Criticality? Nuclear chain reaction may have caused explosion at France MOX plant, says French nuke expert

Published: September 12th, 2011 at 3:48 pm ET


Gard: “no risk radioactive”,, September 12, 2011:

Google Translation

[…] The accident is probably due to “a few violent chemical reaction,” said Francis Sorin Europe 1 of the French Nuclear Energy Society. “It can also be an explosion due to the criticality, that is to say that at one point, there is a nuclear reaction, a chain reaction that begins but can not last. It is very but low enough to make an explosion, “he said.

“This is the first time it happens to us in 15 years,” said one of Europe ‘s head of occupational medicine. “Do not panic. We keep them informed but for now, we were just asked to lock themselves in the building and not to leave.”

An investigation will be opened in order to determine the exact cause of the accident. The International Atomic Energy Agency, the IAEA has asked France for information about the explosion. The crisis center of the UN agency was “immediately activated.”

h/t Anonymous tip

Published: September 12th, 2011 at 3:48 pm ET


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  2. Explosion at French nuclear plant — At least one dead — Produces MOX fuel September 12, 2011
  3. AFP: “Risk of a radioactive leak” after explosion at French MOX plant — No radiation has made it outside “for the time being” says spokesman — Security perimeter set up September 12, 2011
  4. France says Japan has lost control, French should leave country March 16, 2011
  5. Strange: Nuclear waste being processed during explosion in France had radioactivity of 17 becquerels/kg — 30 times less contaminated than what Japan considers safe to eat September 12, 2011

52 comments to Criticality? Nuclear chain reaction may have caused explosion at France MOX plant, says French nuke expert

  • And I thought I was safe… away from fukushima, here in portugal… France is really close <_< Why are there so many nuclear problems lately? It's too much!

  • lam335 lam335

    But if it were a criticality explosion . . . that would mean fission occurred–and that would mean fission products were created (and presumably released). Wouldn’t it?

    I’m not a scientist, but having heard about criticality explosions for the past six months, that is my understanding of what criticality means and what follows from it.

    If it was a criticality explosion, I bet they will eventually have to admit that radioactive stuff was released, but they will assure us that it was in minuscule, trace amounts–barely about background levels–and there was never any threat to human health (aside from the people who were injured and/or killed by the blast itself).

    • socal stukncali

      Unfortunately you’re probably right

    • Did the dead/injured have contamination levels ?
      The area is a sealed building I would think, they said for them to stay put, ALL dead/injured too ??

      • socal stukncali

        from what i’ve read they have already denied if the dead or the injured have been exposed. if you have google earth try and check it out

      • lam335 lam335

        I believe the French article claims that the injured were not contaminated. I don’t see how that can be IF it was a criticality explosion, but if it was I’m sure they will try to suppress that fact.

        • lam335 lam335

          By the way, it’s annoying the way nuke-industry people talk of “treating” the radioactive waste, when what they really mean is burning it. “Treatment” makes one think of the stuff people spray on carpets to help them resist stains–it doesn’t call to mind images of radioactive smoke and ash going up a chimney and (at least some of it) out into the atmosphere.

          • Hemisfear311 Hemisfear311

            You are right. We could make a list of words and expressions used to make the subject seem less dangerous. They try to lull us into thinking it’s all ok, or rather not to think at all.

    • Arizonan Arizonan

      You got it. Fission products are always created if nuclear materials ‘go critical,’ ie have enough of the right stuff in the right configuration at the right temp

  • dpl dpl

    don’t panic just a nuclear detonation explosion ?
    a wee one , somebody set the timer wrong on the oven is all.

  • The person killed was a foundry worker who was near the furnace when it exploded. The prognosis for the seriously injured worker, evacuated to a hospital in nearby Montpellier, was not immediately known.
    Acton said the biggest concern in the coming hours will be to monitor whether any radiation is released. That will depend in large part on where exactly the furnace is on the site and how well contained it is.

  • The French nuclear Marcoule site, scene of an explosion Monday, is in the Gard region of France, in Languedoc-Roussillon, near the Mediterranean Sea. (Reuters)

  • Flapdoodle Flapdoodle

    New Japanese PM resigns over Fuku gaffe after just 8 days in office. Kinda like jury duty in the US.

  • Hemisfear311 Hemisfear311

    4 tons of used radioactive metal containing at least 67,000 becquerels in exploding foundry.

    After explosion they shut down the webcam close to the plant. Sounds familiar, doesn’t it?

  • lam335 lam335

    So it seems like there are two different accounts. The article linked here says they were melting down radioactive metal in a foundry. I believe one of the earlier reports said they were incinerating “low-level” contaminated waste in a furnace (presumably, contaminated gloves/clothing, etc.).

    • lam335 lam335

      YEs–The BBC story said “The EDF spokesman said blast happened in a furnace used to burn waste, including fuels, tools and clothing which had been used in nuclear energy production but had only very low levels of radiation.”

      • lam335 lam335

        . . . but “very low levels” couldn’t achieve criticality, right?

        • Only requires 2 elements, Right ?

          • lam335 lam335

            I thought criticality required there to be a certain “critical mass” of radioactive material present in one place–though I have no idea how much that actually requires.

            . . . But I only repeat what I found on Wikipedia, so it is entirely possible that I am totally wrong.

          • critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (e.g. the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature and its surroundings.

          • All of which could be variable in a furnace or foundry. Bombs contain controlled variation by slapping two masses of fissile material together, by either the gun method or implosion method, IIRC.

          • Arizonan Arizonan

            Criticality only requires one element that has enough neutron decay to create more decay; ie, it needs enough u235 or pu239 in one place to create a self-sustaining nuclear reaction.

  • farawayfan farawayfan

    Waste capable of a sustained fission to the point of criticality is not “low” in radioactivity. The lies and minimization continue in as unabated a fashion as the criticalities they don’t want to admit to….

  • Do we have a record of the camera up until they pulled the plug?

  • jtb

    abc tv news in the usa just reported on this France action tonight… and actually stated that “fukushima is still spewing radiation” during a quick segment on rising nuclear drama- I was pleasantly shocked.
    Diane Sawyer, she’s the cat’s pajamas!

  • Elenin Velikovsky Elenin Velikovsky

    She’s quite the Cougar.
    “One Hell of a Woman” as Mac Davis sang.
    Unfortunately her position requires her to perform
    the distasteful duty of Fawning and glorifying
    freekin’ RUMSFELD. Did you see that terrible show?
    Old Devil Donny, breaking down and crying over his
    own family problems, and Diane comforting this Demon,
    there, there, it’s all right…

  • Jebus Jebus

    Not to change the subject of “Cougars”, Woof! Woof!
    But here is a good article on the Marcoule site.
    Ya just gotta wonder what they were melting down and where it came from. Is the Fuku Devil spreading by human hands?

    From the last paragraph of this article…

    French officials: ‘Don’t worry about fatal nuclear explosion’
    By Rik Myslewski in San Francisco
    12th September 2011 17:48 GMT


    The sprawling Marcoule facility is used for “the cleanup and disassembly of nuclear installations which have reached the end of their life cycle,” according to AREVA, the contractor managing the waste disposal along with providing other nuclear-industry services such as the production of tritium and the maintenance of nuclear-material transport containers.

    Hasn’t Fuku reached the end of it’s life cycle?
    For that matter, Hasn’t Japan…

  • bleep_hits_blades

    Burning nuclear waste-a standard practice?

    We have been angry & concerned that Japan is burning nuclear-contaminated material… but that is what that furnace in the French nuclear facility is for, isn’t it?

    So, is burning nuclear contaminated material a standard practice?

    • arclight arclight

      i think that they can use the furnace to complete chemical reactions to make isotpes and compounds of isotopes for medical,scientific and weapons development…same as the japanese maybe??

      i suspect that they destroy low level stuff in the furnace too?

    • lam335 lam335

      Apparently, burning what they call “low-level” nuclear waste IS legal. To the best of my limited knowledge, it’s not stuff like spent fuel rods. It’s things like gloves and clothing used by nuke workers that have become contaminated. I know I posted this before, but there was an article this summer that a bunch of this supposedly low-level waste was sent from Germany to the US in order to be incinerated–oh, we’re supposed to say “treated”–at a facility in Tennessee this summer.

      This is probably only legal because most people don’t even know it happens. I think it ought to be made illegal.

  • StillJill StillJill

    I’m thinking for sure Rumsfeld is a lizard.
    I’ve not been ABLE to look at him since about 2006. Alien, I mean. (Go ahead and laugh,….just wait ’til you see his lizard tonque!)

  • milk and cheese milk and cheese

    Notice how they say this is the first time this has happened in 15 years. Which means there were other ‘incidents’.
    By the way, Rumsfeld will be tried in a civil court. It is disgusting that this won’t be an international tribunal, and that he isn’t joined by Cheney and Bush…but it’s something.

  • Stlouieishot

    if the explosion happened in a foundry area, it almost certainly involved plutonium. plutonium will catch fire and burn uncontrollably when heated to i think around 450deg farenheight. the only way to keep this from happening when melting the metal down is to do so in an atmosphere of freon.

    what i think may have happened is plutonium dust had accumulated to a degree where once a mass of it was brought into the furnace it reacted with other amounts of plutonium in the area creating a criticality. this blast of heat and energy may have sparked off a larger explosion.

    one thing i have learned since the fuku accident began is if the governemnt or a company in the nuke industry says “there was no radiation released” it means there was definately radiation released. if they say ” a small amount of radiation was released” it means a large amount of radiation was released. if they say “theres nothing to worry about there is no health concerns” it means that there is a reason to worry and there will be major health concerns.
    if they say one thing, then exactly the opposite of what they have said is probably closer to the actual truth.