Radiation transfer is relevant to a number of key technical issues related to nuclear reactor safety studies. To gain understanding of thermal radiation transfer under hypothetical reactor accident conditions, analysis of radiation transfer in a finite length cylindrical vessel containing high-temperature aerosols that absorb, emit, and scatter thermal radiation has been performed. The fine particles are assumed to be produced by the dispersion of the reactor core debris under high pressure. The model parameters used in the calculations correspond to those proposed in the High-Pressure Melt Streaming experimental program. Results of calculations show that the extinction coefficient and the single scattering albedo of the aerosol and the emissivity of the vessel are important model parameters. The sensitivity studies have identified the radiative property data base needed to make realistic radiative transfer calculations relevant to hypothetical reactor accidents in which fine aerosol particles are generated from the core debris.