CIEMAT Publications
ISSN: 2695-8864 | NIPO: 832-22-007-5
PUBLISHED IN 2022
Informes técnicos CIEMAT
Analysis of the colloidal properties of different clay minerals: impact on barrier performance
Missana, T.; Alonso de los Ríos, U.; Fernández Díaz, A. M.
Free
Abstract
This study analysed the characteristics of colloids generated from different smectites, used as engineered barriers in high-level radioactive waste (HLRW) repositories. The erosion of the bentonite would pose a potential problem, because a significant mass loss may jeopardize the performance of the material; furthermore, clay colloids formation from the eroded material may play a role on radionuclide transport.
The main characteristics of the colloids generated by different smectites (as the main mineral in bentonites), -mass of colloidal particles, particle size and surface electrical charge-, are related to the intrinsic physicochemical properties of the clay: exchangeable cations, total electrical charge and its distribution between the tetrahedral and octahedral layer.
As final aim, the formation of colloids was compared to the erosion experienced by the same bentonites in compacted and confined conditions, simulating the conditions present in HLRW repository and the results obtained with the dispersed material were verified in a very satisfactory way.