Tehran has said it for more than twenty years. The uranium is peaceful. The program is civilian. The enrichment is for energy. The line has survived presidents, wars, and two supreme leaders, repeated so often it has become the regime’s reflex.

It is worth taking the claim seriously for a moment. Seriously enough to follow the material from the ground to the centrifuge, and ask what each step is actually for.

The rock anyone can hold

Uranium is not exotic. It sits in the earth’s crust like any ore, mined underground, in open pits, or dissolved in place and pumped to the surface. The rock is crushed, milled, and concentrated into a yellow powder called uranium oxide, the form in which uranium is bought and sold. Nothing here threatens anyone. The raw material was never the problem. Possessing uranium is not the dangerous part. What you do to it is.

The needle inside the haystack

Natural uranium is almost entirely the wrong kind. About 99.3 percent of it is uranium-238. Only 0.7 percent is uranium-235, the isotope that splits easily and releases energy in a reactor. The two are nearly identical twins. Same element, same chemistry. They differ only by three neutrons of mass.

That tiny difference is the whole story. You cannot separate them with a chemical reaction, because chemically they are the same substance. You have to sort them by weight, atom by atom. This is why enrichment is hard, and why so few nations can do it.

The trick is to turn the uranium into a gas, uranium hexafluoride, and spin it at enormous speed........

© The Times of Israel (Blogs)