Sharply elevated radiation at the Fukushima Dai-ichi nuclear complex on March 27 forced an emergency evacuation of of the Number 2 unit. The concerns began when a worker attempting to measure radiation levels of water puddles there saw the reading on his dosimeter jump beyond 1 sievert per hour, the highest reading. Michiaki Furukawa, a nuclear chemist and board member of the Citizens’ Nuclear Information Center, a Tokyo watchdog group, said exposure to 1 sievert of radiation would induce nausea and vomiting, while levels between 3 to 5 sieverts an hour could be lethal. Yukio Edano, the Japanese government’s top spokesman, told a press briefing that it appeared the radioactive puddles had developed when the No. 2 unit’s fuel rods were exposed to air but that "we don’t at this time believe they are melting. We’re confident that we are able to keep them cool." (NYT, March 28)

There was the usual confusion and changing stories about the incident. Authorities initially reported that radiation readings spiked at 10 million times normal levels. Hours later, officials said this figure had been a mistake. But they then admitted that radiation in contaminated water was 100,000 times higher than than normal. (The Mirror, March 28)

Highly radioactive iodine seeping from Fukushima may be making its way into seawater farther north of the plant than previously thought, officials admitted. New readings March 28 show contamination in the ocean has spread about a mile (1.6 kilometers) farther north of the nuclear site than before. Radioactive iodine-131 was discovered just offshore from units 5 and 6 at a level 1,150 times higher than normal, Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, told reporters. Closer to the plant, radioactivity in seawater tested about 1,250 times higher than normal last week and climbed to 1,850 times normal over the weekend. (AP, March 28)

See our last post on the Fukushima disaster.

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