Mainichi: Melted nuclear fuel seems to be leaking out from reactor buildings

Published: November 14th, 2011 at 6:28 am ET


Gov’t aims for ‘cold shutdown’ of Fukushima reactors, but bemoans lack of data, Mainichi, Nov. 14, 2011 [Emphasis Added]:

The government and Tokyo Electric Power Co. (TEPCO) are trying to achieve a stable condition called a “cold shutdown” of crippled reactors at the Fukushima No. 1 Nuclear Power Plant by the end of this year, but they have yet to come to grips with exactly what is happening inside the reactors crippled by the March 11 earthquake and ensuing tsunami. […]

At the No. 1, 2 and 3 reactors, melted nuclear fuel seems to be penetrating the pressure vessels and even leaking out from the reactor buildings. […]

Published: November 14th, 2011 at 6:28 am ET


Related Posts

  1. Mainichi: “It remains unclear where the melted fuel is situated” — “Temperatures of the pressure vessels alone are far from convincing” September 21, 2011
  2. Mainichi: “The melted nuclear fuel is sinking toward water under the ground” June 27, 2011
  3. Mainichi: Location of melted fuel unclear — Why test for xenon when neutron detectors can directly indicate criticality? November 3, 2011
  4. Yomiuri: Unknown how much nuclear fuel has melted through Fukushima reactors and ‘dispersed’ — Questionable to assess that as nearly a ‘cold shutdown’ November 19, 2011
  5. Japan Times: Nuclear fuel is escaping from holes and cracks — Years before leaking stops? September 12, 2011

38 comments to Mainichi: Melted nuclear fuel seems to be leaking out from reactor buildings

  • ben ben

    At the No. 1, 2 and 3 reactors, melted nuclear fuel seems to be penetrating the pressure vessels and even leaking out from the reactor buildings.

    Did this ever happen before?
    (i mean the fuel going out of pressure vessel)

    • oscar419

      Ben, I do not think mankind has ever had reactor cores run away from home and their own thing. I am pretty sure this accident is what Lewis and Clark would consider “uncharted territory”.

      I think there is much hypothesis about what is going to happen from a variety of people. I however do not think anyone knows for sure how this will play out or the final resolution to the problem at hand.

      There is only one way to find out what is going to happen and that is to move through this step by careful step with an intelligently laid out plan, something I think we are yet to see.

      • oscar419

        grammar good no early to much gimmie coffee..please

      • ben ben


        what is the temperature of melted material, is it known?
        Could this material make a hole in pressure vessel?
        What is pressure vessel made of?

        • BreadAndButter BreadAndButter

          Hi ben, I’m not sure if your questions are serious, bur anyway:
          Yes, the material (molten fuel) has indeed burnt a hole in the pressure vessel, which is made of steel.
          That’s why they say it is “leaking”.

          • ben ben

            My questions are serious, look i ask,
            hopefully some physics explanation will be provided.

            Thanks, regards.

            • BreadAndButter BreadAndButter

              Hi ben, sorry, I didn’t mean to be impolite. From what I remember, the fuel melts through the steel vessel at around 2700°C.
              The probelem with the fuku type rectors is that they have holes in the bottom of the vessel to allow the insertion of the control rods to stop the chain reaction.
              Usually, these control rods fall into the vessel from above , but at this type of reactor we have in fuku they are inserted from below.

              That means that there are already holes in the bottom of the vessel, which makes it even easier for the fuel to melt / flow through.
              It has been largely discussed here at enenews a while ago, you will find lots of info if you browse the older headlines!

              viel Spass 🙂

              • ben ben

                BreadAndButter, thanks.

                i have a question: is the data from next link showing the temperature of inside of pressure vessel?


                This is what it says now:
                Unit 1-> Last value: A: 37.9 ° C
                Unit 2-> Last value: A: 66.1 ° C
                Unit 3-> Last value: A: 58.4 ° C

                Also, anyone knows what was the maximum temperature measured in last 8 months, since 311?

                • tomb1

                  I don’t remember exactly, but afaik the temperatures reached about 300°C. But they always measure the steam or water temperature, never the fuel temperature directly.

                  The fact that we saw H2-explosions underlines that the fuel was/is molten. The molten fuel vaporizes the rods (zirkonium alloy) which produces H2 in large amounts.

                  There is IMO simply no chance that the vessels are not broken. We can only hope that the concrete floors/walls surrounding the vessels can withstand the fuel.

                  To be honest, the chances are low. I have read studies where this situation has been tested. Hot fuel melts through several meters of specialized concrete within hours.

                  Tepco speaks of a “cold shutdown” and the temperatures you cite seem to underline this. The temps may be correct. In my opinion they are low because the fuel is gone, not because fission has stopped. We still have new fission products in the air.

                • BreadAndButter BreadAndButter

                  Hi ben,
                  yes, those numbers show the temp. inside the vessel.
                  Two things are good to know:
                  1.) is a private website – their admin uses data from Tepco press releases etc.
                  2.) the temperature in the vessel is so low because
                  a) the vessels are open / broken and more or less “open air” and
                  b) the molten fuel is moving downwards, eating its way through the floor, while the temp. sensor is at the upper rim of the vessel. That means the distance between fuel and sensor is growing…. Tepco keeps saying the temperatures are below 100° and that’s a good sign (“cold shutdown”). They DON’T say though that the temperatures are lowering because the hot fuel is moving away from the sensors…

                  • Arizonan Arizonan

                    tom1 and B&B: yes, this was my exact reaction back in August, when we knew the reactors had left their ‘homes’ and were traveling, but the temp sensors were still ‘at home.’ When they annoiunced they were finally stable and in cold shut down I sent several emails to the IAEA headquarters asking them how they knew this, or why they thought the reactors were not just too far from the sensors to be very hot, but i never received a reply. They have no way to know where those reactors are right now. Clearly the temps would not be so low if the criticalities we have been seeing lately were anywhere close to the temp sensors. Nuclear chain reactions produce heat. Thanks to you both for confirming what I have been thinking a long time! I still read enenews everyday, but haven’t commented in a while. This is the best place on the web for balanced info on Fuku.

              • Au Au

                B&B, sweet response! There are so many new people, everyday, that click onto enenews, who are on a steep learning curve about “the situation” and are gathering information and your response explaining it so clearly and nicely was great and will be appreciated by many people from all over the world.

              • Believe they are ‘Stainless steel’ 6″ to 8″ thick !

    • strAtum5


      “Did this ever happen before? (i mean the fuel going out of pressure vessel)”

      Yes. At Chernobyl about 140 tons of nuclear fuel melted through the pressure vessel into the chambers underneath the reactor.

  • tomb1

    off-topic: I found a video taken while Tepco was sampling dust in R3 building. I see things that could well be UO2/MOX fuel pellets all over the debris.

    My theory is that they were blown out of the SFP with the explosion.


  • goathead goathead

    I have to laugh! “nuclear fuel seems to be penetrating the pressure vessels and even leaking out from the reactor buildings” Isn’t it that the fuel is penetrating all the pressure vessels from the outside??? It’s already obviously escaped from a number of them!!!
    How much longer can this crap go on for????

  • arclight arclight

    from the article

    “TEPCO and the government’s Nuclear and Industrial Safety Agency (NISA) eventually concluded that it was not criticality but “spontaneous fission,” revealing the very fact that they were not able to come to grips with the situation inside the reactor accurately.”

    so they are saying “spontaneous fission”,,, ok wheres the spectrographic results of gases to prove that??

    “TEPCO and the government’s Nuclear and Industrial Safety Agency (NISA) eventually concluded that it was not criticality but “spontaneous fission,” revealing the very fact that they were not able to come to grips with the situation inside the reactor accurately. TEPCO plans to start operating gas control systems at the No. 1 and No. 3 reactors by the end of this year to step up its efforts to monitor radioactive substances at each nuclear reactor.”

    “Criticality can be achieved by using metallic uranium or plutonium or by mixing compounds or liquid solutions of these elements.”

    “The heat released by the nuclear reaction will typically cause the fissile material to expand, so that the nuclear reaction becomes subcritical again within a few seconds.”
    “The elements most susceptible to spontaneous fission are the artificially-produced high-atomic-number actinide elements, such as mendelevium and lawrencium, and the trans-actinide elements, such as rutherfordium.”

    • dosdos dosdos

      All they need to do is insert a wire into the reactor and connect it to a simple monitor to test for neutron release, which would verify criticality. The problem is that they don’t want to test for it. If they found neutron activity, they would have their whole PR spin deflated.

  • kintaman kintaman

    I wish the press would stop using the term “crippled” and instead use “completely destroyed”.

  • What we have is a RAGING OUT OF CONTROL NUCLEAR FIRE, IN at least THREE and possibly SIX nuclear reactors.

    This out of control radioactive FIRE has SPREAD OUT OF CONTAINMENT, and is now outside of the reactor vessel.

    Since this has never happened before, it is anyone’s guess what happens next.

    At Chernobyl, they dumped boron and the melted fuel mixed with huge amounts of sand, forming a kind of glassy substance, which melted down through several floors underneath the reactor.

    The boron and sand slowed down the reaction in the melted material, and as it melted downwards, it slowed and cooled, forming massive radioactive pools, piles and streams.

    At Fukushima, they are doing little or nothing to stop the out of control fire, little or nothing to dilute the radioactive material coming out of the reactor, and little or nothing to prevent the CHINA SYNDROME.

    At Chernobyl, they ordered hundreds of thousands of people to cleanup the mess, and dug a huge tunnel underneath the reactor, to fill it with refrigerated concrete, in order to prevent the melted fuel from reaching groundwater and causing a second, much larger explosion, which they estimated would KILL EVERYONE ON THE PLANET.

    At Fukushima, they are doing NOTHING by comparison, for up to SIX TIMES the melted radioactive fuel and up to 6000 tons of spent nuclear material around the plant, that could go up in a groundwater/melted fuel explosion…

    This is potentially a global life extinction event, and the government/Tepco plus the nuclear industry watchdog agencies are ‘massaging’ the news to make it look like they it under control and near shutdown.

    This is beyond criminal in my opinion.

    • Why are they doing little or nothing?:

      1. They do want to kill us all
      2. It’s beyond human knowledge
      3. They know it’s already too late

      Number 1. doesn’t make sense to me because I think even the right-wing dumbo-types (except for Anne Coulter) know what the real effects are. Or, I could be wrong on this. They really are that dumb. Either that, or they’ve built an articifical planet or ship somewhere and hope to escape into orbit, maybe beyond. They might have shelters hidden in granite caves deep in the mountains, but how long can one live like that, without seeing the sun or breathing what’s left of the ‘fresh’ air?

      Number 2. makes sense too. We’ve all heard “there’s nothing they can do” or “bury it in concrete”, or “it’s not in the manual” or “beyond design specs” and so on. That means they’re down to only mitigation as the final result, not solution or fixing it completely.

      Number 3 relates more to measurements, the number and type of isotopes and their effects on the human body and genome (an organism’s complete set of genetic material), even at low levels, and how isotopes interact with each other and other substances, and what other isotopes each one breaks down into and so on, i.e. scientific knowledge. Neither Busby nor Gundersen are saying it’s the end of life on the planet. But, they may not be ‘saying’ it. We know what ‘it’ is. By triangulation, deduction, and induction I think the result comes out much worse than what any one spokesperson is saying:

      Would make a great exam question:

      Explain how the Fukushima disaster will NOT cause the end of all life on planet Earth.

      Called a proof by contradiction, or reductio ad absurdum I think we’ll end up proving the opposite assertion without too much difficulty.

      • byron byron

        Good exam question pu239, but maybe better would be: Given that single celled life and a few smaller organisms will continue to survive, explain how the Fukushima disaster and subsequent disasters from rising sea levels knocking out most nuclear facilities built near sea level, leaks from plants operating well past designed lifetimes (constructed at lowest bid by workers who only wanted to be paid at the time) and their pools, plus weapons degrading — explain when you calculate the last human on earth will die. Factor in food supply, war, mutations, disease and any other factors you deem significant.