“Energy‒environment” life cycle assessment and comparison of a nuclear-based hydrogen production system

Abstract

The use of fossil fuels has caused a global environmental catastrophe. To determine whether low-emission hydrogen to replace fossil fuels can successfully reduce environmental pollution, a comprehensive quantitative analysis of the product's whole industrial chain is necessary. This study proposes evaluating the environmental impacts of a pressurized water reactor (PWR) nuclear-based hydrogen production system using SimaPro and its database based on the life cycle assessment (LCA) method. The system covers fuel (uranium mine) production and use, equipment manufacturing and operation, factory construction and operation, and vehicle production and operation in hydrogen transportation. The emissions of 10 kinds of pollutants in the above four stages are calculated and classified into 6 environmental impact indicators for comprehensive analysis. The results show that the comprehensive energy recovery ratio of existing feasible high-temperature electrolysis (HTE) technology is 17.65%, which is 68% higher than the efficiency of conventional electrolysis (CE) technology. The global warming potential (GWP) of 1 kg H2 produced by PWR-HTE is 2.18 kg CO2 eq, of which the construction, operation, and transportation stages account for 9.6%, 30.7%, and 58.7%, respectively. Except for GWP, the operation stage contributes the highest environmental impact. Energy transition and hydrogen transportation distance are the key parameters with great environmental impacts on the system. Based on the above LCA quantitative research and assessment results, policy development recommendations are proposed for the clean nuclear-hydrogen industry.