“…[4,14,15] The recombination process directly depends on the energy distribution of electrons, which, in its own turn, depends on the evolution of the energy spectra of fission fragments created precisely by the neutron flux distribution in the active zone of a nuclear reactor. [6,30] Taking into account fast, slow and very slow time scales, the time-dependent energy distribution functions for fission fragments and electrons might be obtained from (Equation (1),Equation ( 13)): ) .…”