Analysis of Eigenvalue Implicit Sensitivity Based on Subgroup Resonance Self-Shielding Technique

The direct effect of the problem-specific multigroup cross sections on the eigenvalue, namely the explicit sensitivity, is obtained efficiently based on the classical perturbation. The expression of resonance self-shielding multigroup cross section sensitivity coefficients with respect to non-resonance nuclide cross sections are deduced based on the generalized perturbation theory for the subgroup resonance self-shielding technique. The indirect effect of non-resonance nuclide on the eigenvalue through resonance self-shielding procedure, namely the implicit sensitivity, can be calculated based on the foresaid two results. The relative importance of the implicit sensitivity is discussed in comparison with the explicit sensitivity.