Large facilities such as Iran’s Natanz, where large numbers of centrifuges are kept, will be easier to monitor. But small, clandestine sites can be dismantled in 24 days.
“Much of this equipment is very easy to move,” Heinonen said. “So you can take it out over the night … and then there is this dispute settlement time which is 24 days—you will use that to sanitize the place, make new floors, new tiles on the wall, paint the ceiling and take out the ventilation.”

A large-scale enrichment plant would not be easily scrubbed in 24 days, but smaller covert facilities that are used toward the end of the nuclear weapons process can be hidden or sanitized in 24 days, he said.

“You can compare it to your home,” Heinonen said. “This [nuclear] equipment can be taken out in one or two nights. How long will it take for you to renovate your home? It doesn’t take three weeks.”

A case in point involved two suspect Iranian nuclear facilities in 2003.