Lifetimes of Cable Insulations Subjected to Thermal and Radiation Stresses

This paper presents a method for calculating the estimated, consumed, and remaining lifetimes of power cable insulation subjected to thermal and radiation stresses. New calculation relationships are proposed for lifetimes under both constant and time-varying stresses. The results show that consumed lifetime values increase, while estimated and remaining lifetimes decrease with increasing temperature and dose rate, and that these variations are more pronounced in the case of variable stresses exceeding the nominal operating limits of the insulation. Finally, it is shown that calculating the remaining lifetime values enables more effective monitoring and the implementation of a comprehensive maintenance program for power cables.