Hydrogen gas or steam explosion? Unit 3 March 14

[Fledermaus]

In this image made off Japan's NTV/NNN Japan television footage, smoke ascends from the Fukushima Dai-ichi nuclear plant's Unit 3 in Okumamachi, Fukushima Prefecture, northern Japan, Monday, March 14, 2011. The second hydrogen explosion in three days rocked Japan's stricken nuclear plant Monday, sending a massive column of smoke into the air and wounding 11 workers. (AP Photo/NTV/NNN Japan)
http://www.grandforksherald.com/event/image/id/43459/headline/Japanese%20nuclear%20plant%20explosion/

Where's the corium now?

[FBaggins]

1. Neither.

It's obviously a whale blowing a km behind the reactor.

They were the ones who caused the earthquake you see... in retribution for japanese whale killing.

It's their version of "the finger".

[Fledermaus]

4. The media has reported that some of the explosions were steam explosions.

Where's the corium now?

[FBaggins]

10. It's possible that the one in #2 was.

Still don't know the mechanism that buster that torus.

I doubt that the one in your photo was, but I'm just guessing. I can't think of a source for one that big that doesn't involve the core, and there isn't one involving the core that wouldn't also result in far higher radiation levels at the plant. Not something they would be measuring in microsieverts.

Nor would them be able to report the temperature and pressure inside the reactor as they have.

[Fledermaus]

12. Squirt steam and molten corium out the bottom through the control rod ports.

Then blow the lid off the top of the containment building leaving the vessel leaking in a hole.



Yes, the design is similar to Chernobyl! They all have removable lids for refueling. Where is the containment dome?

[FBaggins]

14. Not even science fiction... that's pure fantasy

Science fiction has to at least have SOME science.

Squirt steam and molten corium out the bottom through the control rod ports.

Aaannd... do you think that the containment vessel would be able to hold pressure after such an event? That high radiation levels would be limited to a little water?

Yes, the design is similar to Chernobyl!

Nope. They are "similar" in the sense that both are called "reactors". The containment design ("sic" in the case of Chernobyl) are not at all similar.

Thanks goodness for the people of Japan that you're wrong.

They all have removable lids for refueling.

One is "removable" while the reactor is running and does not "contain" the core (as we saw). The other is securely bolted down and can withstand MANY times the amount of pressure. As we've clearly seen.

Where is the containment dome?

Right where it started... securely bolted to the rest of the containment vessel... safely protecting the people of Japan from a disaster that would make this one look like a walk in the park.

[Fledermaus]

16. You speak with forked tongue.

Insights from the Recent Steam Explosion Experiments in TROI

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x282704

[FBaggins]

18. Measured against your standard grasp of reality on the subject...

... that must mean I'm spot on.

Did you know that a baseball player and football player colliding head to head at full speed is really a very equal matchup?

They're both wearing hats and uniforms that "contain" their body. It's really the same design.

:rofl:

[Fledermaus]

34. BOOM!

We know the lids on Unit 1. We can look down and see the floor.

Wheres the lid for Unit 3? Where are the fuel storage tanks?

Where's the corium now?
http://wwwsoc.nii.ac.jp/aesj/publication/JNST2003/No.10/40_783-795.pdf

[FBaggins]

35. You honestly think there's a reactor there without a lid on it?

And somehow magically the radiation levels around the plant aren't through the roof (pun intended)?

[Fledermaus]

36. Where is it? Yes show me a picture of it. We can see it on Unit 1.

Unit 1 Fist explosion hydrogen gas. Remember? You told me it could not happen. Hydrogen gas build up. BOOM!
We can see the floor under the roof now. The lid is in the middle and intact.

[FBaggins]

37. There's a pile of debris sitting on top of it.

But they've measures temperature and pressure in there for a few days now... You can't hold pressure without a lid. Just as they've been reporting the temperature in the pool that you don't think is there.

You can also clearly "see" the lid on all three reactors... by the lack of intense radiation.

[Fledermaus]

38. You think so? Where's the floor?

Where's the steam coming from?

[FBaggins]

39. You don't see a pile of debris?

Are you blind?

Are you REALLY saying that you that the RPV lid is off of reactor #3?

Yes or no?

There may be some UFO nut who thinks so... but you're the only one from this planet who does. That's way out there even for you.

Can you explain why not a single thing that should happen in that event has happened?

[AndyTiedye]

2. Looks like…

:nuke:

[stockholmer]

3. it is hydrogen, if it was steam, that would mean the vessel was already breached(which it is now)or

the spent fuel rod pool was already in meltdown (which it now is).

Due to the fact that Unit 3 is also the plutonium MOX-fueled reactor, if this was steam from either scenario (carried to it conclusion), you would have already had thousands of radiation deaths, as even micronic amounts of plutonium 238, 239, 240, 241, 242, etc render you the walking dead.

This however(a massive steam explosion, dwarfing this cloud in the pic), unfortunately is a very high probability, as at least three of the units (and probably 4) now have rector vessel breaches, and spent fuel rod (there are 600,000 rods between the 6 total units, all outside any vessel containment) pools in various states of meltdown. There is pooled radioactive (10,000 times normal level) water in units 1,2,3, and 4, further evidence of vessel breach.

[ReturnoftheDjedi]

5. it could be steam if the breach occurred during the explosion

[stockholmer]

6. that's a possibility, but you would have thousands dead or near dead already from plutonium radiatio...

and probably millions set to die within a year or two and the biggest instant cover-up in history.

That said, this scenario may very well still come to pass, but the steam blast will be hundreds of time the size, if there is a floor breach.

[flamingdem]

7. Can you lay out that scenario?

How would a floor breach happen and what could cause the explosion?

What about a spark with hydrogen gas, is that a danger inside the reactors still?

[stockholmer]

9. a floor breach scenario

If 1 or more of the units has a vessel floor breach,the world will get large varying dispersement doses of radiation. The super-reactive pile of fuel pellets will congeal into a nuclear fire-fueled mass, and bore into the containment building floor, then continue boring into the earth, until it hits the water table. At this point, the water is instantly turned into a super-charged radioactive steam jet that will blow upwards with such force that it shoot through the borehole, then the building and up into the atmosphere at jet stream level.

This will be dispersed world wide, and the radiation levels will be extreme. A nuclear steam kettle, if you will.

The true nightmare is if the floor breach occurs in Unit 3 (the MOX plutonium/uranium fueled one), as not only will the force of meltdown be greater but the deadly plutonium will increase the radioactivity by exponential levels. And if any of this plutonium, even at infinitesimal levels, gets into a person, they are a dead man/woman/child walking.


as to the hydrogen, as long as the zirconium cladding of the fuel rods keeps melting down and interacting with heat, this is a possibilty again

[Fledermaus]

8. Theres no burning graphite. It used water as a moderator. Which way was the wind blowing?

Molten corium (melted core fuel) will cause a steam explosion when dropped into water. If the pressure vessel is half full of water and the upper fuel melts and drops down into the water, it will explode into steam. It will rupture the containment vessel.

[flamingdem]

11. In this scenario, without graphite

the explosion is more localized or is it also of Chernobyl proportions?

[Fledermaus]

13. Don't know for sure. But the graphite burned and helped spread the radiation. Much more smoke.

It also helped melt the fuel into a molten mass.

But from what I have been researching, when the molten fuel mass hits water there is a steam explosion.

We did experiments in the 50s. The Koreans ran some live tests using .5kg of molten fuel and dropped it into a half filled small pressure vessel. BOOM! It will shoot the control rods and some fuel out.

I'm speculating that something like that has happened. They have admitted that some of the explosions were steam explosions.

[PamW]

15. Unlikely and getting less likely

That said, this scenario may very well still come to pass, but the steam blast will be hundreds of time the size, if there is a floor breach.
===============================

Highly unlikely now that the decay power levels have dropped by over an order
of magnitude in the 2 weeks since the tsunami.

The fuel in the reactor is running out of energy needed to destroy the structures
that contain it.

PamW

[FBaggins]

17. Silly Pam

Don't you realize that fission could start back up at any moment? The fuel rods are still melting and could end up in a configuration where spontaneous fission will just light the fuse of the real thing... then BOOM!. Why... there's probably sustained subcritical fission going on in there right now just slowing ramping up to the critical level!

:sarcasm:

[Fledermaus]

19. But..but...You and your friends told us that Fukushima was an statistical impossibility.

But yet the impossible has happened.

[FBaggins]

20. And where did I or any of "my friends" say that?

You seem to live in your own imaginary world fledermaus... time to visit the real one a little more frequently.

How could someone say that something was a "statistical impossibility" when it had already happened on a newer reactor design?

What has been said is that nuclear power is "safe"... and it is.

[ReturnoftheDjedi]

27. you've downplayed everything from the get go. don't deny it.

[FBaggins]

29. I do deny it.

I haven't downplayed the things that are legitimate dangers. I have downplayed irrationally inflated claims of danger.

[Fledermaus]

30. They don't care. They don't care about anybody.

For nuclear energy, all the costs are socialized but all the profits are privatized.

All they care about is their paycheck.

[PamW]

40. it's not downplayed....

you've downplayed everything from the get go.
-------------------------

It's not downplaying when one refuses to hype and exaggerate as the
anti-nukes invariably do.

It's called being accurate.

PamW

[PamW]

23. "Statistical impossibility" is MEANINGLESS

You and your friends told us that Fukushima was an statistical impossibility
======================

Evidently you don't understand probability theory or statistics. Otherwise,
you would not have used a complete nonsensical term like "statistical impossibility".

If something is impossible, then it is impossible. One doesn't use statistics
when something is impossible.

Something can be statistically improbable, but not statistically impossible.

The accident in Japan was an improbable accident. It took a very uncommon 9.0 quake
to trigger a tsunami of sufficient magnitude to take out the plant's cooling systems.

Also, any claim I make to improbability is with regard to nuclear power plants that
meet US standards of design. The Japanese plant didn't meet US standards and contained
a serious design flaw. The Japanese put the all important diesel generators in a basement
that could be flooded by water.

When somebody does something that ill-advised, then with regard to safety, all bets are off.

Is air travel considered safe? Yes, most would say so.
However, if the flight crew dispenses with using the pre-flight checklist, and
forget to put down the flaps for takeoff and the plane crashes, does that mean we
shouldn't fly in airliners anymore. ( My best friend as a child lost her father in
such a crash in 1987).

PamW

[FBaggins]

24. Oh lordy... don't start with the air travel comparisons.

You're going to get cussed out something fierce... and the the entire thread gets deleted to clean up the mess. :)

[PamW]

26. Thanks - I had no idea.

You're going to get cussed out something fierce...
==================

Don't the denizens of DU like air travel either? Or are they rabid supporters of air
travel?

I gather some think that nuclear is evil incarnate, and any comparisons of nuclear power
to anything else is going to rile them.

PamW

[FBaggins]

28. I'm sure that they like air travel just fine.

What they (not "DUers", but "rabid anti-nuke DUers") can't abide is pointing out that you can't apply their "logic"(sic) to ANY other form of technology and get the same results.
.
Hydro power IS safe... but a massive natural disaster beyond what is contemplated could take out a dam and kills thousands upon thousands of people. THAT most certainly wouldn't be evidence that hydro power should never have been considered.

This cannot be contemplated. The fact that a nuclear power plant melts down... even in the worst of circumstances and even if not a single person dies of radiation (not a give at this point), it's PROOF that no reactors should ever have been built.

[Yo_Mama]

31. That already happened

Banqiao Dam
http://en.wikipedia.org/wiki/Banqiao_Dam

Tremendous loss of life. That too was a complicated disaster which caused cascading failures and began with a typhoon. It ended in an inland tsunami.

I wouldn't say that dams are safe, but I wouldn't say that any source of energy is safe. Some are safer than others.

Everything in life is an exercise in offsetting risks. It is unsafe to leave your house in the morning and drive to work, but we do so because the very small chance of death or significant injury is much less of a risk than the certainty of not having income. There is a very small risk that seems to show up in statistics from having detailed X-ray studies or CAT scans, so we use them when we need them to get information to avoid much larger risks.

Energy allows us to offset many very large risks (such as the risk of freezing or starving). The search has always to be for less risk. To achieve "safety" is impossible.

[PamW]

21. Extremely unlikely that there would be a criticality

Don't you realize that fission could start back up at any moment?
=====================

Evidently you don't understand that for a "criticality" there has to be
some very precise conditions. In order to get self-sustaining chain reactions,
the materials and geometry have to satisfy some very stringent conditions.

That's why the term is "critical". "Critical" means that you are on the
knife's edge about to fall off. That's why if you are in "critical" condition
in a hospital, you are in danger of dying.

Professor Downar of the Nuclear Engineering Dept at the University of Michigan
states the following courtesy of the following website for physicists:

http://www.physorg.com/news/2011-03-japan-worst-case-scenario-catastrophic-expert.html

Spent fuel, which is fuel that has already been used but still retains a level of radioactivity, is a new concern, says Thomas Downar, a professor in the Department of Nuclear Engineering and Radiological Sciences.

"The worst thing that could happen now is the fuel rods could be exposed to the air and that could be, then, down to our last barrier," Downar said. "We could not have a recriticality, or a nuclear explosion. It's physically impossible in this kind of system."


PamW

[FBaggins]

22. I think you missed the sarcasm tag.

:)

I was just giving you a taste of the nonsense I've been dealing with here.

Some believe that the periodic smoke/steam from a couple buildings are because the cores have burned through containment and are now in the water table. That's why the water in Tokyo had such dangerous concentrations of radiation... they must share the same aquifer or something.

Went round and round the other night with a lady who couldn't tell the difference between heat and temperature and insisted that fission continues to be the source of the raging heat (because spontaneous fission counts you know?). There was no way that that ongoing fission was a mere 1% of the output of an active reactor (I didn't have the heart to tell her that they hit 1% pretty quickly and are now well below even that).

[PamW]

25. Genius has limits, and stupidity is boundless.

Went round and round the other night with a lady who couldn't tell the difference between heat and temperature and insisted that fission continues to be the source of the raging heat (because spontaneous fission counts you know?).
======================================

One of the quotes that has been ascribed to the late Dr. Edward Teller is when he
asks what the difference is between genius and stupidity. The answer is that there
are limits to genius.

There was a report recently that only about 1% of the US populace has a good grasp
of science. With all the reliance we put on science and technology, one would think
that people would hold it in higher regard and learn about it.

Then there are those that think that scientists and engineers can do anything. They
are the ones that say that we should put some more money into research so that we can
get an engine whose efficiency exceeds the Carnot efficiency limit.

PamW

[Yo_Mama]

32. Pam - I hear you

Unfortunately, a lot of those people are on DU.

They talk about science, but they really hate it.

[PamW]

33. Amen to that.. Amen

They talk about science, but they really hate it.
=================

Amen to that!

They are "cherry pickers" and "fair weather friednds".
They only listen to scientists when it suits their own agendas.

If the scientist tells them about global warming, then they'll use that to bash
Republicans or the business community and call them "stupid" because they don't
listen to the scientists.

But let the scientists tell them that nuclear power is the answer, and that
renewables can't handle the load that maintains us in the style of living that
we've become accustomed to, and they want no part of what the scientist says.

PamW