The advanced evaluation of phase analyses of corrosion products from different parts of VVER-440 steam generators via Mossbauer spectroscopy is our active and unique contribution in this area. The scientific works go over 25 years. The first period (mostly 80- ties) was important for improving Mossbauer technique. The benefit from this period is mostly in experience collection, optimization of measurement condition and evaluation programs improvement [5]. Unfortunately, not all specimens were well defined. Having in mind also different level of technique and evaluation procedures, it would be not serious to compare results from that period with the results obtained from measurement after 1998.