Nuclear fission techno-economic characterization for energy system models and scenario analysis for Italy

The progressive urgency to mitigate climate change, driven by the increasing concentration of greenhouse gases in the atmosphere and the accelerating global temperature rise, is reshaping energy policies and research priorities worldwide. In this context, nuclear energy is gaining renewed interest as a dispatchable, low-carbon source capable of contributing to the decarbonization of energy systems. This thesis focuses on the possible role of nuclear fission in the future Italian power sector, where nuclear power has been absent since 1987, but is now re-emerging in public and political debate. The work aims at investigating under which economic, technical, and policy conditions nuclear power could become a viable option in Italy. The first step is the detailed modeling of the nuclear fuel cycle, including front-end processes (e.g. uranium import, enrichment, and fuel fabrication), reactor operation, and back-end processes (e.g. spent fuel management and reprocessing). These elements are integrated into a power-sector model instance of the TEMOA (Tools for Energy Modelling Optimization and Analysis) open-source energy system optimization framework, enabling a transparent and reproducible techno-economic assessment. A set of scenarios is constructed to evaluate how variations in key parameters such as investment costs, hurdle rates, and capacity constraints affect the competitiveness of different nuclear technologies, including Generation III+ and Generation IV reactors. In particular, large reactors are the optimal choice when their hurdle rate is 6% or 8%. Conversely, SMRs are generally preferred when their hurdle rate is lower than that of large reactors. The results provide policy-relevant insights into the economic and environmental implications of reintroducing nuclear energy in Italy, quantifying its potential impact on system costs, greenhouse gases emissions, and critical material use. In the most favorable scenario, nuclear technologies provide 15% of electricity demand by 2050, reducing greenhouse gases emissions by up to 17%, while saving approximately 300,000 tons of critical raw materials like Aluminum, Copper, Chromium and Nickel. A sensitivity analysis is performed for advanced SMRs costs to identify relevant thresholds for their competitiveness. By doing so, the thesis contributes to filling key research gaps regarding nuclear energy modelling within open-source energy system tools and supports an informed discussion on the feasibility of nuclear deployment in Italy’s energy transition.