Though global fears about radiation emissions from the heavily damaged Fukushima Daiichi nuclear power facility have calmed in the weeks since Japan's devastating March 11 earthquake and tsunami, famed physicist Michio Kaku insists the situation remains a "ticking time bomb."

A professor of theoretical physics at the City University of New York and the City College of New York, Kaku discussed some recent revelations about the disaster's impact, and noted that Japanese officials still don't have control at the site. "In the last two weeks, everything we knew about that accident has been turned upside down," Kaku says. "Now we know it was 100 percent core melt in all three reactors...now we know it was comparable to the radiation at Chernobyl."

Among Kaku's other distressing notes: Fukushima workers are exposed to a year's dose of radiation within minutes of entering the site, and cleanup will take between 50 to 100 years. "It's like hanging by your fingernails," he says. "It's stable, but you're hanging by your fingernails."

Watch Kaku's interview with CNN here: