Radioactive cesium fallout around the Fukushima Dai-ichi nuclear plant, 8 March 2012 - 16 March 2012. Levels rose more than five times in Fukushima over a 24-hour period between March 15 and 16. Posted by Mochizuki on 18 March 2012. TEPCO via fukushima-diary.com

By Charlie Smith
19 March 2012 A Japanese citizen watchdog has reported that cesium-137 levels rose more than five times in Fukushima over a 24-hour period between March 15 and 16. The online Fukushima Diary pointed out that there were no megabecquerels per square kilometre of cesium-137 detected between March 8 and March 11. But it rose to 17.8 MBq per kilometre from March 11 to March 12. The following day, it reached 25.1, before rising to 128 on the next day. The Fukushima Diary—which carries the statement “We are against media blackout”—said there was no explanation for the sudden increase from the Tokyo Electric Power Company, which owns the nuclear-power plant in Fukushima. […] Levels of cesium-134, which has a half-life of just over two years, also shot up over the same period. It went from from zero MBq per kilometre on March 10 to 88.6 MBq per kilometre between March 15 and March 16, according to the Fukushima Diary. In November, it reported that cesium-134 and cesium-137 releases from Fukushima were already at 95 percent of what was discharged from the Chernobyl nuclear reactor when it exploded in Ukraine in 1986.

Radioactive cesium levels rise sharply in Fukushima, according to citizen watchdog