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Japan: Temperature remains high at damaged reactor(despite injection of more water)
NHK ^ | 02/07/12

Posted on 02/07/2012 5:36:50 AM PST by TigerLikesRooster

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1 posted on 02/07/2012 5:36:57 AM PST by TigerLikesRooster
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To: TigerLikesRooster; sushiman; Ronin; AmericanInTokyo; gaijin; struggle; DTogo; GATOR NAVY; Iris7; ...

P!


2 posted on 02/07/2012 5:37:37 AM PST by TigerLikesRooster (The way to crush the bourgeois is to grind them between the millstones of taxation and inflation)
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To: TigerLikesRooster
So, you have a bunch of fissionable material sitting there fissioning away, and no longer contained within its stainless steel fuel housings ~ at a low rate of course ~ but it's still fissioning.

You take tons of water, with the requisite inclusion of some Deuterium and a small amount of Tritum, and you pump it into this mass in an attempt to cool it, and you get a surprising increase in temperature!

Is this a joke?

That's basically what you do in a few milliseconds in your typical friendly neighborhood hydrogen bomb.

3 posted on 02/07/2012 5:52:24 AM PST by muawiyah
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To: muawiyah
That's basically what you do in a few milliseconds in your typical friendly neighborhood hydrogen bomb.

It's more of a joke when a non-physicist tries to explain how something like a thermonuclear devices works.

4 posted on 02/07/2012 5:58:56 AM PST by chimera
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To: chimera
So, you explain this one smart guy.

The general outline of the fission-fusion bomb has been out there for quite a long time. The details may be missing, but we currently have SEVERAL nations with sufficient knowledge of that process to have made successful bombs.

BTW, it's an ENGINEERING PROBLEM. Most of the physics was worked out and published back in the 1930s.

5 posted on 02/07/2012 6:02:00 AM PST by muawiyah
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To: muawiyah
The general outline of the fission-fusion bomb has been out there for quite a long time.

Modern weapons use a three-stage fission-fusion-fission process.

BTW, it's an ENGINEERING PROBLEM. Most of the physics was worked out and published back in the 1930s.

No, the physics of the "classical Super" were suggested by Teller and others during the Manhattan Project. The 1930s was basic research into the fission process, measuring cross-sections, etc. There was insufficient data on cross-sections to suggest that even a fission weapon was possible until the early 1940s.

What makes modern thermonuclear weapons possible is the concept of radiation implosion. Teller signed off on the first definitive study of the physics of this process, also known as the Teller-Ulam method, in the LAMS-1230 report of April, 1951. It took about a year to implement, but even Ivy Mike in Nov. 1952 was still a kind of physics test since it used liquid deuterium instead of the lithium deuteride which forms the "fuel" in contemporary staged thermonuclear weapons.

6 posted on 02/07/2012 6:48:46 AM PST by chimera
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To: chimera
There were still some concerns about the possibility of a runaway fission process somehow igniting everything on Earth ~ right down to the day they set off a fission bomb in New Mexico.

But those were uninformed opinions ~ the physicists had long known the probability of that was very small so they forged ahead with the engineering part.

What you have here is something UNEXPECTED by the current hot-nukes guys. All they're doing is running a large volume of water (into a nuclear pile) and doing that repeatedly! Or, maybe they're just dumping it into the ocean. Do you actually know what these yahoos are doing?

Has anyone done it quite this way before? Isn't there a reason nuclear power plants use fuel that's packed in discrete amounts in precisely measured containers?

7 posted on 02/07/2012 7:05:06 AM PST by muawiyah
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To: muawiyah
*sigh*

Where to begin? Well, anyway, here goes...

So, you have a bunch of fissionable material ...

The fuel in a LWR is not "fissionable", it is fissile. It undergoes fission by absorption of a thermal neutron. Fissionable material is typically classified as something that requires a high-energy neutron to induce fission.

...sitting there fissioning away,

Other than spontaneous fission and perhaps a very small amount of subcritical neutron multiplication, there is no credible evidence of ongoing criticality in any of these reactors.

... and no longer contained within its stainless steel fuel housings

Fuel in a LWR is not contained in stainless steel. The cladding of fuel rods is zircalloy.

~ at a low rate of course ~ but it's still fissioning.

See comment above.

You take tons of water, with the requisite inclusion of some Deuterium and a small amount of Tritum, and you pump it into this mass in an attempt to cool it, and you get a surprising increase in temperature!

Far too little deuterium and tritium and in far too dilute a form to be significant for any fusion-type reactions. You need a plutonium trigger fission bomb to have sufficient energy to initiate any kind of fusion reaction. Try as you might, you are not going to get a fission detonation from any kind of LWR core, no matter how badly you damage it.

That's basically what you do in a few milliseconds in your typical friendly neighborhood hydrogen bomb.

Silly descriptors (friendly neighborhood) aside, you need far more to make a thermonuclear explosion than just bringing together uranium, plutonium, deuterium, and tritium. And the reactions in a thermonuclear detonation occur on a time scale of nanoseconds, not milliseconds. If it were milliseconds, there would be a yield comparable to chemical explosives. It is the release of a lot of energy over a very short time scale that makes for a big bang.

The first thing you need is a plutonium fission bomb. You don't have that in a LWR. Plutonium is preferred (weapons-grade, not reactor fuel grade, there is a BIG difference) because it has a higher reproduction factor than uranium. You need specially-designed tampers and "pushers", you need specially-machined radiation channels for directing the energy from the fission weapon (primary x-rays), you need a significant quantity of thermonuclear fuel, either liquid deuterium (as in Ivy Mike) or lithium deuteride. You need a pure plutonium (again, weapons-grade, not reactor fuel grade) embedded in the thermonuclear fuel. Happenstance in a damaged LWR core isn't going to produce these things, and certainly not in the form needed to initiate any kind of significant thermonuclear activity.

8 posted on 02/07/2012 7:11:17 AM PST by chimera
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To: chimera

Thank you for sharing your knowledge. Would you please sum up the risks and options for recovering a safe state in these damaged reactors?


9 posted on 02/07/2012 7:18:54 AM PST by loungitude (The truth hurts.)
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To: chimera
So, there's the answer ~ there is no heat increase!

I love it ~ you did the perfect job on deriving the correct answer (from the perspective of the hot nukes school of thought).

I'm sure the fella's at Fukushima are going to be so happy to hear it's just their imagination.

So, regarding the "zircalloy" containers ~ when they're all busted up and this stuff is just lying about being fissile, why are you pouring water on it? Like I asked, did anybody ever try this trick out before?

10 posted on 02/07/2012 7:21:18 AM PST by muawiyah
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To: muawiyah
Do you actually know what these yahoos are doing?

Yes. And they are not yahoos. They are good people doing the best they can in a difficult situation in a land that was devastated by a natural disaster. They are doing what the article said, using light water to remove heat from a material that still has a decay heat load.

And THAT IS ALL we are dealing with here. Decay heat. The materials generating the decay heat are in a geometry that is not precisely known. That makes heat transfer a difficult proposition, and modeling of the heat transfer process even more difficult. As to the temperature rise, it is explainable with much simpler and more probable mechanisms than fusion reactions. My guess (speculation, which is something generally frowned upon, but since you asked, I'll give it an honest try) is that something shifted in the cooling mass, a heat removal pathway that was previously open because blocked by debris, or perhaps vapor pressure built up enough to prevent coolant flow through an area previously receiving coolant. You see this happen all the time in other, more familiar examples. Just yesterday evening the logs in our fireplace shifted positions a little as they burned down, causing a slight increase in the radiant heat outflow. Until someone can get a visual inspection of the damaged cores, we won't known precisely what the geometry of the materials really is.

11 posted on 02/07/2012 7:21:52 AM PST by chimera
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To: muawiyah
So, there's the answer ~ there is no heat increase!

No, I never said that. I very patiently explained the physics of why there was no thermonuclear reaction occurring, which is what you suggested as a heat source.

12 posted on 02/07/2012 7:24:35 AM PST by chimera
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To: muawiyah
So, regarding the "zircalloy" containers ~ when they're all busted up and this stuff is just lying about being fissile, why are you pouring water on it? Like I asked, did anybody ever try this trick out before?

Sure, it was done after the damage to the TMI-2 core. You need more than randomly distributed fissile material and light water to initiate a fission reaction (other than spontaneous fission, which you're going to get anyway). Read up on reactor theory and the criticality equation and get back to us.

The light water is being used for heat transfer. The goal is to remove the decay heat from the materials in order to develop a plan for, first, inspecting the damaged systems, and, second, to come up with a way of recovering the materials in a way that will allow either restoration or decommissioning of the facility (TBD).

13 posted on 02/07/2012 7:29:22 AM PST by chimera
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To: chimera
No, not really ~ I was looking more at a electro-weak force explanation ~ and, in line with that you came up with the burning log ~ which is not quite there, but we're on the track.

I have no fear that any more radionuclides are going to be expelled than there ever were ~ that part of the science is certainly settled, eh! It ain't gonna' blow up, but the fellows running the show (presumably all highly trained physicists and atomic power plant engineers and designers) said the heat increase wasn't explainable.

14 posted on 02/07/2012 7:36:55 AM PST by muawiyah
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To: loungitude
Thank you for sharing your knowledge. Would you please sum up the risks and options for recovering a safe state in these damaged reactors?

Thank you. It will be a long process. The methodology is pretty well known. It will have to be implemented slowly. I am very confident the necessary operations can be conducted with essentially no risk to the general public. I am reasonably confident the people doing the work will be adequately protected, although their risk will be higher than the public due to proximity and handling of the damaged materials.

The first steps will be a visual inspection of the damaged cores to see precisely what we are dealing with. The experience we had with the TMI-2 core damage gives us a pretty good experience base as to what to expect from damaged LWR fuel (which is different than the Chornobil core). If any of it got out of the pressure vessel (if it did it likely exited through the instrument tube penetrations at the bottom of the vessel) then there will have to be a process implemented to remove that material from the containment structure.

Long-term, I don't know. It will depend on the extent of the damage. If the pressure vessels were significantly damaged, there is probably no other option than dismantling the facility. That does not mean the site could not be re-used for a power plant, but the existing structures would have to be removed.

15 posted on 02/07/2012 7:42:01 AM PST by chimera
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To: chimera

Thank you.


16 posted on 02/07/2012 7:54:27 AM PST by loungitude (The truth hurts.)
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To: muawiyah
No, not really ~ I was looking more at a electro-weak force explanation ~ and, in line with that you came up with the burning log ~ which is not quite there, but we're on the track.

The electroweak interaction is a unification between the electromagnetic and weak nuclear forces. This unification does not occur until particle interaction energies are in the range of 100 GeV, the so-called unification energy. This energy is generally not available in natural reactions except just after the Big Bang. You can get it in high energy particle accelerators, but not fission or fusion reactions. Uranium or plutonium fission releases total energy in the range of 200 MeV (MeV, not GeV). Common fusion reactions (D-D, or D-T) release energies in the range of 25 MeV per reaction. Nowhere near those needed for electroweak interactions to occur.

I have no fear that any more radionuclides are going to be expelled than there ever were ~ that part of the science is certainly settled, eh! It ain't gonna' blow up, but the fellows running the show (presumably all highly trained physicists and atomic power plant engineers and designers) said the heat increase wasn't explainable.

I think it is explainable using convention heat transfer theory, as I noted previously.

17 posted on 02/07/2012 7:57:16 AM PST by chimera
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To: chimera
Atom by atom, butt up against other atoms, and examining probabilities, there are windows of opportunity that've been known since the early 1930s.

Certainly some of the red-hot radioactive waste with short half-lives has to be doing something.

A poster up the line noted that when the Japanese point to a problem they're probably trying to hide a worse problem. No doubt we will all find out what that is over the next few months.

18 posted on 02/07/2012 8:10:22 AM PST by muawiyah
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To: muawiyah
...but the fellows running the show (presumably all highly trained physicists and atomic power plant engineers and designers) said the heat increase wasn't explainable.

I think maybe what they were saying was that they were not sure of what was causing it, or even certain it was occurring. Remember that they said they had three "thermometers" (really thermocouples) monitoring the temperature inside the pressure vessel, one showed an increase, the others didn't. That raises the question of an instrumentation problem with the one thermocouple. If it was a legitimate reading, the mechanism for the increase could be any number of things that are explainable by conventional heat transfer effects, things like blocked flow, buildup of vapor (which can inhibit conductive heat transfer), shifting of the heat-generating mass, deposition of insulating materials (debris) from the coolant flow, etc.

19 posted on 02/07/2012 8:14:15 AM PST by chimera
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To: chimera

We all must admit it’s going to be very difficult to get someone to go in there and check eh!


20 posted on 02/07/2012 8:16:50 AM PST by muawiyah
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