Report: If fuel melted through reactor, it would react with concrete floor of primary containment — Could add significantly to total radiation release

Published: May 23rd, 2011 at 6:50 am ET


Decay heat in Fukushima reactors, Union of Concerned Scientists, May 22, 2011:

As we noted last week, the Tokyo Electric Power Company (TEPCO) announced it believes the fuel in Fukushima Daiichi reactor 1—and possibly reactors 2 and 3—has melted and is sitting in a lump at the bottom of the reactor vessel. But it believes that workers have been able to keep the lump cool enough that it has not melted through the bottom of the reactor.

Such a melt-through is a concern since it would mean that highly radioactive gases released from the melting fuel would be released into the primary containment. Moreover, the molten fuel mass would then react with the concrete floor of the primary containment and create additional radioactive gases. If these are released to the atmosphere, either through venting or a leak in the containment (which could be caused by the molten fuel), it could add significantly to the total radiation released by the accident. […]

Published: May 23rd, 2011 at 6:50 am ET


Related Posts

  1. *NEW Dec. 1 Yomiuri* Gov’t Study: Reactor pressure vessel may be “tilted” after corium melted through concrete floor up to 200 cm deep November 30, 2011
  2. NHK: “This is a very severe accident” — Nuclear fuel at Reactor No. 1 may have melted through 65 cm of concrete… Only 37 cm at thinnest point (PHOTOS) November 30, 2011
  3. AUDIO: US gov’t experts think melted fuel rods landed in water under Reactor No. 2, causing STEAM explosion — Pressure dropped dramatically at same time — Clear indications primary containment lost March 2, 2012
  4. Study? No temperature readings for concrete floor — Outcome based on Tepco “projections” of decay heat & uses computer model from Westinghouse November 30, 2011
  5. Gov’t: Fuel melted “much deeper” into concrete at Fukushima reactor than revealed — Triple the depth of original estimate — Tepco: “Impossible for us to evaluate potential impact” August 8, 2014

15 comments to Report: If fuel melted through reactor, it would react with concrete floor of primary containment — Could add significantly to total radiation release

  • mark V

    And the blame game continues, why not, when this is the only thing they are good at.

  • U235P239

    Did they not announce just last week, that at least one of the reactors had a hole in the RPV, where the molten fuel had burnt through ?
    I think it’s safe to assume that all three reactors have completely melted down now and Tepco have no idea what they’re doing.

  • anne

    “The atmosphere above the epicenter of the March 11 earthquake in Japan underwent unusual changes in the days leading up to the disaster, according to preliminary data.”

    • fuckyoushima

      can haarp ‘increase the concentration of electrons in the ionosphere’?

      • anne

        Did HAARP ‘increase the concentration of electrons in the ionosphere’ over Japan. The following article explains how that may have happened.

        What is HAARP & did it cause the Japan Earthquake?

        “Essentially a transition between the atmosphere and themagnetosphere, the ionosphere is where the atmosphere is thin enough that the sun’s x-rays and UV rays can reach it, but thick enough that there are still enough molecules present to absorb those rays. Consequently, the ionosphere consists of a rapid increase in density of free electrons, beginning at ~70 km, reaching a peak at ~300 km, and then falling off again as the atmosphere disappears entirely by ~1000 km….

        “By looking at the accompanying HAARP spectrum chart above you can see when the 9.0 magnitude earthquake struck – red line drawn vertically – and what was happening before and after the earthquake. What you can also see is a constant ULF frequency of 2.5 Hz being recorded by the magnetometer. The ULF 2.5 Hz frequency is evidence of an induced earthquake. The chart recorded this constant before, during and after the 9.0 magnitude earthquake struck. On March 11, 2011 the 2.5 Hz ULF frequency was being emitted and recorded from 0:00 hours to about 10:00 hours – or for 10 hours. We know for a fact that the Japan earthquake lasted only a few minutes so why was the earthquake signature frequency (2.5 Hz) being recorded for 10 hours on the morning of March 11, 2011? Because a HAARP phased array antenna system was broadcasting (transmitting) the 2.5Hz ULF frequency and it triggered the Japan earthquake and ensuing tsunami.
        “If you go to HAARP’s official website you can see for yourself that the 2.5 Hz ULF frequency wasn’t only being broadcated for 10 hours, it was constantly being broadcasted for 2 days prior to the earthquake. Broadcasting began on March 8, 2011, just before midnight as you can see on HAARP’s website page – Click on the Next Day link to see that the earthquake inducing 2.5 Hz ULF frequency was being broadcasted for the entire days of March 9, 2011 and March 10, 2011. Even though the signature frequency of an earthquake was shown throughout March 9 and March 10 there were no constant earthquakes occurring off the east coast of Japan.
        “What is the significance of a 2.5 Hz ULF broadcast? The natural resonance of an earthquake is 2.5 Hz. Scientists working for the United States military discovered this using the phased array antennas at the HAARP facility in Alaska. HAARP’s own charts suggests that earthquakes occurred constantly for 3 days. We know for a fact that they haven’t.

        “The HAARP magnetometer data provides proof that the Japan earthquake was not a naturally occurring quake – it was triggered. “

  • anne

    Fukushima reactor had meltdown 3.5 hours after cooling system collapsed: U.S. researcher

  • @anne – I hear you – shame that millions don’t. Maybe check out Dr.John Coleman’s “Committee of 300” for an accessible understanding of who’s running the planet to destruction?

    I’m beginning to feel that the news coming out of Japan is rapidly increasing in weirdness. For instance, in this latest article they state:-

    “Such a melt-through is a concern since it would mean that highly radioactive gases released from the melting fuel would be released into the primary containment.”

    Yet all video, cams & stills have shown us ALL since very early on in this appalling disaster that THERE IS NO ‘Primary containment’ LEFT for reactors 1,3 & 4 and #2 could be just an illusion of integrity!

    How much longer will it be until the entire world erupts in disgust at this attempt at “Reality TV for the brain dead”? Perhaps it has something to do with O’Bomba’s diktat to ‘save TEPCO shares at any cost’?

    Thanks to excellent sites like this one, at least the general public has a useful resource in its hands, if only the gp can get off its collective posterior long enough to pay attention amidst its flouride+aspartame+TV generated fog!

    Finally, why do I have George Carlin (or was it Bill Hicks?) forever echoing his immortal words through my head?

    “Go back to sleep America, your gubbermint is in control again!”

  • Anna

    We need Berndt Mueller!
    Here is a post he made on April 21, 2011
    I hope he does not mind that I am bumping up his post:

    Bernd Mueller
    April 21, 2011 at 5:44 am · Reply


    Due to the catastrophic situation in Fukushima we tried to help solving the problem with our modest possibilities and constructed an exhausting and filter machine, which could prevent the radioactive particles from spreading around the country.

    As You can see below, we are a small german company constructing and dealing since 15 years with industrial environmental protection products.
    We truly believe, that there is a god chance to help the japanese authorities to prevent the area from radioactive contamination.
    Radioactive particles are still ascending and wind directions change.

    Unfortunately the japanese authorities until now didnt react (since two weeks) but time runs short.
    To do nothing would be omission.
    It is absolutely incomprehensible, why IAEA, Tepco, and japanese authorities do not notice this offer.

    Project outline

    In regard to the acute problem of the remaining necessity to cool the reactors with water and the problem of radioactive particles in the steam, the combination of concrete pump and filtersystem offers the possibility to solve several problems.

    1. Cooling

    2. Exhaust

    3. Filter and separation of radioactive particles

    4. Sealing of the power plant (concrete)

    By combination of a concrete pump , an exhaust arrangement and a fine dust filtersystem most of the radioactive particles can be exhausted on top of the reactor, led to the filter and separated.
    The complete system is built of two parts

    Concrete pump with 58 m outrigger which can pump up to 2600 l/min of water or concrete, so it can hold the exhaust arrangement on top of the building.

    These machines were used in Tschernobyl very often for long periods. By the cable remote control all functions can be adjusted.

    This system holds the exhaust arrangement on top of the building.

    Filtersystem ECOVAC
    Due tot he fact, that radiaton comes from particles ascending from the power plant, these particles can be exhausted by special arrangement. This arrangement can lead particles to the filter, even if they are not directly under the arrangement.

    By tubes which are fixed along the arms of the concrete pump the particles are led to the filtersystem where they are separated by nanofibre cartridges from the air. Separation rates for particles < 0,5 micro-meter are 99,99 %.

    The filtersystem is self cleaning by compressed air cleaning mechanism.

    The exhaust arrangement covers an area of 14-25 m².Air volume ~ 15000 m³''/h

    To our opinion, this ist he only possibility to prevent the ascending particles from dispersing over the country.

    The companies:

    SCHWING has delivered numerous Machines to Tschernobyl in the 80s

    ECOVAC is a special company for industrial environment protection. Their main competence is efficient exhausting of different emission sources and propriate filtersystems since more than 15 years.

    Transport and delivery times

    The concrete pump should go by Antonov or Galaxy.

    We could deliver several units shortly. The first unit within 2-3 weeks.


    Japanese technicians can be trained in Germany or by our persons in Japan. Some translation would be necessary.


    One unit would be around 1.400.000.- €,

    We do not want to have more nuclear power plants, but want to help japanese people in this situation.
    We also believe, that its better to loose face (Tepco) than to loose lifes and pollute the world.
    We know that this is not the absolute solution, but we believe, that there is a better chance for the people to survive.
    If you need more information, please let us know. The mobile number can be reached anytime.

    Yours sincerely

    Dipl. Ing. Bernd Müller

    ECOVAC Filteranlagen GmbH

    Robert-von-Ostertag- Strasse 9

    73525 Schwäbisch Gmünd

    mob: +49 (0)173-9506910

  • Whoopie

    Arnie has a new one up:
    The Implicatio­ns of the Fukushima Accident on the World’s Operating Reactors

    In a NUTSHELL:
    NRC allows vents to be open, whereby less pressure.
    All US plants in danger.
    Zero probabilit­y of containing a leak
    Fukashima should have been able to ride out that storm.
    US reactors..­.Fla has a 50 ft long crack right now
    We could not ride out an EQ like Japan
    Mostly he is TARGETING USA PLANTS.

  • John

    Looks like TEPCO is just patching the nuke stations and basically letting the radiation bleed out. Many months from now enough should have bled out that they can just entoumb it in concrete and say it’s all finished. Lowest cost Chernoble solution. So much radioactive continamination is not spread out that many millions will start feeling the related sicknesses and dying soon. Sorry to say maybe from the beginnning they should have bulldozed it all into the ocean and convered it with cement then. Sad..

  • mothra

    Honestly, this concrete reaction release was disclosed by others before April. I discissed it then. It’s progressed further since. In no way do I assume any containment primary, secondary or otherwise after this period of time. We’d be well served to concentrate on the water table and Pacific contamination. It has to go somewhere until 1,900 tons is accounted for in audit. The nuclear test ban treaty data would be a good place to start atmospherically – make it public! Stat.