The calculations for it are a little weird and involve a rather strange unit called the SWU (separative work unit) and which is actually independent of the sepa

The calculations for it are a little weird and involve a rather strange unit called the SWU (separative work unit) and which is actually independent of the separation process, but it works out to be more like ~75% of the effort to go from natural -> 20% enriched as it is to go from 20% -> 95%. You still need the raw mass though. To get enough weapons-grade uranium for a bomb (~15kg) from 20% enriched feed stock and discharging 2% enriched depleted uranium waste you need about 65kg of 20% enriched. So 10kg (assuming it's 20%) is definitely concerning, but it's not enough to make a bomb.