Talk:Chernobyl disaster/Archive 8

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Fallout Comparison

"400 times the fallout". This claim has been tagged as dubious for a while without anyone supporting it. This claim has several problems. First, it is demagogic and overly dramatic in tone. Secondly, the work of SCOPE (see [1]) suggests such comparisons are impossible; they are inherently "apples to oranges" comparisons. Third, it leaves a false impression in the reader's mind. Hiroshima may have killed as many as 100,000 people from fallout. Yet a release some four hundred times larger has killed possibly as few as 20, and certainly no more than 4,000? Even the source in this case points out that "Early estimates that tens or hundreds of thousands of people would die from Chernobyl have been discredited."

Properly caveated, it might possibly have some relevance elsewhere in the article, but it has no place in the lede. Fell Gleaming^(talk) 00:11, 20 April 2010 (UTC)

That is basically an argument from personal incredulity, a classic logical flaw. The fact is well-sourced; it comes ultimately from Ten years after Chernobyl: what do we really know?, published in 1997 by the International Atomic Energy Agency (which I'm sure you would accept as an authority). The source states (page 8): "The Chernobyl explosion put 400 times more radioactive material into the Earth's atmosphere than the atomic bomb dropped on Hiroshima." Your "false impression" is, I'm afraid, one that is based on ignorance; Hiroshima killed so many people because it was a nuclear explosion with associated blast, fire and radiation effects. Contamination was relatively minor. That's why the city was rebuilt so quickly. Chernobyl's death toll was almost entirely due to radioactive contamination rather than the initial blast and fire. -- ChrisO (talk) 08:09, 20 April 2010 (UTC)

If the fact comes from the IAEA, it should be sourced to them. In any case, the language as stated is unnecessary dramatic and misleading. I've preserved the material, but placed it in the section describing the aftermath, rather than the lede. Fell Gleaming^(talk) 14:44, 20 April 2010 (UTC)

The mass of radioactive fallout is both quantifiable and provable. The actual meaning of that much fallout can indeed be apples-to-oranges, but not in the way you suggest.

First, "100,000"? That's the total number of people that died at Hiroshima from all causes, including fire, blunt-force trauma, etc. It's not just the ones who died from radiation sickness, much less sickness caused by residual fallout.

Second, the deaths from radiation sickness at Hiroshima were almost all caused by the dose they absorbed when the bomb went off. As nuclear explosions go, Hiroshima was fairly "clean" for fallout. Abhorrent, yes, but "clean" for fallout.

Third, the deaths caused by X amount of fallout in a concentrated population center will perforce be many times greater than the deaths caused by X amount of fallout in an area that's mostly wilderness. That is the true apples-and-oranges fallacy contained in your argument.

If that statement is being used to evoke the argument "...and therefore Chernobyl killed 400x as many humans", then you would be right in claiming that it's being used falsely. But to claim it should be erased or hidden elsewhere despite its meaning in terms of environmental damage is to whitewash provable scientific fact in the interest of making Chernobyl seem like no big deal. 76.22.25.102 (talk) 16:10, 13 May 2010 (UTC)

Then please someone should add that most of the radiation >99.99% at Hiroshima was caused went the bomb went off, not the contamination. I'm currently working on it.64.18.166.155 (talk) 15:27, 16 May 2010 (UTC)

Neutrality disputed

This article is not by any stretch neutral. It reports a widely criticized, highly contentious report from the IAEA, which is not a scientific organization, as accurate and hardly mentions others criticizing that report. If this article doesn't include reasonable caveats about the IAEA report being heavily disputed, it will be seen as partisan hackery by anybody with ANY level of knowledge of the matter. End of message. —Preceding unsigned comment added by 130.184.253.7 (talk • contribs) 02:31, 3 April 2010 (UTC)

Do you have any references for this criticism? (Blogs and other self-published web sites do not meet Wikipedia WP:RS standards) Please give us a few links, if you have them. --Nigelj (talk) 17:58, 28 April 2010 (UTC)

The IAEA's main goal is to promote the use of nuclear energy for power generation. That should definitely be considered. There is a claim in the article that a piece of IAEA data confirms an UNSCEAR piece of data, namely: "In addition, the IAEA states that there has been no increase in the rate of birth defects or abnormalities, or solid cancers (such as lung cancer) corroborating UNSCEAR's assessments.[127]"

I don't think this serves to corroborate anything UNSCEAR has said, it is an entirely new piece of information sneaked in under the guise of supporting data. It leads me to question the article's neutrality, at least in this section. While UNSCEAR should be a good source, there should definitely be some caution around what the IAEA say given their interests; at the very least their claims (which are widely contested) should be accompanied by opposing opinions. 192.198.151.36 (talk) 10:00, 4 May 2010 (UTC)

http://whqlibdoc.who.int/publications/2006/9241594179_eng.pdf Here's a link to the WHO report that clearly states the limitations of assessing sold cancer risks (other than thyroid) within a couple of decades of the accident. the conclusion in chapter 5 is a good place to look if you don't want to read the whole thing. 192.198.151.37 (talk) 10:25, 4 May 2010 (UTC)

Apologies for bombing this with comments but I've one more thing to say. I believe the health effects section should not be lead by the mental health subsection. The layout in the WHO report has a much more logical flow. I think being an article about a nuclear disaster it should begin with radiation related effects, perhaps chronologically would work. Actually the reason I came to this talk page to post all this was because I was happily reading the article and when I came to the mental health part I found it poorly written, unsourced, distasteful and potentially offensive. Good day. 192.198.151.37 (talk) 10:37, 4 May 2010 (UTC)

Article prose...

...is not what it once was. I'm not sure exactly what has changed since the last time I had a look, but it's no longer as easily read or as readily understood as it used to be. Is this related to the work discussed above?

J.M. Archer (talk) 19:58, 18 February 2010 (UTC)

Another note, actually:

Some of the modifications made to the text follow logically as responses to the text that was present before the changes were made but make less sense standing here alone. Readers can't be expected to have seen both versions of the text and that's just not the way an encyclopedia is supposed to work: whatever the technical reality is, there is only one Wikipedia article on the Chernobyl disaster. It needs to be complete as presented. I've copypasta'd an example below.

All of them returned to the surface and according to Ananenko, their colleagues jumped from happiness when they heard they managed to open the valves. Despite their good condition after the task completion, all of them suffered from radiation sickness, and at least two of them - Ananenko and Bezpalov - died in the process.

This seems almost a non sequitur as presented in the article. It feels out of place in context: there is no reason for the reader to assume they did not make it out, as the article says nothing of the kind. I personally happen to know--and a reader might discover from the article's history page--that this section once claimed that the three divers did not return to the surface and that all died immediately. This snippet seems to make sense as a rebuttal of the older version of the article, but that serves no purpose: there is no reason to rebut a version that is not present, and that the reader has not read.

I can't imagine this being a common practice and would like to see some of these bits and pieces made to fit better within the context of the article but don't necessarily know enough about the event itself to ensure that I can make changes without screwing up details.

J.M. Archer (talk) 20:44, 18 February 2010 (UTC)

Pretty much. "So some things happened, but on the other hand those things didn't really happen, and then other things happened that happened because more things happened, except that things didn't happen because things happened, and who knows what things happened that caused things to happen. In conclusion, 50 people died immediately and 4000 people died later from cancer, but no one really knows how this happened."

But I'm afraid you're completely wrong in thinking this isn't common practice. It's one of the worst, but it's only one example of the round-robin effect of Wiki editing, AKA "Too many cooks spoil the broth". Throw a dozen people in a room with typewriters and axes to grind, and you don't wind up with Shakespeare - you wind up with an uneasy ceasefire after one side outblusters the other, everyone gets something they want thrown in, and all coherency has been lost.

The most flagrant example (of many) demonstrating that 1) people are too scared of starting more flamewars to make meaningful edits and 2) the semi-victorious side was "It was all the fault of the dumb staff and this was blown out of proportion", paraphrased:

Mental health effects: The media scared a lot of people into thinking they were sick. Some people even died from it because they were so scared. The fact that their symptoms from being scared were the same as radiation sickness just goes to show the power of suggestion.

(Amazingly, this has survived over 500 edits despite being patently ridiculous and having no sources to support it.)

Before someone chirps in with the rote "Be bold, be bold, be bold!" claptrap - there are a lot of reasons I gave up on Wikipolitics and became an occasional IP. Chief among them is the fact that "Being bold!" only gets you slow suffocation from well-meaning discussio ad infinitum at best, ulcers and angry stalkers at worst. If you actually think that nothing should be done, isn't "Be bold!" encouraging a person to waste time doing work that someone else will need to waste time deleting? And if you actually agree that something should be done, aren't you saying "Well, yeah, there is a problem - and you should be punished for calling attention to it instead of pretending it's not there like everyone else"? 76.22.25.102 (talk) 15:48, 13 May 2010 (UTC)

For reference, "Mental health effects" in the above comment refers to a subsection deleted in this edit. Somehow, though, I don't doubt that someone will come forward to claim that it was deleted hastily (despite it being up for over half a year with the tag showing it needed sources) and/or that it should be kept while it's discussed for another year or two. 76.22.25.102 (talk) 17:34, 13 May 2010 (UTC)

I echo the sentiments above - without knowing exactly how or what I would do to change it, I do know that this article was once much better written. Slac speak up! 12:22, 19 July 2010 (UTC)

Cooling after a Scram Required?

Challenging second paragraph within the first subsection "Accident". More specifically, "Nuclear power reactors require cooling flow to remove decay heat ... . If not immediately removed by coolant systems, the heat could lead to core damage." This is a lead into the third paragraph that talks about the requirement for forced cooling by use of reactor coolant pumps (RCPs) (although, this is a RBMK, so unsure of the true title of those pumps). It is not true that "nuclear power reactors" need forced cooling after any type of shutdown. They are designed to lose all power, trip the reactor and survive using Auxiliary Feed Water Pumps (AFWP) to maintain water level in the Steam Generators. This maintains a heat sink within the primary loop and will in turn induce natural circulation within the primary loop. That's for PWRs, which is rather different from a RBMK as it's essentially a BWR. I am not an expert with BWRs, so I won't go into them for now. Something for me too look up. But as for PWRs, RCPs aren't even a safety load and are not required for a normal nor emergency shutdown. Hence, "nuclear power reactors" are designed to survive without forced cooling. So this second paragraph is somewhat correct, but vague and misleading, when it generally states that the core needs "cooling flow". Vague because it doesn't say what type of "cooling flow", yes there are two general type in nuclear engineering: natural circulation and forced. Misleading because it continues to talk about how the RCPs for the RBMK are safety loads and are needed after a shutdown.

I propose that we make a small edit to the second paragraph. We need to be more specific to the types of reactors that have this cooling requirement and also to be more descriptive to the type of cooling needed. Gilawson (talk) 17:14, 27 May 2010 (UTC)

Made minor change to 2nd paragraph in bold reaction to your comment. It is safe to conclude that, even though it is a graphite moderated BWR, the RBMK does rely on "coolant flow" to provide decay heat removal. Cheers - Williamborg (Bill) 21:14, 27 May 2010 (UTC)

Not sure what is meant by bold. I will try to read that article more thoroughly to understand it. My point was what kind of "coolant flow". You just restated the vague and misleading statement that a (or in this case any) nuclear power reactor needs "coolant flow". Does the RBMK require forced cooling after a normal shutdown or an emergency shutdown? But what I can tell you is that a PWR Generation II doesn't require forced cooling after any type of shutdown to avoid damage. It seems that a RBMK does and therefore that sentence needs to be changed as it talks about nuclear power reactors in general and talks about this vague concept of "coolant flow". I will edit this paragraph myself after waiting for sometime for more responses and help in this matter. Gilawson (talk) 08:09, 28 May 2010 (UTC)

<== Appreciate your desire for accuracy and precision. My thoughts, combined with recollections from 20 years ago:

• Although I understand the desire for precision, this is an introductory paragraph and emphasis on technical precision may make it more difficult for the average reader to understand key points. That said, Einstein's guidance - to make everything as simple as possible, but no simpler - probably applies here. So let's see what we can do to respond to your request for more precision.
• Most power reactors require continued coolant flow upon scramming after protracted operation for decay heat removal to limit the risk of core damage; the HTGR has sufficient thermal inertia to sustain the thermal transient without flow. The important point here is that the RBMK-1000 requires continued cooling following a scram/trip from power after an extended power run.
• The RBMK is a graphite-moderated pressure-tube boiling water reactor with vertical pressure tubes. So as a boiling water reactor, the coolant flow is actually feed-water flow.
• The RBMK-1000 reactor (all 4 units at Chornobyl/Chernobyl were RBMK-1000s) have two independent primary coolant loops, each cooling half the reactor.
• Each loop has 4 cooling pumps operating in parallel - nominal full power flow of ~2000 liters/second is produced by 3 pumps per loop. The 4th pump provides redundancy.
• Coolant enters the pressure tubes (pipes - the Russians typically translate their term for pressure tube as channel) and flows upward through the core, where it is heated by fuel elements in the pressure tubes.
• Power is removed by coolant heating and phase transition (boiling) as it ascends in the pressure tube - creating a steam-water mix. After passing through a pair of parallel drum-type steam separators, the steam is piped to the turbines.
• From the turbines the condensate is routed back to the feedwater.
• Fission products accumulate during operation at power. The equilibrium level of fission product accumulation depends on power level - primarily on that power level shortly before shutdown. If the reactor has operated at 100% of rated power for an extended period, the decay of fission products produce 7% power immediately after scram - this power decreases with time.
• Following a scram, decay heat is removed by boiling; makeup water (coolant flow) is required during the initial cool-down period.
• The purpose of the test which initiated the accident was to demonstrate that the turbine coast-down could power decay heat removal (i.e., continued coolant makeup) upon a loss of offsite power.

I wish you well in finding a wording you judge is better. Be WP:Bold and make the change to that text when you think that you've got it right.

Cheers - Williamborg (Bill) 03:45, 29 May 2010 (UTC)

I was surprised by your assertion that "But what I can tell you is that a PWR Generation II doesn't require forced cooling after any type of shutdown to avoid damage" but thought I may be out of date. Since this was contrary to my understanding, I did some research. Specifically I reviewed the "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition (NUREG-0800)". United States Nuclear Regulatory Commission. May 2010. Retrieved 2 June 2010.. Section 5.4.7 titled "RESIDUAL HEAT REMOVAL (RHR) SYSTEM" (Revision 5 which is dated May 2010) deals with decay heat removal in the residual heat removal (RHR) discussion. It specifically discusses using the reactor coolant system (RCS) during and following shutdown and applies to all currently licensed PWRs and BWRs as well as to any new PWR Generation II license submittals. The reference makes it clear that decay heat removal using active coolant flow is required. Just to make sure I did not misunderstand, I spoke with a gentleman involved in the U.S. NRC licensing review of a recent PWR Generation III reactor license submittal (the Advanced PWR (APWR) - nominally Gen-IV PWR from Mitsubishi Heavy Industries) - he assured me that NO Generation II or III reactor design currently exists that does NOT require active cooling for decay heat removal following a scram after extended full power operation. The original wording which you challenged - "Nuclear power reactors require cooling flow to remove decay heat ... . If not immediately removed by coolant systems, the heat could lead to core damage." - remains correct. Hence I doubt that a reference exists for the assertion that "But what I can tell you is that a PWR Generation II doesn't require forced cooling after any type of shutdown to avoid damage." Therefore I will revert the text to the original form.

Skål - Williamborg (Bill) 18:18, 2 June 2010 (UTC)

Took some time, but I got a Final Safety Analysis Report (FSAR) of a Generation II PWR Westinghouse Three-Loop Power Plant. I'm very busy this week, so will make this short, then I will fully address this issue next week. But in the FSAR, it says that you do not need Residual Heat Removal System (RHRS) to maintain Hot Standby, which is Mode 3. Mode 3 is 0% Power, Subcritical conditions (I think it's <0.99, I'll double check that later), and Reactor Coolant System (RCS) temperature of 250 - 350 F (I'll have to double check the temperature). It states that you need AFW in order to maintain the Steam Generators (SGs) as a heat sink and this will create a natural circulation condition sufficient enough to remove decay heat. A SCRAM due to Loss of Offsite Power (LOSP) happens a lot in the industry, the best example is when the North East of USA and areas of Canada had a major blackout. Almost 20 nuclear power plants experienced a LOSP and they all lost their Reactor Coolant Pumps (RCPs) (this applies to PWR). Nuclear power plants don't consider RCPs safety loads, so they are lost and never recovered without Offsite power. Hence, without RCPs, you lose Forced Cooling in your RCS, HOWEVER, there was not one report of core damage from those power plants or any other power plant that is designed to handle a LOSP. Generation II are designed to survive a LOSP event resulting in Natural Circulation of the RCS. Some plants will then choose to return to Mode 1 from Mode 3, or some will decided to move to Mode 5 or further by use of their RHRS. It takes a considerable amount of time to hook your RHRS up to your RCS due to safely depressurizing and lowering your temperature of the RCS. RHRS in general can only operate with the RCS when the RCS is in the 300's in regards to both temperature (F) and pressure (lbs). So I finish this "short" response saying that Generation II PWRs do not require forced cooling to maintain a shutdown condition, or more specifically Mode 3. I will make reference to the FSAR shortly. Your problem is that you loosely refer to a shutdown or use the word "immediately" after a shutdown is just not true. It's very simple and happens all the time: RCPs tripping will cause a Reactor Trip, your RCPs begin to coast down and you start to loose forced cooling as the Reactor is tripping (< 2 seconds). Very soon after you are left with no RCPs running and your rods resting at the bottom of the core and these reactors survive every time, they are designed to according to the FSAR. Gilawson (talk) 21:40, 14 June 2010 (UTC)

I reviewed your source. You are referring to a SRP! That's a guideline for NRC staff! I quote from the documents which is located on the front page of every section, "This Standard Review Plan, NUREG-0800, has been prepared to establish criteria that the U.S. Nuclear Regulatory Commission staff responsible for the review of applications to construct and operate nuclear power plants intends to use in evaluating whether an applicant/licensee meets the NRC's regulations. The Standard Review Plan is not a substitute for the NRC's regulations, and compliance with it is not required." This is a very bad reference to use to justify what a nuclear power plant can and cannot do. But either way, I tried to read into it to find what you were trying to show and couldn't find it. Actually, I found the opposite in section 15.2.1. - 15.2.2. "In all light-water-cooled reactors, sensible and decay heat can be removed through actuation of one or several of the following systems: steam relief system, steam bypass to the condenser, reactor core isolation cooling system (BWR), emergency core cooling systems, and auxiliary feedwater system (PWR)." I hope this shows you that this is a bad reference as it's just a guideline of what NRC staff should adhere to when licensing a nuclear power plant.

I'll copy section 7-4 Systems Required for Safe Shutdown from a FSAR of a PWR in the USA:

7.4 Systems Required for Safe Shutdown* The functions necessary for safe shutdown are available from instrumentation channels that are associated with the major systems in both the primary and secondary of the Nuclear Steam Supply System. These channels are normally aligned to serve a variety of operational functions, including startup and shutdown as well as protective functions. There are no specifically identifiable safe shutdown systems: however, prescribed procedures for securing and maintaining the plant in a safe condition can be instituted by appropriate alignment of selected systems in the Nuclear Steam Supply System. The discussion of these systems together with the applicable codes, criteria and guidelines is found in other sections of this safety analysis report. In addition, the alignment of shutdown functions associated with the engineered safety features which are invoked under postulated limiting fault situations is discussed in Chapter 6 and Section 7.3. For a description of systems required for safe shutdown due to fire, refer to Safe Shutdown Analysis in case of fire (SSA). The instrumentation and control functions which are required to be aligned for achieving and maintaining safe shutdown of the reactor that are discussed in this section are the minimum number under non-accident conditions. These functions will permit the necessary operations that will: a) Prevent the reactor from achieving criticality in violation of the Technical Specifications, and b) Provide an adequate heat sink such that design and safety limits are not exceeded. The modes of shutdown are defined in Chapter 16 as follows:

Mode No.	Mode Condition	Reactivity Keff	% Thermal Power**	Rated Avg. Coolant Temperature
3	Hot Standby	<0.99	0	≥ 350 F
4	Hot Shutdown	<0.99	0	350 F > T avg. > 200 F
5	Cold Shutdown	<0.99	0	≤ 200 F

• Further information is contained in the TMI Appendix.
• Excluding decay heat

7.4.0-1 Amendment No. 50

• • • NPP FSAR

7.4.1 Description Functions required to achieve and maintain the above conditions of shutdown are: a) Proper boration and reactor coolant inventory b) Auxiliary feedwater supply c) Removal of residual heat 7.4.1.1 Systems & Equipment Used for Modes of Shutdown. Systems and equipment used for the modes of shutdown include: (Note: The equipment listed below which is preceded by an asterisk (*) is considered required for the mode of shutdown described. Equipment not preceded by the asterisk is desirable, but not required).
a) Hot Standby

• Auxiliary feedwater system
  
• Boric acid transfer pumps
  
• Steam generator safety valves (No I&C required)
  

Reactor Coolant Inventory Control (CVCS)
Letdown

• Charging
  
• Pressurizer heaters
  

Pressurizer sprays

• Steam generator power operated relief valves
  

Pressurizer power operated relief valves
Reactor Coolant Pump (with auxiliaries)
b) Hot Shutdown

• Auxiliary feedwater system
  
• Boric acid transfer pumps
  
• Steam generator PORV's
  

Reactor coolant inventory control (CVCS)
Letdown

• Charging
  
• Residual heat removal pumps (p < 363 psig)
  

Pressurizer heaters and sprays (if not solid)
Pressurizer power operated relief valves
Reactor Coolant Pump (with auxiliaries)

• Accumulator isolation valves
  

c) Cold Shutdown

• Residual heat removal system
  

Boric acid transfer pumps
Reactor coolant inventory control (CVCS)
Letdown
Charging
7.4.1-1 Amendment No. 48

• • • NPP FSAR
      

Supporting systems and associated equipment required for the modes of shutdown include:

• Component Cooling Water System
  

~* Service Water System
~* Onsite Power Supply System - diesel generators and batteries

• Diesel Generator Fuel Oil Storage and Transfer System
  

26 HVAC Systems/Chilled Water for areas containing equipment required for the modes of shutdown
~* ~ Control Room Panels or Auxiliary Control Panel
* ~ Emergency Lighting

Sorry, the paste and copy was a bit messy, I tried to clean it up as much as I could. I would be interested if you could find a good reference that says that a PWR needs forced cooling immediately after any type of shutdown. Also that a PWR requires forced cooling to maintain a shutdown mode, more specifically Mode 3. But as you can see for yourself, in order to achieve Mode 4 or 5, you do need forced cooling by the use of your RHRS. But again, Mode 3 is a shutdown mode too. Gilawson (talk) 01:38, 15 June 2010 (UTC)

Pumps, Backups, Chernobyl and the Bible, politics, picking holes in the article, noticing failures in the design and alleviating public fear of nuclear power

Let me point out some little comments of my own in bold type Sorry for my english. (I do not have experience in nuclear plants, but I´ve been working in convencional ones for several years)--Xareu bs (talk) 16:03, 1 September 2010 (UTC) This article will be receiving a lot of views with regards to nuclear plant failures and, so, has the potential to spread a lot of undue negative vibes. I suggest we aim to write it such that it doesn't spread unnecessary negativity about this method of generation. I haven't directly edited the article as I'll undoubtedly be reprimanded by angry critics if I do so. Instead, I'll present my questions in the discussions page.

First of all, 5.5 MEGA watts to run the coolant pumps? Damn! Those must have been some mighty powerful pumps. As I understand it, the backups were being used to power all the emergency systems. That amount of power for even a 28 ton per hour pump is gigantic. If they weren't pumping at high pressures, the 5.5 MW generators will have been used for other systems. You don't need 5.5 MW to move 28 tons per hour at low pressure. If they just had it all in a tower above the reactor, that'd do. Even the normal 30m high towers will produce almost 50psi of pressure and the rooftop tanks will hold two hours worth of coolant at those drainage rates. The purpose built towers will hold more like tens of thousands tons of water. A water tower could have bridged the minutes gap with orders of magnitude left to spare. They could have done away with the backup pumps. I think you are mixing up circulating pumps (condenser cooling), with reactor cooling pumps (primary side on a PWR scheme). 3000 MW of thermal energy is a fair amount of energy to be disipated.

Like my own reply, I believe the description of the backups is long winded, going into details about how a generator works. It would be sufficient to say, the "turbines couldn't provide a stable supply to the pumps".

Why is the chief designers name capitalize?

Why does the section on the tests claim two different test output for the same test?

Why does it then list one test output in mega watts and the second in milli watts. I'd be impressed to see a pile of that size outputting milliwatts. STOP posting in scientific articles if you can't get the unit prefixes right. Yes, it's obvious. No, it's most definitely NOT okay.

Were battery backups and switchmode supplies beyond the designers of a nuclear power plant? The pumps won't have needed 5.5MW alone. They wouldn't even need the switchmode supplies, they could have just chained batteries together. Or built a water tower. I get the feeling they were using a blanket term for emergency power, meaning maintaining all the lights as well as the pumps. They should have had differing levels, blacking the plant out if need be to keep the pumps running. I do not get the point of chained batteries. I do not think you are talking about a DC back up system for such a big power, are you?. As for the water tower/tanks, were they considered in Soviet designs?. Can they cope with the water flow needed to refrigerate a 3000 MW heat exchanger until the diesel units get synchonised and loaded?. "but also to perform a detailed investigation of the bearing."

"The radiation at Level 0 was too high and they ,Popov and Savenkov, received a high (not needed, high has already been used in the sentence) dose that proved to be lethal." Grammar people, grammar.

"As planned, on 25 April a gradual reduction in the output of the power unit was begun at 01:06 a.m., and by the beginning of the day shift the power level had reached 50%." There were four reactors in the chain and the total output on todays modern reactors is around 1GW. Each of the four in the chain would be outputting 1GW. So a 50% reduction would be 500MW, not 700MW and most definitely not 800 milliwatts.

"Further rapid reduction in the power level from 50% was actually executed during the shift change-over." No explanation, no references. Why would they have been doing that?. That´s the issue, a misoperation in a bad moment.

"The test plan called for the power output of reactor 4 to be reduced from its nominal 3200 MW thermal to 700–1000 MW thermal." I may be mixing up thermal with electrical output, but most modern reactors are geared towards 1GW. There were four in this chain, suggesting each was outputting 1GW to reach the chains 4GW total. The turbines are often extremely efficient, so claiming they were thermally outputting four times their electrical output, each, is dubious. What´s the beef with that?. In PWR heat exchangers, only around 1/3 of the thermal megawatts turn into electrical energy in the turbogenerator, and it´s not only due to the losses in the turbine. It´s what a Rankine cycle takes.

"but the low value of the operational reactivity margin restricted further rise of reactor power." That doesn't even make any sense. They mean to say, the reactor wasn't outputting what it should have been with the rods withdrawn.

"The operation of the reactor at the low power level with a small reactivity margin" Why does he insist on saying margin? It doesn't need to be there.

"triggered a trip" Let's try to get inventive with our word selection, please. Triggered an alarm? A warning? An error state? And error status?. A plant trip. Common language in power plants.

"Since water also absorbs neutrons (and the higher density of liquid water makes it a better absorber than steam), turning on additional pumps decreased the reactor power." No mention made of pressures, which have little effect on fluid density anyway.

"All these actions led to an extremely unstable reactor configuration. Nearly all of the control rods were removed, which limited the value of the safety rods when initially inserted in a scram" s I understand things, they actually sent some technicians down to the reactor to pull the rods out entirely; by hand.

"Further, the reactor coolant had limited boiling, but had limited margin to boiling, so any power excursion would produce boiling, reducing neutron absorption by the water." Margin? AGAIN? Simplify to "it was close to boiling". Overly complex, even for a physicist. Yes, it´s rather messy. I do not quite understand why the increased coolant flow rate through the reactor produced an increase in the inlet coolant temperature of the reactor core, I think it should be the other way down.

"The steam to the turbines was shut off, and a run down of the turbine generator began," No need to elaborate on that.

"The diesel generator started and sequentially picked up loads, which was complete by 01:23:43;" The diesel generators picked up the electical load of the pumps and this was completed by.

"it was now primed to embark on a positive feedback loop," Thermal runaway

"However, during almost the entire period of the experiment" Duration

"The reactor was simply being shut down upon the completion of the experiment" Why?

"For whatever reason the EPS-5 button was pressed, insertion of control rods into the reactor core began. The control rod insertion mechanism operated at a relatively slow speed (0.4 m/s) taking 18–20 seconds to travel the full approximately 7-meter core length (height). A bigger problem was a flawed graphite-tip control rod design, which initially displaced coolant before neutron-absorbing material was inserted and the reaction slowed. As a result, the scram actually increased the reaction rate in the lower half of the core." The alternative story I've heard is that in manually withdrawing the rods, they allowed the xeon to escape; causing the subsequent spike. And that it was the rods themselves that melted. Although, having them outside the core makes this unlikely.

"It was not possible to reconstruct the precise sequence of the processes that led to the destruction of the reactor and the power unit building. There is a general understanding that it was steam from the wrecked channels entering the reactor inner structure which' caused the destruction of the fuel casings'; tearing off and lifting, by steam pressure alone, the 2,000 ton upper plate (to which the entire reactor assembly was fastened)."

"excess pressure of vapor." Excessive vapour pressure. I think it should say steam pressure. Vapour pressure is a physic concept for gas-liquid interfaces.

I could go on, endlessly, picking holes in the sentence structure and logic. Instead, I'll simply say, it's too long winded. It routinely tries to make out that things are more complex than they are. Sentences are all over the places and the grammar is not good enough. The guys from Oxford are out there! Watching, bitching. Anyone else for editing the article? I'll do it, but it's a god damn monster. It contains so much useful information, but in a format that is bordering on unaccessible to someone who isn't familiar with the sciences.

"According to another hypothesis, this explosion was of a nuclear nature,[31] i.e., the thermal explosion of the reactor as a result of the uncontrollable escape of fast neutrons caused by the complete water loss in the reactor core. A third hypothesis was that the explosion was caused, exceptionally, by steam." Steam caused the first explosion and the second? The thermal explosion was caused by nuclear reactions? The nuclear reaction heated the water into producing steam? Not same thing.

"According to this version, the flow of steam and the steam pressure caused all the destruction following the ejection from the shaft of a substantial part of the graphite and fuel." What? This is rambling for the sake of it. The cap blew off of the reactor and then the rods blew out? Entirely the opposite of what this sentence suggests. Which suggested the rods blew out and then the cap.

"Parts of the graphite blocks and fuel channels were ejected out of the reactor building"

"However, the ratio of xenon radioisotopes released during the event provides compelling evidence that the second explosion was a nuclear power transient." This is getting boring, even for me. Nuclear power transient? A transient in the levels of nuclear reactivity?

"The nuclear excursion dispersed the core and effectively terminated that phase of the event." What? Rambling?

"Inside reactor 3, the chief of the night shift, Yuri Bagdasarov, wanted to shut down the reactor immediately, but chief engineer Nikolai Fomin would not allow this." Again, no mention of why they ordered this to be so. It was almost certainly due to pressure from the state to keep the reactor functioning; not an unbiased, scientific judgment.

Why didn't the plant have a tower of liquid form moderator ready for this circumstance? I believe even Einstein had bottles of moderator ready to pour on the first pile ever produced.

The article also makes no mention of the official visit the plant had received earlier. Or, the pressure the technicians were under to have it fully operational. Or, the pressure they were under to not embarrass the state with power outages. Placing the entirety of the blame on 'big headed scientists'.

And for anyone about to reply about my own grammar mistakes, this is the discussions page, not an article thousands are using as a reference.

Also not mentioned in the article, but deserving a mention, is that the bible described the star called Wormwood falling to earth and poisoning the rivers, causing bitterness in men. From first hand accounts I've heard that the plant Wormwood is common around Chernobyl.

This article has unfortunately seen a lot of "luvin" from anti-nuclear advocates, attempting to coattrack it to advance their views. You make some excellent points, and I suggest that you be bold and implement some of the changes you suggest. There is nothing wrong with a new editor stepping in and correcting problems. Fell Gleaming^(talk) 23:55, 11 May 2010 (UTC)

Banana equivalent dose

I just reverted an edit that suggested that the average dose of 600 becs of cesium estimated to have been consumed by wild boars living in the Exclusion zone was the equivalent of eating around 4 kg of bananas - the so-called banana equivalent dose. I've done so because it's a false equivalency - potassium-40 is not the same as cesium, as explained quite well here by Geoff Megitt. I think this would be a comparison that it may be best to stay away from, generally speaking but in this article in particular. Kate (talk) 17:51, 2 September 2010 (UTC)

That "BoingBong" opinion piece source obviously has some reliability issues. To point out just a few of the problems:

• In comparing ingested radioisotopes, the radiologic half-life isn't what's important, but rather the biologic half-life -- the amount of time the material stays within the body. For instance, tritiated water has a half-life of 13 years, but a biologic half-life of less than 10 days.
• K-40 (bananas) and C-137 (radioactive cesium) both emit gamma as well as beta.
• While C-137 does emit a higher ratio of gamma to beta than K-40, they are at a much lower energy level (661 kEV vs 1400 MEV)
• For material biologically absorbed, there is no difference between beta and gamma -- they both have a Q factor of one. Their differing penetrating powers only come into play when dealing with external exposures (since, for example, an alpha particle can be stopped by a single sheet of paper).

In short, the BED comparison is simply to show that a 600 bcq/kg figure is extraordinarily low. Perhaps an even more apt comparison would be to use Brazil nuts, because not only are they even more radioactive than bananas, but because their radioactivity is due to radium, its not homeostatically regulated, and more dangerous than either K-40 or C-137. Letting the reader know that eating a kg of Brazil nuts would be more hazardous than eating a steak from one of these 'radioactive' boars is quite important to put the risks in a neutral, unbiased, unemotional light --- something an encyclopedia has a responsibility to do, but a popular newspaper does not. Fell Gleaming^talk 18:28, 2 September 2010 (UTC)

Comparing bananas and boars is bizarre. I think it is more problematic in another way though. You appear to be trying to make an argument that isn't supported by your sources. I thought that wasn't allowed? (Wikipedia:No original research). -- L'ecrivant (talk) 20:26, 2 September 2010 (UTC)

Why is it bizarre? The boar meat is banned as a food source. Bananas are a food source also. Where do you believe the "original research" is coming from? The point is to convey to the reader the fact that these boars are not much more radioactive than a common household food item, rather than feed them vague, alarmist statements. Fell Gleaming^talk 20:37, 2 September 2010 (UTC)

Whether or not bananas are a food source is irrelevant - the important point is the source and action of radioactivity. Potassium-40 is not equivalent to Cesium-137. Kate (talk) 21:15, 2 September 2010 (UTC)

That is certainly true. My concern is that FellGleaming is trying convey his own personal view - "to convey to the reader the fact that these boars are not much more radioactive than a common household food item" - rather than sticking to what his sources say. FellGleaming, do you have a source that makes the argument that you're making? -- L'ecrivant (talk) 21:51, 2 September 2010 (UTC)

Unless we have a reliable source that discusses Chernobyl in terms of banana equivalents, then combining the two ideas in the article is wrong under WP:SYN. --Nigelj (talk) 22:13, 2 September 2010 (UTC)

No. Synthesis is combining two concepts to reach a new conclusion, as that new conclusion is by definition uncited. Using a source that doesn't specifically mention the article subject is not synthesis, unless an editor draws conclusions not specifically mentioned in any source. Writing an encyclopedia entry is all about presenting facts from disparate sources, and WP policy specifically excludes tasks like the collation of numeric data or the creation of numeric tables as being synthesis or original research, even if simple calculations have been performed to reach some of the results. For example, saying "bananas are 1/5 as radioactive as the boars found in South Germany" is not synthesis, as a simple division was used to arrive at the result. However, saying "bananas are 1/5 as dangerous as these boars" is synthesis without a source to back it. Fell Gleaming^talk 22:41, 2 September 2010 (UTC)

Large Areas?

The lede has the uncited claim that "large areas of Ukraine, Belarus, and Russia" needed to be evacuated. However, the article itself only mentions the evacuation of Prypiat and surrounding area. I'm therefore adjusting the lede to match the article text. Fell Gleaming^talk 23:03, 16 September 2010 (UTC)

The cited source was http://www.chernobyl.info/index.php?navID=2, which in turn refers to a UNDP/UNICEF report for its numbers. The report gives the following evacuation and resettlement numbers from 1986-2000:

• Belarus: 135,000
• Russia: 52,400
• Ukraine: 163,000
• Total: 350,400

--Muchness (talk) 05:53, 17 September 2010 (UTC)

Thanks Muchness. The source raises further questions, though. First of all, the source specifically states only the area around Prypiat was evacuated, whereas our text conflates evacuation and resettlement; two very different activities. The source discloses that the majority of those resettled were relocated many years after the accident, sometimes as much as 14 years later. This was apparently done for economic reasons, rather than radiation fears. Further, the source states that the people who chose to stay in affected areas fared better overall than those who resettled -- and those who resettled, but later returned fared best of all.

With all this in mind, quoting resettlement figures without qualification is misleading. Unless we want to devote an entire paragraph of the lede to explaining the situation, we should focus specifically on evacuation numbers, not resettlement'. Fell Gleaming^talk 10:44, 17 September 2010 (UTC)

Inconsistent statistics

The statistics given in the article are inconsistent; direct deaths, for instance, are given at 56, 57, and a russian report at I think 237? It would also be nice if all the stastics, including cases of ARS, deaths from ARS, cancer cases and deaths, etc. were given in a single section for easy reference; they're scattered all over right now. --65.100.114.216 (talk) 16:50, 5 November 2010 (UTC)

Cover plate weight significant difference

there appears to be a difference in cover plate tonnages, the wiki article lists it as 2000t were as the world nuclear org lists it at 1000t. I normally wouldn't mention minor weight issues sizes but this is quiet significantly different. Can anyone find a more reliable 3rd party source as to the weight of the cover plate?

http://www.world-nuclear.org/info/chernobyl/inf07.html From the article "The overpressure caused the 1000 t cover plate of the reactor to become partially detached, rupturing the fuel channels and jamming all the control rods, which by that time were only halfway down. Intense steam generation then spread throughout the whole core (fed by water dumped into the core due to the rupture of the emergency cooling circuit) causing a steam explosion and releasing fission products to the atmosphere. About two to three seconds later, a second explosion threw out fragments from the fuel channels and hot graphite."

I haven't checked for other differences although it appears from the above there maybe others Sirrob01 (talk) 04:40, 2 February 2011 (UTC)

New external link

I have just moved an external link out of the "See also" section to "External links". I was intending to add a new link but due to a note there asking editors to avoid excessive ext. links I am proposing it here.

*{{PDFlink|[http://www.ebrd.com/downloads/research/factsheets/chernobyl25.pdf Chernobyl 25 years on: New Safe Confinement and Spent Fuel Storage Facility]}}. European Bank for Reconstruction & Development

It seems a good update on what is happening re the New safe confinement & Chernobyl Nuclear Power Plant sarcophagus ‎ (to both of which I have already added the link). Please comment !.- 220.101 talk^\Contribs 07:27, 20 February 2011 (UTC)

I agree that it is useful. I would comment that, as I read MOS:APPENDIX guidelines, it seems a better fit in the Further reading section than in the External links section. Wtmitchell (talk) (earlier Boracay Bill) 02:06, 21 February 2011 (UTC)

Technical Inconsistency

In the "Causes" section, there's that bulleted list. Toward the end of the second bullet point, there's a discussion of graphite vs. water as a neutron moderator, along with a link to another article discussing neutron moderation in general terms. Looking at that article, the bullet point seems to be slightly off - graphite would be a "better" neutron moderator than water, not a less effective one. Disclosure: I am not an expert on these subjects by any means, just found this inconsistent. 74.214.62.251 (talk) 00:28, 16 March 2011 (UTC)

Edit request from Rdambrosiaca, 21 March 2011

{{edit semi-protected}} This request refers to the article, "http://en.wikipedia.org/wiki/Chernobyl_disaster"

The Section "Chernobyl: Consequences of The Catastrophe for People and the Environment is a 2009 book published by the New York Academy of Science" is somewhat misleading.

According to a statement on the New York Academy Of Science Website (http://www.nyas.org/AboutUs/MediaRelations/Detail.aspx?cid=16b2d4fe-f5b5-4795-8d38-d59a76d1ef33) it is not authored or sponsored by the NYAS:

"The Annals of the New York Academy of Sciences issue “Chernobyl: Consequences of the Catastrophe for People and the Environment”, therefore, does not present new, unpublished work, nor is it a work commissioned by the New York Academy of Sciences. The expressed views of the authors, or by advocacy groups or individuals with specific opinions about the Annals Chernobyl volume, are their own."

This book is also available from Amazon.com (http://www.amazon.com/Chernobyl-Consequences-Catastrophe-Environment-Sciences/dp/1573317578/ref=sr_1_1?ie=UTF8&s=books&qid=1300740186&sr=8-1)

Rdambrosiaca (talk) 20:50, 21 March 2011 (UTC)Rob D'Ambrosia

Done — Bility (talk) 22:47, 21 March 2011 (UTC)

Accident Time Line

Is the time correct? The article states: "reduction in the output of the power unit was begun at 01:06 on 25 April." This actually occurred during the day (before the power grid delay), so I believe this should read 13:26, not 01:06. Caisson (talk) 04:32, 22 March 2011 (UTC)

Edit request from Hematose, 21 March 2011

{{edit semi-protected}} The sentence in the second paragraph reading: "This event exposed the graphite control rods of the reactor to air, causing them to ignite."

Should read: "This event exposed the heated graphite moderator blocks of the reactor to air, causing them to ignite."

Reasons: Firstly, the control rods are not primarily composed of graphite. Most of each rod is composed of boron carbide. Boron is a neutron absorber that is used to discipline the fission reaction. Carbon is a neutron moderator that slows down neutrons to make more of them available to participate in the reaction; effectively the opposite effect of boron. Some of the rods are tipped with carbon due to a technical complexity that is covered in the RBMK article referenced below, but is unnecessary for an introduction to the accident itself.

Secondly, the moderator blocks contained the vast majority of the graphite in the reactor that caught fire. You'll note that later in this same article, the graphite moderator is specifically referenced, not the control rods.

See here: http://en.wikipedia.org/wiki/RBMK and its associates sources.

Hematose (talk) 19:11, 21 March 2011 (UTC) Hematose

Do you have a reliable source stating this? As it is, I think this rationale would be considered original research. — Bility (talk) 14:49, 22 March 2011 (UTC)

Getting definitive design documents to reference isn't easy without contacts in the industry, but I found this description by the IAEA: http://www.iaea.org/newscenter/features/chernobyl-15/cherno-faq.shtml . I'm a little new to Wikipedia, so I don't know if this is good enough. - Hematose (talk) 12:59, 23 March 2011 (UTC)Hematose

The edit by Cchhrriiss covers this issue now. Should I delete this request? - Hematose (talk) 13:03, 23 March 2011 (UTC)Hematose

If you're satisfied with the edit, the request template can be un-transcluded (did it for you) so that it is removed from the request queue. Thanks for finding that source also, nice job! — Bility (talk) 19:23, 23 March 2011 (UTC)

No mention of the miners

The space under the reactor which was filled with concrete - This area was actually dug out by many miners who were brought in. They had to dig a long tunnel in order to get to the area under the reactor, then dig a "room" originally intended to house cooling equipment, but eventually filled with concrete - all this to stop lava from reaching underground aquifers. —Preceding unsigned comment added by 70.88.250.45 (talk) 01:19, 24 March 2011 (UTC)

1760 PBq of I-131 != 55% of the radioactive iodine in the reactor

" About 1760 PBq of I-131, 55% of the radioactive iodine in the reactor, was released... " seems somewhat misleading; 1760 PBq of I-131 were released; 55% of the radioactive iodine in the reactor was released; but 1760 PBq I-131 is LESS than 55% of radio-I, as there are other I-isotopes. Wda (talk) 11:56, 25 March 2011 (UTC)

Radioactive graphite?

Reading through this article, the first sentence of the "Debris removal" section caught my attention:

The worst of the radioactive debris was collected inside what was left of the reactor, much of it shoveled in by liquidators wearing heavy protective gear (dubbed "bio-robots" by the military); these workers could only spend a maximum of 40 seconds at a time working on the rooftops of the surrounding buildings because of the extremely high doses of radiation given off by the blocks of graphite and other debris.

It was my understanding that nuclear graphite is used as a neutron moderator specifically because it will not form radioactive isotopes under neutron bombardment in a nuclear reactor. How, then, could the graphite blocks ejected from the core "give off extremely high doses of radiation"? Is it simply due to the presence of fuel particles and debris lodged in the blocks following the explosion? Or does the graphite itself absorb or adsorb decay products during normal reactor operation? Graphite isn't mentioned in the radioactive waste article at all, so I'm guessing it's the former. I'm sure the blocks were very radioactive (EVERYTHING was radioactive in that vicinity), but the article definitely implies that the graphite was producing the radiation.

If I'm right, then I submit that this passage needs to be reworded to remove that implication. If I'm wrong, I'm interested to learn! --Lukeonia1 (talk) 05:59, 26 March 2011 (UTC)

Plant layout

Regarding the section on plant layout: What are the units on the left column called "Level"? I looked at the associated reference and couldn't make any sense of it. WriterHound (talk) 05:27, 30 March 2011 (UTC)

I've added a note explaining what I think this column is for. Anyone who thinks this is wrong or a prefers another format (say an asterisked note outside the table) is, as usual, welcome to change this. Britmax (talk) 07:43, 30 March 2011 (UTC)

Missing fuel?

Is the 'missing fuel mystery' a hoax or genuine, and if so, have there been any developments since?--Cancun771 (talk) 10:56, 30 March 2011 (UTC)

Nuclear engineering expertise involved in the article

I'm curious to know if anyone involved in the article, who watches or reverts, copy edits, or adds or adjusts content has nuclear engineering expertise and can parse the dense language involved in the science involved in this article. Thanks. --Moni3 (talk) 20:12, 14 November 2010 (UTC)

After waiting a day without a response, I'm asking because I'm considering rewriting this article. I overhaul articles that need help in areas that spark my interest. This did, for some reason. I have no background in nuclear energy or engineering and I find the science a bit daunting, but I think I can get help with that. I am magnetically drawn to awful events that occur as a result of mass incompetence created or furthered by bureaucracy, and if this isn't a plum example of one, I don't know what is. At least this is the impression I get from the minimal source material I have seen.

I have other concerns for a rewrite. I hate fighting on Wikipedia and only wish to add content and restructure so articles can be best understood by general readers. I'm concerned over POV pushing and have low tolerance right now for pointless battles. The article gets between 8,000-10,000 hits a day and it's on Pending changes, which doesn't thrill me at all. I have no particular POV about nuclear energy although I do have some issues with environmental degradation. But even in articles where I have an emotional stake of some kind, I do my best to reflect only what the sources say about the topic and obtain as many sources as possible.

Ideally, I'd like to rewrite the article in a sandbox off my user page. I generally take action to WP:Be Bold and do it with minimal fanfare, but with an article that gets this many hits and may be a point of contention, not only did I want to gauge interest on the talk page, but invite anyone interested in rewriting the article with the best sources possible (in English) to assist. I'm going to work with FA criteria in mind, although I'm quite sure I won't be nominating the article for FAC for my own reasons. That does not preclude someone else from nominating it, however. I'd like to collaborate with anyone interested who has the best quality sources and writing in mind. If you have nuclear energy experience or can read Russian, I'd love to work with you.

The longest in-depth rewrite I've done took two months. It will take several weeks at least to do this one. If feedback is minimal or favorable, I'm going to get as many sources as possible and read through them to reconstruct the article. Basically I'll be starting from scratch. Please let me know your thoughts. Thank you. --Moni3 (talk) 16:16, 15 November 2010 (UTC)

Hi, I have this page watchlisted and noticed your message here. There doesn't seem to be much activity here, so your rewrite is unlikely to fall victim of some edit war. The controversy around the topic seems to be focused mainly on the two versions noted in the text as well as the appraisal of damage the accident has caused to people and environment and of dangers nuclear power represents. The article looks okay-ish to me, if somewhat long-winded and some parts appear kind of just piled up. So, if you're willing to rewrite the article into a clear and concise unit, I'm all for it. Unfortunately, my knowledge of both the accident details and nuclear physics is minimal, so the only thing I can offer to an experienced editor are my Russian and German skills (in case some information from those two Wikipedia articles or a Russian source is needed). --illythr (talk) 17:45, 15 November 2010 (UTC)

The whole technical aspect of the article would be greatly improved with a simple explanation of the basic operation of the RBMK reactor system. The use of graphite, non-enriched uranium, the function of the graphite moderator, that function of the water as a coolant and neutron absorber and an explanation of what "Positive void coefficient" is, as well as the design of the control rods. Once this is done a lot of repeated explanations could be removed from the main body of the article, and the article would be less dense and clearer overall. —Preceding unsigned comment added by 206.248.135.100 (talk) 02:08, 4 April 2011 (UTC)

Rewrite in process

In my sandbox here. I'm still interested in anyone who may have expertise in nuclear engineering. Thanks. --Moni3 (talk) 19:34, 20 November 2010 (UTC)

Suggestion on the second paragraph and questions on the word "spike"

I wonder if the sentence in the second paragraph describing the cause of the events can't be improved with more or different details, chronology, causality, or presentation, to match the rest of the article. Right now (April 4, 2011) the article states, "There was a sudden power output surge, and when an emergency shutdown was attempted, a more extreme spike in power output occurred, which led to a reactor vessel rupture and a series of explosions." I think that it should be mentioned that these "surges" and "spikes" are of thermal power -- not input electric or output electric power.

A reading of this article's Reference #28, the World Nuclear Organization's http://www.world-nuclear.org/info/chernobyl/inf07.html website's events sequence ( http://www.world-nuclear.org/info/chernobyl/inf07app.html ), subjectively seems to characterize the thermal power anomaly(ies) as more of a "continued" rise and surge, until a runaway situation is reached. The log in the sequence (not the Timeline) shows "At 01:23:43, the power excursion rate emergency protection system signals came on and power exceeded 530 MWt and continued to rise." After this what is mentioned is the rupture of fuel elements, then increased steam and pressure changes until the next entry by Chief Reactor control engineer at 1:24 (17 seconds later) indicating "severe shocks." Would this 17-second increase with no short-term decrease qualify as a "spike?"

I wonder how other contributors and readers view this.

DonL (talk) 20:01, 4 April 2011 (UTC)

Gigantic revert

In this edit of February 16, 2011, the page was reverted (rvv) to this version of September 12, 2010, thus discarding five months of edits. I suspect that this was a mistake, and venture to guess that the last month of improvements, which were applied to the September 2010 version, has resulted in something inferior to the state the article was on in early February 2011.  --Lambiam 07:30, 14 March 2011 (UTC)

Specifically, I recommend reverting to revision 413986699 as of 01:33, February 15, 2011. While that will discard one month's worth of edits, the alternative is to have five months' worth thrown away.  --Lambiam 07:48, 14 March 2011 (UTC)

Is it not possible for somebody to go through the last months worth of edits and see what of substance was added and re-add it? If it was just syntax and formatting it doesn't matter but its possible people added new sources and information that could be easily added to the latest version - would just take a little time. 202.175.121.154 (talk) 08:47, 14 March 2011 (UTC)

It would be a lot of work, but it is not impossible; we would still need to revert first to the September 2010 February 15 version.  --Lambiam 09:22, 14 March 2011 (UTC)

No we wouldn't - revert now to 15 Feb version, then look back in old versions since then for any useful content to add.--Pontificalibus (talk) 09:37, 14 March 2011 (UTC)

Corrected.  --Lambiam 10:19, 14 March 2011 (UTC)

http://en.wikipedia.org/w/index.php?title=Chernobyl_disaster&action=historysubmit&diff=414213866&oldid=414011200 does not seem like it would take "a lot of work" to me. 198.96.35.248 (talk) 11:16, 14 March 2011 (UTC)

I concur with pontificalibus, I think the best option is to revert to the February 15 version and sift through the edits since then to see what can be added. I think we should proceed with the revert as the pre-Feb 16 article is in all probability the more useful version. --Basalisk 12:36, 14 March 2011 (UTC)

The question is would it be more work to manually alter the current version with the differences caused by the revert or to revert and manually add in the changes since 15th Feb. Looking at the diffs I'm not sure that a revert is the best option.....

--IanOfNorwich (talk) 12:56, 14 March 2011 (UTC)

OK here we have the diff from the bad revert till now:[2] compare with the diff caused by the bad revert:[3]--IanOfNorwich (talk) 13:02, 14 March 2011 (UTC)

Seems to me that there is less red on the diff of the bad revert than between the revert and now. That means the best route is NOT to revert and try to work back in the red bits of [4]--IanOfNorwich (talk) 13:08, 14 March 2011 (UTC)

On that basis I'm going to remove the notice at the top of the page as this is likely to be a hot topic at the moment and it would be nice to make the page 'editable' again. It still leaves the restoring the content lost by the bad revert - I'll try to return and do some in the near future until then:

PLEASE HELP THIS ARTICLE BY MANUALLY RESTORING ANY GOOD CONTENT LOST IN THIS REVERSION - [5].

--IanOfNorwich (talk) 13:15, 14 March 2011 (UTC)

I have not looked closely at the article history or content. As I indicated above, this is something which seems to have come up as what appeared to me at the time to be a minor vandalism revert. My guess would be that the best course would be to restore the article to its state as of this version, which immediately preceded the problem revert, and work forward from there. I'll be happy to pitch in and try to help, but I don't know the topic any better than any other uninvolved editor and my guess is that editors more knowledgeable about the topic would do a better job than I on this. Let me know if I can do anything to help. Wtmitchell (talk) (earlier Boracay Bill) 22:27, 14 March 2011 (UTC)

Hi Wtmitchell, Have you compared the differences caused by the revert with the differences from after the revert till now?--IanOfNorwich (talk) 09:30, 23 March 2011 (UTC)

Done; more or less. There wasn't really all that much good stuff lost in the bad revert. I've restored all that I think is significant and worth restoring. There are still crumbs if anyone fancies doing more. Please DON'T anyone even think about reverting to before the bad revert now.--IanOfNorwich (talk) 21:34, 27 March 2011 (UTC)

Restore completed. All remaining items of value are restored. The only item of significance that I didn't restore was a reference at the end of the second paragraph. The reference reads:

"Geographical location and extent of radioactive contamination". Swiss Agency for Development and Cooperation. (quoting the "Committee on the Problems of the Consequences of the Catastrophe at the Chernobyl NPP: 15 Years after Chernobyl Disaster", Minsk, 2001, p. 5/6 ff., and the "Chernobyl Interinform Agency, Kiev und", and "Chernobyl Committee: MailTable of official data on the reactor accident")

...and I can't find the document in question at the link provided. Fuzzypeg★ 02:08, 8 April 2011 (UTC)

Conflicting tone in article

Apologies if I'm reporting this in the wrong place... but I noticed that there are different tones used in this article based on whether an anti-nuclear group or a neutral or pro-nuclear group is being quoted.

For example, on the positive side...

"This report is not free of controversy, and has been accused of trying to minimize the consequences of the accident."

"Professor Wade Allison of Oxford University (a lecturer in medical physics and particle physics) gave a talk on ionising radiation Nov 24, 2006 in which he gave an approximate figure of 81 cancer deaths from Chernobyl (excluding 28 cases from acute radiation exposure and the thyroid cancer deaths which he regards as "avoidable"). In a closely reasoned argument using statistics from therapeutic radiation, exposure to elevated natural radiation (the presence of radon gas in homes) and the diseases of Hiroshima and Nagasaki survivors he demonstrated that the linear no-threshold model should not be applied to low-level exposure in humans, as it ignores the well-known natural repair mechanisms of the body.["

in these parts of the article a positive view of chernobyl is described as "closely reasoned" and that a conclusion was "demonstrated". a criticism is described with "accused".

On the negative side...

"Another study claims possible heightened mortality in Sweden." "In Europe, the IPPNW claims..... They also claim that several hundreds of thousands of the people who worked on the site after the disaster are now sick because of radiation, and tens of thousands are dead."

why are these "claims"? if they are disputed, what counterevidence is there? why is it not possible to verify whether a person did or did not die?

......

"Other studies and claims" - Why are the studies which are not disputed lumped in with the claims which are disputed?

"However, concern has been expressed about the methods used in compiling the Greenpeace report." - What concern? By who?

"The methodology of the Chernobyl Forum report has been disputed by some advocacy organizations opposed to nuclear energy, such as Greenpeace and the International Physicians for Prevention of Nuclear Warfare (IPPNW), as well as some individuals such as Elisabeth Cardis of the International Agency for Research on Cancer" - Why does this need "some" before advocacy organizations and "some" before individuals? It's obvious that 100% of individuals and 100% of organizations don't agree on anything.

" It will be impossible to attribute specific deaths to Chernobyl, and many estimates indicate that the rate of excess deaths will be so small as to be statistically undetectable, even if the ultimate number of extra premature deaths is large." - What "many estimates" are being referenced in this sentence? Earlier the article states that 31 people died as a result of the disaster. Is that not a statistically detectable number?

"Furthermore, the effects of low-level radiation on human health are not well understood" - Except by the multiple scientific research studies that are referenced through this article?

"An increased incidence of thyroid cancer among children in areas of Belarus, Ukraine and Russia affected by the Chernobyl disaster has been firmly established as a result of screening programs and, in the case of Belarus, an established cancer registry. The findings of most epidemiological studies must be considered interim, say experts, as analysis of the health effects of the disaster is an ongoing process." - Which "experts" have said that?

"On the other hand, most of those affected received relatively low doses of radiation; there is little evidence of increased mortality, cancers or birth defects among them; and when such evidence is present, existence of a causal link to radioactive contamination is uncertain." - Later in the page a variety of evidence is linked to, some of which concretely shows a link.

"On the basis of current coefficients, however, one cannot assume that calculation of individual exposure doses resulting from fallout would not induce measurable rates of chromosome aberrations." - This sentence is saying that we can't be sure that calculating the number of individuals who were exposed would not induce measurable rates of aberrations? What? Double negative much?

"Late in 1995, the World Health Organisation (WHO) linked nearly 700 cases of thyroid cancer among children and adolescents to the Chernobyl disaster, and among these some 10 deaths are attributed to radiation. However, the rapid increase in thyroid cancers detected suggests that some of it at least is an artifact of the screening process. Typical latency time of radiation-induced thyroid cancer is about 10 years, but the increase in childhood thyroid cancers in some regions was observed as early as 1987. Presumably either the increase is unrelated to the disaster or the mechanisms behind it are not well understood." - Because there was a dramatic spike in cancer, that could indicate it was unrelated to radiation? What? —Preceding unsigned comment added by 64.81.170.239 (talk) 23:23, 15 March 2011 (UTC)

The cancer increase would not be expected until about 10 years later, but it occurred much sooner. Hence, it could be a coincidence, and something else was causing the cancer; or more cases were diagnosed because people were looking harder for thyroid cancer; or it *was* caused by the radiation but the mechanism of causation is not understood. Or some combination thereof. This actually does make sense.Megalophias (talk) 00:58, 17 March 2011 (UTC)

Many of your concerns are backed up by WP guidelines: see WP:SAY, WP:ALLEGED, and more broadly, WP:NPOV. The article should indeed take a more neutral tone. I'll have a look through and see if I can improve some of the problems you've highlighted. Fuzzypeg★ 02:18, 8 April 2011 (UTC)

It looks as though most of your concerns have already been addressed. I've fixed up whatever I could see that remained. Fuzzypeg★ 02:58, 8 April 2011 (UTC)

Potential steam explosion

I just thought the "ahem" in the edit summary contained just the exquisitely perfect amount of condescension and scorn. Well done. The object of the summary was well-expressed.

There wasn't any more information in it, was there? --Moni3 (talk) 19:56, 10 April 2011 (UTC)

Moni3, this really seems to be talking about the previous subject. Would you mind if I moved it up there so we only have one thread? I'll combine the titles, too. Thanks! — UncleBubba ^{( T @ C )} 20:09, 10 April 2011 (UTC)

Criticism of Greenpeace report

The article refers to a statement by Mikhail Balanov, Scientific Secretary of the Chernobyl Forum, criticising the 2006 Greenpeace report. He said (as reported in Der Spiegel), "Peer reviewed science only really started developing in Russia and the Soviet states after the Soviet Union collapsed" ... "If you want to get some serious conclusions from the data, it has to be in peer reviewed papers. Unfortunately none of the studies cited in the new report have been peer reviewed ... . It relies on bad science."

But that's clearly not true. Looking at the report, the majority of cited sources seem to be from peer reviewed journals, many from post-Soviet countries, but a good proportion from Western medical and scientific journals such as Nature, Lancet, Clinical Endocrinology and Endocrine Surgery, The Hematology Journal, British Journal of Haematology, etc., etc., etc.. The second most numerous type of source is proceedings of scientific conferences, such as the 2001 European Congress on Radiology, or the 10th International Congress on Anticancer Treatment, or official reports of scientific or government groups, such as the State Committee of Statistics of Ukraine.

Balanov's statement that "none of the studies ... have been peer reviewed" is entirely false. Fuzzypeg★ 05:48, 12 April 2011 (UTC)

Units of Radiation Incorrect

Currently the article gives radiation doasge levels in Roentgens, however this is not the SI unit for radiation and shouldnt be used. indeed the links from this page to other pages eg the levels of nuclear incidents use Sieverts as the unit of dosage (appropriately). I therefor suggest that these figures be converted. Unforunately i dont know how. —Preceding unsigned comment added by 195.89.27.224 (talk) 13:14, 15 March 2011 (UTC)

I agree. I just converted the main chart. The conversion rate is 1/100. Jeff Carr (talk) 19:07, 15 March 2011 (UTC)

Was it in roentgens or rem? Only the latter are directly convertible to Sv. beefman (talk) 09:24, 26 March 2011 (UTC)

It now states that Sv/h is an S.I. unit. I understand the use of Sv/h but the claim that it is an S.I. unit should i.m.o. be removed since it is not true. — Preceding unsigned comment added by Wilberth (talk • contribs) 13:13, 18 April 2011 (UTC)

Sieverts are SI-derived units. My concern is that somebody took Roentgens and converted to Sv by multiplying. Conversion is generally only possible by columns of the following table unless more information is given.

activity	absorbed energy	dose
curie (Ci)	roentgen (R), rad	rem
bequerel (Bq)	gray (Gy)	sievert (Sv)

beefman (talk) 20:25, 18 April 2011 (UTC)

Assuming the original measurement was gamma & beta only, it looks like the dose may be approximated with 1 R = 9.3 mGy = 9.3 mSv. See here under "Roentgen equivalent physical". beefman (talk) 23:22, 18 April 2011 (UTC)

Giving structure to section Chernobyl disaster#Assessing the disaster's effects on human health

The section as it stands is long and meandering, with no clear structure, making it difficult to read and difficult to maintain (if one has new material to add, where does one add it?). I propose adding subheadings. The controversial nature of estimating the health effects should be explained at the beginning, as it is an important preliminary to understanding the various claims regarding any area of health impact. I therefore propose adding the following subheadings, rearranging the info to fit:

• Controversial nature of assessments (discuss general difficulties [see e.g. "Chernobyl: The Decade of Despair" for a good presentation of the controversy], present major reports and their broad findings)
• Radiation syndrome
• Thyroid cancer
• Leukaemia
• Solid cancers
• Genetic defects
• Cognitive defects
• Mental health
• (etc.)

Thoughts, opinions anyone? Fuzzypeg★ 22:11, 13 April 2011 (UTC)

Image of dog with dipygus

This stuffed dog may be in a Chernobyl museum, but I can't find anything stating the deformity was due to the Chernobyl accident, or that rates of dipygus in animals increased as a result of the accident. The reference in the caption is a bit of a stretch. The authors report only that they "designed and administered a dietary and activity survey to 344 women in Polissia". beefman (talk) 00:16, 11 April 2011 (UTC)

They report more than that. they report that "elevated rates of birth defects in contaminated compared to uncontaminated regions suggest that exposure to radiation in utero might impact development and that chronic radiation exposure might represent an underestimated risk to human health", and conclude that chronic exposure of women to low-dose radiation "might contribute (especially synergistically with alcohol consumption and micronutrient deficiencies) to higher prevalence of birth defects in areas of Ukraine with high levels of radiation contamination compared to uncontaminated areas."

That's all just from the abstract. I haven't read the article itself. I reckon I can find other sources that concur... Fuzzypeg★ 23:01, 20 April 2011 (UTC)

I see what you're on about. You're questioning whether it's appropriate to show this specimen from the Chernobyl museum to illustrate the statement that levels of mutations have increased in animals and humans. Because... you haven't seen proof that this particular case of dipygus actually resulted from irradiation, or that digypus in general increased in irradiated areas. The caption of the image doesn't specifically mention dipygus, though, and merely mentions 'mutation'. There are numerous scientific papers linking Chernobyl fallout with greatly increased incidence of congenital deformities, and ionising radiation is a known cause of dysmelia, so is there really any reason to doubt that this particular dog's deformities were radiation-related? The museum clearly thought they were...

I guess there's a small chance that this particular dog's deformities were purely spontaneous and unrelated to radiation, and we can never conclusively prove one way or the other. But then, that will always be the case. No individual instance of congenital deformity can ever be conclusively linked to radiation exposure.

I hope I've understood you correctly... Fuzzypeg★ 02:07, 21 April 2011 (UTC)

Belarus discriminated

In section "Effects" from the timetable of areas of contamination it follows that Russia suffered more that Belarus. Please, look at numbers you've provided. People in Belarus are dying everyday, because 30% of its territory is radioactive now, not Russian or Ukrainian.

No, that doesn't necessarily follow. More Russian than Belarussian land received low dose contamination, but according to the table more Belarussian than Russian land received very high dose contamination. You do raise a valid point, though. Whoever added the table to wikipedia added colours from red to green, in a manner that implies the reddest one has the worst radiation. If we're going to have these colours then the table should be reorganised with Belarus at the top with darkest red, then probably Ukraine next, then Russia. The order will then differ from the IAEA's table from which it is sourced, but the data is the same, so it shouldn't matter. I'll change it now. Fuzzypeg★ 22:47, 20 April 2011 (UTC)

Chernobyl Disaster - The Severe Days film

I noticed this film when someone tried to use it as a reference. I do not know if it should be included in the external links, so I thought that I would see what other people think. The film was allegedly shot by Russian filmmaker Vladimir Shevchenko soon after the accident. He supposedly died as a result of his radiation exposure. I do not use the words "allegedly" or "supposedly" to insult the memory of this person or his family, just to note that there is a lack of reliable sources to verify what happened, at least on the Internet. I am having trouble finding a reliable source who has the film. Most of the search results are YouTube and Dailymotion users. In addition, there are different versions of the film. I call the most common version the "Internet" version. It has no sound, but someone has added text to it. This person claims that his or her father, a nuclear scientist, met Vladimir Shevchenko in the hospital after he made the film. It also has some commentary about what is seen on the film. Someone else has made a version with no text, but music has been added. If I had to choose between them, I would choose the music version, as the other one makes a couple of claims that are obviously false, or at least misleading, and additional claims that cannot be easily verified. However, I would prefer to get the original version of the film, if possible.

• "Internet" version
• "Music" version

-- Kjkolb (talk) 21:33, 23 April 2011 (UTC)

English search gives mostly bullshit. I have no time now to weed away all video/download chaffsites, but Russophones may do search for "Хроника трудных дней" (film title) Владимир Шевченко (director) Виктор Крипченко Владимир Таранченко (cameramen)

Below is a piece from livejournal:

• --

Вместе с Шевченко над фильмом "Чернобыль. Хроника трудных дней" работало ещё два оператора: Виктор Крипченко и Владимир Таранченко. Все трое были Лауреатами Государственной премии СССР в области литературы, искусства и архитектуры. Шевченко - посмертно, т.к. умер 30 марта 1987 года. То есть, почти через год после Чернобыльской аварии. Кстати, умер в возрасте 58 лет, что не доказывает то, что умер режиссёр от облучения. Так что безграмотные заявления о том, что оператор (на самом деле режиссёр) умер через неделю после съёмок, выдаёт в вас, о малоуважаемый блоггер, безграмотность, лень и желание срубить "бабла" на чужих костях.

Ксати, Виктор Крипченко получил "НИКУ" за Лучшую операторскую работу в неигровом кино. Съёмочный перод фильма был 100 дней.

На съёмки группа выехала только 14 мая. Вот состав группы: режиссер Владимир Шевченко, операторы Виктор Крипченко и Владимир Таранченко, механик Валерий Башкатов, звукооператор Александр Королев, водители Павел Сорока и Василий Максименко

• --

Ladnadruk (talk) 15:36, 28 April 2011 (UTC)

Inconsistent information about the experiment

In section "Attempted experiment", the article states that:

"Chernobyl's reactors had three backup diesel generators. Each generator required 15 seconds to start up but took 60–75 seconds to attain full speed and reach the capacity of 5.5 MW required to run one main cooling water pump." (this info is allegedly taken from a book by Medvedev, 1990).

In a following section, the article says something different:

"At 1:23:04 a.m. the experiment began. Four (of eight total) Main Circulating Pumps (MCP) were active. The steam to the turbines was shut off, and a run down of the turbine generator began. The diesel generator started and sequentially picked up loads, which was complete by 01:23:43. During this period, the power for the four MCPs was supplied by the turbine generator as it coasted down."

There are two significant inconsistecies:

1. The first sentence says that there are three diesel generators, each required to run a MCP. The second says that four MCP were powered by one ("the") diesel generator.
2. The first sentence says that 60-75 sdeconds are needed to attain full speed, while the second says that 39 seconds after the beginning of the experiment the diesel generator completely "picked up loads".

We need to be more accurate. Is someone willing to explain what is the truth? Paolo.dL (talk) 13:48, 27 April 2011 (UTC)

lava radiation

Please see my question at File talk:Levels of radioactivity in the lava under the Chernobyl number four reactor 1986.svg --Dweller (talk) 19:18, 28 April 2011 (UTC)

Number of deaths caused by the disaster

The numbers of deaths quoted by various sources in the section 'Assessing the disaster's effects on human health' differs by several orders of magnitude. Is the source behind the highest quote (985,000 deaths) generally accepted? Or are there are notable sources questioning this number? Whether or not this number is supportable, I think it would be useful with some kind of explanation to explain the huge spread in the quoted number of deaths. Lklundin (talk) 20:49, 15 March 2011 (UTC)

Officially, the death toll is 31. Soviet authorities narrowly defined deaths caused by the disaster and stopped counting at 31. --Moni3 (talk) 20:56, 15 March 2011 (UTC)

The highest quote is reviewed here. I would be cautious about giving it too much weight, but it is published in a journel so a mention should be made. The greenpeace figure is presented reasonably well. The UN number should get the most weight. The uncited bullet points don't seem to fit in at all. A bigger problem is the lead which currently says "from possibly 4,000 to close to a million" which is vague to the extreme. I would suggest presenting the UN/WHO figure here (maybe with in a sentence suggesting that some dispute this number). A 2005 source suggests a total of up to 4000 people could eventually die, but as of mid-2005, there are fewer than 50 deaths.[6] AIRcorn (talk) 03:00, 17 March 2011 (UTC)

I moved that sentence up to lead simply because the previous version had failed to mention any direct figures. I agree that a more suitable estimate would be appropriate, given that the higher numbers don't hold as much water. "While estimates of the total number of deaths attributable to the accident vary enormously, the UN and WHO put this figure around 4000."Geoff (talk) 04:25, 17 March 2011 (UTC)

The WHO is an agency of the UN so and does not really work (WHO should be fine by itself). I think it needs to be made clearer that the estimates are potential deaths and that it is up to 4000. "While estimates of the number of deaths potentially resulting from the accident vary enormously, the World Health Organization suggest this could reach 4000." AIRcorn (talk) 06:37, 17 March 2011 (UTC)

Those low figures are "immediate deaths", there are houndred thousands of "delayed deaths" caused by radio-typical cancers. There are contaminated areas all over Europe, even Westeurope, in which hunting, agriculture, living or cattle-breeding is still impossible, and for the next 300 to 500 years. People, whose regions were hit by the Chernobyl fallout clouds, still die of radio-typical cancers today; amongst them recently a German Green high-ranked politician. -- 91.35.55.103 (talk) 10:18, 17 March 2011 (UTC)

Can you substantiate this in any way? It seems strange to me that the health effects should last longer than the radiation (e.g. thyroid cancer caused by I-131 tripling ten years later, when it has about a week of half life), but I only read the Greenpeace stuff cursorily. Ketil (talk) 12:40, 17 March 2011 (UTC)

While the Greenpeace articles may be a less accepted by the scientific community as a whole, they are a well-known published source and can't be ignored. Why don't we incorporate those reports by name: "While estimates of the number of deaths resulting from the accident vary enormously, the World Health Organization suggests this could reach 4000. Greenpeace, alternatively, has recently published a report placing this figure at 200,000 lives or more."Geoff (talk) 19:13, 17 March 2011 (UTC)

Could we shorten it: "Estimates of the number of deaths resulting from the accident vary enormously; the World Health Organization suggest it could reach 4,000 while a Greenpeace report puts this figure at 200,000 or more." WHO and Greenpeace wikilinked of course. AIRcorn (talk) 02:01, 18 March 2011 (UTC)

The passage in the intro "Estimates of the total number of deaths attributable to the accident vary enormously, from possibly 4,000 to close to a million." refers to an IAEA report which includes the 4,000 figure, but that is the expected number of new thyroid cancer cases due to the disaster, NOT deaths (99% survival rate). The report estimates "only" 2,200 direct deaths, but one would have to do the math on the (relatively small) additional # of deaths due to cancers. —Preceding unsigned comment added by 77.248.57.114 (talk) 08:42, 18 March 2011 (UTC)

Not sure where the 2,200 comes from as the links in the article are dead. This from IAEA says estimated deaths are 4,000. The 4,000 cases of thyroid cancers is a seperate figure. AIRcorn (talk) 14:08, 18 March 2011 (UTC)

Currently, the first number of directly related deaths is "more than fifty" in the first sentence of the forth paragraph. However the page it links to lists only thirty direct deaths. I propose this inconsistency should be addressed by changing this page to read "more than thirty" rather than "more than fifty." Nathanfunk (talk) 16:36, 22 March 2011 (UTC)

The real number of deaths expected that has been used by the IAEA in 2006 is 9000. 4000 from the group of 600,000 most directly affected by the accident, and the a further 5000 from the peripheral population. Fred Mettler uses these numbers, while the official report states that "among the 5 million persons residing in other ‘contaminated’ areas" where doses were lower, the report projected cancer mortality "increases of less than one per cent", which is actually less than 50,000. These numbers are very speculative, and analysis is difficult for a number of reasons.

I changed the text to reflect these IAEA numbers. They are there in the text of the report, and referenced to IAEA sources. I also added some material on the difficulties of collecting accurate coalatable statistics in post-Soviet Ukraine.

Focus on Thyroid cancer and Iodine 131 is a bit misleading because the real long term health effects would result from the release of smaller amounts of Cessium 137 and Strontium 90. The latter being a causal agent in causing leukemia. The long term effects of these relatively smaller amounts of contaminants being released is far harder to track.

Personally, I think the article would be a lot cleaner if the two sections relating to official reports from the UN and other sources was separated from the counter-narrative of the objectors like Greenpeace. I also think the representation of the official version and the counter narrative is a bit biased. I think the article should be more bland in its representation of the facts. The IAEA can speak for itself, and Greenpeace can speak for itself, and people should be allowed to judge from themselves, which they will anyway." —Preceding unsigned comment added by 206.248.135.100 (talk) 01:55, 4 April 2011 (UTC)

Claim of cover-up regarding sickness/death statistics

I'm taking the following from Discovery Channel's excellent documentary The Battle of Chernobyl (time through video 1:16:50):

Narrator: "The Deputy of the Supreme Soviet discovered the systematic cover-up of the true consequences of Chernobyl when the Soviet empire dissolved in 1991. Taking advantage of the anarchy in the country, she managed to get her hands on a copy of top secret documents: 600 pages of a report to the Central Committee, written while the battle of Chernobyl was still raging." Alla Yaroshinskaya, former Deputy of the USSR Supreme Soviet, speaks (with translated voice-over): "When I read these documents I discovered everything happened differently. I realised just how huge a lie the Party leaders told. Decree number 12 stated that on the 12th of May 1986, 10,198 people had already been hospitalised; 345 showed signs of radio lesions. Yet at the same time they were telling us everything was fine, that it was nothing serious, and I realised the scope of the lies."

Narrator continues: "According to Alla, another passage reveals that authorities had arbitrarily changed the standards, multiplying by five what was considered the acceptable dose of radiation for the human body." Alla Yaroshinskaya continues: "When they raised the standard, suddenly people were miraculously cured. They were released from the hospital and sent home. It was criminal."

This seems like fairly relevant information, probably disputed by the Russian government, but it comes from a respected source who in the video produces a facsimile copy of the alleged documentation, with signatures. Yaroshinskaya's brief bio can be found here. Fuzzypeg★ 12:54, 7 April 2011 (UTC)

The UNSCEAR projection of 4000 deaths due to cancer is also discussed in The Battle of Chernobyl (starting at 1:18:30): Narrator: "In late August 1986 the first international conference assessing Chernobyl took place behind closed doors. It was presided over by Hans Blix. No journalists or outside observers were admitted into the amphitheatre. The Russian delegation was led by Legasov, the man who'd been in charge of the governmental commission during the battle of Chernobyl." Mikhail Gorbachev speaks (with translated voiceover): "When we put him in charge of preparing the report for the IAEA, we gave hime the duty of reporting everything. He came up with a very detailed report that put everyone in a state of shock." Narrator: "Legasov spoke for three hours. His report concluded that in the decades to come, about 40,000 deaths from cancer caused by Chernobyl were to be expected. The Western world refused flat-out to accept this estimate, which spurred a genuine East-West negotiation." Hans Blix speaks: "These are theoretical calculations based upon the Hiroshima model, that you say that if you have a certain radioactivity, you know from Hiroshima that the long-term effect is so-and-so many would die from it. And if you then increase it by ten-fold, you assume that it will be ten-fold. Well, that is the calculation, ah, this is not I think exact, this is not empiric." Narrator: "There again, the figures were surprisingly flexible. By the end of the conference, people were no longer talking about 40,000, but rather of 4,000 probable deaths. Nearly 20 years later, in September 2005, this figure became the official death-toll of the disaster. The staunchest opponents to the Soviets' policy of transparency were the French, who went as far as to deny that the radioactive cloud passed over their country." At this point we have the voice of Prof. P. Pellerin, French Minister of Health, saying to the effect that there's no reason to worry, the wind is blowing the other way, there's no danger to health (with subtitles). Narrator: "20 years later, in France, and especially in Corsica, cases of thyroid cancer of the same nature and severity as those around Chernobyl are being reported." Fuzzypeg★ 13:30, 7 April 2011 (UTC)

Please note that there is a probably more complete version (duration 1:32:58) here or at Google. I didn't check which scenes are missing in the first one, but the second definitely contains the disputed interview with Vasili Nesterenko on the possibility of a megaton-range explosion.--SiriusB (talk) 13:16, 19 May 2011 (UTC)

Request for comment

In Ukraine there are currently demonstrations and (even) hunger strikes by former Chornobyl cleanup workers against a government decided of late September to cut there pensions. Read more here or/and here. Should/can this be mentioned in this article (or one of the related Chernobyl articles) or is it to "newsy" or insignificant? — Yulia Romero • Talk to me! 18:12, 8 December 2011 (UTC)