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rich.pell
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Re: Freezing contamination
rich.pell   9/11/2013 5:41:37 PM
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"... it does indicate that the liquid stored in these tanks are highly radioactive. No?"

Yes, it seems very likely that this measurement is representative of the radiation level of the water stored in the tanks, which would certainly make it highly radioactive in terms of beta radiation (but not - as would be assumed from most reporting on this topic - in terms of the more worrisome gamma radiation with its much higher potential for biologic damage). 

patrick.mannion
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Fukushima design lesson
patrick.mannion   9/11/2013 8:45:49 AM
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hey mohovO, maybe one design lesson from the disaster is: Don't put critical backup-generators in the basement if you're building a nuclear power station near an ocean. No matter how high you build those water barriers, you're asking for trouble.
 


rich.pell
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Re: Freezing contamination
rich.pell   9/11/2013 8:09:26 AM
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Hi Junko,

No apologies necessary - it was difficult to distinguish the stated number even with headphones.  And in either case - "15" or "50" - it was not a significant difference.

junko.yoshida
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Re: Freezing contamination
junko.yoshida   9/11/2013 1:21:32 AM
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Thanks for the link to Tepco's press release. Although the figure of 1,800 mSv/h may not represent the radiation level of "the whole area", as Tepco says in its own release, it does indicate that the liquid stored in these tanks are highly radioactive. No?

junko.yoshida
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Re: Freezing contamination
junko.yoshida   9/11/2013 1:11:45 AM
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Rich, thanks for the corrections. Much appreciated. I misheard the number of those who died among 6,000 who got thyroid cancer in Chernobyl (i was watching the video clip in a noisy place). I apologize.

rich.pell
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Re: Freezing contamination
rich.pell   9/10/2013 10:17:42 PM
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It's certainly true that TEPCO has done a poor job (to say the least) at releasing information in a clear and useful manner.  For example, in the case of the reported radiation level of 1800mSv/hr, it appears it was a measurement taken from about 5 cm above a water puddle near one of the tanks.  The reading at a distance of 50 cm was only 15 mSv/h.  In addition, this radiation was almost entirely beta (as opposed to gamma) radiation, which can be easily blocked and/or safely avoided by maintaining a distance.  The reports that the radiation measured in this case constituted a "lethal dose" were erroneous.

rich.pell
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Re: Freezing contamination
rich.pell   9/10/2013 9:40:12 PM
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Hi Junko,

I believe the WHO health risk assessment report was released early this year, and was based on data from a 2012 report. (It is true that this is before the latest radiation leaks, but there is no indication that anyone has seen increased exposure as a result of the latest leaks.)  The increased risks for those living in the most affected area are statistical over a lifetime, and mostly apply to those exposed as infants. 

The accident at Chernobyl was far worse, and, unlike at Fukushima, some of the workers at the plant did die as a result of radiation exposure.  And of the 6,000 cases of thyroid cancers in the population living in affected areas - a result of mothers unknowingly feeding their children milk contaminated with high levels of radioactive iodine - there were "perhaps 15" people who had died.  



junko.yoshida
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Re: Freezing contamination
junko.yoshida   9/10/2013 12:09:49 PM
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And one more thing. What we know and what we don't know, so far, is pretty much dependent on what information Tepco and the Japanese government have released -- especially when it comes to the latest contaminated water leakage.

There was a report earlier this summer that says that radiation levels near one of the tanks were 1,800 millisieverts per hour. As Arjun Makhijani, a nucler scientist, points out, "This is an extremely high level of radiation. A few hours basically constitutes a lethal dose."

Why was this not reported sooner?

According to Tepco, they did the first measurement with an instrument that only went up to a hundred millisieverts and maxed.

Well, your science is only as good as your test and measurement tools, isn't it?

 

junko.yoshida
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Re: Freezing contamination
junko.yoshida   9/10/2013 12:01:36 PM
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Hi, Rich. I don't think I disagree with you on the basic science. But where we disagree is our interpretation of the science.

For example, I did take a look at the WHO's report. I take a particular note that this was issued in May 2012 based on data made available in 2011.

Indeed, it says that there is no big health risks outside Japan, but the report does point out an increased lifetime risk for thyroid cancers in certain age & sex groups in the areas most affected.

Now, I also want to point out that this  was all reported before the radioactive water leaks were discovered.You may say that this is also no big deal because the ice wall will stop it. But first, the ice wall is not even built yet. Second, how this will actually work on a massive scale and a long duration Fukushima is planning on remains unproven.

I don't want to be the one to do so-called fear mongering, but for those who work at the nuclear power plant in Fukushima and for those who live in the affected area, there is not much comfort in knowing "only 50 died out of 6,000 affected in Chernobyl" as told by one of the scientists in the video clip: Fukushima and Chernobyl: Myth versus Reality

junko.yoshida
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Re: Freezing contamination
junko.yoshida   9/9/2013 7:56:16 PM
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mohov0, thank you for your kind words. 

All those questions you raised in your comment -- in regards to preventive maintenance electronics technology that could ensure the Tokyo Olympics -- are good ones. We will be surely following them up. Thanks, again.

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