We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Fast Breeder Reactor?

By Christian Petersen
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A fast breeder reactor is a type of nuclear reactor that uses nuclear fission to create plutonium 239 atoms as a by-product of the splitting of uranium 235 atoms. This process creates more fuel in the form of plutonium 239 than it uses. This ability to create, or "breed," additional fuel accounts for the name given to these types of reactors. A fast breeder reactor can create up to 30% more fuel than it consumes.

Nuclear reactors produce energy by splitting the atoms of fissile fuels, usually uranium 235. This also produces free neutrons, particles from the nucleus of atoms, which then strike other uranium atoms, splitting them and furthering the fission reaction. In standard nuclear reactors, most of these neutrons are kept at a low energy level by an advanced cooling system that normally uses water as a medium. This is done to keep the neutrons at an energy level suitable for sustaining the fission reaction.

In a fast breeder reactor, the cooling system is deliberately less efficient and is usually filled with liquid sodium. This keeps the neutrons that are produced by the fission reaction at a higher energy level. These "fast" neutrons provide the other part of the common name of a fast breeder reactor. High-energy neutrons are less suited for splitting other uranium 235 atoms but do serve another purpose.

Instead of splitting uranium 235 atoms, the "fast" neutrons are absorbed by uranium 238 atoms, which makes up most of the mass of nuclear reactor fuel in a fast breeder reactor. Uranium 238 is not suitable for fission, but after absorbing another neutron, uranium 238 is converted to plutonium 239. Plutonium 239 is very suitable as a nuclear fuel and can be used for making nuclear weapons. Some plutonium 239 atoms decay into another isotope of uranium, uranium 239 which is also used as a fuel in nuclear reactors.

Plutonium is often used for nuclear weapons. For this reason, many fast breeder reactors that once were operational have been shut down. Other problems with these types of reactors have contributed to their decline in popularity amongst nations with nuclear power programs. The plutonium 239 must be extracted from the other components of nuclear fuel and this is a complex and expensive process. It also can be extremely dangerous and creates toxic radioactive waste as a by-product.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.