Performance assessment of a bentonite–sand mixture for nuclear waste isolation at the potential Akkuyu Nuclear Waste Disposal Site, southern Turkey

Abstract

This study assesses the geotechnical performance of a compacted bentonite–sand mixture with a bentonite content ranging from 15 to 30 % by weight to be used as a material component in a waste sealing system. Geotechnical laboratory tests such as compaction, falling head permeability, swelling, unconfined compression and shear strength tests were conducted to select an optimum mixture which eventually led to a recommendation to select an optimum bentonite–sand mixture possessing a bentonite content of 30 % for the isolation of underground waste disposal facilities. Bentonite–sand seal design was performed for the optimum seal selected as a function of the axial stress applied to the seal and seal length-to-radius ratio.