Spectroscopic characterization of aqueous Am (III) species

Minor trans-uranic (TRU) radionuclides including Am in spent nuclear fuels are the major concerned long-lived radionuclides in the high-level radioactive waste managements. Understanding their physicochemical interactions in groundwater systems is essential for the safety assessments of the high- level radioactive waste managements. In this study, we directly characterized the spectroscopic properties Am³⁺ and its hydrolysis products progressively formed upon increase in the pH conditions. Temperature-dependent changes of the spectroscopic properties will be also discussed in relation to the species distribution. We demonstrate here that luminescence of Am(III) can be useful in the study of Am speciation. pH- dependent luminescence spectral changes were observed along with increased lifetimes. Our results suggest that hydrolyzed Am(III) species have distinguished luminescence properties and can be resolved from the TRLFS studies.