Expansion control for cementation of incinerated ash

Nakayama, Takuya  ; Suzuki, Shinji; Hanada, Keiji; Tomioka, Osamu ; Sato, Junya ; Irisawa, Keita  ; Kato, Jun ; Kawato, Yoshimi; Meguro, Yoshihiro  

A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was kneaded with a cement material and water, H generation began immediately just after the kneading, H bubbles pushed up the kneaded muddy material and an expanded solidified form was obtained. In this study, we tried to control H generation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded.