Analysis of how far corium penetrated underneath Fukushima reactor (IMAGES)

Published: January 3rd, 2013 at 1:41 pm ET


Title: Severe Accident Analyses of Fukushima-Daiich Units 1 to 3
Source: Japan Nuclear Energy Safety Organization (JNES)
Authors: Harutaka Hoshi and Masashi Hirano
56th IAEA General Conference, Sep 17, 2012
h/t SimplyInfo

“It is assumed that the whole molten fuel fell into containment in Unit 1.”

Full analysis here

Published: January 3rd, 2013 at 1:41 pm ET


Related Posts

  1. TV: Experts conclude no nuclear fuel left inside Fukushima reactor — Total meltdown “highly likely” — Conducting more tests to determine how far down corium has penetrated (PHOTOS & VIDEO) September 26, 2015
  2. Video: Fukushima had “meltdown, melt-through, & melt-out within days of quake” — US Gov’t: Analysis says containment vessel fails after fuel melts through barrier — Experts: Corium may have melted out to reactor building, prepare for radiation doses over 200,000,000 microsieverts/hour March 10, 2015
  3. AP: Melted fuel may have “dropped even beyond” the bottom of Fukushima plant — ‘China Syndrome’ predicted by US gov’t analysis — IAEA Expert: Pools of corium beneath reactors are up to 2 stories high (VIDEO) March 30, 2015
  4. Analysis: Melted fuel completely penetrated concrete in under 15 hours at GE Mark I — Shows little decline in speed (CHART) March 17, 2012
  5. Doctor: Source of Fukushima leakage still not controlled — Reactor cores may be underneath containment (VIDEO) January 18, 2013

52 comments to Analysis of how far corium penetrated underneath Fukushima reactor (IMAGES)

  • Cataclysmic Cataclysmic

    Excellent find..

    • omniversling

      JNES=vested interest=unimpartial. Unreformed (pro-nuke) and re-badged 'regulatory body' …re-badged to get rid of previous odor of corruption and incompetence. TEPCO=proven liars and fraudsters.

      Repost of calculations I made over a year ago:

      GE Mk1 reactors the control (hahahaha) rods come up from underneath, as they melted down with the fuel rods there would have been molten corium flowing down through the holes that the control rods pass though into the control rod drive cavity, quite probably enlarging the holes as it flowed. See:
      At 2400-2800c corium burns through concrete at the rate of 5cm per hour, and the base of the concrete dry well beneath the pressure vessel is about 8m as far as I can discover (anyone with better knowledge?). The time it would have taken the corium to burn through that thickness is about 160 hours. There are 24 hours in a day so 160 hours is 6.6666 days. There's one for the numerologists amongst us! Debbil's work for sure..

      So let's say that after the fuel to start melting following the main cooling system failure during the earthquake (not tsunami, earthquake that fractured the cooling pipes), within about a week the corium would have been into the ground. Providing of course the thermal power of the corium was not exhausted by the concrete as is passed through.

      • omniversling


        Also, Arnie Gundersen puts the temperature of corium closer to 3500C, so could go through even faster, and who knows how fast or far it may have gone through the rubble that FukuSteamer was built on…plus, how many fractures or cracks in the foundations now from hundreds of tremors since…does the rise of the tide now contact the coriums and create all the steam that is rising from the ground and between the reactors now?

        PS, happy new year ENEnewsers…please keep up the critical (oops!), ahh, very very important work of raising awareness, and sharing info here…just as important now (perhaps even more so), as more and more people will 'hear the penny drop' as the USS Ronald Regan sailors make the MSM.

        • patb2009

          at 3500C, the corium eats through the CV in 24 hours.

          we saw that with the buildings losing stability and local ground movements
          in the area.

  • PhilipUpNorth PhilipUpNorth

    Molten fuel was NOT contained by the Containment Vessel. Molten fuel IS contained by MUDROCK under Units1,2,&3. It is ludricous to contend that 60+ tons of 3,000+ degree F of Corium1,2,&3 came to rest within a cavity the size of a cylinder 2.75m in diameter by 1.85m thick. The corium actually penetrated tens of meters into the bedrock underneath Units1,2,&3, cutting quickly through concrete, steel, and mudrock like a hot knife through butter. There remains, perhaps, a coating of corium inside Containments1,2,&3. But only a coating. The area of the containment in the drawing above is but the start of a hole many meters deep into the mudrock. The question remains: How deep? If they want to find out, they must dig slant wells into the mudrock below Units1,2,&3. Until this is done, the extent of the Fuku Disaster will remain covered up. Try again, TEPCO.

    • Cataclysmic Cataclysmic

      Yes indeed Phillipupnorth.. this was the report of what they knew in June of 2011.. and enhanced with backwards radiation detection data..

      Also, notice, how they try to cover up that their knowledge was unrealistic.. now the slow admission to the real facts is starting.. for example,

      "In this calculation, leakage due to overtemperature
      was not considered. Therefore,
      the primary pressure boundary remained
      intact although it’s temperature exceeded
      720K. This was unrealistic."

      and, doesn't it seem like a few slides might be missing?

  • norbu norbu

    P.U.N., Thank you for your information. I wish the world would listen.

    • PhilipUpNorth PhilipUpNorth

      This is a Power Point presentation from an IAEA conference. (Now we're talking, Admin. Great work!). The authors are Japanese. Japanese nuclear scientists simply cannot imagine what has happened at Fukushima. They simply cannot believe that their nuclear machines, so gigantic and so robust and well-designed, have so utterly failed them.

      The problem is that every day 10 million bq of radiation "leak" from the ruins of the plant. Ground water flows over and around Corium1,2,&3 where it lies in the bedrock under Units1,2,&3. And right out into the Pacific Ocean. I am doing my part by not eating Pacific Ocean seafood. I am not alone. An entire industry worth scores of billions of dollars a year is being destroyed by these pinheads, who believe their puny steel and concrete "Containment Vessels" halted the flow of 3,000+ degree F molten nuclear fuel.

      These pinhead nuclear scientists should be designing a massive thermal heat sink to cool the three Rogue Nuclear Reactors located in the mudrock under Fuku. Instead, they are debating whether the corium is contained within the "Conservative" measurements suggested by TEPCO, or the "Less Conservative" measurements used by JNES nuclear engineers. Both are terribly wrong. Until these pinheads get over their assumptions that the corium was "contained" within the buildings, Fuku will remain a mess without a solution. And the Pacific Ocean Fishery will continue towards its utter destruction.

      • nedlifromvermont

        thank you phillipupnorth for your valuable insight on this!!!

        maybe GE ought to get on the ball … but then they would be admitting guilt and opening company to liability lawsuits, no??

        and as far as Japanese malfeasance in government and at TEPCO is concerned … isn't this pro-nuclear propaganda farce exactly what GE hath wrought, with US government and military complicity, in post-war Japan, in our (USA) name and on all of humanity's behalf, supposedly …

        a GIGANTIC MARKET AND REGULATORY FAILURE of the highest order …

        requiring billions in hush money to castrate the Mainstream Media …

        to make it look all fine in radioactive and dying Japan …

        … just another garden variety industrial accident …

        … happens all the time … coal mine fires and volcanoes …

        … Hindenburg fires and Titanic disasters …

        … move along people … there is nothing here to see …

        … we are decontaminating now and soon will all be singing Kumbiyah and eating rice grown in Minamisoma …

        … this nuclear fiction of control and containment is disgusting and debilitating ….

        … but maybe … just maybe … the truth of the matter is far worse, …

        … and the Sheeple just really would rather not know they are being slaughtered …

        … why bother the animal on his way to the killing floor, with news of where he is headed …

        … these are heavy thoughts …

        peace … oh, and yeah, I agree, PUN, PINHEADS!!!!


        • Dr. Anne Lee Tomlinson Maziar anne

          It's GE Hitachi now:

          GE Hitachi Nuclear Energy

          • razzz razzz

            GE Hitachi or Hitachi GE is referred to as an alliance but is a partnership, with GE being the parent company. GE Hitachi is a subsidiary of GE. Start at GE's site and figure it out from there. (Headquarters's address is a good tip off)

            GE won't sell its nuclear division until it is about to start losing money for them, it just gets stupid heads like Hitachi to bear some of the costs of screw ups and failures.

            Basically, have someone else around to blame.

            • nedlifromvermont

              GE … GE-Hitachi … Westinghouse …. it don't matter … I blame GE for the nuclear HOAX … because I'm directly related to the first president of the company … that built the machines … that destroyed Japan … so for me it's personal … and I can't get off it … I don't think Charles Coffin would have sanctioned (been bamboozled) by the nuclearists … but it's academic … he died in 1927 … I always wondered why my father went to Japan in 1969 … he knew the nuclear decision spelled doom for this beautiful land … so sorry … so sad … so stupid …


        • Anthony Anthony

          Awesome and insightful. This stood out to me –
          **… Hindenburg fires and Titanic disasters …**

          A smart metaphor against Fukushima adds to the glare of lies. First I was thinking the tie in lesson was how nobody attempted to *ride* a deathtrap or tempt fate twice now that you know better, but really, the real insight tying Fukushima, Titanic and Hindenburg is simply that they are all deathtraps.

      • Anthony Anthony

        You are right. And you cant simply *lose* three multi tonnage nuclear molten coriums into the ground and not expect a natural set of processes not to take place. I think the added outputs of the coriums jacks the 10 million Bqs right out of the orbit to a higher reality number.

  • AGreenRoad AGreenRoad


  • AGreenRoad AGreenRoad

    Total Fukushima Radiation Released Into Ocean, Air, Groundwater, Storage Tanks; via A Green Road

    Fukushima Spewing Equivalent of 112 Hiroshima Nuclear Bombs Worth of Radiation Every Hour; via A Green Road

  • AGreenRoad AGreenRoad


    What is more difficult is believing this propoganda that NOTHING happened.

    No immediate harm to health

    Keep smiling, or it is all your fault

  • Sickputer

    Tepco eggheads with their simpleton graphics can't and don't want to explain a damn thing.

    They might have well release a one page handout that says:

    Things went boom! Crap burned down! Radiation is everywhere! Our ass is grass!

    SP: So they need more R&D to find out what happened. We can expect their few remaining mutantized descendants in about 500 years will finally dig down and see the path of what killed central Japan.

    They don't mention the pathway through the bottom control rod holes which I think is odd. They do mention GE's vaunted startup instrumentation sensors as an egress pathway. Those tubes are supposed to last 8 years. I think they were burned through in about eight minutes:

    Page 11: "Results are reasonably consistent with each other"

    Oh really…None of those entities are even close in their estimates of radiation releases.

    About CRIEPI…they are a Japanese bastard child research center for the nucleocrats with this entry on their history page:

    For 2005: Revision of seismic design criterion for nuclear power plants.

    Kyushu Electric Power Co. obtains consent from local residents to utilize plutonium in LWR.

    SP: I bet the Kyushu folks are thrilled now.

    Tepco…go away and don't explain anything…you guys make the Keystone cops look intelligent.

    • Anthony Anthony

      God Sickputer, and then YOU break it down for us! You bring an energy of someone in their twenties with a wisdom of the Ages at your fingertips. One of a kind. I always appreciate your perspectives for sure.

  • jec jec

    If the Corium is contained..they have a GREEN light to tunnel under and contain it! GREAT NEWS!(sarcasm) Hey TEPCO, isnt the plan to build steel "dams" around the site? And how is that going? Little bit difficult? Is there radiation the deeper you go? Just saying..

    • Anthony Anthony

      I imagine one could scan somehow and get a thermal or other imaging technique to see them? These corium diagrams are much too pretty for me to believe they accurately reflect the ugliness this accident really is. Like if two years later they are just sitting there nicely like they portray you would see massive steam evidence and boiling water etc? 3000 degrees!!!

      • Sickputer

        Anthony posed this query: "I imagine one could scan somehow and get a thermal or other imaging technique to see them?"

        SP: It certainly seems that they should be able to detect a fireball in the ground. With all their technology why can't they do it?

        Answer: Two possibilities at a minimum:

        1. Maybe they have that information and don't share. The news of what the coriums are really doing may be so horrific that they dare not publish their findings.

        2. Or…(and I am leaning slightly to this answer) they actually don't have any human means of penetrating the subsoil areas to get an accurate view of the coriums.

        There are super radioactive hotspots blowing up steam from the subsoil under 1-3 and they really can't get into a position to measure it from above. Robots have expired by the handfuls in Units 1-3. Probably many more than they have posted death notices.

        So unless they feel like drilling some slant wells as Philip and others have suggested…they are just praying the fireballs finally cool down a few thousand yards down into the sedimentary layers.

        Nuclear scientists remind me of oncologists and other internal doctors. They are very educated, have great tools, and yet they don't know the answers to so many riddles about human anatomy and the behavior of runaway nuclear cores.

        Now what happens if the corium bores down so far it hits the methane layer? The world wonders…

  • moonshellblue moonshellblue

    I thought they were using Muons to detect the location of the corium. Assumptions are inane when discussing the location of molten nuclear fuel. What about all the criticality's we have observed. Did they take this into consideration with their assumption. As with so many issues TEPCO has once again left me with more questions than answers.

    • ForwardAssist ForwardAssist

      That detection technique with the Muons requires that the corium be located between two detector arrays, one on either side. Which in the case of Fukushima would mean that at least one of the arrays would have to be below ground, because that's where the cores went. That whole concept was a pipe dream, they were praying that the cores were still above grade. I suspect that they knew the answer but refused to accept it.

  • razzz razzz

    They do admit (hard not to from past pictures) that Unit 3'a equipment hatch blew open but don't say how it blew open. Being on the 1st floor and ajar it loaded the entire building with hydrogen (and probably steam), so that doesn't make much sense because, how and when did the door blow open or how was the entire building loading up with hydrogen before it finally exploded if the door wasn't ajar yet?

    Anyway, hydrogen ignited and shocked Unit 3 fuel pool because the entire building was loaded with hydrogen before it lit off. Of course Unit 1 they say was a horizontal explosion and don't account for why Unit 3 was a vertical explosion.

    Unit 1 was your typical containment lid leaking hydrogen like a little teapot until it lit off in the upper floors.

    Unit 1 shows the pedestal that supports the reactor was breached, but not how it was breached. Shows a round(?) wall, inner and outer, with a skirt embedded (probably steel) with corium flowing through it to the outer containment floor itself (another failed hatch?).

    Unit 1 drawing shows the corium had another foot of concrete to burn through just to get to the embedded containment shell bottom.
    Even if they were right all (3) units still leak like sieves, which is about the same as being underneath the buildings.

    An outside independent agency rendition of events would be interesting. Think GE knows why and how their designed failed?

  • PattieB PattieB

    Umm… GUYS!? Am I the only one who remembers the vid of when they DID such a core series? The guy with the can that had the "YELLOW coated Concreate"? that was pushing over 500 rads? They did that… Uhm, June? I think it was, back in 2011… it was a slag sample from the groun UNDER the #1 reactor… and that says conclusively that the core did an excursion from the building. That was the SMALLEST of all the reactor cores! Their own scientist did a study on where the core sits now.

    • PhilipUpNorth PhilipUpNorth

      Patti, can you please provide a link on this drilling? I must have missed the results. Can you add the link here as a reply today sometime? (I will look as well.). Many thanks!

  • Aaaaagh, pastel colours, bold well spaced lines, cut-away profiles, so clean. Who googled for eggshell colours for that presentation – so sublime for an extinction event..

    • Time Is Short Time Is Short

      The best comment of the day!

      h/t 53north

      Don't be a stranger.

    • Sickputer

      Very good 53n! ("so sublime for an extinction event..) +311

      SP: I watched last night a two-hour history of the world (focused on humans and their migrations to all parts of the globe) and your extinction remark reminded me of an interesting comment on that show.

      They made the remark that the many thousands of years in which humans migrated to occupy all the continents provides some "extinction insurance" for the human race.

      I think we all think about that from time to time as we mention Southern hemisphere places that seem likely to have the best shots at keeping the gene pool going for another 800,000 years.

      So a big evolutionary salute to all our Enenewsers who live below the equator!

      We're counting on you guys if our butts get toasted up here in the insane Dr. Strangelove world of nuclear madness.

  • ftlt

    Wiki Fukushima

    A pro nuke mob scrub job for 3 years now…

  • PattieB PattieB

    This girl lives danger! She went hunting for a fuel fragment from Chernoble… and found one!

    • behappy1

      that was crazy
      yet so cool, thanks

      that tiny, and she found it
      yet the experts at the plant can't find 100's of tons

    • Au Au

      OMG! On so many levels! And we used to think playing with mercury with bare hands was unhealthy.

    • razzz razzz

      If I understand this correctly, that fragment was from a working reactor and spent fuel is even more radioactive *thinking when Unit 3's pool blew or probably vaporized most of its fuel* what they fear might happen in 4's pool already happened in 3's pool.

  • behappy1

    so after the explosions there are most likely thousands of
    these everywhere.
    so when someone takes a reading, unknown to them 1 ft away
    the reading could go off scale

  • PattieB PattieB

    yes, that's about the sum of it! Japan now also has similar problem, raised exponential leve, as the had a moderated criticality… and got particulated plutonium carried on the winds that "Dusted" as far away as Tokyo! The Tepco west coast plant spewed stuff as well, though they kept a much better lid on it. Effectively… half of Japan is now a toxic waste dump, and then now the burning of such waste, is slowly raising the percentage of contaminate land mass.

  • PattieB PattieB

    If you ever wondered WHERE these meglomaniacs come from?… watch this vid! The kid SCARES ME!

  • PurpleRain PurpleRain

    I have a question that I'm not sure where-else to post. Can a radioactive hot-particle be photographed (by accident even) if it is traveling thru a night sky? A photographer on another site caught a strange aberration when they were trying to photograph a barn on a cold winter night up north (i think it might have been Wisconsin)…and well, I hope I don't get into trouble, but just want to ask if it might be possible?


      couples of challenges PurpleRain, in capturing images of radioactive particles: the technology used to capture the image will determine the quality of same. Digital imaging versus film emulsion produce different results. Free-floating particles cannot be captured by either technology, as the must strike the detector/emulsion to register their presence. Whatever you thought may have been captured when photographing the barn was not a hot-particle. If it were a plasma ball (which are known to exist), I cannot speculate to its originating source…

      • PurpleRain PurpleRain

        Aftershock, Thank you for responding..and thank you also to others for granting me this question under this topic. The digital photograph is not my own. A photographer captured a strange image on another website and while others were making suggestions about orbs and rods and technical lens-type equipment probabilities etc. I was the one who wondered aloud and mentioned it to others there and hence, wanted to ask the question here. This link might work, not sure if anyone wants to see.

  • Heart of the Rose Heart of the Rose

    Here is the Geology of Fukushima

    I think the coriums are leaking ..into the ocean..below the waters surface..and I also think it is disturbing the shoreline geology in many ways.

    • PhilipUpNorth PhilipUpNorth

      "This also means that the radionuclides will naturally be carried towards the sea by this underground water stream flowing through the permeable layers of sandstone." From the report linked by Heart. Anne agrees with you on this point, Heart, that the corium has also followed the sandstone layers, and is now under the Ocean. So the corium is under the Pacific Ocean, out of human control forever, with no possible remedy? Just great!

      Fuku Recap:
      Two reactors exploded.
      Three spent fuel pools burned.
      Four spent fuel pools are open to the atmosphere.
      Spent fuel assemblies are too corroded to be handled, and are likely to spill fuel pellets into the spent fuel pools as they are handled, causing additional criticalities and radiation releases.
      Three coriums are likely to have followed sandstone layers, flowing down and now sitting somewhere under the Pacific Ocean, where they will contaminate Earth's largest ocean for hundreds of thousands of years.
      Can somebody please remind me again why we ever got into nuclear power in the first place?
      Safe? Cheap? No environmental pollution? Clean? Oh, sure. Now I remember all those pretty pictures from when I was a child, as GE brings "good things to life."

      • Heart of the Rose Heart of the Rose

        The whole location is on the Futaba shear zone.
        A shear zone..on a volcanic and earthquake island.

  • Heart of the Rose Heart of the Rose

    Here is the Geology of Fukushima

    I think the coriums are leaking ..into the ocean..below the water's surface..and I also think it is disturbing the shoreline geology in many ways.

  • Heart of the Rose Heart of the Rose

    PS..Including activation of the fault..

  • Heart of the Rose Heart of the Rose

    What fault?…scroll down…and download.

  • markww markww

    This is all a guessing game till TEPCO AND JAPAN lay it out on the Table.

    Grasping at straws and no real answers,and where is the UPROAR from the Population of the planet