CONCEPT OF HYDRIDE FUEL TARGET SUBASSEMBLIES IN A FAST-REACTOR CORE FOR EFFECTIVE TRANSMUTATION OF MA

U-Th-Zr alloys with four different compositions were hydrogenated and examined for their hydrogen holding capacities, microstructural and ha rdness changes with irradiation and thermal diffusivities. Considerabl y high hydrogen capacity was confirmed up to about 1173 K. A certain d egree of irradiation stability was observed, and relatively high therm al diffusivity was ascertained for these hydrogenated ternary alloys. Based on these results, a new concept for effective transmutations of MA was proposed, where target assemblies containing Np and Am in hydro genated form are loaded in a fast reactor core. This concept has a gre at potential to achieve the best transmutation of MA with improvement of safety characteristics in a fast reactor core. (C) 1998 Elsevier Sc ience S.A.