Nuclear Fission

Updated: Jan 18

What is nuclear fission?

Nuclear Fission is the splitting of a large nucleus creating two new nuclei, a couple of neutrons and the release of a great amount of energy as part of the process. A nucleus is the central, dense part of an atom with the word being derived from the Latin word for the seed inside a fruit.

-  Nuclear Fission is the splitting of an atom resulting in the release of loads of energy.
-  The fission process results in further fissions creating a chain reaction which creates a million times more energy than using coal for power or TNT for a bomb.
-  Otto Hahn was credited with a Nobel Prize in 1944 for discovering nuclear fission. However, it is much debated that this should have been shared with Lise Meitner.
-  Nuclear Fusion provides the opportunity for cheap, clean energy but current remains in development. 

Nuclear Fission Explained

How does nuclear fission work?

Nuclear fission causes a heavy nucleus to decompose into two nuclei when bombarded by neutrons. This results in two equal size nuclei, a couple of neutrons and a large disengagement of energy. This process continues to repeat and creates what is known as a chain reaction.

A chain reaction is where the neutrons released by nuclear fission interact with other nuclei creating new fissions releasing more energy and more neutrons which will interact with more nuclei creating more energy and more neutrons as so on and so forth. The release of energy as part of nuclear fission is over a million times more than burning coal for energy or using TNT for a bomb.

Nuclear fission is used in nuclear bombs and for nuclear energy. It is easy to understand how the chain reaction described above results in the devastating energy release of an atomic bomb. However, as part of nuclear energy production, the rate of subsequent fissions is controlled ensuring a constant reaction within the nuclear reactor.

Who discovered nuclear fission?

Over the years preceding the discovery of nuclear fission there have been numerous contributions from the biggest names in the nuclear industry including Rutherford, Curie and Chadwick. However, there has been some controversy over the identification of who actually discovered nuclear fission.

There is no debate that nuclear fission was first achieved in Berlin in 1938 by a team of scientist lead by German chemist Otto Hahn. However, it was with the work of his colleague Fritz Strassman that Hahn found that uranium atoms could be split when bombarded with neutrons but neither could explain how the subatomic particles could make this happen.

It was in fact Lise Meitner, a Physicist based in Sweden, who had previously worked with Strassman that worked out how nuclear fission worked. In fact, she was actually the one that gave the process its name. However, in 1944 Hahn alone was awarded the Nobel Peace Prize for the discovery.

What is the difference between nuclear fission and nuclear fusion?

Nuclear Fission and Nuclear Fusion are both physical processed that produce energy from atoms. As described above Nuclear Fission involves the splitting of a heavy atom whereas Nuclear Fusion involves the joining (or fusing) of lighter atoms. Both have a huge release of energy as a by-product.

The main difference between Nuclear Fission and Nuclear Fusion are the fuel types, by-products, amount of energy released and technology availability.

Nuclear Fission uses Uranium or Plutonium with a release of energy 1 million times that of other sources. This dense energy source leads to much less fuel usage but the process does result in used nuclear fuel which needs to be stored and managed for many years.

Nuclear Fusion uses Hydrogen, the process results in only Helium as a by-product and the energy release is 3-4 times that of nuclear fission. However, although there are many nuclear fusion power plants in development there are not any currently ready to support the energy needs of the world.

Back to Nuclear Definitions