The change in SiC properties under neutron irradiation is being experimentally assessed but it is actually far from being well understood. Using Molecular Dynamics (MDCASK-DENIM/LLNL), we show the existence of recombination barriers (metastable defects), and how they affect the cascade analysis. Displacement cascades have been systematically studied and the different role of both sublattices examined. Low-temperature amorphization by damage accumulation has been successfully simulated using MD in accordance with experiments, allowing the understanding (not possible from experiments) of the atomistic sequence of damage. We are also developing new methodologies (tight binding MD) to prove the adequacy of the interatomic potential to describe energetic of configurations needed for diffusion in SiC. The neutron source from target is obtained with time resolution, together with responses after transport in the IFE reactor. The comparison of different primary knock-on atom (PKA) energy spectra from different fusion reactors is given, which is a basic information for displacement cascade analysis. Those spectra are a direct consequence of the neutron spectra in the material (depending on protection). Supported by recent work on atomistic level, the effect of pulsed irradiation was concluded. The time between pulses has a key role in the annealing process of defects. The comparison with average continuous irradiation, and the different behaviour for vacancies and interstitials, are highlighted.