Today’s Wonder of the Day was inspired by Cami. Cami Wonders, “What is nuclear energy?” Thanks for WONDERing with us, Cami!

How many electronics do you use every day? Really think about it. Do you spend time on a smartphone? How about a computer? Do you watch TV? Maybe you play video games after school. These devices give people many hours of entertainment every day.

You can’t have electronics without one thing: electricity! Where does this power source come from? In many areas, people make it by burning fossil fuels. These produce greenhouse gases. The Earth will also run out of them one day. For these reasons, scientists have been looking for other energy sources for many years.

You might already know about solar and wind power. These are two alternative energy sources. Another one has also become popular in many areas of the world. It doesn’t produce greenhouse gases, but it does create hazardous waste. It’s connected to disasters in places like Fukushima, Chernobyl, and Three Mile Island. What are we talking about? Nuclear energy, of course!

How do nuclear power plants work? They have a lot in common with those that burn fossil-fuels. Both heat water to turn it into steam. Both use that steam to turn a turbine generator that makes electricity. Instead of burning fossil fuels to make heat, though, nuclear reactors rely on another process. It’s called nuclear fission.

How does nuclear fission happen? First, neutrons are fired at the nucleus of a radioactive element called Uranium-235 (U-235). The U-235 nucleus absorbs these neutrons. This causes it to become unstable. It splits, releasing energy. This makes a great deal of heat.

A little bit of U-235 can go a long way. As an example, let’s consider a submarine that runs on nuclear power. One pound of highly-enriched U-235 as fuel would be equal to about a million gallons of gasoline! That’s why many people want to use Uranium instead of fossil fuels.

Others worry about the dangers of nuclear energy. Radioactive materials are used in nuclear power plants. Special safety precautions have to be taken. These keep the workers and those who live near the power plant safe. 

The nuclear energy industry has learned lessons from disasters in plants like Chernobyl. Today, nuclear reactors are usually housed in steel vessels. These are then surrounded by multiple solid concrete barriers. This could contain much of the radiation in case of a meltdown. 

Still, meltdowns aren’t the only concern. Nuclear power plants also produce high-level radioactive waste. It takes tens of thousands of years for this material to decay to safe levels. That’s why it must be carefully stored and monitored in large concrete structures.

Despite its risks, nuclear energy has many positives. These make it an attractive alternative to fossil fuels. For example, it makes about a million times more energy per unit weight than fossil fuels. Nuclear power plants also put very little carbon dioxide in the air. 

Today, there are over 400 nuclear power reactors around the world. Some countries, such as France and Lithuania, produce more than 75% of their power using nuclear power plants. In the United States, over 100 nuclear power plants create nearly 20% of the country’s energy.

What do you think? Is nuclear power the clean energy solution the world needs? Or is the risk of disaster too great? What other types of energy do you think the world should try?


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