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 design and safety evaluation of MYRRHA the temperature of the primary coolant must be assessed for different scenarios. This is performed with a combination of simulations and scaled experiments for proof-of-principle and validation purposes.
Current techniques for the measurement of temperatures and velocities in opaque fluids like LBE allow to acquire data with good accuracy but with a limited spatial and/or temporal resolution. The measurement of velocity and temperature fluctuations, quantifying the momentum and thermal variations in time, remains a challenge. The simultaneous measurement in space and time of both fluctuations provides unique information on the turbulent heat flux and will quantify the turbulent thermal diffusivity, which is a fundamental term in the modelling of turbulent heat transfer in liquid metals. The PhD thesis aims at developing high-fidelity instruments to acquire these two fluctuating quantities in liquid metals.