Euradwaste '08 - EU Bookshop - Europa

Summary
FUNMIG – Research on Well-defined Processes
Pascal Reiller
CEA-Saclay, France
The First Research, Technological Development Component (RTDC) from the Integrated Project
FUNMIG was devoted on the assessment of basic thermodynamic data and constants, as
well as basic principles necessary to describe the speciation of radionuclides, their sorption on
minerals, influence of organics and solid-solution formation in the far field of a radioactive
waste disposal site. It includes a large number of European teams that shared and confronted
their particular expertises and views. Common points were identified throughout this project,
which gave the opportunity of common works.
1. Introduction
Main objectives of the integrated project FUNdamental processes of radionuclides MIGration
(FUNMIG) are the fundamental understanding of radionuclide migration processes in the geosphere,
especially focused on tools for application to performance assessment (PA). It is structured
in seven components, two on acquisition of data and validation of models at the laboratory level,
three components are dedicated to host rock specific studies, one is dedicated to the abstraction of
the generated to PA, and last component is devoted to knowledge transfer and training.
The first research, technological development component (RTDC-1) from FUNMIG, regrouping
17 partners from 10 countries, is dedicated to provide fundamental process knowledge and the required
data for processes with comparably well established conceptual understanding. Processes
studied are fundamental and applicable to all types of host rocks and the proper parameters are derived
for the relevant migration systems. The outcome is the fundamental understanding and quantification
of the processes studied. The models are developed at the research model level. It is organised
in four work packages to provide data on (i) ionic species/speciation of radionuclides, processes
determining physico-chemical conditions and generation of missing thermodynamic data, (ii)
ion exchange and surface complexation modelling to described the retention phenomena of radionuclides
by mineral, (iii) the influence of organics, either natural or anthropogenic, on the retention
of radionuclides by minerals, and (iv) formation of solid solutions and secondary phases including
retardation of anions.
RTDC-1 is aiming at proposing solution for the following key scientific questions. Are needed
thermodynamic data available and accurate? Can sorption models calculate sorption isotherms
measured under chemically realistic conditions? Are the modelling simplification justified regarding
spectroscopy? What is the influence of radionuclide complexation on sorption and can this influence
be quantitatively calculated with the sorption models? Is the influence of natural organic
matter on sorption described by thermodynamics? Can we mend the bridge between sorption and
solid solution?
497