Study on the thermo-hydraulic behaviors within a CiADS 61-pin wire-wrapped fuel assembly under porous blockage conditions based on LBEblockageFoam

• Published in: Annals of nuclear energy 2024-12, Vol.208, p.110734, Article 110734
• Main Authors: Li, Yun-Xiang, Yang, Run-Sheng, Li, Yue, Su, Xing-Kang, Han, Yi-Wen, Huang, Zi-Nan, Meng, Lu, Li, Song, Zhang, You-Peng, Zhang, Lu, Jiang, Wei
• Format: Article
• Language: English
• Subjects: CFD simulations; CiADS; OpenFOAM; Porous blockage; Spacer wires
• ISSN: 0306-4549; 1873-2100
• DOI: 10.1016/j.anucene.2024.110734

•The LBEblockageFoam solver is validated as highly precise and apt for the flow and heat transfer assessments in coolant within porous media blockage conditions.•Porous blockages induce downstream recirculation zones, which will diminish its cooling capacity and cause localized heat transfer deterioration.•An increase in the blockage area and thickness may significantly elevate local hotspot temperatures, which may cause cladding failure.•Porous blockages located in the middle of the fuel assembly are reported to cause a more pronounced effect than those at the ends.•As porosity increases, the high-temperature area tends to move further downstream, indicating a nonlinear relationship between porosity changes and downstream coolant heat transfer efficiency. In lead-based fast reactor fuel assemblies, coolant-induced corrosion may lead to the precipitation and the accumulation of corrosion products that may cause blockage in flow channels. Such blockages in porous medium may affect the coolant’s flow and heat transfer characteristics. Therefore, the thermal performance of fuel rod claddings and reactor’s safe performance may also be affected. To assess the effects of porous medium blockage on flow and heat transfer within lead-based reactor fuel assemblies, the LBEblockageFoam solver was developed on the open-source CFD platform OpenFOAM. This study evaluates the impact from blockage parameters, including area, axial length, axial position, and porosity, on flow field distribution and heat transfer deterioration under different blockage scenarios. The results reveal that blockages induce downstream recirculation zones, which will diminish its cooling capacity and cause localized heat transfer deterioration. An increase in the blockage area and axial length may significantly elevate local hotspot temperatures, which may cause cladding failure. Blockages located in the middle of the fuel assembly were reported to cause a more pronounced effect than those at the ends. Additionally, as porosity increases, the high-temperature area tends to further downstream, indicating a nonlinear relationship between porosity changes and downstream coolant heat transfer efficiency.