SMALL MODULAR REACTORS AND FLOATING NUCLEAR POWER PLANTS: CURRENT STATUS AND PROSPECTS FOR DEVELOPMENT

Global nuclear energy is witnessing a measurable resurgence as a strategic solution for climate mitigation and energy security, after decades of decline, during which its share of global electricity generation fell to 8.85% in 2025, less than half the peak reached in 1996. Within this context of renewed interest, Small Modular Reactors have emerged as one of the most promising technological avenues, thanks to their modularity, factory-based manufacturing, advanced passive safety features and lower capital investment compared to large-scale nuclear power stations. This thesis aims to assess the current development status of SMRs and their offshore application through Floating Nuclear Power Plants (FNPPs). The work is structured in three parts. First, it reviews the physical fundamentals of nuclear fission, the main components and classifications of reactor types, and the evolution from Generation I to Generation IV, with specific focus on the four main SMR design families (light-water, fast liquid-metal, high-temperature gas-cooled and molten-salt reactors). Second, drawing on the IAEA's Advanced Reactor Information System, it presents a state-of-the-art analysis of 62 SMR projects currently under development worldwide. Third, it reconstructs the Rankine cycle of the Westinghouse AP1000's secondary circuit using the CoolProp library, deriving state points, entropy and enthalpy values and generating T-s and h-s diagrams, validated against published technical data. The results show that pressurised water reactors dominate the current SMR landscape (32.3% of projects), while the sector remains at an early stage of commercial maturity, with only four reactors currently in operation; the thermodynamic model yields an overall plant efficiency of 30.19%, consistent with real-plant data. The thesis then extends the analysis to FNPPs, examining barge-based and offshore platform configurations, the operational case of the Akademik Lomonosov, and emerging applications such as hydrogen and ammonia production. The study is limited to publicly available data from the IAEA database and literature sources, which may not reflect confidential industrial developments; the thermodynamic analysis is restricted to a single reference design (AP1000) under steady-state conditions, and does not include economic or regulatory feasibility assessments, which remain necessary steps toward the commercial deployment of SMRs and FNPPs.