Thorium-232, the only naturally occurring isotope of thorium, is a fissionable material but not a fissile one, meaning that it needs high-energy neutrons to undergo fission — the splitting of atomic ...

As a handful of neutrons travel through a reactor pile or other fissionable material, a couple of outcomes are possible. Any one neutron collision might result in fission. This means there will be ...

A breeder reactor, like the one scientists in Idaho were trying to build, converts uranium-238’s “nonfissionable material into fissionable material more rapidly than the nuclear fuel is ...

An Ann Arbor engineering company is working on a device to scan for smuggled "fissionable materials" at border checkpoints and is getting a $750,000 government contract for the project.

It requires solving several very difficult problems simultaneously. Acquiring the fissionable material to generate a nuclear explosion is the single most difficult step. But other daunting ...