The evolution of nuclear energy from legacy plants to next-gen reactors

Current situation and challenges faced

Nuclear energy has immense potential as a low-carbon energy source. Given the complexity of climate change, it is of the utmost importance to understand the benefits of nuclear energy.

The first nuclear power plant was commissioned in the 1950s. Since then, nuclear power has grown significantly, with over 440 nuclear power reactors in operation worldwide today, providing around 10% of global electricity supply.

In advanced economies, nuclear energy accounts for 18% of generation, making it the largest low-carbon source of electricity. In Europe, nuclear energy shares are even higher and exceeded 20% of EU electricity production in 2022. In nuclear, huge capacities were built up around the 1980s. Around Europe there are already several lifetime extension projects, expanding the lifetime of a nuclear power plant up to 80 years and beyond.

Nuclear energy offers several advantages. It provides steady baseload power without greenhouse gas emissions. It offers predictable and concentrated largescale electricity production. Additionally, the generated heat from nuclear power plants can be utilised for, e.g., district heating or industrial processes. A small mass of nuclear fuel can sustain a reactor for years, ensuring energy security.

Nuclear capacity in Europe has varied recently, partially due to countries’ reactor shutdowns and temporary reactor closures for maintenance. While Germany phased out nuclear power, many European countries continue to invest in lifetime extensions and new reactor projects.

Challenges with new plants relate especially to high cost of investment for a long amortisation period (approx. 60 years) and the challenges to build new nuclear power reactors as budgeted. This overall leads to nuclear facing significant competition from other technologies due to a high levelised cost of electricity resulting from high project costs, as observed from recent installations in Finland, France and the UK. Particularly as development in sustainable energy solutions evolve to provide both large scale and long-term storage to offset intermittent renewables, the cost of new-build nuclear will be challenged by these solutions.

At the COP28, significant commitment related to nuclear energy was made, with 25 countries pledging to triple their nuclear energy capacity by 2050. Additionally, the EU recently underscored nuclear energy's pivotal role in transitioning away from fossil fuels, acknowledging it as a crucial technology for this purpose.

Global installed nuclear capacity in high and low scenarios (GW)

Looking ahead

Rapid climate change and recent geopolitical events have triggered a significant shift in energy policies, with a renewed momentum for nuclear power. In a European context, the Council of EU member states and the European Parliament have labelled nuclear power as a strategic technology for EU’s decarbonisation plan.

Looking ahead, the role of nuclear energy is forecasted to exhibit a modestly increasing trajectory globally which may well become a strong growth. For a tripling of nuclear energy capacity as pledged by 25 countries at the COP28, new large-scale nuclear power plants are necessary. These should provide enhanced reactor efficiency and safety while reducing costs via more standardised designs. Further investments into alternative nuclear technologies, such as small modular reactors (SMRs) or advanced modular reactors (AMRs), along with transformative technologies like fusion reactors, are necessary.

As newly built nuclear power faces cost challenges and exceptionally long investment periods, lifetime extension and power upgrades of existing nuclear power plants are being considered as complementary investments. Secure lifetime extensions of reactors up to 80-100 years are now taking place across Europe to make most of the existing capabilities and to ensure baseload energy production. These extensions involve rigorous safety assessments, component replacements, and adherence to modern standards.

Installed nuclear capacity by country in 2020 versus 2050 in Europe (GW)

SMRs are designed with modularity, allowing them to be factory-assembled and transported as a single unit. This approach not only reduces costs but also facilitates regulatory approval across Europe. While SMRs are sometimes mentioned in the same context as AMRs, it is important to note that AMRs are distinguished by their innovative use of fuels, cooling systems, and other technological advancements, in addition to their modular design. Both offer increased flexibility, enhanced safety and cost effectiveness. While promising technologies such as nuclear fusion are still far away from reaching technological maturity for large-scale deployment, first modular reactors are already starting to be built and their commissioning is planned for the early 2030s.

Back on the agenda in Europe, the future role of nuclear energy is likely to be shaped by a combination of policy decisions, economic factors, and technological advancements. Focused political support and investment in technology are important for both SMRs and traditional-sized nuclear power plants to achieve higher cost-competitiveness by overcoming regulatory hurdles and improving investment conditions. The journey towards decarbonisation is complex, but with strategic planning and innovation, nuclear energy will play a vital role in Europe as a stable and reliable future energy source.

Overview of nuclear reactor types