GE Hitachi Nuclear Energy proposes the use of the pyroprocessing techniques to effectively close the nuclear fuel cycle. In order to better understand the quantities of inputs and their effect on the outputs (waste packages, product, etc.) of the process, an integrated process model was designed to track mass flows and aid in sizing and quantifying the amount of equipment needed for different desired throughputs. The flowchart that was modeled is discussed, and each process is explained in detail from the front-end fuel preparation through waste generation and product accumulation. The chemical, electrochemical, and mechanical operations of these processes are also identified and explained. Process parameters that the model allows the user to vary are also identified, and the effects of changing these parameters are also discussed.