http://www.guardian.co.uk/world/2011/mar/16/fukushima-workers-
evacuate-radiation-spikes
http://tinyurl.com/6kr55hs
"The workers were ordered to leave the facility after the level of
radiation at the plant soared to 10 millisieverts per hour – above
the level considered harmful to human health – possibly as a result
of radioactive substances being emitted from the No 2 reactor. The
reading later fell to around six millisieverts per hour, reports
said, and they were allowed to return."
"The crisis unfolding in Fukushima continued to raise anxiety levels
in Tokyo, 150 miles to the south. Radiation levels in the capital
were 10 times higher than normal on Tuesday evening, but posed no
health hazard, the government said."
The annual limit of exposure for nuclear plant workers is 20 mSv.
Five Sv is fatal within a month to half of those receiving that
dose. See:
http://www.world-nuclear.org/info/inf05.html
Also of genera interest from the above site: "Backscatter X-ray
scanners being introduced for airport security will gives exposure of
up to 5 microsieverts (μSv), compared with 5 μSv on a short flight
and 30 μSv on a long intercontinental flight across the equator, or
more at higher latitudes – by a factor of 2 or 3. Aircrew can
receive up to about 5 mSv/yr from their hours in the air, while
frequent flyers can score a similar increment."
Radiation has at one time reached 0.4-1.0 Sv/hr at one point and
location at Fukushima.
If there is plutonium, from the No. 3 reactor, in the plume that hit
Tokyo then that level of radiation could be harmful. An inhaled
microscopic amount of plutonium can cause lung cancer.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
