Fig. 1. Schematic diagram of solid core structure and calculation unit selection

Fig. 2. Coupled irradiation-thermal-mechanical model of solid core

Fig. 3. Boundary condition and numbering setting for coupled irradiation-thermal-mechanical model (a) Boundary condition, (b) Heat pipe and fuel numbering scheme

Fig. 4. Steady-state temperature distribution contour of solid core fuel

Fig. 5. Steady-state stress distribution contour of solid core fuel

Fig. 6. Minimum gap between pellet and cladding (a), between monolith and cladding (b), between monolith and HP (c) varying with running time

Fig. 7. Variation of maximum temperature of pellet with running time

Fig. 8. Creep of monolith and cladding at operation period of 2 000 d (a) Monolith, (b) Monolith and cladding

Fig. 9. Variation of strain on the outer wall of cladding #7