Why do we need nuclear energy?

Electricity generation accounts for over 40% of global energy-related emissions. Nuclear energy produces almost no direct greenhouse gas emissions and has lifecycle emissions (total greenhouse gas emissions across a technology's full life cycle, from construction to decommissioning) comparable to wind and far lower than solar.

Nuclear power plants are one of the largest sources of low-carbon electricity in the world, providing a continuous supply of energy that complements renewables and storage technologies. Including nuclear in the mix makes achieving deep decarbonization significantly easier and cheaper.

Fission Fact: Nuclear avoids around 2 billion tonnes of carbon dioxide emissions from equivalent coal generation annually — enough to offset the carbon footprint of the entire global aviation sector nearly twice over. 

Energy security means having uninterrupted access to energy, and predictable supply at an affordable price. Nuclear supports energy security by providing reliable baseload power and using fuel that is highly energy-dense and easy to transport and store.

A major risk to energy security is fuel disruption. Unlike gas or coal plants that depend on frequent deliveries, nuclear power plants can keep several years of fuel on site, making them less exposed to interruptions in supply chains. Uranium is also sourced from a range of countries, which reduces dependence on any single supplier. And because fuel is a relatively small share of nuclear operating costs, nuclear generation is less vulnerable to sudden fuel‑price shocks.

Fission Fact: A fingertip-sized pellet of uranium produces as much energy as almost three barrels of oil, more than 350 cubic metres of natural gas, and about half a tonne of coal. A 1 GWe power plant requires around 20-30 tonnes of fabricated nuclear fuel annually, compared with over three million tonnes of coal.

Today, coal is still the largest source of electricity, over one-third globally. This is due to its relative geographical abundance and ability to provide power on demand. Despite the rapid expansion of wind and solar, they remain weather-dependent and require backup generation, usually from gas.

Nuclear power plants are very reliable, and can run for many months without interruption, providing large amounts of clean electricity, regardless of the time of day, the weather, or the season.  

Fission Fact: The global nuclear reactor fleet ran at an average capacity factor of 83% in 2024, higher than any other source of electricity. This measure of reliability has been reflected consistently over the past 20 years, with performance remaining high regardless of the reactor age.  

Nuclear is efficient because a small amount of fuel produces a very large amount of electricity. This high energy density means nuclear power plants use relatively little land and require far less fuel to be mined, transported, and handled than most other sources. It also means the amount of spent fuel is small in volume, concentrated, and can be safely managed.

Like other thermal power plants, nuclear does require water for cooling. In most designs, the water is returned to the environment, with only a small temperature increase.

Fission Fact: The amount of land needed per kWe of installed capacity from nuclear is much less than from other sources of generation; for example, nuclear uses around 30 times less land than solar PV to produce the same amount of electricity.

Nuclear reactors produce large amounts of energy and can be built as a repeatable programme. Building multiple reactors to a standard design helps delivery improve over time: skills and supply chains scale up, lessons learned are carried from one unit to the next, and schedules become more predictable.

This approach has been proven before: after the oil shocks of the 1970s, several countries accelerated nuclear construction to strengthen energy security and reduce exposure to imported fuels. Today in the wake of further energy crises, many countries are recognizing the benefits of nuclear, planning new-build programmes and extending operating lifetimes. Life extensions are a cost-effective way to maintain capacity, but meeting future demand will require sustained new‑build programmes.

Fission Fact: France rapidly expanded its nuclear power programme after the 1974 oil crisis, and within about 15 years nuclear energy grew from a minor contributor to providing most of the country’s electricity. Today, over 70% of France’s electricity comes from nuclear power — the highest share of any country in the world.