How does nuclear power work?

Nuclear power is a way of making electricity using energy from the center, or nucleus, of atoms.

This energy is released inside nuclear power plants through a controlled process that produces heat, which is then used to generate electricity.

How is the energy released?

Most nuclear power plants use a process called fission, which means splitting atoms. The fuel for this process is usually uranium-235, a special type of uranium that can easily split, says the IAEA.

When a tiny particle called a neutron hits a uranium-235 atom, the atom splits into smaller parts. This releases a large amount of heat and radiation. It also releases more neutrons.

These new neutrons go on to hit other uranium atoms, causing them to split as well. This repeating process is called a chain reaction. In a nuclear reactor, this chain reaction is carefully controlled so it does not happen too fast.

How is heat turned into electricity?

The heat from fission is used to warm water. This creates steam, which is the key to producing electricity.

There are two main types of nuclear reactors:

• Boiling Water Reactors (BWR): Water inside the reactor is heated until it boils directly into steam.
• Pressurized Water Reactors (PWR): Water is kept under very high pressure so it does not boil. Instead, it transfers heat to a separate system where steam is produced.

Once steam is created, it spins a turbine. A turbine works like a windmill, but it is powered by steam instead of wind.

The turbine is connected to a generator. Inside the generator, moving magnets help produce electricity. This electricity is then sent to homes and businesses.

After passing through the turbine, the steam is cooled back into water in a condenser. The water is then reused, and the cycle starts again.

What about the fuel?

Uranium used in reactors must first be processed in a step called enrichment. Natural uranium contains very little uranium-235, so enrichment increases the amount to make it usable as fuel.

This fuel can be used in a reactor for about three to five years. After that, it becomes "spent" fuel and must be safely stored or recycled.

How does nuclear power affect the environment?

Nuclear power is considered a low-carbon energy source because it produces almost no carbon dioxide during operation. It currently provides about 9% of the world's electricity.

However, it does produce radioactive waste. This waste must be handled and stored carefully because it remains dangerous for a long time.

What is the difference between fission and fusion?

Nuclear power today is based on fission, which splits atoms.

Another process, called fusion, works in the opposite way. It joins small atoms together to form a larger one, releasing energy in the process. Fusion has the potential to produce large amounts of energy, but it is still in the research stage and is not yet used for commercial electricity.

Nuclear power plants use controlled atomic reactions to produce heat, turn water into steam, spin turbines, and generate electricity. While the technology produces low carbon emissions, it also requires careful handling of radioactive materials and waste.