A powerful but double-edged source
Nuclear energy can supply enormous amounts of power, but using it brings both benefits and serious risks. A responsible country weighs both sides before deciding whether to build a nuclear power station.
Advantages
- High energy output — a small mass of fuel produces a huge amount of electricity.
- Low carbon emissions — a reactor produces almost no carbon dioxide, so it does not add greatly to global warming during operation.
- Reliable supply — a plant can run steadily day and night, unlike solar or wind which depend on the weather.
- Saves fossil fuels — reduces the need to burn coal, oil and gas.
Disadvantages
- Radioactive waste — spent fuel stays dangerously radioactive for thousands of years and must be stored safely.
- Risk of accidents — a serious failure can release radiation over a wide area, as at Chernobyl (1986) and Fukushima (2011).
- High cost — reactors are very expensive to build and to shut down safely.
- Weapons concern — the same materials can be misused to make nuclear weapons.
Example
After the 2011 tsunami, cooling failed at the Fukushima plant in Japan and radiation escaped, forcing thousands of people to leave their homes. This shows why safety systems must be very strong.
To manage these risks, radioactive waste is sealed in strong containers and buried deep underground where it cannot reach people or water. Modern reactors are also built with several layers of safety and thick shielding. Even so, no system is perfect, so a country must compare the steady, low-carbon electricity it would gain against the cost, the waste and the small chance of a serious accident before it decides.
Key idea
Nuclear energy offers high, low-carbon, reliable power, but carries the risks of radioactive waste, costly plants and rare but serious accidents.
Remember
The main long-term problem is safe disposal of radioactive waste, which stays harmful for a very long time.