Objectif The experimental research carried out in INTAS project 97-0073 established that tritium enters different structural positions of clay minerals such as montmorillonite, kaolinite and palygorskite, demonstrating the dependence of tritium accumulation in the minerals on their structural type, time of the interaction with heavy water and specific activity of tritium. The data also indicate that the mechanism of protium-tritium exchange in different types of minerals and in their different structural positions is different. To understand the physical constraints needed for a repository for Tritium-bearing radioactive waste, and for the protection of environment from tritium pollution, it is necessary to understand the mechanism by which Tritium is retained in the structure of phyllosilicates, and to develop a new approach to identifying potentially suitable mineral matrices.In this connection, the main aims of the project are:- To define mechanisms of Tritium uptake, accumulation and storage in the different structural sites of phyllosilicates (isotopic exchange mechanisms);- To define the most effective mineral types, their mixtures and multi-layer composites to accumulate and to retain Tritium, for environmental protection in sites of Tritium-bearing radioactive waste storage;- To determine the specifications of the mineral mixture and multi-layer composites for the greatest Tritium accumulation and retention;- To evaluate the potential effectiveness of Tritium accumulation and retention in the proposed new mineral mixtures and multi-layer composites.These aims will be achieved through the following tasks:Task 1. To simulate the mechanisms of tritium accumulation and retention in phyllosilicates, involving theoretical and laboratory studies of diffusion of heavy hydrogen isotopes from liquid phases into the different structural positions of various minerals under natural conditions and under gamma-irradiation of the " mineral - heavy water " systems, taking into account the physico-chemical properties of the water phase and the structural features of the mineral phase, and an estimation of the role of? 2? and OH - groups molecules in Titium capture by the mineral structure;Task 2. To reveal prospective phyllosilicates, new mineral mixtures and composites for environmental protection, involving modelling the mechanism of Tritium uptake, accumulation and retention by phyllosilicates, the selection of prospective mineral matrices, understanding how to make new mineral mixtures and multilayer composites, and determining the criteria of their efficiency, taking into account the hydrodynamic conditions of the geological environment of tritium waste storage (on an example of test objects).The project will have the following verifiable deliverables:- Integrated methodological approach to evaluate tritium retention in phyllosilicates;- Kinetic parameters of the redistribution of heavy hydrogen isotopes between aqueous phase and mineral matrix;- Comprehension of the physico-chemical essence of the mechanisms of protons - heavy hydrogen isotopes exchange in OH-groups of the mineral structure;- The theoretical basis for creation of the mineral mixtures and other composites, which can be utilised for environmental protection from tritium pollution;- The evaluation of using available low-priced adsorbents on the basis of phyllosilicates as engineering barriers underneath Tritium waste repositories, located in geological formations.The detailed study of the mechanisms of tritium entering, accumulating and bounding (retention) in phyllosilicates will result in new knowledge about hydrogen isotopic exchange in the system "water-mineral", and in the creation of new effective mineral barriers for environmental protection from tritium contamination. Programme(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Thème(s) 5 - Earth Sciences, Environment, Energy OPEN - OPEN Call Appel à propositions Data not available Régime de financement Data not available Coordinateur University of Granada Contribution de l’UE Aucune donnée Adresse Avenida Fuentenueva s/n 18002 Granada Espagne Voir sur la carte Coût total Aucune donnée Participants (4) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire National Academy of Sciences of Belarus Biélorussie Contribution de l’UE Aucune donnée Adresse Kuprevich Street 7 220141 Minsk Voir sur la carte Coût total Aucune donnée SELOR EEIG Pays-Bas Contribution de l’UE Aucune donnée Adresse SAFFIERSTRAAT 101 C AMSTERDAM Voir sur la carte Coût total Aucune donnée State scientific centre of environmental radiogeochemistry Ukraine Contribution de l’UE Aucune donnée Adresse 34a Palladin ave. 03 Kiev Voir sur la carte Coût total Aucune donnée Ukrainian Scientific Research Institute of Ecological Problems Ukraine Contribution de l’UE Aucune donnée Adresse 6 Bakulina Str 61166 Kharkov Voir sur la carte Coût total Aucune donnée
