Nanofluid application for heat transfer, safety, and natural circulation enhancement in the NuScale nuclear reactor as a small modular reactor using computational fluid dynamic (CFD) modeling via neutronic and thermal-hydraulics coupling

Abstract

In recent years, “Nanofluid” and “Energy-Efficient Cooling” have been achieved growing attention for use in new nuclear reactor technology. Also, the assurance of reactor safety has become of top priority in nuclear energy development because of the significant role of nuclear power in providing worldwide electricity. The use of nanofluid coolant is an effective way to enhance safety margins and heat transfer performance. Studies also prove that nanofluids are promising cooling fluids for applying as a future coolant in nuclear reactors. The current paper investigates the nanofluid effects as a coolant on the velocity of bulk, pressure drop, heat transfer coefficient, power peaking factors, and minimum departure from nucleate boiling ratio in a NuScale reactor, a natural circulation pressurized water reactor (PWR). It also analyzes the thermal characteristics of Al2O3 nanofluid with specific attention to their boiling heat transfer behavior. The study first presents the NuScale designed core with the use of water and different concentrations of Al2O3 nanofluid (0.001–10% volume fractions and 10–90 nm particle sizes). Then it shows the simulated equivalent cell with surrounding coolant utilizing computational fluid dynamic code (CFD). The study also describes the outcomes of replacing water with nanofluid coolant on natural circulation parameters, heat transfer coefficient, and minimum departure from nucleate boiling ratio with changes in nanoparticle concentrations and sizes. The results demonstrate the potential of this innovative coolant to enhance the minimum departure from nucleate boiling ratio and heat transfer coefficient. Overall, the presence of Alumina nanoparticles in water improves thermal performance and safety. The investigation also shows that the nanoparticles do not change the power peaking factor and neutronic performance significantly.