The knowledge of aqueous speciation of uranium and radium in mining context is important for the modelling strategies based on reactive transport. The use of thermochemical databases allows accessing to theoretical speciation when the water compositions are known. If the usual concentration of radium in natural or anthropized waters is too low to have access to speciation experimentally, this can be achieved for uranium(VI), e.g. using time-resolved laser-induced fluorescence spectroscopy (TRLFS). In this work, theoretical radium and uranium inorganic and organic speciation were calculated using the water compositions collected in the legacymine site of Le Cellier (Loze`re, France) currently under monitoring after its closure and decommissioning, and database file extracted from the Prodata database for the PhreeqC and Orchestra codes. We also have measured TRLFS uranium spectra, which allows monitoring the uranium(VI) evolution from sulphate-like UO2(SO4)n2-2n complexes, at the beginning of the treatment, to characteristic CanUO2(CO3)3(4-2n)- complexes towards the end of the treatment, with an expected decrease of the total uranium concentration. Inorganic thermodynamic calculations are in excellent agreement with the spectroscopic attributions all along the treatment, whatever the speciation code used. The influence of natural organic matter, as part of the dissolved organic carbon outside of the legacy-mine perimeter, cannot be ruled out but is not straightforward to ascertain. The effluent seems only to disturb slightly the uranium speciation in the local stream from UO2CO3(aq) to CanUO2(CO3)3(4-2n)- due to calcium increase.

The formation constants of CanUO2(CO3)3(4-2n)- complexes were determined directly using capillary electrophoresis coupled with inductively coupled plasma mass spectrometry (CE-ICP-MS) in 0.1 M NaCl and at room temperature. Instead of conventional fused silica, polyetheretherketone (PEEK), a neutral organic material, was used as the capillary material to avoid interactions between uranyl and silica. Since PEEK is not optically transparent, a macrocyclic neutral complex, Ga-NOTA, was used to measure the electroosmotic flux directly by ICP-MS. The impact of the Joule effect was evaluated to control the temperature during electrophoresis. To alter the reversible interaction that arose from continuous use, a two-mode electrophoresis strategy was adopted. The observed mobilities of the samples showed a satisfactory correlation with the theoretical charge calculated from previous data (C. Shang and P. E. Reiller, Dalton Trans., 2020, 49, 466-481). The successive formation constants obtained in this work, log10 K(CaUO2(CO3)32-) = 5.28 +/- 0.39 and log10 K(Ca2UO2(CO3)3(aq)) = 8.46 +/- 0.67 in 0.1 M NaCl, were extrapolated to infinite dilution using the Davies equation, yielding log10 beta degrees(CaUO2(CO3)32-) = 27.12 +/- 0.39 and log10 beta degrees(Ca2UO2(CO3)3(aq)) = 30.30 +/- 0.67. These values are in excellent agreement with Shang and Reiller (C. Shang and P. E. Reiller, Dalton Trans., 2020, 49, 466-481). This further verifies the thermodynamic data available for these species and validates PEEK-based capillary electrophoresis for the measurement of thermodynamic constants of inorganic complexes in alkaline media.

The formation constants of CanAnO2(CO3)3(4-2n)- (An = U, Np, and Pu) are determined in 0.1 mol/kgwater NaClO4 medium at 25 °C via the coupling of capillary electrophoresis and inductively coupled plasma mass spectroscopy (CE-ICP-MS) using a poly(etheretherketone) (PEEK) capillaries. Prior to the calcium titration experiments, the stabilization of Np(VI) and Pu(VI) under the experimental conditions and their complexation behavior with carbonate were studied. The selection of literature data from limited available studies and the impact of minor AnO2(CO3)m2-2m species are also discussed. Experimental results indicate that for the three actinides, AnO2(CO3)m2-2m complexes form CaAnO2(CO3)32- complexes first and subsequently Ca2AnO2(CO3)3(aq) complexes, as already shown for U(VI). The cumulative stability constants at infinite dilution and at 25 °C are log10β°(CaUO2(CO3)32-) = 27.01 ± 0.11, log10β°(Ca2UO2(CO3)3(aq)) = 30.13 ± 0.16, log10β°(CaNpO2(CO3)32-) = 25.14 ± 0.28, log10β°(Ca2NpO2(CO3)3(aq)) = 28.64 ± 0.24, log10β°(CaPuO2(CO3)32-) = 25.85 ± 0.69, and log10β°(Ca2PuO2(CO3)3(aq)) = 29.15 ± 0.66. Theoretical calculations using the obtained data also suggest that the formation of CanAnO2(CO3)3(4-2n)- complexes favors the stabilization of Np(VI) and Pu(VI) in calcium- and carbonate-rich oxidant environments.

From the available thermodynamic data in the literature, a review of the impact of the formation of complexes between triscarbonatoactinyl(VI) and alkaline earth(II) (Ae) is estimated under varying conditions. First, after analyzing the literature data and using the ascertained thermodynamic data available from the commissioned reviews from the Nuclear Energy Agency (Organization for the Economic Cooperation and Development) Thermochemical DataBank Project on actinides (An) U, Np, and Pu, and from recently determined AenUO2(CO3)3(4−2n)- thermodynamic functions, the formation of AenAnO2(CO3)3(4−2n)– complexes for Pu(VI) and Np(VI) are estimated using linear free energy relationships (LFERs). The data are in good agreement with the sole determination of AePuO2(CO3)32− from Jo et al. (Dalton Trans. 49, 11605), which gives a relative confidence in the LFERs, and allows the application to actual situations. From existing uranium data, first, the impact of the origin of the data on the calculated predominance is addressed under 0.1 M NaCl and atmospheric CO2(g); second, the influence of ionic strength and salinity on predominance is estimated; and finally, the influence of temperature up to 50 °C on the solubility of uraninite in a deep geological radioactive waste storage or disposal site is calculated. For neptunium and plutonium, the impact of the potential log10β°(AenAnO2(CO3)3(4−2n)–) on Pourbaix diagrams of Pu and Np in Mg–Ca–CO3 media are estimated from Jo et al. (Dalton Trans. 49, 11605) and LFERs. Finally, the application to the speciation of Pu and Np in seawater is proposed.

Environmental context This study investigates how rare earth elements (REEs), such as europium (Eu), bind to organic matter. We are also gaining valuable insights into how these elements affect the structure of the organic matter that controls their mobility in natural systems, helping us to better understand the broader processes that govern the behaviour of trace metals in the environment.Rationale Humic substances (HS), including humic (HA) and fulvic (FA) acids, play a vital role in environmental systems, particularly in the sequestration and transport of trace metals. Although existing models like the NICA-Donnan model have illuminated metal-HS interactions, the effect of HS concentration on these interactions remains insufficiently explored.Methodology This study centres on Suwannee River fulvic acid (SRFA) and investigates how its concentration influences the dimensions and electrostatic characteristics of SRFA complexes, utilising europium(III) (EuIII) as a representative metal cation. The employed methodology involves Taylor dispersion analysis (TDA) with capillary electrophoresis to determine diffusion coefficients (D) and hydrodynamic radii (RH) of SRFA and EuIII-SRFA complexes. The NICA-Donnan model is employed to estimate site densities, intrinsic heterogeneity and Donnan potential (psi D).Results The RH values for SRFA and EuIII-SRFA complexes consistently fall between 0.78 and 1.03 nm, indicating that pH and SRFA concentration minimally affect complex size. Donnan volume calculations based on RH align well with the NICA-Donnan model. The results reveal changes in electrostatic properties, particularly the Boltzmann factor (chi), which is sensitive to SRFA concentration, exhibiting more pronounced effects in trivalent cation-containing SRFA complexes.Discussion The study underscores that the concentration of HS, such as SRFA, significantly influences the size and electrostatic attributes of SRFA complexes, potentially affecting the behaviour of other cations in environmental systems, including iron and aluminium. The findings highlight the importance of the metal to HS sites ratio in determining complex size and electrostatic properties, providing valuable insights into the behaviour of natural organic matter in diverse environmental contexts. The discussion emphasises the need for further research to explore the influence of different cations on HS structures across a broader concentration range.

We evaluated the potential of time-resolved laser-induced fluorescence spectroscopy (TRLFS) combined with chemometric methods for fast identification of U(VI)-bearing minerals in a mining context. We analyzed a sample set which was representative of several environmental conditions. The set consisted of 80 uranium-bearing samples related to mining operations, including natural minerals, minerals with uranium sorbed on the surface, and synthetic phases prepared and characterized specifically for this study. The TRLF spectra were processed using the Ward algorithm and the K-nearest neighbors (KNN) method to reveal similarities between samples and to rapidly identify the uranium-bearing phase and the associated mineralogical family. The predictive models were validated on an independent dataset, and then applied to test samples mostly taken from U mill tailings. Identification results were found to be in accordance with the available characterization data from X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). This work shows that TRLFS can be an effective decision-making tool for environmental investigations or geological prospection, considering the large diversity of uranium-bearing mineral phases and their low concentration in environmental samples.

A new method of HILIC coupled to ESIMS and ICPMS, combined with online specific isotopic dilution has been developed and downscaled to determine the affinity of hydrophilic molecules towards nat Sm and nat Nd.

Evaluation of the mobility behaviour of radionuclides under highly saline and alkaline conditions is a major concern for the performance assessment of radioactive waste disposal. The aim of this study was to determine the effect of up to 2.8 mol/kgsolution content of NaNO3, on the solubility and the retention of U(VI) at 22 °C onto a hardened cement paste (HCP) prepared from ordinary Portland cement (CEM I). To avoid the interference of the high salt concentration and ionic strength, and because of the expected low solubility of uranium under such alkaline conditions, time-resolved laser fluorescence spectroscopy (TRLFS) was selected to accurately measure U(VI) concentration in solution using the standard addition method in 85% H3PO4. This allows both limiting the dilution and matrix effects and determining the resulting [U(VI)] in solution with acceptable precision for the distribution factor (Rd) in both sorption and desorption experiments. The operational solubility limit measured at high ionic strength lowered by a factor of three compared to the reference cementitious condition, and its Rd values decreased by a factor ca. four. The sorption of U(VI) appears to be reversible under these conditions.

In the framework of the French deep geological repository for radioactive waste, cement-based materials are envisaged to immobilize radionuclides and/or provide protection from radiation to the environment. Superplasticisers (SPs) are added to these materials to increase their workability. SPs will undergo degradation by coupled radiolytic and hydrolytic effects in the pore solution leading to the formation of potentially complexing degradation products. The objective was to study the potential effect of radiolyzed superplasticizers contained in cement-based materials on radionuclide uptake. The Eu speciation and solubility with organic ligands resulting from the degradation of SPs were studied for the two solutions and the results were compared. Two different SPs were selected, a polycarboxylate ether and a polynapthalene sulfonate. Two different protocols were followed: direct irradiation of the solution containing the superplasticizer, and irradiation of the compacted cement sample followed by extraction of the pore water. Solubility enhancements observed in artificial cement waters are not representative of real cement pore water interactions, in agreement with other studies. Finally, the effects of alkaline hydrolysis and radiolysis of SPs on Eu solubility in pore water are limited.

The formation of alkaline earth(II)triscarbonatouranyl(VI) (AenUO2(CO3)3(4-2n)-) species that have been evidenced both in laboratory and in-field studies, is important from slightly acidic pH up to near degraded cementitious in carbonated waters. They are also showing distinctive luminescence properties with a hypsochromic shift relative to UO22+. The conditions of pH, activities of alkaline earth(II) free ions (mostly Mg2+ and Ca2+) and carbonate ions (HCO3-) can be predicted from the thermodynamic functions and constants. The predictive validity of the activity of major alkaline ions (mostly Na+) is determined from the models used to describe the ionic strength comportment of these species, particularly using coefficients from the specific ion interaction theory (SIT). The stability domains of these species are better defined as a function of the activity of the constituents, and applied to natural waters. In this work, using recently obtained complete thermodynamic data and SIT coefficients, we will draw the stability domains of the AenUO2(CO3)3(4-2n)- species in combinations of activities of H+, HCO3-, Mg2+, Ca2+, and Na+ for a wide selection of water compositions from the literature. Water samples were collected near a French mining legacy-site (Site du Bosc, Lodève, France). After determining the major ion compositions, we will verify that the luminescence signal of uranium is in agreement with the predicted speciation in the stability domains.

The complex formation of triscarbonatouranyl(VI) UO2(CO3)34- with the alkaline earth metal ions Mg2+ and Ca2+ in 0.10 mol kgw-1 NaCl was studied at variable temperatures: 5-30 °C for Mg2+ and 10-50 °C for Ca2+. Under appropriate conditions, the ternary complexes (MnUO2(CO3)3(4-2n)- with n = 1 for Mg, n = {1; 2} for Ca) were identified by time-resolved laser-induced luminescence spectrometry. Their pure spectral components at 50 °C for CanUO2(CO3)3(4-2n)- and 30 °C for MgUO2(CO3)32- were recovered by multivariate curve resolution alternating least-squares analysis. Approximation models were tested to fit the experimental data-the equilibrium constants of complexation measured at different temperatures-and deduce the thermodynamic functions, i.e., enthalpy, entropy, and heat capacity. The weak influence of temperature on complexation constants induces large uncertainties in terms of thermodynamic functions. Assuming the enthalpy is constant with temperature using the Van't Hoff equation, the first stepwise complexation of UO2(CO3)34- by Ca2+ is estimated to be slightly endothermic, with , while the second stepwise complexation of CaUO2(CO3)32- by Ca2+ with is slightly exothermic, . In contrast to Ca2+, the complexation of UO2(CO3)34- by Mg2+ is slightly exothermic, with . These values are not significantly different from zero inasmuch as the uncertainties are important due to a weak dependence of log10 K° values. The entropic character of the complexation is verified as for the first stepwise complexation of UO2(CO3)34- by Ca2+, for the second stepwise complexation of CaUO2(CO3)32- by Ca2+, and for the complexation of UO2(CO3)34- by Mg2+. The energetics of complexation and sensitivity analysis of the model estimates with temperature are discussed. The uranium speciation in the case of the safety of nuclear waste management, using the present thermodynamic functions, provides support to the assessment of underground nuclear waste repositories.

The formation constants and specific ion interaction coefficients of MgUO2(CO3)32- complex were determined in 0.1 to 1.0 mol kgw-1 NaCl and 0.10 to 2.21 mol kgw-1 NaClO4 media in the framework of the specific ion interaction theory (SIT), by time-resolved laser-induced luminescence spectroscopy. The upper limits of ionic strength were chosen in order to limit luminescence quenching effects generated by high concentrations of Cl- and ClO4- already observed during our earlier studies on CanUO2(CO3)3(4-2n)- complexes (Shang & Reiller, Dalton Trans., 49, 466; Shang et al., Dalton Trans., 49, 15443). The cumulative formation constant determined is , and the specific ion interaction coefficients are ε(MgUO2(CO3)32-, Na+) = 0.19 ± 0.11 kgw mol-1 in NaClO4 and ε(MgUO2(CO3)32-, Na+) = 0.09 ± 0.16 kgw mol-1 in NaCl. Two gratings of 300 and 1800 lines per mm were used to acquire MgUO2(CO3)32- luminescence spectra, where the high-resolution 1800 lines per mm grating detected slight spectral shifts for the principal luminescent bands relative to CanUO2(CO3)3(4-2n)-. The applications of the consistent set of thermodynamic constants and ε values for MnUO2(CO3)3(4-2n)- (M = Mg and Ca) were examined in different geochemical contexts, where Mg over Ca concentration ratio varies to help defining the relative importance of these species.

The speciation of uranium is of great importance for a reliable prediction of its transport from disposal and storage site of radioactive waste into various geochemical environments. In particular, the ubiquitous presence of magnesium/calcium and carbonate in natural water systems renders the formation and chemical behaviour of uranium in Mg/Ca-CO 3 rich waters important to be elucidated. Since their first evidence in the 1990’s, the Mg/Ca n UO 2 (CO 3 ) 3(4-2n)- complexes have been the subject of several studies. Nevertheless, the evolution of the formation constants of at varying ionic strength has only been merely the subject of attention, which leaves the subject of the thermodynamic constants in the standard state a matter of debate. In this study, the formation constants of Mg/CaUO 2 (CO 3 ) 32 ‑ and Ca 2 UO 2 (CO 3 ) 3 (aq) were determined in varying ionic strength in NaCl and NaClO 4 media, using time-resolved laser-induced luminescence spectroscopy (TRLS). Spectroluminescence titration of UO 2 (CO 3 ) 34-complex by Mg 2+ /Ca 2+ were conducted at atmospheric CO 2 (g) and varying pH values in order to avoid the precipitation of both schoepite (UO 3 :2H 2 O) and Mg/Ca carbonate minerals in aqueous solutions. The stoichiometry of Mg 2+ /Ca 2+ was evidenced by the slope analyses corrected by the Ringböm coefficient of UO 2 (CO 3 ) 34– relative to pH and CO 2 (g), instead of the typical expression relative to UO 22+ and CO 32– . In the range of studied ionic strength, satisfactory linear fits assessed the stepwise formation constants, the values of which were

In case of nuclear accident, Sr-90 and Cs-134,Cs-137 are major radionuclides to account. In previous works (Appl. Geochem. 87, 167; ibid 93, 167), a database of ion-exchange parameters allowing the description of the Sr2+ and Cs+ adsorption on purified illite and smectite was developed for a multi-site ion-exchange (MSIE) model. In this study, the adsorption behaviours of Sr2+ and Cs+ were obtained with <150 mu m fractions of French soil samples: a cambisol fluvic, a calcosol, and a cambisol typic. The <2 mu m fractions of the soil samples were analysed by X-ray diffraction to estimate their clay minerals proportions that were then approximated to an illite/smectite mixture, in consistency with the CEC of the <150 mu m fractions. The database was implemented with K-illite and -smectite parameters to account for the amendment of K+ in agricultural soils. The isotherms of Sr2+ and Cs+ on the three soils - at 0.033 mol kg(w)(-1) CaCl2 (I = 0.1 mol kg(w)(-1)) and at the pH value of the water equilibrated with the soils - were then compared with simulations obtained using ion-exchange parameters from the database for the MSIE model. This simulation approach, based on the additive adsorption properties between several reactive phases, allowed to describe satisfactorily the adsorption of Sr2+ and Cs+ in most cases. In order to highlight the limiting parameters of the modelling predictive ability, different treatments were made on soil samples. The removal of the natural organic matter did not change significantly the adsorption behaviour of either Sr2+ or Cs+. The removal of the exchangeable aluminium from the cambisol typic allowed a better simulation of the adsorption isotherm in the case of Sr2+. Finally, in the case of the calcosol, the satisfactory modelling of the decrease in adsorption of Sr and Cs using a synthetic CaCl2 pore water with increasing concentrations of KNO3 allowed to verify the robustness of the MSIE model and exchange parameters from the database.

Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties in osteosarcoma (bone tumor). These EPSs could be employed as new drug delivery systems for therapeutic uses. They may represent a new class of ligands to be combined in a theranostic approach with fluorescent metals, such as Eu(III), to serve as imaging probe. The goal of this work was to investigate the feasibility of such coupling by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Since these EPSs are polyelectrolytes their conformation could affect the complexation properties. Thus, viscosimetric measurements were performed as a function of their concentration as well as the background electrolyte concentration. Polysaccharides conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration but no change was evidenced when increasing europium concentration. Two sites of complexation of Eu(III) were evidenced by TRLFS in heparin, whereas only one site was evidenced in two modified EPSs produced from Alteromonas infernus.

(1) Background: Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties. They may represent a new class of ligands to be combined with theranostic radionuclides, such as 47Sc/44Sc. The goal of this work was to investigate the feasibility of such coupling. (2) Methods: EPSs, as well as heparin used as a drug reference, were characterized in terms of molar mass and dispersity using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering (AF4-MALS). The intrinsic viscosity of EPSs at different ionic strengths were measured in order to establish the conformation. To determine the stability constants of Sc with EPS and heparin, a Free-ion selective radiotracer extraction (FISRE) method has been used. (3) Results: AF4-MALS showed that radical depolymerization produces monodisperse EPSs, suitable for therapeutic use. EPS conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration. The LogK of Sc-EPS complexes have been determined and showing that they are comparable to the Sc-Hep. (4) Conclusions: EPSs are very promising to be coupled with the theranostic pair of scandium for Nuclear Medicine.

Abstract To investigate the extraction of uranium(VI) in HCl media by Aliquat® 336 in 1:99 (v:v) 1-decanol:n-dodecane mixture, our objective is to identify the complexe(s) in the organic phase by time-resolved laser-induced luminescence spectroscopy (TRLS). The extraction mechanism is supposed to involve the formation of [ U O 2 C l 4 2 − ⋅ ( R 4 N + ) 2 ] $[U{O_2}Cl_4^{2 - } \cdot {({R_4}{N^ + })_2}]$ in the organic phase. The occurrence of such a species leads to the presence of the UO 2 Cl 4 2 − ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ species in the organic solution, which luminescence shows particular features. The luminescence spectra and decay time evolutions are obtained in the organic phase as a function of HCl concentration in the aqueous phase (0.5–6 M). The extraction of UO 2 Cl 4 2 − ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ is confirmed by the particular spectrum of uranium(VI) in the organic phase, and the typical splitting of the luminescence bands, due to the crystal field effect, is clearly evidenced. The stoichiometry is verified using luminescence intensity variation as a function of the activity of Cl−, and extraction constants are calculated both using the specific interaction theory and Pitzer model. A decomposition of the spectrum of the extracted complex in the organic phase is also proposed. The decay time variation as a function of temperature allows estimating the activation energy of the luminescence process of the extracted complex.

The stability constants of ternary calcium uranyl tricarbonate complexes, CaUO2(CO3)(3)(2-) and Ca2UO2(CO3)(3)(aq), were determined in NaClO4 medium at various ionic strengths using time-resolved laser-induced luminescence spectroscopy (TRLS) - also known as time-resolved laser-induced fluorescence spectroscopy (TRLFS). As in a previous study, the potential precipitation of schoepite (UO3 center dot 2H(2)O) and calcite (CaCO3) was avoided via titration of the triscarbonatouranyl complex with Ca2+ at varying pH values. The Ringbom coefficients relative to UO2(CO3)(3)(4-) were individually evaluated under test sample conditions. Steadily enhanced luminescence intensity and increased decay-times were representative of complexation processes. The stoichiometry of calcium was quantified by slope analysis, and its measured intensity was corrected by using the corresponding Ringbom coefficient. The conditional formation constants, i.e. log(10) K-n.1.3, were then assessed after rounding off the slope values to their nearest integers. Cumulative formation constants at infinite dilution log(10) beta degrees(n.1.3), and specific ion interaction parameters epsilon were determined based on the experimental origin and slope values, respectively, over the range of 0.1-2.46 mol kg(w)(-1) NaClO4 using the specific ion interaction theory (SIT) approach. The cumulative stability constants are log(10) beta degrees(CaUO2(CO3)(3)(2-)) = 27.26 +/- 0.04 and log(10) beta degrees(Ca2UO2(CO3)(3)(aq)) = 30.53 +/- 0.06. The specific ion interaction coefficients are estimated to be epsilon(CaUO2(CO3)(3)(2-),Na+) = (0.02 +/- 0.04) kg(w) mol(-1) and epsilon(Ca2UO2(CO3)(3)(aq),NaClO4) = (0.18 +/- 0.07) kg(w) mol(-1). These latter values are different from the ones that were previously obtained in NaCl, and underlying causes are discussed from different aspects. This work provides valuable information to address the interaction effects between Ca-UO2-CO3 species and 1 : 1 type electrolytes. It is suggested that the affinity of the cation in a background electrolyte with CanUO2(CO3)(3)((4-2n)-) (n = {1;2}) has to be taken into consideration at high ionic strengths, especially for globally non-charged species.

A growing demand exists on the monitoring of both uranium mining activities and their environmental impacts. In order to help understanding and modelling both these aspects, a thermodynamic database dedicated to uranium mining activities is developed: the PRODATA database. Relevant species and phases for uranium and radium are chosen from existing compilations of data, complemented with important missing data for the application to mining activities and environmental monitoring. Important major anions and cations chemistry are included, as well as secondary pollutants such as arsenic, lead, or nickel. Applications of the PRODATA extracted database file for PhreeqC to theoretical speciation calculations of uranium and radium for actual water compositions - either linked to uranium mining activities, or under monitoring for environmental survey - are presented. Wider applications to other available water compositions from different geochemical concepts are also tested. For the tested cases, the major radium and uranium species obtained using PRODATA are compared with other available thermodynamic database (Thermochimie, LLNL, Wateq4f, Minteq, PSI/NAGRA). The choice of the database file - and of the ionic strength correction - can strongly impact the final speciation results. Sulphate complexes of radium and uranium are of particular importance in mining exploitation context, and carbonate uranium complexes - particularly [Formula: see text] complexes - are crucial for environmental monitoring. The latter complexes are key species for the aqueous speciation of uranium, even in reducing environment where U(IV) low solubility usually governs uranium mobility.