resources specific to arid regions. Tritium is a radioactive isotope of hydrogen often used as an environmental tracer to study groundwater renewal time. The present work reports groundwater renewal times by the environmental tracer tritium to understand sustainable water resources in arid regions. First, groundwater samples were collected from wells in northeastern arid regions of Saudi Arabia. Then, an electrolysis process was employed to significantly increase the tritium level from twenty-five to thirty times the original concentration. Subsequently, the enriched water was analyzed using a liquid scintillation counter under optimized measurement conditions to determine the tritium concentration precisely. Two internationally recognized tritium laboratories conducted independent assessments to validate the estimated tritium levels. The verified tritium concentration was then used to estimate the groundwater renewal time using the Morgenstern and Pimenta curves. The results suggest that most of the monitored wells in the surveyed areas are more than a century old. Conversely, a few monitoring wells exhibit renewal times of several hundred years and may be considered nonrenewable water sources. These studies help to understand the geochemical characteristics of arid regions to ensure the sustainable management and protection of groundwater resources.

Proton permeation and selective separation of hydrogen isotopes through fullerene nanocages (X12Y12): A DFT insights

To resolve the problem of mobile electrolytes for the permeation of hydrogen isotopes in fuel cells, we have studied herein heteronuclear fullerene nanocages (Al12N12, Al12P12, B12N12, and B12P12) for the separation and permeation of hydrogen isotopes. The separation and permeation of fullerene nanocages for hydrogen isotopes are studied at ωB97XD functional of DFT along with 6–31g (d,p) pople basis set. Zero-point energy (ZPE) is calculated for Protium (H+) and its heavier isotopes including deuterium (D+) and tritium (T+). The Arrhenius equation is employed to calculate the selectivity of protium to deuterium (H+/D+) and deuterium to tritium (H+/T+) isotopes. The selectivity is calculated by using the zero-point energy difference (ZPE) of protium (H+) to its heavier isotopes. The proposed fullerene nanocages estimated better selectivity for proton isotopes. The phosphide-based nanocages (Al12P12, B12P12) provide superior selectivity values of H+/D+ and H+/T+ compared to nitrogen-based nanocages (Al12N12, B12N12). This study provides insights into separation pathways for proton isotopes through nanocages for many industrial applications in the energy sector.

The effect of deuterium on defect production in irradiated tungsten

For fusion test reactors and power plants, one significant concern is the retention of hydrogen isotopes in the wall materials. The build-up of the radioactive and scarce fuel isotope tritium is of special concern, but knowing the retention of the other isotopes, such as deuterium, is also important. Deuterium is known to affect the mechanical properties of the wall material and most experiments are carried out on deuterium retention as it is safer to use than tritium. In addition to affecting the mechanical properties of the wall material, deuterium retention has been observed to affect the defect accumulation in the material. In this study, we investigate the phenomena and mechanisms responsible for the greater defect accumulation observed in tungsten when deuterium is present during irradiation. This is achieved computationally, utilizing molecular dynamics simulations and appropriate analysis tools. We found that deuterium will affect both the primary defect production as well as the recombination rate of defects in irradiated tungsten.

Теоретический анализ качества излучения и относительной биологической эффективности трития

Introduction 1. Tritium and reference radiation 1.1 Tritium isotope and its energy spectrum 1.2 Reference radiation 2. Methods for determining the quality of radiation and RBE 2.1 Radiation quality in microdosimetry 2.2 RBE by the number of DNA double-strand breaks 2.3 RBE by fraction of secondary low-energy electrons 3. Analysis of calculations of radiation quality and tritium RBE 3.1 Estimation of tritium emission quality factors 3.2 Evaluation of the RBE of tritium radiation during its action on DNA 3.3 Estimation of the RBE of tritium from the fraction of secondary low-energy electrons 3.4 Quality factors and RBE of tritium with respect to reference emissions Conclusion

Thermal simulations on a spinning rotor gauge to improve systematic uncertainties for viscosity measurements

Experimental values for the viscosity of the radioactive hydrogen isotope tritium (T2) are currently unavailable in literature. The value of this material property over a wide temperature range is of interest for applications in the field of fusion, neutrino physics, as well as to test ab initio calculations. To measure the viscosity of tritium, a measurement setup has been built utilizing a spinning rotor gauge inside a Dewar. Temperature control is of high importance to produce accurate and precise values. To ensure high quality measurement results, prior to the tritium measurements, thermal simulations are done on measurements with protium and deuterium inside the sample gas volume of the spinning rotor gauge.

Groundwater Age and Origin and Its Relation with Anthropogenic and Climatic Factors

Groundwater plays a major role in addressing the worldwide problem of water scarcity and food security. With a growing population and increasing urbanization, there is a rising demand for groundwater to meet agricultural and domestic water needs. A variety of advanced approaches are necessary to sustain groundwater management. This study investigated the age and origin of groundwater, as well as its relationship with anthropogenic and climatic factors. Stable isotopes were used, namely oxygen-18 (18O) and deuterium (2H) for the estimation of groundwater origin and radioactive isotopes of Tritium (3H) for the estimation of its age. The investigation of stable isotopes revealed that the aquifer is predominantly influenced by river water, with a minor contribution from rainwater. Furthermore, the analysis of radioactive isotopes revealed that the groundwater age ranges from 5 to 50 years old in most areas. Older groundwater is predominantly found in urban areas, while younger groundwater is present in agricultural and woodland regions. However, the presence of “old” water in the upper groundwater layers in urban areas is attributed to over-abstraction and limited natural recharge. The primary climatic factor that governs the age and origin of groundwater is rainfall upstream of the study area, which directly contributes to the river flows. The rainfall is high in the east but, due to urbanization, recharge is decreased. Consequently, old and river recharge groundwater is found in this area. These observations underscore the unsustainable and alarming use of groundwater in urban areas.

Groundwater Vulnerability Mapping Using the Susceptibility Index (SI) Method and Tritium Isotopes: A Case Study of the Gharb Aquifer in Northwestern Morocco

The Gharb aquifer plays a critical role as a source of drinking water and irrigation in Morocco. However, rapid economic growth and increased use of chemical fertilizers have led to groundwater pollution and land degradation. To address this issue, a vulnerability assessment was conducted using the Susceptibility Index (SI) method. Five parameters including depth to groundwater, effective recharge, slope, soil type, and land use/land cover were considered to evaluate groundwater vulnerability. The vulnerability assessment revealed index values ranging from 31 to 160. The study area was categorized into three zones of relative vulnerability (low, moderate, and high). Spatial analysis demonstrated significant spatial heterogeneity, with moderate vulnerability observed in areas characterized by shallow groundwater and composed primarily of sandstones in the northwest and southwest regions. In the entire study area, the low, medium, and high vulnerability zones covered 3%, 70%, and 26% (101 km2, 2725 km2, and 986 km2), respectively. Furthermore, Tritium isotope analysis and nitrate content were selected and applied as pollution markers to confirm and validate the obtained vulnerability map. The Tritium (3H) content in groundwater reveals a correlation with an R2 value of 0.86 with the degree of vulnerability, while the nitrate concentration in the aquifer’s groundwater showed a correlation with an R2 value of 0.55.

The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology

The Río Loa is a perennial river that crosses the Atacama Desert. A basin-wide survey enables for the first time, the hydrologic regime origin, persistence and processes to be identified. Perennial baseflow in the Ríos Loa and Salado largely originates from intra-arc aquifers which are poorly known. However, the data indicate that despite flood flow being largely confined to the summer (DJF) season, sufficient storage exists in these aquifers to maintain year-round stream flow from high-altitude, across the Atacama Desert to the coast. The intra-arc aquifers of the Western Cordillera receive recharge from time-variable precipitation infiltration and time-invariant lithospheric inputs. Lithospheric inputs potentially include slab/mantle dehydration, upper crustal melt devolatilization and/or thermally induced upflow of deeply penetrating meteoric water through buried evaporites or carbonates. Downstream, aquifers in the Pre-Andean basins variably interact with surface water, depending on location, river stage and time of year, but they do not supply significant additional sources of baseflow. Hydrochemical processes include those related to volcanic activity, soil carbonate generation, silicate weathering, CO2 degassing and calcite precipitation. Solutes undergo concentration by evaporation, gypsum dissolution, and are further affected by localized NO3, and SO4 inputs and mixing with saline waters. Stable isotopes reveal subcatchment specific precipitation and evaporation, whilst carbon and tritium isotopes are used to analyze recharge sources and processes in the intra-arc aquifers and downstream mixing.

Developing a conceptual model of groundwater – Surface water interactions in a drought sensitive lowland catchment using multi-proxy data

Frequencies and intensities of droughts have increased due to climate change, providing an urgent impetus to improve understanding of ecohydrological fluxes in drought-sensitive areas where water and food security are threatened. We used a multi-proxy approach for assessing the effects of landuse and catchment properties on recharge and groundwater – surface water interactions during a prolonged drought starting in summer 2018 in a 66 km2 lowland, mixed landuse catchment (Demnitzer Mill Creek, Germany). We used water table monitoring, water stable isotopes, tritium isotopes, hydrogeochemical tracers, streamflow observations and geophysical investigations to characterise the spatial and temporal patterns of groundwater recharge in a shallow, unconfined aquifer system. Long-term groundwater levels showed a declining trend since 2011, which accelerated after 2018 resulting in increasingly intermittent streamflow. Geophysical surveys and groundwater monitoring indicated that shallow water tables (typically < 3 m deep) in low to moderate permeability surficial deposits are generally recharged during winter, leading to higher groundwater – surface water connectivity in riparian alluvial aquifers, which is the first order control on streamflow generation. This was supported by similar geochemical characteristics of groundwater and streamflow. Water stable isotopes indicated a high damping in groundwater with a bias towards winter precipitation and direct recharge. Groundwater age estimates using tritium showed high uncertainty but indicated that shallow groundwater was < 10 years old and generally similar to streamflow. Such multi-proxy approaches help understand changes in groundwater recharge and stream-aquifer interactions during droughts and contribute to the development of sustainable land and water management strategies for groundwater systems that are sensitive to climate change.

Identification of groundwater hydrogeochemistry and the hydraulic connections of aquifers in a complex coal mine

It is important to understand the changes in the chemical composition and connectivity of each aquifer in the arid-semi-arid riverine mines under the driving force of coal mining and to establish a rapid identification of water sources in the riverine mines, which is important for the protection of groundwater resources and safe production in the study area. By analyzing the numerical characteristics of conventional elements, cluster analysis and the deuterium–oxygen and tritium isotopes of different aquifers, the groundwater chemical characteristics and hydraulic connections of each aquifer were determined. Three identification charts (Piper and Durov identification charts of conventional hydrochemical components and deuterium–tritium isotope identification charts) were established to enable the rapid identification of each aquifer water source. The results showed that the main recharge source of groundwater in the study area was atmospheric precipitation. There was a significant indigenous connection between the Quaternary aquifer and the Zhiluo Formation aquifer but a limited indigenous connection between the Zhiluo Formation aquifer and the Yan'an Formation aquifer, creating local groundwater systems that altered the local groundwater circulation patterns, driven by coal mining. Three identification charts were established to determine the water inrush sources and propose targeted solutions for water inrush from different aquifers in the Shendong mining area based on the differences in hydrochemical ion characteristics as well as deuterium–oxygen and tritium isotopes.

Using Tritium Isotope in Groundwater to Estimate the Reservoir Capacity at Erbil, Northern Iraq

Tritium is a radioactive isotope of hydrogen in water molecule can be applied in tracer studies to estimate water residence time. The tritium values of the groundwater in Erbil and the reservoir's capacity were the main subjects of this investigation. Three sub-basins, including, Kapran (720 km2), Central (1315 km2), and Bashtapa (625 km2) constructs Erbil City's groundwater basin. 27 groundwater samples from three sub-basins were taken for oxygen-18, tritium analysis and measurement of electrical conductivity. Tritium values divided the groundwater reservoirs into three possible groups: pre-bomb groundwaters that has ages older than 70 years due to lower tritium values, contaminated groundwater and mixture between young and old groundwaters. It is adequate to suppose that there were several substantial subsurface retention reservoirs in Dashty-Hawler basin. For instance, if two wells from the Kapan sub-basin were used as a point of reference, well No. 1 in Kalak region would have a tritium value of 1.7 ± 0.72 TU having groundwater that was approximately 16.2 years old. In contrast, the well No. 6 at Grd-Jutyar has a lower tritium value equal to 0.72 ± 0.68 TU indicating a greater residence time of 31.6 years. These two wells have differing reservoir sizes, and well No. 6 has a longer retention basin to store groundwater than well No. 1 According to these findings, younger groundwater and smaller retention basins were indicated by greater tritium levels, whereas older groundwater and larger retention basins were noted by lower tritium levels.

Computational investigation of isotopic effect in H2@X12N12 and H2O@X12N12 (X = B and Al) molecules

In this work, we reported isotopic effect in H2@X12N12 and H2O@X12N12 (X = B and Al) molecules at LC-ωPBE/6-311 G(d,p) level of theory. Zero-point energies values (ZPEs) of H2, H2O, H2@X12N12 and H2O@X12N12 molecules were calculated. Isotopes influenced the excess energies attained by molecules due to compression. The changes in ZPE of H2@X12N12 and H2O@X12N12 and those isotopic molecules intensely surpass those of the H2 and H2O molecules, subsequent in the great deuterium and tritium isotope effects. The excess of compression energy (Δ ɛ) obtained by the molecule under compression was sensibly, about 5.00–2.60 (X = B) and 1.48–2.63 (X = Al) kcal/mol. Larger kH/kD and kH/kT values were found in the presence of X = B than X = Al. These outcomes were recommended as a probe for analysis molecular compression of enzymatic positions; they may be significant for exploring extremely great experimental isotope effects in various enzymatic reactions, where they were ascribed to the tunneling.

Hydrochemical and isotopic characteristics of the Lodwar Alluvial Aquifer System (LAAS) in Northwestern Kenya and implications for sustainable groundwater use in dryland urban areas

Groundwater is a crucial resource for dryland regions such as this, where surface water resources are limited and unreliable. This paper presents a study of the Lodwar Alluvial Aquifer System (LAAS) in northwestern Kenya and its hydrochemical and isotopic characteristics, with the goal of understanding how to sustainably manage the groundwater system. As a result, the paper focuses on elucidating the hydrogeochemical and river-groundwater interaction (using environmental isotopes and major ion chemistry) of an aquifer that is located in the north-western dryland of Kenya. The study utilised environmental isotopes of oxygen-18 (18O), deuterium (2H), and tritium (3H) as tracers for establishing recharge sources and origin of groundwater. A sampling campaign involving 112 water samples was conducted to establish isotopic compositions of rain, spring, surface water (rivers, scoop holes, dams and lake) and groundwater at the peak of the wet season in May 2018. The tritium values in the study area ranged from 1.1 to 2.4 TU. Considering the median values of δ18O and δ2H in surface water and groundwater samples, four clusters emerge based on the degree of enrichment; Cluster 1 comprises the lake water (δ18O = +6.01, δ2H = +41.9); Cluster 2 is the Turkwel and Kawalase river water with slightly positive relative to VSMOW and with different δ2H values (+7.6‰ versus −9.8‰). The third cluster is the groundwater of the Shallow Alluvial Aquifer (SAA) and the Deep Aquifer (DA) (δ18O = −0.96‰ and −0.70‰; and δ2H = +0.4‰ and +0.6‰, respectively). The last cluster comprises the most isotope-depleted waters of water pans, scoop holes, Intermediate Aquifer (IA) and Turkana Grit Shall Aquifer (TGSA) with median values ranging from −2.87‰ to −2.48‰ for δ18O and −8.6‰ and −16.4‰ for δ2H. While the SAA is mainly recharge by the Turkwel River, a relationship is observed between the values deuterium in the Kawalase (−9.6‰ VSMOW) and IA (−8.6‰ VSMOW). Understanding recharge sources and aquifer vulnerability of similar strategic aquifers helps scientists appropriately advise policymakers and the water community who develop sustainable water use, aquifer protection and conservation strategies. In addition, the study contributes scientific evidence of isotopic compositions of groundwater in the Horn of Africa. Furthermore, the evidence of surface water-groundwater interaction presents a case of a fragile dryland ecosystem. Future work will involve the installation of piezometers in strategic aquifer zones to monitor groundwater levels in relation to river gauging data to quantify the amount of recharge and establish the impacts of rainfall variability in the upstream catchment.

Definition of Circulation Conditions and Groundwater Genesis of the Complex Krupaja Hydrogeological Karst System (Eastern Serbia)

The complex Krupaja karst system, located in Serbia, which consists of a strong karst spring, a thermal karst spring, and a borehole that captures sub-thermal waters, has been studied. A phenomenon which gives rise to the occurrence of karst waters of three different temperatures within a relatively short distance (about 200 m) led us to assume that these karst waters are formed within the same karst aquifer and circulate through different levels of karst channels that are zonally distributed within a vertical profile; this was confirmed by assessing the groundwater ages. Based on the development of karstification, as presented in this paper, as well as on previous investigations, explanations of four types of circulation within same karst system are provided. The results of measurements of stable isotopes (H, 18O, and 13C) and radioactive isotopes of tritium and T+He and 14C, as well as hydrochemical water analyses, speleogenetic spatial modeling, speleodiving research, etc., confirmed the assumption that these groundwaters belong to the same karst system. However, these karst waters have different residence times, i.e., from only a few days to over several decades and even up to approximately 4000 years, circulating through channels with various distributions along the depth of the karst aquifer.

The Use of Isotopic Techniques to Determine the Sources of Groundwater Recharge and Interaction with Surface Water in Southern Baghdad –Iraq

Isotope Hydrology has become a widely used technique for managing the global water crisis. The study of the Isotopic content of Groundwater and surface water and the study of chemical analysis is an important source of water sustainability. The study area is located south of Baghdad- Iraq three regions (Al-Dora, Al- Rustumiya and Al-Tuwaitha). Many samples were taken in the study area (15) samples Groundwater (well) and surface water (Rivers Tigris and Diyala). The results of the isotopic study indicated that there is a clear interaction in the values of the two stable isotopes between groundwater and surface water (Tigris and Diyala Rivers). In the wells (-41.5,-42.95 ‰) for deuterium (2H) (-6.77, -7.15 ‰) Oxygen-18 (18O) and the Tigris and Diyala rivers (-40 , - 39.47 - -7.34,-7.2 ‰) respectively ((2H), ((18O)) in the study area. Depending on these variables, indicates isotopic signatures similar between groundwater and surface water in the study area, helped in this the geological structures of the city of Baghdad (the sedimentation of the sedimentary plain). Through the results of isotope Tritium (H-3), (indicator to know the age of water and Recharge of water) we showed a clear convergence between the concentrations of tritium in the surface water of the rivers (Tigris and Diyala) (4.8 ± 0.064) TU and the wells (4.5 ±0.045) TU in the region, which indicates that the supply of water from wells is modern and continuous, and confirms the overlap between surface water and groundwater in the study area. It also indicated the high values of electrical conductivity in wells samples because most of the wells in the study area are shallow, where salt concentrations are high due to increased evaporation and are not suitable for drinking.

Density functional theoretical assessment of titanium metal for adsorption of hydrogen, deuterium and tritium isotopes

Density functional theoretical assessment of titanium metal for adsorption of hydrogen, deuterium and tritium isotopes

Assessment of Aquifer Recharge Potential Using Remote Sensing, GIS and the Analytical Hierarchy Process (AHP) Combined with Hydrochemical and Isotope Data (Tamassari Basin, Burkina Faso)

In the Tamassari basin, the agricultural population is highly dependent on groundwater resources for its socioeconomic development. However, the decrease in rainfall in the region since the late 1960s and the demographic pressure on the land are significantly affecting groundwater recharge. In order to exploit this groundwater sustainably, it is necessary to identify potential recharge areas for a better capitalisation of this resource. The objective of this study is to map the recharge potential of the existing aquifers making use of remote sensing and GIS techniques and to make a validation based on chloride and tritium contents in the borehole water. The processing carried out on the Landsat 5 and Landsat 8 images combined with a digital elevation model (ALOS PALSAR), highlight the lithological, linear and topographical characteristics of the study area. In addition, various supervised classification algorithms were used to produce the most accurate land use map. Field campaigns were conducted to validate the thematic maps resulting from the geospatial data processing and to collect water samples for hydrochemical (chloride) and isotopic analysis (tritium). The analytical hierarchy process (AHP) was used to derive recharge factors weights. The resulting recharge map shows a perfect agreement between the recharge classes derived from spatial modelling and the tritium isotope analyses. This was not the case with the chloride contents, which showed a dispersion over all the recharge areas.

Tritium separation from radioactive wastewater by hydrogen isotope-selective exchange of hydrogen-bonded fluorine

The separation of tritium (3H) from radioactive wastewater is a persistent challenging problem in the nuclear industry from an environmental perspective. This study provides new insight into the tritium separation by investigating hydrogen isotope-selective exchange reaction on hydrogen-bonded fluorine (F····H····O) site. In this study, fluorinated mesoporous silica, F-MCM-41_NCs were prepared as a novel tritium sorbent that showed a significantly enhanced tritium isotope separation factor (α) compared to the pristine MCM-41 (α = 1.2). The optimal α of 3.3 is achieved using 0.5F-MCM-41_NC prepared with 0.5 g of NH4F per gram of MCM-41. This optimal α is attributed to an excellent compromise between the amount and the stability of (NH4)2SiF6 on the pore channel with the integrity of the MCM-41 framework. Experimental, theoretical, and analytical characterization results consistently support chemical affinity quantum sieving effect at F····H····O hydrogen-bonding sites via the hydrogen isotope-selective exchange reaction as the dominant tritiumseparation mechanism.

Determination of Groundwater Recharge Mechanism Based on Environmental Isotopes in Chahannur Basin

In recent years, the lake area of the Chahannur Basin has been decreasing, leading to an increase in salt dust storms. In order to find out the recharge mechanism of groundwater in the Chahannur Basin, a total of 51 groundwater and surface water samples were collected. Tritium (3H) isotope and Freon (CFCs) were used to estimate the age of groundwater and preliminarily analyze the sources of groundwater recharge. The characteristics of hydrogen, oxygen, and strontium isotopes are used to indicate the characteristics of the water cycle in the Chahannur Basin. The results show that: (1) Two dating methods, tritium isotope (3H) and Freon (CFCs), are suitable for semi-quantitative dating of groundwater in the Chahannur Basin. (2) Hydrogen, oxygen, and strontium isotopes can be used to characterize the groundwater cycle in the Chahannur Basin. (3) The groundwater level around the Chahannur Lake area is low, and the groundwater in the Chahannur Basin flows from the southwest and northwest to the lake area. (4) The groundwater in the Chahannur Basin is mainly replenished by atmospheric precipitation, and the evaporation of groundwater and surface water is strong. The research results provide a basis for the study of measures to prevent the reduction in the Chahannur watershed area.

Entropy generation minimization-based heat transfer and mass transfer study of rectangular packed-bed filled with spherical particles

The study focuses on tritium-extraction and heat-extraction characteristics of the lead lithium ceramic breeder (LLCB) blanket module, an Indian tritium breeding blanket concept design in the International Thermonuclear Experimental Reactor (ITER). The present study focuses on the mass transfer phenomenon and entropy generation minimization (EGM)-based heat transfer analysis of the packed bed of a fusion reactor considering tritium isotopes in helium gas. For temperature-dependent convection-diffusion of tritium in helium gas and its permeation through the solid structure, a multi-region model in OpenFOAM using the locally varying porous medium approach is developed for studying the coupled multi-physics phenomena. For heat extraction behavior, a parametric study-based analysis is done using the EGM approach that involves irreversibility due to heat transfer, mass transfer, viscous, porosity effect, and heat generation rates. It is found that a lower Reynolds number (Re), and higher non-dimensional heat generation number (β), and non-dimensional species generation number (ϛ) result in a higher tritium extraction. In contrast, due to minimum total entropy generation, higher Re, and lower β and ϛ are preferred. Random packing arrangement as compared to BCC and FCC arrangements gives better tritium extraction and uniformity. However, the FCC arrangement is found as a better choice based on entropy minimization. Diagonally-opposite as compared to same-side inlet-outlet configuration extracts tritium more effectively and also found to be a better configuration from the EGM approach. The present work is significant since, for the breeder blanket, it presents the implementation of Sievert law boundary conditions and the EGM model for the first time in the literature.