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[emsnews] Japan: TEPCO predicts possible "china syndrome". - Page 21

post #201 of 242
Quote:
Originally Posted by Steelbarrage View Post

Concrete can only retain so much energy if it has a constant heat capacity.
Think of it as a bathtub with a small drain
If more water is input into the bathtub than drains, it will slowly fill up.
The drain is analogous to the natural thermal diffusivity of concrete, which will be near to the ground temperature.
Once the tub reaches near the top it will encounter the overflow drain, this is the heat gradient of the outer shell of the concrete where it will be affected by the ground in a short period of time.
If the water is still pouring in fast enough the tub will over flow.
The overflowing water is what heat energy is escaping the system.
As long as even a drop of water gets out it will be doing work.
The rates at which work is done is dependent on the difference in between energies.
105 C will boil little water very slowly but if it is 600 C then it will create lots of superheated water or steam.
The difference between the two rates are simply the quantities of heat flow.
More like a bathtub with a thousand tiny holes all up and down the sides of it. And your input amount of water is only the size of one of those holes, yet you claim all of the water will stay in the tub until it reaches a hole at the very top, at which point it will start flowing out of said top hole.

What you are saying, on a smaller scale, is that the tip of a needle held constant at 105c could heat a piece of concrete the size of a pot of water to 105c, while outside, then put a drop of water on the concrete and it would instantly turn to steam. Absolutely absurd. The needle tip itself could boil a tiny bit of water, sure, but by the time the heat is dispersed through the concrete, it wouldn't be anywhere near the 105c temperature that the source is putting out. It's like sound - the dB level right next to a speaker is much louder than the dB level 10 feet away. The full power of the sound waves is dispersed through the room. It isn't focused in one area. Similarly, the heat that the concrete slab DID give off, however slowly it would be, wouldn't be concentrated enough in a single area of the concrete to boil water - it would be dispersed along all of the surface area of the concrete, and only slightly warm any nearby water.

Here's an experiment: Heat up a cinder block with a soldering iron, and see how long it takes to boil water off of the opposite end of the cinder block. I'll give you however many months you want, but it has to be done outside. wink.gif Oh, and you've already got a one-up, since a soldering iron tip is much hotter than 105c.
post #202 of 242
Thread Starter 
I'll probably get a lot of flack for only linking to one anti-nuclear news site....I am unable to find more sources besides. Thom Hartmann talks with Kevin Kamps, Beyond Nuclear: www.beyondnuclear.org about concerns of a major environmental catastrophe at Japan’s damaged nuclear power reactor.

They’re admitting that there has been very deep melt-through at No 1, only a foot and a half left
Then its a pretty short course into the environment into the soil into the groundwater
Bear in mind this is all a computer simulation
So what kind of shenanigans are they playing with the computer modelling?
They are admitting they are very close to the final steel barrier to prevent penetration of the earth which is by definition the China Syndrome

http://enenews.com/
Quote:
(TEPCO) released December 2 the results of its internal investigation into the causes of the Fukushima I nuclear power station accident that had become the world’s largest nuclear disaster [...]

“Regarding the accident management plan that had been developed prior to the accident, the plant operator concluded that there was no problem with the plan”
TEPCO’s report said “while measures for preventing hydrogen explosions for unit 3 had been considered, equipment had not arrived in time”
TEPCO “concluded that the large noise after 6 a.m. on March 15 had been a hydrogen explosion caused by flow from the unit 3 vent (steam emissions) into unit 4″
“Strong possibility that there had been an instrument failure rather than an explosion at the unit 2 suppression pool”

Edited by aweir - 12/6/11 at 12:34pm
post #203 of 242
SgtSpike
You have to realize this is a relatively closed system.
Your bathtub analogy with a thousand holes is more accurate.
The situation is though that more heat energy is put in than lost through these holes so the bathtub will still overflow.

The cinder block analogy is terrible because it does not take into account a relatively closed system.
When you apply heat at a point it will flow out and at any surface the heat energy will be lost.
Internally the heat energy will be used to raise the internal heat energy of the block.
This raising of the internal energy will be reduced by the lower areas around it.
Since concrete diffuses heat energy so slowly though the input rate is still higher than the rate at which heat energy can reach the distal areas and dissipate.
This will result in an overall advance of heat energy through the concrete, even though it is losing some to raise the internal energy of its surroundings.
Because most of this heat is still retained within the concrete very little has had time to get to the outside edges.
This provides a favorable conduit that is still within equilibrium with the source while the immediate area surrounding it is more cool.
You will eventually have an area on the outside that is near to same temperature.

The cinderblock will need to be insulated on the side of the application of the soldering iron.
The soldering iron will create a cone of heat.
As the cone expands the distal areas are still raising the heat of concrete where the center will be very close to the soldering iron which has brought the heat capacity of that area to its max.
This will continue on until it reaches near to one of the closest surfaces.
Up until this point the external surface has played very little in affecting the heat loss.
Now though the internal heat capacity and external heat difference will affect the heat energy.
There is still a significant amount of heat built up with in the concrete already though that helps along with the original input to heat up the near surface concrete and the external surface.
This process will take a long time at low temperatures but it will eventually occur.
You may wonder about more distal areas though?
The fact that concrete is an excellent insulator will mean the diffusivity is still low but the thermal inertia within the system can account for this loss.

The overall conclusion that I am trying to make here is that you don't need the material on the reactor floor to be 600 C but it could be much closer to the 150 C or even the values reported by the water circulation within the reactor unit.
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post #204 of 242
Im lost are we all gonna die soon?
post #205 of 242
Even if the reactor material is within a foot and a half of the outer wall, IT IS NOT HOT ENOUGH, to still be molten.
There would be dramatic amounts of steam flowing from the ground. if that were the case.
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post #206 of 242
Quote:
Originally Posted by Steelbarrage View Post

Game theory proves that the Japanese government has no reason to lie or cover up the Fukushima incident.

It's statements like this that make me question anything you say. Of course governments lie and so do corporations. In the world we live in today,politicians are not so much worried about the average voter. They cater to the corporations that fund their getting elected. Even when the evidence clearly shows guilt or negligence most would go to their grave proclaiming innocence. I think most of that comes from their fear of bankruptcy from lawsuits, they never want to part with a penny no matter what they did. It's cheaper to hire attorneys and deny everything. With the greed and corruption in today's world your right more than your wrong when you assume the government and corporations are not telling the truth. You also mentioned the gulf oil spill and all the miss information. Do you really believe that the gulf had no real lasting damage and that corexit is no more dangerous than dish soap? Because that is what BP and the US government want people to believe. If they admitted their guilt they would be out of business and office.
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post #207 of 242
Quote:
As much as 45,000 liters (11,870 gallons) of highly radioactive water leaked from Japan’s crippled Fukushima nuclear station at the weekend and some may have reached the sea, Tokyo Electric Power Co. (9501) said.

The water contained 1.8 millisieverts per hour of gamma radiation and 110 millisieverts of beta radiation, Tepco said in an e-mailed statement yesterday.

As much as 300 liters leaked through the crack, Junichi Matsumoto, a general manager at the utility, told reporters in Tokyo today. The utility is still checking how much contaminated water has reached the sea and the effects on the environment, Matsumoto said.

Tepco said the leaked water contained 16,000 becquerels and 29,000 becquerels per liter of radioactive cesium 134 and 137 respectively. Those levels exceed government safety limits by 267 and 322 times, according to Bloomberg calculations.

(source: Bloomberg)
post #208 of 242
Thread Starter 
I have scoured the internet yet I can't find an answer. How hot does nuclear fuel get during a meltdown assuming there was no water to cool it? The only answer I found was 5,189 C. which is way hotter than 100C.


http://www.livescience.com/13218-nuclear-meltdown.html?+news

A partial meltdown of nuclear fuel rods has occurred in two, or perhaps three, nuclear reactors at the Fukushima Daiichi power plant in Japan. What does that mean exactly?

"A meltdown is when the uranium dioxide fuel melts. The melting temperature of uranium dioxide is 5,189 degrees Fahrenheit (2,865 degrees Celsius)," said Martin Bertadono, a nuclear engineer at Purdue University.
post #209 of 242
Aweir
I have seen the temperatures as 2200 C to 2500 C.

Jameskelsey
Talking to many petroleum geologists that come give lectures at my school, I gleaned that BP is on a massive sell off of their properties and assets.
Essentially they want to pull out of NA.
That doesn't seem like they are trying to continue on as if nothing happened.
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post #210 of 242
Quote:
Originally Posted by Steelbarrage View Post

SgtSpike
You have to realize this is a relatively closed system.
Your bathtub analogy with a thousand holes is more accurate.
The situation is though that more heat energy is put in than lost through these holes so the bathtub will still overflow.
Proof? How do you know that heat doesn't start dissipating faster than it is put in until it reaches the same temperature as the source? Especially when you have 4800 sq ft of surface area to dissipate it through?
Quote:
The cinder block analogy is terrible because it does not take into account a relatively closed system.
When you apply heat at a point it will flow out and at any surface the heat energy will be lost.
Exactly my point. The heat flows out and is dissipated throughout the object, which then dissipates it into the surrounding air (or ground, if you want to make it a "closed system").
Quote:
Internally the heat energy will be used to raise the internal heat energy of the block.
This raising of the internal energy will be reduced by the lower areas around it.
Agreed
Quote:
Since concrete diffuses heat energy so slowly though the input rate is still higher than the rate at which heat energy can reach the distal areas and dissipate.
Disagreed. If the heat reaches the edge of the concrete, it will start dissipating. And since the surface area of the heat going in is a pinprick compared to the surface area of the heat going out, the heat going out will be dispursed across a much greater area, meaning it won't be nearly as hot as the source.
Quote:
This will result in an overall advance of heat energy through the concrete, even though it is losing some to raise the internal energy of its surroundings.
Yes, to an extent. But as the concrete gets hotter and hotter, it loses that heat more and more quickly. It won't ever reach 105 C, because it'll lose the heat as quickly as it is put in long before that.
Quote:
Because most of this heat is still retained within the concrete very little has had time to get to the outside edges.
This provides a favorable conduit that is still within equilibrium with the source while the immediate area surrounding it is more cool.
You will eventually have an area on the outside that is near to same temperature.
No, you won't.
Quote:
The cinderblock will need to be insulated on the side of the application of the soldering iron.
Why? It's not insulated in the nuclear plant.
Quote:
The soldering iron will create a cone of heat.
As the cone expands the distal areas are still raising the heat of concrete where the center will be very close to the soldering iron which has brought the heat capacity of that area to its max.
Exactly - the cone expands. That's the part that you seem to be forgetting. The heat put in to the cement is dissipated across 4800 square feet of surface area. It can't possible heat the whole slab to 105c, but that seems to be what you claim. You seem to think that energy comes out of nowhere. If you put in 105C worth of heat @ 16 sq ft of area, then you can't expect more than 105C worth of heat @ 16 sq ft of area. But you seem to expect 105C worth of heat @ 4800 sq ft of area. It's not going to be 105C ANYWHERE on the cement edge because the heat is dissipated across the WHOLE cement edge.
Quote:
This will continue on until it reaches near to one of the closest surfaces.
Up until this point the external surface has played very little in affecting the heat loss.
Now though the internal heat capacity and external heat difference will affect the heat energy.
There is still a significant amount of heat built up with in the concrete already though that helps along with the original input to heat up the near surface concrete and the external surface.
But if the heat builds up, why would it suddenly be release quickly? In order to boil water, you would have to have a LARGE amount of energy/heat released from the concrete into the water at the same time, in the same place. But you say that concrete doesn't release heat quickly, or it wouldn't be able to build up heat within itself.
Quote:
This process will take a long time at low temperatures but it will eventually occur.
You may wonder about more distal areas though?
The fact that concrete is an excellent insulator will mean the diffusivity is still low but the thermal inertia within the system can account for this loss.
The overall conclusion that I am trying to make here is that you don't need the material on the reactor floor to be 600 C but it could be much closer to the 150 C or even the values reported by the water circulation within the reactor unit.
There is a temperature gradient, you've already admitted that much. Like soundwaves, the heat is dissipated and diluted as you get further from the source.

Once the heat DOES reach the edges of the concrete, it would come out at the same rate as it is input. If you want to use the bathtub example, it would overflow at the same rate that you put it in. But you seem to expect to be able to catch ALL of the input water with a straw, despite it overflowing across all edges of the bathtub. Same with the concrete - once it heats up to the "overflow" level, where the amount of energy input equals the amount of energy output, you would indeed get the same wattage of energy released from the concrete as was put in from the source. But because that wattage of energy is NOT released from just a small part of the concrete, but instead across 4800 sq ft of it, the temperature of release would be much, much lower.

100w of electricity distributed across 4 square feet of concrete is not going to come up with the same result as 100w of electricity distributed across 1000 square feet of concrete. Do you agree?

If what you are saying was true, then you could use the same amount of electricity to heat a 100 sq ft home with concrete radiant heating as a 1000 sq ft home with the same flooring. It simply isn't going to happen - the 1000 sq ft home is going to require more electricity to heat to the same temperature. And that means either more heat at a small source, or more sources with the same level of heat.
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