α-Radiolysis Behaviour of 30%TBP-Kerosene-HNO₃ Extraction SystemⅠ. Analysis of DBP and MBP in Radiolytic Products

Gas chromatography has been used to determine the concentration of dibutyl phosphate (DBP) and monobutyl phosphate (MBP) produced from α-radiolysis due to ²³⁸Pu in the  30%TBP-kerosene HNO₃ extraction system. The effects of back-extractant, stripping conditions and concentration of plutonium were studied on the concentration of DBP and MBP. Moreover, the effects of total dose, nitric acid concentration, dose rate and dilutes on the concentration of DBP and MBP were investigated. The results show that the concentration of DBP and MBP increases with absorbed dose and dose rate. When the absorbed dose is 5×10⁴ Gy and the absorbed dose rate is 73.7 Gy/min, among n-dodecane, hydrogenation kerosene and special kerosene, the yields of DBP are 4.45×10^-2 mol/L，4.44×10^-2 mol/L，4.35×10^-2 mol/L，respectively, and the yields of MBP are 3.52×10^-3 mol/L, 3.52×10^-3 mol/L，3.50×10^-3 mol/L, respectively. When the absorbed dose increases to 5×10⁵ Gy, the concentration of DBP and MBP in three dilutes are approximately equal. When the absorbed dose is 5×10⁴ Gy, the concentrations of DBP and MBP in system of α-radiolysis are 5.57×10^-2 mol/L and 5.10×10^-3 mol/L respectively, the corresponding concentration of DBP and MBP in system of γ-radiolysis are 2.50×10^-3 mol/L and 3.14×10^-4 mol/L respectively, the concentrations of DBP and MBP produced from α-radiolysis of extraction system are obviously greater than those from γ-radiolysis of system at same dose.