Characterization of low- and medium-activity radioactive waste

In France, specifications for long-lived isotopes, which are critical for the safety of intermediate storage and disposal on surface sites, have been fixed. Because a number of these nuclides are pure beta or alpha emitters, a reliable radiochemical inventory of these isotopes requires a rather sophisticated preparative chemistry before radiation measurement. In view of the initial complexity of matrices for various types of waste, the preparation steps constitute a technological limit to the characterization. Therefore, practices eventually developed for synthetic waste may prove insufficient when applied to real samples. For isotopes with half-lives >105 yr, such as 99Tc and 129I, a physicochemical technique, inductively coupled plasma/mass spectrometry, constitutes an attractive alternative to radiochemical procedures. However, the request for high performance and limitations in sample activity does not allow preparative treatments and chemical separations from interfering species to be minimized