Competitive effect of the metallic canister and clay barrier on the sorption of Eu3+ under subcritical conditions

An in depth knowledge and understanding of high activity radionuclide (HLRW) immobilization processes on the materials composing the engineered barrier (clay and metallic canister) is required to ensure the safety and the long-term performance of radioactive waste disposal procedures. Therefore, the...

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Detalles Bibliográficos
Autores: El Mrabet, Said, Castro Arroyo, Miguel Ángel, Hurtado-Bermúdez, Santiago, Orta, M. Mar, Pazos, M. Carolina, Villa-Alfageme, María, Alba, María D.
Tipo de recurso: artículo
Fecha de publicación:2014
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/97151
Acceso en línea:http://hdl.handle.net/10261/97151
Access Level:acceso abierto
Palabra clave:Metallic canister
Bentonite
Radionuclide waste, 8 actinide
Lanthanide, Rare earth elements, Silicates, Hydrothermal treatment
Engineering barrier
Descripción
Sumario:An in depth knowledge and understanding of high activity radionuclide (HLRW) immobilization processes on the materials composing the engineered barrier (clay and metallic canister) is required to ensure the safety and the long-term performance of radioactive waste disposal procedures. Therefore, the aim of this study was to understand the mechanisms involved in the retention of Eu3+ by two components of the multibarrier system, the bentonite barrier and the canister. As such, a comparative study of the interaction of trivalent Eu3+, used to simulate trivalent actinides, with both bentonite and a metallic canister has been undertaken in this work. To this end, we designed a minireactor into which the bentonite was introduced and compacted. The minireactor-bentonite system was then submitted to a hydrothermal reaction with a 7.9×10-2M solution of Eu3+ at 300°C for 4.5days. SEM and XRD results revealed that both bentonite and the container were involved in the immobilization of europium by the formation of insoluble europium silicate phases. The presence of europium silicate adsorbed on the surface of the metallic canister indicates the competitive effect of both components of the engineered barrier (bentonite and metallic canister) in HLRW immobilization. These results suggested that the canister could play a role in the HLRW immobilization even during its corrosion process. © 2013 Elsevier Ltd.