Nuclear energy presents a compelling pathway for producing hydrogen to decarbonize the steel industry, particularly in direct reduced iron (DRI) processes. Traditional steelmaking relies heavily on coking coal, which acts as both a reducing agent and an energy source in blast furnaces. However, this method generates significant carbon dioxide emissions. Replacing coal with hydrogen derived from nuclear power offers a clean alternative, leveraging the high-temperature steam electrolysis (HTSE) or thermochemical water-splitting processes enabled by nuclear reactors. This shift not only eliminates CO2 emissions from the reduction stage but also aligns with global efforts to achieve net-zero industrial production.

The DRI process typically uses natural gas to produce syngas, a mixture of hydrogen and carbon monoxide, which reduces iron ore to sponge iron. By substituting natural gas with pure hydrogen, the reduction reaction becomes entirely free of carbon emissions. Nuclear-produced hydrogen is particularly advantageous due to its scalability and low-carbon footprint. High-temperature reactors can achieve electrolysis efficiencies exceeding 50%, significantly higher than conventional alkaline or PEM electrolyzers, due to the utilization of waste heat. Thermochemical cycles, such as the sulfur-iodine process, further enhance efficiency by directly splitting water using nuclear heat without electricity.

Integrating nuclear hydrogen into steel plants requires several technical adaptations. First, existing DRI facilities must modify their reformer units to handle pure hydrogen instead of syngas. This involves upgrading gas injection systems, adjusting temperature controls, and ensuring material compatibility with high-purity hydrogen to prevent embrittlement. Second, storage and handling infrastructure must be expanded, as hydrogen demand for DRI is substantial—approximately 50-60 kg of hydrogen per ton of steel produced. Large-scale storage solutions, such as salt caverns or high-pressure systems, become necessary to maintain continuous operations. Finally, safety protocols must be reinforced to address hydrogen’s flammability risks, including advanced leak detection and ventilation systems.

The potential for industrial decarbonization through nuclear hydrogen is substantial. Steel production accounts for nearly 7% of global CO2 emissions, and transitioning to hydrogen-based DRI could eliminate the majority of these emissions. Countries with robust nuclear and steel industries, such as France, Sweden, and Canada, are well-positioned to lead this transition. For instance, Sweden’s HYBRIT initiative, though initially focused on renewable hydrogen, has laid the groundwork for nuclear-hydrogen integration by demonstrating the feasibility of hydrogen-DRI at pilot scale. Similarly, France’s nuclear expertise could enable large-scale hydrogen supply for its steel sector, supported by government policies favoring low-carbon industrial processes.

Partnerships between nuclear and steel industries are beginning to emerge. In the United States, the Department of Energy has explored collaborations between national laboratories and steel manufacturers to assess nuclear hydrogen’s role in decarbonization. Japan’s COURSE50 project, while primarily targeting carbon capture, has also investigated hydrogen injection in blast furnaces, with potential synergies with nuclear-derived hydrogen. These initiatives highlight the growing recognition of nuclear hydrogen as a viable solution for green steel.

Challenges remain, particularly in cost competitiveness and public perception. Nuclear hydrogen production currently faces higher capital costs compared to steam methane reforming, though operational efficiencies and carbon pricing could narrow this gap. Public acceptance of nuclear energy varies, requiring transparent communication about safety and environmental benefits. Despite these hurdles, the combination of nuclear power and hydrogen-based steelmaking represents a technically feasible and scalable route to industrial decarbonization. As trials progress and partnerships deepen, nuclear hydrogen could become a cornerstone of the green steel revolution, offering a clear path toward sustainable heavy industry.

The scalability of nuclear hydrogen production makes it uniquely suited for the steel sector’s enormous energy demands. A single large-scale nuclear reactor coupled with HTSE could produce enough hydrogen to supply a mid-sized steel plant, eliminating millions of tons of CO2 annually. Future advancements in modular reactor designs may further enhance this synergy, enabling localized hydrogen production at steel facilities without extensive grid dependencies.

In summary, nuclear-produced hydrogen holds transformative potential for green steel production. By replacing coking coal in DRI processes, it addresses one of the most carbon-intensive industrial activities while leveraging existing nuclear infrastructure. Technical adaptations, though significant, are surmountable with current engineering knowledge. Early partnerships and pilot projects demonstrate the concept’s viability, paving the way for broader adoption. As the world seeks solutions for deep industrial decarbonization, nuclear hydrogen stands out as a scalable, efficient, and clean alternative for the steel industry.