Science
How does nuclear fission work?
Nuclear fission works by splitting a heavy atom's nucleus, like uranium, into smaller pieces. This releases a huge amount of energy plus neutrons that split more atoms — a chain reaction. Power plants control this to make heat, which generates electricity.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how nuclear fission works.
Step by step
- 1A heavy nucleus (like uranium) is split apart.
- 2Splitting releases large energy and free neutrons.
- 3Those neutrons split more atoms — a chain reaction.
- 4Reactors control it to produce heat and electricity.
Frequently asked questions
- How does nuclear fission work?
- Splitting a heavy atom's nucleus releases energy and neutrons that split more atoms in a chain reaction.
- What's the difference between fission and fusion?
- Fission splits heavy atoms apart; fusion joins light atoms together, as in the Sun.
- How do reactors stay safe?
- They use control rods and coolant to regulate the chain reaction and prevent it from running away.