This paper contains the results of a numerical investigation of the effects of internal radiation on heat transfer during cyclic heating and cooling of a phase-change energy-storage system. The effects of internal radiation, temperature distribution and energy stored and extracted were investigated. An absorbing, emitting, and isotropically scattering, finite, and semi-transparent, gray, phase-change medium bounded between two concentric cylinders was studied. The phase-change medium was a fluoride salt with LiF (41.27%), MgF, (48.76%) and KF (8.95% by weight). Radiative heat transfer affects the dynamics of phase changes significantly for low values of th conduction-radiation interaction parameter.