Molten nuclear fuel in the No. 1 reactor at Japan’s Fukushima Daiichi plantburned through a steel pressure vessel and three-quarters of the surrounding concrete containment vessel, the reactor’s last substantial internal barrier, a report released by the plant’s operator and the Japanese government says...http://green.blogs.nytimes.com/2011/12/01/fukushima-meltdown-was-more-severe-than-thought-study-says/