Several efforts have been spent in recent years to address the simulation challenges posed by the non-conventional design of Molten Salt Reactors (MSRs). One of the design specificities of MSRs is the volume heat source in the liquid fuel, which has been proven by various authors to significantly alter the heat transfer processes in these reactors. This paper focuses on the impact of a volume heat source on the wall treatment of the standard high-Reynolds Reynolds-Averaged Navier Stokes (RANS) turbulence models. A modified thermal wall function is derived and its impact is discussed for typical MSR calculations. The results show a non-negligible impact on graphite temperatures, both at steady state and during transients. (C) 2019 Elsevier Ltd. All rights reserved.