The features and equations of MixcoatlTM are presented in Part 1 of this two-paper series with no discussion on physics verification. The verification of Mixcoatl specifically for prismatic fuel designs/shell-and-tube–like designs is presented here. Furthermore, conclusions are made on the uncertainties that are extendable to the results of other codes that utilize a one-dimensional (1D) flow assumption with Nusselt correlations. Demonstration of commonly used scenarios for reactor designs is explored, and applicable ranges/deviations from the 1D flow assumption are investigated.