The JANNUS Saclay facility results from the coupling of three accelerators: a 3-MV Pelletron “Épiméthée,” a 2-MV Tandem “Japet,” and a 2.5-MV Van de Graaff “Yvette.” The Joint Accelerators for Nanosciences and Nuclear Simulation (JANNUS) Orsay facility is composed of a 200-kV TEM connected with two accelerators: a 2-MV Van de Graaff/tandem “Aramis” and a 190-kV ion implanter “Irma.” In the first part of this paper, after a brief description of both facilities, the performances allowed in terms of suppress the irradiation configuration will be presented and discussed. Then, we will illustrate the experiments that have been yet carried out involving accumulation damage (dose per atom (dpa)) and simultaneous He or He and H ion-beam irradiation. These experiments mainly concern pure α-Fe, model Fe–Cr alloys and Fe–Cr oxide-dispersion-strengthened (ODS) alloys. Finally, we will conclude by showing the near-future prospects scheduled to study He (+H)/dpa synergistic effects on ODS alloys and advanced ceramics and composites.