Nuclear Energy Development and Energy Security in Slovakia: Current Status and Conditional Prospects up to 2050

This article evaluates how nuclear energy development may affect energy security and nuclear energy security in Slovakia up to 2050. It applies a qualitative-dominant mixed-method design combining critical source-position appraisal, a claim-evidence matrix, quantitative reconstruction of the 2021–2024 electricity balance, comparison of three official 2040 adequacy scenarios, stress tests for a 1200 MW large reactor and a 300 MW small modular reactor (SMR), and negative-case analysis. The results show that Slovakia entered 2024 as a net electricity exporter after Mochovce Unit 3 increased nuclear generation, while electricity consumption remained 3.1 TWh below 2021. The decline from 2021 to 2022 reflected a combination of the energy-price shock, industrial demand curtailment, lower fossil generation and hydrological variability rather than a single structural factor. Official 2040 scenarios project gross generation of 43.9–48.5 TWh, of which nuclear contributes 24.2–26.7 TWh, approximately 55%. Adding a 1200 MW unit would generate about 8.4–10.0 TWh annually at capacity factors of 80–95%, creating a material need for demand growth, exports, storage, nuclear heat, hydrogen or load-following operation. The analysis therefore does not treat the Bohunice project or SMRs as inevitable. Their contribution to energy security is conditional on financing, licensing, fuel diversification, grid flexibility, heat off-takers, climate-resilient cooling, radioactive-waste governance, workforce continuity and transparent public governance. A diversified pathway combining safe long-term operation of existing units, renewables, wind development, storage, demand response and selective nuclear investment is more robust than a single-project strategy.