Measures of the environmental footprint of the front end of the nuclear fuel cycle

Previous estimates of environmental impacts associated with the front end of the nuclear fuel cycle (FEFC) have focused primarily on energy consumption and CO2 emissions. Results have varied widely. This work builds upon reports from operating facilities and other primary data sources to build a database of front end environmental impacts. This work also addresses land transformation and water withdrawals associated with the processes of the FEFC. These processes include uranium extraction, conversion, enrichment, fuel fabrication, depleted uranium disposition, and transportation.To allow summing the impacts across processes, all impacts were normalized per tonne of natural uranium mined as well as per MWh(e) of electricity produced, a more conventional unit for measuring environmental impacts that facilitates comparison with other studies. This conversion was based on mass balances and process efficiencies associated with the current once-through LWR fuel cycle.Total energy input is calculated at 8.7 × 10− 3 GJ(e)/MWh(e) of electricity and 5.9 × 10− 3 GJ(t)/MWh(e) of thermal energy. It is dominated by the energy required for uranium extraction, conversion to fluoride compound for subsequent enrichment, and enrichment. An estimate of the carbon footprint is made from the direct energy consumption at 1.7 kg CO2/MWh(e). Water use is likewise dominated by requirements of uranium extraction, totaling 154 L/MWh(e). Land use is calculated at 8 × 10− 3 m2/MWh(e), over 90% of which is due to uranium extraction. Quantified impacts are limited to those resulting from activities performed within the FEFC process facilities (i.e. within the plant gates). Energy embodied in material inputs such as process chemicals and fuel cladding is identified but not explicitly quantified in this study. Inclusion of indirect energy associated with embodied energy as well as construction and decommissioning of facilities could increase the FEFC energy intensity estimate by a factor of up to 2.

► Operational data and environmental impact documentation from contemporary facilities was used to inform a new estimate of the environmental footprint of nuclear fuel cycle technologies. ► The CO2 footprint of technologies comprising the front end is found to be 1.7 kg CO2 per MWh(e) of nuclear electricity generated by a typical present-day reactor. ► The new data shows that the front end nuclear processes are somewhat more water intensive than their equivalents in the coal and natural gas fuel cycles, but around an order of magnitude less land intensive.