What happened at Fukushima Daiichi during the Japan earthquake?

[flyingblind]

What about this strange idea ?
[PLAIN]http://img864.imageshack.us/img864/770/7d39a2e665024e3f8856f31.jpg[/QUOTE]

I don't think so
http://cryptome.org/eyeball/daiichi-npp/pict6.jpg"

 

[|Fred]

I think I just found our alleged Ballistic FHM
http://www.houseoffoust.com/fukushima/tour/R3_equipment.jpg
Now we just have to figure out what it is and why it's there
thanks to http://www.houseoffoust.com/ who did some nice digging

edit:
it is located on the north wall on the west of the utility pool at the time of the picture, actually more or less where it is now

edit2:
troublesome part the picture is subtitle 原子炉上部の蓋を外す機械
Remove the lid at the top of the reactor equipment (Ill take those legend with a grain of salts )

this look like the tranfert cast openining located on the south west corner
[URL]http://www.newcs.futaba.fukushima.jp/05-20000519/f1-16.JPG[/URL]



Unit 3 taken from the south west corner
notice the FHM crane on the right inside of the picture
the reactor round concrete slab in the center
and the infamous former ballistic machine on the left of the picture
http://www.houseoffoust.com/fukushima/tour/r3_floor.jpg

 

[cphoenix]

40 feet of water has a static head of 17.3 PSI, just over 1 ATM. And, of course, that is only the bottom of the pool, the mid-level would be half that. So, the amount of energy that could be stored there is a lot less than you give numbers for.

Without some mechanism to force the water to remain still and not convect, I just don't see how this can happen. A very messy boiling mess is quite possible when the active cooling fails, but great superheating and then explosive vaporisation just defies logic. But, maybe with superpure water, it is possible. Not sure how pure the water was after the earthquake.

Jon

I already took out a factor of 1/2 in my initial post on the subject. And I acknowledge that 1/10 kiloton is what you get if you manage to stratify the water in the pool and heat it to maximum. But even if you trap just a few tens of cubic meters near the bottom, you still get hundreds of pounds of TNT. 1E6 g * 25 C * 4 J/gC = 1E8 J = 100 MJ. That's 24 kg TNT equivalent per cubic meter, or ~100 kg per square meter of rack covered.

The water could be forced to remain still quite easily, by dropping something flat on top of the racks. 4 cubic meters of water at 125 C has a buoyancy of 21 kg vs. 100 C water. That's only 21 kg/m^2 to hold it down, or 0.03 PSI driving any convection. And it wouldn't have to go all the way to 125 C to store a lot of energy; a 1 m^2 piece of material weighing the equivalent of 10 kg/m^2 underwater would create 50 kg of TNT equivalent.

25 C is not great superheating. It's pretty moderate... until you multiply it by many tons of water. I'm not sure if I should say "superheating" for water that is above 100 C due to pressure.

Someone mentioned that the racks might have fallen to the floor of the pool, which would also reduce convection. If the pipes were open at the top, but not at the bottom, and if there were no bubbles (not hot enough yet - below 125), would convection still be sufficient to remove the heat?

Someone else asked if there would be water in the pool after a geyser explosion. I'd expect that if just a small area "cooked off" then it might go straight up rather than pushing a lot of water to the sides and out of the pool. Some would slosh out, of course. But you could still have the fuel rods covered after a pretty major steam release.

Chris

 

[|Fred]

I don't understand how this floor layout of unit 3 fit anything at hand.. may be if someone could caption it

 

[cphoenix]

If the SFP did flash to steam, it would likely have been an unmistakable event, with a HUGE steam cloud, and water splashed over the entire facility. Anyone outside would have had horrible scalding, and probably anyone in the building at the time, also. The water everywhere would have taken a couple hours to evaporate. So, I think a massive flashing of tons of water to steam would have been clearly different from what we did see, and therefore that isn't what happened.

Also, this would have removed a bunch of the water in the pool, although maybe not completely emptied it, if this stratification theory is possible (I don't believe it is). So, then there WOULD have been major damage to the fuel in the pool, which they say is not so.

Jon

If only part of the racks were covered, or otherwise unable to convect, then the amount of steam might have been small enough to over-pressure the building but not fill the building with steam. A ton of steam is only about a 10-meter cube.

Perhaps I made a mistake by talking about total stratification in my first post, to find an upper bound for energy release. Let's focus now on the very plausible idea that some fraction of the water inside the fuel racks was not able to convect, because a rack was either damaged or covered by something flat that fell in the pool.

You get up to 24 kg of TNT per cubic meter of water, assuming it reaches maximum temperature before it burps. That is about 44 kg of steam, or 73 m^3 of steam at 1 atm.

Depending on how much of the fuel rack was unable to convect, we can make the explosion as small or as large as we need to in order to explain the observations. This may seem too convenient, but I don't see any obvious constraint on the problem.

Chris

 

[MiceAndMen]

troublesome part the picture is subtitle 原子炉上部の蓋を外す機械
Remove the lid at the top of the reactor equipment (Ill take those legend with a grain of salts )

They probably don't have workers manually using big socket drivers, so maybe it is used to tighten and loosen the nuts that screw down on the studs around the RPV circumference that hold the cap on. Like a big torque wrench. The "U" shaped things hanging on it may be flexible hydraulic lines, but I'm not sure.

 

[elektrownik]

Second layer of fuel rods in SFP 3 ??
[URL]http://www.houseoffoust.com/fukushima/tour/R3_sfp6.jpg[/URL]

 

[MiceAndMen]

I don't understand how this floor layout of unit 3 fit anything at hand.. may be if someone could caption it

From http://www.newcs.futaba.fukushima.jp/05-20000519/f1-13.JPG
and the 8th picture on http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

The reactor buildings are square at ground level (and below), but that aspect is not carried upward the entire height of the building.

 

[|Fred]

From http://www.newcs.futaba.fukushima.jp/05-20000519/f1-13.JPG
and the 8th picture on http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

View attachment 34604

The reactor buildings are square at ground level (and below), but that aspect is not carried upward the entire height of the building.

I figured that much ;) its more the color coding that puzzle me what does the orange means Cranes ? the main one should be crossing the building , etc etc

 

[MiceAndMen]

I figured that much ;) its more the color coding that puzzle me what does the orange means Cranes ? the main one should be crossing the building , etc etc

My guess is the colors represent areas with different protocols for fire emergencies. Maybe someone would be kind enough to translate the chart on the left side.

 

[Rive]

I don't understand how this floor layout of unit 3 fit anything at hand.. may be if someone could caption it

IMHO it's an ABWR design and not related to the Unit1-Unit6. The one with the reactor modell is also an ABWR (maybe the same). Possibly related to the would-be Unit7-8?

 

[rowmag]

From the coloring and shape, I am beginning to suspect that it is concrete wall panel from #4's own wall, that somehow got blown upwards to land on its own roof.

No, the simplest explanation is the correct one. It is a piece of the roof[...]

Hmm, you're right! The corrugation pattern on the underside is visible in the following photo from houseoffoust.com:

http://www.houseoffoust.com/fukushima/LARGE4_1.jpg

Another beautiful theory slain by ugly facts.

 

[|Fred]

nope it is definitively the reactor 3 as subtitle on the original page
http://www.newcs.futaba.fukushima.jp/05-20000519/index41.html

 

[Rive]

What about this strange idea ?
[PLAIN]http://img864.imageshack.us/img864/770/7d39a2e665024e3f8856f31.jpg[/QUOTE]

Check the second T-Hawk video about that debris laying on the pipes. I think it's a wall panel from the closest wall. One of the upper ones.

 

[rowmag]

I think I just found our alleged Ballistic FHM
http://www.houseoffoust.com/fukushima/tour/R3_equipment.jpg
Now we just have to figure out what it is and why it's there
thanks to http://www.houseoffoust.com/ who did some nice digging

edit:
it is located on the north wall on the west of the utility pool at the time of the picture, actually more or less where it is now

edit2:
troublesome part the picture is subtitle 原子炉上部の蓋を外す機械
Remove the lid at the top of the reactor equipment (Ill take those legend with a grain of salts )

It says, "Machine for removing the cover of the upper part of the reactor."

Sounds like what MiceAndMen suggested.

 

[Jorge Stolfi]

What about this strange idea ?
[PLAIN]http://img864.imageshack.us/img864/770/7d39a2e665024e3f8856f31.jpg[/QUOTE]

I would straighen the red arrows.The plate that is stuck into the #4 roof spans the whole width of of the building (if not more). Note that its West end sank deeper into the roof, and is almost hidden from view.

As for the orange arrows, that debris looks like a chunk of #4's concrete skin, and probably came from the East wall. There seems to have been an explosion in the lower floors of #4 that popped the lower tier of concrete panels (below the main floor) outwards. (Either that, or the hypothetical second explosion at #3 basted through the center panel of the North wall, on that same floor, and came out through the other walls.) There are other similar bits of concrete lying on the ground, next to the West and East walls of #4.

 

[clif]

Stacking in a SFP?

ＭＯＸ燃料を真上から (Fuel from right above)

MOX would mean reactor #3

The objects on the right appear to be a level higher then those on the left.

Image from here

http://www.newcs.futaba.fukushima.jp/05-20000519/index41.html"

 

[rowmag]

I don't understand how this floor layout of unit 3 fit anything at hand.. may be if someone could caption it

Very blurry and cut off, but here's a stab:

Light Blue: Service areas and passageways
Orange: Reactor components
Dark green: Turbine room
Dark blue: can't make it out
Yellow: some electrical equipment -- distribution panels?

Shape looks like it could be Unit 3 to me, at the level of the foundations.

 

[razzz]

A construction or design flaw as the roof is suppose to scatter and not harm the main frame. That portion of the roof blew up whole and came down whole folding the parapet inward and taking a whole row of cross-members down. Had to have some airtime. Guess we will never see that explosion on real time video.

I agree the oddball green machine is an overgrown hydraulic torque wrench to batten down the hatches.

 

[rowmag]

Ok, I am going to go back to wondering if hydrogen got into Building 4 from somewhere else. Why? Because of the 5 meters of water which were found in the basement there. Yomiuri reports that the water is contaminated, though they don't know how badly, so that argues against the tsunami theory mentioned on the news last night, I think. And I doubt it is from SFP4.

If there is a path for contaminated water from one of the other reactors, then perhaps there is also one for hydrogen.

Don't suppose anyone has any underground trench or conduit maps?

 

[|Fred]

Embryo Proposition for unit 3 chain of event, aka Bang Bang Bang
(nothing to do with the audio track that I'm I'm not taking into consideration)


Bang 1 : First explosion, is a regular "clean" explosion with an horizontal plan main component. Walls gave out

Bang 2 : Is not explosion it's the hudge heavy top crane falling down on the operating floor, and likely damaging the concrete slab /shield / cookie and link to the pool

Bang 3: Its the second explosion the vertical component.


Missing all the ins and out, the implosion or sucking in that happened after bang 1

 

[Rive]

nope it is definitively the reactor 3 as subtitle on the original page
http://www.newcs.futaba.fukushima.jp/05-20000519/index41.html

The whole gallery has a 'reactor 3 ' subtitle, not the drawing. And there is that ABWR modell which does not fits with MK1 or MK2 containments at all. And the containment part of the drawing is square shaped, with the core at the centre. The Unit3 has the RPV on the side closest to the turbines.

I don't KNOW, but I seriously doubt that this is about Unit 3.

http://translate.google.hu/translat....futaba.fukushima.jp/05-20000519/index41.html

 

[|Fred]

Thank you rowmag ! It's great to have some one reading Kanji around here.
Mice is correct! This is the mighty Bolt Driver Machine.

 

[Jorge Stolfi]

The object is heavy -- yes, hard -- no. Isn't the flat roofing structure of most commercial roofs is something like corrugated metal with a thick layer of tar and pea gravel sprayed onto the metal substrate to form a heavy, watertight roof slab? Someone here must know commercial roofing, but I am betting the roof was fairly flexible, but heavy. And if the mass of the whole roof were lifted, peeled upwards largely intact and put in motion by a pressure wave from the explosion and then gravity, then that slab of roofing would have plenty enough mass and kinetic energy to do some serious damage IMO.

On the hi-res pictures one can clearly see the upper edge of the object. It is fairly smooth, with no signs of rebar. The object is also too thin for a concrete layer, but too thick for corrugated metal. It also seems quite stiff, bending rather than cracking. It was obviously hard enough to knife through the steel beams of the roof without any visible crack.

Indeed the roof seems to have been constructed as you described, but the metal layer was apparently made of many separate strips, perhaps 8--10 m long and 1 m wide, which are scattered all over the place.

Units #3 and #4 were twiins, apparently. If the object came from #4's roof, where is the corresponding object from #3?

Unit #1 had a different construction. There the explosion obviously pried the roof as a unit --- truss, metal base, and tarmac --- from the side walls. (in units #3 and #4, the roof truss was solidly anchored to the concrete walls, and the attachment resisted the much stronger explosions.) The roof of #1 may have been lifted for a short distance, then crashed back onto the floor below. Even this relatively gentle event turned the tarmac layer into rubble, and molded the roof to the shape of the underlying machinery. Thus the metal layer on #1 (if there was one) cannot have been very thick either.

if the object came from #4's roof, perhaps it was a partial armor plate, spanning only the middle part of the building, meant to protect the reactor against terrorist attacks?

 

[Rive]

Oyster Creek Blueprints

...

One can access these PDFs and the other parts of the FSAR at the NRC's Web-based ADAMS search page as follows:

1. Go to the main ADAMS site at http://wba.nrc.gov:8080/ves/
2. Select the Advanced Search tab
3. In the search box put "Accession_Number:ML011270* $titleyster" without the quotes
4. Press the Search button and wait

Thank you for this: it's very useful.

Oyster Creek is BWR2/MK1 as the Unit 1. Unit 2 to 4 are BWR3/MK1 as like Dresden NPP, Monticello, Quad Cities, Santa María de Garoña or Pilgrim NPP.
http://en.wikipedia.org/wiki/List_of_boiling_water_reactors

I've actually started to search, but it's too much, it'll be slow (days).

 

[Jorge Stolfi]

Another beautiful theory slain by ugly facts.

Well, OK, I will shut up. For now.

 

[clif]

REF 4177;


I don't KNOW, but I seriously doubt that this is about Unit 3.

According to the top of the page the entire photo section is about;

このレポートは、東京電力株式会社、福島第一原子力発電所、広報部の取材協力を受けております。 This report, Tokyo Electric Power Company, Fukushima Daiichi Nuclear Power Station, we received the cooperation of the public relations coverage.

and

2000.5.19 tour interview at the Fukushima Daiichi Nuclear Power Station Toukyoudenryoku

according to the webpage it is Fukushima #3

 

[|Fred]

where the floor control rooms gone ? supose to be in the south west corner but the remains do not seems to fit the structure

 

[MiceAndMen]

Thank you for this: it's very useful.

Oyster Creek is BWR2/MK1 as the Unit 1. Unit 2 to 4 are BWR3/MK1 as like Dresden NPP, Monticello, Quad Cities, Santa María de Garoña or Pilgrim NPP.
http://en.wikipedia.org/wiki/List_of_boiling_water_reactors

I've actually started to search, but it's too much, it'll be slow (days).

It does take a long time to search and you need some luck also. Many older documents have not been scanned into PDF format yet, and all you get for results are small 320-byte references to physical document numbers. I don't have the time or inclination to actually go in person to the NRC's reading room to look at physical documents or worse (microfiche), but if I did there are a few plants' drawings I would like to have a look at. You listed a few. Vermont Yankee and Millstone I are another two that I think are close to the Fukushima Daiichi designs.

There is a search option that's not listed there for minimum document file size that I worked out through trial and error (I think it's called $size:xxx) but it times out on most searches I tried. An option for "only downloadable PDF documents" would be very handy, but alas, it does not exist. Additionally, you are supposed to be able to check the boxes for several files on the left and download a .zip file that contains your selections. That doesn't work either; you have to download each one individually. It's got some bugs and quirky behavior, but overall I think they did a good job with the web-ADAMS search site. I'd rate it a solid 8 out of 10.

I suspect someone needed the Oyster Creek drawings in PDF form for some task in recent years and that's why they are available online.

 

[NUCENG]

Stacking in a SFP?

ＭＯＸ燃料を真上から (Fuel from right above)

MOX would mean reactor #3

The objects on the right appear to be a level higher then those on the left.

Image from here

http://www.newcs.futaba.fukushima.jp/05-20000519/index41.html"

What that appears to be to me is two fuel racks to the right and left at the same level, but empty. In the center are two short sections consisting of two rows filled with control rods. The lifting handles of fuel bundles and control blades are different and these look like control blades to me.