"Unprecedented": IAEA head on the current threat of nuclear catastrophe in Ukraine - 60 Minutes - CBS News

Europe's biggest nuclear power plant, Zaporizhzhia, is maybe the most dangerous place in the world right now.

"The whole system is being cooled by electricity that's coming in from the town, and there's shelling," Stahl said to Grossi.

"And you don't want the biggest nuclear power plant in Europe, one of the biggest in the world, to be cooled with-- basically an emergency system which is dependent on fuel.

"Until we have this plant protected, the possibility of the nuclear catastrophe is there.".

"When you went to visit, to inspect," Stahl asked Grossi, "you could go anywhere?".

"Well, there are reports that you weren't allowed into some crisis room there into the control room," Stahl said.

"You didn't want to see the control room?" Stahl asked.

"So this is where the external power comes to cool the reactors down," Grossi said.

"They were trying to cut off the power source," Stahl said.

"When you're operating at a nuclear power plant and you're under stress, and you're worried, and you're feeling threatened," Stahl asked Grossi, "doesn't that lead to the possibility of human error?"

"Would you say that [Putin] is familiar with what's going on," Stahl asked, "at this nuclear plant?"

Absolutely," Grossi said

"In my conversation with him, I could see that he had a very detailed knowledge, not only of the layout of the-- of the plant, but also, and very importantly, of the electrical access, the external power source," Grossi said

Putin trying to use this plant as a weapon?" Stahl asked

"Someone said to us the other day, 'You know, this is his dirty bomb, this plant.'"

"Yeah, but if you protect it there's no dirty bomb," Grossi said