How Nuclear Energy Works

What is nuclear energy?

Nuclear energy provides efficient and reliable electricity around the world. Today, more than 400 commercial reactors operate in more than 30 countries.

The common definition for nuclear energy is the energy released by a chain reaction, especially by fission or fusion. Practically speaking, nuclear energy uses fuel made from mined and processed uranium to make steam and generate electricity.

Nuclear generation is the only source of electricity that can produce a constant supply of power – known as baseload power—reliably without emitting greenhouse gases.

Nuclear energy has one of the lowest environmental impacts on land and natural resources of any electricity source.

Nuclear Energy in the UAE

In the UAE, the Barakah Nuclear Energy Plant, located in the Al Dhafra Region of the Emirate of Abu Dhabi, is home to four reactors. Each reactor is designed to produce 1,400 megawatts (MW) of electricity with nearly zero carbon emissions.

Built to operate for 60 years or more, these reactors will provide efficient and reliable low-carbon electricity to the nation for generations to come. Once fully operational, the plant will prevent the release of more than 21 million tonnes of greenhouse gas emissions per year. This is equivalent to removing 3.2 million sedan cars from the UAE’s roads.

In 2016, ENEC established Nawah Energy Company, which is responsible for operating and maintaining the four reactors at Barakah. As the teams at both ENEC and Nawah prepare for the plant to transition from a construction project to an operating facility, they work to ensure that it meets the highest national and international standards of quality, and benefit from global operating experience.

How does it work?

A nuclear reactor produces electricity in much the same way other power plants do. The chain reaction produces the energy, which turns water into steam. The pressure of the steam turns a generator, which produces electricity.

The difference is in how the heat is created. Power plants that run on fossil fuels burn coal, oil or natural gas to generate heat. In a nuclear energy plant, heat is produced from splitting atoms – a process called nuclear fission.

  • Nuclear reactor creates heat that is used to make steam
  • The steam turns a turbine connected to an electromagnet, called a generator
  • The generator produces electricity

In a Pressurized Water Reactor (PWR) – the type of reactor being built in the UAE – high pressure prevents water in the reactor vessel from boiling. The super-heated water is carried to a steam generator, which is made up of many small pipes. The heat in these pipes is used to turn a second, isolated, supply of water to steam, which is in turn used to drive the turbine. The water from the reactor is pumped back into the reactor vessel and reheated. The steam from the turbine is cooled in a condenser and the resulting water is sent back to the steam generator.


Enriched uranium is the fuel for nuclear reactors. Uranium is an abundant, naturally radioactive element found in most rocks. As uranium breaks down or decays, it produces heat inside the Earth’s crust. A similar process generates heat inside a nuclear reactor.

Nuclear Fission

Fission is the process of splitting a nucleus in two.

Inside each uranium fuel pellet, there are millions of uranium nuclei. When these nuclei are split, a huge amount of energy is released. Some of this energy is from radiation, but the biggest source is kinetic energy. This is the energy that produces heat inside a reactor, which in turn is used to generate steam, and ultimately creates electricity.

Worldwide facts

For more than 60 years, nuclear energy has provided the world with reliable electricity.  Today, more than 400 reactors are operating in more than 30 countries. 

These plants generate around 10 percent of the world’s electricity without emitting greenhouse gases.

More nations are exploring the use of nuclear energy, particularly as electricity demand increases and concerns about climate change rise.


For more information, visit the following online resources:

International Atomic Energy Agency

World Nuclear Association (WNA)

World Association of Nuclear Operators

Nuclear Energy Institute (NEI)

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