The master curve approach for assessing the fracture toughness of a sampled irradiated material has been gaining acceptance around the world. This direct measurement approach is preferred over the correlative and indirect methods used in the past to assess irradiated reactor pressure vessel (RPV) integrity. The master curve methodology already has been or is being assimilated into the ASME Boiler and Pressure Vessel Code, ASTM standards, USNRC regulations, German regulations (KTA 3203) and IAEA PTS guidelines for WWER reactors, as well as the VERLIFE “Unified Procedure for WWER Component Lifetime Assessment” and other industry guidance documents governing RPV integrity analysis. As this report was prepared using the results of many research projects and experiments, these guidelines for application will be used for a long time to evaluate and assess the residual life of RPVs.