nuclear fission

[noo-klee-er fish-uhn]

noun

1. fission.

nuclear fission

noun

1. Sometimes shortened to: fission. the splitting of an atomic nucleus into approximately equal parts, either spontaneously or as a result of the impact of a particle usually with an associated release of energy Compare nuclear fusion

fission, nuclear

1. A nuclear reaction in which a single large nucleus splits into two or more smaller nuclei. In some cases, for example with uranium, energy is released in this process.

Pronunciation Note

See nuclear ( def. ).

The fission of uranium 235, an isotope of uranium, supplies energy for nuclear reactors and atomic bombs (see also atomic bomb).

Word History and Origins

Origin of fission, nuclear¹

First recorded in 1885–90

Example Sentences

It is produced by nuclear fission for use in medical gauges and devices, but can also be a byproduct of nuclear reactors and weapons testing, the agency said.

From Los Angeles Times

Like all nuclear fission plants, they are controversial.

From BBC

It will contain radioactive uranium split by nuclear fission, in a chain reaction which generates a lot of heat.

From BBC

Left untouched, nuclear fission erupts into a runaway chain reaction that can heat the core of a nuclear plant to thousands of degrees, liquifying the metal around it into radioactive lava.

From Los Angeles Times

Because the process of nuclear fission does not burn or oxidize anything, nearly all the fuel used in producing energy at nuclear plants becomes waste without reducing its mass.

From Salon