Key determinants of nuclear fission competitiveness and implications of its potential restart for the Italian power system

This study introduces two key methodological enhancements to an open-source multi-regional model of the Italian power sector, namely a detailed representation of the nuclear fuel cycle and a discrete capacity formulation to capture the indivisible nature of reactor units and their systemic interactions, and applies them to assess the techno-economic feasibility and policy conditions under which nuclear fission could re-emerge as a competitive player within an Italian decarbonized power system by 2050. Through a structured scenario analysis, we examine both the combined influence of investment costs and hurdle rates on the competitiveness of nuclear power, comparing large light-water reactors and small modular reactors, and the potential implications of nuclear fission reintroduction for the Italian power system. A dedicated sensitivity analysis investigates the potential of Generation IV designs, such as lead-cooled fast reactors and high-temperature gas-cooled designs, under alternative cost assumptions. The results indicate that nuclear power would become economically viable in most scenarios with stable or moderately increasing capital costs, reaching up to the 8 GWe maximum constraint for the installed capacity by 2050 and reducing electricity imports by nearly 50%. Nuclear deployment would decrease the total system costs by up to €8 billion, while also reducing storage requirements (−42%), curtailed generation (−35%) and land use (−25%) compared to a non-nuclear decarbonization pathway. Overall, the study highlights the decisive role of financing conditions and policy frameworks in determining the future competitiveness of nuclear energy in Italy, emphasizing its potential contribution to energy security, system reliability, and cost-efficient decarbonization.