5 things you should know about nuclear energy

As the European Union continues to phase out polluting fossil fuels, more focus is on low-emissions technologies like nuclear to power our economy. The European Commission works closely with EU countries to uphold the highest standards of nuclear safety, radiation protection, security, and non-proliferation - clear obligations outlined in the Euratom Treaty and related EU legislation.

Here are 5 things you should know about nuclear energy in the EU.

1. Nuclear energy in the EU: almost a quarter of electricity produced in 2024

In 2024, nuclear power plants generated 23.3% of the electricity produced in the EU. Since 2023, electricity generation from nuclear power plants has increased, with a 4.8% year-on-year growth recorded in 2024.

12 EU countries have nuclear power plants in operation: Belgium, Bulgaria, Czechia, Spain, France, Hungary, the Netherlands, Romania, Slovenia (co-owned with Croatia), Slovakia, Finland and Sweden. And in certain EU countries nuclear energy accounted for a significant share of their power production with France (67%) and Slovakia (62%) being the most reliant on nuclear energy for their electricity production (numbers from 2024).

In the Commission's 2040 climate target impact assessment, all zero- and low-carbon energy solutions - including renewables and nuclear - are essential to decarbonising the energy system. The analysis shows that renewable energy in majority, complemented by nuclear energy, will generate over 90% of electricity consumption in the EU by 2040.

2. The decarbonisation baseload: nuclear energy is one of the lowest carbon-emitting sources of electricity

What is most visible about nuclear power plants are the huge 'chimneys', which in fact are cooling towers. From even several kilometres away, they appear to emit big clouds of white 'smoke', which is, in fact, evaporated water.

Nuclear energy is one of the lowest carbon-emitting sources of electricity because it produces virtually no greenhouse gases during operation, only emitting minimal CO₂ over its entire lifecycle (including construction, fuel production, and decommissioning). Renewable and nuclear energy combined make up around two-thirds (65%) of electricity generated in the EU. The combination ensures a stable, low carbon energy mix as nuclear provides a dispatchable baseload power while renewables deliver flexible, variable clean energy together enhancing decarbonisation.

While it is up to EU countries to decide which power sources to use, they have all committed to phasing out harmful fossil fuels. Several EU countries that have included nuclear energy alongside renewable energy sources in their energy mix to diversify energy supplies while minimising greenhouse gas emissions from burning fossil fuels in power plants.

3. Nuclear waste: only spent nuclear fuel and high-level radioactive waste require deep geological disposal

If a single person relied solely on nuclear-generated electricity for their entire lifetime, it would generate about 2 kg of spent fuel, and up to 100 kg of radioactive waste. Spent fuel and 0.2% of radioactive waste volume (high-level radioactive waste), require disposal in deep geological formations in order to ensure long-term safety. For instance, in Finland, the Onkalo deep geological repository is located over 400 meters underground in bedrock.

Radioactive waste is treated and conditioned, and often waste volume reduction measures (like super-compaction) are used. Spent fuel can be reprocessed to recycle re-usable fuel components (like France and Netherlands have chosen to do): this reduces the amount of spent fuel to be managed. However, it should not be forgotten that the by-product of that is also high-level waste, which needs to be disposed of. Advanced reactor concepts could further reduce the amount and long-term radiotoxicity of high-level waste.

Every management step, from transport to final disposal, is carefully monitored and regulated in line with the highest nuclear safety and safeguards standards. National nuclear safety authorities oversee the work of nuclear power plants operators and waste management organisations to secure safe and reliable management of radioactive waste. All EU countries have national programmes for spent fuel and radioactive waste management in place and are continuously developing them.

4. Engineered for safety: nuclear power plants are designed to rigorous safety standards

Protection from radiation is at the heart of the process of designing and operating nuclear power plants. Nuclear power plants in the EU are subject to strict nuclear safety standards, with systems in place to protect workers, the environment and the public.

Nuclear power plants have been in operation for over 50 years, with all the data collected over decades showing no abnormal - or elevated - radiation levels around their sites. Any radiation observed can be compared to, or even lower than, those from natural background radiation such as sun rays, radioactive minerals present on earth, medical imaging or air travel. Nuclear technology is also advancing, with new designs integrating cutting-edge safety innovations.

Naturally, there has been public concern around the safety of nuclear power plants, not least with the accidents in Chornobyl (1986) and Fukushima (2011). In the wake of Fukushima, the EU introduced rigorous nuclear safety assessment (stress tests) for all nuclear reactors, assessing resilience against extreme natural hazards, and other risks. The Euratom legal framework has also evolved to reflect the lessons learned and the principle of continuous improvement of nuclear safety. Regular peer reviews and transparency requirements further reinforce accountability across EU countries.

Statistically, nuclear power is safer than many other energy sources, with fewer workplace accidents or fatalities. According to the OECD, coal accounts for most of fatalities in energy-related accidents, followed by oil and gas.

5. Nuclear fusion: Replicating the power of the sun on earth

Unlike nuclear fission, which splits atoms, nuclear fusion is a process which aims to combine them, just like what powers the sun. Scientists have made remarkable progress over the past 60 years to master nuclear fusion in terrestrial conditions. Research has focused on improving fusion reactions to narrow down most promising technologies, and there is now a global race to develop a commercial fusion power plant and connect it to the grid.

The EU is the biggest contributor and host to the world's largest experimental fusion reactor, ITER, which is currently under construction in southern France. ITER aims to demonstrate that a large-scale fusion reactor can produce more energy than what it needs to operate, so proving the feasibility of the peaceful use of nuclear fusion for power generation.

A fusion reactor does not produce any long-lived high-level radioactive waste, and it is inherently safe to operate - if power is lost, the fusion process simply stops, as it requires a steady external energy input to run.

While there are still important challenges to overcome to make fusion a commercially viable energy source, such as the production of Tritium fuel and the net positive energy production, its technology makes fusion very attractive: it is decarbonised, inherently safe, sustainable on the long term and would permit energy independence.

Source List

Introduction

• Euratom Treaty

1. Nuclear energy in the EU: almost a quarter of electricity produced in 2024

• Publication: Energy in Europe - 2026 edition
• Commission staff working document: Impact Assessment Report
• 2040 climate target - Climate Action

2. The decarbonisation baseload: nuclear energy is one of the lowest carbon-emitting sources of electricity

• Publication: Energy in Europe - 2026 edition
• Article: What are the safest and cleanest sources of energy?

3. Nuclear waste: only spent nuclear fuel and high-level radioactive waste require deep geological disposal

• Radioactive waste and spent fuel
• Council Directive 2011/70/EURATOM
• Report: Progress of implementation of council directive 2011/70/euratom and an inventory of radioactive waste and spent fuel present in the community's territory and the future prospects
• Article: Your lifetime used fuel would fit in a soda can! Want proof?

4. Engineered for safety: nuclear power plants are designed to rigorous safety standards

• Nuclear safety
• Report: Comparing Nuclear Accident Risks with Those from Other Energy Sources
• Article: What are the safest and cleanest sources of energy?
• European Radiological Data Exchange Platform

5. Nuclear Fusion: Replicating the power of the sun on earth

• ITER