Optical fiber sensors to improve the safety of nuclear power plants

Abstract

Safety must always prevail in Nuclear Power Plants (NPPs), as shown at Fukushima-Daiichi, in March 2011. So, innovations are clearly needed to strengthen instrumentations, which went inoperative during this nuclear accident as a consequence of power supply losses. Possible improvements concern materials and structures, which may be remotely monitored thanks to Optical Fiber Sensors (OFS). We detail topics involving OFS helpful for monitoring, in nominal conditions as well as during a severe accident. They include distributed sensing (Rayleigh, Raman, Brillouin) for both temperature and structure monitoring as well as H 2 concentration and ionizing radiation monitoring. For future plants, Fiber Bragg Grating (FBG) sensors are considered up to high temperature for sodium-cooled fast reactor monitoring. These applications can benefit from fiber advantages: sensor multiplexing, multi-km range, no risk-to-people, no common failure mode with other technologies, remote sensing, and the ability to operate in case of power supply loss in the NPP.

Gd3+-doped sol-gel silica glass for remote ionizing radiation dosimetry

“…Such dosimeters should ideally present the remote measurement ability, in real-time and/or with a high spatial resolution. This concerns the field of new techniques for radiotherapy, as well as in space and nuclear domains [5][6][7][8][9]. For these applications, fibered solutions seem particularly adapted and new sensitive materials, such as rare-earth (RE) doped glasses, can be drawn into fibers.…”

Temperature Resistant Fiber Bragg Gratings for On-Line and Structural Health Monitoring of the Next-Generation of Nuclear Reactors

“…Several innovative solutions have been considered in order to provide tools for on-line monitoring of fast reactor nuclear cores. These are not limited to acoustic and ultrasonic sensors, inspection robots, fission chambers, laser-based spectroscopy techniques for pile gas composition analysis, radiation-hardened thermocouples [ 6 ] but also encompass optical fiber sensors [ 7 , 8 , 9 , 10 ]. Sensors probing the nuclear core from outside the pool are ideal (ultrasonic sensors) but not always possible.…”

Component- and system-level degradation modeling of digital Instrumentation and Control systems based on a Multi-State Physics Modeling Approach

“…2, below. Uchanin and Najda, 2011) and optical fiber sensors (Ferdinand et al, 2013). Without loss of generality, we assume that the S-A and S-B of the digital I&C system of Fig.…”