Global electricity demand rose by 4.3% in 2024 highlighting the growing pressure on energy systems worldwide. Nuclear power played a vital role in meeting this demand, covering 9% of global electricity generation demonstrating its potential as a reliable, low-carbon power source.
Unlike fossil fuels, nuclear fission does not emit CO₂ during operation. Over the past 50 years, it has helped avoid nearly 70 Gt of CO₂ emissions. By providing steady, high output electricity, nuclear power supports energy security while contributing to the global climate transition.
This article introduces the concept of nuclear fission and explores the structural, financial, and regulatory challenges to its large-scale adoption.
What is nuclear fission?
Nuclear fission power is electricity generated through the controlled release of energy that holds the centre of atoms together. A fission reaction begins when a neutron strikes the nucleus of the atom. The nucleus splits into smaller fragments, releasing energy and additional neutrons. These neutrons trigger more reactions, creating a self-sustaining chain reaction. This process is called nuclear fission.
The heat released from fission is used to produce steam, which drives turbines to generate electricity. This allows nuclear power plants to deliver large scale, low carbon energy.
Barriers to nuclear fission deployment
In 2024, nuclear reactors produced 2,667 TWh of electricity, up 66 TWh from 2,601 TWh in 2023, the highest annual output on record. Despite this milestone, the widespread adoption of nuclear power remains a challenge.
High capital costs
Large-scale nuclear projects demand substantial upfront investment, often reaching several billion dollars per plant. Conventional reactor designs are complex, resource-intensive, and require advanced safety and control systems.
Capital costs account for nearly 60% of a plant’s levelized cost of electricity (LCOE is defined as the total cost to build and operate a power plant over its lifetime, divided by the total electricity produced during that period).
Capital costs include site preparation, construction, manufacturing, commissioning, and financing. A typical nuclear facility requires thousands of workers, large volumes of steel and concrete, and multiple systems for cooling, ventilation, and control.
In France, state-owned utility EDF plans to build six new reactors by 2050 and the project’s estimated cost has risen from €51.7 billion to €67.4 billion ($73.2 billion), highlighting the persistent escalation in nuclear construction costs.
Long lead times
Nuclear power plant construction often spans a decade or more. These lengthy delays can significantly increase costs due to inflation, regulatory changes, and other unforeseen factors.
Persistent delays, cost overruns, and project cancellations have limited nuclear energy’s contribution to rapid decarbonization. Data show that most projects under development are unlikely to begin operation before the next decade undermining their potential role in meeting the 1.5°C target.
Limited new construction since the mid-1980s has increased the average age of global reactors, often beyond their original design life. Many governments have chosen to extend the operation of existing facilities rather than commit to politically and financially demanding new builds.
Ageing reactor fleets
Most operating reactors in advanced economies are more than 36 years old, demanding costly life extensions or replacement programs. Nearly 90% of the 109 reactors currently functioning across the UK and EU have surpassed or are nearing the end of their original design life. This raises difficult questions about the safety, reliability, and economic viability of continued operation.
Retirements continue to reduce total operating capacity, while maintenance challenges and unplanned outages weaken energy output. Physical degradation affects reactor cores, cooling systems, concrete structures, and electronic equipment. Prolonged exposure to ionizing radiation accelerates wear and reduces safety margins.
These cumulative factors often determine whether a plant can safely continue operating or must be decommissioned. The high cost and technical complexity of refurbishing older reactors compel governments to balance between extending existing plants and investing in building new reactors.
Water usage
Nuclear power plants require large volumes of water for cooling and steam generation which make them vulnerable to water scarcity and temperature changes. In arid regions or during heatwaves, nuclear plants may need to reduce output or temporarily suspend operations affecting electricity supply.
A recent example in France highlights this risk. Receding water levels in the river and rising temperatures forced EDF to cut power generation despite rising demand.
Project delays and cost overruns
Many new nuclear plant construction have struggled to deliver projects on schedule and within budget. Beyond high upfront costs, it can take a decade or more to bring a nuclear power plant from conception to operation, during which inflation, policy shifts, or financing constraints can significantly overshoot the initial budget.
Nuclear projects also operate under stringent regulatory and licensing frameworks. Each stage ranging from site selection to design approval and safety certification which add to the cost of running a nuclear plant.
Additionally, decommissioning at the end of a plant’s life is costly and intricate, involving safe dismantling, radioactive material management, and site restoration. These financial burdens, from construction through to decommissioning.
Limited R&D funding
Nuclear energy research and development has declined sharply since the 1970s. In 2015, nuclear energy received only 20% of public energy R&D budgets, down from 73% in 1975. In contrast, research in renewables and energy efficiency now capture larger shares of funding.
Developing and deploying new technologies, such as small modular reactors (SMRs) requires research investment and a secure market. Limited R&D spending constrains innovation, slows technology maturity, and hinders the growth of nuclear as a competitive, low-carbon energy source.
Supply chain concentration
Global uranium mining and enrichment capacity are concentrated in a few countries, creating geopolitical and supply risks. Limited local supply chains and the inability to procure materials at scale further drive up project costs.
Although uranium is relatively abundant, its conversion and enrichment are complex, energy-intensive processes dominated by a small number of suppliers. Dependence on imported enriched uranium leaves many nations vulnerable to trade disruptions and political tensions.
Public perception and opposition
Public opposition remains a major barrier to nuclear expansion. Concerns over safety, radioactive waste, and past accidents reinforce fears about reliability and long-term risks. The potential for human error or natural disasters cannot be dismissed.
Radioactive waste management also remains unresolved, as spent fuel stays hazardous for thousands of years. The absence of permanent disposal solutions and public mistrust of nuclear governance have slowed new project approvals.
The path forward for nuclear fission
For the first time, nuclear power accounted for 9% of global electricity generation in 2024 making it the second-largest source of low-carbon power. While this demonstrates nuclear’s potential to meet rising energy demand, high capital costs, long construction timelines, and ageing infrastructure constrain its near-term impact on decarbonization.
Accelerating the adoption of nuclear fission is essential for a low-carbon future. Targeted investment, commercial agreements, and technological innovation are critical to scale new reactor designs, improve efficiency, and ensure nuclear power can play a meaningful role in the Net Zero transition.
Startups have a key role in driving breakthroughs that reduce costs, streamline construction, and enhance safety, helping nuclear power complement renewables in meeting global climate goals. Strategic partnerships play an immensely important role in technology exchange and scaling to encourage adoption.
