A comparative study using liquid scintillation counting and X-ray spectrometry to determine ~(55)Fe in radioactive wastes

摘要

The radionuclide ~(55)Fe was determined in samples of radioactive wastes from the water cleanup system of the IEA-R1 nuclear research reactor. In order to validate the results, the ~(55)Fe activity concentration was measured in eight waste samples and in six simulated samples containing the most important interfering radionuclides. A simple method was employed to separate and purify ~(55)Fe from other radionuclides present in these samples, combining co-precipitation with ammonium hydroxide and purification with anionic ion-exchange resin, which enables ~(55)Fe to be quantified either by liquid scintillation counting (LSC) or by X-ray spectrometry using a low-energy germanium spectrometer (LEGe). Both measurement methods were used so that the separation and purification process could be confirmed by comparison of spectra with and without the utilization of anionic ion-exchange resin. Activity and interferences were compared in the results obtained from LSC and LEGe measurement methods.