2011 Science News of the Year: Science & Society
By Science News
Following earthquake and tsunami, radiation is Japan’s true aftershock
The worst earthquake in Japan’s recorded history — and, at magnitude 9.0, one of the most powerful ever recorded — didn’t end when the shaking did on March 11. Within hours, a meters-high tsunami swamped much of the coastline, including the Fukushima Daiichi nuclear power station, setting off the worst nuclear accident since the 1986 Chernobyl meltdown in Ukraine (SN: 4/9/11, p. 5).
Three reactors at the Fukushima plant exploded, releasing radioactivity carried by winds across Japan and then around the globe (SN Online: 3/19/11). Radiation physicists continue to argue about how much radioactive material, such as cesium-137, escaped, with independent assessments often coming in much higher than the Japanese government’s official numbers. In late November the Tokyo Electric Power Co., which operates the plant, announced that at the worst-hit reactor, Unit 1, fuel rods had probably melted completely during the accident and pooled in the concrete bottom of the containment vessel.