Important components in nuclear fission power plants are the nuclear fuel containing rods, meter long tubes made of Zr-based alloys. The main drawback of the Zr-based alloys are redox reactions with steam, with production of H2, as it happened in Fukushima. Following this accident, several Accident Tolerant Fuels (ATF) materials have been proposed and SiC fiber reinforced SiC matrix composites (SiC/SiC) are considered very promising materials for safe fission reactors because, in case of accidents, they do not have redox reactions with production of H2. However, SiC/SiC must be joined to obtain meter long tubes and their joining is still an issue: the aim of this final project is to help in the selection of some joining materials for these applications.