Nuclear is probably the most controversial of all energy sources. Denounced by some for the radioactive waste it generates and the risks of nuclear accidents, others claim that it plays an essential role in energy transition.

According to the latest forecasts by the International Energy Agency, the world's nuclear energy production will increase by 15% by 2030. However, it will figure less prominently in countries' energy mix.

Each country has its own policy: the possible scenarios

Total nuclear phase-out

• Germany, Belgium and Switzerland are planning a total phase-out of nuclear power.
• Other countries have been abandoning nuclear power for many years. This is the case, for example, in Italy and Austria.

The return of nuclear power

Conversely, some countries have decided to invest in the revival of nuclear power:

• the United Kingdom, Poland and Hungary, for example, consider nuclear power to be essential to achieve the planned reductions in CO₂ emissions and to ensure their security of supply.
• the Netherlands have launched a study for the construction of new nuclear power plants from 2025 onwards.
• China is investing heavily in nuclear power. It has increased the number of plants in operation by a factor of 10 compared to the year 2000.

A wait-and-see attitude

In between these approaches, some countries have not yet clearly decided on their nuclear policy.

In France, the share of nuclear power in the energy mix is to be reduced to 50% by 2035. However, two scenarios are being weighed up for the future:

• a gradual reduction in the share of nuclear power as plants naturally close at the end of their service life
• or maintaining this share at 50%. This second option would require the construction of 6 new nuclear reactors.

Over the past 50 years, the United States has also invested little in nuclear power. But this could change, as the Democrats have said they are in favour of investing in small modular reactors (small, medium-power nuclear reactors) to deal with the climate emergency.

What are the advantages of nuclear energy for the energy transition?

No greenhouse gas emissions

The big advantage of nuclear power is that it does not emit greenhouse gases. For its advocates, nuclear power is essential to keep global warming below 2°C by limiting greenhouse gas emissions.

Useful to manage the power grid balance

Unlike renewable energies, the production of nuclear energy does not depend on climatic conditions.

When wind turbines do not turn and solar panels do not produce enough electricity, it can take over to ensure that enough electricity is produced to meet the needs of consumers and in turn contribute to the balance of the power grid.

What developments are there for nuclear generation? 

Although nuclear energy is not set to disappear overnight, this does not mean that the technology used will remain the same as that used until today. Several innovations are currently being explored and researched.

Small Modular Reactors: more flexible

These 'mini-reactors' are small modules with a capacity of 10 MW to 300 MW (compared to 500 MW to over 1650 MW for a conventional nuclear reactor), and can provide the electricity needed for industrial sites or remote areas.

Flexible and self-contained, SMRs can easily meet fluctuating energy demands and are likely be used to top up the production of conventional nuclear reactors.

Fast neutron reactors

These 4th generation reactors (unlike the 3rd generation reactors currently in service) could operate with uranium-238, which constitutes 99.3% of natural uranium, rather than uranium-235 (0.7% of natural uranium).

• They would therefore make it more profitable to extract uranium from the subsoil.
• In addition, they could potentially burn plutonium and turn long-lived nuclear waste into short-lived nuclear waste.

Several tests are underway, notably in France, where sodium-cooled fast neutron reactors are being tested.

Thorium reactors

More abundant than uranium, almost 100% of thorium-232 can also be used as a fuel. That is why research is underway to use this fuel to power nuclear reactors.

Molten salt reactors

In these reactors, the fuel is in liquid form, dissolved in molten salt.

• This system allows for increased efficiency and less waste.
• Because they operate at low pressure, the risk of coolant ruptures and leaks in the event of an accident is reduced, thereby improving reactor safety.

Nuclear fusion

While nuclear fission is about breaking an atomic nucleus to release energy, nuclear fusion is about fusing light atomic atoms together. This phenomenon, which occurs naturally in the core of stars like the sun and releases enormous amounts of energy, is very complicated to reproduce.

To date, nuclear fusion remains experimental and only a few Chinese or international research reactors are currently able to operate for a few seconds.