Integration of Hydrogen Production Using High Temperature Steam Electrolysis with Advanced Nuclear Energy Systems

With the promise of increased economics and improved safety, advanced nuclear reactors, such as the Natrium design by TerraPower and GE Hitachi, can help many electricity energy markets transition to carbon-free power smoothly. Operating at higher temperatures, the Natrium design based on a sodium fast reactor is suitable for co-located hydrogen production using high temperature steam electrolysis. This study models and analyzes three Natrium integrated energy systems with thermal energy storage and co-located hydrogen production. The first two configurations focus on improving thermal efficiency of the reheat Rankine cycle used in the Natrium design, while the final configuration improves hydrogen production efficiency. Results indicate that coupling the Natrium system with hydrogen production can boost its energy efficiency by 1%, and using low grade steam directly from the Natrium steam cycle for hydrogen production significantly reduces system complexity and increases the overall system efficiency by 3%. • Three nuclear-hydrogen integrated systems configurations are dynamically modeled. • Three efficiency metrics are defined and to compare the integration configurations. • Efficiency gains occur in all configurations, varying with power and hydrogen output. • Using low-grade steam for hydrogen improves efficiency and reduces system complexity.