PROCESSES AFFECTING THE UPTAKE OF RADIOACTIVE SPECIES INTO THE ENVIRONMENT

Information on the source term and the nature of radionuclide species as well as their release rates, interactions and transformation proces ses that influence the mobility, biological uptake and transfer of rad ionuclides into the food chain, is essential for the assessment of sho rt-term and long-term consequences of radionuclides released into diff erent ecosystems. The mobility and transfer of radionuclides in an eco system is highly dependent on the physico-chemical form of the deposit ed or released radionuclides. The importance of investigating the form ation of radionuclide species and the processes influencing the mobili ty and biological uptake are considered here. As a major fraction of t he deposited radionuclides in the vicinity of the Chernobyl reactor wa s associated with uranium oxide fuel particles. Most emphasis will be put on the impact of radioactive particles entering different ecosyste ms.