LABORATORY SIMULATION OF GEOLOGICAL MIGRATION OF ACTINIDES UNDER VARIOUS OXIDATION STATES
The quantitative description of radionuclide migration in the geosphere demands that the environmental redox conditions which determine the oxidation state of multivalence elements are considered. Laboratory experiments which allow the identification of the mechanisms linked to the various oxidation states are then needed to evaluate the migration potential in the different geological formations under study. Due to the difficulty of reproducing in the laboratory the great variability of the natural conditions, typical model situations are being considered in this study; predominant interaction processes of radionuclides with the physical model considered are simulated separately in laboratory under the various physico-chemical conditions (pH, Eh, ligand concentration etc.) characterizing the natural variability. In this study which deals with the assessment of the long term risk linked to geological disposal of HLW, the radionuclides Np, Pu, Am and Tc are being considered; the physical model adopted corresponds to a porous media permeated with fresh and/or saline ground water. Problems connected with the transport of colloidal species, typical of low valence states, as well as of soluble species will be discussed in this paper following a theoretical and experimental approach.
Bibliographic Reference: WORKSHOP ON THE SOURCE TERM FOR RADIONUCLIDE MIGRATION FROM HIGH-LEVEL WASTE OR SPENT NUCLEAR FUEL UNDER REALISTIC REPOSITORY CONDITIONS, ALBUQUERQUE, N.M. (USA), NOV. 13-15, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31732 ORA
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Record Number: 1989123027100 / Last updated on: 1987-01-01
Available languages: en