방사성폐기물학회지 (Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT))

  • 제22권1호
  • /
  • Pages.9-16
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  • 2024
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  • 1738-1894(pISSN)
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  • 2288-5471(eISSN)
한국방사성폐기물학회 (Korean Radioactive Waste Society)
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Evaluation of Thermal Properties for the Bentonil-WRK Bentonite

  • 투고 : 2023.11.15
  • 심사 : 2024.01.10
  • 발행 : 2024.03.30
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초록

The bentonite buffer material is a crucial component in an engineered barrier system used for the disposal of high-level radioactive waste. Because a large amount of heat from the disposal canister is released into the bentonite buffer material, the thermal conductivity of the bentonite buffer is a crucial parameter that determines the design temperature. At the Korea Atomic Energy Research Institute (KAERI), a new standard bentonite (Bentonil-WRK) has been used since 2022 because Gyeongju (KJ) bentonite is no longer produced. However, the currently available data are insufficient, making it essential to investigate both the basic and complex properties of Bentonil-WRK. Thus, this study evaluated its geotechnical and thermal properties and developed a thermal conductivity empirical model that considers its dry density, water content, and temperature variations from room temperature to 90℃. The coefficient of determination (R2) for the model was found to be 0.986. The thermal conductivity values of Bentonil-WRK were 1-10% lower than those of KJ bentonite and 10-40% higher than those of MX-80 bentonites, which were attributable to mineral-composition differences. The thermal conductivity of Bentonil-WRK ranged between 0.504 and 1.149 W·(m-1·K-1), while the specific heat capacity varied from 0.826 to 1.138 (kJ·(kg-1·K-1)).

키워드

과제정보

This research was supported by the Nuclear Research and Development Program of the National Research Foundation of Korea (2021M2E3A2041351), and Institute for Korea Spent Nuclear Fuel and National Research Foundation of Korea (2021M2E1A1085193).

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