Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[jensjakob]

AntonL, I think youre wrong. Servicetunnel goes towards the Northwest.

Reactor 1 is at the North?

And landside is on the West?

Then Servicetunnel goes to the Northwest?

 

[TCups]

TCups, SFP has been stated to be in SE corner of building, At fukushima reactor 1 is north of reactor 4, you have North South interchanged

(By the way you can image link and attachment) as I have done here by clicking on the thumb twice)
https://www.physicsforums.com/attachment.php?attachmentid=33373&d=1300788049

https://www.physicsforums.com/attachment.php?attachmentid=33373&d=1300788049

Yes (darn it) and I didn't catch it immediately. I re-uploaded a correct annotation. I think the diagram matches the text now. SFP is at the SOUTHEAST corner of Bldg 3 as best I can tell.

I MUST be off to work. Will read all replies later.

 

[AntonL]

AntonL, I think youre wrong. Servicetunnel goes towards the Northwest.

Reactor 1 is at the North?

And landside is on the West?

Then Servicetunnel goes to the Northwest?

jensjakob, I do think the IAEA will have it correct http://www.slideshare.net/iaea/aerial-schematic-view-of-fukishima-daiichi-19-march-2011" top left hand corner of slide 1

 

[TCups]

jensjakob, I do think the IAEA will have it correct http://www.slideshare.net/iaea/aerial-schematic-view-of-fukishima-daiichi-19-march-2011" top left hand corner of slide 1

Yes, apologies again. My typing fingers didn't keep up with my mind. Unit 3 is north of Unit 4. Unit 3's SFP is on the southeast corner of the building, more or less, but the buildings do not set on a true North-South-East-West axis as my diagram would seem to suggest. Obviously the ocean side is to the east. None the less, the "anatomy" of the building with respect to the location of the shaft, SFP, and core containment and therefore, the logic of the blast coming through the SFP, NOT the equipment pool holds up, which is the point I was, in my imperfect way, trying to make here.

 

[jensjakob]

The picture is rotated.

I google mapped it. Please review the orientation.

http://maps.google.dk/maps?f=q&sour...157&t=h&z=16&iwloc=A&cid=17060867344567820820

 

[dgdd]

Quoting http://www.nytimes.com/2011/03/22/world/asia/22nuclear.html:

In 2000, a whistle-blower at a separate company that was contracted
to inspect the reactors told regulators about
cracks in the stainless steel shrouds that cover reactor
cores at Fukushima?s Daiichi plant.
But regulators simply told the company to look into the issue,
allowing the reactors to keep operating.
[...] He said the prefecture itself
and the communities hosting the nuclear plants did not learn about the
cracks until regulators publicized them
in 2002, more than two years after the whistle-blower reported the cracks. [...] whistle-blowers gave
information to Fukushima Prefecture showing
that the company had falsified inspection records and hid flaws over
16 years to save on repair costs.

 

[TCups]

The picture is rotated.

I google mapped it. Please review the orientation.

http://maps.google.dk/maps?f=q&sour...157&t=h&z=16&iwloc=A&cid=17060867344567820820

REGARDING THE DAMAGE AND MECHANISM OF DAMAGE TO UNIT 3

How unfortunate that my error on the N-S label (now corrected) or whether or not the buildings are in a true N-S-E-W orientation or somewhat askew misdirects the discussion. In general, the MAJOR POINT is that it is the corner nearest the SE of Building 3 where the SFP is located.

If one assumes that the long-distance video of the explosion was taken from high ground to the west, instead of out to sea, to the east, then the initial explosion was directed to the right, or generally to the south and toward Bldg 4, then it is the south wall of Bldg 3 that is blown out by the initial explosion and the north wall of Bldg 3 that is destroyed by the overhead crane.

If we agree on those points, then the pictures of the damage I see seem to make sense and reinforce the sequence of events I suggested and outlined earlier:

1) the hydrogen & oxygen from hydrolysis of hot steam in the presence of zirconium comes from the core of the reactor, and indicates at least some damage to the core.

2) the hydrogen accumulated in the primary (dry wall) containment and at relatively low pressure, could escape from the drywell cap.

3) the force of the earthquake alone could have sloshed out significant amounts of water from the SFP, irrespective of boiling, evaporation, or loss of circulation pumps

4) there is a transfer chute and a mechanical gate mechanism connecting the drywall containment to the SFP used to transfer fuel rods, underwater, from the core to the SFP.

5) the pneumatic seals on the gate are inflatable and would be compromised by a prolonged loss of power.

6) a lower water level in the SFP, and thus, loss of hydrostatic pressure behind the gate (outside of the primary, drywall containment) would further compromise the strength and integrity of the gate if a blast occurred from within the drywall containment

7) If the force of a blast exiting the primary containment were directed sideways, through that gate and the transfer chute, then the reinforced floor and walls of the SFP would function as an acoustic lens, directing much of the force of the blast (and perhaps a large, expanding volume of steam from the vaporized water which remained in the lower portion of the SFP) upward.

8) there may or may not have been a secondary explosion of hydrogen leaked into the upper portion of Bldg 3. (A primary explosion of that sort, external to the containment in the upper portion of the building, probably occurred in Bldg 1).

9) the blast blew portions of the south wall of Bldg 3 into Bldg 4's north wall. "Shrapnel" from the Bldg 3 blast may have initially damaged Bldg 4 leading to the fire(s) that occurred in Bldg 4 thereafter. (questionable, not confirmed by satellite photos. See Anton's later post, #820)

10) Blast damage from Bldg 3 can also be clearly seen involving the roof of the steam turbine buildings to the east and to at least one of the additional buildings to the west. A large portion of the crane fell, damaging the adjoining building structure below, to the north.

11) It is not possible to tell with certainty if the drywell containment plug atop Reactor 3 has been blown skyward. Perhaps not, the evidence being lack of conclusive damage to the roof girder structure directly over the apparent location of the plug, but instead, primarily over the SFP.

12) If there are fuel rods in the photos of the damage and debris atop Bldg 3's east side, then it appears more likely to me that they came from the SFP of 3, not the reactor core. Certainly any remaining water in the SFP would act to transfer the force of the blast (shock wave) more efficiently into the submerged portion of the pool and the rods therein, and the floor of the pool would reflect that shock wave, water, steam, and maybe spent fuel rod assemblies skyward.

13) Steam appeared to be venting, in a jet, into the region of the damaged SFP of Unit 3 after the blast (the helicopter flies through this cloud of steam). The pressure in the primary containment of Unit 3 has dropped. Radioactivity levels especially around unit 3 have risen. Black smoke was later seen rising from the same region.

14) It is very likely that the primary drywall containment of Unit 3 and not unlikely that the Unit 3 reactor vessel or pipes or valves connected to the RV have been damaged, initially venting steam, then, perhaps something else burning within the RV.

15) from the available photos, such as they are, I cannot confirm that there are fuel rod assemblies or water remaining in the SFP of unit 3.

Comments or corrections?

 

[jensjakob]

TCups - quite plausible I would say.

 

[TCups]

FORCE OF EXPLOSION AT UNIT 3?

Does anyone have a source for seismographic recordings at the time of the explosion at Unit 3? If so, it may be an objective way to assess the size of the explosion relative to, perhaps, the explosion at Unit 1.

 

[artax]

just found some more video:

 

[AntonL]

9) the blast blew portions of the south wall of Bldg 3 into Bldg 4's north wall. "Shrapnel" from the Bldg 3 blast may have initially damaged Bldg 4 leading to the fire(s) that occurred in Bldg 4 thereafter.
Comments or corrections?

First: regarding 9 - Reactor 4 looks in a pretty good shape to me after explosion of reactor 3

 

[AntonL]

Blast mechanism at fukushima

BLAST MECHANISM AT FUKUSHIMA

Observed are three catastrophic explosions Unit 1, 3 and 4 with pretty much the same
consequence and Unit 2 had a small Hydrogen explosion that was contained with little
damage and thus I propose that the cause of the Hydrogen Blast is not from Hydrogen
produced in the reactor and somehow leaked from the containment vessel into the building, but
instead all three buildings where destroyed by hydrogen produced in the spent fuel pools
This would then be a common cause of failure and most likely.

Why the SPF water level went low, certainly wave action initiated by the earthquake are a
cause, the Earth shook for minutes instead of seconds, I believe 5 minutes, Kobe earthquake
was 15 seconds. Other reasons like leakage or borrowing water for cooling reactor to avoid
meltdown, we can speculate.

 

[TCups]

First: regarding 10 - Reactor 4 looks in a pretty good shape to me after explosion of reactor 3

Yes it does. OK, thanks Anton. What to you think about the possibility of shrapnel damage that might not be obvious as the etiology of the fire at Unit 4?

Refresh my memory -- only one major explosion at Unit 3, and as far as I remember, no major explosion that I can immediately recall reported at Unit 4, right?

Is it possible that the shock wave could have done internal damage to the inside of Unit 4 or to the structural integrity of Unit 4 that might not be immediately visible in the satellite photo? Certainly the roof isn't peeled back as it appears to be in later photos.

Maybe there was distortion or spherical aberration from the camera lens shooting through the helicopter window that makes one of the structural columns at the NE corner of Unit 4 look slightly bucked inward. Hmmm. . .

All of my fly over image frames are on the home computer and I am at work. More to study this evening.

Suggestions?

 

[TCups]

BLAST MECHANISM AT FUKUSHIMA

Observed are three catastrophic explosions Unit 1, 3 and 4 with pretty much the same
consequence and thus I propose that the cause of the Hydrogen Blast is not from Hydrogen
produced in the reactor and somehow leaked from the containment vessel into the building, but
instead all three buildings where destroyed by hydrogen produced in the spent fuel pools
This would then be a common cause of failure and most likely.

Why the SPF water level went low, certainly wave action initiated by the earthquake are a
cause, the Earth shook for minutes instead of seconds, I believe 5 minutes, Kobe earthquake
was 15 seconds. Other reasons like leakage or borrowing water for cooling reactor to avoid
meltdown, we can speculate.

IMO, the overall force demonstrable from collateral damage, and vertical component of the blast at Unit 3, demonstrable from the videos of same, are, I contend, much stronger and much different from any at Units 1 and 4. Do you agree?

Is there any video of a catastrophic blast at Unit 4? If so, I have overlooked it and need to review it. Thanks.

 

[AntonL]

IMO, the overall force demonstrable from collateral damage, and vertical component of the blast at Unit 3, demonstrable from the videos of same, are, I contend, much stronger and much different from any at Units 1 and 4. Do you agree?

Is there any video of a catastrophic blast at Unit 4? If so, I have overlooked it and need to review it. Thanks.

I agree Unit 3 has spectacular column of dust rising, Unit 1 also has a similar vertical
component but without dust, Unit 1 has a steel upper structure with bolted on steel panels,
Unit 3 has a concrete upper structure with concrete panels, these are stronger so the roof
gave first in Unit 3 instead of the side panels as in Unit 1

I have not seen any video of 4 exploding. All 4 reactors are reported to have had hydrogen
blast with various force and damage. The force is equivalent to the amount of hydrogen
accumulated. If the SFP are boiling the air O2 would have been displaced by the steam and
furthermore would have been sucked up by the zirconium first before it extracted the oxygen
from the H20, Thus the atmosphere in the empty pool would be H20 and H2, only separating
outside the pool and fate determined how much H2 would accumulate in the building before
the bang.

Here is a time line of the explosions.
Unit 1 - 12.03.2011 at 15:36
Unit 3 - 14.03.2011 at 11:01
Unit 4 - 15.03.2011 at 06:14
Unit 2 - 15.03.2011 at 06:20

In all the reactors 1 to 3 the containment vessels where vented after reactor venting.

 

[curious11]

just found some more video:

Have we not seen this vid already.
In any case, there are some interesting features :

At 1:14 we can possibly see the green crane over the SFP?

What is this feature? It looks like the top of a whiskey distillery. Note the round opening at the top.

Any idea what the brown/orange stuff is ?

 

[artax]

Yes but they've been pulled from you tube so thought I would re-post! your obs. are interesting, that whisky thing could be the top of reactor vessel, and yes... no idea what the brown stuff is but don't know what those pipes were carrying before, steam probably as they run to the chimney stacks. there's a lot of info in these vids so I'm surprised no 'experts' have analysed them.

THERMAL IMAGE OF REACTORS for those interested there's a discussion on housepricecrashforum, where one poster has posted this recent thermal image:
http://www.zerohedge.com/sites/default/files/images/user5/imageroot/bernanke/heatAll.jpg

This is a very interesting science/engineering problem and the lack of information is just so frustrating.

 

[curious11]

Yes but they've been pulled from you tube so thought I would re-post! your obs. are interesting, there's a lot of info in these vids so I'm surprised no 'experts' have analysed them.

Of course! Sorry if I sounded out of turn!

 

[TCups]

I agree Unit 3 has spectacular column of dust rising, Unit 1 also has a similar vertical
component but without dust, Unit 1 has a steel upper structure with bolted on steel panels,
Unit 3 has a concrete upper structure with concrete panels, these are stronger so the roof
gave first in Unit 4 instead of the side panels as in Unit 3

?
I can't quite understand what you are saying.

Unit 1 has a (weaker) steel upper structure with bolted on steel panels (OK)
Unit 3 has a concrete upper structure with concrete panels, these are stronger (than Unit 1?)
The roof (of Unit 4?) gave first
The side panels of Unit 3 gave first (because?)

Can you clarify, I don't think I follow completely. Thanks.

 

[AntonL]

?
I can't quite understand what you are saying.

Unit 1 has a (weaker) steel upper structure with bolted on steel panels (OK)
Unit 3 has a concrete upper structure with concrete panels, these are stronger (than Unit 1?)
The roof (of Unit 4?) gave first
The side panels of Unit 3 gave first (because?)

Can you clarify, I don't think I follow completely. Thanks.

TCups like your North South
Unit 3 has a concrete upper structure with concrete panels, these are stronger (than Unit 1)
The roof (of Unit 3) gave first as concrete structure side panels are stronger putting more force on the roof.
The side panels of Unit 1 gave first (because?) as seen in video.

I have edited original post accordingly

 

[M. Bachmeier]

BLAST MECHANISM AT FUKUSHIMA
Why the SPF water level went low, certainly wave action initiated by the earthquake are a cause, the Earth shook for minutes instead of seconds, I believe 5 minutes, Kobe earthquake was 15 seconds. Other reasons like leakage or borrowing water for cooling reactor to avoid
meltdown, we can speculate.

Consider again the effects of the initial earthquake:

(1) Report from worker inside #4 at the time of the earthquake describing equipment (likely heavy) brought in for inspection toppling over (large potential for damage to key systems).

(2) The tectonic plate under the area dropped, now leaving several coastal areas subject to flooding due to high tide. Take a rectangular container of water (full near to the top) and drop it 5 cm to a hard flat surface and see how much water is lost. Now grab hold of that same container and shove it 5cm to the side and measure how much additional water is lost.

(3) What was the height (above sea level) of the plant before and after the earthquake?

(4) How far to the east did the entire land mass shift?

Obviously (4) is an oversimplification, but one could get an idea of how much energy was transferred into wave motion in the SFP. The energy was transferred over approx. 5 min. so there's no way to be sure if the wave amplitude of successive motions were more additive or had the effect of canceling out, but since the local effect was to drop down and move toward the east it would not be unreasonable to expect significant water loss (in all SFP's) and that kind of wave motion could damage the transfer gates regardless of power loss and seal failure. Add to that a loss of circulation (cooling system) and the rate of evaporation increasing with temperature rise and you don't need any other explanation for reactor #4's SFP.

 

[Reno Deano]

Busy minds and good speculation. Would like to know just what vent path was used by the operators to vent the reactor and primary containment (PC)? The space between the shield plugs anbd the PC Dome Cap (Steel) probably would not contain enough hydrogen to blow the shield plugs off, but just displace them and open another vent path.

Just some idle thoughts.

 

[TCups]

Not a nuclear engineer here, and maybe I have some fundamental misunderstanding that needs to be corrected, but . . .

What the heck is the whole "torus" design and function about if not for containment of pressure vented from the reactor vessel?

If there is a pressure containment function implied by the torus design, under normal circumstances, why wouldn't the RV be vented into the primary containment and torus?

If there were some unusual or emergent circumstance, why might the RV be vented elsewhere (ie to the outside of the primary containment?)

If hot hydrogen gas, under pressure, were accumulating in the torus and drywall containment, wouldn't it tend to rise, accumulate under the drywell cap, potentially leak from under the drywell cap and then spontaneously vent externally?

If the accumulated hydrogen within the drywell and torus containment were to ignite and explode, wouldn't the exit path of the explosion "vent" through this same pathway?

I am obviously somewhat confused here.

 

[artax]

someone's removed the shake from some of the vids but the bit I'm interested in isn't there!
http://www.youtube.com/user/KurtsFilmeVideo#p/u

 

[AntonL]

Here is a time line of the explosions and reported CV venting
Unit 1 - 12.03.2011 at 15:36 : CVv 15:00 on 12.03.11
Unit 3 - 14.03.2011 at 11:01 : CVv 09:20 on 13.03.11
Unit 4 - 15.03.2011 at 06:14
Unit 2 - 15.03.2011 at 06:20 : CVv 11:55 on 13.03.11

There is a correlation between Unit 1 CV venting and Hydrogen blast.

Below SFP data FU = fuel units followed by pool volume and heat load of the FU
Unit 1 - 292 FU 1200m3 60kW
Unit 2 - 587 FU 1425m3 400kW
Unit 3 - 514 FU 1425m3 200kW
Unit 4 - 1331 FU 1425m3 2000kW + 200 brand new FU (yes 2MW not a typo)

This sets a new light on my earlier proposal
Unit 1 exploded due to H2 leak of venting system - possibly Earth quake damage
Unit 2 to 4 exploded due to hydrogen generation from equipment pools.

 

[Reno Deano]

The Torus is design for steam water suppression during a LOCA. Venting of gas from the Dry Well and RPV is via other systems.

See: http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf"

 

[romillyh]

Re M Bachmeier comments in Post 830:

For anyone who's in any doubt about what a strong ground wave looks like, how fast it travels, and what it can do to objects of any weight, it's worth looking at a rather grisly video of an underground H-bomb test for Project Cannikin in Amchitka, Alaska. Blast was magnitude 7.0 on Richter scale. Detonation was 2 km below surface. Video is just 0:47 long.



Imagine this going on for 5 mins! Are the Fukushima plants "anchored" directly to the ground/rock (i.e. they take the full force of the bucking), or do they have some kind of disconnect to absorb strong ground movements, as one understands quake-"proofed" buildings in Japan do?

Re 5 mins: From memory, seismic trace of the main M9 quake as recorded by the British Geol Survey in Edinburgh can actually be seen continuing for around 50 minutes, though this was recorded the other side of the planet (echoes, reverbs?) and the after-events obviously tail off in magnitude after the main shock.

 

[romillyh]

And sorry, I should add to that last message (836) that I saw somewhere that the force of the quake at Fukushima -- what actually hit it, as opposed to the magnitude 9 over the epicenter -- was around M7.

 

[donvance]

I bought my Iodide tablets for me and my family! Being prepared is important! Do not be fooled by the Iodate tablets, Iodide is the way to go! They are good for a 14 day protection!
Get some everyone and be prepared, or just spend 1000's and build yourself a fallout shelter?

 

[AntonL]

Not a nuclear engineer here, and maybe I have some fundamental misunderstanding that needs to be corrected, but . . .

What the heck is the whole "torus" design and function about if not for containment of pressure vented from the reactor vessel?

If there is a pressure containment function implied by the torus design, under normal circumstances, why wouldn't the RV be vented into the primary containment and torus?
[/PLAIN]

Under 'normal' circumstance steam is vented from RV into the torus and bubbled through the hopefully cool water so condensation can take place and CV pressure should not rise only the torus water level would rise.

Under 'meltdown' condition steam and H2 is vented from RV into the torus. If CV pressure rises CV contains steam and compressed H2 and N2 - no O2.

Torus is part of the primary containment and in later models no longer used as in the Mark 3 reactor
Fukushima Daiichi Units 1 to 5 are Mark 1 and Unit 6 is a Mark 3
[PLAIN]http://www.atom-fukushima.or.jp/qa/qa-164/img/qa-1.gif

When a melt-down takes place you want no water near it otherwise you will have a steam explosion.
The torus, in mark 1, and meltdown containment in mark 3 keep the water well away from the hot meltdown

 

[Borek]

I bought my Iodide tablets for me and my family! Being prepared is important! Do not be fooled by the Iodate tablets, Iodide is the way to go! They are good for a 14 day protection!
Get some everyone and be prepared, or just spend 1000's and build yourself a fallout shelter?

Taking them without a reason is dangerous for your health. I guess someone made a perfect deal selling you something you don't need.

 

[Reno Deano]

I bought my Iodide tablets for me and my family! Being prepared is important! Do not be fooled by the Iodate tablets, Iodide is the way to go! They are good for a 14 day protection!
Get some everyone and be prepared, or just spend 1000's and build yourself a fallout shelter?

Iodine levels at 100 times background is not dangerous at all. BTW, I assume your doctor told you about the possible serious side affects of taking KI? Can you imagine being in a underground shelter during a 9 magnitude earthqake?

The off site contamination is being blown way out of proportion. They should be discussing the actual relative low risks of eating foods with only slightly higher than background radionuclide contamination. Tens of thousand of nuclear works and bomb testing fallout survivors that received thousands of times hight doses, did not suffer any serious consequence over their exposures. Very low concentrations of long live primordial Uranium is present in most of our water and food stuffs anyway.

 

[TCups]

Under 'normal' circumstance steam is vented from RV into the torus and bubbled through the hopefully cool water so condensation can take place and CV pressure should not rise.

Under 'meltdown' condition steam and H2 is vented from RV into the torus. If CV pressure rises CV contains steam and compressed H2 and N2 - no O2.

Torus is part of the primary containment

OK, so . . .

1) In unit 4, it is beyond dispute -- if the explosion was a hydrogen explosion, then the hydrogen came from spent (and possibly un-spent) fuel rods in the SFP, not in the empty RV.

2) In units 1, 2, 3, if hydrogen exploded, it would need oxygen and therefor, the source of the explosion was not within the RV

3) In units 1, 2, 3, hydrogen could have been and was likely to have been produced by both an overheating reactor core in the RV and by overheated fuel rods in the SFP.

4) With loss of cooling, the hot cores in the reactor were, IMO, the more likely first source of trouble and first source of hydrogen production (correct?)

5) If a RV's steam and hydrogen were vented into the drywell torus, bubbling through the suppression pool of cool water, would the hydrogen then be in an atmosphere of air or of nitrogen, flooding the torus?

6) Is it possible for hydrogen (or hydrogen and oxygen) to have accumulated in the upper portion of the drywell containment, near the drywell cap, under pressure (for example if the normal venting system -- ducts, pipes -- had been damaged?

7) Except for Unit 4, why IYO, is the source of exploding hydrogen more likely from the SFP than, somehow, from the RV via leakage into the primary containment?

8) Is it not possible or even likely, that whichever came first, if an explosion occurred in Unit three, then both accumulated hydrogen in the upper building, external to the primary containment, and hydrogen leaking from under the drywell cap, would have ignited and led to explosions both inside the drywell containment and inside the upper building structure?

9) Why do you think the SFPs were the primary source of all explosions?

 

[M. Bachmeier]

I bought my Iodide tablets for me and my family! Being prepared is important! Do not be fooled by the Iodate tablets, Iodide is the way to go! They are good for a 14 day protection!
Get some everyone and be prepared, or just spend 1000's and build yourself a fallout shelter?

Yes, I think it's a 'miracle' that there haven't been more attempts to advance questionable remedies, concoctions, 'medicines' and alike associated with fears of radiation. What do you think??

Sorry for being off topic... I just couldn't help myself.

 

[AntonL]

9) Why do you think the SFPs were the primary source of all explosions?

By demonstration of Unit 4