Fig. 1. The schematic diagram of the optimized core of LFR^[56]

Fig. 2. Fuel assembly load scheme^[57]

Fig. 3. The cladding temperature at the FPS outlet (a) and temperature stratification in LBE pool (b)^[67] (color online)

Fig. 4. Distribution of fuel particle concentration in the coolant during the tramsigent process^[69] (color online)(a) 10 s, (b) 60 s, (c) 100 s, (d) 200 s, (e) 500 s, (f) 1 000 s

Fig. 5. Response of the LFR core power control system after the introduction of 20 pcm reactivity^[71] (color online)

Fig. 6. Oxygen concentration control in the LBE circulation loop (a) and testing of oxygen sensors at different temperature (b)^[11] (color online)

Fig. 7. Variations of Po average concentration in the covering gas and the containment with evaporation interface temperature^[80]