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Science

How does a nuclear reactor work?

A nuclear reactor works by controlling a chain reaction of splitting atoms (fission) to release heat. That heat boils water into steam, which spins a turbine to generate electricity — much like a conventional power plant, but fueled by atoms instead of coal or gas.

See it in motion.
Watch a 2-minute animated lesson that shows exactly how a nuclear reactor works.
▶ Watch the visual lesson

Step by step

  • 1Splitting uranium atoms (fission) releases large amounts of heat.
  • 2Control rods absorb neutrons to keep the reaction steady and safe.
  • 3The heat boils water into steam that spins a turbine and generator.
  • 4It produces low-carbon power but creates radioactive waste.

Frequently asked questions

How does a nuclear reactor make electricity?
Fission heat boils water into steam, which spins a turbine connected to a generator.
What do control rods do?
They absorb neutrons to slow or speed the chain reaction, keeping it controlled and safe.
What is nuclear waste?
Leftover radioactive material from fission that must be safely stored for a long time.

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