Abstract

Iodine is retained in spent solvent [tributyl phosphate/odourless kerosene (TBP/OK)] from nuclear fuel reprocessing, which makes decontamination difficult. TBP/OK is a very complex matrix in which speciation of the low concentrations of iodine present is difficult. XANES spectroscopy is element-specific and relatively independent of the sample medium. The iodine K-edge XANES spectrum of a spent solvent sample from nuclear fuel reprocessing, containing 40 ppm total iodine, was obtained and compared with the XANES spectra of eight reference compounds containing iodine in oxidation states from −1 to +7. The spectrum of the solvent sample suggests that iodine is most probably present in the sample as an organoiodide species. However, molecular iodine has a very similar XANES spectrum and, because of the quality of the waste sample data, its presence cannot be completely excluded.