Hiroaki Koide of Kyoto University: "Melted Core Outside the Containment Vessel"

[Barrett808]

Hiroaki Koide of Kyoto University Research Reactor Institute is quoted by Mainichi Shinbun as saying that the melted core of the Reactor 1 is not just out of the Reactor Pressure Vessel but out of the Containment Vessel.

From Mainichi Shinbun, Koide's comments only (5/16/2011):

Hiroaki Koide of Kyoto University Research Reactor Institute points out that "TEPCO could have foreseen the core melt at an early stage when the cooling of the reactor stopped due to the power failure. TEPCO's assessment that the damage to the fuel was limited has turned out to be completely wrong. The disclosure of the data came too late."

According to TEPCO, the data analysis shows that damage to the RPV is not extensive. However, Koide thinks "The RPV has been completely damaged, the melted core bore a hole at the bottom of the Containment Vessel, causing the large amount of contaminated water to leak into the ground beneath the reactor building."

Hiroaki Koide of Kyoto University: 'Melted Core Outside the Containment Vessel'

[Yo_Mama]

1. This is what I believe happened in 1 & 2. Not sure about 3. N/T

[mrJJ]

12. Meltdowns also likely occurred at No. 2, No. 3 reactors of Fukushima plant.

Meltdowns also likely occurred at No. 2, No. 3 reactors of Fukushima plant.
snip

According to the data, the pressure in the pressure vessel of the No. 2 reactor dropped at 6:43 p.m. on March 15. A similar drop in pressure also took place at the No. 3 reactor at 11:50 p.m. on March 16.

Those declines were apparently the result of holes made in the pressure vessels.

Previously, it was believed that water was leaking through holes at the bottom of the pressure vessels where measuring instruments and part of the control rod mechanisms were located.

Now, it appears that melted nuclear fuel formed new holes in the pressure vessels.

Radioactive materials, such as technetium, produced when nuclear fuel rods are damaged, have been detected in water in the No. 3 reactor building. That discovery has raised speculation that the melted nuclear fuel has breached the pressure vessel and landed in the containment vessel.

http://www.asahi.com/english/TKY201105170428.html

[dixiegrrrrl]

2. This is not good.

[FBaggins]

3. It's also not...

...likely to be true.

This guy has had a number of get-press-attention statements like this since fairly early on. I can't remember one that's been right yet.

On edit - That's not quite true depending on how you read his take on the supression pool failure in #2... which (IIRC) ranged from not far off of what I said to full-blown corium escape from primary and secondary containment - depending on who described it.

[kristopher]

4. Your assessment is worth nothing Baggins.

Hiroaki Koide on the Dream of a Nuclear Japan
September 3, 2007

...From the time when I was in high school, I was a very conservative, serious student, and at university as well, I wore a student uniform and wouldn’t miss even one hour of class. So with student activism as well, at first I just thought something to the effect of: “It’s disturbing studying.” Meanwhile, there was a plan taking shape to build a nuclear power plant at Onagawa, and local residents had started a protest movement against it. For me, someone who had embraced the dream of nuclear power, this appeared to be something completely incomprehensible. Most of the power produced at Onagawa would be consumed by the city of Sendai and surrounding areas. So then I became suspicious and asked myself: why then don’t they build the nuclear power plant in Sendai? After doing some investigating here and there, I figured out that the reason was that nuclear power is dangerous. The consensus of opinion at that time was that “nuclear power is safe,” and I had also come to believe this, but at that point I realized that, in reality, this was not the case. I then came to understand what kind of thing nuclear power really is, and on October 23rd, 1970, I joined the protests against the nuclear power plant at Onagawa.


...I used to be a member of the Atomic Energy Society of Japan. However I withdrew when the head of the former Kansai Electric Power Co. assumed the position of vice-president of the society. Although called an academic society, there are also interest groups involved. 60% of the energy supplied by the Kansai Electric Power Co. is generated by nuclear power plants such as the ones in Fukui.


...Compared to the history of this planet, the existence of humans is a very new thing. The use of electric power only started after the industrial revolution, just 200 years ago. If we don’t change the way we think, there is no question that we will destroy ourselves. Changing a way of thinking is also about how much you can recognize about other problems. If you think about the problem of nuclear power, you become aware of many other problems as well. I think of the issue of nuclear power as grounds not for “opposition” (反対) but for “resistance” (抵抗). This is because, as I mentioned earlier, the problem of nuclear power is a problem of discrimination. Among the people in the movement against nuclear power plants, there are many people who “break with nuclear power generation”, in other words they adopt a lifestyle which does not require nuclear power. In its own way, I think that this is good. However, I am thoroughly and absolutely resisting nuclear power. In order not to be crushed by the government or large organizations, it is necessary to resist. I think that if people see that, of the entire world population, one quarter of all humans are consuming nearly all of the world’s energy, and that, in Japan, as a result of nuclear power, some people are suffering, then I think that people’s judgements and actions will change a bit.

http://genpatsu.org/hiroaki-koide-nuclear-japan/


************************************

Just as the nuclear industry does with EVERY SINGLE PERSON AGAINST NUCLEAR POWER you are doing nothing but engaging in character assassination.

[FBaggins]

5. Pointing out that he's been wrong so far is not "character assasination"

As if you have even a tiny amount of credibility accusing anyone else of character assasination.

And what was the point of pasting the rest of the spam? How is it responsive?

There isn't any reason to believe that the core itself has broken through all containment and plenty of reasons to believe that it hasn't.

Just take his own statements prior to this claim where he tells us about the massive explosion that would occur if that happened. There hasn't been such an explosion, has there? So was he wrong in describing what such a breach would be like... or that it has happened?

[marions ghost]

11. +++

:thumbsup: Koide

[Yo_Mama]

6. One thing we can be sure of

It will be a long, long time before we know.

It seems as if the water in 1 just goes straight into the containment and from there straight somewhere else. I'm relying on TEPCO's statements in saying that - they keep claiming that there's not much water in the reactor vessel and not much in the containment vessel. This implies kind of big holes and not just the minor seal leaks most were expecting.

Following the KISS principle, it does seem most likely that the same cause produced these very big leaks.

The reasons I suspect he is right are several: First, there are relatively low levels of radiation on most of the second floor. This implies that most of the water is going down. If it was steaming off and going up, you'd expect the second floor to be damned hot.

Second, early on they should have been dealing with much hotter fuel, yet they were able to inject less water. The temps started rising in these reactors, and they had to increase injection rates. For example, on April 28th they increased from six tons an hour to 10 tons an hour. Now, it appears that the reactor vessel is leaking at least six-eight tons an hour of water. That's a lot. It's flowing out of the containment vessel nearly as fast, or perhaps even faster.

I am sure they are using metric tons, so 1,000 kilograms, so 2,204 pounds each ton, or about 275 gallons per ton, so the pressure vessel is clearing about 1,650 - 2,200 gallons of water an hour, say 30 gallons a minute. That's a very substantial aperture; it's as if you filled up your bathtub, then opened the drain, and it drained in a minute. That would be a pretty big pipe! Since they say there is almost no water in the vessel, and that the fuel is on the bottom head, we know the water is not flowing out of the pipes up above that head.

It seems as if 3 is now moving into the increased temperature cycle; I am sure that occurs because the flow rate through the vessel increases, which apparently means that the hole or holes at the bottom gets bigger.

There are a few things we know. First, the flow is going to be turbulent, because TEPCO said the reason they thought there was water in there was that the water sensor was pressured by steam. So as water is injected, a considerable portion of it flashes into steam, rises up, condenses, and runs back down. It's pressured.

The equation for non-turbulent water flow is:
Flow rate =(Pi (radius^4) (Pressure1 - Pressure2))/(8*Viscosity*Length)

Turbulence might slow flow; we can assume that the length is 2-4 inches, I'm not sure what the viscosity of boiling water is but it is probably between .3 & .6, and I would guess that Pressure1 is greater than Pressure2.

Maybe an engineer will show up to save us. Calling all engineers!

The problem is that the hole will not be round. Assuming low viscosity, that shouldn't matter much. Somewhere around 2.5 inches if it were round. The whole idea that there are tiny leaks/cracks doesn't really make sense (although there should be from seal degradation), because with hot, very thick metal you would expect water running in there to be flashed into steam, thus exerting pressure back out, admittedly on both ends but more so on the inner end. No, it has to be a relatively big hole to get flow rates like that.

It could be a jagged hole four or five inches around!

[FBaggins]

7. Does it have to be "a long time"?

See my last reply to kristopher.

A number of posters here have told us what would happen if one of these cores escaped containment (by which, of course, we mean something very different from water leaking out of a busted pipe/seal/whatever). Those comments pretty closely match what the professor in the OP also said would happen in such an event.

So we can either assume they knew what they were talking about and be comforted that it hasn't happened... or we can assume that they don't know what they're talking about... in which case their notion that the core is outside of all containment isn't worth much.

It seems as if the water in 1 just goes straight into the containment and from there straight somewhere else.

Yep. And it's been pretty clear since early on that this was the case in at least one of the other two reactors. If someone wants to call that a "containment breach" that's fine with me. But the primary purpose of the containment structure is to "contain" the core. As stated by those posters mentioned above... a core getting entirely out of containment would be a MUCH more signficant event. We wouldn't be talking about levels that would give an unprotected man a year's dose in less than an hour... we would be talking about "he rounded the wrong corner and got a lethal dose in seconds".

[SpoonFed]

8. Bah, eating your cake too.

A number of posters here have told us what would happen if one of these cores escaped containment (by which, of course, we mean something very different from water leaking out of a busted pipe/seal/whatever).

Oh, wait, those other posters are correct in your mind with regards to this thread, just not correct in regards to the other thread?

Typical of your BS doublethink.

[FBaggins]

9. Still with the poor reading comprehension, eh?

The point is that their positions are mutually exclusive. If the core IS outside of all containment, then they were wrong about what the consequences of that would be... if they were right about what the consequences would be, then they're wrong that it's outside of containment.

But no, I never said that anyone was wrong about how serious the consequences would be if a core burned though all containment. When comparing Fukushima to Chernobyl, the fact that the core was not in containment has been constantly identified as one of the key differences for why the current events are not as serious as those were... so if you can put two and two together, you can see that such a poster would think that an escaped core would be a pretty serious event.

[AtheistCrusader]

14. Please re-read his post.

You have missed something.

[Yo_Mama]

10. I just never felt the China-syndrome explosive drama was that likely

Not in this scenario, with flooded infrastructures and ongoing water injection.

I think it is quite likely that hunks of the core, blended with concrete, are through the bottom of the drywell, at least. They could be down in the basement; they could be in the concrete subflooring. If they are down in the basement under that water, it's containment of a sort. Not containment as designed, but a type of water entombment.

As for containment, there are three levels (integrity of fuel assemblies, integrity of reactor vessel, integrity of containment vessel). All three are breached in reactor 1, and probably in both the others.

Once the fuel assemblies have melted down, even if you just have small water leaks the radioactivity will be leaking out in particles and gases. Given what TEPCO is telling us, quite frankly most of the fuel is probably safer if it is down in the basement.

Once active fission ends, and you have only decay emissions, I don't think you would have whomping high levels if some of the fuel was in the basement under that water. The problem is more that some of it is still in the drywell or substructure.

There was something going on, because they were detecting neutron emissions over a kilometer from the plant on the 16th. Shit definitely happened.

[AtheistCrusader]

13. There are pipes of significant size that pass through the containment walls, with valves.

One of those valves may be stuck open, or blown open with the pressure.

Based on the available symptoms, it seems unlikely the core has penetrated the base of the containment.

[FBaggins]

16. Exactly right.

Water leaking out never meant that molten corium had necessarily also escaped. The damage to the suppression pool of #2 would seem (to me) to be better evidence of the possibility, but that's another discussion.

It certainly doesn't show that the primary containment vessel no longer contained the core.

[mrJJ]

15. Japanese MP : Kuniko Tanioko

Japanese MP: It's Time to Tell the Truth
Kuniko Tanioko May 7th

http://therealnews.com/t2/index.php?option=com_content&task=view&id=31&Itemid=74&jumival=6729

[SpoonFed]

17. Oh darn

This is another one of those you're-proven-wrong-within-24-hours by a reputable news source.

Ouch.