Whatever it is, it has been grabbing attention recently. It is interesting to see that the same is being reported elsewhere, especially in a country even more tight lipped about its activities.

Obviously even top secret clearance has a lot of layers within it. I don't just mean the usual seniority levels one would expect, but the fact that any top secret project needs human guards/security personnel, receptionists, cleaners, drivers/manual workers and so on, who are not neither scientists nor military personnel in any classic sense. There would have to be a number of those. Heck, even the people who restock coffee machines or work in cafeterias would need a security check.