Nuclear security

How South Africa Built Nuclear Weapons (And Then Gave Them Up)

Acquiring fissile material is half the nuclear secret. The other half of the secret is that nuclear weapons actually work. (The United States spent the money and manpower to get the first and prove the second. Other powers just need the first.) Separating the minute amounts of fissile Uranium 235 from Uranium 238 is a key step in fissile material production. Uranium can be combined with fluorine to create the chemical uranium hexafluoride, a toxic, corrosive, heavy gas. This gas can be forced through a very long series of filters or sieves that separate the lighter U-235 from the heavier U-238. Diffusion plants are the size of auto factories and consume more electricity—they’re hard to hide.