Objective
The aim of the research programme is to examine, quantify, and model the role of humic substances in radionuclide migration. The programme will focus on proposed repositories within the European Community member states and site-specific materials will be used. Experimental results with natural substances will be directly applied to geochemical complexation and transport models. To achieve these goals, the programme is divided into six tasks: 1. Collection and characterisation of site specific samples
2. Complexation of actinides and major cations with humic and fulvic acids 3. Effect of humic substances on transport
4. Model development
5. Model testing
6. Role of humic
substances for performance assessment In the first three tasks, environmental samples will be collected, characterised, and used in experiments. The final three tasks involve model development, validation and application. The tasks will run concurrently and the relationship between modellers and experimentalists will be interactive to ensure that the necessary data is acquired and appropriate models are developed and applied. In Task 1, humic substances, groundwaters, sediments and rocks will be collected and analysed. Purified humic substances and geological materials will be distributed to participating laboratories. Task 2 examines the complexation reactions of actinides and major cations with humic and fulvic acids. Emphasis will be placed on examining conditions similar to natural systems. Special prominence will be given to the non-trivalent actinide elements, since results on the complexation of these elements with humic substances are generally lacking in the literature. Task 3 examines the interaction amongst metal ions, humic substances, and geological materials. The solid phases to be examined are the host geological materials and individual components of these materials. The objective of Task 4 is to develop predictive models for metal ion complexation with humic substances and humic substance-mediated metal-ion transport through geological materials. The models developed in Task 4 will be used to blind predict the results from well-defined laboratory experiments. In the final task, Task 6, the developed model will be used to assess under which conditions are humic substances involved in radionuclide complexation and transport. The model will be applied to a number of different geological systems, such as salt domes, granitic, or clay, which are proposed as potential long term radioactive waste disposal site by European Community member states. This will provide a scientifically based analysis on the importance and role of humic substances in the safety assessment of disposal sites.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
76344 EGGENSTEIN-LEOPOLDSHAFEN
Germany