Changes of Electrical Properties of Coaxial Cables Exposed to Gamma-irradiation

Each stress factor initiates different degradation processes. Study of these factors and experiments describing behavior of monitored electrical equipment are important for understanding of stressors synergies. The work is focused on gamma-irradiation as one of the most aggressive degradation factors in nuclear power plants. The aim of this paper is to compare mechanical properties (Elongation at Break - EaB) of dielectric material of a coaxial cable and its electrical properties. Experiments were conducted on two types of coaxial cable with a different kind of dielectric material: Teflon (PTFE) and polyethylene (PE). Monitoring of EaB is commonly used and accepted as a reference method for determination of residual equipment lifetime. However, this destructive testing method is not suitable for the use in power plants. Non-destructive electrical testing is the promising trend in nuclear industry.