Fig. 1. Core Layout of EBR-II 138B (color online)

Fig. 2. Radial distribution of burnup in the active zone

Fig. 3. Geometry of the fuel element (color online)

Fig. 4. Axial geometry of typical assemblies (color online) (a) Axial structure of driver assembly, (b) Axial structure of high-worth control assembly

Fig. 5. Radial geometry of typical assemblies (color online)

Fig. 6. Super-assembly model of poison rods in high worth control assembly (color online)

Fig. 7. Spatial distribution of the nuclide densities of U-235 (color online)

Fig. 8. Model factor distribution in the core (color online)