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.
  • #14,176
Filling in more questions about timing, this time in relation to fuel removal from reactor 4 pool.

I think the last we heard about this was a pool & reactor debris survey from August:

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130809_07-e.pdf

According to that the debris removal work should have started in late August, and I expect that if they don't get stuck, we will hear about the next phase before the end of this year.

edited to add that schedule can be seen in this document from later in August, after they formed a plan based on the debris survey I just mentioned:

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130826_07-e.pdf

Fuel removal currently scheduled to start mid-november according to that.
 
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  • #14,177
Rive said:
Well... Once they will be able to remove Sr (and some other elements) they should dump that water somewhere. Even if I prefer places where it'll be isolated for some time (this includes some natural reservoirs deep below), it would do practically nothing even if they mix it well in the ocean.

Logic would suggest park it in a tanker, freeze it and send it to someplace really cold. It should not be too hard to keep it as an ice cube for a century or two somewhere in a polar region.
After that it should not matter if the tanker rusts out beneath the cargo.
 
  • #14,178
I'd suggested a line of old Liberty Ship boilers to distill it. Demineralizers are wonderful but you are left with a LOT of contaminated resin. And seawater wrecks demineralizer resins quickly.
Boiler sludge would be more compact i'd think.
 
  • #14,179
oops double post - how'd that happen?

removed
 
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  • #14,180
nikkkom said:
I guess there isn't significant difference in concentration of D compared to natural water.

As it seems, you are right:
http://www.nap.edu/openbook.php?record_id=9263&page=113
So it cannot be used as a raw material for the heavy water industry.

etudiant said:
Logic would suggest park it in a tanker, freeze it and send it to someplace really cold. It should not be too hard to keep it as an ice cube for a century or two somewhere in a polar region.
After that it should not matter if the tanker rusts out beneath the cargo.

My idea is to pump it down to some geologic formation where the water moves only slowly.
But the 'rust in peace' is also good. It has to be 'out of the way' only for a hundred year or so.
 
  • #14,182
http://www3.nhk.or.jp/news/genpatsu-fukushima/20130918/index.html Damages such as cracks were found in 8 locations at elevation 66 m on the unit 1/ unit 2 stack (full height, about 120 m). The cracks are thought to have been caused by the March 2011 earthquake. Tepco will check the resulting earthquake resistance against future earthquakes. The stack is presently unused. As the radiation in the stack vicinity is as high as 10 Sv/hour Tepco is studying how to perform a detailed survey.

http://www.tepco.co.jp/nu/fukushima-np/handouts/2013/images/handouts_130918_13-j.pdf Japanese language handout with picture.
 
  • #14,183
Thanks to everyone for the updates.


I found this on the TEPCO site, dated July 25th

Progress Status and Future Challenges of the Mid-and-long-Term Roadmap toward the Decommissioning of Units 1-4

http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/images/d130725_01-e.pdf



I also found this on the NRA site.

Updated Status of Fukushima Daiichi Nuclear Power Station - Sept. 16

http://www.nsr.go.jp/english/data/20130917_presentation.pdf [Broken]
 
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  • #14,184
5.3 earthquake + thanks

tsutsuji said:
<snip>Tepco will check the resulting earthquake resistance against future earthquakes. <snip>

It appears Tepco went with live testing today!
http://earthquake.usgs.gov/earthquakes/eventpage/usb000jw8u#shakemap

Seriously, probably not much of an issue...

Thanks to everyone for continuing to track this evolving disaster, especially tsutsuji and others that do translations and reading between the lines.
 
  • #14,185
New method reduces analysis time of radioactive strontium

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201309190058 [Broken]
 
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  • #14,186
LabratSR
New method reduces analysis time of radioactive strontium

Although the conventional technique has superior analytical sensitivity, with only a minimal amount of components needed to be reliably detected in sample, the process took from two to four weeks
http://ajw.asahi.com/article/0311dis...AJ201309190058 [Broken]

has long existed in the "iron" and running in 30 minutes qualifies.

http://akp.com.ua/en/index.php?opti...eb-01-150en&catid=71:bettaspectren&Itemid=106
 
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<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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