Nuclear power driven high temperature steam electrolysis for hydrogen production: a systematically synergistic optimization driven high temperature steam electrolysis for hydrogen production: a systematically synergistic optimization

Hybrid nuclear-hydrogen energy system provides a promising pathway for deep decarbonization. However, flexible load-following operation of nuclear power for peak shaving can reduce its power generation efficiency and place high demand on synergistic characteristic of systematic power distribution and thermal energy utilization. To address this issue, the current work proposes a synergistic optimization strategy for nuclear power driven high temperature steam electrolysis system. At the systematic level, a linearized power distribution model is developed to optimize reactor load-following and hydrogen production. Meanwhile, a detailed thermodynamic model of high temperature steam electrolysis system is also established, and pinch analysis is applied to optimize its internal heat exchanger network and analyze the heat-load matching characteristics within the system. The optimized hybrid nuclear-hydrogen system reduces total net cost by 10.2% while enabling hydrogen production capacity of 417 t/d. When the operating temperature of solid oxide electrolyzer is increased from 700 °C to 850 °C, hydrogen production efficiency raises from 68.65% to 72.85% because of enhanced electrochemical kinetics and reduced ohmic losses. In contrast, the external superheated steam temperature exhibits a threshold effect. When it exceeds the appropriate range, the minimum system cooling demand increases sharply from 1152 kW to 1857 kW, leading to a decrement in overall system efficiency from 71.38% to 68.02%. The current work demonstrates that synergistic optimization of reactor load-following operation for peak shaving and high temperature steam electrolysis can effectively improve the flexibility, energy utilization efficiency, and economic performance of hybrid nuclear-hydrogen energy system.