Investigation of the various properties of several candidate additives as buffer materials

• Published in: Nuclear engineering and technology Vol. 55; no. 3; pp. 1191 - 1198
• Main Authors: Lee, Gi-Jun, Yoon, Seok, Kim, Taehyun, Chang, Seeun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2023; Elsevier; 한국원자력학회
• Subjects: Additives; Bentonite buffer; Engineered barrier system; THMC properties; 원자력공학; Bentonite buffer; Additives; THMC properties; Engineered barrier system
• ISSN: 1738-5733; 2234-358X
• DOI: 10.1016/j.net.2022.11.017

Bentonite buffer material is a critical component in an engineered barrier system (EBS) for disposing high-level radioactive waste (HLW). The bentonite buffer material protects the disposal canister from groundwater penetration and releases decay heat to the surrounding rock mass; thus, it should possess high thermal conductivity, low hydraulic conductivity, and moderate swelling pressure to safely dispose the HLWs. Bentonite clay is a suitable buffer material because it satisfies the safety criteria. Several additives have been suggested as mixtures with bentonite to increase the thermal-hydraulic-mechanical-chemical (THMC) properties of bentonite buffer materials. Therefore, this study investigated the geotechnical, mineralogical, and THMC properties of several candidate additives such as sand, graphite, granite, and SiC powders. Datasets obtained in this study can be used to select adequate additives to improve the THMC properties of the buffer material.