They were aware the site was at risk of strike prior to it happening.

1 - they moved uranium off site (or may do that regularly as standard practice).

2 - centrifuges were likely moved off site just to prior to the strike.

The whole facility looks to only take a small area, around the size of a basketball court, so have no doubt this will be able to set up in another small area. Possibly multiple decentralised areas after this attack.