Transport and Release Properties of Gaseous and Volatile Fission Products in Nuclear Fuels – Relevance and State of Art of Their Characterisations in the Laboratory

Introduction Safe operation of a nuclear reactor depends to a large extent on the behaviour of different fission products generated within the fuel. While most of the fission products settle down as dissolved state in the fuel matrix or as separate phases, the gaseous products, xenon(Xe), and krypton(Kr), and the volatile products, iodine(I), tellurium(Te), cesium(Cs), and rubidium(Rb), undergo transport and redistribution in the fuel pin [1]. The redistribution leads to significant release of the gases and volatiles from the fuel, and accumulation of the released species at the boundary regions with clad (Fig.1).