Radioanalysis of ultra-low level radionuclides for environmental tracer studies and decommissioning of nuclear facilities

Determination of long-lived radionuclides is critical for environmental radioactivity investigation, environmental processes studies and decommissioning of nuclear facilities. This paper summarizes main progress in the radiochemical analysis in our laboratories in the past years for determination of ultra-low level radionuclides in the environment using chemical separation combined with mass spectrometry measurement. The analytical methods for determination of ultra-low level ¹²⁹I and its chemical species in various environmental samples are highlighted. The methods developed in our laboratories for characterization of decommissioning waste, especially the methods for the determination of difficult-to-measure radionuclides using sequentially chemical separation and radiometric measurement are also briefly presented. This is also a part of the Hevesy Medal award lecture in the RANC2019 conference.