Nuclear generation hits record high as countries push for energy security

Global nuclear electricity generation reached a record 2,702 terawatt-hours (TWh) in 2025, marking a second consecutive annual high as countries increasingly turn to nuclear power to strengthen energy security and resilience. According to the World Nuclear Association's latest World Nuclear Outlook Report, reactors generated 35 TWh more electricity in 2025 than the previous year, while the global fleet maintained a strong average capacity factor of 83.7%. This achievement comes amid growing support for nuclear energy across governments, and the report found that political support, institutional capacity, and infrastructure readiness are improving across many countries. As a result, 38 countries have now endorsed a goal first agreed at COP 28 to triple global nuclear capacity by 2050. 'This is an extraordinary moment for nuclear energy. Reflecting on another year of record performance, and looking ahead to a future of record ambition, governments are clear: they need much more nuclear energy to address the interconnected challenges of energy security, affordability, competitiveness, and climate goals.' - Dr Sama Bilbao y León, Director General of World Nuclear Association The Association estimates that national targets, identified projects and continued operation of the existing reactor fleet could deliver around 1,457 gigawatt-electric (GWe) of nuclear capacity by 2050, exceeding the tripling target by more than 200 GWe. 'This is an extraordinary moment for nuclear energy. Reflecting on another year of record performance, and looking ahead to a future of record ambition, governments are clear: they need much more nuclear energy to address the interconnected challenges of energy security, affordability, competitiveness, and climate goals,' said Dr Sama Bilbao y León, Director General of World Nuclear Association, commenting on the report ahead of the World Nuclear Symposium in London. However, the report warns that a significant gap remains between government ambitions and projects moving through the development pipeline. From ambition to delivery The report found that more than 550 GWe of capacity needed to meet published government targets is not yet represented by projects, whether under construction, planned or proposed. This underlines the scale of investment and supply chain expansion still required. According to Dr León, ambition alone will not deliver round-the-clock clean energy, and it must be matched by action. 'That's why the Association has published recommendations that set the path towards tripling global nuclear energy capacity by 2050,' she said, adding that 'We need to make full use of the existing fleet, complete reactors already under construction [while] capitalising on the acquired capabilities, commit to the next projects, and move from individual projects to sustained programmes of deployment.' New builds gain traction Some of these recommendations from the Association can already be seen in action. Nuclear capacity under construction rose to 82 GWe in 2025, with work beginning on 11 new reactions during the year. Planned, proposed, and potential capacity also increased to 416 GWe, narrowing the gap between actual projects and government targets. The Association expects reactors already under construction to add 54 GWe of capacity by 2030, followed by a further 28 GWe by 2035. Growth is also expanding beyond traditional nuclear markets. Of the projected 1,457 GWe of capacity in 2050, around 1,303 GWe would be located in countries that already operate nuclear power plants, while newcomer countries could account for 154 GWe. Existing reactors remain vital The report highlights lifetime extensions for existing reactors as one of the fastest and most cost-effective ways to maintain low-carbon electricity supplies while new capacity is brought online. Today, nuclear power generates roughly 9% of global electricity from about 440 reactors operating in 31 countries and provides more than one-fifth of the world's low-carbon electricity. According to the Association, nuclear generation has avoided 43.6 billion tonnes of CO 2 emissions compared with gas-fired power since 1970, and 97.2 billion tonnes compared with coal. With policy support building globally, the industry's challenge now is to convert long-term targets into bankable projects and sustained construction programmes capable of delivering the nuclear capacity required by 2050.