The displacement, helium production, and hydrogen production rates in five candidate materials for controlled thermonuclear reactors (CTR) (Type 316 stainless steel, molybdenum, columbium, vanadium, and sintered aluminum product) were calculated for seven potential irradiation facilities. The damage rates were calculated for two fast fission reactors (fast flux test facility and Experimental Breeder Reactor-II), two thermal reactors (high flux isotope reactor and experimental test reactor), two accelerator neutron sources (Los Alamos Meson Production Facility and rotating target neutron source), and a typical CTR blanket. It was found that while fission reactors can easily duplicate displacement damage rates typical of CTR first walls, they fall short, sometimes by several orders of magnitude, of duplicating the helium and hydrogen production rates. The one exception to the latter statement is that helium production in stainless steel, due to the 59Ni production, can even be higher in thermal fission reactors than in CTR. Accelerator sources produce damage which is more like that in CTR, but the absolute magnitude in current facilities is too low by at least an order of magnitude. It is concluded that the high flux isotope reactor is currently the best neutron facility to simulate fusion reactor damage.