Abstract
This paper describes the fundamental characteristics of the residual voltage and the relationship between irradiation dose and residual voltage in electric power cable using in nuclear power generating station. The residual voltage of unirradiated cable increases with time, tending to saturate. The saturated value of residual voltage is nearly proportional to bias voltage. This result supports that the residual voltage of cable is caused by depolarization. From theoretical and experimental investigation we found that the residual voltage is not influenced by cable size and length. This is important merit of residual voltage as the nondestructive diagnosis. When dose is more than 500kGy, the residual voltages exhibit a peak. As the irradiation dose is increased, the peak moves to the shorter time. Therefore, we can know the degree of radiation degradation from the location of the peak.
