Fig. 1. Diagram of standard fuel assembly (a) and follower fuel assembly (b)

Fig. 2. Core configuration diagram of CARR

Fig. 3. Flow chart in DRAGON for assembly calculation

Fig. 4. Calculation domain (a) and smeared surrounding assemblies (b)

Fig. 5. Diagram of DONJON model of CARR

Fig. 6. Radial relative thermal neutron flux distribution (a) and take the logarithm of y-axis (b)

Fig. 7. Axial relative thermal neutron flux distribution at C3

Fig. 8. Relative deviation of power of each fuel assembly before and after OPTEX optimization

Fig. 9. Axial linear power density distribution of C3 assembly (a) and axial linear power density distribution of B2 assembly (b)