Monday, August 15, 2011

Radioactive Sulphur from Fukushima I Nuke Plant Reached California

UC San Diego researchers found radioactive sulphur (sulphur-35) in the atmosphere that probably originated from Fukushima I Nuclear Power Plant in the attempt to cool the reactors by injecting seawater. Chlorine in the seawater reacted with neutrons from the reactors to produce sulphur-35, which was then transported by a strong westerly wind to southern California, the researchers say.

Their findings were published in the electronic version of the Proceedings of the National Academy of Sciences of the United States of America on August 16.

Here's the abstract from the PNAS (emphasis is mine, in blue):

A recent earthquake and the subsequent tsunami have extensively damaged the Fukushima nuclear power plant, releasing harmful radiation into the environment. Despite the obvious implication for human health and the surrounding ecology, there are no quantitative estimates of the neutron flux leakage during the weeks following the earthquake. Here, using measurements of radioactive 35S contained in sulfate aerosols and SO2 gas at a coastal site in La Jolla, California, we show that nearly 4 × 1011 neutrons per m2 leaked at the Fukushima nuclear power plant before March 20, 2011. A significantly higher Graphic activity as measured on March 28 is in accord with neutrons escaping the reactor core and being absorbed by the coolant seawater 35Cl to produce 35S by a (n, p) reaction. Once produced, 35S oxidizes to Graphic and Graphic and was then transported to Southern California due to the presence of strong prevailing westerly winds at this time. Based on a moving box model, we show that the observed activity enhancement in Graphic is compatible with long-range transport of the radiation plume from Fukushima. Our model predicts that Graphic, the concentration in the marine boundary layer at Fukushima, was approximately 2 × 105 atoms per m3, which is approximately 365 times above expected natural concentrations. These measurements and model calculations imply that approximately 0.7% of the total radioactive sulfate present at the marine boundary layer at Fukushima reached Southern California as a result of the trans-Pacific transport.

The amount is so tiny there's nothing to worry about, says one of the researchers at UCSD:

"The levels we observed are in no way harmful in California," Thiemens said.


STeVe the JeW said...

"The levels we observed are in no way harmful in California," Thiemens said....

laughing my fucking ass off... love the work you're doing thiemens, but you can turn off the mandatory clown comments at the end.

also, it's nice to know that even though japan doesn't give a shit about anybody (especially itself) we still have people capable of understanding what, more or less, is really going on 6,000 miles away.

Anonymous said...

OK, maybe I am dense, but I don't understand where the sulphur element originated from. The big nuclear industry sales pitch is that it is "clean energy" (what an oxymoron) because no sulphur dioxide is produced as there is no sulphur in the fuel. But Fukushima still delivered Sulphur, Sulphur Dioxide (SO2) and Sulphate (SO4).

If anyone knows about how these chemical reactions work & could please tell me:
1) Where the Sulphur element came from in the first place.
2) Is the Sulphur Dioxide and Sulphate produced radioactive as well? Should the US and/or Japan expect to have or have we already had radioactive acid rain?
3) Since scientists believe that Sulphate in the atmosphere causes higher cloud formations & longer cloud lifetimes, could these emissions be the cause of the super tornadoes that hit the US this year?
Any responses will be appreciated.

Anonymous said...

The neutrons emitted from the reactor core hit the chloride ions of the seawater, creating Sulphur-35, which is radioactive. Sulphur oxidizes to Sulphur Dioxide (SO2).

Anonymous said...

There are 6.02214199 x 10^23 molecules (Avogadro's number) in one mole of air. That is a 6 followed by 23 zeroes. There are approximately 41.597 moles of air at sea level and at a temperature of 20°C. Multiplying the two, that means that there are approximately 2.505030 x 10^25 molecules of air in 1 cubic meter at sea level and at 20°C - approximately the temperature and pressure at La Jolla, CA. They found 1500 atoms of sulfur 35 per cubic meter of air. Dividing, that is one atom of sulfur per 1.670020 x 10^22 molecules of air, so we can neglect the weight of sulfur 35 and use the standard calculation for how much a mole of dry air weighs. The molecular weight of dry air is about 0.0289652 kg per mole. Since we have abut 41.597 moles (neglecting humidity) in 1 cubic meter of air at sea level and 20°C, multiplying we have about 1.2048654244 kg per cubic meter of dry air.

There are 6.02214199 x10^23 atoms of Sulfur 35 in one mole. One mole of Sulfur 35 weighs 34.9690321 grams. The specific activity of Sulfur 35 is 1578 TBq/g or 1.578 x 10^15 Bq/g. The specific activity of one mole of Sulfur 35 is then 1.578 x 10^15 multiplied by 34.9690321 grams or about 5.518113 x 10^16 Bq/mole. Dividing by Avogadro's number, one gets about .00000009163041 Bq/atom. Multiplying by 1500 atoms, one results in 0.000137446 Bq per cubic meter. Dividing by 1.2048654244 kg per cubic meter of dry air, we obtain a radioactivity of .000114075 Bg/kg at La Jolla in March. This is a tribute to how good the detectors are.

At Fukushima, there were approximately 200,000 atoms of Sulfur 35 per cubic meter. Repeating the calculations, that would be about .01521 Bq per kg of dry air for Sulfur 35. Again, a very small number.

Now the abstract mentions a neutron flux of 4 x 10^11 per sq. meter. This is odd. Normally, neutron flux is stated as neutrons per sq. meter per second. If the total flux was 4 x 10^11, then this number would have to be divided by the number of seconds of the total time period. Not clear. Moreover, the neutron flux of an operating boiling water reactor is apparently in the range of 5 x 10^13 to 9 x 10^13 neutrons per sq. meter per second or about 100 times higher than the flux in the abstract, assuming the worst case that this flux is per second and not the total flux for the period. This would be consistent with reactors that were successfully shut down with no subsequent criticalities. I would think that this small neutron flux could be due only to decay. So this study may actually be good news in the sense that it appears to confirm that the reactors were successfully shut down.

Morbid said...

What a joke!

Talk about mis-direction...

If there instruments are so great how about reporting on what they found in terms of Sr-90, Pu-239, Cs-137, etc.

These are items of interest.

Inhaling these hot particles is a concern to public health.

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