Special Element Transmutation in the Fuel Cycle of the XADS Preliminary Core

The potentially large subcriticality margin of an ADS should allow the introduction of very significant quantities of waste products such as Minor Actinides and Long-Life Fission Products, which generally have a negative impact on the safety criteria of a standard core. The present work is inserted in the framework of the XADS project. Its purpose is to make an initial analysis, using deterministic methods (ERANOS modular system), of the behaviour of a special element introduced for a period of 900 days fuel cycle in the XADS preliminary core. For the time being, the special element is the one proposed by Argonne National Laboratory where the fuel (composed by significant quantities of Minor Actinides and Tc-99) is metallic and inserted in a zirconium matrix. For each fuel ring, analyses of reactivity loss per cycle and transmutation rate for each nuclide have been obtained. A spectrum analysis at Beginning and End of Cycle, as well as a comparison with the spectrum of an adjacent fuel element have al so been obtained.