Nuclear Steel: Process Design and Techno-Economic Analysis of High-Temperature Gas-Cooled Reactors with Steam Electrolysis for DRI–EAF Steelmaking

Abstract

This study presents an integrated process design for a nuclear-steelmaking system consisting of a high temperature gas cooled reactor (HTGR), steam turbine and cycle equipment, solid oxide electrolysis cell (SOEC) hydrogen production system, and direct reduced iron (DRI) – electric arc furnace (EAF) steelmaking system. The process aims to leverage the efficiency of HTGR power conversion along with the low electricity intensity of steam electrolysis to generate cost-competitive low-carbon-intensity steel. The process design is represented through a flowsheet model of the mass and heat integrated system in Aspen Plus. Key performance parameters and efficiencies are derived from the thermodynamic model and benchmarked against values reported by published literature and commercial vendors. Furthermore, the system cost analysis derives a $2.90/kg H2 figure for all costs excluding the HTGR capital and O&M costs. Given the wide uncertainty in HTGR cost estimates, a target HTGR capital cost is instead derived for a range of levelized hydrogen production costs. For the HTGR capital cost range of 1700 - 3000 $/kWth suggested by literature, the levelized cost of steel ranges from 860 - 1080 $/ts, which represents a low-carbon steel premium of roughly 300 - 500 $/ts over prevailing steel prices today. While navigating the challenge of cost uncertainty, this study aims to present an integrated HTGR-SOEC-Steelmaking system design not previously reported in the literature and lays the groundwork for future work in technical refinement, heat exchange loop optimization, sensitivity analyses, and robust cost-competitiveness analysis that will evolve as additional data from research and commercial deployments become available.