Japanese Diplomat: It is speculated that melt-throughs at Reactors 1-3 might lead to ‘unintended criticality’ or steam explosion

Published: June 14th, 2012 at 2:54 pm ET


What Is the United States Government Waiting for?
By Akio Matsumura
June 11, 2012


I was also astonished to hear that many Japanese political leaders were not aware of the potential global catastrophe because they were not told anything about it by TEPCO. I find it difficult to understand their mindset. Why would the Japanese political leaders think it appropriate to depend on one source (with an obvious and inherent conflict of interest) to judge what issues have resulted from the Fukushima accident and who is most appropriate to handle it? As a result of this myopia, Japan’s leadership lacks a clear picture of the situation and has little idea where it is steering its country and people.

Let me clarify briefly why Fukushima Dai-ichi remains an enormous danger for which no scientists can recommend a solution at the moment.


  1. In reactors 1, 2 and 3, complete core meltdowns have occurred.  Japanese authorities have admitted the possibility that the fuel may have melted through the bottom of the reactor core vessels. It is speculated that this might lead to unintended criticality (resumption of the chain reaction) or a powerful steam explosion – either event could lead to major new releases of radioactivity into the environment.
  2. Reactors 1 and 3 are sites of particularly intense penetrating radiation, making those areas unapproachable.  As a result, reinforcement repairs have not yet been done since the Fukushima accident.  The ability of these structures to withstand a strong aftershock earthquake is uncertain.
  3. The temporary cooling pipes installed in each of the crippled reactors pass through rubble and debris. They are unprotected and highly vulnerable to damage. This could lead to a failure of some cooling systems, causing overheating of the fuel, further fuel damage with radioactive releases, additional hydrogen gas explosions, possibly even a zirconium fire and fuel melting within the spent fuel pools.
  4. Reactor No. 4 building and its frame are serious damaged. The spent fuel pool in Unit 4, with a total weight of 1,670 tons, is suspended 100 feet (30 meters) above ground, beside a wall which is bulging outward. If this pool collapses or drains, the resulting blast of penetrating radiation will shut down the entire area. At the Fukushima Dai-ichi nuclear power station, the spent fuel pools alone contain an amount of cesium-137 that is 85 times greater than at Chernobyl.


h/t Ayako Oishi

Published: June 14th, 2012 at 2:54 pm ET


Related Posts

  1. NRC’s possible worst case scenario: Examined MOX at No. 3 — Also speculated steam explosion would “reject an entire core” from reactor March 6, 2012
  2. Goddard’s Journal analysis indicates steam explosion at Reactor No. 3 — NRC discussed steam explosion ejecting entire core (VIDEOS) April 10, 2012
  3. More serious than a meltdown — Japan Gov’t now raising possibility that fuel had a “melt through” at all 3 reactors June 7, 2011
  4. Japan media reports on new daytime video showing steam rising from Reactors No. 2 and 3 — Asahi: “Under the steam are the reactors” (VIDEOS) September 27, 2011
  5. Fukushima Plant Chief after 3/11: “Reactor 3, probably steam explosion, it just happened!” — NRC Chairman had said a steam explosion could “reject an entire core” (VIDEO) August 9, 2012

12 comments to Japanese Diplomat: It is speculated that melt-throughs at Reactors 1-3 might lead to ‘unintended criticality’ or steam explosion

  • markww markww

    I already have tried to send out how to stop this problem to media and others but so far I do not even know if it has gotten to anyone important

    • fredlvie

      the only way to stop the core from a melted reactor to spred radioactivity across the world is to drop a h-bomb (of course after immediate evacuation of the vicinity) on the unit.in the midst of the explosion there are millions of centigrades plasma that will destroy any active nuclides.there will be ONE big bang.with (of course) massive radiation TOO.but afterwards there would be NO further contamination due to unextinguishable melted core…

    • fredlvie

      but in case of fukushima it seems that the cores of units 1+3 have been blown out into de vicinty due to exploding rpv's.i think there is no more fission inside…
      but what is the situation in unit 2??????????


  • tjharleycjmp

    So the plan is: sit and wait and hope?

    and nobody cares,

  • for others with bright ideas, some folks you might like to share with

    US government officials


    Jet streams, debris tracking and other rad monitoring links

    Fukushima radioactive fallout forecasts and other rad updates

    Aloha to everyone doing what you can!

  • BreadAndButter BreadAndButter

    Thank you Mr Matsumura, great synopsis of the mess we're in. Let's hope some of the VIPs you work for lend you their ear.

  • TheBigPicture TheBigPicture

    It's all, do what you want with your own reactors, with no checks and balances. And obviously different for each country. And also for each power company, as proven by the current situation. Free form. Wing it.


    It's just one of the many reasons why nuclear technology must be outlawed. Now.

    • Buffalojam

      We see this same unregulated pattern in all of our major institutions. What's more, even when disaster strikes as a direct result of deregulation, industry leaders (like BP in the oil industry, JP Morgan in banking and finance, Tepco and GE with Nukes, as well as their bought and paid for politicians and media reps) scream bloody murder when the need for tighter regulations are even mentioned. It seems that nothing will change until these industries collapse under the weight of their own greed and corruption, even when the lessons available from recent disasters are obvious to all. Of course, the problem is that we will all go down with them when collapse occurs.

  • markww markww

    There is a way to stop the burning of the Massive cores burying underground. I have sent the elements and class D extinguishing materials to the senator that went to Japan. Class D liquid firefighting material can even put out zirconium fires and the other elements i listed here a couple weeks ago can also be used to shield and surround the stuff so hopefully people got it and are working on the now. MARKWW

  • takedake

    Here's the direct link so you don't have to interface with Facebook aka NSAbook: