Hello everybody! My name is Luyaun Zhang and I’m a PhD-student at the NUTECH department at the Danish Technical University, DTU. My supervisor, Xiaolin Hou, managed to get me to work on the very interesting subject of I-129 here in Denmark. Iodine-129 is an artificial isotope that is produced in large quantities in nuclear reactors. Because iodine is an element that is very mobile and which has a very complicated chemistry some amount of the iodine-129 escapes the power reactors and reach the environment through air and water. Most of it comes from the industrial units used to handle the used nuclear fuel, they are called reprocessing plants and we can find them in France and in UK. My task as a PhD-student is to look closer at atmospheric iodine since the forms of iodine determines its mobility.