Enhancing safety in nuclear-powered water electrolysis for low-carbon hydrogen production: A process safety approach

The global transition away from fossil fuels has piqued interest in hydrogen as a low carbon energy carrier. Incorporating meaningful quantities of low-carbon hydrogen into the energy mix requires safe, cost-effective production at scale. This can be realized through utilization of electricity, steam and waste heat from nuclear power plants to power hydrogen production via water electrolysis. Nuclear power plants have critical safety systems to prevent radioactive releases. Concerns arise over the safe operation of pink hydrogen facilities, as usage of highly flammable hydrogen near nuclear facilities may increase fire and explosion risks. This work undertakes a comprehensive identification and review of hazards linked to hydrogen release, separating management strategies by incident prevention and severity limitation. Available data on the size of this fire and explosion risk is limited, and uncertain component failure rates impedes attempts to execute the quantitative risk assessment required for close integration of nuclear and hydrogen systems. However, close integration facilitates usage of nuclear waste heat, increases electrolyzer efficiency, and supports hydrogen production at a cost competitive with that produced using fossil fuels. This paper reviews the relevant works and identifies safe integration of nuclear and hydrogen systems as a key challenge for economical pink hydrogen production and proposes a series of mitigation strategies focused on leak prevention and detection. This supports a better-informed basis of safety for pink hydrogen projects and innovative design recommendations such as those related to spatial configuration.