High-level radioactive waste (HLW) disposal is considered to constitute a disposal system within a deep rock mass using deep geological repository. A deep geological disposal system has an engineered barrier system (EBS) consisting of canisters, buffer material, and backfill material. Among these items, the buffer material protects a canister from groundwater inflow and prevents radionuclide outflow. It is an also very important factor for evaluating the stability of a disposal system in which heat is propagated from the canisters. The aim of this study was to evaluate the thermal and hydraulic properties of Gyeongju bentonite, a buffer material from Korea. The thermal conductivity and hydraulic conductivity of Gyeongju bentonite were measured according to different degrees of saturation and to dry density. The whole process is based on the temperature change induced in the disposal environment. The thermal conductivity increased as temperature increased, and as did the temperature effect with high initial degree of saturation. Additionally, the hydraulic conductivity also increased as temperature did, and decreased with high dry density. After the process of heating and cooling, the thermal and hydraulic conductivity of the bentonite presented irreversible changes.

高放射性废物（HLW）处置被认为是使用深部地质处置库的深部岩体中的处置系统。一个深层地质处置系统具有一个由罐，缓冲材料和回填材料组成的工程屏障系统（EBS）。在这些物品中，缓冲材料可保护滤罐免于地下水流入，并防止放射性核素流出。对于评估从罐中散发热量的处置系统的稳定性，这也是一个非常重要的因素。这项研究的目的是评估韩国缓冲材料庆州膨润土的热和水硬性能。庆州膨润土的热导率和水导率根据饱和度和干密度的不同进行了测量。整个过程基于处理环境中引起的温度变化。导热系数随着温度的升高而增加，并且温度效应具有较高的初始饱和度。另外，水力传导率也随温度升高而增加，并随高干密度而降低。在加热和冷却过程之后，膨润土的导热率和水力传导率呈现不可逆的变化。