Detection and Localization of the Hot Spot in Nuclear Control/Instrumentation Cable Using Time- Frequency Domain Reflectometry

Time-frequency domain reflectometry method using Gaussian enveloped linear chirp signal is used to detect and to locate the hot spot in nuclear control and instrumentation cable. The reference signal designed to fit for the characteristic of target cable is applied to target cable including hot spot which is simulated in heating chamber. Using the Wigner distribution, the reflected signal from the hot spot is analyzed in time-frequency domain. To estimate the hot spot location, the time-frequency cross correlation is applied to control and instrumentation cable. The experiment, considering insulation properties in thermal environment, are performed on three types of cables depending on insulation (EPR, HFI, FTFE). To detect the hot spot in target cable, the additional experiment which is…