Nuclear fission, discovered in 1938, involves splitting an atom’s nucleus, releasing energy. It’s essential for electricity generation in nuclear power plants and occurs naturally through radioactive decay.
Nuclear fission is the process where the nucleus of an atom splits into two or more smaller nuclei, along with other particles. These particles can include neutrons, alpha particles (helium nuclei), beta particles (electrons), and gamma rays (which are particles of light, or photons). Fission was discovered in 1938 by Otto Hahn, Lise Meitner, and Fritz Strassmann by bombarding elements with neutrons.
Fission Reactions and Energy Production
Fission can be triggered when the nucleus of a material is bombarded by particles such as neutrons and protons. This type of fission, known as a nuclear reaction, releases significant amounts of heat and radiation. Modern nuclear power plants harness this heat to boil water, driving steam turbines that generate electricity.
Scientists use the term fission cross-section to describe the likelihood that fission will occur. Fission cross-section depends on the energy of the incoming particle and the material of the nuclei that are being hit.
Spontaneous Fission and Natural Decay
Fission can also be spontaneous and occur naturally. This is the process where radioactive elements decay into lighter elements. Some materials are naturally unstable and use radioactive decay to reach a more stable state. This is how some smoke detectors work in your home—they use the electrical current made possible by particles from radioactive decay. If particles of smoke disrupt the current, the alarm goes off.
Fission Facts
- The National Nuclear Data Center at Brookhaven National Laboratory maintains databases for nuclear properties for the entire periodic table.
- Nuclear reactors can use the fission of uranium for fuel. A uranium fuel pellet the size of an egg has as much energy as 88 tons of coal.
- Learn more about how fission makes smoke detectors work.
DOE Office of Science: Contributions to Nuclear Fission Research
The Department of Energy (DOE) Office of Science, Office of Nuclear Physics supports research to understand all forms of nuclear matter. Fission processes are used by researchers in basic science, medicine, non-proliferation/defense, and energy to advance our knowledge and technology. These experiments use equipment at DOE Office of Science user facilities such as the Facility for Rare Isotope Beams at Michigan State University and the Argonne Tandem Linac Accelerator System
at Argonne National Laboratory. Experiments collect new data on fission processes and examine properties on new materials. Theorists use new and updated data to improve predictions for modeling and simulation.