Fixed-bed reactors often operate at elevated temperatures, where radiation can be a significant heat-transfer mechanism. Particle-resolved CFD models fixed-bed reactors on a very detailed macroscopic level. In this study, the contribution of radiative heat transfer is investigated in a 500-mm bed of 7-hole pellets. At industrially relevant temperatures (250 - 800 degrees C) and with a steam-reforming gas-phase mixture, the S2S and DOM radiation models were applied. Neglecting radiation results in temperatures being up to 6 % lower. In this case, the main driver is surface-to-surface (S2S) radiation. Additional modeling recommendations are given.