Japan Earthquake: Nuclear Plants at Fukushima Daiichi

In summary: RCIC consists of a series of pumps, valves, and manifolds that allow coolant to be circulated around the reactor pressure vessel in the event of a loss of the main feedwater supply.In summary, the earthquake and tsunami may have caused a loss of coolant at the Fukushima Daiichi NPP, which could lead to a meltdown. The system for cooling the reactor core is designed to kick in in the event of a loss of feedwater, and fortunately this appears not to have happened yet.
  • #13,581
tsutsuji said:
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120803_02-e.pdf Investigation on the Misconnection of Thermometer Wiring at Fukushima Daiichi Nuclear Power Station :


What are we supposed to do with this "set value"? Isn't the water level more likely to be very low, a few cm above the bottom like at unit 2?

I didnt really understand that one myself when I read about it, especially since it also says they've set the reactor 2 one to an even higher level. For all intents and purposes I believe such instrumentation is useless right now anyway, will just have to wait for actual surveys of DW conditions at the other reactors.
 
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  • #13,582
Tepconium-311 said:
Hmm, could the pipe simply have molten and welded shut?

There is more about the alternative thermometer insertion plan and related assumptions in the following document.
 
  • #13,583
tsutsuji said:
The 8th mid & long term meeting was held on 30 July 2012:

3-1 Cooling by closed loop water injection

http://www.meti.go.jp/earthquake/nuclear/pdf/120730/120730_01g.pdf Unit 2 alternative thermometer installation progress status

1) Previous related topics:

1 March 2012 report ( https://www.physicsforums.com/showpost.php?p=3795578&postcount=12465 part 1, https://www.physicsforums.com/showpost.php?p=3796935&postcount=12485 part 2, https://www.physicsforums.com/showpost.php?p=3799356&postcount=12492 part 3)

23 April 2012 report: https://www.physicsforums.com/showthread.php?p=3939578#post3939578 (insertion and freezing mock-ups)

28 May 2012 government-Tokyo Electric mid and long term response committee, steering committee (6th meeting): https://www.physicsforums.com/showt...ighlight=alternative+thermometers#post3941037 Results of the surveys on location concerning the environment improvement for the purpose of installing alternative thermometers in unit 2's RPV

01 June 2012 videos:

http://photo.tepco.co.jp/en/date/2012/201206-e/120601_02e.html [Broken] "Decontamination around the truck bay door at Unit 2, Fukushima Daiichi NPS" (released on 1 June 2012)

http://photo.tepco.co.jp/en/date/2012/201206-e/120601_01e.html [Broken] "Mock-up test to check the insertability of the alternative thermometer at Unit 2" (released on 1 June 2012)

25 June 2012 Mid & long term meeting : Unit 2 alternative thermometer installation progress status: https://www.physicsforums.com/showpost.php?p=3984965&postcount=13523

12 July 2012: Checking SLC pipe integrity handout 1: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120712_05-e.pdf
13 July 2012: Checking SLC pipe integrity handout 2: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120713_04-e.pdf

2) Translation:

01/11
attachment.php?attachmentid=49641&stc=1&d=1344361658.png

02/11
attachment.php?attachmentid=49642&stc=1&d=1344361658.png

03/11
attachment.php?attachmentid=49643&stc=1&d=1344361658.png
 

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  • #13,584
Translation:

04/11
attachment.php?attachmentid=49644&stc=1&d=1344361814.png

05/11
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06/11
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  • #13,585
Translation:

07/11
attachment.php?attachmentid=49647&stc=1&d=1344362022.png

08/11
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09/11
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  • #13,586
Translation:

10/11
attachment.php?attachmentid=49650&stc=1&d=1344362185.png

11/11
attachment.php?attachmentid=49651&stc=1&d=1344362185.png
 

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  • #13,587
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120807/index.html It was found by viewing the teleconference videos that on 12 March 2011 after the unit 1 explosion, late in the night an official said "disband !" and almost all high rank officials left the main office response center that was supposed to support Fukushima Daiichi during the accident. Tepco explained that although high rank officials had left, "technicians were remaining and were responding".http://ajw.asahi.com/article/0311disaster/fukushima/AJ201208070052 [Broken] "The following scene, from March 14, 2011, highlights the difficulties between those at the plant trying to deal with the emergency and executives at TEPCO's Tokyo headquarters trying to provide advice"

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201208070055 [Broken] "TEPCO's edited video sheds little light on truth"
 
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  • #13,588
etudiant said:
Has there been any analysis of the seawater contamination incident at the Chubu Electric Hamaoka #5 reactor?
According to this article posted Aug 4, 2012 at Atomic Power Review:
http://atomicpowerreview.blogspot.com/2012/08/hamaoka-no-5-seriously-contaminated.html
there was a pipe failure in the main condenser during shutdown, so that a lot of secondary cooling circuit sea water contaminated the reactor.
In the current environment, that unit is probably a writeoff, but there are surely some real lessons to be learned if a deliberate shutdown can cause such a damaging failure to occur.

Indeed, how rotten must this nuclear plant look inside now, if immediate photos after discovery already remind of scrap metals yard.
See here for images!

tsutsuji said:
Translation:

04/11
[...]
05/11
attachment.php?attachmentid=49645&stc=1&d=1344361814.png

06/11
[...]

"The obstruction is inferred to be inside the RPV."
This is very interesting.

Let's remember how RPVsapparently fail.
Look at this (the sources are reputable, I hope) which I found here.
attachment.php?attachmentid=49699&stc=1&d=1344547811.jpg

Let's say it in a very prosaic manner: they seem to p!ss, instead of sh!tting.

I mean, look at Swedish experiment still photo. Hottest and softest area first gets penetrated. It flows, it doesn't drop.

What if corium sploshing out of vessel warmed up pipe, making a (near) perfect weld in combination with containment overpressure?

(NUCENG, any idea?)

(BTW, tsutsuji, thank you again very much for translating this mega-interesting piece of information!)
 

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  • #13,589
Those failures tests are on vessels with considerably less mass and wall thickness and a bone dry simulated RPV. It also doesn't have the myriad of protrusions that the normal RPV has. I'm not sure you can draw much from that test when looking at fukushima.
 
  • #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 [Broken]

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 "theres 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.

:grumpy:
 
  • #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.
 
<h2>1. What caused the Japan earthquake and subsequent nuclear disaster at Fukushima Daiichi?</h2><p>The Japan earthquake, also known as the Great East Japan Earthquake, was caused by a massive underwater earthquake that occurred on March 11, 2011. The earthquake had a magnitude of 9.0 and was the strongest ever recorded in Japan. The earthquake triggered a massive tsunami, which caused extensive damage to the Fukushima Daiichi nuclear power plant and led to a nuclear disaster.</p><h2>2. What is the current status of the nuclear reactors at Fukushima Daiichi?</h2><p>As of now, all of the nuclear reactors at Fukushima Daiichi have been shut down and are no longer in operation. However, the site is still being monitored for radiation levels and there is an ongoing effort to clean up the radioactive materials that were released during the disaster.</p><h2>3. How much radiation was released during the Fukushima Daiichi nuclear disaster?</h2><p>According to the International Atomic Energy Agency, the Fukushima Daiichi nuclear disaster released an estimated 10-15% of the radiation that was released during the Chernobyl disaster in 1986. However, the exact amount of radiation released is still being studied and debated.</p><h2>4. What were the health effects of the Fukushima Daiichi nuclear disaster?</h2><p>The health effects of the Fukushima Daiichi nuclear disaster are still being studied and monitored. The most immediate health impact was the evacuation of approximately 160,000 people from the surrounding areas to avoid exposure to radiation. There have also been reported cases of thyroid cancer and other health issues among those who were exposed to the radiation.</p><h2>5. What measures have been taken to prevent future nuclear disasters in Japan?</h2><p>Following the Fukushima Daiichi nuclear disaster, the Japanese government has implemented stricter safety regulations for nuclear power plants and has conducted stress tests on all existing plants. They have also established a new regulatory agency, the Nuclear Regulation Authority, to oversee the safety of nuclear power plants. Additionally, renewable energy sources are being promoted as a more sustainable and safer alternative to nuclear power in Japan.</p>

1. What caused the Japan earthquake and subsequent nuclear disaster at Fukushima Daiichi?

The Japan earthquake, also known as the Great East Japan Earthquake, was caused by a massive underwater earthquake that occurred on March 11, 2011. The earthquake had a magnitude of 9.0 and was the strongest ever recorded in Japan. The earthquake triggered a massive tsunami, which caused extensive damage to the Fukushima Daiichi nuclear power plant and led to a nuclear disaster.

2. What is the current status of the nuclear reactors at Fukushima Daiichi?

As of now, all of the nuclear reactors at Fukushima Daiichi have been shut down and are no longer in operation. However, the site is still being monitored for radiation levels and there is an ongoing effort to clean up the radioactive materials that were released during the disaster.

3. How much radiation was released during the Fukushima Daiichi nuclear disaster?

According to the International Atomic Energy Agency, the Fukushima Daiichi nuclear disaster released an estimated 10-15% of the radiation that was released during the Chernobyl disaster in 1986. However, the exact amount of radiation released is still being studied and debated.

4. What were the health effects of the Fukushima Daiichi nuclear disaster?

The health effects of the Fukushima Daiichi nuclear disaster are still being studied and monitored. The most immediate health impact was the evacuation of approximately 160,000 people from the surrounding areas to avoid exposure to radiation. There have also been reported cases of thyroid cancer and other health issues among those who were exposed to the radiation.

5. What measures have been taken to prevent future nuclear disasters in Japan?

Following the Fukushima Daiichi nuclear disaster, the Japanese government has implemented stricter safety regulations for nuclear power plants and has conducted stress tests on all existing plants. They have also established a new regulatory agency, the Nuclear Regulation Authority, to oversee the safety of nuclear power plants. Additionally, renewable energy sources are being promoted as a more sustainable and safer alternative to nuclear power in Japan.

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