Distributed Fibre Optic Temperature Measurement System For The Safety Monitoring Of The Next Generation Of Large Nuclear Facilities

The range of applications of optical fibre distributed temperature sensors is rapidly expanding in the industry. Nowadays, this fibre optic sensing technology is mature for industrial applications such as fire detection inside buildings and tunnels, process vessel monitoring, leak detection in cryogenic storage vessels (liquid natural gas, ammonia, and ethylene) or oil wells and the measurement of energy cable thermal distribution for the power supply industry. Nuclear industry shows a growing interest for the possibilities offered for fibre optic temperature sensing applications. Fibre optic sensing technology could be considered as an alternative to classical measurements techniques in a wide range of applications. The potential of distributed temperature measurements for the monitoring of large nuclear infrastructures such as reactor containment buildings, nuclear waste repositories and reactor primary circuitry have already been shown. In this paper, we evaluate the double-ended Raman detection scheme up to more than 300 kGy. We show that this industrial detection unit can cope with radiation-induced losses, without any specific calibration technique.