Hydrogen levels continue rising at Reactor No. 2 — Now above .50%, highest in months — Explosion risk at 4%

Published: April 30th, 2012 at 7:17 pm ET


Source (Japanese-only): http://www.tepco.co.jp/nu/fukushima-np/f1/images/2012parameter/12043011_table_summary-j.pdf

NHK: 4 percent [is] the level where an explosion could occur.

h/t Anonymous Tip

Published: April 30th, 2012 at 7:17 pm ET


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30 comments to Hydrogen levels continue rising at Reactor No. 2 — Now above .50%, highest in months — Explosion risk at 4%

  • Grampybone Grampybone

    Now there is the data I have been looking for! When that hydrogen count reaches .60% it could start to pose a problem. Not sure how much more hydrogen it will take before the risk of explosion increases. 4% seems like a rather docile number.

    • fireguyjeff fireguyjeff

      Think about how much volume of air gets sucked in to an internal combustion engine vs the volume of atomized fuel (gasoline, ethanol, LPG, etc) for each combustion cycle.

      An old school carburetor offers a small mist "spritz" of fuel for each cycle compared to essentially a full piston displacement of volume for the complete fuel/air mix.

      Hence, this 4% number seems quite within reason to me just from rough estimate, therefore maybe not so "docile".

      I might try to run some numbers this evening on the hydrogen option.

    • snowwy snowwy

      The percentage of risk has been very low all along, even minutes before the reactors blew up. I would personally not rely on any official figures or percentages of risks anymore. After all nuclear power was so safe in the opinion of the nuclear power industries that every singe one of the major disasters never actually happened. Something inside me tells me that 4% risk can swiftly and without TEPCO even considering turn to 99.9 perce… boom.

    • Sharp2197 Sharp2197

      Upon re reading the above, they don't place current chance at 4% but say that when Hydrodrogen reaches 4% explosion is likely. Hydrogen is currently a one half of one percent, If it increases 8 times then explosion is forthcoming. Please correct me if I am wrong.

      • aigeezer aigeezer

        As I understand it, 4% is the lower limit of flammability, rather than the lower explosive limit.


        "The flammability limits based on the volume percent of hydrogen in air at 14.7 psia (1 atm, 101 kPa) are 4.0 and 75.0.

        "Explosive limits of hydrogen in air are 18.3 to 59 percent by volume"

        • The Blue Light.

          The problem with the explosion limits between hydrogen and oxygen is that the mixture can under go a DDT (deflagration to detonation transition). This is were the pressure generated by the deflagration causes the remaining gas to detonate.
          I think the difference between R1 and R3 may well be caused by this effect because the reactor obviously didnt blow up in R3 and apparently neither did the R3 fuel pool.

          • The Blue Light.

            I still think that extra energy was put into the R3 explosion but where it came from has me and my colleges stumped. I don't think anyone has worked out the right answer yet, without full disclosure by TEPCO, of all its infomation, I doubt if we (the public) will ever find out.

            • PhilipUpNorth philipupnorth

              The Blue Light: You have no doubt heard Jim Stone's claim that Fuku3 was a nuclear bomb, set off as a warning to Japan to withdraw it's offer to help Iran get into nukes. This would explain the extra energy you saw when Fuku3 went up. Just asking what you think.

              Admin: My hope would be that you introduce topics one Fuku nuke at a time, say over the next few weeks. I'd ask participants to keep their comments on topic. There has been a lot of noise out there (Jim Stone, et al), but a lot of people on ENEnews have been looking into this deeply since it happened, and I would like to see a review of what we know happened there. It is time to share knowledge once again about what happened at Units 1, 2, 3, and 4.

              For example, Unit 4, so TEPCO says, had concrete walls and roof blown out by a hydrogen explosion with the hydrogen transferred from Unit 3 via a common basement. I, for one, don't think this is physically possible, and would like to know what other readers think really happened there. And, at each of the plants.

              • The Blue Light.

                I like Sherlock Holmes answer to this 'when you've studied all the evidence then the answer is usually the most likely answer'.
                I spent 34 years building and designing Britain's stockpile and during that time I witnessed several test shots. None of the damage that I have seen at Fukushima looks like the damage to concrete structures that I saw in Nevada.
                On the other hand if a small device was used then all the radioactive contamination and constant aftershocks would leave little evidence unless you knew what to look for. When a device is exploded it releases a vast number of neutrons creating radio isotopes in surrounding structures. These isotopes could be detected for decades and could not be created by the reactors or the fuel pools. I think this would be the best way to prove or disprove Jim Stones theory.
                I have been working on a paper to try and explain the two explosions and explain the flaws in some of the other theories (Goddard, Gunderson etc). All being well I should be ready by June/July, unless I keel over. (I am 76)
                Meanwhile I'd like to thank everyone on Enenews for trying to put the world to rights, esp. Dysharmd (for being the first), Xdrfox (for being courageous and insightful) and Anne for kicking me up the arse about learning to use my laptop! I might even learn that new fangled text speak. GOD BLESS YOU ALL.

                • richard richard

                  Thank you Mr 76 Blue Light 🙂

                  Your insight from experience is obviously great to have. We need more turncoats like you, and hopefully more so from the currently employed pool. If we could get all nuke workers to put down their tools then maybe we could bring the industry to a grinding halt.

                  Of course, I know I'm only dreaming 🙁

  • TraderGreg

    I would assume that they can pump more nitrogen to lower the risk of explosion. The other question is where this hydrogen is coming from? Not from 'cold shutdown' I guess…The danger is that at one point of time there will be so much hydrogen that nothing will help and the whole place will blow up again.

  • Sharp2197 Sharp2197

    With number 4 fuel pool in a precarious position, and near daily small shaking from small quakes. I have two question.

    Would the shockwave of a hydrogen explosion at reactor 2 cause a collapse of fuel pool 4 ??

    Do we have any engineers who would hazard a guess ??

  • Whoopie Whoopie

    Going to bed. Pro-Nukes are at it again on above link.
    LOVE YOU ALL…hugs!

  • Ron

    An ad that comes up on ENENews home page:

    "Three top uranium energy stocks to own".

    A Google thing?

    • The Blue Light.

      Yeah, I keep getting EDF adverts, They own more nuclear reactors than anybody else plus they pratically built the French thermonuclear stock pile.

    • snowwy snowwy

      google is logarythmically challegend. what you see is based on what else you search for and what web site you looked at. I keep getting sound mixing software ads and household appliances as this is what i searched the other day

    • Sharp2197 Sharp2197

      I clean my cookies and browser history several times a day. It only takes a few seconds. But then ggogleads uses the title of the article to pick your ads.

  • fireguyjeff fireguyjeff

    Beware of using gmail for the same reason
    The gmail ads will correlate closely to whatever topic words you send in emails via gmail

    • Misitu

      REMEMBER to sign out every time you have finished a gmail, youtube, googledocs, googlemaps, g-images, g-books etc., session.

      Also a REMINDER to get into your google sign up and set the profile to PAUSE webstats.

      h/t UK Daily Mail, some weeks back, around time of g's new T&Cs coming into play.

      For those interested in collection of personal stats by said big search company. Disclaimer: no intention to deprive Enenews of revenue support, purely an information service in this post. Grrr – complicated world.

  • norbu norbu

    I use Ixquick to search no record of IP.