MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a flexible fast-spectrum research reactor under design at SCK•CEN, the Belgian Nuclear Research Centre. MYRRHA is a pool-type reactor with Lead Bismuth Eutectic (LBE) as the primary coolant. For the safety evaluation and licensing of MYRRHA the temperature of the primary coolant in the reactor vessel and the fuel assemblies in the core must be assessed for different scenarios, which is performed with a combination of both simulations and scaled experiments for proof-of-principle and validation purposes.
In previous thermal-hydraulic and chemistry tests performed at SCK•CEN in LBE at representative conditions, temperature measurement was based mainly on thermocouples, which provide information at rather low spatial resolution. On the other hand, fiber sensors based on optical measurement techniques can provide detailed information at high spatial resolution, which can be a game changer for the validation of simulation tools. At SCK•CEN, discrete fiber sensors have been used in LBE for measuring flow-induced vibrations. Elsewhere, distributed fiber sensors have been used for measuring temperature but not in LBE. The next logical step is to combine these experiences.
The primary objective of this Post-Doc study is to investigate the applicability of fiber sensors for distributed temperature measurements in LBE. Particular focus shall be placed on developing a calibration procedure, as well as practical guidelines for handling and mounting of delicate fibers. Moreover, fiber sensors shall be installed in experimental setups under construction or commissioning for thermal-hydraulic and/or chemistry tests.