ADVANCES ON BUFFER/BACKFILL PROPERTIES OF HEAVILY COMPACTED GAOMIAOZI BENTONITE

摘要

Compacted bentonite is considered as buffer/ backfill materials for geological disposal of high-level radioactive wastes in many countries. Through a national screening and comparison, GMZ bentonite is selected as the first choice of Chinese buffer materials for high-level radioactive waste repository. Many studies were conducted on GMZ bentonite, however, its still in the primary stage compared with other candidate bentonites. In order to better orientate the future research work, the progress on researches of GMZ bentonite was summarized, which consist of studies on mineralogy and chemical composition, mechanical properties, hydraulic behavior, swelling behavior, thermal conductivity, microstructure and volume change behavior. Based on analysis of the current studies, the key issues to be explored in the future were also proposed, that is the influence of temperature on behavior of the GMZ bentonite; the migration law of nuclide in compacted bentonite and sealing properties of GMZ bentonite based materials under coupled T-H-M-C conditions.