Abstract
The decontamination work implemented after the Fukushima Daiichi Nuclear Power Plant accident generated the removed soil containing radioactive cesium. This study assumed that the removed soil would be disposed of in a coastal disposal facility, and the geomaterial used for the sealing layer of the coastal disposal facility was developed. The necessary sealing performance of the geomaterial was examined, and the effects of mixing of bentonite, sand, and zeolite on marine clay were studied. Bentonite was added for improving the sealing performance. Sand was added for improving the low compressibility of the sealing material and the workability by increasing the coefficient of consolidation. Zeolite was added for improving the adsorption of cesium. The effective porosity obtained by the column test in consideration of the flow velocity in pore space was the same as the porosity obtained by the consolidation and seepage test. The hydraulic conductivity for flow in pore was increased by the addition of sand but not by the addition of zeolite.
