Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Bez999]

This one would be a hell of a lot easier to entomb, as there remains an external shell in place. Pretty much all they have to do is open all internal doors and pump the whole building full of concrete (with a lot of absorbing material in it), with only some of the top floors requiring additional boxing.
If done solidly, they could built new reactors right on top of the boxes thus created, well out of the flooding levels!

 

[javadave]

Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.

I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.

Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.

Here's another article about concrete trucks being sent to the reactors:

http://www.msnbc.msn.com/id/42359020/

 

[Bodge]

Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.

I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.

Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.

Decent radiation graphs:

http://fleep.com/earthquake/

Isn't predicted decay heat somewhat inaccurate if recriticalities are occurring?

 

[Bodge]

This one would be a hell of a lot easier to entomb, as there remains an external shell in place. Pretty much all they have to do is open all internal doors and pump the whole building full of concrete (with a lot of absorbing material in it), with only some of the top floors requiring additional boxing.
If done solidly, they could built new reactors right on top of the boxes thus created, well out of the flooding levels!

Concrete would not be feasible until temperatures go down, also see

realities of entombment:

 

[javadave]

Realities of entombment:

http://i.imgur.com/7MYkR.jpg

bring on the Pharaoh!

 

[Astronuc]

Decent radiation graphs:

http://fleep.com/earthquake/

Isn't predicted decay heat somewhat inaccurate if recriticalities are occurring?

Not necessarily. It would depend on how much positive reactivity is achieved before negative reactivity - Doppler and moderator temperature - would kick in. I don't think we seen any such events.

Most of those activities look encouraging. The plant and areas north are problematic.

 

[hidsuz]

Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.

I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.

Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.

Thanks Astronuc.
So I gather that as long as they keep pouring water in, and they divert the outflow out to sea, we don`t see further explosions or large amounts of radioactive steam/gas which could form clouds and hold us at the mercy of the winds. And that it`s then a matter of time(depending on source heard weeks, months or years though) before full control, and then perhaps no need to encase? Heard from wife that some nanofilter type net has been proposed to put over the reactors.

Been monitoring using these sites:
Ibaraki govt just north of Tokyo http://www.houshasen-pref-ibaraki.jp/present/result01.html
Yokohama govt(basically Tokyo) http://www.city.yokohama.lg.jp/kankyo/saigai/
Kanagawa govt(just west of Tokyo) http://www.atom.pref.kanagawa.jp/cgi-bin2/telemeter_map.cgi?Area=yokosuka&Type=WM
Tokyo govt http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/index-e.html
Private individual Tokyo counter inside with window slightly ajar http://www.ustream.tv/channel/%E3%82%AC%E3%82%A4%E3%82%AC%E3%83%BC%E3%82%AB%E3%82%A6%E3%83%B3%E3%82%BF
Private individual Tokyo http://park30.wakwak.com/~weather/geiger_index.html(measuring inside a wooden house with good ventilation and says reading typically 20% higher outside. Reliable?)

Readings have generally been coming down last several days to basically normal which I believe is due mostly to wind direction here and at Fukushima as well as much lower gaseous output.

 

[TCups]

bring on the Pharaoh!

IF it comes to that as a solution, then I think they should go with rounded or domed containments . . .

http://i.imgur.com/7MYkR.jpg

and paint them pink.

 

[Bodge]

So there is still no way to be sure what is going on inside any of the reactors, but radiation dosage has been trending downwards at the plant and has leveled off in the surrounding areas. Edit: I wonder what today's seawater measurements will find.

 

[Bodge]

IF it comes to that as a solution, then I think they should go with rounded or domed containments . . .

http://i.imgur.com/7MYkR.jpg

and paint them pink.

resisting temptation to photoshop...

 

[NUCENG]

Or. they;re just control rods... ?

http://www.sciencephoto.com/images/download_lo_res.html?id=841700465"

Sorry control rods would have cruciform blades about 12 feet long and about 6 inches wide. Long straight tubes like that could be conduit used to route and protect electrical wiring. There are miiles of conduit in a reactor plant.

 

[Bez999]

Actually, one would assume they'd wish to build new reactors at the same location, so that the rest of the plants can be used again, if that's at all feasible.

Also, what's the possibility of building a concrete shell around the reactor buildings, and filling the whole thing with water, so that remote controlled subs can be used to demolish the thing bit by bit, and leave in place what can be salvaged?

 

[Astronuc]

Thanks Astronuc.
So I gather that as long as they keep pouring water in, and they divert the outflow out to sea, we don`t see further explosions or large amounts of radioactive steam/gas which could form clouds and hold us at the mercy of the winds. And that it`s then a matter of time(depending on source heard weeks, months or years though) before full control, and then perhaps no need to encase? Heard from wife that some nanofilter type net has been proposed to put over the reactors.

Been monitoring using these sites:
Ibaraki govt just north of Tokyo http://www.houshasen-pref-ibaraki.jp/present/result01.html
Yokohama govt(basically Tokyo) http://www.city.yokohama.lg.jp/kankyo/saigai/
Kanagawa govt(just west of Tokyo) http://www.atom.pref.kanagawa.jp/cgi-bin2/telemeter_map.cgi?Area=yokosuka&Type=WM
Tokyo govt http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/index-e.html
Private individual Tokyo counter inside with window slightly ajar http://www.ustream.tv/channel/%E3%82%AC%E3%82%A4%E3%82%AC%E3%83%BC%E3%82%AB%E3%82%A6%E3%83%B3%E3%82%BF
Private individual Tokyo http://park30.wakwak.com/~weather/geiger_index.html(measuring inside a wooden house with good ventilation and says reading typically 20% higher outside. Reliable?)

Readings have generally been coming down last several days to basically normal which I believe is due mostly to wind direction here and at Fukushima as well as much lower gaseous output.

I need to look further into the details. At the moment, I don't believe there will be more hydrogen release. And if the cooling is stabilized, I think the activities should further decrease. I'd like to know the source (radionuclides) producing the activities.

One should limit the exposure of babies, small children, pregnant women, and women of child-bearing age.

As much as possible, drink bottled water, or use a water filter with an activated charcoal filter.

 

[shogun338]

This video contains some ground level footage of the severe damage at the plant .

 

[NUCENG]

To Justguessing:

the top cover of the pressure vessel (big and yellow) shown in this video is the one of reactor No4 and there is nothing abnormal to see it here because the reactor was on maintenance, so the top cover was removed with no fuel in the core. I was talking about reactor No3 where i have the impression to see something ressembling strangely to a cover of pressure vessel.


"the top cover was removed with no fuel in the core" did i say?

(well, are we sure that there was no fuel in the core at No4 by the way? We know that it was down but if my understanding of operations is right, when refuelling they just change maybe one third of the fuel, no?

Could it be possible that there was still fuel physically in the open core when the accident happened? So in this case this fuel may be in the same situation than in the other reactor with a decay rate much more advanced of course, because shut down before tsunami. IS IT POSSIBLE? Then of course it would have been fully under the water at the moment of the tsunami but then what happened after if water leaked from pool? It could have been hot too, don't you think? Could this explain why there is so much damage on building No4, even at the low stages of the building? Didn't we conclude to quickly that the reactor was OFF while some fuel was still inside?

TCUPS: try with an other browser maybe, it works perfectly here (don't know for other members?).

TEPCO Status reports for Fukushima Daiici during the early days clearly stated that the reactors in units 4, 5, and 6 had been defuelled. That is therir system due to long outages. US plants tring to meet 25 day outages shuffle core loads and only remove the spent bundles and replace new fuel.

 

[hidsuz]

I need to look further into the details. At the moment, I don't believe there will be more hydrogen release. And if the cooling is stabilized, I think the activities should further decrease. I'd like to know the source (radionuclides) producing the activities.

One should limit the exposure of babies, small children, pregnant women, and women of child-bearing age.

As much as possible, drink bottled water, or use a water filter with an activated charcoal filter.

Making do with the Brita and other bottled liquids. Bottled water is scarce and will leave for the needy as per your comment above. Maybe the robots will get close enough to find the source but then again TEPCO will have to be willing to release the pertinent details, not a given.

 

[razzz]

Link was working for me but here it is again with some quote outtakes.

http://chronicle.augusta.com/latest-news/2011-03-31/srs-concrete-pump-heading-japan-nuclear-site"

...“The bottom line is, the Japanese need this particular unit worse than we do, so we’re giving it up,” said Jerry Ashmore, whose company, Augusta-based Ashmore Concrete Contractors, Inc., is the concrete supplier for the MOX facility.

The 190,000-pound pump, made by Germany-based Putzmeister has a 70-meter boom and can be controlled remotely, making it suitable for use in the unpredictable and highly radioactive environment of the doomed nuclear reactors in Japan, he said...

...The pump was moved Wednesday from the construction site in Aiken County to a facility in Hanahan, S.C., for minor modifications, and will be trucked to Atlanta’s Hartsfield Airport, where it will be picked up by the world’s largest cargo plane, the Russian-made Antonov 225, which will fly it to Tokyo...

...Initially, the pump from Savannah River Site, and another 70-meter Putzmeister now at a construction site in California, will be used to pump water—and later will be used to move concrete.

“Our understanding is, they are preparing to go to next phase and it will require a lot of concrete,” Ashmore said, noting that the 70-meter pump can move 210 cubic yards of concrete per hour.

Putzmeister equipment was also used in the 1980s, when massive amounts of concrete were used to entomb the melted core of the reactor at Chernobyl.

In addition to the equipment now at Fukushima and the two 70-meter pumps being moved from the U.S., a contractor in Vietnam has given up a 58-meter pump so it can be diverted to Japan, and two 62-meter pumps in Germany were loaded on Wednesday for transport to Tokyo.

Ashmore officials have already notified Shaw AREVA MOX Services, which is building the MOX plant for the U.S. Department of Energy’s National Nuclear Security Administration, that the pump was being moved and will not be returned. “It will be too hot to come back,” Ashmore said...

 

[83729780]

This video contains some ground level footage of the severe damage at the plant .

2:18 to 2:28, something is glowing orange inside the third story of reactor 4

 

[TCups]

2:18 to 2:28, something is glowing orange inside the third story of reactor 4

The challenge, to me, seems to be to find any frame from the video where there isn't something glowing orange.

 

[Joe Neubarth]

@bez999


my understanding is that the equipment pool is used for storage of the reactor vessel cap (not the drywell cap) during the refueling process. It has been suggested to me by astronuc the equipment on the floor at the back left corner might be the steam dryer (would that be radioactive?).

it is now!

 

[Joe Neubarth]

Concrete would not be feasible until temperatures go down, also see

realities of entombment:

They could take hundreds of busloads of tourists to see the site and marvel at the fortitude and dedication of the Japanese people. Meanwhile the engineers who placed those diesels where they could be immersed in salt water like they were, thus giving us this horrific accident SHOULD be entombed at the top of the pyramids.

 

[Emreth]

2:18 to 2:28, something is glowing orange inside the third story of reactor 4

I think it's the crane inside.

 

[intric8]

For the NP's here - just a simple question for the edification of those of us much less knowledgeable about the subject - Is covering in concrete a bad idea? What are the most likely complications?

 

[|Fred]

I'm now 95% confident that this is what we are seeing (mind the color is green on the japanese plant and not yellow)
[PLAIN]http://k.min.us/ik0PBa.jpg

as far as the missing top part of the crane I would say that I have a 40% confidence it is there see attachement

 

[jensjakob]

I agree that the crane is there in #3.

Analyzing this image - I wonder if it has fallen of the tracks, and is laying flat across the center of the building (and the CV concrete lid)

 

[AtomicWombat]

I'm now 95% confident that this is what we are seeing (mind the color is green on the japanese plant and not yellow)

as far as the missing top part of the crane I would say that I have a 40% confidence it is there see attachement

I agree and I think you can be more than 40% confident about that.

A few points:
1) There is clearly water (& debris) in the SFP, indicating no major breach or leak.

2) The reactor mouth is completely covered by debris - mostly the overhead crane, which now rests on the operating floor.

3) The roof framework that survived the blast seems to have been shielded by the overhead crane - obviously a robust structure capable of lifting about 100 tons.

4) Some speculation. The tangled green mess on the north side (see photo) may be the remains of the fuel handling machine. An odd position, but it was an odd day as they clearly were loading spent fuel casks. This would involve the overhead crane and at some point may require moving the fuel handling machine completely out of the way.

Here is a fascinating video of this procedure with several other fascinating videos in the "suggestions":
http://www.youtube.com/watch?v=rh6FeQWuhCs"

 

[|Fred]

With a little more time .. and tweak in the image... I'm getting closer to 70% confidence in the top crane
high res picture on the link (click a on the picture once on minus)
http://min.us/mvknESi

 

[jensjakob]

With a little more time .. and tweak in the image... I'm getting closer to 70% confidence in the top crane
high res picture on the link (click a on the picture once on minus)
http://min.us/mvknESi

Agree. Crane is there.

But - what happened to the north-side of the building? Looks severely damaged. Also looks like a ring - top of a storage tank with the lid blown off?

What kind of storage tanks are placed to the north of the reactor - inside the building?

Btw - great tip with the color-change, how did you do it ? Green hueing?

 

[Demidrol]

With a little more time .. and tweak in the image... I'm getting closer to 70% confidence in the top crane
high res picture on the link (click a on the picture once on minus)
http://min.us/mvknESi

Yellow pieces top and bottom of the reactor number 3. This can be pieces drywell ?

 

[AtomicWombat]

I post here a series of screenshots of the video showing the explosion of reactor 3. Take the stack vent (the white "antenna") as a reference, it is perfectly aligned with the left edge of the reactor N°3 building.

Then the vertical grey burst continues to rise very high in the sky (i estimated at around 500m based on the fact that the reactor buiding is around 50 meters high). But it's difficult to see where are the big chunks at the top.

For reference the complete video is here:


PERSONAL CONCLUSIONS: to me pictures of the debris correlate with pictures of the explosions (what a scoop hey!). On the south side at the top we see the place of the first flash above the pool, with a big hole and around the metal is heavily bent. On the North west side, this has been the place of the big vertical burst: heavy destruction of the building, with some holes still visible from the bottom. The metal structure of the roof which stays in the middle seems to have been displaced towards the south by the vertical burst. The south side of reactor n°2 has been crippled by the lateral debris projected by the lateral burst on the North side at N°3. We can also see that Building n°3 is more heavily damaged on its west side than on its east side (one level more still there).

Hi jlduh,

I've had a close look at the stills & the video and done some calculations. The main blast seems to align with the stack. The stack also seems to line up well with the corner of the building (corresponding to the join of the west and south walls). These two walls are about 45 metres and 35 metres long respectively, although at the viewing angle they appear to be of equal length. Assuming the west wall points due north I calculate the angle to sight to be 40 degrees to the west of due north. This is consistent with the main blast originating close to the centre of the building near the back where the reactor mouth is.

As to the height of the blast. I timed how long it took from the initial explosion for heavy debris that fell to the left to hit the ground. It is 14-15 seconds. It reached maximum height in about half this time - there is no evidence of a "rocket effect". Using Newton's Laws of Motion this gives an estimated height of 0.5*g*t^2, where t is half the total time of flight. This gives 5*(7)^2 = 245 metres or 5*(7.5)^2 ~ 280 metres. The building height (50-60 metres) can be added if you like. So I'd say the heavy debris reached a height of about 250 metres above the roof of the building, or about 300 metres total.

The "launch velocity" was about 70-75 m/s or about 250-270 km/h, so air resistance can be neglected for large dense objects.