The radiolysis behaviors of TODGA-HOK by 4He2+ beam irradiation

N,N,N’,N’-tetraoctyldiglycolamide (TODGA) is one of most commonly-used extractant with excellent separation capacity in the disposal of high-level liquid waste (HLLW). In practical application, TODGA is exposed to strong ionizing irradiation which can induce nonignorable changes in its separation ability. Therefore, it is pivotal to investigate the radiolysis behavior of TODGA. In this work, the radiolysis behavior of TODGA-hydrogenated kerosene (TODGA-HOK) after exposure to external ⁴ He ²⁺ (α) beam from the CS-30 cyclotron accelerator was investigated quantitatively, as a function of absorbed doses, particle energies and absorbed dose rates. It has been demonstrated that the radiolysis ratio and the yields of radiolysis products of TODGA increased significantly with the increasing of the absorbed dose. Hydrogen, gaseous hydrocarbons, and eight major liquid radiolysis products could be quantitatively measured, of which N,N-dioctyl glycolamide was always the most abundant at every dose. Additionally, the radiolysis was influenced slightly by particle energy and absorbed dose rate in the range of 4 ~ 8 MeV and 7.8 ~ 31.2 kGy/min, respectively. This work has established a quantitative analysis method for the main radiolysis products of α-irradiated TODGA-HOK, providing important reference for the practical application of TODGA in HLLW.