Characterization of bentonite, vermiculite and soil as potential materials to compose the natural barriers in a near-surface repository

Daisy Mary Marchezini dos Santos; Samara Alves Barroso; Thaís Braga Teixeira; Clédola Cássia Oliveira de Tello

doi:10.15392/2319-0612.2022.1950

Authors

Daisy Mary Marchezini dos Santos Centro de Desenvolvimento da Tecnologia Nuclear
Samara Alves Barroso
Thaís Braga Teixeira
Clédola Cássia Oliveira de Tello

DOI:

https://doi.org/10.15392/2319-0612.2022.1950

Keywords:

bentonite, soil, expanded vermiculite, repository, radioactive waste

Abstract

The use of nuclear technology is growing in Brazil, where it is possible to carry out the entire nuclear fuel cycle. This technology generates radioactive waste that must be treated before being released into the environment or stored in suitable facilities. Then, the first national repository - CENTENA - will be implemented, where all low and intermediate level radioactive waste generated in Brazilian territory will be safely stored. One of the barriers that will compose the repository will be composed of natural materials such as soils and clays, the latter for having a high adsorption and cation exchange capacities and swelling potential. The purpose of the article is to show the research carried out in Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) with natural materials aiming their use in natural barriers. Four materials were characterized: CDTN soil, this soil with bentonite, expanded vermiculite and bentonite, using the clay characterization protocol. Primary mineralogical, physical and chemical analyzes were performed, such as X-ray diffraction, scanning electron microscopy, particle size distribution, specific surface area and cation exchange capacity. The results showed that these clays are potentially candidates for composing CENTENA's natural barriers.

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Author Biography

Daisy Mary Marchezini dos Santos, Centro de Desenvolvimento da Tecnologia Nuclear

Daisy Marchezini é aluna de Doutorado em Ciência e Tecnologia das Radiações, Minerais e Materiais do Programa de Pós-Graduação do Centro de Desenvolvimento da Tecnologia Nuclear desde 2017. Ela recebeu seu mestrado em 2017 pela mesma instituição. Seus interesses de pesquisa incluem rejeitos radioativos e seus depósitos. Atualmente faz parte do quadro de colaboradores do setor SEGRE/CDTN.

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