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Barcelona, Spain

Raposo J.R.,University of Santiago de Compostela | Dafonte J.,University of Santiago de Compostela | Molinero J.,Amphos 21
Hydrogeology Journal | Year: 2013

Climate change can impact the hydrological processes of a watershed and may result in problems with future water supply for large sections of the population. Results from the FP5 PRUDENCE project suggest significant changes in temperature and precipitation over Europe. In this study, the Soil and Water Assessment Tool (SWAT) model was used to assess the potential impacts of climate change on groundwater recharge in the hydrological district of Galicia-Costa, Spain. Climate projections from two general circulation models and eight different regional climate models were used for the assessment and two climate-change scenarios were evaluated. Calibration and validation of the model were performed using a daily time-step in four representative catchments in the district. The effects on modeled mean annual groundwater recharge are small, partly due to the greater stomatal efficiency of plants in response to increased CO2 concentration. However, climate change strongly influences the temporal variability of modeled groundwater recharge. Recharge may concentrate in the winter season and dramatically decrease in the summer-autumn season. As a result, the dry-season duration may be increased on average by almost 30 % for the A2 emission scenario, exacerbating the current problems in water supply. © 2012 Springer-Verlag Berlin Heidelberg. Source

Richard L.,University of Lorraine | Gaona X.,Amphos 21 | Gaona X.,Karlsruhe Institute of Technology
Geochimica et Cosmochimica Acta | Year: 2011

A critical evaluation has been made of the thermodynamic properties reported in the literature for 43 organic iodine compounds in the solid, liquid, or ideal gas state. These compounds include aliphatic, cyclic and aromatic iodides, iodophenols, iodocarboxylic acids, and acetyl and benzoyl iodides. The evaluation has been made on the basis of carbon number systematics and group additivity relations, which also allowed to provide estimates of the thermodynamic properties of those compounds for which no experimental data were available. Standard molal thermodynamic properties at 25 °C and 1 bar and heat capacity coefficients are reported for 13 crystalline, 29 liquid, and 39 ideal gas organic iodine compounds, which can be used to calculate the corresponding properties as a function of temperature and pressure. Values derived for the standard molal Gibbs energy of formation at 25 °C and 1. bar of these crystalline, liquid, and ideal gas organic iodine compounds have subsequently been combined with either solubility measurements or gas/water partition coefficients to obtain values for the standard partial molal Gibbs energies of formation at 25 °C and 1 bar of 32 aqueous organic iodine compounds. The thermodynamic properties of organic iodine compounds calculated in the present study can be used together with those for aqueous inorganic iodine species to predict the organic/inorganic speciation of iodine in marine sediments and petroleum systems, or in the near- and far-field of nuclear waste repositories. © 2011 Elsevier Ltd. Source

Reiller P.E.,CEA Saclay Nuclear Research Center | Vercouter T.,CEA Saclay Nuclear Research Center | Duro L.,Amphos 21 | Ekberg C.,Chalmers University of Technology
Applied Geochemistry | Year: 2012

In this paper some of the needs for good quality thermodynamic data in radioactive waste management are highlighted. A presentation of the thermodynamic data produced within the 6th EC framework programme integrated project FUNMIG (Fundamental processes of radionuclide migration) and how these have helped in filling relevant thermodynamic data gaps is given. The manuscript does not intend to be a complete review of thermodynamic data, but a short overview of the aqueous complexation of Am(III), lanthanides (III), U(VI), and Th(IV) by sulfates, silicates, carbonates and phosphates. The work presented is based on the latest developments published in the literature and specifically addressed within the IP FUNMIG. © 2011 Elsevier Ltd. Source

Pique A.,CAT ENVIRO Geochemical Consultancy | Arcos D.,Amphos 21 | Grandia F.,Amphos 21 | Molinero J.,Amphos 21 | And 2 more authors.
Ambio | Year: 2013

Scenarios of barrier failure and radionuclide release to the near-surface environment are important to consider within performance and safety assessments of repositories for nuclear waste. A geological repository for spent nuclear fuel is planned at Forsmark, Sweden. Conceptual and numerical reactive transport models were developed in order to assess the retention capacity of the Quaternary till and clay deposits for selected radionuclides, in the event of an activity release from the repository. The elements considered were carbon (C), chlorine (Cl), cesium (Cs), iodine (I), molybdenum (Mo), niobium (Nb), nickel (Ni), radium (Ra), selenium (Se), strontium (Sr), technetium (Tc), thorium (Th), and uranium (U). According to the numerical predictions, the repository-derived nuclides that would be most significantly retained are Th, Ni, and Cs, mainly through sorption onto clays, followed by U, C, Sr, and Ra, trapped by sorption and/or incorporation into mineral phases. © 2013 The Author(s). Source

Grive M.,Amphos 21 | Duro L.,Amphos 21 | Colas E.,Amphos 21 | Giffaut E.,Andra Inc
Applied Geochemistry | Year: 2015

The thermodynamic database ThermoChimie is developed to meet the needs of performance assessment of radioactive waste disposals, particularly in the context of the Cigéo project (www.cigéo.com). To this purpose, the selection of thermodynamic data on radionuclides and chemotoxic elements has been subject to special attention. The aim of this publication is to present the methodology used in the selection of data on radiological and chemical pollutants in the disposal context for ThermoChimie. Data on radionuclides have been selected in the range of conditions of interest for the French radioactive waste disposal concepts, under Callovo-Oxfordian and cementitious conditions. Temperatures up to the thermal peak of 90. °C and high ionic strengths likely developed due to the degradation of certain ILW-LL waste packages are considered in the selection of thermodynamic data in ThermoChimie. The validity of the selected data is assessed with regard to experimental laboratory results as well as natural analogue systems. The selection of stability constants of aqueous species and solid compounds of radionuclides is based on literature review, dedicated experimental programs and estimation methods, leading to consistent data sets with associated uncertainties. The ThermoChimie database is presented as an efficient support to performance assessment, with traceable references and uncertainties for each datum. All the data are accessible under the public website www.thermochimie-tdb.com. © 2014 Elsevier Ltd. Source

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