Application of Novel Electrical Aging Markers for Irradiated Low Voltage Nuclear Power Plant Power Cables

In this paper, the behavior of low voltage unshielded power cables deployed in nuclear power plants is investigated under radiation stress. The cables were subjected to a 0.5 kGy radiation dose for five different periods. During the whole process, the insulation and jacket were kept intact, and the overall cable degradation was assessed by using dielectric spectroscopy in the frequency range of 100 mHz to 1 kHz. The real and imaginary part of permittivity increased for the whole frequency range with intensity high at low frequencies, representing the intensity of interfacial polarization. Two deducted quantities from the imaginary part of permittivity are introduced, central loss factor and central frequency. The correlation between the two quantities and the absorbed dose was established. With high linear regression values, the quantities showed their potential as an effective electrical aging marker.