Understanding flow behaviour in molten salts is critical to the development and safe operation of next-generation nuclear reactors, including fusion and molten-salt fission systems. These fluids play essential roles in heat transfer, coolant circulation, and tritium breeding, yet their extreme temperatures and corrosive chemistry make conventional measurement techniques challenging and often impractical. This PhD project will develop a novel, high-resolution diagnostic tool based on the Wire Mesh Sensor (WMS) to measure phase fraction distribution and temperature distribution in reactor-relevant molten salt environments. Originally designed for light-water systems, the WMS concept must be fundamentally reimagined to operate under the highly conductive, high-temperature conditions typical of advanced nuclear systems. Working across two state-of-the-art facilities, the molten salt loop at the University of Leeds and the SMALLAT testbed at UKAEA, the successful candidate will gain experience in sensor development, experimental fluid mechanics, and high-temperature instrumentation while generating benchmark data to validate advanced computational models used in reactor design and safety assessment.
The project directly supports the UK’s ambitions in both fusion and advanced fission by addressing a key knowledge gap that underpins the safe and efficient deployment of next-generation reactors. Molten salts feature prominently in reactor concepts of strategic importance to the UK, particularly within UKAEA fusion programmes and emerging molten-salt fission designs. By establishing a diagnostic capability that does not currently exist for these challenging conditions, the project will strengthen the scientific evidence base required for reactor licensing, materials and component design, and system performance prediction. Its outputs will contribute to national priorities in clean energy, energy security, and technological leadership, benefiting UKAEA and the wider nuclear sector as the UK advances toward a low-carbon future.