On the basis of the previously developed general model of prediction of fracture toughness of irra diated austenitic materials, a new, less conservative, model is proposed. This model makes it possible to deter mine fracture toughness as a function of temperature and neutron dose individually for base metal and weld metal in the test temperature range from 20 to 350°C. The input data for the model are the fracture toughness of the material in the initial state and yield stress and ultimate strength of the material as a function of tem perature and neutron dose.