Tuesday, April 5, 2011

#Fukushima I Nuke Plant: Radiation Level of "1,000 Milli-Sieverts and Over" - Exactly How Much Over?

One minor detail is bothering me.

Does anyone know whether there's a portable dosimeter that can measure beyond 1,000 milli-sievert?

What's been bothering me about the high radiation at Fukushima I Nuclear Power Plant is that the government (NISA) or TEPCO simply says "the radiation at such and such place was above 1,000 milli-sieverts."

Above 1,000 milli-sievert BY HOW MUCH?

I've seen an occasional slip or two where the newspapers report that TEPCO/NISA didn't really know how radioactive it was (whether it's air inside the Reactor 2 building or the water from the pit by the ocean), because the needle of the dosimeter immediately swung to the max (1,000 milli-sievert).

And that was precisely the case with the pit water. TEPCO made a worker measure the radiation about 1.2 to 1.4 meters from the surface of the pit water, and the worker couldn't measure it because the needle of the dosimeter immediately swung to the max. So they announced it was "over 1,000 milli-sievert/hour".

(If it swung to 1,000 milli-sievert in 1 second, would that mean 3,600 SIEVERT?)


Anonymous said...

I've had the same problem. I can't find a counter that goes over 200 millisieverts. I've read that modern counters don't go very high because we are more concerned with lower levels than during the threat of atomic warfare.

Someone, somewhere has counters that go to Chernobyl levels. Probably the Russians...

Anonymous said...

See my first post here for the answer to your question.


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