Predicting and Understanding the Behaviour of Minor Actinide Targets for Transmutation.

The irradiation behaviour of minor actinide targets containing high concentrations of minor actinides (MA) is not yet well understood, partly because of a lack of such experiments and partly due to the fact that their physical and thermodynamic properties are not well known. By a systematic review and analysis of the literature, the required quantities have been extrapolated/approximated and the expected thermal behaviour is described. In addition the effects of the chemical changes in the fuel, resulting from the 'chemical revolution' taking place in the transmutation process, are described by chemical thermodynamic techniques. Based on these calculations, different target concepts such as (U,MA)O2, (Zr,Y,MA)O2, Mo+(Zr,Y,MA)O2 and MgO+(Zr,Y,MA)O2 are discussed.JRC.E-Institute for Transuranium Elements (Karlsruhe