March 16,20111750.
1.58pm: James Randerson has sent through some more interesting nuclear context, from the UK’s Institution of Mechanical Engineers. He particularly highlights this snippet:
A concern for the people not just of Japan but the Pan Pacific area is whether Fukushima will turn into the next Chernobyl with radiation spread over a big area. The answer is that this scenario is highly unlikely, because of the wildly different design of the two reactors.
The reason why radiation was disseminated so widely from Chernobyl with such devastating effects was a carbon fire. Some 1,200 tonnes of carbon were in the reactor at Chernobyl and this caused the fire which projected radioactive material up into the upper atmosphere causing it to be carried across most of Europe.
There is no carbon in the reactors at Fukushima, and this means that even if a large amount of radioactive material were to leak from the plant, it would only affect the local area.
The Japanese authorities acted swiftly and decisively in evacuating people living within 20km of the plant, and ensuring people living within 30km of the plant remained in their homes, with windows and doors closed. The radiation measured so far at Fukushima is 100,000 times less than that at Chernobyl.
http://www.guardian.co.uk/world/blog/2011/mar/16/japan-nuclear-crisis-tsunami-aftermath-live
White smoke rose from the No. 3 reactor at Fukushima’s No. 1 nuclear power plant Wednesday and authorities said its containment vessel may have ruptured, spewing a radioactive cloud.
The No. 4 reactor meanwhile suffered another fire.
If the No. 3 reactor’s containment vessel — the final barrier to prevent the release of radioactive substances — is breached, it will be the second among the plant’s six reactors, meaning steps to avoid a worsening situation are not working.
Efforts are continuing to pump seawater on the rods to keep them from melting down. Chief Cabinet Secretary Yukio Edano told a news conference in the morning that smoke had been seen at about 8:30 a.m. around the No. 3 reactor.
“As we saw in the No. 2 unit, steam has been released from the (No. 3) reactor’s containment vessel,” Edano said.
http://search.japantimes.co.jp/cgi-bin/nn20110316x3.html
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