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  1. #101
    No darkness Cry Havoc's Avatar
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    Didn't the reactors went through a proper SCRAM? Now I don't know, and didn't seek those details.

    I agree with all you have said except I don't think these reactors pose any potential threat like Chernobyl, or Three mile island. I'm pretty certain most of this is now media hype, to sell stories and keep people tuned in.
    A SCRAM, when initiated, plunges fuel rods at a controlled, but otherwise rapid rate deep into the coolant (one of the reasons that Chernobyl exploded is that they actually dropped the control rods without controlling them, and when they hit the coolant, they were moving so quickly that they actually splashed a lot of it outside of the core, meaning they lost coolant from the SCRAM). The idea is that you completely submerge the rods, thus mitigating their ability to heat the steam that spins the turbines. A SCRAM is used to conclude nuclear power generation.

    You cannot SCRAM if you do not have available coolant. Right now, these rods have nothing to keep them cool other than the seawater that's being pump into them, but it's not enough, as they are too hot to be sufficiently cooled by ocean-temperature water.

  2. #102
    No darkness Cry Havoc's Avatar
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    Emergency Cooling Effort Failing at Japanese Reactor, Deepening Crisis

    http://www.nytimes.com/2011/03/15/wo...uclear.html?hp

    Workers were having difficulty injecting seawater into the reactor because its vents — necessary to release pressure in the containment vessel by allowing radioactive steam to escape — had stopped working properly, they said.

    The more time that passes with fuel rods uncovered by water and the pressure inside the containment vessel unvented, the greater the risk that the containment vessel will crack or explode, creating a potentially catastrophic release of radioactive material into the atmosphere — an accident that would be by far the worst to confront the nuclear power industry since the explosion of the Chernobyl nuclear power plant 25 years ago.


    You can say it's hyperbole all you want, or media frenzy, but this is a serious situation, WC. If those fuel rods stay uncovered, they are going to get hotter and hotter until something catastrophic happens.

  3. #103
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    Repugs "want to revive the site as part of a broader plan that calls for building 200 new nuclear plants by 2030."

    http://www.mcclatchydc.com/2011/03/1...ive-under.html

    =========

    Repugs, ALWAYS with their heads up their asses. There's no financing for ANY nukes, never mind 200. And of course, the US taxpayer would be the liability insurer.

  4. #104
    I play pretty, no? TeyshaBlue's Avatar
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  5. #105
    Mr. John Wayne CosmicCowboy's Avatar
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    Didn't the reactors went through a proper SCRAM? Now I don't know, and didn't seek those details.

    I agree with all you have said except I don't think these reactors pose any potential threat like Chernobyl, or Three mile island. I'm pretty certain most of this is now media hype, to sell stories and keep people tuned in.
    You are kidding, right? THREE reactors with exposed fuel rods and no way in of cooling them? Thats some bad juju, especially reactor #3 that is loaded with MOX fuel rods...it's shorter half life/hotter stuff...

  6. #106
    Pimp Marcus Bryant's Avatar
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    Since there appears to be at least one individual with some actual industry knowledge, as opposed to Google Wisdom, participating in this thread...let's say all three melt down. What is the impact locally? in Japan proper? the Korean Peninsula? China? Also, what is the impact to the US, including Hawaii & Alaska?

  7. #107
    Mr. John Wayne CosmicCowboy's Avatar
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    Since there appears to be at least one individual with some actual industry knowledge, as opposed to Google Wisdom, participating in this thread...let's say all three melt down. What is the impact locally? in Japan proper? the Korean Peninsula? China? Also, what is the impact to the US, including Hawaii & Alaska?
    Too many variables.

    The classic full meltdown is when the fuel rods go molten. Average molten fuel rods hit about 3500 degrees. At 4000+ degrees the molten MOX rods may burn right through the steel and concrete of the containment vessel...then they hit the "dirt" under the containment vessel and continue to bore/burn straight down into the earth till they hit groundwater...then the subsequent steam explosion is like a huge "Old Faithful" geyser of radioactive crap that blows back out the top into the atmosphere...

    At that point, it's a matter of how much and where. There will probably be a designated "no go" zone like Chernobyl. At the very least, even in a best case scenario and most of the radioactive junk blows out to sea and settles it's gonna create some issues with seafood and the food chain for a LONG time.

  8. #108
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    The impact matters on whether or not containment is breached. Other types of contamination depend on any type of breach and the method used to transfer material. If something doesn't explode then the impact should be well contained. Chernobyl was a core that exploded and had no type of containment.

    This is not Chernobyl.

  9. #109
    Mr. John Wayne CosmicCowboy's Avatar
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    One things for sure...if the rods have all gone molten they are burning through their containment vessels as we type. The question is do they burn all the way through before they finally expend their (now uncontrolled) energy?

  10. #110
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    I doubt it. They've already expended a lot of energy and its already been days since they shut down the reactors so they're already colder. I think a worst case scenario is pretty unlikely at this point but I obviously don't have any working knowledge as a nuclear engineer.

    I really think the biggest danger you have is from any damage to those containment vessels from the earthquake or subsequent explosions. But as long as they're OK I think they'll be able to bleed off enough heat to avoid a complete disaster but then again they're doing stupid like running out of pump fuel and letting the tanks the pumps are drawing from run dry.

  11. #111
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    the fact that Japanese technicians and politicians have not come out and say "this is nothing to worry about, noone will die" is probably a sign that lives are at risk right now.

  12. #112
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    Well no . They're not going to say that until they're absolutely out of the woods and they're not. But the chances of some real disaster are not really high at this point. It will be a long time before those reactors are completely under control.

  13. #113
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    depends what's your definition of "high"

    even a 1% chance is pretty high IMO when it comes to spreading radioactivity in the atmosphere and ocean

  14. #114
    Mr. John Wayne CosmicCowboy's Avatar
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    I doubt it. They've already expended a lot of energy and its already been days since they shut down the reactors so they're already colder. I think a worst case scenario is pretty unlikely at this point but I obviously don't have any working knowledge as a nuclear engineer.

    I really think the biggest danger you have is from any damage to those containment vessels from the earthquake or subsequent explosions. But as long as they're OK I think they'll be able to bleed off enough heat to avoid a complete disaster but then again they're doing stupid like running out of pump fuel and letting the tanks the pumps are drawing from run dry.
    The containment vessels are made out of steel and concrete. A puddle of molten fuel rods can burn right through both. It does it the same way molten lava melts right through rock...

  15. #115
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    depends what's your definition of "high"

    even a 1% chance is pretty high IMO when it comes to spreading radioactivity in the atmosphere and ocean
    Fair enough.

  16. #116
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    The containment vessels are made out of steel and concrete. A puddle of molten fuel rods can burn right through both. It does it the same way molten lava melts right through rock...
    Yeah at 4000 degrees I don't doubt it. That being said, everytime something melts more of that energy is used. I guess it really depends on how hot they are right now. My understanding is #2 has been the only one with exposed rods today but who knows for sure.

  17. #117
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    Palast weighs in, sounds like more an expert than WC :

    Tokyo Electric to Build US Nuclear Plants: The No BS Info on Japan's Disastrous Nuclear Operators


    http://www.truth-out.org/print/68457

  18. #118
    Veteran Wild Cobra's Avatar
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    A SCRAM, when initiated, plunges fuel rods at a controlled, but otherwise rapid rate deep into the coolant (one of the reasons that Chernobyl exploded is that they actually dropped the control rods without controlling them, and when they hit the coolant, they were moving so quickly that they actually splashed a lot of it outside of the core, meaning they lost coolant from the SCRAM). The idea is that you completely submerge the rods, thus mitigating their ability to heat the steam that spins the turbines. A SCRAM is used to conclude nuclear power generation.

    You cannot SCRAM if you do not have available coolant. Right now, these rods have nothing to keep them cool other than the seawater that's being pump into them, but it's not enough, as they are too hot to be sufficiently cooled by ocean-temperature water.
    The control rods still reduce the neutron emissions, therefore reduce the heat. If my understanding is correct, they can melt, but not go supercritical.

  19. #119
    Veteran Wild Cobra's Avatar
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    One things for sure...if the rods have all gone molten they are burning through their containment vessels as we type. The question is do they burn all the way through before they finally expend their (now uncontrolled) energy?
    Now I have no way of knowing this as fact, but it seems to me that they would have learned from past mistakes, and plaaced an alloy that would readily mix with any molten uranium at the bottom. As the uranium melts and mixes into a new alloy, it becomes less concentrated and produces less fission. It would be a final method of controlling the situation. If such a simple method was not implemented... then what can I say?

  20. #120
    Mr. John Wayne CosmicCowboy's Avatar
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    The control rods still reduce the neutron emissions, therefore reduce the heat. If my understanding is correct, they can melt, but not go supercritical.
    You're not getting. The worry is not going "supercritical" and having a nuclear explosion. The worry is the out of control fuel rods burning through the containment vessel and then a subsequent explosion/scattering of the fuel like an enormous "dirty bomb".

  21. #121
    Veteran Wild Cobra's Avatar
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    You're not getting. The worry is not going "supercritical" and having a nuclear explosion. The worry is the out of control fuel rods burning through the containment vessel and then a subsequent explosion/scattering of the fuel like an enormous "dirty bomb".
    No, I do get it. problem with that is it assumes the material doesn't dilute by mixing with the other materials it melts along the way.

    Once the pressure is gone there is no fluid within the heat range to cause a water explosion, which would be required to do as you imply. Now again, i do understand the possibilities. When i worked at an aluminum foundry, with had 3,000 pound molds... they held 3,000 lbs of aluminum. The process was a circular one. The aluminum was poured into a mold, several molds went in a circle. Water cooled, and were pulled out before filling again. On a rare occasion, traces of water was left in the tiny cracks that formed in the iron molds. The cooling sometimes brought the molds under 100 C. When this happened, and the molten aluminum was again poured in, a massive explosion would occur, and nearly all 3,000 lbs of molten aluminum went up in the air.

    Yes, I understand the dangers. If this occurred with nuclear material...

    Thing is, you will never see below 100C and a cavity condition for the water to form in, which are prerequisites.

  22. #122
    I am that guy RandomGuy's Avatar
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    Palast weighs in, sounds like more an expert than WC :

    Tokyo Electric to Build US Nuclear Plants: The No BS Info on Japan's Disastrous Nuclear Operators


    http://www.truth-out.org/print/68457
    Last night, I heard CNN reporters repeat the official line that the tsunami disabled the pumps needed to cool the reactors, implying that water unexpectedly got into the diesel generators that run the pumps.
    These safety backup systems are the "EDGs" in nuke-speak: Emergency Diesel Generators. That they didn't work in an emergency is like a fire department telling us they couldn't save a building because "it was on fire."...
    TEPCO and Toshiba don't know what my son learned in eighth grade science class: tsunamis follow Pacific Rim earthquakes. So, these companies are real stupid, eh? Maybe. More likely is that the diesels and related systems wouldn't have worked on a fine, dry afternoon.
    Back in the day, when we checked the emergency backup diesels in America, a mind-blowing number flunked. At the New York nuclear plant, for example, the builders swore under oath that their three diesel engines were ready for an emergency. They'd been tested. The tests were faked; the diesels run for just a short time at low speed. When the diesels were put through a real test under emergency-like conditions, the crankshaft on the first one snapped in about an hour, then the second and third. We nicknamed the diesels, "Snap, Crackle and Pop."
    In the US, we supposedly fixed our diesels after much complaining by the industry. But in Japan, no one tells TEPCO to do anything the Emperor of Electricity doesn't want to do.

    I get lots of confidential notes from nuclear industry insiders. One engineer, a big name in the field, is especially concerned that Obama waved the come-hither check to Toshiba and TEPCO to lure them to America. The US has a long history of whistleblowers willing to put themselves on the line to save the public. In our racketeering case in New York, the government only found out about the seismic test fraud because two courageous engineers, Gordon and John Daly, gave our team the do entary evidence.

    In Japan, it's simply not done. The culture does not allow the salary men, who work all their lives for one company, to drop the dime.

    Not that US law is a wondrous shield: both engineers in the New York case were fired and blacklisted by the industry. Nevertheless, the government (local, state, federal) brought civil racketeering charges against the builders. The jury didn't buy the corporation's excuses and, in the end, the plant was, thankfully, dismantled.

    Am I on some kind of xenophobic anti-Nippon crusade? No. In fact, I'm far more frightened by the American operators in the South Texas nuclear project, especially Shaw. Stone & Webster, now the Shaw nuclear division, was also the firm that conspired to fake the EDG tests in New York . (The company's other exploits have been exposed by their former consultant, John Perkins, in his book, "Confessions of an Economic Hit Man.") If the planet wants to shiver, consider this: Toshiba and Shaw have recently signed a deal to become worldwide partners in the construction of nuclear stations
    A bit of a rant, but they bring up a damned good point.

    Why were the back up generators for the nuclear plant on the edge of an ocean not made to withstand a tsunami? A bit of concrete would seem to be sufficient for these generators to withstand such an event.

  23. #123
    Veteran Wild Cobra's Avatar
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    Why were the back up generators for the nuclear plant on the edge of an ocean not made to withstand a tsunami? A bit of concrete would seem to be sufficient for these generators to withstand such an event.
    I agree. This was something that should not have been overlooked. Bet in the near future, things will be changing.

  24. #124
    e^(i*pi) + 1 = 0 MannyIsGod's Avatar
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    No, I do get it. problem with that is it assumes the material doesn't dilute by mixing with the other materials it melts along the way.

    Once the pressure is gone there is no fluid within the heat range to cause a water explosion, which would be required to do as you imply. Now again, i do understand the possibilities. When i worked at an aluminum foundry, with had 3,000 pound molds... they held 3,000 lbs of aluminum. The process was a circular one. The aluminum was poured into a mold, several molds went in a circle. Water cooled, and were pulled out before filling again. On a rare occasion, traces of water was left in the tiny cracks that formed in the iron molds. The cooling sometimes brought the molds under 100 C. When this happened, and the molten aluminum was again poured in, a massive explosion would occur, and nearly all 3,000 lbs of molten aluminum went up in the air.

    Yes, I understand the dangers. If this occurred with nuclear material...

    Thing is, you will never see below 100C and a cavity condition for the water to form in, which are prerequisites.
    The water would come from the ground should the core meltdown into the ground. It doesn't need to explode at that point, the steam itself would be radioactive.

  25. #125
    Cogito Ergo Sum LnGrrrR's Avatar
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    The classic full meltdown is when the fuel rods go molten. Average molten fuel rods hit about 3500 degrees. At 4000+ degrees the molten MOX rods may burn right through the steel and concrete of the containment vessel...then they hit the "dirt" under the containment vessel and continue to bore/burn straight down into the earth till they hit groundwater...then the subsequent steam explosion is like a huge "Old Faithful" geyser of radioactive crap that blows back out the top into the atmosphere...
    Yikes. Well THAT sounds lovely.

    At that point, it's a matter of how much and where. There will probably be a designated "no go" zone like Chernobyl. At the very least, even in a best case scenario and most of the radioactive junk blows out to sea and settles it's gonna create some issues with seafood and the food chain for a LONG time.
    More wonderfulness.

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