Exposed? Asahi: Water may not be reaching part of melted nuclear fuel from Reactor No. 2, says unnamed Tepco official

Published: February 7th, 2012 at 10:31 am ET
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Title: TEPCO struggles to cool Fukushima plant’s No. 2 reactor
Source: AJW by The Asahi Shimbun
Author: Takashi Sugimoto and Jin Nishikawa.
Date: February 07, 2012

Tokyo Electric Power Co. is taking steps to prevent a possible self-sustaining nuclear chain reaction at the crippled Fukushima No. 1 nuclear power plant. [...] 

“We expect them to address the public’s concerns by methodically explaining what could happen and how they plan to deal with it,” [Haruki Madarame, chairman of the Nuclear Safety Commission of Japan] said. [...]

TEPCO officials said the rise in temperatures was not steep enough to indicate that criticality had been reached.

[...] TEPCO has assumed a margin of error of up to 20 degrees for the thermometers [...] Therefore, a reading exceeding 80 degrees could mean an actual temperature of more than 100 degrees, compromising the reactor’s status as being in cold shutdown. [...]

“The temperature may have risen because water has not reached part of the fuel since the amount of water through the feed water system decreased and the flow of water changed,” said an official at TEPCO’s Nuclear Power and Plant Siting Division.

Read the report here

See also: Tepco: Water injections may no longer be able to properly cool down melted nuclear fuel in Reactor No. 2 -- Says criticality is not taking place (VIDEO)

Published: February 7th, 2012 at 10:31 am ET
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14 comments

Related Posts

  1. Asahi: Tepco checking if “chain of nuclear fission has occurred again in melted fuel” at Reactor No. 2 after temperature rises sharply February 6, 2012
  2. Tepco: Water injections may no longer be able to properly cool down melted nuclear fuel in Reactor No. 2 — Says criticality is not taking place (VIDEO) February 6, 2012
  3. Tepco backpedals on No. 2 water level: “Possibly” 2.8 meters of water inside reactor, had been claiming much higher — Now just “quite unlikely” fuel is exposed January 20, 2012
  4. Nikkei: Reactor No. 2 hits 78.3°C — Tepco: Melted fuel may be moving inside RPV February 11, 2012
  5. 82°C at Reactor No. 2 — Keeps rising even after injection of more water — Tepco “set to dump in boric acid” February 12, 2012

14 comments to Exposed? Asahi: Water may not be reaching part of melted nuclear fuel from Reactor No. 2, says unnamed Tepco official

  • jahdesm jahdesm

    tepcos thermometers are 200 years old stuff??? incredible!!!


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  • Gotham

    The temperature may have risen because water has not reached part of the fuel since the amount of water through the feed water system decreased and the flow of water changed.

    I guess some pipes may for frozen and sprung leaks here too. Is all this radioactive water going into the ocean?


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    • Nope, they are collecting all of this water using thimbles, and it will used to make cesium cookies.

      I would love to see a picture of 30 leaks and the amount of water coming out of these..

      Is it high pressure, high volume leaks, or just drips from low pressure water hoses?

      What is the radiation in that leaking water?


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  • Water Fails to Cool Them Down

    …Tepco says that no new nuclear chain reactions are occurring … but admits that the water may no longer be able to cool the reactor. As NHK reports:
    Attempts to cool the temperature in the No. 2 reactor of the disabled Fukushima Daiichi nuclear power plant have only partially succeeded despite the injection of more cooling water.
    The temperature in the reactor has gradually risen from about 45 degrees Celsius registered on January 27th.
    In the past 4 days, the temperature has climbed more than 20 degrees to above 70 degrees.
    The plant operator, Tokyo Electric Power Company began pumping more water into the reactor at around 1:30 AM on Monday. But at 7 AM, the temperature stood at 73.3 degrees and at 5 PM, 69.2 degrees.
    TEPCO says the rise in temperatures indicate that the flow of water in the reactor may have changed direction after plumbing work, and is no longer able to …
    http://www.zerohedge.com/contributed/fukushima-reactors-heating-again-%E2%80%A6-water-fails-cool-them-down


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  • truthsetufree truthsetufree

    Is anyone watching the live video feed. Becuase it looks like Reactor No 3 is throwing off alot of steam. Just saying or it just soming in the background.


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  • labmonkeywithagun labmonkeywithagun

    Another explaination is ass-backwards.
    Now the water is reaching a part of the corium and moderating neutron speed to cause more reactions. And being an ass backward person, shoot in the Xenon to absorb them along with boron. Still will displace the hydrogen, hey?


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    • Spectrometising

      labmonkeywithagun:….This might explain about the hydrogen. It is serious if it is hot enough to vapourise and react with steam creating a metal explosion…
      From Wikipedia….:..”Oxidation of zirconium by steam

      One disadvantage of metallic zirconium is that in the case of a loss of coolant accidents (LOCA) in a nuclear reactor, the Zr cladding rapidly reacts with water steam at high temperature. Oxidation of zirconium by water is accompanied by release of hydrogen gas. This oxidation is accelerated at high temperatures, e.g. inside a reactor core if the fuel assemblies are no longer completely covered by liquid water and insufficiently cooled.[9] Metallic zirconium is then oxidized by the protons of water to form hydrogen gas according to the following redox reaction:

      Zr + 2 H2O → ZrO2 + 2 H2 …..”
      http://en.wikipedia.org/wiki/Zirconium_alloy


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  • Spectrometising

    My reasoning is that the material slowly becomes encrusted in a deposition of complex compounds and scale. In turn, these create an insulating layer.
    At a certain point, using a saucepan of soup as an analogy, a dry deposition/scale interface forms between the soup and the saucepan forming an insulating layer.
    So now we should see increased radionuclide in the injected water taking into account a higher rate of dilution.


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    • aigeezer aigeezer

      Hi Spectro. Interesting soup analogy – thanks! I’m trying to understand the implications.

      In the case of the molten core, the insulating crust is increasing outside/around the core and it will thus increasingly prevent cooling water from affecting the core. Is that the concept?

      If that’s the model, can you make any predictions about what to expect next? For example, will the crust melt again as core temperatures increase further or will the crust increase and effectively entomb the molten core within it?…


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      • hbjon hbjon

        Molybdenum has a melting temperature that is much higher than Zirconium. If Zirconium is irradiated by transurans, you may get a high enough concentration of Molybdenum to form the hypathetical outer crust. There would be fissures in the crust to allow more volitile elements to escape, creating its own vents if you will. Molybdenum is known to be brittle and prone to fissures. You can’t ask for a better containment, if the crust of Molybdenum was thick enough.


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  • labmonkeywithagun labmonkeywithagun

    later guys, hope I’m making a point and not totally crAZY.
    I am aiming for insanity, gotta’ be easier right?


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