Possible recriticality - I-131 detected in Japan

Airborne I-129 and I-131 can be inhaled. In the lung, radioactive iodine is absorbed, passes into the blood stream, and collects in the thyroid. Any remaining iodine passes from the body with urine.

In the body, iodine has a biological half-life of about 100 days for the body as a whole. It has different biological half-lives for various organs: thyroid - 100 days, bone - 14 days, and kidney, spleen, and reproductive organs - 7 days.

http://epa.gov/radiation/radionuclides/iodine.html

Tdm- There cannot be any

Submitted by BC (not verified) on Fri, 2011-09-09 16:26.

Tdm-

There cannot be any I-131 left from the original March-April events, as whether or not is in a body, it decays away to stable iodine in much less time than a hundred days.

This fresh I-131 is very distubing.

Fresh I-131

Submitted by Concerned Citizen (not verified) on Fri, 2011-09-09 17:45.

Greetings to all!

I have been quietly monitoring the discussions on this board since the Fukushima explosions. When BC says something is "very disturbing" it occurs to me that perhaps I should start looking for a good deal on a high end respirator mask. How much danger are we in, BC?

In the course of these discussions I have found the remarks of the BRAWM physics team somewhat reassuring. On the other hand I am not at all reassured about the safety of nuclear reactors when we have schoolchildren in Japan getting nosebleeds, and a Fukushima NPP worker coming down with acute luekemia and dying within one week of his arrival at Fuku.

I am deeply disturbed by the horrifically tragic aftermath of the forced evacuations where previously well cared for and humanely treated livestock that were left trapped dying in thier pens with only a few venturesome videojournalists looking in on them. I'm a grown man and I am not ashamed to say these videocasts brought tears to my eyes. These kinds of outcomes where huge square mileages of landscape are rendered uninhabitable for centuries are completely unacceptable IMO. If these were gas fired plants that exploded we could still soon go back in there and safely retrieve the animals! Nuclear power plants are no dam good in emergency situations such as earthquakes, they have to be shut down for saftety reason and then fed much needed electricity while they are shut down in order to get rid of the "decay heat".

This is all just wrong...

Also, I do not understand why you fellows and/or ladies are only looking at the doses emitted by a few isotopes at a time and ignoring dozens of others, technetium-XXX, Tellurium-XXX, Americium-XXX and so on and on... Should not the total dose from other isotopes that are not being measured be integrated into the dose from the few isotopes that are being measured, in order to arrive at a figure that can be compared to living in Denver or flying across the continent?

Thank you for your attention and I will appreciate your kind response as soon as possible, before I click on that Respirator on Ebay...

Regards,

James

recriticality

Submitted by a female faust (not verified) on Fri, 2011-10-07 06:43.

in Mr. Arnie Gundersen's opinion, there has indeed been criticality.

Certainly, how else to explain neptunium in June? Among other anomalies.

This has precedent: Idaho falls, 1961 ("By the time help arrived, one man was found dead. A second technician was rushed outside, but was so radiated that he had to be examined by a doctor wearing protective clothing. The second man quickly died. The third technician was found dead on the ceiling of the reactor building. A piece of control rod was jammed through his groin, pinning his corpse to the ceiling at the shoulder" -- Bill Keisling, The Fukushima Experiment text corresp. note 9 - 10), and it also has more recent, more entertaining, if less common-sense explanations.

Don't listen to Gunderson

Submitted by Anonymous (not verified) on Fri, 2011-10-07 07:35.

Gunderson has repeatedly shown that he doesn't know beans about neutron transport theory, and wouldn't know the Boltzmann equation if it was plastered on a billboard.

My fellow scientists and I think his ramblings are only good for laughs.

The reason the anti-nukes like him is that he tells them what they want to hear.

recriticality &c.

Submitted by a female faust (not verified) on Fri, 2011-10-07 06:47.

(cut off) in any event: isn't recriticality attendant upon the melt-through scenario? for the fuel most certainly has gotten out. even if it is not always to be expected in this context -- it has indeed shown:

Fukushima in Recriticality: I-131 Detected in 4 Locations: Tokyo, Iwate, Nagano, Niigata.

p.s.: i am self taught, do correct me should i err; thank you all for your patience if i am unclear.

Iodine-131 being detected in

Submitted by Anonymous (not verified) on Fri, 2011-10-07 07:48.

Iodine-131 being detected in sewerage around japan without the correspondent increase in radioactive cesium levels can't be from a criticality, which would produce both, but most probably from medical waste or patients excreting it after radiation treatment with Iodine-131.

Recriticality

Submitted by Anonymous (not verified) on Fri, 2011-10-07 07:28.

In the case of the SL-1 incident to which you refer, a criticality occurred when one of the operators was manually withdrawing a control rod. When the reactor cover which holds the control rod drives is removed, the control rods have to be disconnected from their drives, so that the drives and cover can be removed. In order to reattach these rods, they had to be manually pulled up a short distance to reattach to the drives. In the SL-1 case, the rods got stuck. The operator was pulling hard to free the stuck rod, and when it came loose, he ended up withdrawing the rod more than he should have.

The SL-1 incident led to a rule that control rods should never be moved manually.

Nobody should be moving control rods at Fukushima. As far as a melt through helping criticality; just the opposite is true. Fuel that melts through is no longer contained, but can spread out, which would tend to prevent criticality.

When I said that the I-131

Submitted by BC (not verified) on Fri, 2011-09-09 20:10.

When I said that the I-131 was very disturbing, I meant that it indicates that things are not as in-control as we have been led to believe. I do not think those of us in the US have reason to be overly concerned for what has happened at this juncture so much as what could happen, and our non-existent lead time to deal with said possible events.

In other words - if this thing goes completely up, will we know in time to shelter? To split town? Would it matter?

I am mostly in agreement with the risk assessment that the BRAWM team has presented for events thus far, and I know that I have much more pre-2011 man-made-radioactivity in my back yard than I do Fukushima fallout, and that all of that is dwarfed by natural radioactivity. But I also know that a good bit of Japan is screwed for a long while, and suspect that if things go sideways we will all likely find out after the fact.

So, don't panic. But damn, it sure seems like Fukushima is a long ways from over, even for the States.

The Iodine-131 seems to be

Submitted by Anonymous (not verified) on Sat, 2011-09-10 09:18.

The Iodine-131 seems to be from medical use. Similar levels detected in Japan from 84 to 93: http://www.journalarchive.jst.go.jp/jnlpdf.php?cdjournal=jhps1966&cdvol=...

Thanks. Max value I could

Submitted by BC (not verified) on Sat, 2011-09-10 09:43.

Thanks. Max value I could find in the paper you linked was 730bq/kg, and there wre also a few in the 300-500bq/kg range. So nothing directly equivalent to the largest number seen (2300bq/kg), but close

This does give some perspective - this new I-131 may not be FK related after all.

Again, thanks for data.

Possible recriticality - I-131 detected in Japan

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