Fig. 1. Structural diagram of the solid hexagonal prism graphite component (a) and control rod channel component (b)

Fig. 2. Schematic diagram of computational model for assembly core structure

Fig. 3. Structural diagram of the support plate

Fig. 4. Variations of neutron escape, capture, and fission due to geometric displacement caused by thermal expansion with temperature in the range of 550⁓700 ℃

Fig. 5. Variation of k_eff due to changes of thermal expansion density with temperature in the range of 550⁓700 ℃

Fig. 6. Variations of neutron escape, capture, and fission due to density changes with temperature in the range of 550⁓700 ℃

Fig. 7. Distribution of reactivity changes with the displacement of graphite assembly in the random model (color online)

Fig. 8. Distribution of reactivity changes with the displacement of graphite assembly in the extreme model

Fig. 9. Variations of neutron escape and absorption with the displacement of graphite assembly in the extreme model

Fig. 10. Linear fitting result between the average displacement ΔR and the reactivity difference Δρ

Fig. 11. Variation of graphite irradiation-induced deformation rate with neutron fluence and temperature^[5]

Fig. 12. Top (a) and side (b) views of fast neutron flux distribution

Fig. 13. Radiation-induced deformation of different blocks in the graphite assembly at the 4th year (a), 8th year (b), 12th year (c), and 16th year (d)

Fig. 14. Percentage change of core fuel loading due to graphite irradiation-induced deformation at different times

Fig. 15. Reactivity changes caused by graphite irradiation swelling

Fig. 16. Neutron capture and fission weight of the second (a) and sixth (b) blocks of each graphite assembly circle at different irradiation times