GEOC 44 |
| Wolfgang Hummel, Waste Management Laboratory, Waste Management Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland |
| World wide, a substantial effort is put into geochemical research programmes aiming at a deeper understanding of the processes governing the long-term behavior of toxic metals (radionuclides) in planned nuclear waste repositories. The first models describing the migration of radionuclides contained only one "geochemistry coefficient", Kd, the distribution of radionuclides between solid and aqueous phase. Later, a second "geochemistry parameter" was added to the models, the solubility of pure solid phases. Nowadays, a large body of knowledge has been accumulated concerning sorption processes, coprecipitation and formation of solid-solutions of radionuclides with host phases. However, the models actually used for safety assessment calculations still dwell on the same two "geochemistry parameters", Kd and solubility. A few worked examples from a recent Swiss safety assessment study show how the state-of-the-art geochemical process understanding was used to derive site-specific databases of Kds and solubility limitations |
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Chemistry of Metals in Terrestrial and Aquatic Systems
1:30 PM-5:10 PM, Monday, March 29, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |