Japan Earthquake: Nuclear Plants at Fukushima Daiichi

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Discussion Overview

The discussion revolves around the technical aspects and current status of the nuclear plants at Fukushima Daiichi following the earthquake and tsunami in Japan. Participants are seeking reliable information regarding the operational conditions, safety measures, and potential risks associated with the nuclear reactors in the aftermath of the disaster.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants express skepticism about the reliability of media reports and emphasize the need for technical information from official sources like TEPCO and METI.
  • There are concerns regarding the reactor pressure levels, with reports suggesting that pressure may have exceeded safe limits, which some participants describe as a significant issue.
  • Questions are raised about the likelihood of a meltdown, with differing opinions on whether this is a realistic concern or media exaggeration.
  • One participant explains the role of coolant in a nuclear power plant, noting that it is essential for cooling the reactor and managing decay heat after shutdown.
  • There is discussion about the reactor's ability to be scrammed (shut down) and the implications of losing coolant, with some participants clarifying that decay heat continues to be produced even after shutdown.
  • Concerns are raised about the explosion of the containment building and its implications for safety, with speculation about the potential release of radioactive materials.
  • Participants discuss the wind direction at the time of the explosion and its potential impact on the dispersion of any radioactive materials released.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the likelihood of a meltdown or the implications of the current situation at Fukushima Daiichi. There are multiple competing views regarding the severity of the situation and the reliability of information being reported.

Contextual Notes

Participants note the limitations of available information, including the reliance on second-hand reports and the challenges in verifying the status of the reactors and containment structures. There are also unresolved questions regarding the operational status of safety systems and the exact nature of the explosion.

  • #13,591
Apparently the Onagawa Plant on the northern end of Honshu sustained less damage than expected during the earthquake of March 11, 2011.

The Onagawa nuclear power plant on Japan's northeastern coast - the closest plant to the epicentre of the massive earthquake and tsunami of 11 March 2011 - suffered remarkably little damage, a mission from the International Atomic Energy Agency (IAEA) has concluded.
. . . .
A major contributing factor to this is that the plant sits on an elevated embankment almost 14 metres above sea level. Although the earthquake knocked out four of the five external power lines, the remaining line provided sufficient power for the plant's three reactors to be brought to cold shutdown.
. . . .

http://www.world-nuclear-news.org/RS-Onagawa_plant_remarkably_undamaged_says_IAEA-1008124.html

http://www.washingtonpost.com/world/asia_pacific/iaea-japan-nuclear-plant-closer-than-fukushima-to-quake-epicenter-is-remarkably-undamaged/2012/08/10/7e2fc23a-e2d0-11e1-89f7-76e23a982d06_story.html

http://www.tohoku-epco.co.jp/electr/genshi/npi/onag-e.htm
 
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  • #13,592
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120811/index.html An interview video of the then plant manager Yoshida made on 10 July (that is before his cerebral hemorage) for a Nagano publishing house was aired on 11 August at a symposium in Fukushima City. For example concerning the explosion at unit 3 he says that first he thought it would not be strange if he died. Then tens of workers were missing and he thought perhaps 10 people might be dead.
 
  • #13,593
  • #13,594
LabratSR said:
Removal of PCV Lid from the Upper Part of Unit 4 Reactor Building

http://youtu.be/J06eca4GPmg

The dismantlement of Unit 4 seems to be proceeding apace. I wonder what they'll do with the old shroud. It's too big for a transfer cask.
 
  • #13,595
LabratSR said:
Removal of PCV Lid from the Upper Part of Unit 4 Reactor Building

http://youtu.be/J06eca4GPmg

Hitachi\GE certainly seem to be in the "there's no such thing as bad publicity" camp.
 
  • #13,596
zapperzero said:
The dismantlement of Unit 4 seems to be proceeding apace. I wonder what they'll do with the old shroud. It's too big for a transfer cask.

Perhaps it will be cut into sections in situ as per the original plan?

Does the steam dryer\seperator pose a logistics problem also?
 
  • #13,597
westfield said:
Perhaps it will be cut into sections in situ as per the original plan?

Does the steam dryer\seperator pose a logistics problem also?

I wonder if those parts are any worse than the general rubble collected from the site.

For example the concrete pieces from under the broken venting pipes, or the venting pipes themselves... If those could be dumped somewhere on-site safely then maybe there is some more place there for these parts.
 
  • #13,598
Rive said:
I wonder if those parts are any worse than the general rubble collected from the site.

For example the concrete pieces from under the broken venting pipes, or the venting pipes themselves... If those could be dumped somewhere on-site safely then maybe there is some more place there for these parts.

Good point. I wasn't thinking. The U4 shroud and steam dryer are now comparitively insignificant issues compared to the big picture on the site.
 
  • #13,599
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120821/1930_gakkai.html The Atomic Energy Society of Japan has launched an investigation committee composed of about 40 members who will investigate the Fukushima Daiichi accident from a specialist's point of view. They will complete their report by December 2013. The committee held its first meeting on 21 August behind closed doors, which is likely to stir controversy.
 
  • #13,600
tsutsuji said:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120821/1930_gakkai.html The Atomic Energy Society of Japan has launched an investigation committee composed of about 40 members who will investigate the Fukushima Daiichi accident from a specialist's point of view. They will complete their report by December 2013. The committee held its first meeting on 21 August behind closed doors, which is likely to stir controversy.

What kind of specialist(s) would that be? (Sorry, I don't speak Japanese and would be grateful for the additional info.) Thanks.
 
  • #13,601
mscharisma said:
What kind of specialist(s) would that be? (Sorry, I don't speak Japanese and would be grateful for the additional info.) Thanks.
The members' list is provided on http://www.aesj.or.jp/info/pressrelease/PR20120817.pdf pages 2/3 and 3/3. You can use http://translate.google.com/translate?hl=en&ie=UTF8&langpair=ja%7Cen&u=http://www.aesj.or.jp/info/pressrelease/PR20120817.pdf to find which institutions (universities, etc.) they belong to (in the right column), and which existing AESJ committees are recommending them. The last 5 people are observers.

(*) Contains a few mistakes such as (独) mistakenly rendered by Google as "(Germany)" although it actually means "(independent body)".

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120822/index.html A 57 year old contractor company employee was found unconscious at around 10:00 AM on 22 August in a rest area. He was taken to hospital in Iwaki but declared dead, presumably from myocardial infarct, at around 01:00 PM. He had been working at Fukushima Daiichi since August of last year. On 22 August he was installing tanks for water decontamination, when he felt unwell and left to the rest area. This is the 4th worker dying of presumably myocardial infarct at Fukushima Daiichi since March 2011.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120823/index.html The NISA has issued instructions concerning the so-called "alarm typers", devices which record alarm signals in nuclear power plants, reflecting the fact that one of them failed 12 minutes after the earthquake on 11 March 2011 at Fukushima Daiichi unit 1, because of paper jam, as a consequence of which some records are missing, and the status of some vital equipments cannot be checked, making the analysis of the accident more difficult. Recording devices in 66 nuclear facilities over Japan must be inspected, the NISA instructed. The NISA also required Tepco to check if the failed recorder had had troubles before the accident.
 
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  • #13,602
Thanks a bunch, tsutsuji!
 
  • #13,603
tsutsuji said:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120822/index.html A 57 year old contractor company employee was found unconscious at around 10:00 AM on 22 August in a rest area. He was taken to hospital in Iwaki but declared dead, presumably from myocardial infarct, at around 01:00 PM. He had been working at Fukushima Daiichi since August of last year. On 22 August he was installing tanks for water decontamination, when he felt unwell and left to the rest area. This is the 4th worker dying of presumably myocardial infarct at Fukushima Daiichi since March 2011.

Umm... does this mean cause of death unknown? I have ugly flashbacks when I see this "presumably" because my country went through a turbulent period a while ago - various people were dying at demonstrations or in police custody and the cause was reported as "cardio-respiratory arrest" - i.e. died of being dead.

Could be just me being paranoid as usual, of course.
 
  • #13,604
zapperzero said:
Umm... does this mean cause of death unknown? I have ugly flashbacks when I see this "presumably" because my country went through a turbulent period a while ago - various people were dying at demonstrations or in police custody and the cause was reported as "cardio-respiratory arrest" - i.e. died of being dead.

Could be just me being paranoid as usual, of course.

Well, the temperature has been hovering around the mid 30s for the last few weeks. Working in that, wearing protective gear, carrying heavy equipment, 57 years old...it's not that unlikely.
 
  • #13,605
Shinjukusam said:
Well, the temperature has been hovering around the mid 30s for the last few weeks. Working in that, wearing protective gear, carrying heavy equipment, 57 years old...it's not that unlikely.

No it is not. But, the quote seems to imply that autopsies are not performed. I find this troubling.
 
  • #13,606
zapperzero said:
Umm... does this mean cause of death unknown? I have ugly flashbacks when I see this "presumably" because my country went through a turbulent period a while ago - various people were dying at demonstrations or in police custody and the cause was reported as "cardio-respiratory arrest" - i.e. died of being dead.

Could be just me being paranoid as usual, of course.

I can't read Japanese, but EX-SKF blog reported/commented on the Mainichi Shinbun article(s) regarding the death, according to which TEPCO announced the cause as myocardial infarction. Personally, I would like to see an autopsy as to what caused the heart attack. The information TEPCO apparently provided that it was not radiation-related without further detail as to the cause of the heart attack does not satisfy me - to say the least. But that discussion probably doesn't belong in this forum. Anyway, you may find further info here:
http://ex-skf.blogspot.it/2012/08/fukushima-i-nuke-plant-57-year-old.html
 
  • #13,607
zapperzero said:
No it is not. But, the quote seems to imply that autopsies are not performed. I find this troubling.

What would you even expect to see?
 
  • #13,608
  • #13,609
zapperzero said:
No it is not. But, the quote seems to imply that autopsies are not performed. I find this troubling.

zapperzero said:
I'd expect at the very least whole body counts and blood work for all the dead - as opposed to dose tallies based on the readings of personal dosimeters which may or may not have been covered with lead sheets.

But the symptoms of radiation poisoning don't include dropping dead in the manner of minutes, so, Occam's.
 
  • #13,610
Actually the NHK does not say "presumably". Please consider my informations as short summaries or notes taken down after reading the NHK article rather than exact translations. More accurately, the NHK says:

死因は、心筋梗塞とみられるということです。

The cause of death [of the 22 August dead employee] is viewed as being a myocardial infarct, it was said.

福島第一原発では、去年3月の事故のあと、これまでに40代から60代の男性作業員4人が心筋梗塞などで亡くなっています。

At Fukushima Daiichi NPP, after the March 2011 accident, until now 4 male workers in their 40s to 60s have died of myocardial infarct etc.
 
  • #13,611
Shinjukusam said:
But the symptoms of radiation poisoning don't include dropping dead in the manner of minutes, so, Occam's.

Occam is not in the game here. IMHO it's not 'we have better, nicer explanation' time but 'the person did not get more radiation than his record' time.

Occam plays when explanations gets too complex. But here we need knowledge about something what's not there. (I hope it's not there. I even think it's not there. But I can't be sure. )
 
  • #13,612
Shinjukusam said:
But the symptoms of radiation poisoning don't include dropping dead in the manner of minutes, so, Occam's.

I have not claimed that they dropped dead from prompt doses, so you're fighting a strawman here.

Sure, exposure to radiocesium may or may not have direct, immediate effects on the cardiovascular system (iirc there was a study after Chernobyl, never repeated though).

Sure, they were old and frail and doing hard work (which is a health&safety violation in and of its own, but I digress). The issue, as I see it, is that the doses they got may or may not have contributed to their deaths - and we can't tell.
 
  • #13,613
zapperzero said:
I have not claimed that they dropped dead from prompt doses, so you're fighting a strawman here.

Sure, exposure to radiocesium may or may not have direct, immediate effects on the cardiovascular system (iirc there was a study after Chernobyl, never repeated though).

Sure, they were old and frail and doing hard work (which is a health&safety violation in and of its own, but I digress). The issue, as I see it, is that the doses they got may or may not have contributed to their deaths - and we can't tell.

Okay...now you're just being paranoid.
 
  • #13,614
Shinjukusam said:
...now you're just being paranoid.

 
  • #13,615
tsutsuji said:
Actually the NHK does not say "presumably". Please consider my informations as short summaries or notes taken down after reading the NHK article rather than exact translations. More accurately, the NHK says:

死因は、心筋梗塞とみられるということです。

The cause of death [of the 22 August dead employee] is viewed as being a myocardial infarct, it was said.

福島第一原発では、去年3月の事故のあと、これまでに40代から60代の男性作業員4人が心筋梗塞などで亡くなっています。

Thank you so very much for the clarification.
 
  • #13,616
zapperzero said:
...
Sure, exposure to radiocesium may or may not have direct, immediate effects on the cardiovascular system (iirc there was a study after Chernobyl, never repeated though). ...

As far as I'm concerned, that statement hits the nail on the head. If nothing else, Japan has - unfortunately - the opportunity and technology to do extensive studies, and it doesn't seem to be happening. Or at least not publicly, anyway (that I know of). Why on Earth wouldn't deaths be further examined and investigated?
I don't think it has anything to do with being paranoid if one becomes inquisitive or even suspicious about that. Especially in light of the exposed practice to cover dosimeters or simply not wear them as necessary, a thorough examination should be done in this type of case to, at the very least, stop the practice of "cheating" with the dosimeters.
 
  • #13,617
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120823/index.html In consequence of the dosimeter lead cover problem that was revealed last month, Tepco made an investigation on radiation exposure management and found 24 cases such as workers losing their dosimeter, or forgetting to carry it. In 19 cases workers lost their dosimeter on the work area or while changing clothes, and in 5 cases they forgot to take a dosimeter in the first place. Tepco made estimates of the radiations received by these workers, and the worst case is estimated to be 0.72 mSv for a 3 hour long work. On 10 August 2012 Tepco initiated a dosimeter checking policy, but on 16 August, one case was found where a worker had lost his dosimeter. Tepco said they want to intensify the recurrence prevention policy.
 
  • #13,618
tsutsuji said:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120823/index.html In consequence of the dosimeter lead cover problem that was revealed last month, Tepco made an investigation on radiation exposure management ... .

As long as it is Tepco (or any other NPP operator) who makes investigations and provides statements that employee health problems/deaths are not radiation-related, they are, imho, pretty much meaningless. Too much self-interest involved. In fact, the entire accident management and mitigation procedures should have been overseen by an independent, preferably international body from day 1 or at least asap thereafter.
 
  • #13,619
http://www.meti.go.jp/committee/notice/2012a/20120823003.html The 9th mid and long term meeting is scheduled on Monday from 10:00 to 12:00 AM at Tepco's main office in Tokyo.
 
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  • #13,620
Hope something interesting is discussed on Monday, since there isn't very much new information to talk about these days.

In the meantime, this webcam video shows workers on top of the equipment pit crane of reactor 4, and an additional section of the southern platform around reactor 3 building being put into place. The actual movement into place of this piece occurs about half-way through the video.

 
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