[en] Cross sections used in nodal calculations come from infinite medium flux homogenization. Their dependencies from physical working conditions are solved through interpolation on common multi-parameterized tables. If the difference between the neutron spectrum in the true environment and in the infinite medium is relevant, these averaged values do not permit to represent true reaction rates. For example, the error induced is not negligible with neighboring assemblies with different compositions. This is the case of UO₂ assemblies placed near MOX assemblies. The purpose of the method presented here is determining a homogenization correction to multi-group cross sections, corresponding to the difference between the environmental and infinite medium spectrum. An investigation of the feasibility of using the spectral re-homogenization as method to model the dependence of the cross sections on local conditions, such as the insertion of a control rod bank, is presented. (authors)