This work develops a plate-fueled reactor subchannel steady state heat transfer code (PFSC) using a one-dimensional subchannel model. Verification and Validation is done for the PFSC by deriving several key equations, which are used in the subchannel heat transfer analysis, from the Reynolds Transport Theorem. This activity allows the subchannel model to be extended to include uncertainties and biases associated with the modeling simplifications. The initial basis for the development of the subchannel code is the High Flux Isotope Reactor (HFIR), which is a leading example of a high performance plate-fueled research reactor. The PFSC includes new features from the existing HFIR Steady State Heat Transfer Code (SSHTC). A code to code comparison is done between the new flexible subchannel code and the HFIR SSHTC, as well as a comparison to an analytical solution for a simplified case with uniform heat flux and constant fluid properties. Biases associated with the one-dimensional assessment of the subchannel model are also reviewed. These activities provide quality assurance for the PFSC.