Electromagnetic characterization of material degradation due to neutron irradiation

Most of the materials used in practice show degradation due to fatigue, i.e. cyclic loading. Very often other degradation mechanisms like corrosion and in the high temperature regime also creep are superimposed. In the primary circuit of nuclear power plants the material is additionally exposed to neutron irradiation. According to the licensing conditions the main focus is on the pressure vessel material. The contribution describes measurement results collected at surveillance programme specimen of different nuclear power plants in different European countries. The set of Charpy specimen was measured in the hot cell of the research reactor in Petten in the Netherlands. Electromagnetic non-destructive testing techniques were applied for characterization.