Friday, April 29, 2011

Japan's Nuclear Nightmare

In spite of a dearth of information, here is how I see the Japanese nuclear situation.

When the U.S. DOE provided maps of the nuclear contamination http://blog.energy.gov/content/situation-japan I calculated the total release, getting 5.9 million curies (5,900,000). That is about 1/10 what Chernobyl released.

But, I found an error in my calculations - I had assumed point sources beneath the radiation detectors. Actually each detector received radiation from directly below it, and from the areas nearby, and from everywhere out to the horizon. When I calculated assuming a spread-out source, I got just 15,000 curies released. Which one is more accurate? That depends on how the U.S. DOE did it's calculations.

The DOE maps do not show what they detected - the airplanes flew several hundred feet up, and detected radiation at that level. They then put out maps showing how bad it is at knee high (one meter). Unless I can see how they re-calculated to get what they reported, I cannot be sure how accurate my calculations are.

Before I could get someone to check my modelling and my math, Japan's nuclear safety agency reported that the total release was 5,000,000 curies, or 1/10 of what Chernobyl released (check this, http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1304052023P.pdf , second page, red line near the bottom).

I was so disheartened that I made no new blog entries for 26 days.

BUT ... Japan also reports that the maximum dose to infant's thyroids will be less than 50 Rem. That is consistent with 15,000 curies, not with 5,000,000 curies.

Did Japan's nuclear safety agency make the same mistake that I made? Are they now afraid to correct their published error? I hope so.

All the information I have says, the release was less than 150,000 curies.

A nightmare; a disaster; but not a Chernobyl and not a catastrophe.

Not enough to cause more than about 40 deaths to members of the public.

The Fukushima 50 are a different matter. Their doses are quite high; they may have sacrificed their health, or even their lives, to keep the rest of us safe. May God bless them and keep them - and theirs.

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