Experimentation and modelling of U, Th, and lanthanides transport in fissured rocks. Influence of complexation
Description
A circulation between two drill holes in a granite after hydraulic fracturation (site INAG, le Mayet de Montagne, France) is experimented. UO2(CO3)34- and Th, La, Sm, Eu, Dy and Yb EDTA complexes are injected together. Different amounts of tracers are also inpected successively. Break through curves are similar for Th and Lanthanides, but somewhat different for U that shows increasing tailing. Recovery rates increase with increasing stability of the complex (41.4% for La to 96.7% for Yb in the third run) and with increasing amount of tracer. To account for indications of non linearity, a Freundlich isotherms: F=K.Csup(1/2), C= complexed tracer concentration in the fluid, F= tracers concentration adsorbed on the solid, K= global sorption constant, is used for EDTA tracer sorption. The experiments have demonstrated the importance of complexation and its consequence (non linearity) when experimenting and modelling elements transport
Availability note (English)
MF available from INIS under the Report Number.Abstract (French)
Trois experiences de tracages multiples ont ete realisees dans un reseau de fractures reliant deux forages dans un granite (Site INAG du Mayet de Montagne). Nous avons injecte simultanement 7 complexes: UO2(CO3)34- et des complexes EDTA de Th, La, SM, Dy et Yb. Pour chaque tracage, des masses differentes de chaque traceur ont ete injectees. Les courbes de restitution sont simulaires pour le Th et les Lanthanides, celles de l'U sont legerement decalees et ont un trainage plus accentue. Les taux de restitution varient de maniere croissante en fonction de la stabilite du complexe (41.4% pour La et 96.7% pour Yb dans le 3e tracage) et de la quantite injectee. Une modelisation numerique des tracages a permis de retrouver des resultats analogues en utilisant une loi d'absorption irreversible non lineaire de type Freundlich. Cette loi non lineaire est due a l'existence des complexes stabilisant le traceur en solution, et est de la forme F=(k,Kssup(1/2)).Csup(1/2),F = concentration absorbee, K = constante d'absorption, Ks = constante de stabilite du traceur, C = concentration du complexe en solution. Ces resultats demontrent l'importance des phenomenes de complexation et leurs consequences sur l'experimentation et la modelisation du transport d'elements en solutionFiles
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Additional details
Publishing Information
- Imprint Pagination
- 4 p.
- Report number
- CEA-CONF--7900
Conference
- Title
- 9. MRS Symposium.
- Dates
- 9-11 Sep 1985.
- Place
- Stockholm (Sweden).
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 16080383
- Subject category
- S58: GEOSCIENCES; S54: ENVIRONMENTAL SCIENCES; S12: MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ADSORPTION; CHEMISORPTION; DIFFUSION; FLOW MODELS; FRACTURES; GRANITES; GROUND WATER; RADIONUCLIDE MIGRATION; RARE EARTHS; THORIUM; URANIUM
- Descriptors DEC
- ACTINIDES; CHEMICAL REACTIONS; ELEMENTS; ENVIRONMENTAL TRANSPORT; FAILURES; HYDROGEN COMPOUNDS; IGNEOUS ROCKS; MASS TRANSFER; MATHEMATICAL MODELS; METALS; OXYGEN COMPOUNDS; PLUTONIC ROCKS; ROCKS; SEPARATION PROCESSES; WATER