Talk:Tokaimura nuclear accidents

Wiki Education Foundation-supported course assignment
This article was the subject of a Wiki Education Foundation-supported course assignment, between 15 January 2020 and 1 May 2020. Further details are available on the course page. Student editor(s): Charstutz. Peer reviewers: Historyfan323, Hillmap.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 11:27, 17 January 2022 (UTC)

Re cherenkov radiation
Hi. I've added the qualifier "possibly" to the Cherenkov radiation claim, since there are reasons to believe that it is not -or not completely- Cherenkov radiation- until such time as an expert can help! : D This was a criticality accident. Other criticality accidents have happened in air, with the same 'blue flash'. The only reference I can find to Cherenkov occurring when the medium is air (because the speed of light in air is so close to that in a vacuum) concern very high energy cosmic particles entering our atmosphere. http://hyperphysics.phy-astr.gsu.edu/hbase/tables/indrf.html Another criticality incident concerning liquid, like this article, is http://en.wikipedia.org/wiki/Cecil_Kelley_criticality_accident#cite_note-r1-3 and the viewing windows on the vessel concerned are small, yet observers still describe the flash as being bright. However, I can't find the citation for that part of the article. Given the doubt re Cherenkov and/or 'ionized air', it is reasonable to add the qualifier, and to remove the Cherenkov illustration picture which had no other relevance to this article. For the same reason, it would be reasonable to state "possibly Cherenkov and / or ionized air". I'm not trying to push a POV, but merely trying to avoid misleading readers. Regards. 87.112.234.138 (talk) 18:34, 10 April 2012 (UTC)

As is explained on Criticality_accident, this is wrong, it is *not* cherenkov radiation. I'm not a specialist, though, and I think maybe I should leave fixing this to who inserted the relevant text anyway, he may know best how to judge it now. (I realize that the cherenkov assertion is being made in the referenced text, [], but that doesn't necessarily make it correct of course.) So I'm going to send Greg L a message. --Pflanze2 (talk) 06:53, 19 March 2011 (UTC)


 * I remember reading about the Cherenkov (it’s capitalized) radiation and its blue flash when this happened back in 1999. The following sources speak of the blue flash and that it was due to Cherenkov radiation:


 * Michael E. Ryan (who at the time was the professor of chemical and biological engineering and went on to be vice provost and dean of undergraduate education) of the University of Buffalo – “The Tokaimura Accident”; and
 * Makoto Akashi, Director of Research Center for Radiation Emergency Medicine at Japan’s National Institute of Radiological Sciences: “The Medical Basis for Radiation-Accident Preparedness”, The Parthenon Publishing Group Inc., which states “All three workers saw a ‘blue flash’ and heard the gamma-radiation monitor alarm” (direct link to Google Book page). And “All three observed the Cherenkov light flash” (direct link to Google Book return).


 * More reliable sources can be found with this Google search.


 * Yes, I see that you base your opinion upon what you read in Wikipedia’s own article, Criticality accident, that every single mentioning about how the blue glow is actually ionized air and not Cherenkov radiation (such as this one This blue flash or "blue glow" is often incorrectly attributed to Cherenkov radiation, most likely due to the very similar color of the light emitted by both of these phenomena. This is merely a coincidence) is uncited. Wikipedia is not in and of itself a reliable source; without citations, the assumption is that assertions on its pages that conflict with reliable sources are in error; 9th-grade I.P.s and college students utterly giddy with how educated and wise they’ve become in only three short months wade into our pages all the time.


 * Given that the Director of Research Center for Radiation Emergency Medicine at Japan’s National Institute of Radiological Sciences wrote that it was Cherenkov radiation, we go with him and not a very poorly cited article on Wikipedia. The guy who wrote the book (literally) trumps a sloppy wikipedian who has exceedingly high confidence in his or her grasp of advanced particle physics.


 * Besides, I’m quite well read about the Manhattan project. Some time after the Trinity test, one of the physicists Louis Slotin, was performing a criticality experiment with bricks of plutonium. A brick slipped and he was killed by exactly the same phenomenon (gamma rays, neutrons, and bathed in Cherenkov radiation). Like Hisashi Ouchi, he died. And I see,  once again , Wikipedia’s own article on Louis Slotin does the exact same POV-pushing about how it was ionized air and not Cherenkov radiation—and once again doesn’t cite the notion. I don’t know who is responsible for this sort of thing, but it is exceedingly poor writing practice and will absolutely not be coming here—not given the very authoritative Reliable Sources that can be stacked at the end of the line (which I’ll be adding shortly…)   Greg L (talk) 17:26, 19 March 2011 (UTC)


 * P.S. Having read over our Criticality accident article, it is clear that a wikipedian took it upon him or herself to do some calculations of the required particle energies for beta particles to exceed the refractive index of air. It was all uncited WP:SYNTH and is a clear violation of No original research. Then the conclusions of that propagated throughout the rest of the article. That wikipedian might well be correct. Or that wikipedian could very well be wrong. Other wikipedians expect citations to resolve points of fact that are unusual, very specific, and likely to be challenged. I am quite familiar with the calculations required to double check the math over on Criticality accident and even have pre-made spreadsheets to ensure the relativistic effects are properly accounted for. But that’s not the way these sort of things are done. Generally speaking, straightforward math does not need to be cited. But the intricacies of the nuclear physics underlying the phenomenon exceed the standard of the litmus test: that other wikipedians who aren’t experts in the field be able to double check straightforward math without needing specialized knowledge to know which principles of nuclear physics apply in the calculation and which ones don’t . Given the authoritative and exceedingly reliable sources that are cited here at this article, I hold out a darn healthy skepticism of what I’m reading over at Criticality accident and will certainly not be baited into a “who’s a better particle physicist”-game in poring over the math. No way. Unless the wikipedian responsible for all that stuff is himself or herself a published RS, the assertions written there can not stand on their own as being irrefutably obvious because “God does not play dice with the universe and the math physics are too simple,” or similar such nonsense. My addition of tags  illustrate the proper remedy when faced with WP:OR. Greg L (talk) 18:02, 19 March 2011 (UTC)


 * I 'll make correction to this article. I should note that in sources there is no assumptions of observable Cherenkov radiation in air. Compare observed a blue flash of Cherenkov radiation in the air surrounding ... from article and All three workers saw a ‘blue flash’ and heard the gamma-radiation monitor alarm from source. The catch here is Cherenkov radiation in eyes of those who experience blue light. As structural parts of eye has larger n (and because of that greater Cherenkov radiation intensity per volume unit) than air and not obscured by pupil, this light is more likely is the source of blue flash. As for pictures in which we could see Cherenkov radiation, i should note that they are taken for radioactive materials in water, which has greater n that air, and so we can observe such bright blue light. Nevertheless citation is factually incorrect so I am deleting "in the air surrounding tank" from article.--Diowerefox (talk) 12:31, 24 March 2011 (UTC)


 * I understand your point and agree with your logic. Very good. They saw a blue flash; we don’t know what turned blue. Since the container was an opened-top affair with a 220 millimeter opening (Pg. 14 of the IAEA report), the Cherenkov radiation could easily have been in the water and the blue light reflected off the ceiling. It might have also been flat-out in the air, but the citations are not so specific as to state what, exactly, turned blue; none of the citations say the flash originated in the air, including the IAEA report. Accordingly, as you say, it is proper to just say that 1) they saw a blue flash, and 2) it was attributable to Cherenkov radiation. I will note, by the way, that when Louis Slotin was performing his criticality experiment with bricks of plutonium and one slipped, the blue filled the air and—other than on Wikipedia—the phenomenon is widely attributed by RSs to Cherenkov radiation. But that was with bare bricks of plutonium surrounded in air. It would seem that beta radiation (electrons) might have some difficulty getting through two, 3-millimeter-thick layers of stainless steel. But there certainly would have been extraordinarily intense Cherenkov-caused glow in the water, and the reflective inner surface of the stainless steel tank would certainly direct much of that light out of the tank and into the room. Greg L (talk) 03:05, 25 March 2011 (UTC)

Synthesis due to incorrect interpretation of RSs

 * An edit by an I.P. contributor, effectively stated that the blue glow the operators saw was A) seen in the surrounding air, and B) was due to glowing air that had been ionized by neutrons. The assertion was cited to a highly authoritative RS, the Los Alamos National Laboratory, and their article “Criticality accidents report issued”. While that report does indeed mention the Tokaimura Tokaimura nuclear accident, and in still another section of the article in a different context mentions how neutrons passing through air can ionize the air and make it glow blue, it does not  say what exactly glowed blue that three operators at Tokaimura witnessed, nor does it say that the air surrounding the tank at Tokaimura glowed blue due to ionized air. Thus, that I.P.’s edit suffered from SYNTH, which is wiki-parlance for making an incorrect inference. Very importantly, the uranium at Tokaimura was in water, which certainly glows very, very brightly during an intense criticality burst due to Cherenkov radiation (charged particles exceeding the speed of light in water). Moreover, the tank had an open top. Whereas there might have been blue-ionized air surrounding the tank due to neutron flux (in addition to intensely glowing water), there is no RS that states this occurred at Tokaimura. What is clear is that the article currently has two, very authoritative sources that do state that a blue glow was A) seen at Tokaimura, and B) was due to Cherenkov radiation. One can infer that since Cherenkov radiation is without-a-doubt seen in water (there are several pictures of this on Wikipedia and many others showing water glowing blue due to Cherenkov radiation), and since there was water in a tank, and since the tank had an open top, the blue glow the operators would logically be due to intensely bright water in the open-topped tank shining blue light upwards and scattering about the room. However, no RS is so explicit about Tokaimura. Also… It might seem plausible to some editors that in addition to what would have undoubtedly been an intense flash of Cherenkov-originated blue light from the water, there could also have been ionized air glowing light blue outside of the tank since high-energy neutrons would have no problem at all passing through six millimeters of steel. But again, no RS identified to date is so explicit to state that this was or was not the case. In fact, all the RSs are silent on what, exactly, glowed blue. Accordingly, Wikipedia must properly remain silent on such conjectured details and narrowly constrain itself to the information provided by the RSs: “All three observed the Cherenkov light flash”. We don’t synthesize contrary to the RS, and we don’t add detail and specificity beyond what the RS provide. Greg L (talk) 16:17, 2 April 2011 (UTC)

Hi Greg. I've looked at one of the RSs (citation #4,) and to quote it: "The blue flash that they had seen was a result of the Cherenkov radiation that is emitted when nuclear fission takes place and ionizes air." This is not what Cherenkov radiation is. 87.112.234.138 (talk) 19:00, 10 April 2012 (UTC)

The use of the term nuclear disaster
For the first accident, an explosion in a plant that exposed 40 workers to radiation, I removed the term nuclear disaster. I'm uncertain as to retaining the term for the criticality accident, as there was injury, loss of life, an evacuation, etc. Does anyone have thoughts on the usage of the term nuclear disaster?Wzrd1 (talk) 00:47, 19 November 2013 (UTC)

This page desperately needs modification
At a rough guess from quickly skimming this page, I'd say about half of this page is either plain wrong or misleading due to being half wrong or lacking in detail. Until yesterday when I changed it, for instance, the very first sentence said that both accidents occurred at the Tokai nuclear power station, even though neither of them did.

I was just going to leave it at that but then I realised that I have two weeks off work because of the Christmas holidays, so I'm just putting it out there that I'm going to try and find the time to update this whole page to more accurately reflect these two accidents - neither of which had anything at all to do with each other apart from occurring in the same geographical area. 82.47.246.98 (talk) 22:16, 24 December 2021 (UTC)

Hisashi Ouchi
The way that Hisashi Ouchi is treated is unacceptable. He suffered one of the most brutally painful and slow deaths in history and they kept him alive   a g a i n s t   his will - and the way he is treated here is as if his treatment and death were humane and according to his will. unacceptable GeorgeMarg (talk) 13:38, 29 May 2022 (UTC)
 * what is the evidence it was against his will? 2601:642:C481:4640:C1D:B27B:F086:55E6 (talk) 18:49, 25 March 2023 (UTC)
 * Lare response to a late response, but per this Reddit summary of A Slow Death about Ouchi’s tragic ordeal, Ouchi lashed out during a painful treatment session, famously saying he was “not a guinea pig” and wanted to go home. But he never voiced any explicit wish to die and seemed to lose consciousness about 53 days in. Also, doctors were legally obligated to keep him alive even after his case was pretty much hopeless as the family had not issued a “do not resuscitate” order. There’s a ton of misinformation about this case due to its gruesome nature attracting morbid curiosity so finding reliable sources is difficult. If anyone has a copy of the book it’d probably be an excellent source. Dronebogus (talk) 01:14, 9 November 2023 (UTC)

Wiki Education assignment: Content Area Literacy
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Source cited does not support claim
The source cited for the claim that residents were asked to lend any gold they had for testing says nothing of the like. It mentions something made of gold that was tested, but nothing about how that came to happen. Dfeuer (talk) 22:31, 12 January 2024 (UTC)