Study on the application of fiber Bragg grating sensors for the containment structures of nuclear power plants

In this paper, a Fiber Bragg Grating (FBG) sensor system for smart structures is described. FBGs are well-suited for long term and extremely severe experiments, where traditional strain gauges fail. In the system, a reflect wave-length measurement method which employs a tunable light source to find out the center wave-length of FBG sensor is used. The real field test was performed to verify the behaviors of fiber Bragg grating (FBG) sensors attached to the containment structure in Uljin nuclear power plant as a part of structural integrity test which demonstrates that the structural response of the non-prototype primary containment structures within predicted limits plus tolerances when pressurized to 115% of containment design pressure, and that the containment does not sustain any structural damage. The system works very well and it is expected that it can be used for a real-time strain, temperature and vibration detector of smart structure.