Comparison of fundamental properties of Japanese bentonites as buffer material for waste disposal

Abstract

Bentonite is considered as one of the most promising buffer materials for geological disposal of radioactive waste in Japan. For selection of the primary candidate buffer materials, screening of commercially available bentonites is carried out. Eight kinds of bentonites are selected on the basis of published information. Then laboratory studies have concentrated on the following properties : mineralogical and chemical, mechanical, swelling, thermal and hydrologie properties. No significant difference is recognized between the properties of Japanese bentonites and those of MX-80,a reference buffer material in many countries. The influence of sodium chloride content on swelling and hydrologie properties is also studied.