Evaluation of the density distribution in bentonite-sand buffer blocks manufactured by floating die press method

For the safe disposal of high-level radioactive waste, several performances of the compacted buffer block are required, such as low hydraulic conductivity, high thermal conductivity, adequate swelling pressure, and good mechanical properties. Furthermore, it is well recognized as the performance of these buffers is highly correlated with the density of buffer blocks. Therefore, it is an essential task to fabricate the compacted buffer block with a homogenous density distribution. In this study, the manufacturing characteristics of bentonite-sand buffer were evaluated to identify the required density relationship in accordance with the pressure of floating die press and the homogeneity of the dry density distribution in the buffer blocks.