Westinghouse Electric Company (WEC) and the Savannah River National Laboratory (SRNL) have independently developed different process flowsheets for the hybrid sulfur process for hydrogen generation using an advanced nuclear reactor heat source (such as the pebble-bed modular reactor, or PBMR). The two efforts have differed in design philosophy, the process simulators used to develop the heat and material balances (CHEMCAD™ and Aspen Plus™, respectively), and to a lesser extent the basic thermodynamic data underlying the simulations. A collaboration is now underway between the two groups to simplify and optimize the two designs, and to consolidate them into a single reference flowsheet. The revised flowsheet attempts to optimize unit operation cost, fabricability, and maintainability (e.g. minimizing pressure drops in very high temperature components); provide the electrolysis units with a uniform sulfuric acid feed concentration (to optimize electrolyzer performance and minimize development requirements); match assumed electrolysis conversion efficiency with the most recent experimental data from SRNL; rationalize differences in thermochemical data; minimize the total number of unit operations (for cost optimization); and maximize SO2 recovery following sulfuric acid decomposition by modifying system operating pressures.