Measurement of the fracture toughness properties of irradiated materials presents many difficulties because of the limited volume of the specimens. One solution to this problem lies in the use of the fracture energy criterion, which is valid for high plastic deformation. The Absorbed Specific Energy Until Fracture (ASPEF) criterion was used for evaluating irradiation research results and a correlation was found between this criterion and the fatigue crack propagation rate on nonirradiated steels, thereby providing a basis for using ASPEF to evaluate surveillance results.