The Clogging Mechanism of Nanofluids in the Cooling System of Nuclear Reactors

Nanofluids have the potential to enhance heat transfer efficiency and increase safety margins in nuclear reactor cooling systems due to their superior thermophysical properties, such as significantly improving the thermal conductivity of the base liquid and enhancing convective heat transfer and critical heat flux. However, the deposition of nanoparticles within the system causes complex clogging problems, resulting in reduced flow channel cross-sectional area, increased pressure drop, deteriorated heat transfer and equipment wear. The blockage is caused by the combined effects of nanoparticle characteristics, fluid dynamics conditions and environmental or material factors (e.g., temperature, pressure, wall roughness). The clogging behavior of nanofluids in special conditions (such as strong corrosiveness and radiation fields) for advanced reactors (lead-cooled fast reactors, sodium-cooled fast reactors, molten salt reactors, and supercritical water-cooled reactors) has not been fully elucidated. Future work should focus on surface-modified particles, multi-scale simulations/machine learning for deposition prediction, and long-term behavior in extreme conditions. Controlling blockages is critical for scaling nanofluids in nuclear energy.