Electricité de France (EDF) has recently announced its intentions to extend the lifetime of some of its plants to 60 years which has lead to a large advance order of steam generators (SG) and therefore an intensive period of replacement. The detailed planning required during a shutdown and the industrial constraints for design and manufacturing necessitate the decision for a replacement to be taken a few years in advance. Predicting the end of life of a SG is principally governed by the level of degradation of the tube bundle which is largely dependent on the tube material and time in service. EDF carries out a risk assessment on the life of each SG based on the percentage of tubes plugged determined using statistical modeling that take into account factors such as the evolution and type of degradation. In addition, SG tube plugging rates have to be anticipated in advance to ensure the heat exchange capacity is within safety guidelines. This paper provides an overview of the status of active degradation growth rates and different calculation methods used at units with A600TT and A690TT tubing. Furthermore, their application on predicting the number of tubes to be plugged is illustrated. Finally, statistical models used to predict the evolution of different degradation types are also detailed.