Both radiation-induced excess vacancies and solute-interstitials may enhance solute diffusion. The radiation-enhanced solute diffusion promotes the kinetic process of equilibrium segregation. This effect is especially considerable in the low temperature range. As a complement to modelling of radiation-induced non-equilibrium segregation, the radiation-created vacancy and solute-interstitial-accelerated equilibrium grain boundary solute segregation were theoretically treated. The models were applied to phosphorus segregation in α-Fe subjected to neutron irradiation. Both radiation-induced excess vacancies and solute-interstitials may enhance solute diffusion. The radiation-enhanced solute diffusion promotes the kinetic process of equilibrium segregation. This effect is especially considerable in the low temperature range. As a complement to modeling of radiation-induced non- -equilibrium segregation, the radiation-created vacancy and solute-interstitial-accelerated equilibrium grain boundary solute segregation were theoretically treated. The models were applied to phosphorus segregation in α-Fe subjected to neutron irradiation.