Dissolution Behavior of Uranium Oxides with Supercritical CO2Using HNO3-TBP Complex as a Reactant
| Autor: | Osamu Tomioka, Zenko Yoshida, Yoshihiro Meguro, Youichi Enokida, Ichiro Yamamoto |
|---|---|
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Journal of Nuclear Science and Technology. 38:1097-1102 |
| ISSN: | 1881-1248 0022-3131 |
| DOI: | 10.1080/18811248.2001.9715141 |
| Popis: | Dissolution behavior of U3O8 and UO2 using supercritical CO2 medium containing HNO3-TBP complex as a reactant was studied. The dissolution rate of the oxides increased with increasing the HNO3/TBP ratio of the HNO3-TBP complex and the concentration of the HNO3-TBP complex in the supercritical CO2 phase. A remarkable increase of the dissolution rate was observed in the dissolution of U3O8 when the HNO3/TBP ratio of the reactant was higher than ca. 1, which indicates that the 2:1 complex, (HNO3)2TBP, plays a role in facilitating the dissolution of the oxides. Half-dissolution time (t½ ) as an indication of the dissolution kinetic was determined from the relationship between the amount of uranium dissolved and the dissolution time (dissolution curve). A logarithmic value of a reciprocal of the t½ was proportional to the logarithmic concentration of HNO3, CHNO3, in the supercritical CO2. The slopes of the (l/t½ ) vs. ln CHNO3 plots for U3O8 and UO2 were different from each other, indicating that the reaction ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|