This work presents an accurate model for the description of the radiative transfer processes that take place in reacting porous media subjected to high temperatures. In it, we solve the transport equation for radiation leveraging a low order spherical harmonic expansion, P1, to describe the angular dependence of the radiative intensity. This radiation model is tightly coupled with CHyPS, a material response solver developed within the CHESS that can simulate the heat and mass transfer in porous materials. CHyPS solves volume-averaged governing conservation equations for solid mass, gas mass, species (finite-rate chemistry), momentum, and energy. Model predictions are compared against several test cases published in literature demonstrating excellent agreement in the predictions. Finally, we present a demonstrative simulation of the heat shield used for the Dragonfly mission’s entry capsule.