The paper presents some approaches and methods for assessing and evaluation of different properties of equipment and pipelines metal of nuclear power plants during an operation such as a stress-strain state, a temperature and electrochemical effects. A problem statement for ageing management is considered for such metal properties of the heat – bearing agents. For this purpose, an observation of literature is provided for non – destructive testing (NDT) methods that have a correlation to a degradation factor defined by certain properties. There is has been made a case to apply NDT methods as a promising tool for an estimation and evaluation of degradation factor for a metal of potentially hazardous equipment. For this purpose there are proposed some rational and efficient solutions likes of acoustic methods based on structural – reverberation noise analysis, electromagnetic methods based on a coercive field strength deviation and electrical methods based on principles of potentiometry.