Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[rmattila]

Wouldn't it also happen in BWR cores then? Boiling water, high radiation would generate lot of hydrogen, which would not recombine (boiling + steam environment). This means cores would generate a lot of hydrogen, a lot more than observed, don't you think?

If you mean BWR plants under normal operation, they do have recombiners in the condenser vacuum/off gas system in order to recombine the hydrogen and oxygen back to water prior to transferring the gases to the actual off-gas treatment.

 

[SteveElbows]

Just for the sake of completeness I'll say that what is actually seen within the blue circle on this picture, is quite likely a device that has received attention on this thread many times before, because it can be seen from a few different angles and early on some people may have confused it with the missing refuelling bridge.

http://www.houseoffoust.com/fukushima/tour/R3_equipment.jpg

Possibly some people have been calling this 'the spanner' of late, but I prefer to use its real name. I had not realized that the house of faust website had already named it, and wasted an hour of my time finding out what it was called independently, doh.

Its a stud tensioner. Or at least we think it is. There is some chance that there is at least one other large, circular piece of equipment that may have a different function and lives on the service floor of the reactor, or what I've seen may simply be an alternative version of a stud tensioner, as the ones I've seen on the net come in a variety of looks. If I find a decent image of what I'm on about I will post it.

http://www.siempelkamp-tensioning.c...ure-vessels-rpv/what-is-a-stud-tensioner.html

 

[GJBRKS]

You're referencing information from a ufo-magiccrystals-NWO-aliens conspiracy site. There may be some useful info posted there but I wouldn't trust the dialogue.

I'm aware of the reputation , but I liked the graphic enough to illustrate the idea.

Most counterarguments so far have been circumstantial :

- ' People would have died'
- ' It's not because we said so'
- 'The presented evidence doesn't fit'
- ' Something else would have broken'

But none of these are saying that it would have been impossible a priori ...

And considering the force and direction of the destruction I'm still not convinced that it wasn't the vessel itself that ruptured , perhaps by fuel entering the torus and starting a steam explosion , exiting back through the torus upwards into the drywell and reactor.
That's not to say that I do not value your counterarguments , I see more reason there than in this of mine ...

So thanks for your ideas , I'll go back to studying now ...

 

[GJBRKS]

Just for the sake of completeness I'll say that what is actually seen within the blue circle on this picture, is quite likely a device that has received attention on this thread many times before, because it can be seen from a few different angles and early on some people may have confused it with the missing refuelling bridge.

http://www.houseoffoust.com/fukushima/tour/R3_equipment.jpg

Possibly some people have been calling this 'the spanner' of late, but I prefer to use its real name. I had not realized that the house of faust website had already named it, and wasted an hour of my time finding out what it was called independently, doh.

Its a stud tensioner.

http://www.siempelkamp-tensioning.c...ure-vessels-rpv/what-is-a-stud-tensioner.html

That must be it

 

[LabratSR]

New(to me at least) set of ground level pictures posted at Cryptome. http://cryptome.org/nppw-series.htm

 

[jim hardy]

Re: Japan Earthquake: nuclear plants

--------
Would this qualify as a crude nuclear reactor (with steam as neutron reflector/moderator):


{Jorge i liked your sketch here but coldn't copy it, I'm a computer nebbish.}

""""EDIT+: Imagine that the water is boiling vigorously, so the steam is heating up as it flows along the hot fuel tubes; but leaves the racks when it is still well below 800 C, so the assembly heads (where no heat is being generated) remain relatively cool and undamaged. """


Jorge i like your thinking. I am not enough of a reactor physics guy to answer your question.

My personal belief is the molecules in steam at any reasonable pressure are just too far apart to make a decent moderator. Imagine yourself micoscopic and tagging along with the neutrons - water is a crowded street at rush hour of molecules but steam is an empty arena - what, a few thousand times less dense? So the neutrons don't get slowed down very well and wander away while they're still too fast to fission.
62.4 lbs cubic foot for water versus maybe 1/40th lb for steam is a ratio of maybe 2500 to 1 ? Hydrogen is a better moderator but still the atoms are far apart.
So my intuitive answer is i don't thinkk the pool went critical, but what you have suggested is logically correct. If something burped a big slug of water up into the dried out fuel maybe it'd do it, but to my thiniking a H2 blast should push water down.

My self i think Arnie is not on right track, but i could be wrong.

Take a look at 2:06 in that #3 pool video, Do i see rebar blown into pool and concrete rubble on top of prettty complacent fuel elements? Like a wall blown into pool?

and at 2:12 are we looking back through a hole in a pool wall? Maybe somebody will sharpen up that video.

apply your same logic to reactor.

 

[MiceAndMen]

Interresting is that the radiation in the SFP should come from the reactor core of unit 3 and not from the fuel in the pool.

How is it possible that the explosion at unit 3 could "extract" fuel from the core to the pool?

http://www3.nhk.or.jp/daily/english/10_30.html"

That news item is absurd. Talk about comedy gold...

None of these substances were detected during an inspection on March 2nd, before the accident triggered by the March 11th disaster.

As a great American once said,

Well surprise surprise surprise!

 

[MiceAndMen]

I'm aware of the reputation , but I liked the graphic enough to illustrate the idea.

Most counterarguments so far have been circumstantial :

- ' People would have died'
- ' It's not because we said so'
- 'The presented evidence doesn't fit'
- ' Something else would have broken'

But none of these are saying that it would have been impossible a priori ...

And considering the force and direction of the destruction I'm still not convinced that it wasn't the vessel itself that ruptured , perhaps by fuel entering the torus and starting a steam explosion , exiting back through the torus upwards into the drywell and reactor.
That's not to say that I do not value your counterarguments , I see more reason there than in this of mine ...

So thanks for your ideas , I'll go back to studying now ...

If you're going to dismiss the fact that a blown RPV cap would send radiation measurements off the charts, then there's not much that will convince you.

As for fuel entering the torus, there is no direct way for it to get there. The torus blowdown design is meant to accommodate gas, and any falling fuel would have to follow a path that just doesn't seem physically possible. A particle of solid matter cannot get into the torus by falling straight down from any point under the RPV.

 

[jim hardy]

i've been trying to follow the posts so excuse me if i missed discussion of this one, linked yestarday i think.

http://i.imgur.com/IqCPH.jpg

wold imbed picture if knew how.

Anybody know source of the photo? Is it credible?

Can you photo capable guys offer an opinion on the snaggletooth round looking shape in the red rectangle connected by red line to reactor vessel head? It's way down in the shadows.

I don't trust photographs since ever since Jurassic Park, but were i trying to mimic a vessel with head blown off that's what i would photoshop in.
The bolts will break in their thinned center section and stick up just as in that shadowy form. The bolts are thinned in center because that's where you want them to stretch wnen tensioned. So if the head lifted from overpressure and went someplace else it'd look like that.

Myself i'd expect the bolts to just stretch and the head to set back down after pressure relieves, but I'm no mechanical engineer.

The steam separators above the core would act as an upside down collander and strain out the big chunks of reactor, so the explosion looks to me consistent with steam explosion in vessel and ejection of water and small pieces of debris.
Remember steam shuts these reactors down, but gooses the throttle on Chernobyl type cores.

So a modest neutron boosted steam explosion could be plausible. the $64 question is "What does the head look like" - is it fine or are its bolts stretched?
You'd think there'd be a photo floating around.

.

is there a photodoc in the house?

 

[SteveElbows]

Can we bring the reactor 3 talk down to earth?

Specifically, since the talk of a crack in containment appears to have been confirmed in an IAEA presentation some days back, are we entirely sure that these people have seen images we havent?

Specifically, there was that Japanese defence force video taken in March, and one area where stuff was billowing out always caught my eye. I was not on this forum back then and although I did wade through many of the early pages, I do not recall whether this avenue of enquiry was picked up on at the time.

Im talking about the attached image, which as best I can tell from watching the video several times, shows stuff emerging from the area where containment could be said to begin. I am pretty sure we are looking at the steam dryer separator storage pool, and the area where the large concrete 'gate' is located which connects it to the upper part of reactor containment. Could this count as the crack that has been described, is it reasonable evidence of containment damage, or am I barking up the wrong tree?

Its taken from this video, where this scene shows up briefly at around 3 mins 8 seconds, and again at approx 3 mins 23 seconds.

http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

 

[MiceAndMen]

i've been trying to follow the posts so excuse me if i missed discussion of this one, linked yestarday i think.

http://i.imgur.com/IqCPH.jpg

wold imbed picture if knew how.

Anybody know source of the photo? Is it credible?

Please go back just 1 page and look at post 6454 and what follows. The reactor pressure vessel head did not blow off. That idea was debunked back in March.

 

[jim hardy]

okay thanks, i didnt find you folks till April. Will go back further.

 

[jpquantin]

If you mean BWR plants under normal operation, they do have recombiners in the condenser vacuum/off gas system in order to recombine the hydrogen and oxygen back to water prior to transferring the gases to the actual off-gas treatment.

Haa, interesting. Do you have an indication of their capacity? By design how much would they process (depending on plant power I guess)?

Edit: and are there such recombiners over spent fuel pools?

 

[MiceAndMen]

Can we bring the reactor 3 talk down to earth?

Specifically, since the talk of a crack in containment appears to have been confirmed in an IAEA presentation some days back, are we entirely sure that these people have seen images we havent?

Where is that IAEA presentation, please? I must have missed it.

There are 2 pictures on this page http://cryptome.org/eyeball/daiichi-npp14/daiichi-photos14.htm that show Japanese SDF soldiers collecting "data and temperature" measurements on April 26 from a helicopter over the plant. Surely they were also taking conventional photographs. None of those have been released.

They almost certainly have imagery we have not seen.

 

[razzz]

Re: Japan Earthquake: nuclear plants

...My self i think Arnie is not on right track, but i could be wrong.

Take a look at 2:06 in that #3 pool video, Do i see rebar blown into pool and concrete rubble on top of prettty complacent fuel elements? Like a wall blown into pool?

and at 2:12 are we looking back through a hole in a pool wall? Maybe somebody will sharpen up that video.

apply your same logic to reactor.

What goes up must come down so I wouldn't get to excited about a pool full of debris as it is still holding water. I'd be more interested in the location and size of the crack in 3's containment vessel.

Edit: Searching for crack info might be tough as rumors claim references to it i.e. crack in a vessel, have been scrubbed. NY Times had an article mentioning it...maybe Google cache would still hold it but no specifics of size or location were reported at the time.

 

[SteveElbows]

Its taken from this video, where this scene shows up briefly at around 3 mins 8 seconds, and again at approx 3 mins 23 seconds.

http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

Also for the sake of adding the final bit of info I have left to add to conversations about round equipment and the layout of the reactor fuel service floor, I think the same video also shows the reactor cap of unit 4, has this been noticed before?

Watching the video from around the 2 mins 46 seconds mark to get bearings in relation to the yellow containment cap that we know very well already. Watch as the camera starts to show stuff that is further to the right of this yellow cap. Pause it around 3 mins 6 seconds. There is a bit of circular equipment visible at the top of the image, I believe this is still attached to the reactor cap after removal of the cap, and with that in mind a fairly faint image of a dark cap becomes apparent. They look like they are leaning noticeably, but I am wary of how much things can be misjudged due to angle image is being shot at, etc.

 

[SteveElbows]

Where is that IAEA presentation, please? I must have missed it.

Page 6 of this:

http://www.slideshare.net/iaea/technical-briefing-11-0505

In the containment integrity row and the observation column, the last point thing it says is:

'Images of Unit 3 show crack in the primary containment and steam released from the reactor building.'

The lack of detail is what has caused me to have room to wonder whether the images I just mentioned could be what they refer to, or whether I am looking at the right part of the building at all. For now I'd say the footage I refer to is a potential candidate, but I would welcome lots more opinion on this matter.

 

[Jorge Stolfi]

62.4 lbs cubic foot for water versus maybe 1/40th lb for steam is a ratio of maybe 2500 to 1 ?

Wikipedia gives that ratio for steam at ~250 C, 1 atm. Then the cross-section for neutrons in 1 cm layer of liquid water would be equivalent to 2500 cm = 25 meters of steam. Indeed it seems that the steam above and around the fuel racks will not be enough to function as moderator/reflector, would it?

On the other hand, the 'oscillating water level' hypothesis assumes that liquid water, not steam, is the moderator during the 'high tide' phase. Then, without the boral baffles, criticality would be quite possible, yes?

apply your same logic to reactor.

In a working reactor the fuel is supposed to be submerged and cool at all times. If cooling stops and the water level drops below the top of the fuel, oscillations in the level would be largely irrelevant since the chain reaction will be suppressed anyway by the control rods --- up to the melting point of steel (1500 C), at which point the zircalloy has probably been corroded and so the core collapses.

 

[clancy688]

The odds are pretty good that they have imagery we have not seen.

Well, we only get grainy, low-res-low-bitrate videos of the plant (T-Hawk vids, fuel pool vids, etc.). I can't believe that their technical gear is so old that it can't do better than those horrible images.

This winter I went skiing in the alps. One guy had a little helmet camera with him. It fit into a closed fist, was waterproof up to several meters and could film 1080p on a 16gb flash card. Price: Only 300 Euros or so...

TEPCO is (or at least ist trying to) running nuclear power plants. If they don't even have gear on par to stuff which's available for little money to the public, they are the biggest morons I've ever seen. And as stupid as they appear to be, they can't be that stupid.

So they probably encoded those videos to be grainy. They probably have 1080p versions. And if that's the case, it's not surprising at all for them to hold back some photos as well.
Last year, we had the Loveparade disaster in Germany - a mass stampede with 20 dead. Afterwards, the organizer released 720p video footage from every security cam in the area, it must've been 20 gigabytes overall.
And now we get grainy, low res .mpg vids from TEPCO... it's a shame.

 

[SteveElbows]

They almost certainly have imagery we have not seen.

I worded my point badly. I don't mean to suggest that nobody in authority has seen anything we havent, only that perhaps we shouldn't be quite as much in the dark about this issue of unit 3 primary containment crack as we think we are.

I remember some confusion about how different entities referred to different layers of containment early on, so I am even left slightly vague about what would count as primary containment. Does the concrete around the containment vessel count?

When people imagine pictures of a primary containment crack, are they expecting something much more vivid and dramatic than the sort of thing I posted? Do we have any idea of how soon they may have determined there was damage based on visual evidence rather than pressure readings? Because the IAEA only recently started doing the more detailed reports I am not sure if I can tell when they were first ready to acknowledge openly that visual evidence of the crack existed. Was the evidence gleaned from outside the building, or from robots? So many questions. I guess we will find out eventually, but until then what do people think of the steam escaping from the area resembling one edge of the storage pool concrete gate, is there an innocent explanation for this?

 

[Jorge Stolfi]

Specifically, there was that Japanese defence force video taken in March, and one area where stuff was billowing out always caught my eye ...
Im talking about the attached image, which as best I can tell from watching the video several times, shows stuff emerging from the area where containment could be said to begin. I am pretty sure we are looking at the steam dryer separator storage pool, and the area where the large concrete 'gate' is located which connects it to the upper part of reactor containment.
http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

Indeed that seems to be the south end of the steam-dryer storage pool, separated from the refueling pool (where the reactor opening is) by a gate consisting of several concrete blocks that slide into groves on each side. The gray horizontal band above the gate is the north longbeam of the overhead crane, now resting on the service floor roughly astride the refueling pool. (Other photos indicate that the west end of that beam sank into the service floor by a meter or so.) The steam is apparently coming from the refueling pool under the crane. Either the spent-fuel pool gate, on the other side of the refueling pool, is leaking, or the steam is coming from a leak in the primary containment (drywell or its yellow cap).

Do we know whether the shield plugs (the concrete half-discs that form the lid of the refueling pool) were in place at the time of the explosion?

 

[SteveElbows]

i've been trying to follow the posts so excuse me if i missed discussion of this one, linked yestarday i think.

http://i.imgur.com/IqCPH.jpg

wold imbed picture if knew how.

Anybody know source of the photo? Is it credible?

Can you photo capable guys offer an opinion on the snaggletooth round looking shape in the red rectangle connected by red line to reactor vessel head? It's way down in the shadows.

Well as you can tell from my recent posts, I've spent a while looking at footage of this part of reactor 3. All sorts of things jump out of the shadows, in a way that sometimes seems tantalisingly close to revealing a horror. So far none of its been enough to convince me, so I've concentrated on other areas where I am a bit more certain of what I am seeing. Even so, my stupid mistake earlier today with the live camera image, despite me being well aware of the dangers and moaning about them here several times, shows that I err when it comes to this stuff, and I am conflicted about this whole issue of overly analysing what little visual evidence we have.

However I will go back and review some footage again with the graphic you posted in mind. I can see perfectly well why a lot of people have likely thoroughly discounted all theories to do with caps flying off reactor 3 and/or its containment. Personally I am keeping a slightly more open mind, despite the evidence, simply because of how dramatic the explosion was, and because I have yet to see for myself what lurks under the debris of that part of reactor 3 building.

 

[jim hardy]

Mice & Men guess i should have been a bit more exact, i had seen 6454 and ignored it because he had reactor in wrong spot way off to one side..
so i brushed by the rebuttals of it.
i had dismissed it late last night as clutter, just my memory isn't great. Shoulda told you.

This image puts reactor exactly centered under middle roof beam, where it belongs.
[image]http://i.imgur.com/IqCPH.jpg[/image]
http://i.imgur.com/IqCPH.jpg

It is a collage - overview in center with insets around edge. At first glance it looks like a mess and is easy to dismiss as i did at first...
but it also shows the steam separator laydown and spent fuel pools in more believable locations, and at first glance the laydown area in the fellow's collage looks a lot like SteveElbows photo of it...

maybe take a second look? I wasn't referring to post 6454's photo, it's clearly way off.
This one's too foggy under roof beams to be certain of anything , just wanted to rule it out as fraud if anybody knows for sure.. look close.

And Jorge - i think a real high tide might do it. I am still needing a mechanism for slosh in the pool though.
The most recent #3 pool video looks to me like rubble piled in on top of orderly racks, an explosion in the racks should blow rubble away i'd think. If the pool looked like it was recently steam cleaned with fuel strewn about i'd be with you.
That's just my thoughts.

 

[TCups]

Can we bring the reactor 3 talk down to earth?

Specifically, since the talk of a crack in containment appears to have been confirmed in an IAEA presentation some days back, are we entirely sure that these people have seen images we havent?

Specifically, there was that Japanese defence force video taken in March, and one area where stuff was billowing out always caught my eye. I was not on this forum back then and although I did wade through many of the early pages, I do not recall whether this avenue of enquiry was picked up on at the time.

Im talking about the attached image, which as best I can tell from watching the video several times, shows stuff emerging from the area where containment could be said to begin. I am pretty sure we are looking at the steam dryer separator storage pool, and the area where the large concrete 'gate' is located which connects it to the upper part of reactor containment. Could this count as the crack that has been described, is it reasonable evidence of containment damage, or am I barking up the wrong tree?

Its taken from this video, where this scene shows up briefly at around 3 mins 8 seconds, and again at approx 3 mins 23 seconds.

http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

The steam is coming from the "north" gate area of the equipment pool (yes, there is a gate on that end too). At the same time, steam can also be seen escaping from the region of the fuel transfer chute on the south side of the upper primary containment, though it has never been clear to me that the gate for the fuel transfer chute or the chute itself were clearly visible as they are obscured by debris.

IMO, either or both would qualify as "cracks" given the escaping steam which has to be originating from the primary containment.

Addendum:

For clarity, two files are added -- both technical drawings. The first screenshot is my "alteration" of the original to show the equipment pool re-oriented 90 deg on its long axis and with color emphasis -- blue for the pools and red for the gates. The original document is also included. Sorry, I don't remember the original source for the technical drawings. Clearly they are just a bit different from Unit 3, but I suspect they are very close.

 

[jim hardy]

Thank you Steve you posted while i was typing.

i have not ruled out a neutron boost for that explosion for exact same reason as you. Something looked wrong. But i expect to find just the bolts stetched and it's still in place.

'...cold reason will prevail. ' A lincoln

 

[jim hardy]

"""at which point the zircalloy has probably been corroded and so the core collapses. """
...or turns into a crumbly pile with shape resembling a reactor. Remember Arnie's blowtorch on the zirconium tube, he had to hit his oxygen handle to melt it. What he didnt melt he crumbled away with his fingers.

 

[ascot317]

IMO, either or both would qualify as "cracks" given the escaping steam which has to be originating from the primary containment.
.

Or could be leaking water from the SFP that is getting boiled off of the containment cap.

 

[MiceAndMen]

Page 6 of this:

http://www.slideshare.net/iaea/technical-briefing-11-0505

In the containment integrity row and the observation column, the last point thing it says is:

'Images of Unit 3 show crack in the primary containment and steam released from the reactor building.'

The lack of detail is what has caused me to have room to wonder whether the images I just mentioned could be what they refer to, or whether I am looking at the right part of the building at all. For now I'd say the footage I refer to is a potential candidate, but I would welcome lots more opinion on this matter.

My bad, I did download that document but hadn't gotten around to reading it yet.

The NYT had an online article on 25 March that said the same thing. They later changed the story to remove the part about the cracked reactor. Here's the story as it appears today: http://www.nytimes.com/2011/03/26/world/asia/26japan.html

Before they changed it, the story got picked up by other news agencies and you can still find the unaltered versions on the web, such as this one from NDTV:http://www.ndtv.com/article/world/j..._campaign=Feed:+ndtv/TqgX+(NDTV+News+-+World)

Part of the text they removed reads as follows:

A senior nuclear executive who insisted on anonymity but has broad contacts in Japan said that there was a long vertical crack running down the side of the reactor vessel itself. The crack runs down below the water level in the reactor and has been leaking fluids and gases, he said.

The severity of the radiation burns to the injured workers is consistent with contamination by water that had been in contact with damaged fuel rods, the executive said.

“There is a definite, definite crack in the vessel — it’s up and down and it’s large,” he said. “The problem with cracks is they do not get smaller.”

To be fair, however, in the original story when the "senior nuclear executive" says the "reactor vessel" is cracked he must have been referring to the primary containment shell because nobody has laid eyes (or a camera) on the actual pressure vessel since the accident. At least not that I know of. On the other hand, he says the crack "runs down below the water level" and the drywell containment vessel normally doesn't have a water level. There it seems he must be talking about the RPV itself. So maybe the NYT had some doubt about what he was saying. On the other hand, maybe he was exactly right and the original story was correct and they censored that part for reasons unknown.

 

[ascot317]

Thank you Steve you posted while i was typing.

i have not ruled out a neutron boost for that explosion for exact same reason as you. Something looked wrong. But i expect to find just the bolts stetched and it's still in place.

'...cold reason will prevail. ' A lincoln

There was likely a gamma burst during/after the explosion of #3, since Tepco has talked about 12x normal radiation peak in the control bunker.

 

[SteveElbows]

Part of the text they removed reads as follows:

To be fair, however, in the original story when the "senior nuclear executive" says the "reactor vessel" is cracked he must have been referring to the primary containment shell because nobody has laid eyes (or a camera) on the actual pressure vessel since the accident. At least not that I know of. On the other hand, he says the crack "runs down below the water level" and the drywell containment vessel normally doesn't have a water level. There it seems he must be talking about the RPV itself. So maybe the NYT had some doubt about what he was saying. On the other hand, maybe he was exactly right and the original story was correct and they censored that part for reasons unknown.

Ah yes I remember seeing that at the time, but had since forgotten all about it. I suppose my main beef with the original wording is that the word containment is not used, leaving some ambiguity about exactly what he is talking about, just as you suggest.