Numerical investigation for the spent fuel storage building design of the Chinshan nuclear plant

Highlights: • All the spent fuels of the Chinshan plant will be stored in the dry casks located a spent fuel storage building. • Decay heat generated by the spent fuel is removed by the natural convection of the air. • Single-cask and storage-building model are coupled analysis in this study. • Analysis models are developed using Computational Fluid Dynamic. A spent fuel storage building is planned to be built in the Chinshan plant in Taiwan. All the spent fuel of the Chinshan plant will be stored in the dry casks located in this building. In this paper, thermal analyses of the casks and the storage building are performed using Computational Fluid Dynamics (CFD). For safety requirement, no forced-convection device is considered in this study. Decay heat generated by the spent fuel is removed by the natural convection of the air. First, a single-cask model is developed to provide the flowrate and temperature rise of the induced air flow. Then, another model is developed to calculate the flow and temperature distributions of the storage building. The induced airflow of the casks is either treated with the information obtained from the single-cask model, or calculated by assuming that the casks as simple cylinders with volumetric heat sources. Assuming that the heat load of each cask is 20 kW, the results show the average air temperature around the ground would not hurt the staff while working in the storage building. It is also found that the gross results of the building space predicted by two different ways treating the casks are consistent. Thus, simply treating the casks as cylinders with volumetric heat sources can be applied to further analysis with less computational cost. A sensitivity study about the building model is also performed as references for the future designs of the cask storage building of the Chinshan plant.