Slovenia’s nuclear sector is small in physical scale but large in strategic importance. The country operates only one commercial reactor, yet the Krško Nuclear Power Plant is one of the most important sources of electricity for both Slovenia and neighboring Croatia. It supports grid stability, limits the need for fossil-fuel imports and provides low-carbon power in all seasons.
The plant is a pressurized water reactor with a net electrical capacity of about 696 megawatts. It entered commercial operation in 1983 and normally produces around 5.7 terawatt-hours of electricity per year. Nuclear energy often provides roughly one-third of Slovenia’s electricity, although its share changes with hydropower output, demand and plant outages.
Krško is jointly owned by Slovenia’s GEN energija and Croatia’s Hrvatska elektroprivreda. Each company holds a 50 percent interest, and the output is divided between the two countries. This arrangement makes Krško both a national power station and a long-running cross-border energy project.
Krško Has Entered Its Extended Operating Life
Krško completed its original 40-year operating period in 2023 and received the approvals needed to continue operating for up to 60 years, placing its expected closure date in 2043. Continued operation remains subject to maintenance, modernization, regulatory reviews and periodic safety assessments.
The life-extension program has included equipment upgrades and safety improvements based on international operating experience. The plant has also transferred part of its used fuel from the spent-fuel pool into dry storage, increasing capacity and strengthening long-term fuel management at the site.
Krško’s performance matters because Slovenia cannot replace such a large source quickly. A prolonged outage can increase electricity imports and place pressure on the national balance. At the same time, continued operation gives the country more time to expand renewable energy, strengthen the grid and decide what should follow the present reactor.
The extension to 2043 is therefore a bridge rather than a permanent answer. A large nuclear project requires many years of planning, licensing, financing and construction, so the replacement decision cannot be delayed until the existing unit approaches closure.
JEK2 Moves Into Formal Spatial Planning
The proposed second unit at Krško, known as JEK2, is the central question in Slovenia’s long-term nuclear policy. GEN energija is developing the project beside the existing plant, where transmission connections, emergency-planning systems, nuclear expertise and an experienced workforce are already available.
The project entered a more formal stage in February 2026, when the government initiated preparation of a National Spatial Plan. The process will cover the reactor and associated infrastructure, including cooling, grid connections, transport requirements and environmental effects. The government expects the spatial-planning decree to be completed in autumn 2028.
GEN energija has focused technical work on several large pressurized water reactor options, including Westinghouse’s AP1000 and designs offered by EDF. No final technology has been selected, and JEK2 remains a development project rather than a plant under construction.
Any leading option would be substantially larger than the existing Krško unit. That could reduce import dependence and support future electrification, but it would also require careful planning for financing, transmission, reserve capacity and periods when the new reactor is offline.
The Project Must Prove Its Economic Case
JEK2 will be judged as much by its financial structure as by its engineering. Large reactors require high initial capital spending, long construction schedules and strong project management. Slovenia must decide how the plant would be financed, how construction risks would be divided and whether Croatia or other regional partners would participate.
The project could create skilled employment and work for domestic suppliers. However, local benefits will depend on how much construction, engineering and long-term service work Slovenian companies can perform. Specialized reactor components would still come from an international supply chain.
Electricity-market design is another issue. A nuclear plant can provide stable output for decades, but investors need confidence that revenues will cover financing and operating costs. Possible models may include state support, long-term power contracts, regulated payments or participation by large electricity buyers.
Slovenia must also compare JEK2 with a wider system based on renewables, storage, imports, demand management and grid investment. The government presents nuclear and renewable energy as complementary, but the cost and timing of each part will determine whether that combination is practical.
Public Consent Became a Central Project Risk
Slovenia planned a consultative referendum on JEK2 for November 2024, but parliament cancelled the vote after disputes over its wording, legal process and the quality of information available to voters. The cancellation did not end the project, but it showed that broad political support does not automatically create public legitimacy.
A future national decision will require clearer information about reactor size, cost, financing, ownership, waste management and alternatives. Approval of a general nuclear policy is different from approval of a defined investment with known financial responsibilities.
Technical studies and licensing preparations can continue before a final construction commitment. This allows the proposal to become more specific, but it also makes transparency during development essential. Public confidence will depend on whether costs, risks and alternatives are presented before the decisive political stage.
Krško’s long presence may help local acceptance. The plant supports employment and municipal development in the Posavje region. Even so, national concerns about financing and governance will remain central.
Waste Management Must Advance With the Program
Slovenia is developing a repository at Vrbina near Krško for low- and intermediate-level radioactive waste. Progress is important for the existing plant and for the credibility of any expansion. Slovenia and Croatia remain responsible for their respective shares of Krško’s waste and decommissioning obligations.
Dry storage has reduced pressure on the spent-fuel pool, but it is not a final disposal solution. Building JEK2 would increase the amount of used fuel and extend Slovenia’s waste-management duties far beyond the operating life of the current reactor.
The country also maintains nuclear research and technical skills through the Jožef Stefan Institute and its TRIGA research reactor. These institutions, together with Krško and the national regulator, provide a strong knowledge base. A new large reactor would still require workforce growth and long-term training.
Slovenia’s Nuclear Future Depends on the Quality of the Decision
Krško gives Slovenia a reliable nuclear foundation through 2043, while JEK2 advances through spatial planning, technical studies and environmental preparation. No final investment decision has been made.
The project will depend on whether Slovenia can define a credible cost, financing model, reactor design and public decision process before the current plant approaches retirement. If those elements align, nuclear energy could remain central to Slovenia’s electricity system for the second half of the century. If they do not, the country will need a much faster expansion of other domestic generation, storage and cross-border supply.