Criticality calculations in a nuclear reactor by using the Lyapunov exponent method

Highlights: ► Coupled map lattice theory is applied to the multi-group diffusion equations. ► Mean Lyapunov exponent theory is applied in stability analysis. ► Stability of the slab reactor with respect to the enrichment is studied. ► By using the MCNP and ANSIN codes the obtained results are controlled. - Abstract: This paper studies the stability of the slab reactor with respect to the enrichment. For this purpose, the coupled map lattice theory is applied to the multi-group diffusion equations. Applying mean Lyapunov exponent theory introduced by Shibata [H. Shibata, Physica A 264 (1999) 226] on the model shows that, two successive phases: subcritical and supercritical. In order to compare the performance of the selected method by using the MCNP and ANISN codes the obtained results controlled. The model, in spite of its simplicity in form, shows a greater efficiency in prediction of critical enrichment.