The latest annual report on the nuclear sector, published by the association Nuclear hole, paints a scenario in which Nuclear energy is consolidating its position as a key element to guarantee a stable supply, contain CO2 emissions, and sustain industrial competitiveness. At the same time, it clashes head-on with the official reactor closure schedule agreed upon a few years ago between the power companies and the government.
Nuclear power in 2025: far fewer megawatts, much more production
In terms of power, the Spanish nuclear fleet has 7.117 net electrical megawatts (MWe)In other words, with just over one-twentieth of the total system capacity, these facilities have been able to secure almost one-fifth of the electricity consumed last year.
The Nuclear Forum report underlines that nuclear technology was again the one that operated at full power for the most hours In 2025, Spanish reactors accumulated 7.284 operating hours, equivalent to 83,15% of the annual time. This high load factor highlights their continuous generation nature, especially relevant when other technologies depend on weather conditions.
In addition to its share of total electricity generation, nuclear power has achieved a prominent position in the climate field: 25,56% of all CO2-free electricity generated in Spain In 2025, it came from these power plants. This fact is one of the sector's main arguments for maintaining that extending their lifespan is consistent with decarbonization commitments.
Results of the Nuclear Forum report and its role in the energy transition
The conclusions of the document “Nuclear Results 2025 and Future Prospects” emphasize that the operational and safety indicators of Spanish reactors They are at very high levels. The association highlights a “high level of excellence” both in daily operations and in the protection systems of the facilities.
The president of the Nuclear Forum, Marta Ugalde, uses the report to insist that keep the power plants running It is a strategic tool: it strengthens energy autonomy, contributes to the stability of supply and helps to progress towards climate goals without driving up electricity costs.
In his message, Ugalde argues that the prolonged operation of the reactors “It is not only viable, but a safe and strategic decision"provided that the required safety standards are maintained." He emphasizes that the combination of nuclear and renewables has been key to containing prices and reducing exposure to recent energy crises.
The Nuclear Forum points out that, in 2025, the Spanish nuclear fleet was once again "the technology that operates the most hours per year," something it considers fundamental while there is no massive deployment of storage and networks that allows managing large volumes of renewable generation without firm backup.
The association argues that having reactors operating during the transition allows progress towards a low-carbon economy without jeopardizing security of supply or the competitiveness of energy-intensive industries, which depend on reasonable prices and stability in the cost of energy.
Closure schedule and the push for the Almaraz extension
Despite the positive results for 2025, the official roadmap remains the gradual closure of nuclear power plants. The agreement signed in 2019 between the owning companies and the government establishes a phased shutdown of all reactors between 2027 and 2035, which would mean completely abandoning nuclear power in just over a decade.
According to that schedule, Almaraz I should be decommissioned in 2027 and Almaraz II in 2028; they would be followed by Ascó I and Cofrentes in 2030; Ascó II in 2032; and finally Vandellós II and Trillo in 2035. If nothing changes, No Spanish reactor would exceed 47 years of operationThis contrasts with what is happening in most countries with nuclear power plants.
The main point of contention now revolves around the Almaraz nuclear power plant in Extremadura. On October 30, 2025, the Board of Directors and the Assembly of Shareholders of the Almaraz-Trillo Nuclear Power Plants formally requested the Ministry for Ecological Transition the modification of the current authorization to extend the operation of its two units until June 2030.
This request directly challenges the timetable established in 2019 and has opened a new chapter in the Spanish energy debate. For the time being, the government is referring to the opinion of the Nuclear Safety Council (CSN) before ruling on the extension, insisting on the need to prioritize technical and safety criteria in any decision.
Meanwhile, several European institutions have focused their attention on the case. The European Parliament's Committee on Petitions has urged the Spanish government to keep Almaraz operational and has warned that its closure could worsen the instability of the electricity system, in a context where there is already concern about the balance between supply and demand.
Renewables, security of supply and political debate
While the nuclear sector tries to consolidate its role, the Government maintains that The country's strategic priority is renewable energy.The Secretary of State for Energy has reiterated in various forums that renewable technologies are the ones that "make the most sense" for Spain and that he considers the most competitive in the medium and long term.
The Executive branch emphasizes that in recent years the strong incorporation of renewables And the displacement of imported fossil fuels has strengthened Spain's energy position in the face of international crises. However, the nuclear industry points out that these sources are intermittent and that, to this day, they still require robust backup until large-scale storage is developed.
The differences in approach are evident in public discourse. While energy authorities insist on prudence and allowing the Nuclear Safety Council (CSN) to do its work before deciding on the lifespan of nuclear power plants, the nuclear sector emphasizes that Their technology operates for many more hours per year. and that, without the current tax burden, it could be even more competitive.
The issue of costs is also part of the debate. The government states that any potential extension of the plants' lifespan will only be considered if It does not entail an increase in the electricity bill or the tax burden....and provided that the safety of people and the environment is preserved. For its part, the industry argues that nuclear power is one of the cheapest and most predictable options, especially when considering its long lifespan.
This clash of visions occurs at a time when the The European Commission has begun to describe it as a “strategic error” The premature closure of nuclear power plants in some countries. Brussels emphasizes the value of this technology in guaranteeing competitive prices, reducing foreign dependence, and facilitating long-term electricity system planning.
The international context: more reactors, longer licenses, and a nuclear renaissance
The Nuclear Forum report places the Spanish situation within a global landscape in full reconfigurationBy the end of 2025, there were 413 reactors in operation spread across 31 countries and another 70 under construction in 15 different countries. In recent years, global nuclear power generation has remained around 2.700 terawatt-hours (TWh), approximately 9% of global electricity demand.
In terms of emissions, this nuclear production represents approximately one third of the world's CO2-free electricityThis largely explains why numerous countries are reconsidering their energy strategies. The International Energy Agency is already speaking of a “new era” for this sector, driven by the need to strengthen security of supply and reduce greenhouse gas emissions.
During 2025, construction began on seven new reactors in countries such as China and Russia, while three other units were connected to the grid in China, India, and Russia. China clearly leads the nuclear expansion, but it is not the only player: A total of 38 countries have endorsed the commitment to triple the world's nuclear capacity by 2050.
The shift in perception also extends to the financial sector. The World Bank has lifted its long-standing restriction on financing nuclear projects, opening the door to new international support. At the same time, many governments are exploring the development of small modular reactors (SMR) as a flexible complement to existing large power plants.
Regarding the lifespan of reactors, the prevailing trend is to extend operating licenses. By the end of 2025, regulators in 15 countries had granted or extended permits for reactors to operate. 142 reactors can operate for at least 60 yearsIn the United States, twenty units already have authorization to operate for 80 years, including twin plants of some Spanish facilities, such as Ascó and Almaraz.
Europe between the energy crisis and strategic autonomy
In Europe, the Russian invasion of Ukraine and the subsequent gas crisis have given nuclear energy a marked geopolitical componentFor many EU capitals, strengthening energy independence has become a priority, and nuclear power has regained prominence as a tool to reduce dependence on imported fuels.
Within the European Union, the Commission has made it clear that it considers it a mistake to rush to close operating nuclear power plants without a fully guaranteed alternative. Both the President of the European Commission and other EU leaders have stressed that abandoning nuclear power hastily It can compromise security of supply and increase electricity prices.
Some countries that opted to do without this technology have already begun a review process. The European debate frequently cites the German casewhere the closure of the last nuclear power plants in 2023 has been described in retrospect as a decision with significant strategic and economic costs.
At the same time, a growing number of Member States are promoting alliances around nuclear energy and demanding that its contribution to climate goals be recognized on par with other low-carbon energy sources. This trend is reflected in discussions on green taxonomy and regulatory frameworks for energy investment within the EU.
Spain, for now, remains in a unique position. While many partners are considering extending the life of their reactors or even building new units, Spain's timeline points to a gradual phase-out of this technology. This contrast fuels the internal debate about whether it is advisable to align with the European "nuclear renewal" or to continue with a model based almost exclusively on renewables.
Economic impact, employment and radioactive waste management
Beyond megawatts and climate statistics, the Spanish nuclear sector also asserts its economic and labor weightCompanies involved in this activity export technology, components, and services to more than 40 countries, relying on the experience accumulated over decades of power plant operation.
In terms of employment, the figures are particularly significant in the areas where the facilities are located. The Almaraz nuclear power plant, for example, supports a large number of jobs in its surrounding area. thousands of direct and indirect jobsMost of the workers are highly qualified, as Marta Ugalde herself points out. For the regions that host these power plants, the continued operation or closure of these facilities has significant socioeconomic implications.
One of the most sensitive points in the nuclear debate remains the management of radioactive waste. After ruling out the construction of a Centralized Temporary Storage Facility to concentrate spent fuel in a single location, Spain has opted for a model of individual temporary storage facilities in each central unit, the so-called ATI-100.
These new local storage facilities are expected to begin operating from 2026 onwards, allowing for the storage of spent fuel once it is removed from the spent fuel pools at the nuclear power plants themselves. In the longer term, the Seventh General Plan for Radioactive Waste foresees the creation of seven decentralized temporary storage facilities additional and the development of a Deep Geological Storage facility, whose implementation is not planned until well into the second half of the century.
The Nuclear Forum argues that the industry has developed robust technical solutions for this challenge and that the country has a long-term plan, although it acknowledges that social acceptance And site selection remains a sensitive issue requiring transparency, participation, and regulatory stability.
Lessons from the April 2025 "zero electricity" and long-term perspectives
The industry report also comes after an event that has marked public opinion: the great blackout of April 28, 2025, known as “zero electricity.” At that time, four Spanish reactors were operating when the total power supply to the peninsula failed, which put the sector to the test. security and response protocols of nuclear power plants.
According to the Nuclear Forum, the facilities automatically activated their protection systems and emergency diesel generators, maintaining safe conditions at all times. The organization uses this event as an example of the technological robustness of the Spanish nuclear park and their ability to react to extreme situations without compromising the safety of people or the environment.
The future of nuclear power in Spain now depends on a complex interplay between political decisions, technical criteria, and market signals. The government is officially maintaining the closure schedule, but the international context, European recommendations, and the growing need for electrification could change it. reopen a debate that many considered settled just a few years ago.
Meanwhile, the industry insists that extending the lifespan of existing power plants is one of the fastest ways to strengthen security of supply, cut emissions and contain costs in an increasingly electrified electricity system exposed to the volatility of fossil fuels.
With nuclear energy providing 19,05% of electricity and more than a quarter of CO2-free generation in 2025, Spain faces a major decision: whether to integrate this technology as a stable support to a system dominated by renewables or move towards its complete withdrawal within the planned timeframes, assuming the challenges that this would entail in terms of security, prices and energy autonomy.
