Sorption Modeling Study on Rock and Bentonite (OECD/NEA Sorption Project)

Jintoku, Takashi; Shibata, Masahiro ; Yoshida, Yasushi*; Suyama, Tadahiro*

We attended the OECD/NEA Sorption Project in which sorption modeling study and applicability study for sorption experimental results on minerals was held. In this study, JNC selected the sorption modeling of Ni, Np onto Montmorillonite and U onto Weathered Shist, adopted the surface complexation model and/or ion exchange model, and carried out modeling for the experimental results by using the fitting procedure. In this procedure, PHREEQC geochemical calculation code was used. Based on the modeling results which can explain experimental results, the equilibrium constants were fixed.Following the modeling, the applicability study which applies the modeling results to other sorption experiments presented that the errors of Kd value between them were within approximately one order. For the future, validation procedures for this model are needed.