Err, Why?

A key concern is that another major earthquake could cause cracks in the pool, which is nearly 100 feet above the ground, allow the cooling water to escape and expose the rods to the air. That would allow the zirconium alloy cladding to ignite and release radioactive material into the air.


Zircalloy
does not spontaneously combust on exposure to air. Heck, I’d be long dead if it did, having handled a few hundred tonnes in my time. Yes, even the sort of tubes that they’re talking about here.

I’d be really, really, grateful is someone could tell m where this story is coming from. Here’s the actualy skinny on Zr and zircalloy:

Massive zirconium metal scrap can be handled, shipped, and stored with no evidence of combustion or pyrophoricity hazards. Mechanically produced fine scrap such as shavings, turnings, or powders can burn but are not pyrophoric unless the particle diameter is less than 54 ..mu..m. Powders with particle diameters less than 54 ..mu..m can be both pyrophoric and explosive. Pyrophoric powders should be collected and stored underwater or under inert gas cover to reduce the flammability hazard. Opening sealed containers of zirconium stored underwater should be attempted with caution since hydrogen may be present. The factors that influence the ignition temperature have been explored in depth and recommendations are included for the safe handling, shipping, and storage of pyrophoric or flammable zirconium.

The powder is nasty stuff. Solids, as we have here, is not.

Now, anything at all will burn if you get it hot enough but surely no one is trying to state that after a couple of years in those ponds then the zircalloy will still be hot enough to ignite are they? If this were true then we’d never be able to refuel a reactor would we? For as soon as we draw out a tube then it will go bang.

Is there something I’ve missed here? Or are these people really talking bollocks of such amazing size?

Others have issued even more dire warnings, with Charles Perrow, a professor emeritus at Yale University, warning: “The radiation emitted from all these rods, if they are not continually cool and kept separate, would require the evacuation of surrounding areas, including Tokyo.

“Because of the radiation at the site, the 6,375 rods in the common storage pool could not be continuously cooled; they would fission and all of humanity will be threatened, for thousands of years.”

Charles Perrow is a sociologist for fuck’s sake!

24 comments on “Err, Why?

  1. Charles Perrow is a sociologist for fuck’s sake!

    Well, Tokyo is a society, isn’t it? Therefore he can authoritatively pronounce on the effects on society of his completely made-up physics?

    Anyway, we all know what radiation near Tokyo leads to. Godzilla and huge robots fighting each other. It’s been on TV and everything.

  2. Perrow may have been a sociologist: more to the point, he is a Greenshirt.

    What he says should be treated as should all Green pronouncements: regarded as an outright lie unless corroborated by non-Green third parties.

  3. Also noted:

    The radiation emitted from all these rods, if they are not continually cool and kept separate, would require the evacuation of surrounding areas

    Okay – if the rods get close enough, in the correct geometry, so you get criticality, then you’ve got a problem. But I suspect that the number of rods in each tank and the basic geometry of the tanks is designed so this cannot happen.

    Absent that, the radiation emitted from the rods is a function of their temperature? Is the weak nuclear force really affected by temperature? Even if the rods containment is breached, does that actually increase the radiation emitted (contamination being a completely separate thing.)?

    My physics is a bit elderly but I strongly suspect the answer to those three questions is a fairly emphatic “no”.

  4. Guys, if you search for ‘Fukushima professor’, Perrow springs up a couple of times in the first five results.

    Therefore he’s an authority, yeah?

  5. In very hard rock we use aluminium powder in the Ammonium Nitrate and Fuel oil blasting agent mix to give the explosion extra kick. This doesn’t mean that all airplanes and aluminium coke cans will explode if you leave the things baking in the sun.

  6. Tim Worstall & Surreptitious Evil

    I would like to join with UK Liberty and note, in keeping with the spirit of the age, that Charles Perrow is PROFESSOR EMERITUS at YALE UNIVERSITY. He therefore knows what he is talking about, whatever the subject. So shut the fuck up, both of you!!!!

  7. explanation here -

    Explanation for what?

    Broken fuel rods mean contamination – either outside or within the next containment boundary. They do not mean either criticality or any increases in alpha or beta decay radiation emissions.

  8. He speaketh Science! Burn the denier!!

    I am sure that everything he says has been peer reviewed.*

    * by other sociologists.

  9. Zircalloy does not spontaneously combust on exposure to air

    That’s true. But it does oxidize exothermically if heated in steam. And of course fuel rods, even spent ones, do get hot, and will over time boil off their cooling water if there’s a systems failure. So if you leave a cooling pond untended for a few days, you may well end up with a runaway zirconium cladding fire. This report discusses the risk.

    I can’t see any danger of criticality just because the cladding burns. But it would be a very ugly business.

    In practice even if the site became too radiactive for human access to the ponds, one would expect it to be possible to get water to them in some way. From a helicopter, perhaps. With a very well paid pilot.

  10. This Perrow fella’s got an ology hasn’t he? So he’s a scientist! Game set and match for the fluffy greenies! All these so-called nuclear scientists are just in the pay of Big Nuclear, ummm, Chernobyl Chernobyl Chernobyl. Won’t someone think of the polar bears?

  11. But it does oxidize exothermically if heated in steam.

    There isn’t much that oxidises endothermically.

    In practice even if the site became too radiactive for human access to the ponds,

    Please note the huge difference between “a human trying to access will break some regulatory radiation exposure limits” and “this is now so radioactive that a human will die before achieving anything useful”. As Chernobyl showed, if the reward to society is perceived to be high enough, people will do remarkably dangerous things.

  12. So if you leave a cooling pond untended for a few days, you may well end up with a runaway zirconium cladding fire.

    That’s not what the report you link to says. It says operators have a few days to intervene once the boil off process begins, and even then it is far from certain at which point a fire would occur.

    This report discusses the risk.

    And concludes that it is low, with the likelihood of a zirconium fire being “very low”. Did you actually read it?

  13. A key concern is that another major earthquake could cause cracks in the pool…That would allow the zirconium alloy cladding to ignite…

    TimN: The report says that “Fuel Uncovery” due to a seismic event is a very low risk. But the question Tim W asked, based on the quotation above, assumes that the earthquake and coolant loss has happened. So the report’s estimate of earthquake risk is not relevant. What’s relevant is the risk of a zirconium fire once the fuel has been uncovered. Did you bother to find out what we were talking about before you posted?

  14. Ah yes, the PaulB method of internet commentary:

    1. Make a bold statement which runs contrary to the OP and general comment thread, in order to make yourself seem informed and give the impression you have given the topic careful consideration. The more confident the statement the less accurate it is.

    2. Ensure you leave plenty of wriggle-room should your statements be challenged.

    3. Link to a report in order to lend gravitas to your statements, which need not support what you are saying: you merely hope nobody will bother to read it and assume you are quoting it accurately.

    4. When challenged, resort to obfuscation, lies, accusations, and denials making liberal use of the wriggle-room you allowed yourself in no. 2. Make each reply more pompous and condescending than the last to the point that your exasperated opponent calls you a twat.

    5. Huffily remark that you don’t wish to trade insults on the internet, and that you don’t have time to argue any further, before repeating no. 1 in a thread after a brief period of wound-licking on your part.

    We’ve been here before, haven’t we? Let’s both save ourselves some time, eh?

  15. Tim W asked why anyone would think Zircalloy cladding could catch fire, and I answered, mainly by referring him to a report discussing the possibility. Why you have a problem with that I cannot fathom.

  16. @PaulB: Tim W asked why anyone would think Zircalloy cladding could catch fire, and I answered, mainly by referring him to a report discussing the possibility. Why you have a problem with that I cannot fathom.

    It’s a problem because outside of you domain you exhibit the classic symptoms of a book only ‘expert’. You read what someone you trust says but don’t actually know enough of the practice to know they are talking BS.

  17. It’s a problem because outside of you domain you exhibit the classic symptoms of a book only ‘expert’. You read what someone you trust says but don’t actually know enough of the practice to know they are talking BS.

    Actually, he doesn’t even portray the symptoms of a book only expert, he portrays the symptoms of somebody trying to pass himself off as one. On every subject somebody has bothered to take him to task on, with the exception of banking/finance matters, he’s resorted to the same behaviour I’ve described *not once* putting his hands up and saying “Ah, I’ve got the wrong end of the stick”, which happens to us all at some point. His lack of practical experience in the stuff he comments about is blindingly obvious, but don’t let his ability to reference a document he doesn’t understand and obfuscate thereafter into fooling you he’s an expert on anything. Even when his own words are read back to him, he denies writing them.

  18. Thanks for the explanation.

    I’m happy to take this as typical of our occasional spats. I’m not an expert on nuclear fuel pools, but as it happens I have worked in nuclear engineering. I did read and understand the relevant parts of the report, which does treat a zirconium fire as a likely outcome of prolonged uncovery of fuel rods.

    Whereas you skipped to the conclusions, read “very low likelihood”, and went off on one.

  19. I did read and understand the relevant parts of the report, which does treat a zirconium fire as a likely outcome of prolonged uncovery of fuel rods.

    Yes, it does. But you’ve clearly not understood why they have taken this approach. And what the report says is barely relevant to your original comment in its context. As has been pointed out, you have *no* experience other than that which allows you to Google for a report you don’t understand.

    And you’re still a twat.

  20. So I was right in my description of how a zirconium cladding fire can occur, and your dismissal of it was based on a misunderstanding of the risk analysis in the report. But never mind, perhaps you can cover that up by calling me names.

    No doubt you have some quibble remaining with my wording, which we could easily clear up if you’d say what it was. But you won’t, because you need to pretend I got something badly wrong.

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