I wonder if those containment vessels can still hold if there is a 100% meltdown? Are they designed to hold a 100% meltdown without being breeched?
Possible reactor meltdown in Japan
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they are designed to contain the melted fuel but like all things it's a matter of time, the vessels can only contain it so long..they are built with that in mind and are designed to give you enough time to do something about it..but the big problem here is everything is wiped out, all the roads and everything that has happened makes the response time longer......it's a matter of time to see who wins the race, and right now it doesn't seem to be people
JHZR2
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Originally Posted By: d00df00d
Originally Posted By: Al
If those cores explode (thermally)...the world is History.
You know that's only half the story, right?
If we're going to worry, we need to know the odds that that will happen.
Right, odds are important, but odds are a far more complex thing to put into the consideration. Key first is to just understand what we are dealing with. Al says what is likely there... That is a lot of material.
But as I said a few pages back, whatever was in the bombs that went off over Japan was optimized to do what it did. I can't imagine that a power plant and cooling ponds are optimized for such a rate of energy release, and even in the case of meltdown, it could not propagate instantly. Im no expert, but Im thinking as a chemical engineer, as this is all chemical reactor/plant design in the final analysis.
Now could that be better/worse? That is a lot of speculation. But I can not see how the releases would be more energetic per unit time than a bomb. So then it is a question of if low and slow is better/worse than short and strong. Al/Mola/etc please correct me if my thinking is wrong.
Now, uranium boils at 3800C, Plutonium at a cooler 3200C. Iron melts at 2750C and stone and sand I'd imagine at around 2500C. While the concrete would likely self-destruct at somewhere around 1000C or lower, there would be a LOT of thermal mass, not to mention whatever water would be on top, to absorb heat before the rods could thermally explode or vaporize off into the environment. I'd think that a boric acid bomb or something could be released over the site before such things would happen.
I would think. Which would mean that the odds are VERY low for such a thing. Just my first concept. Thoughts?
Originally Posted By: Al
If those cores explode (thermally)...the world is History.
You know that's only half the story, right?
If we're going to worry, we need to know the odds that that will happen.
Right, odds are important, but odds are a far more complex thing to put into the consideration. Key first is to just understand what we are dealing with. Al says what is likely there... That is a lot of material.
But as I said a few pages back, whatever was in the bombs that went off over Japan was optimized to do what it did. I can't imagine that a power plant and cooling ponds are optimized for such a rate of energy release, and even in the case of meltdown, it could not propagate instantly. Im no expert, but Im thinking as a chemical engineer, as this is all chemical reactor/plant design in the final analysis.
Now could that be better/worse? That is a lot of speculation. But I can not see how the releases would be more energetic per unit time than a bomb. So then it is a question of if low and slow is better/worse than short and strong. Al/Mola/etc please correct me if my thinking is wrong.
Now, uranium boils at 3800C, Plutonium at a cooler 3200C. Iron melts at 2750C and stone and sand I'd imagine at around 2500C. While the concrete would likely self-destruct at somewhere around 1000C or lower, there would be a LOT of thermal mass, not to mention whatever water would be on top, to absorb heat before the rods could thermally explode or vaporize off into the environment. I'd think that a boric acid bomb or something could be released over the site before such things would happen.
I would think. Which would mean that the odds are VERY low for such a thing. Just my first concept. Thoughts?
Originally Posted By: Blaze
I wonder if those containment vessels can still hold if there is a 100% meltdown? Are they designed to hold a 100% meltdown without being breeched?
They're saying that 2 of the reactors containment vessels are already breached and leaking a steady stream of radiation from the active fuel rods. Isn't the bigger issue the spent fuel rods? There's like 20 years of spent fuel rods stored next to each reactor in cooling ponds...........or they used to be until the explosions!
I wonder if those containment vessels can still hold if there is a 100% meltdown? Are they designed to hold a 100% meltdown without being breeched?
They're saying that 2 of the reactors containment vessels are already breached and leaking a steady stream of radiation from the active fuel rods. Isn't the bigger issue the spent fuel rods? There's like 20 years of spent fuel rods stored next to each reactor in cooling ponds...........or they used to be until the explosions!
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Originally Posted By: JHZR2
But as I said a few pages back, whatever was in the bombs that went off over Japan was optimized to do what it did. I can't imagine that a power plant and cooling ponds are optimized for such a rate of energy release, and even in the case of meltdown, it could not propagate instantly.
This is essentially what I've been hearing as well, i.e. that a nuclear reactor could never release energy anywhere near as quickly as a bomb could.
But as I said a few pages back, whatever was in the bombs that went off over Japan was optimized to do what it did. I can't imagine that a power plant and cooling ponds are optimized for such a rate of energy release, and even in the case of meltdown, it could not propagate instantly.
This is essentially what I've been hearing as well, i.e. that a nuclear reactor could never release energy anywhere near as quickly as a bomb could.
Kestas
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The news reported another factor that is making this horrible incident more difficult to handle. The quake affected facility equipment to the point that workers can't rely on the sensors and gauges as showing accurate readings.
As to the radiation getting into the jet stream, I'd think much of it would get sent to the surface of the Pacific Ocean through precipitation before it reached the surface of the west coast of the US/Canada.
Originally Posted By: Blaze
I wonder if those containment vessels can still hold if there is a 100% meltdown? Are they designed to hold a 100% meltdown without being breeched?
Yes but containment cooling is assumed. That's not happening...and isn't gonna unless they are flooded and then allowed to steam off. This is new territory. Someone knows what the cosequences are by now. I am sure the calculations have been done.
I assume the reactor foundations are like 8 ft thick and on solid rock. The question though is..what happens if no cooling.
It would take about 25 gpm of water pumped into the building to stop it from melding down..but radioactive steam would result. Obviously if I can figure this out someone must be deciding which path to take.
So the question..supply 4 sump pumps or let 'er melt.??? I would be supplying the sump pumps. The world is watching whether somegoes to Lows.
I wonder if those containment vessels can still hold if there is a 100% meltdown? Are they designed to hold a 100% meltdown without being breeched?
Yes but containment cooling is assumed. That's not happening...and isn't gonna unless they are flooded and then allowed to steam off. This is new territory. Someone knows what the cosequences are by now. I am sure the calculations have been done.
I assume the reactor foundations are like 8 ft thick and on solid rock. The question though is..what happens if no cooling.
It would take about 25 gpm of water pumped into the building to stop it from melding down..but radioactive steam would result. Obviously if I can figure this out someone must be deciding which path to take.
So the question..supply 4 sump pumps or let 'er melt.??? I would be supplying the sump pumps. The world is watching whether somegoes to Lows.
JHZR2
Staff member
I'm sure. Some of that stuff can be pretty sensitive. However I wonder for things like delta T, pressure of the water flowing, etc how important it is. Right now, id think they are most concerned with mass in and mass out. Just do it!
JHZR2
Staff member
Originally Posted By: Al
It would take about 25 gpm of water pumped into the building to stop it from melding down..but radioactive steam would result. Obviously if I can figure this out someone must be deciding which path to take.
Al,
I dont quite get this. Isnt the "harm" due to radioactive dust due to the dispersion of the fissionable material? I didnt think that water/air turned radioactive itself... Is there a decent solubility of the U/Pu compounds in the steam?
It would take about 25 gpm of water pumped into the building to stop it from melding down..but radioactive steam would result. Obviously if I can figure this out someone must be deciding which path to take.
Al,
I dont quite get this. Isnt the "harm" due to radioactive dust due to the dispersion of the fissionable material? I didnt think that water/air turned radioactive itself... Is there a decent solubility of the U/Pu compounds in the steam?
The reactor that exploded in Chernobyl consisted of about 1,600 individual fuel channels, and each operational channel required a flow of 28 metric tons (28,000 liters (7,400 USgal)) of water per hour.
This Japanese design must be quite a bit different.
This Japanese design must be quite a bit different.
The U.S. NRC chairman tells Congress the NRC would recommend an evacuation area much larger than has taken place around Japan's reactors.
-Reuters
At this point, the biggest concern is the spent fuel pools. According to calculations based on how big the reactors are, and how long they've been in production, there could be as many as 600,000 spent rods on site.
If a full scale runaway takes place, you can bet the amount of radiation released will be incredible. Chernobyl will look like a joke compared to this. I'm not fear-mongering either, this is the reality of it. Most of my information comes from a former plant employee here in the US.
-Reuters
At this point, the biggest concern is the spent fuel pools. According to calculations based on how big the reactors are, and how long they've been in production, there could be as many as 600,000 spent rods on site.
If a full scale runaway takes place, you can bet the amount of radiation released will be incredible. Chernobyl will look like a joke compared to this. I'm not fear-mongering either, this is the reality of it. Most of my information comes from a former plant employee here in the US.
only 25gpm?
Originally Posted By: Cause4Alarm
only 25gpm?
25..26..whatever it takes.
only 25gpm?
25..26..whatever it takes.
A good automatic updating website for up to the minute info is reuters for those who don't know.
http://live.reuters.com/Event/Japan_earthquake2?ShowComments=0
http://live.reuters.com/Event/Japan_earthquake2?ShowComments=0
Originally Posted By: dakota99
At this point, the biggest concern is the spent fuel pools.
Great design, right? Store the spent fuel rods above the reactors in the same building...
With the long history of the Japanese government and TEPCO lying, it would be futile to trust anything they are publicly saying.
http://www.reuters.com/article/2011/03/15/us-japan-quake-engineer-idUSTRE72E9H420110315
At this point, the biggest concern is the spent fuel pools.
Great design, right? Store the spent fuel rods above the reactors in the same building...
With the long history of the Japanese government and TEPCO lying, it would be futile to trust anything they are publicly saying.
http://www.reuters.com/article/2011/03/15/us-japan-quake-engineer-idUSTRE72E9H420110315
wow things are going south very very quickly now
In nearly every disaster accident etc there is usually someone who warns of the possibility, they seldom are heard. We should limit the discussion to the now, as the past is kind of moot in light of the impending disaster today...
Thanks dakota99 for the live update feed..
Now back to the regularly scheduled program....
Thanks dakota99 for the live update feed..
Now back to the regularly scheduled program....
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The situation is worse than the Japanese govt says (not much of a surprise):
From Jake Tapper's Twitter page:
WH won't acknowledge it, but US is stating: those who listen only to the advice of the Japanese govt are at greater risk of life/health.
From Jake Tapper's Twitter page:
WH won't acknowledge it, but US is stating: those who listen only to the advice of the Japanese govt are at greater risk of life/health.
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