Dr Bettina Wittneben , Lecturer in Management at Oxford's Saïd Business School and Associate Fellow at Pembroke College and the School of Geography and the Environment , sets out four risks that policymakers should weigh before committing to new nuclear capacity
The Fukushima nuclear disaster on 11 March 2011, triggered by a tsunami and leading to multiple reactor meltdowns, shook confidence in nuclear safety well beyond Japan. In Germany, it was a turning point : Chancellor Angela Merkel's government suspended nuclear power's earlier lifetime extensions and ultimately pursued a phase out, with broad parliamentary support.
Fast forward to today, and in parts of Europe, nuclear power is being re-cast as the answer to decarbonisation and energy insecurity, as highlighted by the Israel/US-Iran conflict. Some German politicians went so far as to call the country's decision to end nuclear power a mistake .
This is a useful reminder that nuclear policy is not only about engineering and economics; it is also about political legitimacy and how much risk the public is willing to accept .
But despite recent enthusiasm for nuclear power, a close examination shows that the risks of increasing nuclear capacity are high. Policy makers and the public need to consider four types of risk: climate, security, capacity and financial risks.
"In the high‑renewables systems of Europe, the problem is increasingly not how to generate more electricity but how to access it when and where it's needed."
Climate risk: Nuclear power plants are not climate resilient
As Europe experiences climate impacts such as heatwaves and drought, several nuclear power plants have had to be at least partially shut down to accommodate low water levels and risks to aquatic life in natural water systems. When a nuclear plant is shut down, it continues to draw on electricity generated elsewhere to avoid a meltdown.
Given that global heating is a reality today, nuclear power generation is no longer a viable long-term option in hotter temperatures and drier climates. In Britain, we have had to come to terms with the fact that an approaching wildfire could have catastrophic consequences for a nuclear power plant.
The strategic point for policymakers is straightforward: If the climate is changing how we operate existing plants, it should also shape the way we assess the benefits of new build.
Nuclear power is sometimes hailed as a climate mitigation instrument as it is low carbon at the point of generation. However, the bulky concrete structures mean that it has a large amount of embodied carbon and, of course, it is not a renewable energy as it requires the mining of uranium, bringing with it carbon costs in terms of extraction and transport. Nuclear waste disposal and decommissioning must also be factored into the carbon budget of nuclear energy generation.
Security risk: Nuclear power poses real security risks
As we have seen in Ukraine and now also in the UAE , nuclear power plants are favoured sites for drone and other attacks and can be the scene of intense battles. A small drone exploding on the radiation shield of the ill-fated Chernobyl nuclear reactor caused major global concern as repairs to this vital safety structure are risky, and the associated costs of maintaining safety are extremely high.
Capacity risk: Nuclear power contributes to grid overload during electricity generation peaks
For the past decade, energy experts have insisted that, as consumers of solar and wind-generated electricity, we need to be concerned about the times when the sun doesn't shine and the wind doesn't blow, referred to as Dunkelflaute (dunkel=dark, flaute=lull). How do we keep the lights on and the economy whirling away during these dark, windless times? This is also the narrative of fossil fuel advocates, who present fossil gas as the saviour of the baseload, or the electricity that is available when renewables fall short. Fossil fuel sceptics point instead to nuclear power as a reliable baseload technology.
Making decisions based on Dunkelflaute anxiety is no longer rational, however. With renewables rapidly expanding - driven by low prices and the need for energy independence - grids are facing the opposite problem: energy surplus. For example, in May 2025 Germany experienced negative electricity prices on 21 days of the month. These occurrences resulted from the Hellbrise (hell=bright, brise=breeze): a situation where wind and solar generated more electricity than national demand.
In many European countries national grids cannot cope with these peaks of production meaning that electricity is either wasted or diverted if it cannot be stored. Nuclear power plants, which are slow and costly to turn off, only amplify our grids' Hellbrise challenge.
Financial risk: Nuclear power generation remains very costly
Back in 2011, the Fukushima accident turned the public against nuclear power in Germany. Over the past decade, the nuclear industry has reeled from this. The solution from this industry is to build smaller, modular reactors, with the aim of diminishing risks and reducing costs via economies of scale.
Unfortunately, this reasoning is flawed. Nuclear waste is expensive to store safely , and engineers continue to struggle to identify long-term waste disposal sites.
Decommissioning costs must be factored into the financing of the power plant as it is highly expensive to dispose of the large concrete buildings and remaining radioactive materials. Otherwise, decommissioning and long-term waste storage falls to the taxpayer of the future.
In addition, there are other financial costs and risks : acts of war are still entirely possible and exceedingly dangerous; uranium mining commits providers to continued social and environmental impacts; renewables remain more competitive on cost.
Given the risks of nuclear power, there are better energy solutions
Nuclear power production does not help us cope with the challenge emerging from our power grids and the future of electricity production - the Hellbrise.
Instead, we should focus on improving flexibility of grids and energy demand, increasing energy efficiency, and addressing the technical challenges of energy storage. This strategy will more effectively support economies than nuclear power ever could.
