Status of nuclear energy

As of 2023, over 410 nuclear reactors operate in more than 30 countries, supplying 9% of global electricity and representing the second-largest low-emissions source after hydropower. Nuclear energy has avoided 72 gigatonnes of CO₂ emissions since 1971.

Advanced economies hold over 70% of reactors, though their fleets are ageing—averaging 36 years. France and the Slovak Republic have the highest nuclear shares (65% and over 60%, respectively). By contrast, nuclear capacity is growing in emerging economies, particularly China and Russia, which account for 48 of the 52 new reactors constructed since 2017.

Nuclear is also used for combined heat and power in industrial processes, district heating, and desalination. Around 70 reactors currently provide thermal output. China’s Haiyang and Czechia’s Dukovany II are recent district heating projects. Construction timelines in advanced economies are long and often exceed a decade, contributing to high capital costs and delays. By contrast, China averages seven years for reactor builds. Recent projects in Korea and the UAE have demonstrated more efficient execution. Global nuclear investment reached USD 65 billion in 2023, nearly double the level a decade earlier. Investment includes both new construction and lifetime extensions.

Policy support has expanded. More than 40 countries plan new reactors or are considering nuclear energy. Lifetime extensions have been approved in 13 countries, covering around 65 GW. Nations including the United States, France, Japan, and several EU member states have introduced specific funding mechanisms and regulatory adjustments.

Small modular reactors (SMRs) are central to renewed interest. Over 80 SMR designs are under development. Leading developers include NuScale, Westinghouse, GE Hitachi, and CNNC. SMRs are suited to replace fossil fuel plants, with reduced upfront costs and shorter construction times. Some are tailored for district heating or desalination.

Data centres are emerging as a dedicated market, with up to 25 GW of SMR capacity announced, mainly in the US. Operators seek reliable, low-emissions electricity to meet uptime and sustainability requirements. Some data centres are pursuing SMR-powered projects or restarting retired reactors.

Japan has restarted 14 of 54 reactors shut down after 2011. Additional units are under review, with public acceptance and regulatory compliance playing key roles.

Outlook for nuclear investment

• Under the Stated Policies Scenario (STEPS), nuclear capacity increases from 416 GW in 2023 to 650 GW by 2050. In the Announced Pledges Scenario (APS), capacity reaches 870 GW; in the Net Zero Scenario (NZE), it exceeds 1,000 GW.
• Investment rises to USD 70 billion by 2030 in STEPS, USD 120 billion in APS, and USD 155 billion in NZE. SMR investment grows from under USD 5 billion today to USD 25 billion in APS by 2030, reaching USD 670 billion by 2050.
• Advanced economies see limited growth due to ageing fleets. China’s nuclear capacity is set to triple by 2050 and overtake the US by 2030. SMRs could represent over 20% of new capacity if cost reductions align with policy and regulatory support.
• Construction costs are projected at USD 10,000/kW for first-of-a-kind SMRs in advanced economies, falling to USD 4,500/kW by 2040. Some developers aim for lower targets (e.g., USD 2,250/kW for GE Hitachi).

Financing nuclear projects

Nuclear financing remains challenging due to long timelines, capital intensity, and complexity. SOEs continue to play a major role. Private sector interest is growing, especially in SMRs, which offer lower investment thresholds and faster returns.

Cost predictability and standardisation are essential to attract finance. De-risking tools such as long-term power purchase agreements, contracts for difference, and regulated asset base models improve financial viability. Green bonds and new tariff structures are also being explored.

Governments are advised to ensure strategic support, robust regulation, skilled workforce planning, and diverse supply chains. Greater diversification in uranium supply and enrichment services is required, given current concentration in a few countries.