Bare fiber Bragg gratings embedded into concrete buffer supercontainer concept for nuclear waste storage

We present the preliminary results obtained with bare fiber Bragg grating-based sensors embedded into half-scale Belgian supercontainer concept. Being temperature and strain sensitive, some sensors were placed into aluminum tubes to monitor only temperature and results were compared with thermocouples data. The utility of using bare fiber Bragg gratings, knowing that these ones are very fragile, is to have a direct contact between the high alkaline environment of the concrete and silica fibers and to determine its impact over a very long time.