Radiolysis of amidic extractants for the separation of actinides

Sugo, Yumi

In order to reduce the long-term environmental burden of high-level radioactive waste (HLW), we have developed an efficient extractant, -tetraoctyldiglycolamide (TODGA) for the recovery of long-lived actinides from spent nuclear fuel. For the purpose of the application of TODGA to the extracting process in high radiation fields, the radiolysis of TODGA in -dodecane was investigated by the irradiation with -rays and electron pulses. It was obvious that -dodecane had a sensitization effect on the radiolysis of TODGA, owing mainly to a charge transfer from radical cations of -dodecane to TODGA molecules in the primary process. In the actual partitioning process of HLW, the organic extractant will be exposed to -particles. -Radiolysis of TODGA in -dodecane was also investigated by the irradiation with helium ion beam. It was found that the radiation chemical yield for the degradation of TODGA by helium ion beam irradiation was less than that by -rays irradiation. Because the radical cations of -dodecane, which contribute to the charge transfer reaction, decrease by recombination in track by high LET radiations such as -particles.