Experimental study of alteration of bentonite coexisting iron material

Sasamoto, Hiroshi   ; Ishii, Tomoko*; Sato, Hisao*; Sazarashi, Masami

It is necessary to evaluate the alteration behavior of buffer material by interactions of overpack (iron) and buffer (bentonite) materials for geological disposal of high level radioactive waste. In the present study, laboratory experiments were carried out for the better understanding of phenomena caused by iron-bentonite (smectite) interactions. Before conducting the experiments, literature survey was performed to summarize the existing knowledge about iron-bentonite interactions and to identify the dominant factors affecting the alteration behavior. As the results of experiment, experimental conditions caused remarkable alteration, secondary minerals suggested as alteration product, different behavior of alteration between batch and compacted systems etc. were revealed.