You can read this and more in the magazine Amidst the global climate crisis, many businesses and consumers are searching for more sustainable energy sources, such as wind, solar or nuclear power. Nuclear energy produces zero carbon and is the second-largest source of low-carbon energy in the world, behind hydropower. Today, there are approximately 440 commercial nuclear power reactors operating in more than 30 countries, providing around 400 GWe of total energy capacity. The US is the largest nuclear energy producer in the world, with 781,945 GWh of nuclear electricity in 2024. Sustainability Magazine presents a list of the Top 10 nuclear energy companies across the globe, ranked by their market capitalisation. 10. NuScale Power Market cap: US$3bn CEO: John Hopkins HQ: Tigard, Oregon, US NuScale Power has created 12 energy exploration centres, which aim to train the next generation of engineers. These centres offer a hands-on opportunity to apply nuclear science and engineering principles through simulated, real-world nuclear power plant operation scenarios. John Hopkins, President and CEO of NuScale Power, says: “We remain the first and only SMR technology to have received design approval from the US Nuclear Regulatory Commission, including our uprated 77MWe NuScale Power ModuleTM, placing us at the forefront of advanced nuclear.” Market cap: US$8bn CEO: Jacob DeWitte HQ: Santa Clara, California, US Oklo’s operations focus on designing and deploying advanced fission power plants to provide clean, reliable and affordable energy. It has nine active projects across five US states, including a powerhouse, test facility, radiochemistry lab and advanced fuel centre. Its operating model is designed to integrate power generation, fuel supply, recycling and long-term operations. The company aims to support customers who are seeking reliable clean energy while helping strengthen the domestic advanced nuclear supply chain. Market cap: US$15bn (nuclear division) CEO: Scott Strazik HQ: Cambridge, Massachusetts, US GE Vernova Hitachi Nuclear Energy has been working on advancing nuclear technology for more than 60 years. Its integrated approach to building nuclear power covers reactor configuration, fuel and lifecycle services. Through these, it aims to help customers reduce risk, improve performance and accelerate nuclear deployment. The alliance combines GE Vernova’s design expertise with Hitachi’s experience in advanced modular construction, offering customers technological leadership to advance reactor performance, power output and safety. 7. BWX Technologies (BWXT) Market cap: US$16bn CEO: Rex Geveden HQ: Virginia, US BWXT aims to provide safe, reliable solutions that power communities, industries and critical infrastructure around the world. The company says that “small modular reactors (SMRs) and microreactors are transformative technologies that will play a vital role in meeting the growing demand for clean energy”. It focuses on enhanced safety, simplified operation and efficient fuel utilisation within the development and deployment of nuclear technologies. BWXT invests in research, development and manufacturing for a more sustainable future. 6. China National Nuclear Corporation (CNNC) Market cap: US$27bn CEO: Shen Yanfeng HQ: Beijing, China CNNC has more than 20 nuclear units in operation, as well as offering a portfolio of management service products. This includes preparation, commissioning, refueling outage, maintenance, training and technological support. It has a complete industrial chain for nuclear power plant construction, which involves installation capabilities, maintenance expertise and site accommodation. In addition to its nuclear capabilities, CNNC is working on the strategic deployment of new energy resources, including wind power and photovoltaic power generation. Market cap: US$40bn CEO: Tim Gitzel HQ: Saskatchewan, Canada Cameco’s energy services are used by utilities across the globe, providing nuclear fuel solutions for the generation of safe, reliable, carbon-free nuclear power. It has provided nuclear fuel products and technologies for nearly 40 years. Tim Gitzel, CEO of Cameco, says: “As energy security takes the front seat, we cannot lose sight of the global need to mitigate our collective impacts on climate change and prepare for the changes we are already experiencing.” Market cap: US$54bn CEO: Jim Burke HQ: Irving, Texas, US Vistra operates the second largest fleet of competitive nuclear power plants in the US. The company is working towards net zero carbon emissions by 2050. In January 2026, Vistra announced that it had entered into 20-year PPAs to provide more than 2,600 MW of nuclear energy to support Meta’s operations. Jim Burke, CEO of Vistra, said: “Importantly, this commitment from Meta provides Vistra the certainty needed to invest in these plants and communities and bring new nuclear generation online for the grid – through uprates at our existing plants.” 3. Électricité de France (EDF) Market cap: state-owned, US$60bn equivalent CEO: Bernard Fontana HQ: Paris, France EDF operates 57 nuclear reactors across 19 power plants in France, supporting the country’s energy transition. The company aims to build a net zero energy future with electricity, solutions and services.

Approximately 95% of EDF’s energy production is free from carbon dioxide emissions. In the UK, EDF aims to lead the transition to an electric Britain, as the largest generator of zero carbon electricity in the country. Its stations have generated enough electricity for all homes in the UK for more than 19 years. 2. Constellation Energy Market cap: US$93bn CEO: Joseph Dominguez HQ: Baltimore, Maryland, US Constellation Energy operates the largest fleet of nuclear facilities in the US, working to support grid reliability and energy security. Its nuclear fleet stayed online for 94.7% of the time in 2025, becoming a reliable source of energy for communities across the country. The company invests in capital projects to improve and modernise equipment at its plants. Its investments into nuclear facilities help expand economic opportunities for local communities, hiring an average of 600 people annually into stable jobs. Constellation also supports local communities and causes with charitable giving and sponsorships. Joseph Dominguez, President and CEO of Constellation, says: “With the nation’s largest nuclear fleet at the core of our strategy, we’re pairing the grid’s most reliable power with flexible resources to meet accelerating demand driven by electrification and the data economy.” Market cap: US$99bn CEO: Harry Sideris HQ: North Carolina, US Duke Energy operates 11 nuclear units at six sites across North Carolina and South Carolina, US. These facilities can generate approximately 10,700 MW of electricity, which is around half of the electricity for customers in the Carolinas. Duke’s Oconee Nuclear Station is the company’s largest station, with three generating units which produce more than 2,500 MW. It has set industry benchmarks in safety, efficiency and cost effectiveness across its more than 50 years of operation. Katie Aittola, SVP of Supply Chain, Real Estate and Chief Procurement Officer at Duke Energy, says: “Powering America’s future starts with investing in the people, businesses and communities building it. “By working with American suppliers, Duke Energy is helping deliver reliable service and value for customers while reinvesting customer dollars in the local economies we serve.” Company portals BWX Technologies (BWXT) BWX Technologies (BWXT) Cameco Corporation Cameco Corporation China National Nuclear Corporation China National Nuclear Corporation Constellation Energy Constellation Energy Bernard Fontana Bernard Fontana Harry Sideris President and Chief Executive Officer President and Chief Executive Officer Jacob DeWitte Co-Founder and CEO Co-Founder and CEO Jim Burke President and CEO President and CEO John Hopkins President and Chief Executive Officer President and Chief Executive Officer Joseph Dominguez President and Chief Executive Officer Constellation Joseph Dominguez President and Chief Executive Officer Constellation Rex Geveden CEO Scott Strazik Chief Executive Officer Chief Executive Officer Shen Yanfeng President Tim Gitzel President and Chief Executive Officer President and Chief Executive Officer