Effect of 239Pu α-radiation on its extraction from nitric acid solutions with a 30% solution of tri-n-butyl phosphate in Isopar-M

Abstract

Extraction of ²³⁹Pu from 4 M НNО₃ with an HNO₃-saturated 30% solution of tri-n-butyl phosphate (TBP) in Isopar-M in the cyclic mode was studied. As a result of four-month contact with an aqueous НNО₃ solution containing 0.11 M Pu(IV), the organic phase absorbed the total α-radiation dose of 380 kGy. The fraction of the residual Pu in the organic phase after stripping increases by a factor of 5–7 as the absorbed dose is increased from 32 to 263 kGy. The residual concentration of Pu in the organic phase after 45–50 stripping cycles (which corresponds to the irradiation dose with accelerated electrons of 120–150 kGy) increases by a factor of 3–4. The Pu distribution ratio in the extraction step in the cyclic mode varies only slightly.