The economic viability of a power plant is dependent on the cost of the electricity generated which is influenced by a wide range of factors and inputs from the inception to end of economic life. The Levelized cost of energy or electricity (LCOE) is a model used to estimate the cost of electricity before the powerplant is constructed. The cost of building a nuclear power plant and any financing cost is the most important contributing factor to the cost of from nuclear power plants. Although modern nuclear power plants are generally large and expensive, their long project lifetime effectively reduces the cost of nuclear power can still be relatively low. Nuclear energy has generally been regarded by public opinion as a harmful energy resource.  The growing concerns over global climate change and greenhouse gas emissions have changed this belief and nuclear is now considered   a reputable green power source that can generate significant amounts of energy with low carbon emissions. Nuclear energy is currently a mature low-GHG emission energy resource that is ideal for use as baseload power. However, the share in global electricity generation has been declining globally but its share of global electricity generation has been declining since the year 1993 because of various barriers and risks. The life cycle GHG emissions from nuclear power are less than traditional fossil sources but assumptions and conditions under which they are deployed can have serious impact on the magnitude of life cycle GHG emissions compared to renewable technologies. The published median, interquartile range (IQR), and range for LWR life cycle GHG emission are 13, 23, and 220 grams of carbon dioxide equivalent per kilowatt-hour (g CO2-eq/kWh), respectively. Upon application of harmonizing methods to use consistent gross system boundaries and values important system parameters yielded 12, 17, and 110 g CO_2-eq/kWh, respectively. Based on ongoing improvements, median life cycle GHG emissions could be 9 to 110 g CO2-eq/kWh by 2050