Steam rises from the Fukushima #3 nuclear reactor, March 19, 2011. (Photo: daveeza) On April 12, 2011 the Japanese government officially announced that the severity of the Fukushima Daiichi nuclear disaster had reached level 7, the highest on the International Nuclear Event Scale. Before Fukushima, the only level 7 case was the 1986 Chernobyl disaster, whose 25th anniversary was marked on ...