NAGASAKI Sinya School of Eng., Univ.of Tokyo, Associate Professor, 大学院・工学系研究科, 助教授 (20240723)
TANAKA Satoru School of Eng., Univ.of Tokyo, Professor, 大学院・工学系研究科, 教授 (10114547)
安 俊弘 東海大学, 工学部, 助教授 (10201906)
岡本 毅 東京大学, 工学部, 教務職員 (40114425)
|Budget Amount *help
¥12,600,000 (Direct Cost : ¥12,600,000)
Fiscal Year 1995 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1994 : ¥4,400,000 (Direct Cost : ¥4,400,000)
Fiscal Year 1993 : ¥7,000,000 (Direct Cost : ¥7,000,000)
Waste management of high revel waste disposal is the hopeful method to prevent isolate radioactive waste disposal from human beings. The scenario, however, is concluded on the assumptions that the properties of engineering barrier is unique for a long time. In fact, it is known that smectites change into illites by ion-exchange with cation in the ground water.
As a result of this research, The effect that smectites change into illites, on migration in the bentonite can be evaluated. Results are summarized as follows.
(1) Chemical conditions, i.e.pH,oxidation-reduction potential and concentration of carbonate acid of the water in the bentonite porosity, were experimentally measured before worsening and it can be edited that those values agree with the simulation results. It is made clear that americium change into pseudo-colloids by attaching to microsperes from bentonite. By supposing pseudo-colloids, that experimentally measured effect on adsorb of americium can be explained theoretically.
(2) By exprimentally measuring sorption distribution coefficient of smectites, illites, and mixture and using these measured data and Altarner model, a model, by which the change of properties can be quantitatively explained, was made. Furthermore, By measuring sorption distribution coefficient for smectites, illites, and mixture with another mixing ratio, the properties of these elements were found out.
(3) According to results of (1) and (2), a model of radionuclide migration was made, considering change of bentonite as time passed. The results of simulation show that the change of bentonite property dependant on time quantitatively makes effects on the migration in bentonite.