Nuclear Technology / Volume 155 / Number 2 / August 2006 / Pages 192-207
Technical Paper / Fuel Cycle and Management
A fuel cycle model - called the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model - has been developed to evaluate well-to-wheels (WTW) energy and emission impacts of motor vehicle technologies fueled with various transportation fuels. The GREET model contains various hydrogen (H2) production pathways for fuel cell vehicle (FCV) applications. In this study, the GREET model was expanded to include four nuclear H2 production pathways: (a) H2 production at refueling stations via electrolysis using light water reactor-generated electricity, (b) H2 production in central plants via thermochemical water cracking using heat from a high-temperature gas-cooled reactor (HTGR), (c) H2 production in central plants via high-temperature electrolysis using HTGR-generated electricity and steam, and (d) H2 production at refueling stations via electrolysis using HTGR-generated electricity. The WTW analyses of these four options include these stages: uranium ore mining and milling, uranium yellowcake transportation, uranium conversion, uranium enrichment, uranium fuel fabrication, uranium fuel transportation, electricity or H2 production in nuclear power plants, H2 transportation, H2 compression, and H2 FCV operation. Our well-to-pump results show that significant reductions in fossil energy use and greenhouse gas (GHG) emissions are achieved by nuclear-based H2 compared to natural gas-based H2 production via steam methane reforming for a unit of H2 delivered at refueling stations. When H2 is applied to FCVs, the WTW results also show large benefits in reducing fossil energy use and GHG emissions.