Ex-Fukushima Daiichi engineer as ‘cold shutdown’ declared: Fuel rods still active and alive — Most worried about recriticality — Tepco must measure neutrons near core (VIDEO)

Published: April 12th, 2012 at 12:27 am ET


A confession of an ex-Tepco worker
Translated by: Goldieluvmj
Original Upload: LunaticEclipseKimura
First broadcast: Nov 25 2011
Published: Apr 11, 2012
Via TBS Blog: Confession of TEPCO employees, 2011/11/29 17:56
h/t arclight

Subtitles have been embedded on this clip for those having trouble viewing via CC button in YouTube toolbar — Watch the full broadcast at bottom of post:

Part 2 At 9:00 in

REPORTER: As an ex-TEPCO employee who handled the nuclear fuel rods and have worked at the Fukushima Daiichi nuclear power plant, [Toshio] Kimura is most worried about the recriticality.

KIMURA: The fuel rods are still active and alive. Rather than putting more effort in cooling the fuel rods right now, a contingency plan, in case of a recriticality, must be considered. They should have prepared the plan before they started to work on cooling the fuel rods. I think it’s a matter of urgency.

REPORTER: Kimura thinks that there is still a risk of melted fuel rods to become active. Living far away from Fukushima, he still worries about the fuel rods in the reactors to this day

HOST #1: Here is the reporter Matsuda. Mr Matsuda, Mr Kimura is the actual person who operated the reactor, isn’t he? He gave me a startle when he said that the inside of the reactors are still alive.

REPORTER: It seems that they don’t know exactly what is happening inside the reactors.

Most of his concerns were, an importance of maintaining the non-recriticality state and observation of any recriticality signs.

Tepco explains that they are watching the signs of recriticalilty by observing the change of temperature and pressure levels.

In fact, Mr Kimura called the main office of TEPCO in October and he told them that they should measure, interference evaluation as a guideline, the neutron emission rate near the reactor core.

The govt is aiming to bring the reactor temperature down within this year (2011).

But Mr Kimura said that unless TEPCO measures the neutron emission rate, reassurance offered by the government is nothing but the word […]

HOST #2: I got goosebumps from the warning he made about the danger of tsunami and nuclear power station. I think he had an extremely accurate foresight and predicted the danger of the accident. I am so shocked.

30-minute broadcast:



Published: April 12th, 2012 at 12:27 am ET


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33 comments to Ex-Fukushima Daiichi engineer as ‘cold shutdown’ declared: Fuel rods still active and alive — Most worried about recriticality — Tepco must measure neutrons near core (VIDEO)

  • Sickputer

    The spent fuel rods are enormously hot even after 10 years fully submerged in a spent fuel pond. Anthony posted this PDF link 6 days before the massive China Syndrome steam of June 10, 2011:


    Read pages 18-19 to get a statistical feel for how bad the situation is with spent fuel rods. Tepco has no realistic chance to begin pulling out fuel in December 2013. They have no hope that anything can be done so they are just waiting for the inevitable just like Enenewsers.

    Also looking back in the archives (understandable we forget so many excellent postings) there was speculation 94% of Unit 3 fissile core melted quickly through the inner vessel by March 14 (day of the blast) aided in part by steel becoming brittle from the cooling seawater corrosion effect. The brittle core vessel bottom just shattered and let the fuel plunge to the lower containment very quickly.

    The plot thickens… Remember the NRC got the Japanese to stop the seawater shortly after the discovery of the massive new airborne radioactive molecules that were at huge levels in the air over the West coast.

    Also some speculation the remnants of Unit 3's spent fuel pond left after the massive expulsion dripped on down and merged with the fissile fuel into a larger melt-through corium. The much higher thermal activity of MOX fuel rods makes this super corium very dangerous despite being smaller than the coriums at Units 1 and 2.

  • dharmasyd dharmasyd

    Toshio Kimura. I send my deepest thanks to you. I will forward this to a friend who is building, in much the same way, an off-the-grid, sustainable community in upstate NY. It will inspire her, I'm sure. This story brings hope. We must keep trying to make it through.

  • Misitu

    I've been doing a frame inspection of the recent endoscope visualisation of reactor 2. I need to isolate some segments of extreme interest and add some commentary. In the interest of keeping it current there won't be time to set up a linked webpage and otherwise I'll need to refer an interested readers to time segments and frame numbers.

    Nothing of deep scientific knowledge, just visual observation. But might be useful nontheless. I guess that Tepco releases these in the hope that somebody in the world can interpret for them.


    • Misitu

      Brief update.

      After half the video which is out of focus it seems we start looking at the bottom of the RPV due to the presence of bubbles coming up from the active core melt. There are some quite violent explosions and rubble/powder expelled and settling. Later it seems we move back up to a level without liquid water: there are plume like swirls of vapour, and there are also what look like condensation drops on the illumination fibre. Even high up there are expulsion events happening. The activity of the hot yellow stuff is impressive, it does not keep still for a moment and even at 30fps it's difficult to see where something starts or finishes. Interestingly, some surface structures from before an event are recognisable after disturbances which hide them, at the same time these structures exhibit strong mobility. The explosive events sometimes display as white zones (white hot?) and at peak what looks like gamma noise on a black background blots everything else out.

      Having had a look it's my aim to cut a few clips out and pop them on yt or google dox. Sorry, I am a bit slow.

      Basic conclusion, there is a lot of very active core melt in this RPV and not a lot of it is under water.

      Rendering note, the visibility of the fibre light pipe and the very hot events taking place do suggest that the camera is on quite long tele/zoom, without that it has to fry.

      • Misitu

        … "Good News there's a lot of core still in 2RPV, Bad News not much of it is in contact with water" – this fleshes out, in a depressing kind of way, Tepco's comment that "there's a lot less water in there than we thought": thought, erm, hoped.


  • razzz razzz

    When the Great Quake first happen along with the ensuing disaster(s) at Fukushima, I had no clue about the inner workings of a nuke plant. Then found out radioactive steam and water circulates in loop to pass directly through the core while driving the turbine generators in these Mark I, II, III, etc., BWR designs besides designing from the onset a core encasement that looks like a sieve on the bottom with a containment system that expects heat to go down and not up, I then understood why a couple of the original members of the Mark I design team, quit and went anti-nuke in protest of this design.

    If making a nuke plant for power generation, I would have thought at least they would use a PWR design like used in submarines.

    So my first reaction after the (3) units at Fukushima were hopelessly in meltdown mode (about time they were attempting to dump seawater on the units), why not drop a nuke bomb on the entire plant site? Pick a nice calm day with perfect conditions to get the fallout to rise straight up and high into earth's atmosphere to fall back to earth's surface measured in centuries just like the rest of controlled nuke bomb testings of the past.

    Well, now I read that just to this point in time, the Fukushima disaster has already released the equivalent fallout of the entire nuclear bombs tested in one year, 1963(?)…[continued]

  • pure water

    Practical operators sometimes develop intuition about their machines, just because they work with all their senses and attention and follow the changes both on mental and sensory level.

  • labmonkeywithagun labmonkeywithagun

    6.9 and a 6.2 on top of each other in the Gulf of California.

    • Toadmac

      Its getting to be common place and therefore not worth mentioning on the MSM,s. Nothing to see here,no damage,no injuries,no tsunami,nothing new,no story so go back to sleep. I think the nuclear ELE stakes are getting higher and higher every day they stay running!!!

  • razzz razzz

    [contining]…There is still the SPF ponds of 1, 2, 4, 5 and 6 holding rods and the cores of units 5 and 6 still loaded besides the common pool storage pond with the most mind-boggling amount of rods in one place.

    Anyway, when I posted my idea of nuking the site via dropping a bomb, it was quickly pointed out to me the amount of fuel involved (a tolerant response at another website) and the total amount of fallout that would be generated in such a scenario including from plutonium fuels and byproduct.

    So, now I am just resigned to a fact of a slow and continuous bleed-out of fallout from Fukushima, into the atmosphere, lithosphere and hydrosphere. Without another great quake, maybe in a hundred years they can clean the mess up but not before the invisible poisons affect generations to come.

    Still I wonder in desperation if the nuclear site's fallout wouldn't be better off floating high in the sky. Just a higher background radiation standard that keeps growing larger everyday anyway to be shared by all.

    • Sickputer

      I've considered many times the possibilty of a modern day Operation Plowshare using horizontally drilled and shaped low fallout small kiloton neutron bombs. I know the Big Two (Russia and US) surely have a few remaining from the Cold War.

      Technically the window to bomb with best success is before the runaway coriums get too deep. That window is possibly still open. The reluctance to do this obviously risky procedure is understandable. The procedure could make the contamination worse. The bombers would be heroes if they succeeded, brcause if it fails then the outcry from the world would be enormous.

      Yet the biggest unspoken deterrent is that such a desperate gamble would make it loud and clear that nuclear power plant technology is unsafe everywhere in the world. The entire industry would be doomed to extinction.

      So in the face of those possible repercussions a bomb is off the table…for now. But the climate for desperate measures can change overnight with such a mindless alien enemy spawned from the loins of Dr. Frankenstein nuclear engineers.

      If the plant gets totally out of control to the point workers flee forever the deadly island and the Tokyo Flight begins…then may be the time for desperate last hope measures.

      • CaptD CaptD

        Right On…

        IMO Far better that "The entire industry would be doomed to extinction"
        … Than Mankind get doomed to extinction…

      • Misitu

        Excellent logic, SP

        I believe that unit 2 still has plenty of melted core inside. The evidence is from the recent (2nd) endoscope survey and comparison with the French Fukushima blog which had a video of live corium-like material burning in a crucible. It appears though that there is both water and air in contact with the stuff, being that bubbles are visible and also condensation. I'm in process of cropping the video and intend to put it up on my google docs but feel free to have a look anyway. The first half approx of the source video is out of focus but the remainder is good and there appear to be some explosions and a lot of mobility down there.

        I believe now, with this evidence- albeit not possible to quantify- that the earlier "announcements" of melt through could have been phrased to extract remediation funds from the government rather than being an accurate rendering of what has been happening. But who can tell? Better instrumentation is absolutely necessary. WWII produced a quicker response to this kind of thing, all kinds of new science were invented then. Matter of survival and so is this.

        My best plan is still for a scorched earth and rubble collection zone. For me, there are measurable risks in this whereas the bomb answer has less measure in the risk outcome.

        Yes, the window could still well be open but a massive ground clearance and measurement task force is I believe the safer- if costlier- option.



    • Heart of the Rose Heart of the Rose

      Fuel rods active and alive..yep…and BURNING.

  • RutherfordsGhost

    We've all send the night-time web cam criticalities – and also the night-time neutron and x ray 'noise' on the CCD cameras there.
    No great surprises … water is an excellent moderator for slowing neutrons for piles of molten uranium and plutonium.

    As I've said all along. Build a big slurry pipe from the reactors – get a serious rock crusher, and process the plant, concrete and surround materials into a slurry – and pump away for chemical processing on a huge scale. You can then suck up the ocean bottom for 30 km around and do the same.

  • razzz razzz

    You keep letting neutrons fly around freely the whole entire site would become unstable. Unworkable. Irradiated. Same as any cooling water or ground water continually contacting the corium(s), equals more and more fallout (nuclear waste) to dispose, store or deal with.

    They can't approach Units 1 and 3, think if the entire site was that 'hot' (contaminated).

  • arclight arclight

    john pilgar???? the reactors didnt flood, the earthquake was smaller… now im off to write a book??

    cough! :/

  • arclight arclight

    oh and thanks goldiluvmj for your hard work doing this translation.. hope you catch up on the zzzzz`s etc!

  • jackassrig

    I think much of the water in the SFP was splashed out during the earthquake. I think the rods were uncovered for quite sometime. With the intensity of the jolt, I think the water splashed out of the pool.

  • Heart of the Rose Heart of the Rose

    There is no suspended animation…with uncontrolled nuclear material.

  • jackassrig

    Sloshing is the term that is used in the literature. The forces due to sloshing of liquids in tanks offshore or due to earthquakes can be extreme. Any rolling action causes the liquid to crawl up the side of the tank. This causes the center of gravity to move due to the change in shape. Instead of a rectangular shape the fluid assumes a triangular shape. This shifts the center of gravity. The problem with the SFP is that it is open at the top. With the massive size of the SFP, the rolling of the liquid from side to side would cause huge stresses in the containment wall particularly at the corners where stresses are high at best. The NRC may be right that the SFP was destroyed after the jolt.

  • Heart of the Rose Heart of the Rose

    Yes …somewhere ..oh gosh..in the NRC docs they discuss..sloshing..of the water…
    No can search for it today…it's in there.

  • steve from virginia

    Fukushima Daiichi isn't hopeless, far from it. It is an engineering challenge, no more.

    There is a great deal of new and useful industrial technology that can bring the radiation releases under control: directional drilling, slurry-wall construction, long wall mining, remote control equipment, etc.

    Problem is, Tepco/Japgov's idea of technology is office chair and daily doses of hopium. Not good enough

    More of the same inaction guarantees failure: fire, explosion, abandonment of the site, abandonment of large area of Japan.

    Japan … chair. No brainer, right?

    • Is that West Virginia ?

      : |

      • Wreedles Wreedles

        … and an Ad Hominem attack is helpful how?
        Steve has a fundamentally accurate point, in that the human race must solve engineering problems that are now considered insolvable, if it is to have any hope of survival. Further, there is a very small time-window, and the clock is tick-tick-ticking. One thing is for certain; the continuing failure by those who are currently 'running' the show is unacceptable, unless our only future is to be to live a few more years in relative comfort until nuclear oblivion engulfs us all.

    • Hutington W.V., I know some people up that way are you near there !

  • CaptD CaptD

    Another quake today near by…

    Wake Up Japan before it is Too Late…

  • glowfus

    dinky little robots that do fine on the moon up against irradiated concrete 24 feet thick. we're not fooled.

  • CaptD CaptD

    Posted today:
    Plans for Fukushima Daiichi Reactor 4 cover revealed on same day TEPCO applied for 1 trillion yen injection of public funds