In this paper a review of knowledge on materials under irradiation will be presented in comparison with requirements for specific purposes in inertial fusion energy (IFE) reactors. The first assessment need to be flux and fluence of the irradiation particles (neutrons, gammas, charged particles or radiation) depending of present ideas on reactors concepts. From that response the activation of the materials (critical for safety and environmental considerations) will be obtained and the identification of energy spectra of secondary damage particles will be obtained and presented in this paper. The synergy with magnetic fusion research will be highlighted and the present experiments of irradiation will be analyzed in order to have a comparative idea of usefulness of such connection. In that line a review of state of-art of design for International Fusion Materials Irradiation Facility (IFMIF) need to be commented to know the final use for IFE purposes of such systems. The present tools of multiscale modeling together with ad hoc experiments and final macroscopic responses under irradiation will be presented in order to justify the confidence in their predictive capability to materials design. Dislocation dynamics has been used to study the interaction of stacking fault tetrahedra with partial dislocation successfully using Lawrence Livermore National Laboratory (LLNL) codes DD3D and PARADIS. A new parallel code to simulate diffusion of defects by kinetic Monte Carlo (kMC) has been generated that will allow to extend the process in microscopy to very large lifetimes. We have identified and characterized defects in fused silica using several methodologies and effects of H are being studied To fully simulate the behavior of chemical forms of tritium, we have developed and applied a methodology that includes diffusion and deposition processes in the soil and vegetables, the penetration in the underground, re-emission and later conversion to organic tritium. Two well-differentiated studies, deterministic and probabilistic, have been considered for some environment. The very detailed process of re-emission has shown to be very important.