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For an accident causing release of radioisotopes, of major relevance for readers is learning the quantitative amount of radiation exposure resulting from such. As implied in WP:RSUW, reliable sources are to be favored, and undue weight should not be given to non-reputable sources by only highlighting their claims without equally highlighting the conclusions of reputable sources.
That the summary of this article highlights global consequence claims from political activist groups like Greenpeace, while questionable, is arguably acceptable as long as such is combined with also reporting at least a bit of the global exposure analysis of a more official source, the United Nations UNSCEAR. Accordingly, I have not deleted any of even the most extreme claims but have aimed to mix in a little info from a more reputable source, keeping such together in comparable highlighting.
Without that, wording of this article's summary would be providing a very misleading impression (generous to not call dishonest) to many readers, so as to make them assume only the likes of Greenpeace considered more than local exposure, not even realizing the UNSCEAR has estimated exposure over a multitude of countries in depth as seen in their vast expansive scientific reports.
Recent history:
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Upwards of 0.3 million recovery workers received a mean dose of 150 mSv (milli-Sieverts) each in 1986.[11] The report to the General Assembly of the UN notes average exposure over the far broader entire populace of the Northern Hemisphere was 0.04 mSv in the year of the accident, and, after decrease over time, residual exposure was a global average of 0.002 mSv/yr in 2008 (separate from other sources of radiation exposure such as an average of 2.4 mSv/yr from natural sources).[11]
...
That way of organization is debatable; I would not have tried it except for his remark. In any case, though, in contrast to what I think he wanted me to do, the summary can not solely highlight the activist claims while simultaneously burying the UNSCEAR info only very many pages deep within the document. A large portion of readers would not keep reading to find it if they thought the former was an authoritative summary, not realizing the violation occurring of Wikipedia's policy on undue weight. (Just like, in almost any context, any web page from Wikipedia to unrelated sites, if looking at hit counters, typically only several percent or less of readers will click on any link for further explanation, an article as lengthy as this will have many readers just reading the summary alone; the summary should not be excessively misleading).
...
Another UN agency, UNSCEAR, has estimated a global collective dose of radiation exposure from the accident "equivalent on average to 21 additional days of world exposure to natural background radiation."[10]
...
The quoted part is a short direct quote, from the UNSCEAR, via an IAEA article. The UNSCEAR report itself estimates exposure, for the total worldwide figure which is higher than local populations alone, amounted to 200,000 man-Sv in the first year and would be a total of around 600,000 man-Sv as a dose commitment. (The dose commitment is that including part received over decades, some yet to be received in the future).
A reader may not know exactly how much the "equivalent on average to 21 additional days of world exposure to natural background radiation" may mean in excess cancer mortality (and there is even debate in the scientific world over such as the LNT model versus alternatives), but it is still far more knowledge than the assumptions of many readers if carefully kept uninformed. (For instance, surveys have shown a huge percentage of the general public does not know any natural radioactivity even exists and thus would presumably assume manmade accidents like Chernobyl caused to the average person in the world the equivalent of decades of exposure to average background radiation; Chernobyl was a terrible accident, the worst by far, something to learn from and avoid, but giving impressions orders-of-magnitude off is not the proper purpose of an encyclopedia).
One will see if that addition gets deleted by the same user, by Apostle12, under a new creative excuse. If so, that fourth revert in a row, each time doing nothing but deleting everything I add, would be a violation of WP:3RR in spirit. While in this case not all within a 24 hour period, Wikipedia's three-revert rule discussion notes how it does not in practice have to be within literally a 24 hour period alone to be unacceptable.
Sokavik ( talk) 21:15, 17 May 2012 (UTC)
Regarding your monetary analogy, global GDP (the total sum of everyone's income) would be a relevant figure, such as knowing if a particular economic event changed global GDP by 0.0001% or by 40% or any other number, for at least some idea of the order of magnitude.
Getting back to the matter of the sum of radiation doses:
As one example, under the common LNT model (linear no-threshold), the amount of cancer mortality would be proportional to the number of people exposed times their average dose each, thus proportional to the collective dose. In the LNT model, each person-Sievert would be approximately comparable in the chance of a cancer death it statistically corresponds to, whether a given person-Sievert comes from one group of 100 people receiving 10 mSv each or another group of 1000 people receiving 1 mSv each.
The LNT model is debatable, but, in any case, having some quantitative idea of average public radiation exposure is better than having no idea even to within orders of magnitude.
As an example of a much different figure, if a far lesser thought-experiment accident (not Chernobyl) caused 0.06 man-Sv instead of 600000 man-Sv collective dose, a conclusion could be made practically even from knowing that fact alone that the thought-experiment accident was not likely to have caused many cancer deaths (whether it was 0.06 mSv to one person or 0.01 mSv to six people or other examples), since such could be compared to the around 160+,000,000 man-Sv received per decade by the world's population from natural background radiation (which itself varies).
For instance, if one source of radiation exposure causes X man-Sv effective dose; another causes 1000 * X man-Sv dose; and one knows the observed cancer mortality caused by the latter could not be more than Y as an upper limit for a variety of reasons; then one would have at least a perspective if reading a claim by questionable sources that the former caused orders of magnitude more than 1/1000th of Y number of cancer deaths.
More than any other source, the UNSCEAR does have tables of radiation exposure estimates by country and region. For instance, the 8.8 PBq of Cs-137 deposited in Central Europe caused an estimated collective dose of 49000 man-Sv in the first year and 166000 man-Sv total dose commitment over decades, with the population of Central Europe (178 million at the time) receiving on the order of around 0.9 mSv each on average from such. The corresponding figure for West Europe was around 0.15 mSv each.
I could list the countries counted as in each region or figures for smaller regions. However, I won't get too much more verbose here.
For some basis of comparison, lifetime exposure to natural radiation varies by hundreds of mSv between many countries, even as country-wide averages, multiple mSv/yr
http://upload.wikimedia.org/wikipedia/commons/5/55/Natural_Radiation_Atlas_of_Europe.jpg
Anyway, the article states global effect (mortality) claims from activist groups. Aside from any debate over sources, it is correct to include global figures (not just local alone) ... and that applies to UNSCEAR as much.
With that said, personally I would be totally fine with highlighting that average global exposure is different from local averages, a reminder in case not already obvious. Such is exactly what I did in my first 2-sentence version of the addition, before trying this more concise 1-sentence version. The original was:
...
Upwards of 0.3 million recovery workers received a mean dose of 150 mSv (milli-Sieverts) each in 1986.[11] The report to the General Assembly of the UN notes average exposure over the far broader entire populace of the Northern Hemisphere was 0.04 mSv in the year of the accident, and, after decrease over time, residual exposure was a global average of 0.002 mSv/yr in 2008 (separate from other sources of radiation exposure such as an average of 2.4 mSv/yr from natural sources).[11]
...
For instance, one could write:
...
Another UN agency, UNSCEAR, has estimated a global collective dose of radiation exposure from the accident "equivalent on average to 21 additional days of world exposure to natural background radiation"; individual doses were far higher than the global mean amongst those most exposed, including 300000 local recovery workers who averaged an effective dose equivalent to 60 years of extra background radiation exposure each.[10]
...
The current version of the article at the moment I am writing this is also okay as far as I am concerned. I just wrote in Talk to prepare for a likely fourth deletion of my edit by the other guy, after the prior three in a row. While I suspect it might happen in the next few hours, if it doesn't, then matters are good.
Sokavik ( talk) 00:39, 18 May 2012 (UTC)
its nuclear bombing not atomic bombing. please correct your physics error — Preceding unsigned comment added by 96.2.38.144 ( talk) 19:18, 24 May 2012 (UTC)
The top paragraph ends: The battle to contain the contamination and avert a greater catastrophe ultimately involved over 500,000 workers and cost an estimated 18 billion rubles, crippling the Soviet economy.
Does anyone know enough about all of that to come up with a comparison amount? Or has it been calculated somewhere by some experts? — Mwr0 ( talk) 15:45, 4 June 2012 (UTC)
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The 'total death toll' number given in the article is misleading. While it references the WHO article on Chernobyl (#14) the actual number in the article doesn't match to that source data. What's more, even in the source data the number given is very clearly listed as a 'guess' which is not terribly well supported. While it is an educated guess, it is a guess nonetheless and could be wrong and indeed very wrong. As such the number given in the article is misleading.
The actual KNOWN FACTS (positive as opposed to speculative) on the Chernobyl disaster death toll are 31 workers and firemen in the intitial event. Two of those died from the explosion proper, and the others from Acute Radiation Sickness in the following weeks.
In addition there was an increase in thyroid cancers in the region directly attributed to radioactive iodine exposure, primarily in children. Roughly 9000 cases were recorded, however the survival rate of was in the vicinity of 99%. So probably in the vicinity of 90 additional deaths that can be reliably attributed to radiation exposure. Interestingly, the fear of radiation exposure almost certainly contributed to the high survival and detection rate as everyone was so sensitive about the matter.
The claim of 'thousands' of deaths, however, is problematic. Yes, since 1986 lots of people originally from the region have died of cancer. However in a 25 year period sections of any population will expire from cancer and the population in question is known to have higher than global average rates of tobacco and alcohol use as well as poor nutrition. Reputable studies, when not speaking apocryphally, make it clear that the death toll and cancer rate amongst those thousands exposed at the time of the disaster is no higher than control groups without exposure from similar regions/cultures.
In other words, while some of those cancers may have been as s result of Chernobyl exposure, there is no way to prove how many, if any and the overall number of people suffering from these diseases is no higher than those in non exposed groups. Or, put more simply, if you were living in Pripyat in 1986 at the time of the accident and died in 2006 from lung cancer did that cancer come from reactor exposure or chain smoking cigarettes your entire life? Given that no reputable study that I have been able to find shows an increase cancer rate over non exposed similar populations, the actual provable, reliable and meaningful death toll as a result of radiation exposure and other direct disaster related effects (such as being blown up) should really be in the vicinity of around 130 people.
All that said, the SOCIAL impact of the disaster, the relocation and the like has been huge and caused all manner of psychological issues etc. but those effects have not been shown to be any more severe than similar populations that survive earthquakes, tsunamis and the like. The disaster was still a disaster, but the social consequences were far more significant than radiation exposure.
Feel free to check sources yourself, but the number at the wiki page is misleading and anyone quoting it without referring to the original source will be quoting a number not supported by actual research. A more accurate statement would be "the scientifically provable death toll is somewhere between 120 and 150 including cancer sufferers from radioactive iodine exposure. While there were many fears of increased health issues due to radiation exposure, scientific studies have not shown a statistically higher occurance of these maladies in the exposed population in comparison to similar populations which were not exposed."
That leaves people quoting a much more accurate PROVABLE number rather than the entirely unproven number of 3500 (ish) which has come down greatly from originally listed estimates of tens to hundreds of thousands which were completely out to lunch.
In short, there has been 25 years of fear mongering about the Chernobyl disaster. Now that we have real numbers and actual studies on the true medical impact, it would make sense to shift our focus away from the terrifying 'N' word and toward the tremendous social and economic damage caused by the meltdown of reactor #4. Those are the real issues and it's about time we focussed on those.
64.4.88.2 (
talk)
15:34, 6 July 2012 (UTC)
The page states "Toptunov mistakenly inserted the control rods too far - the exact circumstances leading to this are unknown because both Akimov and Toptunov were killed during the later explosion." however, Alexander Akimov states that Akimov survived the initial explosions and died two weeks later from radiation poisoning. Which is correct? — Preceding unsigned comment added by 2.98.162.171 ( talk) 16:22, 14 July 2012 (UTC)
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In the Human impact section can we edit the sentence "The predicted 4000 deaths from the UN is based on the Linear no-threshold model (LNT), which assumes that the damage inflicted by radiation at low doses is directly proportional to the equivalent dose." to say 9000 instead of 4000?
I suggest the start of the sentence should read "The WHO's prediction of 9000 deaths in surrounding countries [citation as below] is based on the linear no-threshold model (LNT), which ..."
This is because the Chernobyl_disaster_effects article states that the UN agency (WHO) has revised its number of cancer's to 9000, citing http://en.wikipedia.org/wiki/Chernobyl_disaster_effects#cite_note-55.
That cited article reads, "WHO also estimates there may be up to 9,000 excess cancer deaths due to Chernobyl among the people who worked on the clean-up operations, evacuees and residents of the highly and lower-contaminated regions in Belarus, the Russian Federation and Ukraine." [1]
Stephen David Williams ( talk) 00:14, 31 July 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
You give numbers: “Total atmospheric release is estimated at 5200 PBq.” It means: 5200 PBq = 5.2 EBq = 5.2×1018 Bq = 140 MCi. In Russian version “Total atmospheric release is estimated at 14×1018 Bq.” It means: 14×1018 Bq = 14000 PBq = 14 Ebq = 380 MCi. In Russia these numbers are always in test and were checked many times. Your references [96, 97] about Fukushima. It seems like you give us understated numbers. Please correct. 05:37, 22 October 2012 (UTC) — Preceding unsigned comment added by 96.49.162.191 ( talk)
Removed All-caps comment related to Fukushima disaster at beginning of page. Comment removed for emotional opinion that has no place in an encyclopedic entry. Full figures comparing Chernobyl and Fukushima are dodgy at best given the full repercussions of the Fukushima disaster are still not fully known. 63.88.82.120 ( talk) 20:12, 12 October 2012 (UTC)Yardeditor
I didn't see it in the archives—though I'll easily admit I only went up through 2011, since the link in question was posted in October 2011—but I was wondering if this following link is relevant:
It's a video posted on the CIA's official YouTube page covering which apparently is the CIA's official video briefing of the disaster to Reagan, which apparently was declassified on or by November 2nd, 2011.
Now I personally think it may be relevant to the article, but, well, I'm not a regular Wikipedian, plus it says "No More Links", so I'll let someone else make the decision. If not a link, then a reference? — Nick15 ( talk) 02:32, 24 October 2012 (UTC)
In Chernobyl disaster#Health of plant workers and local people the following unreferenced statement appears:
This is a non-sequitur, as the WHO report was published in 2006, 20 years after the accident, which allows plenty of time for radiation-caused cancer fatalities. The word "thus" is clearly inappropriate, and gives me no confidence that the remainder of that sentence isn't simply an assumption based on some theory about latency periods. Perhaps it should just be removed, as it's remained unsourced for nearly a year and a half. Cheers, Fuzzypeg ★ 12:05, 30 October 2012 (UTC)
This claims to be "Contributions of the various isotopes to the (atmospheric) dose in the contaminated area soon after the accident". Is this really based on continuous measurements over 27 years, and were all these isotopes really present in these (relative) concentrations in the "contaminated area"? Including gases that readily disperse? And what is the "contaminated area": Chernobyl? Europe? To my understanding, data for the first several days at least was very limited, and included only simple radiation levels measured at a few locations, mostly close to the reactor itself.
Is this, then, simply a projection of expected isotopic decay based on assumptions about what isotopes made up the initial release? If so, it should be labelled as such, and not refer to any particular "area", or to being "atmospheric". And of course the phrase "soon after the accident" hardly applies to a graph with a logarithmic time scale stretching into decades. The file details in Wikimedia Commons are extremely vague about what the data really represents, how it was derived and what assumptions are made. If someone knows what this graph is about, please update the caption (and its file details). Otherwise, perhaps it should be removed from the article? Cheers, Fuzzypeg ★ 08:47, 30 October 2012 (UTC)
I believe this graph reflects the theoretical activity of all the fission products as they would appear in reactor fuel after shutdown assuming none were lost. Lesser reactor accidents (e.g., SL-1, Fukushima) primarily lost their more volatile and mobile elements (noble gases, iodine, etc) so this graph would not apply to those sites.
This graph is somewhat more applicable to Chernobyl because it was such an extreme case; a powerful explosion literally ejected much of the core into the environment. But you are still correct that the chart is theoretical, not an actual set of measurements.
I have read that Cs-137 now accounts for nearly all of the radioactivity now observed near the site, just as it does on Bikini Atoll where weapons were tested in the 1950s, but I would want to find an actual source before putting this in. Karn ( talk) 04:54, 27 February 2013 (UTC)
Hi all. I'm aware I've just been adding to this article, and probably I'll continue to add more. Yet the article is really too big. It's just over 150K, which according to WP:SIZERULE means it's way over size, and even I have difficulty navigating it. I suggest the following sub-articles be created:
It's possible that some other sub-articles could be created, or material in existing sub-articles could be rearranged, but let's not bite off more than we can chew, eh? We'll cross that bridge if/when we come to it. Any help/suggestions appreciated. Cheers, Fuzzypeg ★ 15:00, 30 October 2012 (UTC)
In this section, there are two paragraphs:
First of all, those two paragraphs contradict each other, since first paragraph says second explosion was runaway criticality, and second paragraph states other causes for the explosion.
Furthermore, reference 36 clearly states: "This result is matched up to a total reactor power of 3,200 MWt. However this estimate is not comparable with the actual explosion scale estimated as 10t TNT." Therefore, the reference itself says that the presumed runaway criticality did not cause the explosion.
Therefore, first paragraph should be removed, as it is not supported by it's own reference, and it is contradicted by the following paragraph.
-- 188.129.117.52 ( talk) 17:56, 29 December 2012 (UTC)
I don't see the contradiction between the paragraphs. The second paragraph gives the other hypotheses besides the nuclear excursion hypothesis that was ultimately accepted. That said, "runaway criticality" is not a very precise term, and "prompt criticality" is probably a better choice. That's a very rapid (time constant of milliseconds) exponential growth in reactor power when the chain reaction is maintained by prompt neutrons alone. Bombs and some special research reactors use prompt criticality; power plants normally do not.
Regarding the energy releases, I can't see the entire reference but I read the abstract and first two pages as saying that a large power spike did occur (the Xe-133/Xe-133m ratio was smaller than it would be for a power reactor, but not as small as it would be for a bomb) but that if the entire core had been involved the energy release would have been vastly larger than actually observed (i.e., 100-1000 kT, that of a good-sized nuclear weapon). So they concluded that the energy spike was generated in a small part (0.01%-0.1%) of the reactor core. Karn ( talk) 04:36, 27 February 2013 (UTC)
Several radiation rates and doses are given in secondary units that make no sense. For example, 5.6 roentgens (rads?)/sec is given as 1.4 milliamperes per kilogram. The actual dimensions of radiation dose are energy per unit mass, with 1 rad being 10 millijoules/kg. A dose rate would therefore have units of power per unit mass, so 5.6 rad/sec is equal to 56 milliwatts/kg. I'm making this change. Karn ( talk) 04:11, 27 February 2013 (UTC)
Never mind, the roentgen does have units of charge per unit mass. (Learn something every day...) The SI units of radiation exposure have units of energy per mass, with the gray being used for matter and the sievert used for biological tissue with a dimensionless "quality factor" depending on the type of radiation relating the two. If original sources giving doses and dose rates in rad or preferably grays can be found, they should replace the long-obsolete and never-standard roentgen. Karn ( talk) 04:19, 27 February 2013 (UTC) By: Seth Griner — Preceding unsigned comment added by 75.16.200.172 ( talk) 23:17, 6 March 2013 (UTC)
In the first paragraph/point, it contains the sentence: "Chernobyl's RBMK reactor, however, used solid graphite as a neutron moderator to slow down the neutrons, and the water in it, on the contrary, acts like a harmful neutron absorber." And the second paragraph say: "The upper part of the rod, the truly functional part that absorbs the neutrons and thereby halts the reaction, was made of boron carbide."
It's not very clear to me in the first paragraph why the absorptions is harmful in that particular case. Is it because graphite (and the water, too?) only partly absorbs neutrons as opposed to absorbing them significantly more when the boron carbide sections are inserted?
122.59.225.50 ( talk) 02:34, 11 March 2013 (UTC)
There seems to be a lot of controversy about whether graphite was the fuel for the fire in the reactor, or perhaps whether there was any real fire in the reactor going on at all, as opposed to simply a meltdown of red-to-yellow hot materials. There are several places in this article where a graphite fire is mentioned, but in only one place was it sourced, in a quote from Medvedev's book. It seems like the sort of "assumed" comment that one would make; after all, graphite is just compressed coal; one would think carbon burns, and pure carbon burns most easily. For Medvedev's part, he is a biologist, and that sort of burning might seem like an obvious assumption to a biologist.
This has proven not to be the case. It has been shown that the purer the carbon the better graphite resists fire, and that in fact it is extremely refractory in the purity required for reactors. There are plenty of citations for it to be easily able to resist burning at 1000-1800 degrees C, although it does seem to slowly erode and either sublimate or oxidize a small amount at a time, nothing near to being able to sustain an active fire. In many papers mention is made of heating it to 4-6000 degrees C without burning, far above any temperature that a reactor core, in meltdown or otherwise, could reach. Some have suggested that it might oxidize in the presence of very high heat and steam, like zirconium, reducing the water to hydrogen gas.
Are there any citations which support the possibility of a graphite fire in the reactor? The Sellafield/Windscale fire accounts seem to avoid graphite fires, more heavily leaning on uranium fire, which is certainly supportable. SkoreKeep ( talk) 22:09, 20 March 2013 (UTC)
Article says:
"As the reactor power output dropped further, to approximately 500 MW, Toptunov mistakenly inserted the control rods too far—the exact circumstances leading to this are unknown because both Akimov and Toptunov were killed during the later explosion."
Alexander Akimov article says:
"Akimov died two weeks after the accident due to Acute Radiation Syndrome, also known as radiation poisoning, at the age of 33."
Did he die in the explosion or did he die two weeks later? - Lapinmies 11:46, 2 April 2013 (UTC)
Hello! This is a note to let the editors of this article know that File:Chernobyl radiation map 1996.svg will be appearing as picture of the day on April 26, 2013. You can view and edit the POTD blurb at Template:POTD/2013-04-26. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Crisco 1492 ( talk) 22:50, 10 April 2013 (UTC)
I've added English subtitles for "Pripyat evacuation broadcast" soundfile by choosing CC-->Add subtitles-->en-English-->GO from the article's page. But subtitles added on the file's page ( http://en.wikipedia.org/wiki/File:Pripyat_1986.ogg). And soundfile's box at the article's page still says "No text tracks available". However, when I choose CC-->Add subtitles-->en-English-->GO from the article's page again it offers me to edit the subtitles I added before. Can anyone help? -- V001rus ( talk) 07:58, 18 April 2013 (UTC)
A recent edit (Remus Octavian Mocanu, 28 April) includes the following passage (my emphasis):
The bolded part looks very POV, and the whole section reads like an essay. Iapetus ( talk) 12:17, 30 April 2013 (UTC)
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Please move the following from the "Steam Explosion Risk" section to another section. While this information is interesting and pertains to the topic of the Chernobyl disaster as a whole, it does not contribute to explaining the steam explosion risk or how it was mitigated. It should also be noted that the sentences could be changed to read along the lines of "Hydrogen peroxide (H2O2) was generated during the accident by conversion of the Bubbler pool water, which was likely caused by intense the alpha radiation. This is proved by the presence of studtite and metastudtite in the Chernobyl lavas. These are the only minerals that contain peroxide.[65][66][67][68]" Note my intent here is only to combine what appears to be content from two separate people in a way that provides the same information but no longer looks as if it was written by multiple people at different times. The original section is contained below:
"It is likely that intense alpha radiation hydrolyzed the water, generating a low-pH hydrogen peroxide (H2O2) solution akin to an oxidizing acid.[65] Conversion of bubbler pool water to H2O2 is confirmed by the presence in the Chernobyl lavas of studtite and metastudtite,[66][67] the only minerals that contain peroxide.[68]"
RayEPreston ( talk) 23:15, 28 April 2013 (UTC) RayEPreston ( talk) 23:15, 28 April 2013 (UTC)
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Please change USSSR to USSR in "Deaths due to radiation exposure" under "Human impact." 71.158.169.111 ( talk) 06:18, 2 May 2013 (UTC)
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Under the Effects section of the article: the image description is incorrect. It is not a "Puppy with Dipygus..." it is a piglet. The Russian text in the image says so: http://upload.wikimedia.org/wikipedia/commons/0/02/Kiev-UkrainianNationalChernobylMuseum_15.jpg Msurkis ( talk) 08:53, 24 May 2013 (UTC)
Currently text states:
"A bigger problem was a flawed graphite-tip control rod design, which initially displaced neutron-absorbing coolant with moderating graphite before introducing replacement neutron-absorbing boron material to slow the reaction. As a result, the SCRAM actually increased the reaction rate in the upper half of the core as the tips displaced water. This behavior was known after a shutdown of another RBMK reactor induced an initial power spike, but as the SCRAM of that reactor was successful, the information was not widely disseminated.
A few seconds after the start of the SCRAM, the graphite rod tips entered the fuel pile." ...
This is partially incorrect. Russian wiki has a more correct explanation. I propose the following edition instead of the above fragment:
"A bigger problem was a flawed graphite-tip control rod design. In RBMK reactors, control rods occupy some of nearly 2000 vertical channels, most other channels contain fuel rods. Cooling water is pumped through each channel. A control rod has an absorbing section 7 meters long (same as channel height). When the rod is fully withdrawn, this section is situated above the core. If control rod would have nothing below this section, in this position its channel would be completely filled by water. Since in RBMK water isn't the primary moderating material (graphite is), presence of this water has slightly detrimental effect of absorbing some neutrons. To prevent this, RBMK control rods have another section, made from graphite, below the absorbing section. When the rod is fully withdrawn, this graphite-tip section is positioned in the channel where it displaces some water and improves neutron economy.
The flaw is that the graphite-tip section is not 7 meters long, but only about 5 meters long. When fully withdrawn control rod starts moving down, in the lower 2 meters of its channel the graphite tip displaces water, which increases power generation in this part of the core, instead of decreasing it.
When AZ-5 button was pressed, almost all control rods started moving down, thus the SCRAM actually increased the reaction rate in the lower part of the core as the tips displaced water. This behavior was known after a shutdown of another RBMK reactor induced an initial power spike, but as the SCRAM of that reactor was successful, the information was not widely disseminated.
A few seconds after the start of the SCRAM, the graphite rod tips displaced water in the lower part of the core."
Since the article is protected, I can't modify it. Can someone do this for me? Thanks. 85.71.196.161 ( talk) 01:03, 8 June 2013 (UTC)
Chernobyl abortions: leads one to assume that the abortions happened in chernobyl, or that chernobyl itself induced the abortions, it is therefore a misleading title, as it was the irrational phobia present in some parts of the general public, which actually precipitated people to seek abortions. Hysteria abortions, are what is being discussed in the journals, as radiophobia abortions falsely suggests that the phobia was so strong it spontaneously triggered stress responses that triggered involuntary abortions, which again, is not the case, people elected to get the procedure, out of fear.
Do you have another suggestion?
Boundarylayer ( talk) 11:31, 8 June 2013 (UTC)
Acording to this, and several other sources I found the last restrictions on livestock in the UK were lifited in 2012. http://www.telegraph.co.uk/news/uknews/9156393/Chernobyl-sheep-movement-restrictions-finally-lifted.html — Preceding unsigned comment added by 216.8.128.54 ( talk) 22:49, 13 July 2013 (UTC)
The radiation level cannot fall to zero, though it can approach it ever more closely. -- John ( talk) 05:36, 28 May 2013 (UTC)
I recently edited the article to show that there are two types of casuality estimates, those that are peer-reviewed and those that are not. However this was reverted by User:John
Here's the edit [2]
Thirty one deaths are directly attributed to the accident, all among the reactor staff and emergency workers. [1] An UNSCEAR report places the total confirmed deaths from radiation at 64 as of 2008. The Chernobyl Forum predicted eventual death toll could reach 4,000 among those exposed to the highest levels of radiation (200,000 emergency workers, 116,000 evacuees and 270,000 residents of the most contaminated areas); this figure is the total casual death toll, including some 50 emergency workers who died soon after the accident from acute radiation syndrome, nine children who have died of thyroid cancer and a future predicted total of 3940 deaths from radiation-induced cancer and leukemia. [2]
Based upon further extrapolations of the controversial Linear no-threshold hypothesis of radiation induced damage, down to zero, the Union of Concerned Scientists estimates that, among the hundreds of millions of people living in broader geographical areas, there will be 50,000 excess cancer cases resulting in 25,000 excess cancer deaths. [3] For this broader group, the 2006 TORCH report predicts 30,000 to 60,000 excess cancer deaths, [4]
In terms of non-peer reviewed publications, two affiliated with the controversial anti-nuclear advocacy group Greenpeace, have been released, one of which reports the figure at 200,000 or more. [5] The Russian founder of that regions chapter of Greenpeace, also authored a book titled Chernobyl:Consequences of the Catastrophe..., which concludes that among the billions of people worldwide who were exposed to radioactive contamination from the disaster, nearly a million premature cancer deaths occurred between 1986 and 2004. [6]
The book however has failed the peer review process, [7] [8] five reviews were published in the academic press, with four of them considering the book severely flawed and contradictory, and one praising it while noting some shortcomings. The review by M. I. Balonov published by the New York Academy of Sciences concludes that the value of the report is negative, because it has very little scientific merit while being highly misleading to the lay reader. It also characterized the estimate of nearly a million deaths as more in the realm of science fiction than science. [9]
Reported thus far are 237 cases of acute radiation sickness and 31 deaths.
balonov
was invoked but never defined (see the
help page).Boundarylayer ( talk) 23:31, 27 May 2013 (UTC)
Section 8.3 The Exclusion Zone has a number of errors. I made a few basic changes but don't feel comfortable tackling all of them.
An area extending 30 kilometres (19 mi) in all directions from the plant is known as the "zone of alienation". - I made corrections in the article in this sentence. It is largely uninhabited, except for a few residents who have refused to leave. - The number of samosels (resettlers) was 314 in 2009. I don't have more recent data so I'd say "about 300"
The area has largely reverted to forest, and has been overrun by wildlife because of a lack of competition with humans for space and resources. - overrun is an overstatement. Wildlife has increased overall, but many species populations are not healthy. See Mousseau et al: http://cricket.biol.sc.edu/chernobyl/Chernobyl_Research_Initiative/Introduction.html
Even today, radiation levels are so high that the workers responsible for rebuilding the sarcophagus are only allowed to work five hours a day for one month before taking 15 days of rest. - This is completely wrong. The radiation levels vary more than 1000-fold across the Exclusion Zone. Some areas have less radiation than outside the Zone. The text conflates the levels in the Zone and at the plant, where they are higher. Workers in the Zone historically mostly worked 15 days on, 15 off, but in the past 5 years there has been a shift to 4 on, 3 off. Lastly, no one is rebuilding the sarcophagus. There is a New Safe Confinement superstructure which is currently being built over the Sarcophagus.
Ukrainian officials estimate the area will not be safe for human life again for another 20,000 years.[56] - I have no information here In 2011 Ukraine opened up the sealed zone around the Chernobyl reactor to tourists who wish to learn more about the tragedy that occurred in 1986. - No, the zone has been open since at least 2005 maybe longer, it's just that in 2011 the Ukrainian National government recognized this as a money-making opportunity and started increasing publicity.
— Preceding unsigned comment added by Mfrphoto ( talk • contribs) 01:43, 6 September 2013 (UTC)
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The phrase "The Russian founder of that regions chapter of " in the overview section should have an apostrophe in "regions" so that it says "region's", because the plural "regions" is incorrect. The possessive "region's" is correct. Benbelly ( talk) 19:22, 4 December 2013 (UTC)
On 12 February 2013 a 600 m2 (6,500 sq ft) section of the roof of the turbine-building — Preceding unsigned comment added by 114.198.5.150 ( talk) 04:23, 5 December 2013 (UTC)
"Reactor 4 at Chernobyl consisted of about 1,600 individual fuel channels; each required a coolant flow of 28 metric tons (28,000 liters or 7,400 U.S. gallons) per hour" (section Accident) had an clarification needed tag with it, with the reason not possible, each 1600 fuel channel requires 28 tons of water an hour? please check source
I don't have acces to the source either (book), but although it seems like a huge amount, a quick calculation shows it's not unreasonable. 3200 MW power production means that amount has to be absorbed by the water, so these 1600 * 28000 litres of water would warm up by:
3,2 * 10^9 W * 3600 s / (4184 J/kg K * 1600 * 28000 L * 1 kg/L) = 61 K increase in warmth for the water.
This seems likely to me, so I have removed the tag.
EmilTyf (
talk)
16:38, 12 December 2013 (UTC)
Yes. It amounts to just less than 8 liters per second per fuel rod, which has a good feel. The water pumps in gigawatt-class water-cooled reactors are simply huge. A reactor document ( http://www4.ncsu.edu/~doster/NE405/Manuals/PWR_Manual.pdf) rates the Westinghouse pumps at 7000 HP, 100,000 gpm, (that's 3000 liters/sec) and there's 4 of them in an 1100 megawatt reactor. SkoreKeep ( talk) 08:54, 18 February 2014 (UTC)
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In the Evacuation Developments section, the sentence "A state commission was set up the same day (26 April) and tasked with investigating the accident." is preceded by a sentence referencing events on the 28th of April. The sentence should be changed to reflect that the commission was set up on the day of the accident; not the day of the announcement. "A state commission was set up on the same day as the accident and tasked with the investigation." 192.0.133.61 ( talk) 00:17, 3 March 2014 (UTC)
It's not clear from this sentence whether it was Ukraine or the nuclear plant "under the direct jurisdiction of the central authorities" of Soviet Union:
"[...] was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine (then officially the Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the Soviet Union."
Dchestnykh ( talk) 07:31, 26 April 2014 (UTC)
In terms of total radiation released, Fukushima is the worst nuclear disaster. Fukushima Daichi stored much more nuclear material onsite since it is a much larger complex than Chernobyl. Fukushima is the 10th largest nculear facility in the world, and Chernobyl did not even rank in the top 100. It is estimated that 80% of the entire fuel supply was lost to the environment according to independent studies. Furthermore, the highest radiation readings ever taken occurred in the area surrounding Fukushima. I am confused as to how Chernobyl could be considered the worst. Very dubious. — Preceding unsigned comment added by 76.240.172.212 ( talk) 00:22, 1 September 2014 (UTC)
18 billion rubles is 500 million US today, suggest adding to opening to put into perspective for wider western audience. — Preceding unsigned comment added by 203.47.198.254 ( talk) 05:26, 14 May 2014 (UTC)
Under overview, the statement "...several hundred million cancer cases are expected from other causes." - with no further quote from the citation is very misleading. If every person in the entire region through 2065 contracted cancer, that would still be a stretch?
The source is of course reputable and academic but it goes on to say immediately afterward which is not part of the current edit, "Although these estimates are subject to considerable uncertainty, they provide an indication of the order of magnitude of the possible impact of the Chernobyl accident." Trep26 ( talk) 03:44, 26 February 2014 (UTC)
→I don't mean to diminish how tragic this was and still is... just saying "several hundred million" sounds unreal/sensationalist and it doesn't seem possible. Trep26 ( talk) 04:04, 26 February 2014 (UTC)
The United Nations Scientific Committee on the Effects of Atomic Radiation, reports that more than 6,000 individuals, who were children or adolescents at the time they were exposed as a result of the accident, have contracted thyroid cancer since 1986. More cases are expected in the coming decades, and notwithstanding "the influence of enhanced screening regimes, many of those cancers were most likely caused by radiation exposures shortly after the accident". However: "There is no scientific evidence of increases in overall cancer incidence or mortality rates or in rates of non-malignant disorders that could be related to radiation exposure. The incidence of leukaemia in the general population, one of the main concerns owing to the shorter time expected between exposure and its occurrence compared with solid cancers, does not appear to be elevated. Although those most highly exposed individuals are at an increased risk of radiation-associated effects, the great majority of the population is not likely to experience serious health consequences as a result of radiation from the Chernobyl accident.". See: http://www.unscear.org/unscear/en/chernobyl.html — Preceding unsigned comment added by IanDM 005 ( talk • contribs) 23:43, 21 September 2014 (UTC)
According to two 2012 movies, natural wildlife was able to recover in the restriction zone. Cancer does not develop in fast reproducing short living animals. Misfit mutations were short lived, due to regular evolutionary forces, and normal populations appear to have outlived any abnormalities. No long standing effects have been found in fishing birds which eat fish with heavily contaminated radioactive bones.
I think all this is worthy of mention in a separate section. פשוט pashute ♫ ( talk) 09:09, 29 September 2014 (UTC)
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32 People Died Amediatly Benzy707 ( talk) 09:52, 25 November 2014 (UTC)
Not done Please see
Deaths due to the Chernobyl disaster -
Arjayay (
talk)
09:56, 25 November 2014 (UTC)
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Please remove: Germany has "banned wild game meat because of contamination linked to radioactive mushrooms".[128]
Reasons: Reference link [128] is dead and the sentence is easily misunderstood. Only wild boar meat showing radiation levels of more than 600 becquerel/kg is not permitted to be sold. The hunter is free to consume it himself, however. [1] The above sentence makes it sound like all wild game meat in Germany is contaminated and banned, which is not correct.
[1] http://www.forsten.sachsen.de/wald/2886.htm#article2906 (should be translatable by google) Breakareas ( talk) 20:28, 1 December 2014 (UTC)
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In the first section, 18 billion rubles is not worth 18 billion usd. And the syntax is wrong. My best guess is US$6071589000 according to http://rub.fx-exchange.com/usd/1986-exchange-rates.html 218.214.108.128 ( talk) 03:23, 22 December 2014 (UTC)
In the section "Effects", there is a picture of a disformed animal, and it is said to be a piglet. However, in the Norwegian (bokmål, not nynorsk) article, it is said to be a hundevalp, which apparently means (dog)puppy (I do not speak Norwegian, but it is very similar to Swedish, and dogpuppet is hundvalp in Swedish). So my question is: which of these is true? K9re11 ( talk) 13:25, 20 April 2015 (UTC)
I rarely comment on even the most politically biased articles I see - since it has proven to be more than pointless,
however since today is 26.04 and these events did happen precisely 29 years ago - I would like to make one comment, if Wikipedia community will react to it in any way or not is up to you.
I find it ridiculous that 29 years later, the official politically biased story is still published even in "politically unbiased" places like this one (Wikipedia article).
For example the statement that: "The reactor was in an unstable configuration that was clearly outside the safe operating envelope established by the designers." is the same false statement which was used to place all of the blame on the operators and engineers of the plant - the same people who Knowingly gave their lives to try to contain the disaster.
It was a statement created in order to clear all of the responsibility from the constructors and the local regulators at the time... however - the truth is, that as strange and mind boggling the actions of the people in the control room may look today, they were operating the reactor exactly WITHIN the safety limits and margins according to the instructions at the time. The fact that these instructions were not adequate is completely different story. But they were written by the constructors of the reactor - there is plenty of references out there (including in the list of references of the main article) which include the very same safety instructions used at the time. It is easy for us today to say that these people broke the rules - today we know a lot more about these reactors, however the truth is that even if their actions seem to be not 100% understandable today, they did not break any rules. The rules at the time were inadequate. Only AFTER the accident the rules and safety margin estimations were updated, even the design of the RBMK reactors was updated in order to make them inherently safe - but that happened AFTER not before the accident.
The article also quotes Valery Legasov stating "It was like airplane pilots experimenting with the engines in flight." The very same Legasov, who comitted a suicide 2 years later, and who did leave a tape proving that the official reports have been modified in order to clear the responsibility from the constructors of the reactor.
Naturally the discussion about who did what and why in this accident can last till the end of time - and this really is not the point of my comment (which became obnoxiously long). The point really is that this statements do not belong in a unbiased encyclopedic article. Or if they MUST be there, they should be presented on even ground with all other analysis published in the later years. Stating that this was the truth and the only truth about this accident is simply wrong and in my opinion well under the level of Wikipedia.
Perhaps a serious and more unbiased rewriting of this article, combined with proper cleanup might help the people who use this article as a learning tool. Sailor MikeFIN ( talk) 19:35, 26 April 2015 (UTC)
There are issues with the identification and links to an OECD technical report on the accident: Chernobyl, Ten Years On, Assessment of Radiological and Health Impact. Original dated 1995. Then updated in 2002. Both reports can be accessed from OECD website, the 2002 version content is posted at least in part on the OECD website. The 1995 report here: https://www.oecd-nea.org/rp/chernobyl/chernobyl-1995.pdf. The 2002 update here: https://www.oecd-nea.org/rp/reports/2003/nea3508-chernobyl.pdf.
It appears that the 2002 update is being referenced in most cases, and it should be referenced as it is more current. Ref 109 should reference Ch.2 of the 2002 report. References 31, 44 and 85 should be merged and reference Ch.1 of the 2002 report.
Reference 111 appears to reference the original 1995 report, although it states it was released in 1998, and the actual link provided is a hard-to-follow link to a journal article that likely summarizes the 2002 update. The link should go directly to the 1995 report.
The text in second paragraph under Section on Radioactive Release refers to "two 1998 reports", with two links provided. One link is to the above 1995 OCED report. The other reference 109 links to a citation database, and the citation is actually for a 1989 Health Physics article. The article is an appropriate reference, but is inconsistent with the text that implies this is an OSTI 1998 report. If there is a 1998 OSTI report, then this link needs to be changed. Otherwise the 1989 Health Physics article is fine, but the text in the article needs to be changed.
I propose to combine and update these links, but am posting this first to explain the proposed change and in case there is some history on these links to discuss. Gierszep ( talk) 21:08, 30 May 2015 (UTC)
I don't know if "What if" scenarios are really within the scope of the article but serious estimations by credible sources of what would have been the effects of the steam explosion, had the three men not managed to open the valves, would be appreciated. Especially since one is constantly confronted with utterly sensationalist claims such as vast parts of Europe being turned into Fallout wasteland etc.
Currently the article only states that more radioactive material would have been ejected from the reactor. — Preceding unsigned comment added by 2A02:8108:1E00:1924:C108:152F:61E3:2ADA ( talk) 00:56, 6 August 2015 (UTC)
I refuse to believe that the casualty # is 31 direct. If the information is unknown than make that known.
There is another collision in same section; section: "Steam turbine tests" Statement: "The Chernobyl power plant had been in operation for _two years_ without the capability to ride through the first 60–75 seconds of a total loss of electric power" (note: _two years_) and few lines above we can read: "An initial test carried out in _1982_ showed that the excitation voltage of the turbine-generator was insufficient; it did not maintain the desired magnetic field after the turbine trip. The system was modified, and the test was repeated in 1984 but again proved unsuccessful. In 1985, the tests were attempted a third time but also yielded negative results. The test procedure was to be repeated again in 1986"
So how Chernobyl power plant had been in operation for _two years_ without the capability to ride through the first 60–75 seconds of power loss when _first_ tests was conducted FOUR years prior disaster ("An initial test carried out in _1982_") for same reasons? Calimero ( talk) 00:12, 25 November 2015 (UTC)
Answer: 26 April 1986 test is not reactor working condition test but exercise (drill) test to see what happened when plant is losing power. For reactor, "Two years" is correct, the reactor is connected to grid in 1984.
"These were the engineers Alexei Ananenko (who knew where the valves were) and Valeri Bezpalov, accompanied by a third man, Boris Baranov [...] All of them returned to the surface and according to Ananenko, their colleagues jumped for joy when they heard they had managed to open the valves. Upon emerging from the water, the three were already suffering from radiation sickness and later died."
It looks like Bespalov was still alive in 2008, There's even a photo of him here with the following tag: "Валерий Беспалов, сотрудник с 25-летним стажем, начальник смены первой очереди ЧАЭС. Лично контролирует состояние отработанного топлива в отключенном реакторе первого эторгоблока. Называет себя патриотом станции" Gyurika ( talk) 19:59, 3 May 2015 (UTC)
Beata Li Caused this event — Preceding unsigned comment added by 216.165.126.103 ( talk) 16:58, 15 May 2015 (UTC)
"there may have been several Bespalovs at Chernobyl" And what do you base this hypothesis on? Do you have any sources, that prove that there were multiple Valeriy Bezpalovs both working there in the 1980s? Gyurika ( talk) 08:22, 7 August 2015 (UTC)
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Archive 5 | ← | Archive 8 | Archive 9 | Archive 10 | Archive 11 | Archive 12 | Archive 13 |
For an accident causing release of radioisotopes, of major relevance for readers is learning the quantitative amount of radiation exposure resulting from such. As implied in WP:RSUW, reliable sources are to be favored, and undue weight should not be given to non-reputable sources by only highlighting their claims without equally highlighting the conclusions of reputable sources.
That the summary of this article highlights global consequence claims from political activist groups like Greenpeace, while questionable, is arguably acceptable as long as such is combined with also reporting at least a bit of the global exposure analysis of a more official source, the United Nations UNSCEAR. Accordingly, I have not deleted any of even the most extreme claims but have aimed to mix in a little info from a more reputable source, keeping such together in comparable highlighting.
Without that, wording of this article's summary would be providing a very misleading impression (generous to not call dishonest) to many readers, so as to make them assume only the likes of Greenpeace considered more than local exposure, not even realizing the UNSCEAR has estimated exposure over a multitude of countries in depth as seen in their vast expansive scientific reports.
Recent history:
...
Upwards of 0.3 million recovery workers received a mean dose of 150 mSv (milli-Sieverts) each in 1986.[11] The report to the General Assembly of the UN notes average exposure over the far broader entire populace of the Northern Hemisphere was 0.04 mSv in the year of the accident, and, after decrease over time, residual exposure was a global average of 0.002 mSv/yr in 2008 (separate from other sources of radiation exposure such as an average of 2.4 mSv/yr from natural sources).[11]
...
That way of organization is debatable; I would not have tried it except for his remark. In any case, though, in contrast to what I think he wanted me to do, the summary can not solely highlight the activist claims while simultaneously burying the UNSCEAR info only very many pages deep within the document. A large portion of readers would not keep reading to find it if they thought the former was an authoritative summary, not realizing the violation occurring of Wikipedia's policy on undue weight. (Just like, in almost any context, any web page from Wikipedia to unrelated sites, if looking at hit counters, typically only several percent or less of readers will click on any link for further explanation, an article as lengthy as this will have many readers just reading the summary alone; the summary should not be excessively misleading).
...
Another UN agency, UNSCEAR, has estimated a global collective dose of radiation exposure from the accident "equivalent on average to 21 additional days of world exposure to natural background radiation."[10]
...
The quoted part is a short direct quote, from the UNSCEAR, via an IAEA article. The UNSCEAR report itself estimates exposure, for the total worldwide figure which is higher than local populations alone, amounted to 200,000 man-Sv in the first year and would be a total of around 600,000 man-Sv as a dose commitment. (The dose commitment is that including part received over decades, some yet to be received in the future).
A reader may not know exactly how much the "equivalent on average to 21 additional days of world exposure to natural background radiation" may mean in excess cancer mortality (and there is even debate in the scientific world over such as the LNT model versus alternatives), but it is still far more knowledge than the assumptions of many readers if carefully kept uninformed. (For instance, surveys have shown a huge percentage of the general public does not know any natural radioactivity even exists and thus would presumably assume manmade accidents like Chernobyl caused to the average person in the world the equivalent of decades of exposure to average background radiation; Chernobyl was a terrible accident, the worst by far, something to learn from and avoid, but giving impressions orders-of-magnitude off is not the proper purpose of an encyclopedia).
One will see if that addition gets deleted by the same user, by Apostle12, under a new creative excuse. If so, that fourth revert in a row, each time doing nothing but deleting everything I add, would be a violation of WP:3RR in spirit. While in this case not all within a 24 hour period, Wikipedia's three-revert rule discussion notes how it does not in practice have to be within literally a 24 hour period alone to be unacceptable.
Sokavik ( talk) 21:15, 17 May 2012 (UTC)
Regarding your monetary analogy, global GDP (the total sum of everyone's income) would be a relevant figure, such as knowing if a particular economic event changed global GDP by 0.0001% or by 40% or any other number, for at least some idea of the order of magnitude.
Getting back to the matter of the sum of radiation doses:
As one example, under the common LNT model (linear no-threshold), the amount of cancer mortality would be proportional to the number of people exposed times their average dose each, thus proportional to the collective dose. In the LNT model, each person-Sievert would be approximately comparable in the chance of a cancer death it statistically corresponds to, whether a given person-Sievert comes from one group of 100 people receiving 10 mSv each or another group of 1000 people receiving 1 mSv each.
The LNT model is debatable, but, in any case, having some quantitative idea of average public radiation exposure is better than having no idea even to within orders of magnitude.
As an example of a much different figure, if a far lesser thought-experiment accident (not Chernobyl) caused 0.06 man-Sv instead of 600000 man-Sv collective dose, a conclusion could be made practically even from knowing that fact alone that the thought-experiment accident was not likely to have caused many cancer deaths (whether it was 0.06 mSv to one person or 0.01 mSv to six people or other examples), since such could be compared to the around 160+,000,000 man-Sv received per decade by the world's population from natural background radiation (which itself varies).
For instance, if one source of radiation exposure causes X man-Sv effective dose; another causes 1000 * X man-Sv dose; and one knows the observed cancer mortality caused by the latter could not be more than Y as an upper limit for a variety of reasons; then one would have at least a perspective if reading a claim by questionable sources that the former caused orders of magnitude more than 1/1000th of Y number of cancer deaths.
More than any other source, the UNSCEAR does have tables of radiation exposure estimates by country and region. For instance, the 8.8 PBq of Cs-137 deposited in Central Europe caused an estimated collective dose of 49000 man-Sv in the first year and 166000 man-Sv total dose commitment over decades, with the population of Central Europe (178 million at the time) receiving on the order of around 0.9 mSv each on average from such. The corresponding figure for West Europe was around 0.15 mSv each.
I could list the countries counted as in each region or figures for smaller regions. However, I won't get too much more verbose here.
For some basis of comparison, lifetime exposure to natural radiation varies by hundreds of mSv between many countries, even as country-wide averages, multiple mSv/yr
http://upload.wikimedia.org/wikipedia/commons/5/55/Natural_Radiation_Atlas_of_Europe.jpg
Anyway, the article states global effect (mortality) claims from activist groups. Aside from any debate over sources, it is correct to include global figures (not just local alone) ... and that applies to UNSCEAR as much.
With that said, personally I would be totally fine with highlighting that average global exposure is different from local averages, a reminder in case not already obvious. Such is exactly what I did in my first 2-sentence version of the addition, before trying this more concise 1-sentence version. The original was:
...
Upwards of 0.3 million recovery workers received a mean dose of 150 mSv (milli-Sieverts) each in 1986.[11] The report to the General Assembly of the UN notes average exposure over the far broader entire populace of the Northern Hemisphere was 0.04 mSv in the year of the accident, and, after decrease over time, residual exposure was a global average of 0.002 mSv/yr in 2008 (separate from other sources of radiation exposure such as an average of 2.4 mSv/yr from natural sources).[11]
...
For instance, one could write:
...
Another UN agency, UNSCEAR, has estimated a global collective dose of radiation exposure from the accident "equivalent on average to 21 additional days of world exposure to natural background radiation"; individual doses were far higher than the global mean amongst those most exposed, including 300000 local recovery workers who averaged an effective dose equivalent to 60 years of extra background radiation exposure each.[10]
...
The current version of the article at the moment I am writing this is also okay as far as I am concerned. I just wrote in Talk to prepare for a likely fourth deletion of my edit by the other guy, after the prior three in a row. While I suspect it might happen in the next few hours, if it doesn't, then matters are good.
Sokavik ( talk) 00:39, 18 May 2012 (UTC)
its nuclear bombing not atomic bombing. please correct your physics error — Preceding unsigned comment added by 96.2.38.144 ( talk) 19:18, 24 May 2012 (UTC)
The top paragraph ends: The battle to contain the contamination and avert a greater catastrophe ultimately involved over 500,000 workers and cost an estimated 18 billion rubles, crippling the Soviet economy.
Does anyone know enough about all of that to come up with a comparison amount? Or has it been calculated somewhere by some experts? — Mwr0 ( talk) 15:45, 4 June 2012 (UTC)
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The 'total death toll' number given in the article is misleading. While it references the WHO article on Chernobyl (#14) the actual number in the article doesn't match to that source data. What's more, even in the source data the number given is very clearly listed as a 'guess' which is not terribly well supported. While it is an educated guess, it is a guess nonetheless and could be wrong and indeed very wrong. As such the number given in the article is misleading.
The actual KNOWN FACTS (positive as opposed to speculative) on the Chernobyl disaster death toll are 31 workers and firemen in the intitial event. Two of those died from the explosion proper, and the others from Acute Radiation Sickness in the following weeks.
In addition there was an increase in thyroid cancers in the region directly attributed to radioactive iodine exposure, primarily in children. Roughly 9000 cases were recorded, however the survival rate of was in the vicinity of 99%. So probably in the vicinity of 90 additional deaths that can be reliably attributed to radiation exposure. Interestingly, the fear of radiation exposure almost certainly contributed to the high survival and detection rate as everyone was so sensitive about the matter.
The claim of 'thousands' of deaths, however, is problematic. Yes, since 1986 lots of people originally from the region have died of cancer. However in a 25 year period sections of any population will expire from cancer and the population in question is known to have higher than global average rates of tobacco and alcohol use as well as poor nutrition. Reputable studies, when not speaking apocryphally, make it clear that the death toll and cancer rate amongst those thousands exposed at the time of the disaster is no higher than control groups without exposure from similar regions/cultures.
In other words, while some of those cancers may have been as s result of Chernobyl exposure, there is no way to prove how many, if any and the overall number of people suffering from these diseases is no higher than those in non exposed groups. Or, put more simply, if you were living in Pripyat in 1986 at the time of the accident and died in 2006 from lung cancer did that cancer come from reactor exposure or chain smoking cigarettes your entire life? Given that no reputable study that I have been able to find shows an increase cancer rate over non exposed similar populations, the actual provable, reliable and meaningful death toll as a result of radiation exposure and other direct disaster related effects (such as being blown up) should really be in the vicinity of around 130 people.
All that said, the SOCIAL impact of the disaster, the relocation and the like has been huge and caused all manner of psychological issues etc. but those effects have not been shown to be any more severe than similar populations that survive earthquakes, tsunamis and the like. The disaster was still a disaster, but the social consequences were far more significant than radiation exposure.
Feel free to check sources yourself, but the number at the wiki page is misleading and anyone quoting it without referring to the original source will be quoting a number not supported by actual research. A more accurate statement would be "the scientifically provable death toll is somewhere between 120 and 150 including cancer sufferers from radioactive iodine exposure. While there were many fears of increased health issues due to radiation exposure, scientific studies have not shown a statistically higher occurance of these maladies in the exposed population in comparison to similar populations which were not exposed."
That leaves people quoting a much more accurate PROVABLE number rather than the entirely unproven number of 3500 (ish) which has come down greatly from originally listed estimates of tens to hundreds of thousands which were completely out to lunch.
In short, there has been 25 years of fear mongering about the Chernobyl disaster. Now that we have real numbers and actual studies on the true medical impact, it would make sense to shift our focus away from the terrifying 'N' word and toward the tremendous social and economic damage caused by the meltdown of reactor #4. Those are the real issues and it's about time we focussed on those.
64.4.88.2 (
talk)
15:34, 6 July 2012 (UTC)
The page states "Toptunov mistakenly inserted the control rods too far - the exact circumstances leading to this are unknown because both Akimov and Toptunov were killed during the later explosion." however, Alexander Akimov states that Akimov survived the initial explosions and died two weeks later from radiation poisoning. Which is correct? — Preceding unsigned comment added by 2.98.162.171 ( talk) 16:22, 14 July 2012 (UTC)
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In the Human impact section can we edit the sentence "The predicted 4000 deaths from the UN is based on the Linear no-threshold model (LNT), which assumes that the damage inflicted by radiation at low doses is directly proportional to the equivalent dose." to say 9000 instead of 4000?
I suggest the start of the sentence should read "The WHO's prediction of 9000 deaths in surrounding countries [citation as below] is based on the linear no-threshold model (LNT), which ..."
This is because the Chernobyl_disaster_effects article states that the UN agency (WHO) has revised its number of cancer's to 9000, citing http://en.wikipedia.org/wiki/Chernobyl_disaster_effects#cite_note-55.
That cited article reads, "WHO also estimates there may be up to 9,000 excess cancer deaths due to Chernobyl among the people who worked on the clean-up operations, evacuees and residents of the highly and lower-contaminated regions in Belarus, the Russian Federation and Ukraine." [1]
Stephen David Williams ( talk) 00:14, 31 July 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
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Footnote 73, directing to the "Expert report to the IAEA on the Chernobyl accident", starts with "(in Belarusian)". This should be changed into "(in Russian)". 131.180.221.4 ( talk) 10:25, 6 September 2012 (UTC)
It would be nice if the lede had a passage that stated the total number of deaths due to acute radiation poisoning, due to containing the disaster. I understand that deaths from cancer may be ongoing, but don't think that prohibits us from explaining in a simple way an important aspect of the immediate cost. - Stevertigo ( t | c) 05:43, 13 September 2012 (UTC)
You give numbers: “Total atmospheric release is estimated at 5200 PBq.” It means: 5200 PBq = 5.2 EBq = 5.2×1018 Bq = 140 MCi. In Russian version “Total atmospheric release is estimated at 14×1018 Bq.” It means: 14×1018 Bq = 14000 PBq = 14 Ebq = 380 MCi. In Russia these numbers are always in test and were checked many times. Your references [96, 97] about Fukushima. It seems like you give us understated numbers. Please correct. 05:37, 22 October 2012 (UTC) — Preceding unsigned comment added by 96.49.162.191 ( talk)
Removed All-caps comment related to Fukushima disaster at beginning of page. Comment removed for emotional opinion that has no place in an encyclopedic entry. Full figures comparing Chernobyl and Fukushima are dodgy at best given the full repercussions of the Fukushima disaster are still not fully known. 63.88.82.120 ( talk) 20:12, 12 October 2012 (UTC)Yardeditor
I didn't see it in the archives—though I'll easily admit I only went up through 2011, since the link in question was posted in October 2011—but I was wondering if this following link is relevant:
It's a video posted on the CIA's official YouTube page covering which apparently is the CIA's official video briefing of the disaster to Reagan, which apparently was declassified on or by November 2nd, 2011.
Now I personally think it may be relevant to the article, but, well, I'm not a regular Wikipedian, plus it says "No More Links", so I'll let someone else make the decision. If not a link, then a reference? — Nick15 ( talk) 02:32, 24 October 2012 (UTC)
In Chernobyl disaster#Health of plant workers and local people the following unreferenced statement appears:
This is a non-sequitur, as the WHO report was published in 2006, 20 years after the accident, which allows plenty of time for radiation-caused cancer fatalities. The word "thus" is clearly inappropriate, and gives me no confidence that the remainder of that sentence isn't simply an assumption based on some theory about latency periods. Perhaps it should just be removed, as it's remained unsourced for nearly a year and a half. Cheers, Fuzzypeg ★ 12:05, 30 October 2012 (UTC)
This claims to be "Contributions of the various isotopes to the (atmospheric) dose in the contaminated area soon after the accident". Is this really based on continuous measurements over 27 years, and were all these isotopes really present in these (relative) concentrations in the "contaminated area"? Including gases that readily disperse? And what is the "contaminated area": Chernobyl? Europe? To my understanding, data for the first several days at least was very limited, and included only simple radiation levels measured at a few locations, mostly close to the reactor itself.
Is this, then, simply a projection of expected isotopic decay based on assumptions about what isotopes made up the initial release? If so, it should be labelled as such, and not refer to any particular "area", or to being "atmospheric". And of course the phrase "soon after the accident" hardly applies to a graph with a logarithmic time scale stretching into decades. The file details in Wikimedia Commons are extremely vague about what the data really represents, how it was derived and what assumptions are made. If someone knows what this graph is about, please update the caption (and its file details). Otherwise, perhaps it should be removed from the article? Cheers, Fuzzypeg ★ 08:47, 30 October 2012 (UTC)
I believe this graph reflects the theoretical activity of all the fission products as they would appear in reactor fuel after shutdown assuming none were lost. Lesser reactor accidents (e.g., SL-1, Fukushima) primarily lost their more volatile and mobile elements (noble gases, iodine, etc) so this graph would not apply to those sites.
This graph is somewhat more applicable to Chernobyl because it was such an extreme case; a powerful explosion literally ejected much of the core into the environment. But you are still correct that the chart is theoretical, not an actual set of measurements.
I have read that Cs-137 now accounts for nearly all of the radioactivity now observed near the site, just as it does on Bikini Atoll where weapons were tested in the 1950s, but I would want to find an actual source before putting this in. Karn ( talk) 04:54, 27 February 2013 (UTC)
Hi all. I'm aware I've just been adding to this article, and probably I'll continue to add more. Yet the article is really too big. It's just over 150K, which according to WP:SIZERULE means it's way over size, and even I have difficulty navigating it. I suggest the following sub-articles be created:
It's possible that some other sub-articles could be created, or material in existing sub-articles could be rearranged, but let's not bite off more than we can chew, eh? We'll cross that bridge if/when we come to it. Any help/suggestions appreciated. Cheers, Fuzzypeg ★ 15:00, 30 October 2012 (UTC)
In this section, there are two paragraphs:
First of all, those two paragraphs contradict each other, since first paragraph says second explosion was runaway criticality, and second paragraph states other causes for the explosion.
Furthermore, reference 36 clearly states: "This result is matched up to a total reactor power of 3,200 MWt. However this estimate is not comparable with the actual explosion scale estimated as 10t TNT." Therefore, the reference itself says that the presumed runaway criticality did not cause the explosion.
Therefore, first paragraph should be removed, as it is not supported by it's own reference, and it is contradicted by the following paragraph.
-- 188.129.117.52 ( talk) 17:56, 29 December 2012 (UTC)
I don't see the contradiction between the paragraphs. The second paragraph gives the other hypotheses besides the nuclear excursion hypothesis that was ultimately accepted. That said, "runaway criticality" is not a very precise term, and "prompt criticality" is probably a better choice. That's a very rapid (time constant of milliseconds) exponential growth in reactor power when the chain reaction is maintained by prompt neutrons alone. Bombs and some special research reactors use prompt criticality; power plants normally do not.
Regarding the energy releases, I can't see the entire reference but I read the abstract and first two pages as saying that a large power spike did occur (the Xe-133/Xe-133m ratio was smaller than it would be for a power reactor, but not as small as it would be for a bomb) but that if the entire core had been involved the energy release would have been vastly larger than actually observed (i.e., 100-1000 kT, that of a good-sized nuclear weapon). So they concluded that the energy spike was generated in a small part (0.01%-0.1%) of the reactor core. Karn ( talk) 04:36, 27 February 2013 (UTC)
Several radiation rates and doses are given in secondary units that make no sense. For example, 5.6 roentgens (rads?)/sec is given as 1.4 milliamperes per kilogram. The actual dimensions of radiation dose are energy per unit mass, with 1 rad being 10 millijoules/kg. A dose rate would therefore have units of power per unit mass, so 5.6 rad/sec is equal to 56 milliwatts/kg. I'm making this change. Karn ( talk) 04:11, 27 February 2013 (UTC)
Never mind, the roentgen does have units of charge per unit mass. (Learn something every day...) The SI units of radiation exposure have units of energy per mass, with the gray being used for matter and the sievert used for biological tissue with a dimensionless "quality factor" depending on the type of radiation relating the two. If original sources giving doses and dose rates in rad or preferably grays can be found, they should replace the long-obsolete and never-standard roentgen. Karn ( talk) 04:19, 27 February 2013 (UTC) By: Seth Griner — Preceding unsigned comment added by 75.16.200.172 ( talk) 23:17, 6 March 2013 (UTC)
In the first paragraph/point, it contains the sentence: "Chernobyl's RBMK reactor, however, used solid graphite as a neutron moderator to slow down the neutrons, and the water in it, on the contrary, acts like a harmful neutron absorber." And the second paragraph say: "The upper part of the rod, the truly functional part that absorbs the neutrons and thereby halts the reaction, was made of boron carbide."
It's not very clear to me in the first paragraph why the absorptions is harmful in that particular case. Is it because graphite (and the water, too?) only partly absorbs neutrons as opposed to absorbing them significantly more when the boron carbide sections are inserted?
122.59.225.50 ( talk) 02:34, 11 March 2013 (UTC)
There seems to be a lot of controversy about whether graphite was the fuel for the fire in the reactor, or perhaps whether there was any real fire in the reactor going on at all, as opposed to simply a meltdown of red-to-yellow hot materials. There are several places in this article where a graphite fire is mentioned, but in only one place was it sourced, in a quote from Medvedev's book. It seems like the sort of "assumed" comment that one would make; after all, graphite is just compressed coal; one would think carbon burns, and pure carbon burns most easily. For Medvedev's part, he is a biologist, and that sort of burning might seem like an obvious assumption to a biologist.
This has proven not to be the case. It has been shown that the purer the carbon the better graphite resists fire, and that in fact it is extremely refractory in the purity required for reactors. There are plenty of citations for it to be easily able to resist burning at 1000-1800 degrees C, although it does seem to slowly erode and either sublimate or oxidize a small amount at a time, nothing near to being able to sustain an active fire. In many papers mention is made of heating it to 4-6000 degrees C without burning, far above any temperature that a reactor core, in meltdown or otherwise, could reach. Some have suggested that it might oxidize in the presence of very high heat and steam, like zirconium, reducing the water to hydrogen gas.
Are there any citations which support the possibility of a graphite fire in the reactor? The Sellafield/Windscale fire accounts seem to avoid graphite fires, more heavily leaning on uranium fire, which is certainly supportable. SkoreKeep ( talk) 22:09, 20 March 2013 (UTC)
Article says:
"As the reactor power output dropped further, to approximately 500 MW, Toptunov mistakenly inserted the control rods too far—the exact circumstances leading to this are unknown because both Akimov and Toptunov were killed during the later explosion."
Alexander Akimov article says:
"Akimov died two weeks after the accident due to Acute Radiation Syndrome, also known as radiation poisoning, at the age of 33."
Did he die in the explosion or did he die two weeks later? - Lapinmies 11:46, 2 April 2013 (UTC)
Hello! This is a note to let the editors of this article know that File:Chernobyl radiation map 1996.svg will be appearing as picture of the day on April 26, 2013. You can view and edit the POTD blurb at Template:POTD/2013-04-26. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Crisco 1492 ( talk) 22:50, 10 April 2013 (UTC)
I've added English subtitles for "Pripyat evacuation broadcast" soundfile by choosing CC-->Add subtitles-->en-English-->GO from the article's page. But subtitles added on the file's page ( http://en.wikipedia.org/wiki/File:Pripyat_1986.ogg). And soundfile's box at the article's page still says "No text tracks available". However, when I choose CC-->Add subtitles-->en-English-->GO from the article's page again it offers me to edit the subtitles I added before. Can anyone help? -- V001rus ( talk) 07:58, 18 April 2013 (UTC)
A recent edit (Remus Octavian Mocanu, 28 April) includes the following passage (my emphasis):
The bolded part looks very POV, and the whole section reads like an essay. Iapetus ( talk) 12:17, 30 April 2013 (UTC)
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Please move the following from the "Steam Explosion Risk" section to another section. While this information is interesting and pertains to the topic of the Chernobyl disaster as a whole, it does not contribute to explaining the steam explosion risk or how it was mitigated. It should also be noted that the sentences could be changed to read along the lines of "Hydrogen peroxide (H2O2) was generated during the accident by conversion of the Bubbler pool water, which was likely caused by intense the alpha radiation. This is proved by the presence of studtite and metastudtite in the Chernobyl lavas. These are the only minerals that contain peroxide.[65][66][67][68]" Note my intent here is only to combine what appears to be content from two separate people in a way that provides the same information but no longer looks as if it was written by multiple people at different times. The original section is contained below:
"It is likely that intense alpha radiation hydrolyzed the water, generating a low-pH hydrogen peroxide (H2O2) solution akin to an oxidizing acid.[65] Conversion of bubbler pool water to H2O2 is confirmed by the presence in the Chernobyl lavas of studtite and metastudtite,[66][67] the only minerals that contain peroxide.[68]"
RayEPreston ( talk) 23:15, 28 April 2013 (UTC) RayEPreston ( talk) 23:15, 28 April 2013 (UTC)
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Please change USSSR to USSR in "Deaths due to radiation exposure" under "Human impact." 71.158.169.111 ( talk) 06:18, 2 May 2013 (UTC)
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Under the Effects section of the article: the image description is incorrect. It is not a "Puppy with Dipygus..." it is a piglet. The Russian text in the image says so: http://upload.wikimedia.org/wikipedia/commons/0/02/Kiev-UkrainianNationalChernobylMuseum_15.jpg Msurkis ( talk) 08:53, 24 May 2013 (UTC)
Currently text states:
"A bigger problem was a flawed graphite-tip control rod design, which initially displaced neutron-absorbing coolant with moderating graphite before introducing replacement neutron-absorbing boron material to slow the reaction. As a result, the SCRAM actually increased the reaction rate in the upper half of the core as the tips displaced water. This behavior was known after a shutdown of another RBMK reactor induced an initial power spike, but as the SCRAM of that reactor was successful, the information was not widely disseminated.
A few seconds after the start of the SCRAM, the graphite rod tips entered the fuel pile." ...
This is partially incorrect. Russian wiki has a more correct explanation. I propose the following edition instead of the above fragment:
"A bigger problem was a flawed graphite-tip control rod design. In RBMK reactors, control rods occupy some of nearly 2000 vertical channels, most other channels contain fuel rods. Cooling water is pumped through each channel. A control rod has an absorbing section 7 meters long (same as channel height). When the rod is fully withdrawn, this section is situated above the core. If control rod would have nothing below this section, in this position its channel would be completely filled by water. Since in RBMK water isn't the primary moderating material (graphite is), presence of this water has slightly detrimental effect of absorbing some neutrons. To prevent this, RBMK control rods have another section, made from graphite, below the absorbing section. When the rod is fully withdrawn, this graphite-tip section is positioned in the channel where it displaces some water and improves neutron economy.
The flaw is that the graphite-tip section is not 7 meters long, but only about 5 meters long. When fully withdrawn control rod starts moving down, in the lower 2 meters of its channel the graphite tip displaces water, which increases power generation in this part of the core, instead of decreasing it.
When AZ-5 button was pressed, almost all control rods started moving down, thus the SCRAM actually increased the reaction rate in the lower part of the core as the tips displaced water. This behavior was known after a shutdown of another RBMK reactor induced an initial power spike, but as the SCRAM of that reactor was successful, the information was not widely disseminated.
A few seconds after the start of the SCRAM, the graphite rod tips displaced water in the lower part of the core."
Since the article is protected, I can't modify it. Can someone do this for me? Thanks. 85.71.196.161 ( talk) 01:03, 8 June 2013 (UTC)
Chernobyl abortions: leads one to assume that the abortions happened in chernobyl, or that chernobyl itself induced the abortions, it is therefore a misleading title, as it was the irrational phobia present in some parts of the general public, which actually precipitated people to seek abortions. Hysteria abortions, are what is being discussed in the journals, as radiophobia abortions falsely suggests that the phobia was so strong it spontaneously triggered stress responses that triggered involuntary abortions, which again, is not the case, people elected to get the procedure, out of fear.
Do you have another suggestion?
Boundarylayer ( talk) 11:31, 8 June 2013 (UTC)
Acording to this, and several other sources I found the last restrictions on livestock in the UK were lifited in 2012. http://www.telegraph.co.uk/news/uknews/9156393/Chernobyl-sheep-movement-restrictions-finally-lifted.html — Preceding unsigned comment added by 216.8.128.54 ( talk) 22:49, 13 July 2013 (UTC)
The radiation level cannot fall to zero, though it can approach it ever more closely. -- John ( talk) 05:36, 28 May 2013 (UTC)
I recently edited the article to show that there are two types of casuality estimates, those that are peer-reviewed and those that are not. However this was reverted by User:John
Here's the edit [2]
Thirty one deaths are directly attributed to the accident, all among the reactor staff and emergency workers. [1] An UNSCEAR report places the total confirmed deaths from radiation at 64 as of 2008. The Chernobyl Forum predicted eventual death toll could reach 4,000 among those exposed to the highest levels of radiation (200,000 emergency workers, 116,000 evacuees and 270,000 residents of the most contaminated areas); this figure is the total casual death toll, including some 50 emergency workers who died soon after the accident from acute radiation syndrome, nine children who have died of thyroid cancer and a future predicted total of 3940 deaths from radiation-induced cancer and leukemia. [2]
Based upon further extrapolations of the controversial Linear no-threshold hypothesis of radiation induced damage, down to zero, the Union of Concerned Scientists estimates that, among the hundreds of millions of people living in broader geographical areas, there will be 50,000 excess cancer cases resulting in 25,000 excess cancer deaths. [3] For this broader group, the 2006 TORCH report predicts 30,000 to 60,000 excess cancer deaths, [4]
In terms of non-peer reviewed publications, two affiliated with the controversial anti-nuclear advocacy group Greenpeace, have been released, one of which reports the figure at 200,000 or more. [5] The Russian founder of that regions chapter of Greenpeace, also authored a book titled Chernobyl:Consequences of the Catastrophe..., which concludes that among the billions of people worldwide who were exposed to radioactive contamination from the disaster, nearly a million premature cancer deaths occurred between 1986 and 2004. [6]
The book however has failed the peer review process, [7] [8] five reviews were published in the academic press, with four of them considering the book severely flawed and contradictory, and one praising it while noting some shortcomings. The review by M. I. Balonov published by the New York Academy of Sciences concludes that the value of the report is negative, because it has very little scientific merit while being highly misleading to the lay reader. It also characterized the estimate of nearly a million deaths as more in the realm of science fiction than science. [9]
Reported thus far are 237 cases of acute radiation sickness and 31 deaths.
balonov
was invoked but never defined (see the
help page).Boundarylayer ( talk) 23:31, 27 May 2013 (UTC)
Section 8.3 The Exclusion Zone has a number of errors. I made a few basic changes but don't feel comfortable tackling all of them.
An area extending 30 kilometres (19 mi) in all directions from the plant is known as the "zone of alienation". - I made corrections in the article in this sentence. It is largely uninhabited, except for a few residents who have refused to leave. - The number of samosels (resettlers) was 314 in 2009. I don't have more recent data so I'd say "about 300"
The area has largely reverted to forest, and has been overrun by wildlife because of a lack of competition with humans for space and resources. - overrun is an overstatement. Wildlife has increased overall, but many species populations are not healthy. See Mousseau et al: http://cricket.biol.sc.edu/chernobyl/Chernobyl_Research_Initiative/Introduction.html
Even today, radiation levels are so high that the workers responsible for rebuilding the sarcophagus are only allowed to work five hours a day for one month before taking 15 days of rest. - This is completely wrong. The radiation levels vary more than 1000-fold across the Exclusion Zone. Some areas have less radiation than outside the Zone. The text conflates the levels in the Zone and at the plant, where they are higher. Workers in the Zone historically mostly worked 15 days on, 15 off, but in the past 5 years there has been a shift to 4 on, 3 off. Lastly, no one is rebuilding the sarcophagus. There is a New Safe Confinement superstructure which is currently being built over the Sarcophagus.
Ukrainian officials estimate the area will not be safe for human life again for another 20,000 years.[56] - I have no information here In 2011 Ukraine opened up the sealed zone around the Chernobyl reactor to tourists who wish to learn more about the tragedy that occurred in 1986. - No, the zone has been open since at least 2005 maybe longer, it's just that in 2011 the Ukrainian National government recognized this as a money-making opportunity and started increasing publicity.
— Preceding unsigned comment added by Mfrphoto ( talk • contribs) 01:43, 6 September 2013 (UTC)
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The phrase "The Russian founder of that regions chapter of " in the overview section should have an apostrophe in "regions" so that it says "region's", because the plural "regions" is incorrect. The possessive "region's" is correct. Benbelly ( talk) 19:22, 4 December 2013 (UTC)
On 12 February 2013 a 600 m2 (6,500 sq ft) section of the roof of the turbine-building — Preceding unsigned comment added by 114.198.5.150 ( talk) 04:23, 5 December 2013 (UTC)
"Reactor 4 at Chernobyl consisted of about 1,600 individual fuel channels; each required a coolant flow of 28 metric tons (28,000 liters or 7,400 U.S. gallons) per hour" (section Accident) had an clarification needed tag with it, with the reason not possible, each 1600 fuel channel requires 28 tons of water an hour? please check source
I don't have acces to the source either (book), but although it seems like a huge amount, a quick calculation shows it's not unreasonable. 3200 MW power production means that amount has to be absorbed by the water, so these 1600 * 28000 litres of water would warm up by:
3,2 * 10^9 W * 3600 s / (4184 J/kg K * 1600 * 28000 L * 1 kg/L) = 61 K increase in warmth for the water.
This seems likely to me, so I have removed the tag.
EmilTyf (
talk)
16:38, 12 December 2013 (UTC)
Yes. It amounts to just less than 8 liters per second per fuel rod, which has a good feel. The water pumps in gigawatt-class water-cooled reactors are simply huge. A reactor document ( http://www4.ncsu.edu/~doster/NE405/Manuals/PWR_Manual.pdf) rates the Westinghouse pumps at 7000 HP, 100,000 gpm, (that's 3000 liters/sec) and there's 4 of them in an 1100 megawatt reactor. SkoreKeep ( talk) 08:54, 18 February 2014 (UTC)
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In the Evacuation Developments section, the sentence "A state commission was set up the same day (26 April) and tasked with investigating the accident." is preceded by a sentence referencing events on the 28th of April. The sentence should be changed to reflect that the commission was set up on the day of the accident; not the day of the announcement. "A state commission was set up on the same day as the accident and tasked with the investigation." 192.0.133.61 ( talk) 00:17, 3 March 2014 (UTC)
It's not clear from this sentence whether it was Ukraine or the nuclear plant "under the direct jurisdiction of the central authorities" of Soviet Union:
"[...] was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine (then officially the Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the Soviet Union."
Dchestnykh ( talk) 07:31, 26 April 2014 (UTC)
In terms of total radiation released, Fukushima is the worst nuclear disaster. Fukushima Daichi stored much more nuclear material onsite since it is a much larger complex than Chernobyl. Fukushima is the 10th largest nculear facility in the world, and Chernobyl did not even rank in the top 100. It is estimated that 80% of the entire fuel supply was lost to the environment according to independent studies. Furthermore, the highest radiation readings ever taken occurred in the area surrounding Fukushima. I am confused as to how Chernobyl could be considered the worst. Very dubious. — Preceding unsigned comment added by 76.240.172.212 ( talk) 00:22, 1 September 2014 (UTC)
18 billion rubles is 500 million US today, suggest adding to opening to put into perspective for wider western audience. — Preceding unsigned comment added by 203.47.198.254 ( talk) 05:26, 14 May 2014 (UTC)
Under overview, the statement "...several hundred million cancer cases are expected from other causes." - with no further quote from the citation is very misleading. If every person in the entire region through 2065 contracted cancer, that would still be a stretch?
The source is of course reputable and academic but it goes on to say immediately afterward which is not part of the current edit, "Although these estimates are subject to considerable uncertainty, they provide an indication of the order of magnitude of the possible impact of the Chernobyl accident." Trep26 ( talk) 03:44, 26 February 2014 (UTC)
→I don't mean to diminish how tragic this was and still is... just saying "several hundred million" sounds unreal/sensationalist and it doesn't seem possible. Trep26 ( talk) 04:04, 26 February 2014 (UTC)
The United Nations Scientific Committee on the Effects of Atomic Radiation, reports that more than 6,000 individuals, who were children or adolescents at the time they were exposed as a result of the accident, have contracted thyroid cancer since 1986. More cases are expected in the coming decades, and notwithstanding "the influence of enhanced screening regimes, many of those cancers were most likely caused by radiation exposures shortly after the accident". However: "There is no scientific evidence of increases in overall cancer incidence or mortality rates or in rates of non-malignant disorders that could be related to radiation exposure. The incidence of leukaemia in the general population, one of the main concerns owing to the shorter time expected between exposure and its occurrence compared with solid cancers, does not appear to be elevated. Although those most highly exposed individuals are at an increased risk of radiation-associated effects, the great majority of the population is not likely to experience serious health consequences as a result of radiation from the Chernobyl accident.". See: http://www.unscear.org/unscear/en/chernobyl.html — Preceding unsigned comment added by IanDM 005 ( talk • contribs) 23:43, 21 September 2014 (UTC)
According to two 2012 movies, natural wildlife was able to recover in the restriction zone. Cancer does not develop in fast reproducing short living animals. Misfit mutations were short lived, due to regular evolutionary forces, and normal populations appear to have outlived any abnormalities. No long standing effects have been found in fishing birds which eat fish with heavily contaminated radioactive bones.
I think all this is worthy of mention in a separate section. פשוט pashute ♫ ( talk) 09:09, 29 September 2014 (UTC)
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32 People Died Amediatly Benzy707 ( talk) 09:52, 25 November 2014 (UTC)
Not done Please see
Deaths due to the Chernobyl disaster -
Arjayay (
talk)
09:56, 25 November 2014 (UTC)
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Please remove: Germany has "banned wild game meat because of contamination linked to radioactive mushrooms".[128]
Reasons: Reference link [128] is dead and the sentence is easily misunderstood. Only wild boar meat showing radiation levels of more than 600 becquerel/kg is not permitted to be sold. The hunter is free to consume it himself, however. [1] The above sentence makes it sound like all wild game meat in Germany is contaminated and banned, which is not correct.
[1] http://www.forsten.sachsen.de/wald/2886.htm#article2906 (should be translatable by google) Breakareas ( talk) 20:28, 1 December 2014 (UTC)
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In the first section, 18 billion rubles is not worth 18 billion usd. And the syntax is wrong. My best guess is US$6071589000 according to http://rub.fx-exchange.com/usd/1986-exchange-rates.html 218.214.108.128 ( talk) 03:23, 22 December 2014 (UTC)
In the section "Effects", there is a picture of a disformed animal, and it is said to be a piglet. However, in the Norwegian (bokmål, not nynorsk) article, it is said to be a hundevalp, which apparently means (dog)puppy (I do not speak Norwegian, but it is very similar to Swedish, and dogpuppet is hundvalp in Swedish). So my question is: which of these is true? K9re11 ( talk) 13:25, 20 April 2015 (UTC)
I rarely comment on even the most politically biased articles I see - since it has proven to be more than pointless,
however since today is 26.04 and these events did happen precisely 29 years ago - I would like to make one comment, if Wikipedia community will react to it in any way or not is up to you.
I find it ridiculous that 29 years later, the official politically biased story is still published even in "politically unbiased" places like this one (Wikipedia article).
For example the statement that: "The reactor was in an unstable configuration that was clearly outside the safe operating envelope established by the designers." is the same false statement which was used to place all of the blame on the operators and engineers of the plant - the same people who Knowingly gave their lives to try to contain the disaster.
It was a statement created in order to clear all of the responsibility from the constructors and the local regulators at the time... however - the truth is, that as strange and mind boggling the actions of the people in the control room may look today, they were operating the reactor exactly WITHIN the safety limits and margins according to the instructions at the time. The fact that these instructions were not adequate is completely different story. But they were written by the constructors of the reactor - there is plenty of references out there (including in the list of references of the main article) which include the very same safety instructions used at the time. It is easy for us today to say that these people broke the rules - today we know a lot more about these reactors, however the truth is that even if their actions seem to be not 100% understandable today, they did not break any rules. The rules at the time were inadequate. Only AFTER the accident the rules and safety margin estimations were updated, even the design of the RBMK reactors was updated in order to make them inherently safe - but that happened AFTER not before the accident.
The article also quotes Valery Legasov stating "It was like airplane pilots experimenting with the engines in flight." The very same Legasov, who comitted a suicide 2 years later, and who did leave a tape proving that the official reports have been modified in order to clear the responsibility from the constructors of the reactor.
Naturally the discussion about who did what and why in this accident can last till the end of time - and this really is not the point of my comment (which became obnoxiously long). The point really is that this statements do not belong in a unbiased encyclopedic article. Or if they MUST be there, they should be presented on even ground with all other analysis published in the later years. Stating that this was the truth and the only truth about this accident is simply wrong and in my opinion well under the level of Wikipedia.
Perhaps a serious and more unbiased rewriting of this article, combined with proper cleanup might help the people who use this article as a learning tool. Sailor MikeFIN ( talk) 19:35, 26 April 2015 (UTC)
There are issues with the identification and links to an OECD technical report on the accident: Chernobyl, Ten Years On, Assessment of Radiological and Health Impact. Original dated 1995. Then updated in 2002. Both reports can be accessed from OECD website, the 2002 version content is posted at least in part on the OECD website. The 1995 report here: https://www.oecd-nea.org/rp/chernobyl/chernobyl-1995.pdf. The 2002 update here: https://www.oecd-nea.org/rp/reports/2003/nea3508-chernobyl.pdf.
It appears that the 2002 update is being referenced in most cases, and it should be referenced as it is more current. Ref 109 should reference Ch.2 of the 2002 report. References 31, 44 and 85 should be merged and reference Ch.1 of the 2002 report.
Reference 111 appears to reference the original 1995 report, although it states it was released in 1998, and the actual link provided is a hard-to-follow link to a journal article that likely summarizes the 2002 update. The link should go directly to the 1995 report.
The text in second paragraph under Section on Radioactive Release refers to "two 1998 reports", with two links provided. One link is to the above 1995 OCED report. The other reference 109 links to a citation database, and the citation is actually for a 1989 Health Physics article. The article is an appropriate reference, but is inconsistent with the text that implies this is an OSTI 1998 report. If there is a 1998 OSTI report, then this link needs to be changed. Otherwise the 1989 Health Physics article is fine, but the text in the article needs to be changed.
I propose to combine and update these links, but am posting this first to explain the proposed change and in case there is some history on these links to discuss. Gierszep ( talk) 21:08, 30 May 2015 (UTC)
I don't know if "What if" scenarios are really within the scope of the article but serious estimations by credible sources of what would have been the effects of the steam explosion, had the three men not managed to open the valves, would be appreciated. Especially since one is constantly confronted with utterly sensationalist claims such as vast parts of Europe being turned into Fallout wasteland etc.
Currently the article only states that more radioactive material would have been ejected from the reactor. — Preceding unsigned comment added by 2A02:8108:1E00:1924:C108:152F:61E3:2ADA ( talk) 00:56, 6 August 2015 (UTC)
I refuse to believe that the casualty # is 31 direct. If the information is unknown than make that known.
There is another collision in same section; section: "Steam turbine tests" Statement: "The Chernobyl power plant had been in operation for _two years_ without the capability to ride through the first 60–75 seconds of a total loss of electric power" (note: _two years_) and few lines above we can read: "An initial test carried out in _1982_ showed that the excitation voltage of the turbine-generator was insufficient; it did not maintain the desired magnetic field after the turbine trip. The system was modified, and the test was repeated in 1984 but again proved unsuccessful. In 1985, the tests were attempted a third time but also yielded negative results. The test procedure was to be repeated again in 1986"
So how Chernobyl power plant had been in operation for _two years_ without the capability to ride through the first 60–75 seconds of power loss when _first_ tests was conducted FOUR years prior disaster ("An initial test carried out in _1982_") for same reasons? Calimero ( talk) 00:12, 25 November 2015 (UTC)
Answer: 26 April 1986 test is not reactor working condition test but exercise (drill) test to see what happened when plant is losing power. For reactor, "Two years" is correct, the reactor is connected to grid in 1984.
"These were the engineers Alexei Ananenko (who knew where the valves were) and Valeri Bezpalov, accompanied by a third man, Boris Baranov [...] All of them returned to the surface and according to Ananenko, their colleagues jumped for joy when they heard they had managed to open the valves. Upon emerging from the water, the three were already suffering from radiation sickness and later died."
It looks like Bespalov was still alive in 2008, There's even a photo of him here with the following tag: "Валерий Беспалов, сотрудник с 25-летним стажем, начальник смены первой очереди ЧАЭС. Лично контролирует состояние отработанного топлива в отключенном реакторе первого эторгоблока. Называет себя патриотом станции" Gyurika ( talk) 19:59, 3 May 2015 (UTC)
Beata Li Caused this event — Preceding unsigned comment added by 216.165.126.103 ( talk) 16:58, 15 May 2015 (UTC)
"there may have been several Bespalovs at Chernobyl" And what do you base this hypothesis on? Do you have any sources, that prove that there were multiple Valeriy Bezpalovs both working there in the 1980s? Gyurika ( talk) 08:22, 7 August 2015 (UTC)