Radiolytic behaviour of a TODGA based solvent under alpha irradiation

In this work the radiolytic stability of a TODGA based solvent has been investigated in alpha radiolysis measured by solvent extraction distribution ratios. Solutions of TODGA in alkane diluents have been subjected to ²⁴⁴Cm α-irradiation in the presence of nitric acid (0.5 M) and analysed using radiometric techniques to determine their rates of radiolytic degradation. It was shown that alpha radiolysis, similarly to external gamma irradiation, produces an exponential decrease of the free TODGA concentration of the organic solvent as the solvent is degraded with increasing absorbed alpha dose. The degradation constant, obtained from the exponential decrease, indicates that the free TODGA concentration is halved with every 1.0 MGy deposited to the solvent from internal alpha decay. This result could be useful information when dealing with high activity actinide solutions in TODGA based solvent extraction systems. (author)