Where does excess uranium 238 goes?

Question

Natural uranium is 0.7% U-235 and the rest is U-238. For nuclear reactor you need enriched uranium with higher percentage of U-235. But what to do with U-238 if it’s useless as reactor fuel, as a nuclear weapon, and still radioactive to use it as regular material.

In: Physics

Answer 1

There are some limited uses, but most of it is simply stored as trash. Either directly as uranium hexafluoride, the chemical used for enrichment, or converted to solid uranium for safety.

Its radioactivity is very weak, its chemical toxicity is typically more important. In that sense a block of uranium (especially depleted uranium) it’s not significantly more dangerous than e.g. lead.