abstract
- The oxidation of Np(V) by nitrous acid was investigated spectroscopically in 0.2 vi CMPO-1.4 M TBP-n-dodecane and the oxidation rate constant of Np(V) was estimated assuming the first-order reaction. By using the obtained oxidation rate constant as well as taking account of the Np(V) oxidation in aqueous phase and the distribution ratios of Np(V) and Np(VI) cited from literature, extraction kinetics of Np from 4 M nitric acid solution was calculated, and was compared with the extraction kinetics measured experimentally.