Nuclear power

In this unit, we will learn about nuclear energy as a potential source of power. Nuclear energy is controversial because there are risks associated with nuclear power plants. Other sources of energy have risks as well. We will explore these.


As you read this introduction, think about two questions:

  1. How is nuclear energy similar to other sources of energy? How is it different?

  2. What are the advantages of nuclear power especially compared to the risks of other sources of energy?

Watch this video about how a nuclear reactor works

Steps of the process

A nuclear power plant consists of more than just the reactor "core" where the fission takes place. Look at the figure here and all the different steps of generating energy from nuclear reactors.

Here are a few notable steps:

  1. Neutrons are fired at radioactive isotopes, causing fission (splitting) of atoms into lighter elements that are also radioactive.

  2. Neutrons continue to fly through the reactor and strike other atoms ("going critical")

  3. Energy in the form of heat is released by fission which is used to boil water

  4. Steam from the water turns a turbine that converts the mechanical energy to electricity through a generator

  5. The water must then be cooled before it is heated again to maintain an optimal temperature for the reactor.

Image credit:

What happens to the radioactive waste?

Nuclear power is based on fission (splitting of atoms) not fusion (the combining of atoms). When uranium-235 (a radioactive isotope) is used in fission, the resulting products are other radioactive elements (for example, Barium).

All nuclear power results in radioactive nuclear waste that must be safely stored.

Depending on the element, nuclear waste remains radioactive for a few days or for thousands of years. Next, we'll read about the potential danger of radioactive exposure to human health and the environment. Nuclear waste storage is an important area of research as engineers and scientists try to keep the waste products from accidentally being released into the environment. All nuclear power generation carries a risk of a leak or failure of the system.

Comprehension Check

Review the video again if you are not sure about your answers:

  1. What is used to break an atom apart in nuclear fission?

a. Electron

b. Neutron

c. Proton

d. Boson

2. When an atom splits, what is released?

3. Why do nuclear reactors need to have their temperature regulated?

4. What is type of material is usually found in a nuclear reactor?

a. Uranium

b. Plutonium

c. Helium

d. Hydrogen

Check your answers.

Explore more