What is the future of nuclear power in Ukraine? The role of war, techno-economic drivers, and safety considerations

The TIMES-Ukraine energy system model is used to explore the future of nuclear power plants (NPPs) under an ambitious climate policy scenario, achieving net zero greenhouse gas emissions in 2050. Varying techno-economic (construction costs and capacity factors for NPPs, capital costs for solar and wind), policy (ban on construction or extension of NPPs), and macroeconomic (alternative economic recovery trajectories) factors are considered. The difference in the techno-economic assumptions for nuclear power generation has a very mod-erate impact on the total system costs (TSC) of the energy transition, as their variation (positive or negative change) does not exceed 0.1%-0.2% relative to the default case. Policy decisions on restricting nuclear power generation could have a more substantial impact, as TSC increase by 4-5 billion USD (0.6%-0.9%) over the 2020-2050 period under the most restrictive case. In terms of the economic viability of various NPPs, we find small modular reactors to be more competitive than large NPPs due to the higher availability factor. Overall, in terms of developing new NPP capacities, policymakers can consider alternative futures for this technology without major implications for the energy transition costs, as retired NPPs can be substituted by alternative generation technologies in a cost-competitive manner.