Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[SteveElbows]

Just a few days later, a couple of employees were "lost" and assumed dead as they were out reading radiation data. I think they were later found in or around the turbine buildings dead.

They were reported missing long before the explosions, and they are presumed to have been killed by the tsunami. If you go back and check early press releases about the nuclear emergency, mention of these missing workers turns up quite early, removing the possibility that they died much later during the explosive days.

I had hoped that your flawed and sloppy photo analysis had been put to rest days ago. Your analysis of the roof damage remains very poor, and I don't know what else to say about that since people already explained it to you days ago.

 

[Jorge Stolfi]

molten corium, of low thermal conductivity, mixes up with stuff, dilutes, the heat output decays, etc. ... low thermal conductivity, and freezes on contact.

Inuition gained from experience with ordinary molten metal and lava does not apply to corium.

If you dilute very hot molten metal with cooler molten stuff, such as concrete, it will immediatly cool down and remain cool. If you confine a ton of liquid metal in a closed container, it will stay there and slowly cool down. If you cool the surface of a lump of lava, it will form a solid, relatively cool crust and then slowly cool down throughout.

None of these "common sense facts" seem to apply to corium, because its radioactive contents will continue to generate heat from "nowhere" at the same total rate, no matter how much it is diluted or how it is confined. (Mixing with boron can prevent it becoming critical but has absolutely no effect on the decay heat generation.) If that heat has nowhere else to go, the corium will keep getting hotter and hotter until it boild away. (And even then the vaporized material will continue generating heat at the same rate.) If you dlute the corium 100 fold with molten concrete, and then keep that mass isolated, the rate at which its temperature increases with time will be reduced a 100 fold perhaps, but it will remain positive. So the entire mass --- original corium plus mixed concrete --- will continue to get hotter and hotter without limit; it will only take 3 months to reach the boiling point, instead of a day.

If the mass is not isolated but buried in soil or concrete (as in the "China syndrome" scenario), the temperature will tend to a limit when the heat produced inside the mass is equal to the heat lost to the medium. However, since concrete is a rather poor heat conductor, the equilibrium temperature inside may still be quite high --- as the lava example illustrates,

In this case dilution will help because it will increase the area available for heat to flow through into the cooler medium. An 8-fold dilution of the radioactive material will increase its surface area 4-fold; meaning that the temperature gradient at the surface (for the same total heat generation and dissipation) will be reduced to 1/4. However, since the radius of the mass is twice as large, the equilibrium temperature at the center should be reduced only by about one half. Now, if I read the posts correctly, the equilibrium temperature for an undiluted molten Fukushima fuel load is greater than 3000C. So it is not surprising that in Chernobyl the corium kept melting through several concrete floors, even though it was being diluted along the way.

I wonder if anyone has modeled the "China syndrome" scenario in more detail, namely how exactly the molten core would flow and get diluted once it gets surrounded by soil or concrete.

 

[ihatelies]

They were reported missing long before the explosions, and they are presumed to have been killed by the tsunami. If you go back and check early press releases about the nuclear emergency, mention of these missing workers turns up quite early, removing the possibility that they died much later during the explosive days.

I had hoped that your flawed and sloppy photo analysis had been put to rest days ago. Your analysis of the roof damage remains very poor, and I don't know what else to say about that since people already explained it to you days ago.

Steve pardon, but your analysis of my analysis is nonexistent, except for the fact that you say it's wrong.

So If you don't have anything scientific to add, I'd suggest you leave it to those who do.

 

[WhoWee]

https://www.physicsforums.com/showpost.php?p=3304969&postcount=7484", and some earlier posts of that thread.

Wasn't that de-bunked as re-bar a few thousand posts ago?

 

[ihatelies]

They were reported missing long before the explosions, and they are presumed to have been killed by the tsunami. If you go back and check early press releases about the nuclear emergency, mention of these missing workers turns up quite early, removing the possibility that they died much later during the explosive days.
.

They were not reported missing before the explosion. They were reported missing on March 16, the day after the explosion, and clearly the press release said they were missing due to the explosion.

http://www.theaustralian.com.au/news/breaking-news/cracked-roof-two-missing-workers-at-fukushima-reactor-no4/story-fn3dxity-1226022252864

They were found about two weeks later, dead because the lost blood and went into shock.

http://www.businessinsider.com/fukushima-two-missing-workers-found-dead-2011-4

There does seem to be an effort after the fact to say they were a victim of the Tsunami, not the explosion - wonder why?

 

[Rive]

Wasn't that de-bunked as re-bar a few thousand posts ago?

Please be more specific - which part do you think was debunked?

 

[zapperzero]

If the mass is not isolated but buried in soil or concrete (as in the "China syndrome" scenario), the temperature will tend to a limit when the heat produced inside the mass is equal to the heat lost to the medium. However, since concrete is a rather poor heat conductor, the equilibrium temperature inside may still be quite high --- as the lava example illustrates

It's not only heat loss through conduction because in the meantime the concrete is "burning". Lots of gases are produced which may carry some heat out. This might be enough to drop the temperature of the outer layer to something beneath the melting point of the corium and keep it there, forming a crust which after a time cracks, "fizzles" then solidifies again.

Also, in this real-life example, we also have some water that gets turned to steam, carrying even more heat away.

I'm saying, I guess, that the core may be moving downward much slower than you seem to imagine.

 

[WhoWee]

Please be more specific - which part do you think was debunked?

The metal objects covered by bulldozers was de-bunked to be re-bar - correct?

 

[SteveElbows]

They were not reported missing before the explosion. They were reported missing on March 16, the day after the explosion, and clearly the press release said they were missing due to the explosion.

Rubbish, I know for a fact that their status as missing persons was mentioned before any explosions. This is because I do actually have a suspicious mind myself, so I like to check the details, and I have already looked into this matter in the past. Unlike some people I am not so desperate to find a gloomy picture that I feel the need to be excessively sloppy or deliberately avoid evidence that contradicts my instincts, if I see reasonable evidence then I reduce my suspicions accordingly.

Here, very near the end of this document:

http://www.tepco.co.jp/en/press/corp-com/release/11031217-e.html

Further, there are 2 TEPCO employees whose presence has not been confirmed.

Regardless of the poor language, I am satisfied that they are talking about the two workers who were later found dead in turbine 4 building.

 

[clancy688]

Here's an interesting hypothesis regarding the spent fuel pools and explosions:

http://tec-sim.de/images/stories/fusfpfail.pdf

 

[Rive]

The metal objects covered by bulldozers was de-bunked to be re-bar - correct?

Nancy of Houseoffoust discussed some 'possible fuel rods' between U3 and U4 right after the explosions. Those were identified as I-beams from the roof later IIRC. If it's what you are thinking of then you are right, it was de-bunked.


Otherwise the NRC document mentions only 'very high dose material' bulldozed over without any further details. I can't recall any further (official) information. (Which does not means that there is nothing more about this, of course.) IMO this part is hardly important - there were the pieces of the previously used venting pipe, and there were the explosion itself. 'High dose material' could be anything, but what's more or less sure: it was not 'high dose' on 'Chernobyl scale', so they weren't (irradiated) fuel assemblies/rods/pieces.

 

[WhoWee]

Nancy of Houseoffoust discussed some 'possible fuel rods' between U3 and U4 right after the explosions. Those were identified as I-beams from the roof later IIRC. If it's what you are thinking of then you are right, it was de-bunked.

Yes, although I thought it was re-bar (not I-beams) - my mistake.

 

[zapperzero]

OK thanks for the response. Your rephrasing my question is not exactly what I meant.
I meant - did the plug, the containment cap, the nuclear fuel or the entire RPV eject in the explosion.

The RPV could not have ejected . It's big. We would have seen it.

We would have seen the plug. Ditto for the cap. Huge, hot, radioactive things, can't miss them.

Please, try to get a grip on the dimensions involved. For all your doom-and-gloom outlook, you seem to be constantly underestimating things. For instance, you are confused about the amounts of radiation that would be given off if a significant fraction of the core were to be ejected.

We're NOT talking pieces radiating a piss-ant 0.9 Sv/h that you can bulldoze over and go on with your day. Your scenario implies white-hot (1000 at least, but probably closer to 3000 degrees Celsius) corium dust and droplets and drops and blobs and bits of low-power rods from the outside of the core that may be "only" 900 degrees or so. They would be burning anything they land on, starting masses of secondary fires. The bigger bits would be vaporizing and cracking and spalling under thermal stress, giving off doses in the tens/hundreds of Sievert per hour, not that anyone or anything could get close enough to do contact readings. In the meantime, the finer stuff would be falling and depositing on every surface, a powder deadly to inhale, radioactive enough to kill you in hours or days. You'd get a Sievert or two worth of gamma just from staring at the site or the plume from two kilometers away, like those poor curious fellows who stared into the burning reactor from a bridge in Pripyat.

Good thing anything like that didn't happen, eh?

 

[Jorge Stolfi]

AFAIK, the space just below the reactor pressure vessel is densely packed with pipes, cables, and the hydraulic actuators of the conctrol rods. So any corium that breaches the RPV will have to melt through or flow around that mess before it reaches the concrete cap at the bottom of the drywell.

Could it be that the black smoke of #3 was caused by corium coming in contact with the hydraulic fluid of the actuators? The oil could have either burned inside the drywell, with whatever oxygen remained there, or it may have been vaporized and burned after escaping the drywell.

It seems that the steam emitted by #3 is leaking from the primary containment (into the refueling opening, and escaping from there through gaps around the service pool gates). The black smoke apparently came from the same area -- i.e. the service floor, as opposed from the lower levels. There seems to be little on the service floor that could burn.

 

[imandylite]

British Government interim report on the Fukushima accident:

http://www.hse.gov.uk/nuclear/fukushima/interim-report.pdf"

The report is a precursor to the expansion of UK nuclear plant facilities.

Much detail on the Fukushima accident and some interesting conclusions.

Conclusion 1: In considering the direct causes of the Fukushima accident we see no reason for curtailing the operation of nuclear power plants or other nuclear facilities in the UK. Once further work is completed any proposed improvements will be considered and implemented on a case by case basis, in line with our normal regulatory approach.

Conclusion 2: In response to the Fukushima accident, the UK nuclear power industry has reacted responsibly and appropriately displaying leadership for safety and a strong safety culture in its response to date.

Conclusion 3: The Government’s intention to take forward proposals to create the Office for Nuclear Regulation, with the post and responsibilities of the Chief Inspector in statute, should enhance confidence in the UK’s nuclear regulatory regime to more effectively face the challenges of the future.

Conclusion 4: To date, the consideration of the known circumstances of the Fukushima accident has not revealed any gaps in scope or depth of the Safety Assessment Principles for nuclear facilities in the UK.

Conclusion 5: Our considerations of the events in Japan, and the possible lessons for the UK, has not revealed any significant weaknesses in the UK nuclear licensing regime.

Conclusion 6: Flooding risks are unlikely to prevent construction of new nuclear power stations at potential development sites in the UK over the next few years. For sites with a flooding risk, detailed consideration may require changes to plant layout and the provision of particular protection against flooding.

Conclusion 7: There is no need to change the present siting strategies for new nuclear power stations in the UK.

Conclusion 8: There is no reason to depart from a multi-plant site concept given the design measures in new reactors being considered for deployment in the UK and adequate demonstration in design and operational safety cases.

Conclusion 9: The UK’s gas-cooled reactors have lower power densities and larger thermal capacities than water cooled reactors which with natural cooling capabilities give longer timescales for remedial action. Additionally, they have a lesser need for venting on loss of cooling and do not produce concentrations of hydrogen from fuel cladding overheating.

Conclusion 10: There is no evidence to suggest that the presence of MOX fuel in Reactor Unit 3 significantly contributed to the health impact of the accident on or off the site.

Conclusion 11: With more information there is likely to be considerable scope for lessons to be learned about human behaviour in severe accident conditions that will be useful in enhancing contingency arrangements and training in the UK for such events.

 

[etudiant]

It would seem that there is a general agreement that all three reactors have had their fuel melted.
Presumably this means that all volatiles in the reactor fuel have been expelled.
What does this translate to, in objective terms?
The initial estimates were for about 10**17 bequerels from iodine alone. These estimates were made before there was any thought that all 3 reactors had gone bust.
Are there any new estimates that can now be made?

 

[ihatelies]

The RPV could not have ejected . It's big. We would have seen it.

We would have seen the plug. Ditto for the cap. Huge, hot, radioactive things, can't miss them.

Please, try to get a grip on the dimensions involved. For all your doom-and-gloom outlook, you seem to be constantly underestimating things. For instance, you are confused about the amounts of radiation that would be given off if a significant fraction of the core were to be ejected.

We're NOT talking pieces radiating a piss-ant 0.9 Sv/h that you can bulldoze over and go on with your day. Your scenario implies white-hot (1000 at least, but probably closer to 3000 degrees Celsius) corium dust and droplets and drops and blobs and bits of low-power rods from the outside of the core that may be "only" 900 degrees or so. They would be burning anything they land on, starting masses of secondary fires. The bigger bits would be vaporizing and cracking and spalling under thermal stress, giving off doses in the tens/hundreds of Sievert per hour, not that anyone or anything could get close enough to do contact readings. In the meantime, the finer stuff would be falling and depositing on every surface, a powder deadly to inhale, radioactive enough to kill you in hours or days. You'd get a Sievert or two worth of gamma just from staring at the site or the plume from two kilometers away, like those poor curious fellows who stared into the burning reactor from a bridge in Pripyat.

Good thing anything like that didn't happen, eh?

You assume I think that a nuclear explosion occurred. I did not say that.

I know exactly the size of the things that I'm talking about. So please stick to the facts, instead of the commentary.

If you can prove me wrong I will shut up.

First tell me what went through the hole.

Second tell me what has been burning in "masses of secondary fires" for eight weeks on the northwest corner of the #3 reactor building wreckage.

Third, tell me how the spent fuel pool - if that's where the explosion occurred, could have blown up the rest of the building, without destroying itself.

Facts:
1. something very big and round went through the roof right above the reactor core location.

2. Something has been burning on the northwest corner of the building for weeks, rendering that area a charred mess, with big holes going at least into the basement.

3. Tepco said for weeks the pressure vessel was intact and gave temp and pressure readings, which all must have been fabricated, since they now admit the fuel has probably melted through the RPV.

4. Some people did die in the explosion - possibly just as you have described - Internal bleeding and shock - like.


I'm not familiar with where you get your knowledge of exactly what would happen in an explosion scenario - as far as I know it's never happened before like this - so your speculation and detailed description is simply that - speculation.

I'm not a doomsdayer. I'm a realist. I'm happy to be proven wrong, but the facts support what I'm saying, no matter how much you wish they didn't.

 

[ihatelies]

Here's an interesting hypothesis regarding the spent fuel pools and explosions:

http://tec-sim.de/images/stories/fusfpfail.pdf

Interesting analysis, but the fatal flaw is an assumptive jump between the pages quoted below.

4) Basic facts are that there do not exist many potential sources of explosion or pressure surge in a nuclear reactor.
The most important hazard is hydrogen production: hydrogen can be produced either in the reactor pressure vessel (RPV) or in the spend fuel pool. As long as the containment does not fail, no hydrogen from the RPV can escape into the reactor building. A hydrogen explosion can be a detonation characterized by a shock wave or a deflagration characterized by a somewhat smoother pressure surge. Another source of explosion can be a rapid evaporation, when water comes into contact with hot structures, e.g. reflooding of some overheated fuel elements. The most dangerous source of explosion is a restart of the chain reaction, but this can be ruled out by basic physics.

So, the hydrogen has to come from the spent fuel ponds. Hydrogen in the spent fuel pond can be produced by the zircon-steam-reaction which is a strong exothermic reaction and starts when the fuel elements are not cooled properly and heat up to temperature above 1500°C.

In the first paragraph he says there are two possible sources for hydrogen, then in the second he jumps the spent fuel as being the cause.

Presumably because he makes the assumption the containment was not breached so it couldn't be the RPV, but we now know the containment has been breached on 1,2 and 3.

So that jump cannot be made.

Seems like the same jump that several here have incorrectly made.

 

[SteveElbows]

I'm not a doomsdayer. I'm a realist. I'm happy to be proven wrong, but the facts support what I'm saying, no matter how much you wish they didn't.

Rubbish. You are not at all happy to be proven wrong, to the extent that you ignore evidence presented here and end up winding up people like me as a result.

For example in your last post you talk as if rpv temperatures are a fabrication. What are you basing that on? An what's this rubbish you are talking about uncontrolled fires raging for weeks at north of building?

Furthermore, you complain that I did not sensibly analyse your stupid 'round holes in roof' stuff. In fact I told you that those areas do not appear round from the other angles for which we have photographs available, but you just ignore that because it does not fit your theories, theories which you are clearly well attached to despite a lack of evidence.

 

[zapperzero]

Could it be that the black smoke of #3 was caused by corium coming in contact with the hydraulic fluid of the actuators?

Could be anything, but there's relatively little fluid. Could be metal, could be carbon from the seals, could be concrete that's burning. Tepco should have flown something through the plume and gotten samples, but perhaps they were busy with other things.

 

[pdObq]

I wonder if anyone has modeled the "China syndrome" scenario in more detail, namely how exactly the molten core would flow and get diluted once it gets surrounded by soil or concrete.

I'm saying, I guess, that the core may be moving downward much slower than you seem to imagine.

You might want to check out this document: http://www.ornl.gov/info/reports/1981/3445600211884.pdf . It's a simulation and analysis of station blackout scenarios at Browns Ferry unit 1 from 1982.

Lots of plots of various reactor parameters (pressures, temps, hydrogen production, etc) versus time after LOCA for lots of accident and operator action scenarios.

Attached is a snapshot of a plot showing drywell concrete penetration versus time (p.145). I think it's much faster than one would imagine -- 7m in about 6 hours .

Credit for finding that document goes to Jim Hardy afaik, https://www.physicsforums.com/showthread.php?p=3299953#post3299953 (see also https://www.physicsforums.com/showthread.php?p=3304173#post3304173 ).

NUCENG found another such study for Browns Ferry from 1985 that is more condensed (by a factor 10...), but the plots look qualitatively very similar and so are the timescales, http://www.osti.gov/bridge/servlets/purl/6402578-Rr9xTe/6402578.pdf . See his post https://www.physicsforums.com/showthread.php?p=3304320#post3304320.

 

[ihatelies]

Rubbish. You are not at all happy to be proven wrong, to the extent that you ignore evidence presented here and end up winding up people like me as a result.

Seems to me you don't have much information on my happiness or not. I'll admit, I don't bowl over to personal attacks easily.

For example in your last post you talk as if rpv temperatures are a fabrication. What are you basing that on? An what's this rubbish you are talking about uncontrolled fires raging for weeks at north of building?

If the fuel melted and the RPV breached early on, as they have admitted in #1, then yes the temps and pressures they've been issuing for weeks do seem pretty suspect, don't they?

As far as the fires. Look at the pictures. Look at where the smoke has been emanating for weeks. Look at where they have been pumping water from fire trucks.

Furthermore, you complain that I did not sensibly analyse your stupid 'round holes in roof' stuff. In fact I told you that those areas do not appear round from the other angles for which we have photographs available, but you just ignore that because it does not fit your theories, theories which you are clearly well attached to despite a lack of evidence.

OK, because a round hole doesn't look round from another view means it doesn't exist - right? Do you really mean to say that?

Last time, you said you couldn't find the holes, but you vehemently argued with me about it, then when I posted this picture of it you then said "oh I saw that all along, but didn't know what you're talking about.

And maybe it's just you calling my analysis stupid and wild, without any facts to refute - or at least anything logical, that makes me discount your opinion somewhat.

 

[pdObq]

I meant - did the plug, the containment cap, the nuclear fuel or the entire RPV eject in the explosion.

The RPV could not have ejected . It's big. We would have seen it.

Well, I don't want to get into that battlefield, but the thought of the RPV launching like a steam rocket is just hilarious .
The holes in the bottom for the control rods would make great nozzles, too. And the steam and water nozzles would be great for steering. Oh my .

Sorry, if your intention was more like "all the contents of the RPV were ejected". (BTW there is also the big heavy steam dryer and separator assembly in the way between the core and the RPV head cap.)

Anyway, would you guys mind settling this outside, i.e. in a new thread or via PMs ?

 

[zapperzero]

You assume I think that a nuclear explosion occurred. I did not say that.
I know exactly the size of the things that I'm talking about.

You have no idea, and no wish to learn. I did not say anything about a nuclear explosion. That's a straw man you set up all by yourself.

I am talking about the aftermath of ANY kind of event that could have dumped core all over the countryside. You wish to posit that the Gojira stuck a pipe into the bottom of the RPV and blew out some molten uranium like a spolied brat with a slurpee? Fine. Same result.

This is getting tiresome, really. Especially the part where you repeatedly fail to understand just how deadly that fuel is. No-one could be working on site. No-one could go there unprotected and survive. No, Tyvek overalls do not count.

The situation is bad enough as it is, no need to imagine things.

 

[zapperzero]

Anyway, would you guys mind settling this outside, i.e. in a new thread or via PMs ?

I'm just about done with this. I wouldn't mind, either way.

 

[Bandit127]

Inuition gained from experience with ordinary molten metal and lava does not apply to corium.

If you dilute very hot molten metal with cooler molten stuff, such as concrete, it will immediatly cool down and remain cool. If you confine a ton of liquid metal in a closed container, it will stay there and slowly cool down. If you cool the surface of a lump of lava, it will form a solid, relatively cool crust and then slowly cool down throughout.

None of these "common sense facts" seem to apply to corium, because its radioactive contents will continue to generate heat from "nowhere" at the same total rate, no matter how much it is diluted or how it is confined. (Mixing with boron can prevent it becoming critical but has absolutely no effect on the decay heat generation.) If that heat has nowhere else to go, the corium will keep getting hotter and hotter until it boild away. (And even then the vaporized material will continue generating heat at the same rate.) If you dlute the corium 100 fold with molten concrete, and then keep that mass isolated, the rate at which its temperature increases with time will be reduced a 100 fold perhaps, but it will remain positive. So the entire mass --- original corium plus mixed concrete --- will continue to get hotter and hotter without limit; it will only take 3 months to reach the boiling point, instead of a day.

If the mass is not isolated but buried in soil or concrete (as in the "China syndrome" scenario), the temperature will tend to a limit when the heat produced inside the mass is equal to the heat lost to the medium. However, since concrete is a rather poor heat conductor, the equilibrium temperature inside may still be quite high --- as the lava example illustrates,

In this case dilution will help because it will increase the area available for heat to flow through into the cooler medium. An 8-fold dilution of the radioactive material will increase its surface area 4-fold; meaning that the temperature gradient at the surface (for the same total heat generation and dissipation) will be reduced to 1/4. However, since the radius of the mass is twice as large, the equilibrium temperature at the center should be reduced only by about one half. Now, if I read the posts correctly, the equilibrium temperature for an undiluted molten Fukushima fuel load is greater than 3000C. So it is not surprising that in Chernobyl the corium kept melting through several concrete floors, even though it was being diluted along the way.

I wonder if anyone has modeled the "China syndrome" scenario in more detail, namely how exactly the molten core would flow and get diluted once it gets surrounded by soil or concrete.

Is it possible that the hydrogen that needed to be purged out by the nitrogen in Unit 1 came from a corium/concrete reaction?

Sorry, I only have a cartoon reference for this:
http://en.wikipedia.org/wiki/Corium_(nuclear_reactor)#Corium-concrete_interactions"

 

[ihatelies]

You have no idea, and no wish to learn. I did not say anything about a nuclear explosion. That's a straw man you set up all by yourself.

I am talking about the aftermath of ANY kind of event that could have dumped core all over the countryside. You wish to posit that the Gojira stuck a pipe into the bottom of the RPV and blew out some molten uranium like a spolied brat with a slurpee? Fine. Same result.

This is getting tiresome, really. Especially the part where you repeatedly fail to understand just how deadly that fuel is. No-one could be working on site. No-one could go there unprotected and survive. No, Tyvek overalls do not count.

The situation is bad enough as it is, no need to imagine things.

You are definitely incorrect when you say that I don't understand how deadly this stuff is. I do.

And I'm glad we can agree on that point.

Now what caused the hole?

 

[SteveElbows]

As far as the fires. Look at the pictures. Look at where the smoke has been emanating for weeks. Look at where they have been pumping water from fire trucks.

Sometimes it feels like we are looking at completely different planets! Have you actually looked at the stuff that is sometimes visible coming from reactor 3? Well for a start we are limited in what we've been able to see, we don't get great closeups all the time and on the live feed there is a cooling structure that obscures much of our view of reactor 3. But on the occasions where we do have photo or video that shows reactor 3 clearly, we can say a few things about what we see. Steam or whatever it is, is sometimes visible coming from areas of the building that are close to the reactor itself. There is some real good footage shot in march which shows this stuff coming out from the side of to the removable concrete that separates the equipment storage pool/pit from the reactor, which is towards the north of the building. To the south we see stuff that is either coming from the fuel pool, or from the reactor area. And sometimes, perhaps depending on wind direction or other factors we cannot judge, it looks like the steam is escaping from more directly above the reactor. None of these match your dodgy description of fires to the north west of the building, to the point where I even wonder if you know your north from your south. Seriously, what fires are you taking about, that's the part of the building which has slumped and unless I've missed something in a big way, this area of the building has not been doing interesting things at all.

OK, because a round hole doesn't look round from another view means it doesn't exist - right? Do you really mean to say that?

Let me put it this way. If I had a passionately held theory that there was a clearly round hole in the roof, that simply must have been made by a round object, then I would expect to be able to see signs of this from more than one angle. But in fact numerous angles show pretty clearly that the round shape that our minds may try to form, barely even exists from one angle, let alone when viewing the roof sensibly from multiple angles. Why is it so hard for you to grasp the idea that if you take a range of square and triangular shapes, and bend some of the straight pieces slightly, rip others off entirely, and have others overlapping or bending in the vertical axis, all sorts of vaguely round shapes may be formed by the mind, but in fact this in no way counts as evidence that something round has exited through the roof?

Last time, you said you couldn't find the holes, but you vehemently argued with me about it, then when I posted this picture of it you then said "oh I saw that all along, but didn't know what you're talking about.

Actually last time I said that there were multiple areas of roof which the mind could see is round shapes if it wanted to, and I wanted to know which of these you were talking about. When you finally posted an image I knew which one you meant. So simply put, I wanted to know which of the areas of roof that the human mind could erroneously decide are round, was the one that caused you to be so darn sure of your theory. And now that I know just how flimsy your evidence is, the onus really is on you to come up with better evidence. Its not my fault your evidence is so poor to the point that it hardly even needs detailed analysis to dismiss it. But some other people did a far better job than me of disputing this evidence, I may be making it too easy for you to argue with me because I am unable to make my case in language that is clear and concise.

This is a physics forum. I came here because there seem to be plenty of people with knowledge in a variety of important fields who could help us all to understand the technical evidence that steadily emerges. But somehow in the last 10 days this thread has sometimes descended into the kind of shabby photo analysis that has long been associated with the internet & conspiracy theories as a whole, and it makes me very sad. Especially as large amounts of technical data have emerged in recent days, data I am simply dying to see people with knowledge describe and discuss. Now this is not to say that all photo analysis is pointless, far from it, but I could do without the wacky theories that fail to garner any kind of support, or hysteria about leaning buildings.

 

[zapperzero]

Attached is a snapshot of a plot showing drywell concrete penetration versus time (p.145). I think it's much faster than one would imagine -- 7m in about 6 hours .

In their scenario, no-one is pumping water into the drywell. I don't know... the core may be out of the drywell, or not.

You know what I don't understand? TEPCO is pumping water in, using existing piping. If they can do that, they can also push a flexible borescope in, without altering their setup or opening additional valves or anything. Why aren't they?

 

[SteveElbows]

OK I apologise if that stuff is derailing the thread, I am just going to ignore it from now on and try to draw attention to more technical aspects of the disaster.

Has anybody been looking more at the wealth of plant parameters from the first hours after the earthquake hit? We already know from other news that they show a cooling system at reactor 1 went off, and that TEPCO think staff turned it off. So I've been looking more at reactors 2 and 3, and in particular their RCIC systems. Because looking at some graphs, it seems that these came on, and then went off again, and then came back on again a while later. And I wondered if anybody could shed light on this stuff? I will go and pull out the data that I am talking about now so that I can point anybody who is interested int he right direction.