Recovery of Protactinium from Irradiated Thorium Nitrate by Solvent Extraction

The extractive recovery of protactinium from irradiated thorium nitrate as applied to the conditions of the fusion neutron source blanket was studied using n-octanol and diisobutylcarbinol as extractants. The degree of recovery of 233Pa from a solution of irradiated thorium nitrate (600 g/dm3) in 3 М nitric acid in one contact exceeded 80%, and the separation factors from uranium and thorium were higher than 600 and 130000, respectively. To reduce the content of 232U in 233U (below 5 ppm), a flowsheet involving short irradiation of thorium nitrate and continuous extractive recovery of protactinium was suggested.