Mechanism of Redox Reactions of Actinide Ions on Solid/Water Interface

Tanaka, Satoru*; Nagasaki, Shinya*; Nakata, Kotaro*; Oda, Takuji*; Kameda, Jun*; Kamei, Gento; Tachi, Yukio

JNC TY8400 2003-008, 88 Pages, 2003/05

JNC-TY8400-2003-008.pdf:1.29MB

Redox reactions between Cr(VI) and iron(II) chloride (FeCl2) and those between Cr(VI) and magnetite (Fe(II)1Fe(III)2O4) were observed as a preliminary study. According to the experimental results, it was suggested that the redox reactions were promoted more than the amount of Fe(II) on magnetite surface because of electron transfer from internal Fe(II) to magnetite surface. The results were quantitatively supported from quantum chemical calculations. Redox reactions between Np(V) and magnetite and the reduction of Np to tetravalent were observed, while those between Np(V) and FeCl2 were not observed obviously. It was observed that the reactions were promoted rapidly when the magnetite / solution ratio and the temperature were high, and the rate constant of the reactions was obtained. Furthermore, it was found that hydrogen gas and hydrogen ion were generated with crushing the quartz in an inert gas atmosphere.