On June 6, Japan’s Nuclear Emergency Response Headquarters confirmed that Japan’s Fukushima Daiichi nuclear power plant experienced full meltdowns at three reactors after the earthquake and tsunami on March 11, 2011, according to a CNN report.

Watch this CNN video interview with Michio Kaku, professor of theoretical physics at CUNY. In it, Kaku explains why the sudden influx of seawater into the plants prevented an explosion he describes as “3 Chernobyls.”