PNNL

Abstract

The uncertainty in the cost of nuclear energy coinciding with efforts to address climate change are contributing to the uncertainty in the future role of nuclear energy in the US electricity system and the response to addressing global climate change. Sensitivity cases of alternative nuclear capital costs, ranging from 2600 to 6600 $/kW, were investigated with scenarios of alternative carbon mitigation policies, including 50, 100, and 150 $/tCO2 carbon tax cases and economy-wide net-zero goals by 2050, 2060, and 2070 for the US. The resulting US nuclear power capacity ranged from 130 to 240 GW in 2050 and 90 to 450 GW in 2100 from nuclear cost sensitivity cases without carbon mitigation policies. Imposing policies to achieve the decarbonization of electricity and net-zero emission goals increased the range of nuclear power capacity from 190 to 460 GW in 2050 and 210 to 850 GW by 2100, where the range is from the low and high nuclear cost cases. Carbon penalties beyond 100 $/tCO2 had a diminishing role on the expansion of nuclear power as the electricity sector becomes fully decarbonized. The 50 $/tCO2 tax had the nuclear capital cost equivalency of 1000 $/kW reduction, while the 100 $/tCO2 tax had the equivalency of 2000 $/kW reduction. Net-zero goals increased the contribution of nuclear power due to the increase in total electricity demand, but the delay in the timing of net-zero did not significantly affect the role of nuclear in the long-term. All net-zero goals were similar in their energy system impact with resulting carbon tax levels reaching 300 $/tCO2. Electricity is fully decarbonized in the net-zero scenarios and carbon pricing beyond 100 to 150 $/tCO2 had little influence on the additional deployment of nuclear power. Regardless of the carbon policy, however, nuclear capital cost reductions had a clear and pronounced impact on the expanded deployment of nuclear power under all scenarios.