Tuesday, April 12, 2011

#Radiation in Japan: Strontium-90 Has Been Found in Fukushima

Here we go. And it's safe, I'm sure.

Yomiuri Shinbun (2:06AM JST 4/13/2011):

Ministry of Education and Science announced on April 12 that a minute amount of radioactive strontium has been found in the soils and weeds of 6 cities, towns and villages in Fukushima Prefecture including Iitate-mura, and Namie-machi.

Strontium-90 tends to accumulate in the bones as its chemical structure is similar to that of calcium. However, according to the Ministry, the amount detected this time was very minute and there is no ill-effect on humans. This is the first time that strontium was detected since the Fukushima I Nuke Plant accident started.

Iitate-mura had the highest level of strontium-90 at 32 becquerels per 1 kilogram of soil.




Yomiuri says "it's the first time that strontium was detected". Hmmm. It may be more like it's the first time that the Ministry thought about testing it.

Strontium-90 (Sr-90) is not easy to detect. You have to look for yttrium (Y) and deduce the amount of strontium, and it takes about a week to do the analysis and calculation.

Unlike volatile materials like iodine-131 and cesium-137, "heavier" elements like strontium and plutonium were not supposed to have spread to wider areas. Iitate-mura is about 39 kilometers (24 miles) northwest of Fukushima I Nuke Plant, on a pristine Abukuma Highlands. (Or "was pristine", sadly.)

I'm checking the Ministry of Ed and Science site for the actual numbers and locations..


Anonymous said...

The reason they are finding "heavy" isotopes far from the plant is because micron (μm) sized particles operate under Brownian motion physics. Brownian motion is the microscopic random motion of ultra small particles due to the numerous random collisions by gas molecules. Macroscopically, we see the overall movement of particles from a high concentration region to a lower concentration region. Since it is caused by gas molecule collisions, the effectiveness of this mechanism increases as particle size decreases.


DD04 said...

Interestingly, the testing data being released is for Gamma radiation. What about the Alpha and Beta? And now these are being found further from the site than ever expected. It seems that Japan and the US are making decisions based upon information that is weeks old in a situation that demands up to the minute information. It doesn't instill confidence or trust to me...

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