Fission Product Chemistry in Oxide Fuels

This chapter provides an overview of the chemical state of the actinide/fission product system that arises in irradiated thermal and fast reactor oxide fuels. Experimental techniques for studying minor phase formation in irradiated fuels are reviewed. Thermodynamic computational methods are discussed in relation to the prediction of the chemical speciation of the fission products and their influence on the fuel oxygen potential with fuel burnup. For water-cooled reactors, the consequences of defective fuel operation on fuel oxidation kinetics, as it bears on the fission product release behavior, are discussed. In addition, release behavior during high-temperature reactor accidents is also reviewed taking into account that the fuel and fission products may further interact with the structural materials.