re: Observations
Well, as Holmes says, it's a mistake to theorize in advance of data, but it is fun.
Main thing is that, given only this information, I can see options other than "reactor," although "reactor" fills the bill, too.
I'm assuming Israel, and the U.S., have somewhat more detailed photos and information. According to the story, Israel actually penetrated the site and brought back samples.
Of course, this is all assuming that this is even the site that got attacked, isn't it?