Saturday, March 19, 2011

Reactor Summary & Iodine Precautions



Happy St. Patrick's Day.

Here's the latest from my research on the nuclear situation in Japan.

Workers at the Fukushima power plant are facing a quadruple  meltdown, with 4 out of 6 reactors suffering fire or explosion, and with active reactors #1,2,3 all having partial core meltdown.  Reactor #4 was offline for the quake, which surpisingly is worse: its active (not spent) fuel rods caught fire after boiling off their protective layer of water.  This means that if these rods so much as tipped over (eg due to 30 magnitude 6 aftershocks), they could "Turn On" and restart nuclear fission.  In the words of the Japanese power company "re-criticallity is possible".

If you didn't see it already I made a presentation to my class today on
nuclear reactions and this event:

http://www.physics.sfsu.edu/~chris/astro115/lectures/lec23.pdf

Another concern is that reactor #3 was using reprocessed nuclear fuel containing Plutonium (called "MOX").  Plutonium is not only hightly radioactive, it is also chemically lethal in small quantities.  The brave workers trying to put out the fires and cool the reactors are probably taking huge radiation levels.  They are now running in for 15 minutes, then swapping out.  If the situation deteriorates further, it  may be necessary to send in suicide volunteers, or as they called them at Chernobyl (after the real robots failed) "biorobots".

http://news.nationalgeographic.com/news/2011/03/110317-japan-reactor-fukushima-nuclear-power-plant-radiation-exposure/

By the way the Wikipedia page on the event is surpisingly comprehensive, including listing how much uranium/plutonium fuel is being stored vs. in the reactor cores.

http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents

Meanwhile the UN is monitoring the radioactive plume as it moves downwind. What appears certain is that it will hit the western US tomorrow:

http://www.nytimes.com/interactive/2011/03/16/science/plume-graphic.html?ref=science

What's uncertain is how dangerous it is.  Given the potential for dilution over such a large area, its unlikely to be concentrated right now. However the US NRC officials have already said that it will be WEEKS not days before this is over.  So think of this as the beginning of a long exposure.   (comparison: walking behind a plume of car exhaust for 10 seconds vs. begin stuck in traffic for hours while in a convertable)

As you've heard, potassium iodine (KI) tablets are begin given to local people and US Troops in Japan, and there's been some panic buying here in the US, in spite of the fact that most health officials here are not recommending buying/taking the tablets here.  I think this is a good recommendation for them to make because frantic panicky people are likely to do something dumb like overdose on KI.    But none of us are frantic panicky people, so what action can we take?

Regarding Iodine: this is the most serious preventable risk.  The I-131 isotope concentrates in the thyroid where it decays and causes cancer. Children are the most vulnerable since thyroid cancer takes years to develop.   (Many of the Chernobyl victims were children who died of Thyroid Cancer)

If the body already has all the iodine it needs, then it won't take in any radioactive I-131 that comes by in the air.  For normal people (those who are not alergic to Iodine), the biggest risk in taking iodine appears to be rashes or nausea if excessive doses of Iodine are taken.    Remember that Iodine is a nutrient, we need to consume a small about, roughly 100 micrograms (not miligrams) per day, according to World Health Organization, who suggest increased intake of 280 micrograms for lactating mothers.  (It is required to produce something called T3 and T4 which I think are hormones)




http://www.uned.es/pea-nutricion-y-dietetica-I/guia/PDF/DRI%20-%20Recommended%20Intakes%20for%20Individuals%20-%20General%20-%20USDA%202004.pdf


http://www.who.int/nutrition/publications/WHOStatement__IDD_pregnancy.pdf

If you want to "fill your quota" of Iodine, how best do so if you don't want to buy and take KI tablets, which contain high levels of Iodine (miligrams)?   Here's some thoughts (remember 100 micrograms per day is normal...if you get a little above that they you probably won't retain any environmental iodine)

1.) Iodized Salt:  Several sources I've seen say this does not provide
enough iodine  to prevent I-131 uptake.  Bummer!

2.) KI tablets: as I mentioned these have such high doses that they are
not recommended yet in the US

3.) Iodine crystals:  Used for purifying water worldwide.   A solution of I crystals in water yields 1 gram for every 3 liters of solution at room temperature. (wikipedia & other sources)  So if you had a 1 full liter of iodine solution, it would contain 1/3 gram of iodine.  But usually we just use one capful, which is 5 mililiters.   So each capful contains 1.6 miligrams of iodine = 1,600 micrograms.  This is about 10 days worth of your daily iodine intake.    No wonder the bactria don't like it at this level.     So if you take a capful of iodine and put it in a 1 liter bottle then slowly drink that bottle over the course of 1 week, you'll get a dose of a little over 100 micrograms per day, which will be enough to saturate your thyroid with sufficient iodine, especially if you are getting some dietary iodine, which you SHOULD be, esp. if you are akid or a lactating mom.

(Note for my PCT friends.  This means that on the PCT I took: 8 liters of water per day * 1 capful per liter (min!) * 1,600 micrograms I per capful= 12,000 micrograms per day for 186 days!!!!  With no ill health effects...except occasional excess gas ;)  By the way that's 2.3 whole grams over the course of 1/2 year.

4.) Dietary Iodine.

You can get Iodine through food with out having to drink that smelly iodinated water.  Best food to go for is seaweed, and apparently the Kombu is the best type  see the chart at the bottom of this article:

http://davidgrotto.wordpress.com/2011/03/16/natural-food-sources-of-iodine/

Good luck and please let me know if you have any additional information or have found anything wrong with the information I've presented.

Best wishes,

-Chris

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