Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[jlduh]

Also, i read in french here that steam has been seen again Friday morning (8h00 in the morning in Japan) above reactor N° 3, and that was an information from TEPCO and that it was seen from a camera (probably Tepco webcam).

http://www.lemonde.fr/planete/artic...ait-au-dessus-du-reacteur-3_3476943_3244.html

But i don't see any info about that in english elsewhere (maybe some in japanese?)?

Any news about this? Was it filmed and saved somewhere on the net?

 

[Rive]

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130913_01-e.pdf

What's most interesting:
- graph on page 24: the water flow direction might be even now reversed, it's flowing in from the ocean, at least at that point
- first graph on page 17

 

[LabratSR]

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130913_01-e.pdf

What's most interesting:
- graph on page 24: the water flow direction might be even now reversed, it's flowing in from the ocean, at least at that point
- first graph on page 17

Another update from TEPCO and yet again, absolutely nothing covered other than the water issues. Status of the clean-up of the units? Fuel removal from Unit 4 SFP? Removal of the Unit 1 cover? Location of the cores? And on and on.

Thanks for posting.

 

[jlduh]

Hummm, this one is also of "great caliber": to dismantle one tank leaking, they have to dismantle an other one before because tanks are overcrowded!

http://fukushima-diary.com/2013/09/...smantled-because-of-no-space-among-the-tanks/

Well, 300 tanks assembled, if some start to leak i let you imagine the tremendous work/mess to fix it!

 

[jlduh]

Hummm, this one is also of "great caliber": to dismantle one tank leaking, they have to dismantle an other one before because tanks are overcrowded!

http://fukushima-diary.com/2013/09/...smantled-because-of-no-space-among-the-tanks/

Well, 300 assembled tanks, if some start to leak i let you imagine the tremendous work/mess to fix it!

 

[a.ua.]

Fixing Fukushima’s water problem

Lake H. Barrett

 

[zapperzero]

I have wasted a few minutes of my life to skim-read mr Barrett's creation. Fluff and handwavium.

 

[Rive]

Another update from TEPCO and yet again, absolutely nothing covered other than the water issues. Status of the clean-up of the units? Fuel removal from Unit 4 SFP? Removal of the Unit 1 cover? Location of the cores? And on and on.

The water issues are, which actually most concerned by 'the public'.

OW no (really) new information about the other topics. U3 top clean up is almost down to the smaller fragments, but the operation is suspended due the steam from under the ceiling crane beam. They are planning the decontamination and the shielding.

U4 SFP cleanup work might start in the next month if everything works fine. Also that month they plan to go on with the 'core lookup' endoscopic missions.

I don't know about any plan to remove the cover of U1.

But all this is just based on small hints dispersed all over some dozen documents.

 

[Rive]

I have wasted a few minutes of my life to skim-read mr Barrett's creation. Fluff and handwavium.

For first read, yes.
However I will go on for a second read - maybe there will be some hints.

 

[zapperzero]

For first read, yes.
However I will go on for a second read - maybe there will be some hints.

Ah yes. That's why he's advocating the dumping of contaminated water. Okay.

 

[Rive]

Ah yes. That's why he's advocating the dumping of contaminated water. Okay.

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. But... ... we know about the Tritium concentration of that water, but what about Deuterium? I wonder, would it worth to process (and sell) it?

 

[nikkkom]

But... ... we know about the Tritium concentration of that water, but what about Deuterium? I wonder, would it worth to process (and sell) it?

I guess there isn't significant difference in concentration of D compared to natural water.

 

[LabratSR]

Thanks, here is the TEPCO release about Unit 1

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130509_07-e.pdf

 

[Rive]

Some video tour?

http://photo.tepco.co.jp/en/date/2013/201309-e/130917-03e.html

Ps.: it's almost useless. The only new information I could spot was that the remaining concrete beams on U3 top are now removed.

 

[SteveElbows]

Another update from TEPCO and yet again, absolutely nothing covered other than the water issues. Status of the clean-up of the units? Fuel removal from Unit 4 SFP? Removal of the Unit 1 cover? Location of the cores? And on and on.

Thanks for posting.

Others have pointed out documents that give some clue as to timescales for some of these tasks, though I'd have to go back over a mess of documents to fill in some of the remaining gaps. I'll return to some in the coming hours or days but for now I will just deal with core location surveys.

Reactor 3 needs more decontamination inside the reactor building before they do any useful surveys. We hear very little about reactor 1. Reactor 2 is where there has been the most progress, including in recent months.

The last thing we learned about reactor 2 is not many pages ago on this thread, with the last survey revealing a rate of 36 Sv/h just outside the pedestal opening. But now they have to look at the results & tricky operating conditions encountered during that survey in order to plan the next survey which will hopefully go inside the pedestal area and give a better idea about core location.

One other thing I may have learned from that survey, if all the documents & diagrams were accurate, is that the location of the full 'door' into the pedestal area, is to the south-east. This is based on an assumption that this door, which was of interest to those wondering about molten core flow or splashing outside of the pedestal area, is opposite the pedestal opening that they got close to in this survey (this surveyed opening is more like a window than a door, and is used to replace control rod drivers).

Anyway, when trying to guesstimate core location at this stage, apart from that 36 Sv/h figure for reactor 2, and the various theoretical analysis done with models, I think the only other thing we have to go on is the state of the torus rooms at the three reactors. It is tempting to suggest that radiation dose levels in the torus rooms of reactors 2 & 3 are not spectacular enough to promote theories about core migrating away from the drywell containment in these reactors. But the very limited surveying possible at reactor 1 torus room, along with the levels of radiation measured there, may hint at a more interesting story for that reactors core. But I expect it would be grossly premature to make any conclusions based on this, its just what I'm throwing out there during the long wait for more substantial data. Thoughts more than welcome, including whether the 36 Sv/h reading near the pedestal opening of reactor 2 is the sort of reading we might expect if most of the core was either in the bottom of the RPV or the pedestal area of this reactor.

 

[SteveElbows]

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.

 

[etudiant]

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.

 

[jim hardy]

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.

 

[jim hardy]

oops double post - how'd that happen?

removed

 

[Rive]

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.

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.

 

[a.ua.]

Removal of the Unit 1 cover?

Thanks for posting.

Perhaps, if you look through the periscope of this will be seen something.
http://photo.tepco.co.jp/date/2013/201309-j/130918-01j.html

 

[tsutsuji]

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.

 

[LabratSR]

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

 

[StrangeBeauty]

5.3 earthquake + thanks

<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.

 

[LabratSR]

New method reduces analysis time of radioactive strontium

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201309190058

 

[a.ua.]

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

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

 

[Greg Bernhardt]

Please continue discussion in Part 2
https://www.physicsforums.com/showthread.php?t=711577