Fig. 1. 1/6 upper plenum chamber structural model and 1/6 core outlet channel distribution (a) Main view, (b) Core outlet channel

Fig. 2. Temperature point monitoring arrangement in the upper plenum chamber (color online)

Fig. 3. Computational grid of 1/6 upper plenum chamber structure

Fig. 4. The variation of liquid sodium's temperature and mass flow rate at the core typical outlet with time (color online)(a) Temperature, (b) Mass flow rate

Fig. 5. The deviation between the simulated and experimental results of liquid sodium temperature at four different vertical heights (color online)

Fig. 6. The variation of temperature and velocity at the core typical outlet with time (color online) (a) Temperature, (b) Velocity

Fig. 7. Temperature and velocity distribution of LBE at vertical and horizontal planes (color online) (a) Temperature, (b) Velocity

Fig. 8. Temperature distribution of LBE in the upper plenum chamber at different times (color online)(a) 60 s, (b) 120 s, (c) 180 s, (d) 240 s, (e) 300 s, (f) 400 s

Fig. 9. Velocity and streamlines at different times (color online) (a) 120 s, (b) 240 s

Fig. 10. Velocity vector at small holes (t=240 s, color online) (a) Lower inner hole, (b) Upper inner hole

Fig. 11. Transient temperature distribution of LBE in the vertical direction (color online) (a) 120~240 s, (b) 300~600 s

Fig. 12. Temperature variation of LBE at different heights (color online) (a) Lower region of the small hole, (b) Upper region of the small hole

Fig. 13. Position variation of thermal stratification interface