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Reactive transport modelling of the long-term interaction between carbon steel and MX-80 bentonite at 25 °C

Chaparro, M. C.; Finck, N. ORCID iD icon; Metz, V. ORCID iD icon; Geckeis, H.


The geological disposal in deep bedrock repositories is the preferred option for the management of high-level radioactive waste (HLW). In some of these concepts, carbon steel is considered as a potential canister material and bentonites are planned as backfill material to protect metallic waste containers. Therefore, a 1D radial reactive transport model has been developed in order to better understand the processes occurring during the long-term iron-bentonite interaction. The numerical model accounts for diffusion, aqueous complexation reactions, mineral dissolution/precipitation and cation exchange at a constant temperature of 25 °C under anoxic conditions. Our results suggest that Fe is sorbed at the montmorillonite surface via cation exchange in the short-term, and it is consumed by formation of the secondary phases in the long-term. The numerical model predicts precipitation of nontronite, magnetite and greenalite as corrosion products. Calcite precipitates due to cation exchange in the short-term and due to montmorillonite dissolution in the long-term. Results further reveal a significant increase in pH in the long-term, while dissolution/precipitation reactions result in limited variations of the porosity. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000140687
Veröffentlicht am 06.12.2021
DOI: 10.3390/min11111272
Zitationen: 9
Web of Science
Zitationen: 8
Zitationen: 8
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2075-163X
KITopen-ID: 1000140687
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Erschienen in Minerals
Verlag MDPI
Band 11
Heft 11
Seiten Art.Nr.: 1272
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Vorab online veröffentlicht am 16.11.2021
Schlagwörter radioactive waste disposal; iron–bentonite interaction; reactive transport; numerical model
Nachgewiesen in Web of Science
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