Eli5, what does ‘enriched’ mean in the context of, for example, ‘enriched uranium’?

Question

Eli5, what does ‘enriched’ mean in the context of, for example, ‘enriched uranium’?

In: Physics

Answer 1

Natural Uranium is mostly U-238 isotopes (99%) that isn’t useful for Nuclear Reactors or Weapons. The Enrichment process helps separate the U-235 isotopes from U-238 to create higher concentration of U-235.

Low Enriched Uranium (LEU) has concentrations below 20%. Nuclear Reactors use LEU generally.

Highly Enriched Uranium has concentrations l 20% and above. Weapons use HEU, with typical weapons using 85-90% in their primary.

[Wiki: Enriched Uranium](https://en.wikipedia.org/wiki/Enriched_uranium)

The Isotope Separation can be done using a [Gaseous diffusion](https://en.wikipedia.org/wiki/Gaseous_diffusion)
or [Gas Centrifuge](https://en.wikipedia.org/wiki/Gas_centrifuge) method. The latter becoming more economical and beneficial with improvements over time.