Heat removal and hybrid ventilation characteristics of a vertical dry storage cask for spent nuclear fuel

Highlights: • Avertical dry storage cask for spent nuclear fuelis our target. • Heat removal and hybrid ventilation characteristicswerenumericallyinvestigated. • Buoyant airflow dominated heat removal at low Re (2.7 × 10⁴). • When Re = 5.3 × 10⁴–1.3 × 10⁵, wind-induced airflow compromised the buoyant one. • When Re ≥2.7 × 10⁵, wind-induced airflow dominated and heat removal increased. Computational fluid dynamics (CFD) was used in this study to numerically simulate the heat removal and hybrid ventilation characteristics of a vertical dry storage cask for spent nuclear fuel. The parameters included a Grashof number of 1.0x10¹¹, an approaching wind incidence angle of 0° or 45°, and a Reynolds number (Re) of $\text{2.7}\times {10}^4-\text{8.0}\times {10}^5$ ($\mathrm{Gr}/{Re}^2\text{=}0.15-1\text{37}$). As shown by the results, the buoyant airflow dominated the heat removal capability of the cask at low Re ($\text{2.7}\times {10}^4$). When the Re was increased to $\text{5.3}\times {10}^4-\text{1.3}\times {10}^5$, the wind-induced channel airflow compromised the buoyant airflow, thus reducing the heat removal capacity of the cask. When the Re was$⩾\text{2.7}\times {10}^5$, the wind-induced airflow dominated.