Nuclear power generation contributes over 50% electricity generation in Ontario and approximately 16% in Canada. Nuclear power is a reliable and clean energy generation technology. Although the amount of GreenHouse Gas (GHG) emissions from the nuclear power generation cycle is not insignificant, it is demonstrated to be much lower than that of fossil fuel energy systems. The GHG level depends on the entire cycle of the nuclear fuel which differs depending on the type of reactor and fuel used. There are several methodologies used in the literature to perform a complete nuclear life cycle assessment (LCA). Significant variations were reported due to the differences in the utilized analysis methods, different contributing phases in the life cycle, as well as the primary energy mix supplying the individual processes. The current study utilizes the process analysis method to perform a life cycle assessment of the Canadian nuclear fuel cycle and the environmental impact based on GHG emissions. The study utilizes the most up-to-date information on the energy mix, and processing methods for each phase of the cycle. This will help establish a fair comparison and to aid policy makers in deciding the future of the energy generating mix in Canada.