Thermal Conductivity of Compacted GO-GMZ Bentonite Used as Buffer Material for a High-Level Radioactive Waste Repository

Abstract

In China, Gaomiaozi (GMZ) bentonite serves as a feasible buffer material in the high-level radioactive waste (HLW) repository, while its thermal conductivity is seen as a crucial parameter for the safety running of the HLW disposal. Due to the tremendous amount of heat released by such waste, the thermal conductivity of the buffer material is a crucial parameter for the safety running of the high-level radioactive waste disposal. For the purpose of improving its thermal conductivity, this research used the graphene oxide (GO) to modify the pure bentonite and then the nanocarbon-based bentonite (GO-GMZ) was obtained chemically. The thermal conductivity of this modified soil has been measured and investigated under various conditions in this study: the GO content, dry density, and water content. Researches confirm that the thermal conductivity of the modified bentonite is codetermined by the three conditions mentioned above, namely, the value of GO content, dry density, and water content. Besides, the study proposes an improved geometric mean model based on the special condition to predict the thermal conductivity of the compacted specimen; moreover, the calculated values are also compared with the experimental data.

Experimental Study on the Thermal Conductivity of Compacted SPV200 Bentonite

“…Cho (2011) considered the thermal conductivity of the compacted bentonite as a weighted sum of the thermal conductivity of the components [23]. A modified geometric mean model was suggested by Chen (2018) based on multi-parameters (e.g., saturation, dry density, particle density) to predict the thermal conductivity of GO-GMZ bentonite [24]. Machine-learning methods were used by Bang (2020) to predict a thermal conductivity model, while the results of the Gaussian process regression with exponential kernel and the ensemble show the best results [25].…”

Adsorption Property of Pb(II) by the Laterite‐Bentonite Mixture Used as Waste Landfill Liner

“…However, most of the literatures concentrate on the property of pure bentonite and natural clay [19][20][21][22][23]. Scarce literatures discuss the property, especially the adsorption capacity of lateritebentonite mixture other than its hydraulic conductivity [24,25] and shear strength [26].…”