Speaker
Description
The long-lived radionuclide $^{129}I$ might be used as a tracer for assessing environmental contamination, estimating water age, and elucidating water circulation processes on Earth. Since $^{129}I$ is present in environmental samples at ultra-trace levels, highly sensitive analytical techniques are required for the accurate determination of its isotopic ratio with the stable isotope $^{127}I$. However, the ratio is not actively monitored in the Czech Republic, and the environmental background values for the country are unknown. Therefore, we address the existing data gap by developing an effective methodology to support future monitoring efforts. The radionuclide is predominantly generated by the fission of $^{235}$U in nuclear power plants. Moreover, the amount of $^{129}I$ in the environment has increased due to global nuclear fallout from major nuclear events, among which the most significant for the Czech Republic were nuclear weapon tests and the Chernobyl accident. Iodine is very mobile in the environment and is difficult to measure consistently due to its highly variable speciation. Nevertheless, by combining accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICP-MS), we can effectively determine the ratio of $^{129}I$/$^{127}I$. Hence, here we present our progress towards analyzing the ratio of $^{129}I$/$^{127}I$ in natural samples by MILEA AMS and ICP-MS collected at selected sites in the Czech Republic.