This seems backwards.
The tailings do not become nuclear waste when we decide to use them for something.
The tailings do not become nuclear waste when we decide to use them for something.
If you want an actual bomb, you need that U233 without any thorium, because the thorium mostly just turns to U233 when it absorbs a thermal neutron (i.e. slowed down by a moderator like graphite). In a bomb you're relying on fast neutrons.
Read enough books/articles on thorium reactors and you'll come across a photo of the US thorium stockpile, which is a great big stack of pure thorium bricks.