Applicability test of the raman distributed temperature sensor for FBR plant instrumentation

Sumino, Kozo ; Ichige, Satoshi ; Fukami, Akihiro*; Maeda, Yukimoto; Suzuki, Soju

The Raman Distributed Temperature Sensor (RDTS) based on the Raman Scattering Phenomena in the optical fiber is a system, which can easily measure the accurate temperature distribution. In order to evaluate the applicability of RDTS for FBR plant instrumentation, a temperature distribution measurement using RDTS was performed in the primary cooling system of JOYO. By using two optical fiber sensors, which were installed spirally around the primary piping, the temperature distribution on the primary piping was measured from the 30th through the 32nd duty cycle. In addition, the same test was carried out in the secondary cooling system of JOYO in order to test the measurement data from the primary cooling system. The main results were as follows; (1) The temperature data in the primary cooling system was acquired over 180EFPDs of operation at JOYO (accumulated dose : 3 10 R). (2) The chracteristics of FTR in the high dose rate nuclear plant environment was confirmed. (3) The radiation induced temperature errors were calibrated succesfully by using thermocouple readings. The accuracy of the temperature after calibration was approximately 3C. (4) It was confirmed that diffent fiber and insulator settings on the piping cause temperature changes.