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This is an old revision of this page, as edited by 76.246.235.134 (talk) at 23:04, 13 June 2011 (→‎NBC: new section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

There are discussions related to the nuclear accident both here and at Talk:Fukushima I Nuclear Power Plant


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Meltdown in number 2 and 3 reactors

According to this http://www.abc.net.au/news/stories/2011/05/24/3225645.htm "The latest announcement means all three reactors with active fuel inside the Fukushima plant, north-east of Tokyo, are believed to have suffered meltdowns after the March disaster."

Should this be reflected in the article? --Zaphood (talk) 21:08, 24 May 2011 (UTC)[reply]

deleted significant fact because not supported by reference: Yonoromi(sic) line

This was in the section on the 5&6 reactors. Apparently it has been in there quite some tinme. I couldn't seem to track down, through comparing histories, when and who made the change, so I gave up on that. Here it is:

External power was partially restored to unit 5 via transformers at unit 6 connected to the Yonoromi power transmission line on 21 March.(ref name=NISA40/)

The citation does not mention Yonomori. The Yonomori Line is not one of the major transmission lines, but this would be an important piece of the puzzle about backup power supply if it can be substantiated. Backup power is of course a key to this disaster. There is a tiny distribution line that leaves the plant from up the cliff and exits the plant along the first base foul line of the baseball field. This line goes to Yonomori, and so I assume that is the Yonomori line. It terminates in a tiny distribution substation, that has another line that heads east and cross-county. ( Martin | talk • contribs 15:45, 2 May 2011 (UTC))[reply]

It was mentioned by name somewhere, i put it in. I have hunted a bit for it but havnt found it and dont have sufficient time now to hunt further. It was in a release at the time the power was restored but I couldnt find it looking through the obvious ones at the right sort of time. Sandpiper (talk) 22:30, 4 May 2011 (UTC)[reply]
Sure. References help. Even they can contain unverified information. Theanphibian found transmission line names in the 2003 TEPCO Annual Report, in Japanese and posted them here. (!) The Yonomori line's involvement is an open issue. It is a Tohoku line I am convinced.( Martin | talk • contribs 16:27, 6 May 2011 (UTC))[reply]
What do you want to know about the Yonamori line? See page 3. #27 pylon of the 66000v #2 Yonamori line collapsed by the earthquake. [1] [2] [3] Hope this information is helpful. Oda Mari (talk) 17:59, 6 May 2011 (UTC)[reply]
Thanks! There is some discussion on the first of these documents, 23032202, page 3, at Commons.wikimedia. But if pylon #27 on the Yonomori line fell down, isn't that a bad thing? Checking, but here is a questioning. Ah! 66kV. That's new. ( Martin | talk • contribs 16:31, 7 May 2011 (UTC))[reply]
---
Thank you for the references. They do not dispel the questions, unfortunately. The question about the Yonomori line (the night forest line, in translation) is, apparently, how it relates to Units 5&6. Units 5&6 are a somewhat of a side issue. (1) The story would be clearer if the 500 kV Futaba line had pylon #27 down, and tiny 66kV Yonomori came to the rescue; but that is not the story. There is no report of a problem with the Futaba Line. (2) If Yonomori comes from Shin-Fukushima, why send power on a small line with a tower down rather than a big line with no problems? (3) I count the 30th pylon on the Yonomori line by the baseball field, so 27 would be somewhat to the south of the plant. One of the pictures in one of the article you referenced had red and yellow circles around the second last pylon, near Unit 5&6. Maybe the pylon numbering is not intuitive. (4) I forgot that there were small towers by Units 5&6. I cannot follow that tower string more than a few towers. (5) This confusion is bothersome. (6) One article you referenced says that the towers were out of range of the tsunami. I agree. Many, maybe half, the towers on on hills, and most of the rest are inland. Very few (three?) are "at risk", and towers are mostly empty space, and have foundations. Three would need to be knocked out for three transmission lines to be disabled. (7) One article did have a picture of men in the field and a story about a downed tower. Thank you. Will follow this. If you find more, please do post. ( Martin | talk • contribs 05:11, 8 May 2011 (UTC))[reply]
It does sound like the Yonomori Line was involved in 5&6 somehow. I will put the reference back in tomorrow, if someone else doesn't.( Martin | talk • contribs 05:29, 8 May 2011 (UTC))[reply]
The commons file above is incorrect. But first of all, please note that the source is a personal site. The reason you couldn't find the Yonamori line is that the line shares pylons with the Okuma 3 and 4 line from Shin-Fukoshima substation since March 1974. The Okuma 3 and 4 line has 25 pylons. Here are the images. But I couldn't find where the Yonamori line branches off from the Okuma 3 and 4 line. It is impossible to find the detailed grid on the web because of the security reason. The Okuma 1 and 2 line is here. The operation started in September 1973 with 27 pylons. And this is the Futaba line. Operated since September 1977 with 33 pylons. The line to Daini is "Tomioka", not "Fukuoka". Here's a machine translated page of another pylon mania's blog. The original ja page is here Do you know this? The machine translated article is here. If you use machine translator use the Yahoo jp page. It's better than Google translate. I just saw your latest post. I'll try to find something more. As for the pylon 27, it was confirmed at the House of Representatives of Japan on April 27. You can watch it at here. Click 27 from the 4月 calender on the left, choose 経済産業委員会, the fifth entry, and click "吉井英勝（日本共産党）16時40分 21分". The Yonamori is the line goes to 5&6. As far as I checked, the Futaba seems to be a power-out-put line to Shin-F/Tokyo from 5&6 and the Yonamori a power-in-put line from Shin-F. Oda Mari (talk) 09:20, 8 May 2011 (UTC)[reply]
I corrected the Commons file in line with your comments about a) name of Tomioka Line (verified against TEPCO 2003 Annnual Report p24) and b) shared pylons on Okuma line (I can see them in the difference in shape of the 2 strings of Okuma line towers. The #2 towers shadows are taller, and the wires start well above the skirt.) The photos of the pylons were helpful.
It's funny that they call the line the Yonomori line, since it does not go near Yonomori. 1974 was just after Unit 6 construction started, which continued till 79. Do you know the history of this line??
The Yonomori line splits from Okuma 3-4 as it enters the plant site.
I see that the "do you know this" reference is an important explanation, but I cannot translate the Japanese. ??
Pylon 27 - I see. But what about the Tohoku line that comes in by the baseball field?
Regarding power-out vs power-in. Power lines do not have that kind of direction. For example, the Daini plant has been running the pumps using power taken from the Tomioka Line since the first TEPCO Plant status report at midnight March 11th.( Martin | talk • contribs 15:37, 9 May 2011 (UTC))[reply]
I'd like to know the exact names of 11, 12, and 13 in the image. Could you provide them? Hopefully in ja like 双葉線. How did you find them? I could not find the Tohoku line near the baseball field. In which direction can I find it? Six o'clock or eight o'clock from the baseball field? And how near/far from the field? A half mile? A quarter mile? Please let me know. Thank you. Oda Mari (talk) 05:48, 10 May 2011 (UTC)[reply]
I found the lines by looking on Google Earth. One tower is behind home plate. Tohoku's distribution substation #11 is here: 37°21′20.52″N 140°59′24.89″E / 37.3557000°N 140.9902472°E / 37.3557000; 140.9902472. I have looked at Tohoku Power Company website for information about their power distribution infrastructure, but I have not seen any. I have posted more about the diagram on its pages on commons. This article you posted is the most informative. Do you have a link to the Japanese version? ( Martin | talk • contribs 16:16, 10 May 2011 (UTC)). Often, a corridor is cut through the trees for the transmission lines. This can be easier to spot than the towers and from higher up. ( Martin | talk • contribs 16:27, 10 May 2011 (UTC))[reply]
This is the ja link. Here are the grid the Tohoku Electric Power offers on the web but the names related to Daiich and Daini are not included. [4] [5] #12 might be the 東電原子力線. According to this blog, it's an old line used when the plant was built and the name of #11 is the Tomioka substation. But I couldn't find any reliable maps nor reliable pages explaining on the line/substation. Even though they are mentioned here and there, unless you find RS, including the Yonomori line information, the Common's map is OR as tracking down the lines on the Google map by yourself is OR, I appreciate your effort though. So sorry, but as I wrote above, I think it is impossible to find the detailed grid map/information that can be used as RS on the web. Oda Mari (talk) 05:50, 11 May 2011 (UTC)[reply]
Wow, nice finds. I agree: possible copyright problem. I posted it to talk page. If it was used during construction, then I think its reasonable to guess that the 66kV line to 5&6 could also be a construction line, since it was turned on six months into the six year construction phase of 5&6. Not completely satisfactory as an answer however, since Unit 1 was operational, and Unit 2 soon would be. Might explain the name Yonomori, since it would have served the same purpose for 5&6 as Tohoku's "Yonomori" Line did for 1&2 - construction. Conjecture. ( Martin | talk • contribs 23:00, 11 May 2011 (UTC)) The purpose of the substation is to provide electricity to the neighborhood. You can see the street poles, the distribution system running right by. You have to presume that this is the station that serves Tomioka don't you?( Martin | talk • contribs 23:22, 11 May 2011 (UTC))[reply]
I'm not quite sure what you are arguing. It is not OR to collate information. If one source (eg google map) shows clearly visible power lines it is not OR to create a new map with the visible lines marked. If tepco says there are four lines coming onto the plant and names each one going to each unit, and it is possible to see in the other source which line is going to which unit, then it is not OR to add the names to the map int the appropriate places. Every time we write an article we add information from different sources into one document - there are 400 sources listed for this article...Sandpiper (talk) 22:32, 11 May 2011 (UTC)[reply]
I agree Sandpiper. The problem is not OR. For a map to be OR, I would need to fly to Japan and look for the towers, or something like that. The problem, I think, is that the map is too accurate, and it may have a copyright issue for that reason. IMHO. If you can describe the situation in words; I don't see how it could be wrong to draw a picture. ( Martin | talk • contribs 02:37, 12 May 2011 (UTC))[reply]

So what is the conclusion reached? The japanese document posted above seems to translate under google to show a line feeding power to 5&6 called the 'night forest' line. Is this a translation of 'yonomori' or is it confirmed that this is a different name for the same line, such that the tepco document does identify the feed to 5&6 as the Yonomori? Martin, transformers do run in both directions, but it is possible the low voltages from the transformers on the futaba line might still be incompatible. I dont know what voltages the main generators produce natively which is then connected to these outgoing transformers, but it might be different to the voltages which are needed to run the plant. It might have been more efficent to provide separate much smaller transformers to power the plant at a different voltage. If the 'night forest' line is lower voltage than the futaba, this too would be a cost reduction and perhaps explain the choice to run from a different line. I do not understand the diagram about power failure. It seems to imply that grid power was still available at unit 2 throughout the emergency, because no faults are shown. This seems unlikely, so are there other faults not indicated, for example power failure at the shin hukushima substaion so that there was no power to send anywhere?

The faults diagram says something like 'started only D/G 6b'. Now, I did understand all generators started initially, but I do not recall reading a definite statement that this is true. I have read several postings here and there that plant backup generators are unreliable in emergencies! The article still carries the mysterious tepco comment that the second unit of emergency generator A of unit 6 provided power a few days into the emergency. Is this the same generator as is referred to in the diagram as generator B, or does the comment on the diagram actually mean that after the earthquake, only generator B at unit 6 started up. This then failed in the tsunami but later unit A was resurrected. This might just make sense if A, having failed to start, was saved from flooding damage because it was not running. Sandpiper (talk) 21:42, 11 May 2011 (UTC)[reply]

The Shin-Fukushima substation was powering the Fukushima Daini Plant that evening; one can't say the substation was "out".
I dont think we can honestly draw much conclusion from that.
If you post in the middle of a comment, could you make it brief, with the elaboration later?( Martin | talk • contribs 17:24, 14 May 2011 (UTC))[reply]
First, what time of night and did power go off before coming back, but second as a distribution point it might be that some lines were operable while others were not, or repairs happened one by one. The diagram in the posted ref shows a number of faults which occured with the power supply but we dont know whether this is an exhaustive list or whether although it shows the distribution station it only shows faults inside the power plant itself. Power must be distributed to consumers in the area somehow, and it must be the case that major flooding occured at the consumer end of the power lines. This must have caused knock-on distribution problems.Sandpiper (talk) 14:16, 12 May 2011 (UTC)[reply]
Are you saying then that the station was "out"? No you're not. So why the comment? The most you can say is that the station was partly out. Then you need to explain, or at least claim, that the parts that were out were all the parts that went to Daiichi and all the parts that worked were the parts that went to Daini. Be my guest. What in the diagram do you see about distribution, about consumers? ( Martin | talk • contribs 17:34, 14 May 2011 (UTC))[reply]
Are you trying to make sense of the Yonomori Line? Trying to figure out why TEPCO built it?
I have the much smaller aim of trying to get the right name!Sandpiper (talk) 14:16, 12 May 2011 (UTC)[reply]
It looks as though that line is called the Yonomori Line by TEPCO, but note that it does not serve the town of Yonomori, outside of Tomioka, which has a night forest. ( Martin | talk • contribs 22:55, 11 May 2011 (UTC))[reply]
we are going to be posting in haikus next. What IS a night forest? The night forest attacked the power plant ala Dr who? Is this the name of a place which the power line went through or a chain of shops in Japan which sponsored it? Google translates the line name in the ref as 'night forest'. Presumably TEPCO supplied the information about what it was called, though somewhere there is the original release I read where it was stated power to 5&6 was restored from the yonomori line, which would seem to be both correct and precisely how power was supposed to be provided, so entirely reasonable, assuming somehow yonomri=night forest.
few words; spring air; ponder.
like the cherry blossom festival in Washington. Note the phrase "these are especially beautiful at night when lit up" ( Martin | talk • contribs 17:42, 12 May 2011 (UTC))[reply]

The asahi article includes an incomprehensible diagram in Japanese about how the plant has been rewired. Can anyone make sense of it?Sandpiper (talk) 22:38, 11 May 2011 (UTC)[reply]

Relevance?

"Plutonium contamination has been detected in the soil at two sites in the plant." How is this relevant? Does it show anything about the danger levels involved to workers at the plant that cannot be found elsewhere in the opening summary? —Preceding unsigned comment added by 82.11.1.60 (talk) 09:46, 8 April 2011 (UTC)[reply]

Addition information can be added, but since Pu can have a half-life of thousands or millions of years (depending on the isotope), its relevance is at the very least long-term contamination beyond that of the other isotopes released (cesium, iodine) and that it wasn't one-location event.MartinezMD (talk) 18:09, 8 April 2011 (UTC)[reply]
Read the source. This is not a notable or even slightly dangerous level of Plutonium (it contributes less to radioactivity than the normal soil does and the "contaminated" soil is as radioactive per kilogram as the carbon that makes up your body right now!), but the impression this phrase (due to it's inclusion in the summary) will give the reader is exactly that! 82.11.1.60 (talk) 14:17, 7 May 2011 (UTC)[reply]
I wish people would use names. But I agree with 82.11. Million year half-lifes are not as bad 1 year half-lifes. The only good thing about a two day half life, is after a month, there is no point in thinking about doing anything. ( Martin | talk • contribs 15:58, 7 May 2011 (UTC))[reply]
I would say the point is that if there is plutonium detectable anywhere which is more than the natural (or unnatural) background then it is a further measure of fuel rod damage and escape of fuel, because it can only have come from inside the fuel rods. It indicates an escalation of the problems. Sandpiper (talk) 07:54, 11 May 2011 (UTC)[reply]
Could a disclaimer that this is only an indicator of possible reactor leakage and not even slightly dangerous in itself be included to prevent people getting the wrong impression (because they almost certainly will for similar reasons to why the Material Conditional is philosophically problematic)? 82.11.1.60 (talk) 16:08, 26 May 2011 (UTC)[reply]

fuel pool heating

The asahi link posted above [6] gives figures in what seem to be kilocalories/hr for the heat being generated in the fuel pools. I translate that as 1 Kc/h=1W, so it gives unit 1 60Kw, Unit 2 400Kw, unit 3 200 Kw, Unit 4 2Mw, Unit 5 700Kw, Unit 6 600 Kw. It also gives dimensions of the fuel pools as approximately 10m x 12m x 12m deep. Sandpiper (talk) 23:36, 11 May 2011 (UTC)[reply]

Maybe spent fuel pools should not be located in reactor buildings, or any place where access is not possible in an emergency. 172.162.230.91 (talk) 11:32, 13 May 2011 (UTC) BG ..... The fuel pool cooling requirements are low enough that backup fuel pool cooling could have been simply accomplished by convection air-cooled aluminum heat sinks partially submerged in the pools. The situation might not be a disaster but it is a total fiasco, with the tsunami flooding, the cores melting, hydrogen explosions, fuel pool damage, and radiation releases. Too bad it happened at a site with multiple reactors; the harsh lessons would have been learned if this happened to only one reactor. In fairness all Japan was blind to tsunamis, but even so the reactors cascade of self-destruction is unacceptable and even shameful. An expensive long term mess. Its no wonder the Japanese government lost confidence in nuclear power. 172.129.106.51 (talk) 13:21, 14 May 2011 (UTC) BG[reply]

Reactor I Pressure Vessel Breached

BBC news reports that TEPCO has confirmed the pressure vessel at Reactor I has been breached and water is leaking from pressure vessel, likely due to melted fuel rods burning a hole though the bottom of the pressure vessel, the melted rods now form a mass of Corium.[7] The pressure vessel of Reactor I is holding only half as much water as previously thought (normally 330,000 liters), a faulty water level gauge has been replaced. It is believed Reactor I leaked 11 million liters of water though the breach. Good write up in the Wall Street Journal.[8] The article needs to be updated to reflect the current situation. --Diamonddavej (talk) 16:06, 12 May 2011 (UTC)[reply]

Reuters reporting as well [9]
RandySpears (talk) 22:19, 12 May 2011 (UTC)[reply]
I am highly skeptical of the conclusions of meltdown in #1. Note carefully what the articles claim as truth and claim as conjecture. They claim they repaired a broken gage: certainly true. They claim the new gage indicates total core uncovery right now: no doubt. Does that mean the water level actually is low? We know only that two gages disagree. (echoes of an old Jane Fonda movie.) They CONJECTURE that since the reactor has been in continuous core uncovery for months apparently, therefore the core MUST HAVE melted down into corium, and hot corium SURELY WOULD HAVE burned holes in the bottom of the reactor, which MUST SURELY explain the low temperature and pressure in the reactor. But that does not jibe with several other datapoints, including the RPV being pressurized, the relative cleanliness of the water coming out (as contrasted with units 2 and 3), and the fact that they're able to send humans into 1 and not 2 and 3. It doesn't add up. Just sayin'. 209.131.62.115 (talk) 04:43, 14 May 2011 (UTC)[reply]
I'm personally inclined to believe the IAEA's report for unit 1, (at http://www.slideshare.net/iaea/table-1-unit-1-reactor-fukushima-daiichi-nuclear-power-plant-18-may-2011) indicting that "The results of provisional analysis show that fuel pellets melted and fell to the bottom of the reactor pressure vessel." I'm thinking the IAEA is better at adding stuff up than the poster above. Just sayin'. 173.206.139.42 (talk) 16:04, 22 May 2011 (UTC)[reply]

Meltdown confirmed

There was a quote from the bloomberg article:

The government and Tepco are described as "consistently appeared to be underestimating the severity of the situation.”

The way it is now it is just bad English. The problem is I'm not really sure how to integrate it. The quote is from Paul Padley, a particle physicist at Rice University in Houston. But just attributing it to him sounds just strange (who is Paul Padley and why are we quoting him). Perhaps change the previous sentence to acknowledge bloomberg explicitly and then attribute it to the article? ("the article also quotes a particle physicist who says...") as bloomberg's a known source? Perhaps someone better than me can turn this paragraph into one coherent whole. —Preceding unsigned comment added by 188.174.94.82 (talk) 21:43, 14 May 2011 (UTC)[reply]


Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: page moved. Vegaswikian (talk) 06:02, 22 May 2011 (UTC)[reply]


Fukushima I nuclear accidents → Fukushima Daiichi nuclear accidents — Many news sources have used this name ("Fukushima Daiichi" gets 5x as many hits on Google News as "Fukushima I" (both with quotes)), and the Wikipedia article on the reactor itself is titled Fukushima Daiichi Nuclear Power Plant. 75.40.204.106 (talk) 02:06, 15 May 2011 (UTC)[reply]

Survey

Feel free to state your position on the renaming proposal by beginning a new line in this section with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.
  • Support with some reservations It should definitely be renamed from "Fukushima I". However, should it be "Daiichi" or "Dai-ichi"? TEPCO's English press releases use "Daiichi", while NISA's and NSC's use the hyphenated spelling. -- Kolbasz (talk) 21:50, 15 May 2011 (UTC)[reply]

Discussion

I notice that the previous discussion about changing the name to "Fukushima I nuclear disaster" was archived before it was closed. I believe that the event is clearly being called a disaster by the media now that there is clear evidence of partial or complete meltdowns at several of the reactors. As an administrator, I'm willing to make the call and say that the article should be either "Fukushima I nuclear disaster", "Fukushima Daiichi nuclear disaster" or "Fukushima nuclear disaster" (which seems to be the name that the media is settling on). I'm willing to reopen the discussion on "disaster" if there some good arguments are made and support for keeping "accident". If you read some of the articles that show up in google when you search on "Fukushima nuclear accident" it seems clear that the initial "accident" caused by the tsunami resulted in the "disaster". This seems to me to be the way to talk about what happened. The initial incident was the accident which caused the disaster: destruction of the plant; melt-downs; power shortages; environmental contamination; huge radioactive cleanup problems; etc. -- ☑ SamuelWantman 02:58, 17 May 2011 (UTC)[reply]
"Fukushima Daiichi" is better, since it removes the impact of Daini's evacuation perimeter, which some people would call part of any "Fukushima nuclear disaster". 65.95.13.213 (talk) 04:23, 19 May 2011 (UTC)[reply]
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Death inside the plant

from: http://www.chinapost.com.tw/asia/japan/2011/05/15/302380/Worker-at.htm The operator of Japan's tsunami-wrecked nuclear power plant said a contract worker in his 60s died Saturday after collapsing at the facility's waste disposal building, adding that his body showed no signs of dangerous levels of radioactivity. -- while not directly relevant to the radioactive event it is still directly tied to the radioactive event. Perhaps the "Reported death(s)" total should be changed from 0 to 1. I'd do it but I am by no means brushed up on style guide nor have the time. 08:12, 15 May 2011 (UTC) by unregistered noob —Preceding unsigned comment added by 75.66.68.56 (talk)

I disagree. It was a heart attack. -- Kolbasz (talk) 01:02, 16 May 2011 (UTC)[reply]

How on earth can that death be attributed to the nuclear disaster, even the link says explicitly that it is unrelated!

New report from TEPCO

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110515e10.pdf

Confirmation than reactor 1 melted down. 2 and 3 may have also. Provides some detailed information.

It should definitely be incorporated, but the use of the word "meltdown" (and variants) should be avoided to the greatest extent possible, as it's not actually a defined term - we've had confirmation of fuel melting for ages (the previous estimate put the fuel damage at 55%). What's new here is the severity of the damage (core completely destroyed, and possible damage to the RPV) and the rapidity of the event (fuel melting started just 5 hours after the quake, and was complete after only 11 more hours). Kolbasz (talk) 16:06, 17 May 2011 (UTC)[reply]

Also, the UK Chief Nuclear Inspector has published an interim 'lessons learnt' report, with an analysis of the Fukushima accidents. Not hugely in-depth, but using very reliable sources of info. Probably a good source.[10] Rwendland (talk) 20:46, 18 May 2011 (UTC)[reply]

"Continuing radiation"

The "Continuing radiation" subheading under "Reactor unit 2" is misnamed, as it's not in fact about emissions of radiation from the unit. It begins by describing the reconnection of power to the unit, and then the rest of it mostly deals with releases of radioactive water. Aside from the entirely irrelevant (for the section) portion about the power, it should probably be merged with the "Pressure vessel damage" section (under the latter's heading). -- Kolbasz (talk) 00:06, 21 May 2011 (UTC)[reply]

I did a quick cleanup of the entire "Reactor unit 2" section. Power reconnection was moved up to the section lead, the "Nuclear core damaged" subsection was split into "Pressure vessel damage" and "Reactor core damage", a "Spent fuel pool" heading was added (to match the other reactor units' sections), relevant parts from the "Continuing radiation" subsection were moved to their proper places, and the remaining "Continuing radiation" section was renamed "Containment damage". -- Kolbasz (talk) 13:08, 27 May 2011 (UTC)[reply]

File:Fukushima explosion.jpg

File:Fukushima explosion.jpg has been nominated for deletion. 65.95.13.213 (talk) 04:52, 22 May 2011 (UTC)[reply]

Why?173.206.139.42 (talk) 16:15, 22 May 2011 (UTC)[reply]
You woudl find out if you went to the discussion indicated on the file page, and read the discussion. 65.95.13.213 (talk) 06:29, 24 May 2011 (UTC)[reply]

Prompt criticality

American nuclear engineer Arnold Gundersen, noting the much greater power and vertical debris ejection compared to the unit 1 hydrogen blast, has theorized that the unit 3 explosion involved a prompt criticality in the spent fuel pool material, triggered by the mechanical disruption of an initial, smaller hydrogen gas explosion in the building.[1]

Do we really need this bit of pseudoscientific speculation in the article? Especially since if you take the time to watch the video, you'll find out that the argument he uses to support his fringe hypothesis is that a hydrogen-oxygen mix cannot detonate - it can only deflagrate. Say what? -- Kolbasz (talk) 23:41, 22 May 2011 (UTC)[reply]

To be fair to Gundersen he only says it is a plausible hypothesis that needs to be tested by comparing Xenon isotope ratios in the cloud emitted - which he says has not been disclosed although almost certainly measured. But I would agree with you that this is not WP:RS enough for inclusion. Rwendland (talk) 13:44, 23 May 2011 (UTC)[reply]

The recent move to Fukushima Daiichi nuclear disaster

It seems that the recent move to Fukushima Daiichi nuclear disaster has been done without established consensus. The discussion was about move to Fukushima Daiichi nuclear accidents. The author of the move cited an archived discussion as the main reason. I'd like to point out that neither past discussion had established the consensus, nor it can be used as a reason for move since it's several weeks old. Please move the page back to Fukushima Daiichi nuclear accidents and reopen the poll. 1exec1 (talk) 15:27, 23 May 2011 (UTC)[reply]

I concur with this. Kolbasz (talk) 21:56, 23 May 2011 (UTC)[reply]
Yes the discussion was several weeks old, but the points raised in the discussion were more valid now than they were then. Archiving and neglect are not reasons to ignore a previous discussion. Rather than restart the discussion, I read the arguments and came to a conclusion based on the arguments made pro and con. Most of the arguments for keeping it as "accident" seemed much less valid now. The press is calling the entirety of the story a disaster, and the specific problems at the plant multiple accidents. That seems reasonable. It is one of only two 7s ever, and the other is also called a "disaster". I posted my intent to close the previous archived discussion by moving the article to "disaster" and nobody commented. In consensus decision making silence equals agreement. I'll move the article back if there are good reasons to, but I haven't seen them yet. -- ☑ SamuelWantman 01:23, 24 May 2011 (UTC)[reply]
Your comment there was just that, a comment. You didn't say anything about what the results of not responding might be. I don't know what your intentions were, but I smell deception there. You could just as well restart the poll and move the page again if the editors decide that the move is needed. Everything would be clear and everyone would be happy. Yet this simple solution doesn't look good to you for some reason.
Regarding the points raised in the discussion, I must emphasize that it is not you who decides whether these points are more valid or not. It is the wikipedia editors. So please revert the move since it's a violation of the basic rules of WP:CONSENSUS and you as an administrator must know that.1exec1 (talk) 14:25, 24 May 2011 (UTC)[reply]
I've been an admin for years, and helped write WP:CONSENSUS (though I admit that I haven't read it recently). Yes, admins DO decide whether points are valid or not, and I discounted many of the arguments that said "it is too soon", because they often stated that it was too soon to judge what had really happened. But now it is confirmed that 3 reactors melted down. I will continue to act as an admin as long as I can make bold decisions after interpreting the arguments made in a discussion. I never count "votes", I just weigh well stated arguments. I've done this for some very contentious issues and think I have a good reputation. As I've stated, I'm willing to revert my decision if someone, after reading the previous discussion can make a good case for "accident" over "disaster". I find the argument that the virtual destruction of multiple reactors, billions in damages, a massive cleanup, and an entire region rendered uninhabitable overwhelmingly convincing as being labeled a "disaster" instead of an "accident". Make a convincing case for the opposite, and I'll consider reverting my decision. -- ☑ SamuelWantman 06:16, 25 May 2011 (UTC)[reply]
Ok, I agree and withdraw my previous statements. Here are my arguments:
1) No deaths, minimal health effects
Plain and simple. No radiation-related deaths has occurred and only 21 worker received radiation mare than 100mSv (See here. This reference is old, but since the radiation levels have only been falling since the time the it was written, I assume nothing has changed. If you anyone has more up to date reference please share). This is the lowest radiation dose where health effects have been measured. In this case, 1% increased risk of cancer, i.e. the probability that you develop cancer in your lifetime 44%, now it'd be 45%. No workers received more than 250mSv. The public received minimal radiation doses, because of precautionary evacuations.
2) Capital losses are not so big
The main reason of the big losses is not the accidents at the reactors, but the earthquake and the resulting tsunami. Even if there had been no accidents, the losses would have counted in billions, since so much equipment was destroyed by the tsunami. Also, there are big losses because of the downtime of the reactors (not only at Daichii, but at Dainii also), since the maintenance of the reactors is very expensive regardless the reactor is producing power or not. Another important fact is that the reactors probably wouldn't have been salvaged in any case, since the plan was to decommission them several years anyway. The only thing that inflates the costs and is direct result of the accidents is compensations to the residents of the affected region.
3) Evacuation is precautionary and not permanent
The radiation in most of the affected region is not that high (See here). As you can see, in most of the region radiation levels are lower than 2uSv/h. If this radiation was constant, than the annual radiation dose would be 17uSv or about three times an American person would get in a year (See Sievert#Yearly_dose_examples). However, the radiation levels are not constant but decreasing in exponential manner and in a year the radiation levels would be acceptable. Very important thing is that rain washes away the radioactive materials since both caesium and iodine are soluble in water. After the rainy season there would be hardly any radiation left. And the rainy season is in June in Japan. So expect the evacuation to be lifted in several months. The reasons why the Japanese officials say that it would be permanent are probably political. The reason why the evacuation area is guarded so strongly is not because the radiation is high, but because of robbers, since there are still a lot of people belongings left and it's easier to battle thieves by magnifying their radiation fears than by guarding each house.
I hope these arguments are convincing. I you have any doubts about validity of any of these statements, point me out and I'll provide references. If I didn't explain something clearly, ask and I'll explain unclear parts in detail.1exec1 (talk) 11:53, 25 May 2011 (UTC)[reply]
Judging this as disaster was correct due to the meltdowns. --Kslotte (talk) 08:33, 25 May 2011 (UTC)[reply]
Can you point me out, what exact effects, apart from a lot of unsubstantiated fear, the meltdowns have or will put inside the mix? The damaged fuel was already reported and that's meltdown.1exec1 (talk) 12:18, 25 May 2011 (UTC)[reply]
1exec1, Perhaps you are looking at this with the expectation that we decide whether this is a disaster or and accident by making a determination on the extent of the damages. That would be original research. What we have to do is look at what has published, and decide what the best, most encyclopedic name is based on the naming guidelines. That was how I came to the decision to move the article. The bulk of the reliable sources that I looked at called the entirety of the situation at the plant a "disaster", and the individual events that caused the disaster were called "accidents". If we are considering "accidents" and "disasters" at nuclear plants, and accepting that both terms are reasonable, we have to decide the line between an accident and a disaster. Looking at the citations, it seems reasonable to me to say that a disaster implies that things were destroyed, and an accident is a problem that is probably fixable. In this case there were three meltdowns that basically destroyed the three reactors. That, with the contamination, large financial looses, a huge cleanup and displaced population have clearly been called a disaster in reliable cites for quite some time. The "minimal health effects" that you mention seems premature. The cost of evacuating tens of thousands of people and decontaminating the plant and surrounding area are huge. The evacuation is because radioactivity readings were high. It is unclear how long it will last, but the damage to the displaced population is already huge. Herds of animals had to be abandoned. Farmers lost their entire crop, etc... I find it hard to think of labeling all of this as an "accident", and I don't see evidence that it has been labeled that way in the press. -- ☑ SamuelWantman 23:04, 25 May 2011 (UTC)[reply]
I think we won't come to an agreement so I'll propose a move in a formal way.1exec1 (talk) 17:24, 28 May 2011 (UTC)[reply]
Personally, I strongly prefer "disaster" over "accidents" (a prolonged dislocation of a hundred thousand people is a disaster), but if people want to have another conversation, then feel free. Dragons flight (talk) 01:38, 24 May 2011 (UT
I agree that there are reasons for calling these events disasters. However there are reasons for not doing so too. Let's firstly have a discussion and see what comes out of it.1exec1 (talk) 14:28, 24 May 2011 (UTC)[reply]

Meltdowns

TEPCO has now confirmed meltdowns in 1, 2 and 3. -- ☑ SamuelWantman 08:50, 24 May 2011 (UTC)[reply]

And something really scary: http://enenews.com/radiation-at-reactor-no-1-skyrockets-now-over-200-sieverts-per-hour -- ☑ SamuelWantman 21:50, 24 May 2011 (UTC)[reply]
Looking like the latter is a false alarm; it appears that there was a transcription error that saw them post the drywell temperature reading (201 degrees C) as the drywell radiation reading instead. rdfox 76 (talk) 23:27, 24 May 2011 (UTC)[reply]

Move back to Fukushima Daiichi nuclear accidents

The move to Fukushima Daiichi nuclear accidents was done without consensus. Here are the arguments opposing the move:

1) No deaths, minimal health effects
Plain and simple. No radiation-related deaths has occurred and only 21 worker received radiation mare than 100mSv (See here. This reference is old, but since the radiation levels have only been falling since the time the it was written, I assume nothing has changed. If you anyone has more up to date reference please share). This is the lowest radiation dose where health effects have been measured. In this case, 1% increased risk of cancer, i.e. the probability that you develop cancer in your lifetime 44%, now it'd be 45%. No workers received more than 250mSv. The public received minimal radiation doses, because of precautionary evacuations.
2) Capital losses are not so big
The main reason of the big losses is not the accidents at the reactors, but the earthquake and the resulting tsunami. Even if there had been no accidents, the losses would have counted in billions, since so much equipment was destroyed by the tsunami. Also, there are big losses because of the downtime of the reactors (not only at Daichii, but at Dainii also), since the maintenance of the reactors is very expensive regardless the reactor is producing power or not. Another important fact is that the reactors probably wouldn't have been salvaged in any case, since the plan was to decommission them several years anyway. The only thing that inflates the costs and is direct result of the accidents is compensations to the residents of the affected region.
3) Evacuation is precautionary and not permanent
The radiation in most of the affected region is not that high (See here). As you can see, in most of the region radiation levels are lower than 2uSv/h. If this radiation was constant, than the annual radiation dose would be 17uSv or about three times an American person would get in a year (See Sievert#Yearly_dose_examples). However, the radiation levels are not constant but decreasing in exponential manner and in a year the radiation levels would be acceptable. Very important thing is that rain washes away the radioactive materials since both caesium and iodine are soluble in water. After the rainy season there would be hardly any radiation left. And the rainy season is in June in Japan. So expect the evacuation to be lifted in several months.

The name used by most sources also backs up this. Google news search returns these numbers for news posted in the past month:
[Fukushima nuclear disaster] - 6162 hits
[Fukushima nuclear accident] - 6199 hits
[Fukushima nuclear crisis] - 7103 hits

Google search:
[Fukushima nuclear disaster] - ~13.9 million hits
[Fukushima nuclear accident] - ~20.8 million hits
[Fukushima nuclear crisis] - ~8.5 million hits
1exec1 (talk) 17:35, 28 May 2011 (UTC)[reply]

Argument for "disaster":
Even if no one dies or gets sick (and not counting the workers at the site who died or were injured for reasons unrelated to radiation), it is still one of the worst nuclear events in history, a massive disruption on people's lives, and has led to massive economic losses for TEPCO specifically and Japan in general. Dragons flight (talk) 19:08, 28 May 2011 (UTC)[reply]

Survey

Feel free to state your position on the renaming proposal by beginning a new line in this section with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.
  • Keep at Disaster, per my explanation above. Dragons flight (talk) 19:13, 28 May 2011 (UTC)[reply]
  • Keep, per consistency with other high-INES events mostly. Recent Google News hits between "accident" and "disaster" are about the same, so that gauge is not very useful in this case. Titoxd(?!? - cool stuff) 05:08, 29 May 2011 (UTC)[reply]
  • Keep I was the admin who made the move, and I've explained my reasons higher on the page. I'll just add that I spent quite some time reading many of the articles that used the term "nuclear accident" using the Google news search. Many, perhaps most, used both the term "accident" and "disaster". Since the numbers were comparable for accident and disaster, I concluded that the searches were finding the same articles and that press was calling the accident a disaster. So should we. -- ☑ SamuelWantman 01:44, 30 May 2011 (UTC)[reply]
  • Move to Crisis The argument I'm hearing is that making an independent judgment about the severity of the... event would constitute original research, forcing us to rely on google hit numbers. 'Crisis' seems to be leading the pack out of those options, so why are we talking about disaster vs. accident? Since there are such strong feelings about nuclear power, it is more important than ever to maintain a neutral point of view. The term 'crisis' avoids the loaded terminology we have been seeing so far (iaea trying to minimize public reaction, greenpeace trying to maximize it), and also implies that the history of the event has not yet been officially written. Which is the case I think. This would also help to distinguish between the tsunami and the ongoing events. IDK112 (talk) 08:24, 30 May 2011 (UTC)[reply]
  • Keep, per consistency with other high-INES events, and because large exclusion zones were enacted. Also, had this happened in the U.S., almost certainly the Stafford Disaster Relief and Emergency Assistance Act would have been invoked justifying the use of "disaster". Rwendland (talk) 11:24, 30 May 2011 (UTC)[reply]
  • Keep, per WP:Reliable sources. --RaptorHunter (talk) 22:05, 30 May 2011 (UTC)[reply]

"Fukushima Nuclear Disaster" has 146 recent articles. Fukushima nuclear accident has 72 recent articles.

  • Move to crisis The term crisis is more applicable to something which is still ongoing. The dominance of this term in google results reflects this. When it's all done I expect disaster will be more appropriate than accident, especially given INES scale. So I'd express a preference for "disaster" over "accident", but I think "crisis" is better still. Leopd (talk) 04:30, 1 June 2011 (UTC)[reply]
  • Move to crisis. The sources appear to use the term "crisis" more than "disaster". Cla68 (talk) 00:16, 2 June 2011 (UTC)[reply]
  • Support Move to accident or crisis. The arguments for "disaster" appear to rest on the shock value of nuclear meltdown regardless of whether or not that has caused substantial harm, and the financial loss to TEPCO (mostly asset write-off, so far). The evacuation on its own is of course massively disruptive but would not ordinarily rise to the description of disaster. The mass media article count is not reliable as an arbiter given their intrinsic bias towards more dramatic descriptions. I do NOT consider an analysis of the facts on the ground in deciding this matter as constituting "original research" - this is a name selection, not content addition. Joffan (talk) 12:37, 2 June 2011 (UTC)[reply]
  • Move to crisis. What Joffan said, plus: Google News: "Fukushima nuclear crisis": 195 hits. "Fukushima nuclear disaster": 165 hits. "Fukushima nuclear accident": 68 hits. Kolbasz (talk) 17:00, 2 June 2011 (UTC)[reply]
  • Nearly anything would be better than the current title. "Disaster" is a loaded, inherently POV term that has no business appearing anywhere in a neutral encyclopedia except as part of a direct quotation. 74.74.150.139 (talk) 20:24, 2 June 2011 (UTC)[reply]
"Disaster" is what it is officially described as by the IAEA and Japanese authorities per the INES scale, so your argument carries no weight.--Pontificalibus (talk) 09:17, 4 June 2011 (UTC)[reply]
Please back up this assertion with citations. Every reference I can find directly from the IAEA—as opposed to those filtered through news organizations trying to sell advertising—describes INES 7 as "major accident" (e.g. [13], [14]); the #1 and #5 stories on iaea.org are currently "Fukushima Nuclear Accident", not "Fukushima Nuclear Disaster". 74.74.150.139 (talk) 11:08, 4 June 2011 (UTC)[reply]
Sorry, my mistake - I was thinking of something else entirely. --Pontificalibus (talk) 19:22, 4 June 2011 (UTC)[reply]
  • Keep at Disaster. These reactors had at least another 10 years of life left in them (as Unit 1 just had a 10 year license extension approved), and the replacement cost alone would be in the order of 10 billion (not to count the decomissioning costs). I really dislike the phrase 'crisis' - as the only difference between a disaster and crisis, is that a crisis is a disaster that has a time limit (and so in 6 to 12 months time, when things are more stable, what is happening at Fukushima will no longer be a 'crisis'). 74.74.150.139 made a valid point, that "Disaster" is a loaded, inherently POV term - but the same is true for 'crisis' as well.... MWadwell (talk) 22:51, 2 June 2011 (UTC)[reply]
    • Comments about impact constitute original research. A crisis does indeed have a time limit, after which the article would be changed again, using information that will be available later. A crisis does not simply end, a crisis gets recategorized and cataloged by history after more information is available. I think we can all agree that the long term impact of the event is still unknown. 'Crisis' IS a neutral pov word, since it is supported by the only mutually agreed upon official source in this discussion: google hit numbers. IDK112 (talk) 16:47, 3 June 2011 (UTC)[reply]
The initial incident was an "accident", which led to the meltdown of 3 reactors, release of radioactive material, and an evacuation which is a "disaster". The "crisis" is still continuing. All three of these terms are accurate. The effects of Chernobyl are still continuing, yet that is not called a "crisis", but rather a "disaster". If it wasn't clear that it was already a disaster, I'd be all in favor of a rename to "crisis", but I don't think there is any chance that what we learn in the future will make this any less of a disaster. The trend has been quite the opposite -- initial reports understated the damage and contamination. The article needs an overhaul to start explaining what happened in retrospect using all the information we now know to be reliable, rather than recounting the day-by-day unfolding of misinformation. Three reactors had meltdowns and core damage in the first few days. That information was only known recently, but now that we know it, we should start with a summary of what we know know has happened, and then latter in the article recount how the information unfolded. I would not mind is all the details of how events unfolded was moved to a separate article, with just a brief summary here. -- ☑ SamuelWantman 07:22, 4 June 2011 (UTC)[reply]
To quote the earlier move discussion, which ended in your unilateral decision as administrator to move the article: "...Perhaps you are looking at this with the expectation that we decide whether this is a disaster or and accident by making a determination on the extent of the damages. That would be original research. What we have to do is look at what has published, and decide what the best, most encyclopedic name is based on the naming guidelines. -- ☑ SamuelWantman 23:04, 25 May 2011 (UTC)" Being an administrator does not give you the right to engage in original research. Please show evidence to support your assertions about media use of the relevant words. Perhaps a different administrator should be called in to adjudicate, given the strong feelings on both sides. For reasons described in previous polls, I do not agree with you that new information will only reveal things to be more of a disaster.IDK112 (talk) 20:41, 4 June 2011 (UTC)[reply]
Really? That seems to be the trend. Every day there seems to be updates to the extent of the core damage, leaks, the levels of radiation in the plant (note that USA today calls it a disaster), the amount of contamination, and admissions that things were worse than originally reported. These links were just the first few I found... -- ☑ SamuelWantman 08:16, 5 June 2011 (UTC)[reply]
I disagree. It is absurd to say that things can only get worse. Some of those articles you linked actually describe containment efforts which are making things better. This argument constitutes original research, however, and is not relevant to the naming discussion. IDK112 (talk) 22:14, 5 June 2011 (UTC)[reply]
I don't think you understood what I wrote. I didn't say that things can only get worse, I said that the trend of what we are finding out about what already happened is showing the events to be worse than originally reported. We are not finding that the accident was less severe than first thought, so I think it is very unlikely that a future report will come out and say that the three reactors did not melt down, and there were no leaks. Because we now know that three reactors melted down, and there are some serious leaks, and that information is reliable, and that the seriousness of the reports is very unlikely to have been over reported, it is already a disaster. -- ☑ SamuelWantman 06:56, 6 June 2011 (UTC)[reply]
I think it is entirely possible that future reports will contradict information now being reported, possibly by saying that things were not as bad as they thought. Furthermore, the seriousness of the problem there is not determined by the internal state of the reactors, but by the external conditions, the length of the evacuation, the contamination etc... The Three Mile Island reactor was a mess inside, but that was hardly a disaster. It is entirely possible that Japan could announce tomorrow that the evacuation radius was larger then necessary and start letting people back in. You say that the media reports are unlikely to be exaggerated. I disagree. Alarmist reporting has terrified people in freaking California, which is clearly unfounded.
And again, this is all original research. The only agreed upon official source for this discussion is the google name hits, which indicate crisis is the most common name. Your personal opinion as to whether this is a disaster is irrelevant. So is mine.IDK112 (talk) 17:18, 6 June 2011 (UTC)[reply]
The prohibition on original research does not mean, and was never intended to mean, that we should be mindless automatons parroting the news agencies. We are expected to use our own judgment and consensus to determine what is important and reliable, etc. That's part of the reason we have discussions like this. The idea that the only thing we should consider are google hits is frankly ridiculous. If you don't believe the facts on the ground and the current reporting justify calling it a "disaster", then that is fine. But the idea that we should all ignore the facts on the ground is silly. Dragons flight (talk) 19:25, 6 June 2011 (UTC)[reply]
That's not really what I was saying, an earlier move discussion was preempted by Sam|uelWantman on the grounds that debate about impact was meaningless and only media common name use mattered. I was arguing to that. IDK112 (talk) 23:41, 6 June 2011 (UTC)[reply]
(outdenting) While I don't believe we should just go by the Google numbers -- (I'd rather interpret how these terms are being used by reliable sources) -- here's the latest Google results (past month):
-- ☑ SamuelWantman 19:15, 6 June 2011 (UTC)[reply]

Units of Radiation

I had previously rewritten the article to exclusively report radiation dose in milli-Sieverts (mSv) for consistency and ease of understanding by non-experts. For the majority of radiation doses in the article, this generates numbers from 0.001 to 1000 which seems a reasonable range. But there are a couple places where doses are reported in the nano-Sievert range, which for consistency requires writing numbers as 69 nSv as 0.000069 mSv. The former notation (69 nSv) is clearly preferable for anybody who understands the metric system and scientific notation. But because this is an article about news / current events, and not a scientific article, I felt that 0.000069 mSv would be more instructive for this article's audience. The article is currently written mostly in mSv, but with nSv in a couple places where lots of zeros would be needed to express the number in terms of mSv. But IMHO those zeros are very useful for this non-scientific article to explain the huge variation in scale between the numbers contained herein. I believe all this is consistent with WP:MOSNUM#Numbers and WP:UNIT given that this is a non-scientific article. Basically, I'm saying that because this article is intended for non-experts, we should stick to a single unit of radiation dose, even when it's numerically inconvenient. What do other people think? Leopd (talk) 05:59, 1 June 2011 (UTC)[reply]


I say no. Units should use the same prefix as their references, unless clearly inconvenient (e.g. your 0.000069 mSv should never be written that way, even if that's what the reference states). Conversions make it harder to check references, and add to the possibility of introducing errors not just in value but also stated accuracy.
To the completely uninitiated reader, whatever value you state is Just A Number, so to them it does not matter. To anyone who looks up Sievert, there's a helpful Sievert#SI multiples and conversions section, as well as a few wikilinked prefixes in the article. To anyone who uses the metric system - which will be a major portion of the article's readership - prefixes are likewise no problem. To the more informed reader and editor, there are also matters of customary notation: ambient dose rates, for example, are almost always stated in µSv/h unless you go past 1 mSv/h, while doses are usually expressed in mSv unless you go (well) past the 1 Sv mark. This, BTW, means that even if the entire article uses mSv/h, the hypothetical prefix-confused reader trying to look up e.g. the background radiation where he or she lives will still get confused...
And going by WP:MOSNUM:

SI units are written according to the SI standard unless otherwise specified in this Manual of Style (dates and numbers).

The Sievert is an SI unit, and inherent in SI is using a proper prefix. Kolbasz (talk) 13:43, 1 June 2011 (UTC)[reply]

Bogus information in table

The table of statistics for each reactor unit is claiming that the reactor vessel pressure is -0.03 MPa (absolute), which is an impossibility. You cannot have negative absolute pressure. If you want to claim that this refers to a pressure which is less than atmospheric pressure, then it is not an "absolute" pressure measurement.Eregli bob (talk) 15:34, 1 June 2011 (UTC)[reply]

It's called instrumentation error. Basically every instrument has an accuracy of X +/- Y - where Y is dependant on how large X is. A BWR runs at ~70 bar (or 7 MPa - see http://www.ati.ac.at/fileadmin/files/research_areas/ssnm/nmkt/06_BWR.pdf), and so even a 1% instrument error is going to result in a accuracy of +/- 70 kPa. MWadwell (talk) 01:43, 2 June 2011 (UTC)[reply]

NHK references

Be wary of using NHK World references - the URLs are recycled, so the links don't stay alive for very long. I went through all the NHK references in the article and tagged the broken ones with {{Dead link}} (and removed redundant NHK references altogether). The remaining ones should either be replaced with other references, or mirrored somewhere before they disappear. Kolbasz (talk) 14:31, 2 June 2011 (UTC)[reply]

About chest x ray

Here http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115329.htm

mSv from a chest x-ray are 0,02.

But from here http://nrc.gov/images/about-nrc/radiation/factoid2-lrg.gif mSv are 0,1 (10 mRem).

Claiudio (talk) 20:41, 5 June 2011 (UTC)[reply]

And there are estimates all in between - but 0.02 and 0.1 mSv are pretty much the lower and upper bounds, respectively. The estimates differ depending on the assumptions used: average dose per image, single image (e.g. just a posterior-anterior) VS whole procedure (e.g. posterior-anterior + lateral), etc.
(It should be noted that in real life, the actual received dose will also vary, depending on equipment (modern direct digital imaging usually gives lower doses than film, for example), procedures, etc.) Kolbasz (talk) 23:04, 5 June 2011 (UTC)[reply]

Any discussions that compare nuclear contamination to chest x-rays need a caveat that explains that radioactive particles consumed in food or inhaled are far more dangerous than a similar dose in an x-ray. The comparison to x-rays is done to make the contamination seem innocuous, and less of a concern, which is misleading. -- ☑ SamuelWantman 23:44, 7 June 2011 (UTC)[reply]

"Any discussions that compare nuclear contamination to chest x-rays need a caveat that explains that radioactive particles consumed in food or inhaled are far more dangerous than a similar dose in an x-ray."

No. That is flat-out wrong. While it's true that internal contamination is in general something to be more worried about than external radiation (due to the former's potential to deliver a high dose, from longer exposure and better α/β penetration), it's still just the dose that matters. 1 mSv in some tissue from an internal source is just the same as 1 mSv from an external source. A good radiation protection data sheet will state exposure values for ingestion and inhalation - taking into account deposition areas in the body, biological half-life, radioactive half-life, etc. - as a dose/activity value (e.g. ingestion of 131
I
: 2.2E-08 Sv·Bq-1[2]). Kolbasz (talk) 15:02, 8 June 2011 (UTC)[reply]
It was my understanding (and I might be wrong about this) that a 1mSv dose from a single radioactive particle within the body was far more dangerous than a 1mSv dose from an evenly distributed external source like an X-ray because the cells around the particle are bearing the brunt of the radiation and thus are more likely to be damaged. The Wikipedia article on Alpha particles says:
When alpha particle emitting isotopes are ingested, they are far more dangerous than their half-life or decay rate would suggest, due to the high relative biological effectiveness of alpha radiation to cause biological damage, after alpha-emitting radioisotopes enter living cells. Ingested alpha emitter radioisotopes (such as transuranics or actinides) are an average of about 20 times more dangerous, and in some experiments up to 1000 times more dangerous, than an equivalent activity of beta emitting or gamma emitting radioisotopes.
Is this not so? If not, why do you concur that "internal contamination is in general something to be more worried about than external radiation (due to the former's potential to deliver a high dose, from longer exposure and better α/β penetration)". Is there a way to say that contamination is more dangerous than background radiation because it has the potential to be ingested and bioaccumulated, leading to a more concentrated dose, that you would find agreeable? What bothers me is that it seems misleading to compare nuclear contamination to background radiation or chest x-rays, when it is, as you say, "something to be more worried about". What do you think is a fair and balanced way to say that in the article? There also doesn't appear to be a consensus in the scientific community about how much more dangerous these particles are inside the body. That being the case, we should state that there is a lack of consensus about the extent of the additional harm and give a sense of the range of opinions. -- ☑ SamuelWantman 08:33, 9 June 2011 (UTC)[reply]
The sievert is a unit of equivalent dose: unlike the gray (Gy, or J/kg) which just measures the absorbed energy, it's weighted for the biological effects of different types of radiation. The "20 times more dangerous" part in the quote above refers to the quality factor, or radiation weighting factor, which is set at 20 for alpha radiation. In other words, while 1 mGy of gamma radiation is equivalent to 1 mSv, 1 mGy of alpha radiation is equivalent to a whopping 20 mSv. So while alpha radiation is much more harmful per unit of absorbed energy, it's still just the equivalent dose that matters. It's specifically what the sievert is for, to get a dose measurement in terms of how harmful it actually is. As for the "1000 times more dangerous" part, I don't know what they're going on about - but the followup, "than an equivalent activity of ...", leads me to believe that they're not quite sure themselves, as you can't really compare different radionuclides that way. Even if you look at just gamma radiation, you'll get that kind of difference between different nuclides. For example, the specific gamma ray constants of 238
U
 and 60
Co
 at 30 cm (using the same reference as the 131
I
 dose above) is 1.25E-5 and 1.26E-2 mSv·h-1·MBq-1, respectively - or almost exactly a factor 1000 higher dose rate for the same activity.
The thing about the single particle being more harmful sounds like the "hot particle hypothesis", which has not been borne out by experiments (or studies of human accidental exposures), and is today considered fringe science in the field of radiation protection. (Sadly, fringe science has a tendency to crop up in Wikipedia articles, and it's hard to tell fringe from accepted science on the internet)
Internal contamination is something you worry more about on than external radiation, as even a fairly small ingested/inhaled activity can lead to a relatively high dose (and for alpha radiation, it is the only way to receive a dose (disregarding the corneas) - externally, it is harmless, since the high energy, low penetration alpha particles will not penetrate the outmost layer of dead skin cells). And most of the radiation dose to the public from a release of radioactivity like this one is indeed more likely to be from ingested/inhaled radioactivity rather than ambient radiation. But equivalent doses are still comparable! For instance, internal radiation is used in medical imaging: PET scans, scintigraphy and radioactive iodine uptake tests all rely on the deliberate ingestion or injection of a radioactive substance, but the dose can be calculated to not pose an undue risk to the patient (the dose from a PET scan (internal radiation) and a CT scan (external radiation) are roughly equivalent).
It should also be noted that a fair amount of your yearly background dose comes from internal radiation - 40
K
, and to a lesser extent, 14
C
, in the body, and other ingested/inhaled emitters from naturally occurring radioisotopes in the environment (for example, radon). So to say that you can't compare background radiation and radioactive contamination is also off, since the latter is in fact a large and inescapable part of the former.
Phew. This became a long post, but I hope it was educational. Kolbasz (talk) 12:22, 9 June 2011 (UTC)[reply]
Oh, and on the text you've added to the lead:

Radiation from environmental contamination can become concentrated is some locations due to wind and rain. Radioactive particles are a hazard when they are consumed or inhaled. [3]

I see what you're trying to say, and it's basically correct, but there are few issues. One is a radiation/radioactivy mixup. Another is that the reference only backs up the second sentence. The last is that I'm not entirely convinced it belongs where it's at right now. Anyway, it should probably read something like this:

Radioactive particles [from fallout/in the environment] can be concentrated in some locations due to wind and rain, and pose an additional health hazard when ingested or inhaled.

This should be a good enough free reference for rainfall concentration (search for "wet deposition"): http://www.icsu-scope.org/downloadpubs/scope50/chapter06.html Kolbasz (talk) 15:31, 9 June 2011 (UTC)[reply]
Thank you very much for your excellent explanation. Let me ask you this about the radiation reports from Japan: How do they decide how much is being ingested or inhaled? Since the dangers of alpha emitters are so dramatically different, it would seem a conservative estimation of how much will be ingested or inhaled would result in a much lower equivalent dose than a generous estimate. Is there reliable scientific data for determining the levels of ingestion for this type of accident?
I am fine with your changes to my edits, and I too am not sure where the best location would be. Perhaps a new paragraph or section is needed that discusses the variation and lack of certainty around the reports of contamination. [15] -- ☑ SamuelWantman 19:39, 9 June 2011 (UTC)[reply]

Radiation leak double what was originally reported.

Breaking news: [16]

Hydrogen explosion- Question

Some reports say the hydrogen came form zirconiun-water reactions in the spent pools; some that it came from reactions within the reactor pressure vessels. If from inside the reactor vessels, the hydrogen would leak out of the damaged vessels, but then how did it get out of the containment shells in units 1 & 3, which are not suposed to have been damaged? Tvbanfield (talk) 15:49, 10 June 2011 (UTC)[reply]

Containment pressures of Units 1 to 3
By exceeding the 427 kPag = 527 kPa design pressure of the primary containments and escaping through the overloaded top flange gaskets; see Lochbaum's theory and NISA's confirmation ("functions of the gasket on the flange section and the seal on the penetrating section have weakened"). Or have a look at the diagram to the right: Pressure rises only to some 750 kPa in Unit 1 and 2, resp. 500 kPa in Unit 3, except for short moments when very much steam at once came from pressure vessels. It didn't rise more, because the gaskets won't stand more than that. Looks like the cap screws of No. 3 were not that tight ... --87.162.161.205 (talk) 00:51, 13 June 2011 (UTC) (de:PM3)[reply]
Before someone asks for automatic safety relieve valves: The containment vessels don't have any! That's U.S. reactor design: "You have the N.R.C. containment isolation guys who want containment closed, always, under every conceivable accident scenario" [17]. Well, they overlooked the gaskets. --87.162.161.205 (talk) 01:10, 13 June 2011 (UTC)[reply]

NBC

I wonder if the reason NBC news would rather talk about Oprah Winfrey, Weiner's weiner, and Bin Laden is because they are owned by GE which incidentally built the reactors at Fukishima? Leaking nuclear reactors are no longer news? Yack all you want to about this not being a forum, but that just depends on who you are and what your agenda is. 76.246.235.134 (talk) 23:04, 13 June 2011 (UTC)[reply]

  1. ^ "Gundersen postulates Unit 3 explosion may have been prompt criticality in fuel pool". Fairewinds Associates. 26 April 2011. Retrieved 27 April 2011.
  2. ^ Delacroix, D. (2002). Radionuclide and radiation protection data handbook (2 ed.). Nuclear Technology Publishing. p. 108. ISBN 1 870965 87 6. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ "Radiological Attack: The Danger". U.S. Dept. of Homeland Security. Retrieved 9 June 2011.
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