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The application of distributed optical fiber sensing technology in nuclear island safety monitoring is mainly studied in this paper. The anti-radiation ability of the system is an important index. The distributed optical fiber system in this paper is designed with a special anti-radiation optical fiber. The temperature of power supply cables and other facilities in the nuclear island containment can be distributed monitored in full period in real time. Radiation tests are carried out to validate the anti-radiation performance of the system. 60Co is used as a gamma ray radiation source to generate continuous pulses with an average energy of 1.25 MeV. The rate of radiation dose is 1800 Gy/h and the total radiation dose is 1950 Gy. The anti-radiation ability of anti-radiation optical fiber and common optical fiber is compared. It is proved by tests that common optical fiber sensor has great fiber loss in radiation environment, about 0.5dBm, and the loss is decreasing continuously. Anti-radiation optical fiber has little fiber loss in radiation environment, about 0.12 dBm, and the loss tends to be saturated. During the radiation test, the temperature measurement performance of the distributed optical fiber sensing system using anti-radiation optical fiber and the one using common optical fiber is tested in real time. The results show that the anti-radiation distributed optical fiber sensing system performs well in the whole process, which meets the requirements of temperature monitoring for 1339.2 Gy total radiation dose in the refueling cycle of nuclear island.
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