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Sea Water Could Cause Uranium Pollution From Nuclear Fuel Rods 97

Posted by timothy
from the small-drop-big-bucket dept.
New submitter Required Snark writes "UC Davis researchers have found a mechanism where the sodium in sea water can cause uranium nano-particles to be released from nuclear reactor fuel rods. Normally the uranium oxide compounds composing the rods are very resistant to leaching into water. This could have serious consequences for the Fukushima disaster, since sea water was used for emergency cooling."
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Sea Water Could Cause Uranium Pollution From Nuclear Fuel Rods

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  • COULD have ? we are STILL at that level of acknowledgement ? what happened to the millions of tonnes of seawater which was pumped in to cool exposed radioactive rods and evaporated into high flying atmosphere streams ?

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      It's gradually diluting itself to harmless concentrations as it spreads over the rest of the world.

      • Re: (Score:3, Interesting)

        by ErikInterlude (784049)

        I remember when the Fukushima event was still making headlines people were freaking out because radiation was making it's way to the U.S. I was a little worried myself, but since I work for an air purification company one of the data-crunchers there was able to explain now negligible the impact actually was.

        If it's the same for this seawater issue, then no big deal, I guess. Still, I can't help but be a little disturbed at the idea of radioactive particles from a power plant being spread into the ocean. I w

        • Re: (Score:3, Informative)

          by parens (632808)
          Nuclear submarine reactors aren't cooled with seawater.
          • by camperslo (704715)

            Nuclear submarine reactors aren't cooled with seawater.

            Power plants aren't either, not directly. There's a heat exchanger in-between. The actual reactor coolant has to be ultra-pure not only to reduce corrosion, but to avoid buildup of isotopes that would develop from the impurities and form deposits in the pipes at locations that would increase exposure to plant workers. Of course buildup is also a problem for things like pumps and valves.

            One of the very disturbing things found in Japan when other reactors got a closer look was a plant where a significant a

            • by Coren22 (1625475)

              10,000 years wouldn't be an issue if we reprocessed the ore and just dumped the useless parts into Yucca mountain.

        • by pingbak (33924) on Saturday January 28, 2012 @02:59AM (#38848409)

          Closed loop system. Never exposed to outside water sources.

          • Re: (Score:3, Informative)

            by symbolset (646467) *
            Under normal operating conditions. If the boat sinks all bets are off.
            • Under normal operating conditions. If the boat sinks all bets are off.

              A naval nuclear reactor will have somewhere between 100 Kg and 250 kg of uranium.

              Sealed inside non-corrosive alloys, which are further incorporated into inconel fuel rods.

              Which, in turn, are inside a reactor vessel designed to handle several thousand psi differential pressure.

              Which is inside a reactor room which is designed to handle rather more than another 500 psi differential pressure.

              Which will then be sitting on the bottom of the

              • by treeves (963993) on Sunday January 29, 2012 @03:15AM (#38855043) Homepage Journal

                All that's true, but occasionally we (I was a submariner back in the late 1980s-early 1990s) will intentionally discharge a small amount of primary coolant into the ocean, e.g. to correct a chemistry imbalance.
                It does not contain fuel or fission products, but it is somewhat radioactive (e.g. activated corrosion products), and some of the radioactivity is moderately long-lived (e.g. Co-60, half-life=5.27 yrs.)
                Again, even a small part of the ocean is really big compared to amount of stuff discharged.

            • by pingbak (33924)

              Even if the sub reaches crush depth, the reactor itself is very heavily protected. Note that I'm not saying that exposing the reactor core to seawater is impossible, but given all of the safeguards, it's highly unlikely.

        • by camperslo (704715)

          I remember when the Fukushima event was still making headlines people were freaking out because radiation was making it's way to the U.S. I was a little worried myself, but since I work for an air purification company one of the data-crunchers there was able to explain now negligible the impact actually was.

          I think your friend was half right. Ground-level exposure in the U.S. from inhaling air was low. But when water vapor condenses around particles in the atmosphere, the levels in rainfall can be quite high. The dispersion isn't uniform. Depending on where the higher concentration air currents were and when/where rain fell, overall average can be low while some areas become hot spots. The rain falls on the grass, the cows eat, and then we eat or drink. Most of the significant exposure that people in Swe

      • It's gradually diluting itself to harmless concentrations as it spreads over the rest of the world.

        No, it's becoming more and more potentized as a homeopathic remedy.

    • by MightyYar (622222) on Saturday January 28, 2012 @12:18AM (#38847905)

      what happened to the millions of tonnes of seawater which was pumped in to cool exposed radioactive rods and evaporated into high flying atmosphere streams ?

      Well, if it evaporated, then it certainly didn't take any uranium with it.

      And if it flooded into the sea, it carried some dilute amount of uranium with it. Uranium is mostly harmless. TFA says it will settle onto the sea floor.

    • Re: (Score:3, Insightful)

      by Anonymous Coward

      Do you honestly have any fucking idea how big the Pacific is, or how big the planet as a whole is? Not trolling here, just honest questions. Do you know anything at all about ocean currents or dilution rates expressed not in parts per million, but parts per quintillion over time spans measured not in years or even months, but in days? How about decay rates? How about statistically significant exposure thresholds for even remote potential for damage to cellular structures? For fuck's sake, do you have any id

      • Re: (Score:2, Offtopic)

        by TheLink (130905)

        The Pacific is big but while I'm not so worried about this uranium thing I'm a bit worried about this: http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch [wikipedia.org]

      • by MrKaos (858439)

        Do you honestly have any fucking idea how big the Pacific is, or how big the planet as a whole is? Not trolling here, just honest questions. Do you know anything at all about ocean currents or dilution rates expressed not in parts per million, but parts per quintillion over time spans measured not in years or even months, but in days? How about decay rates? How about statistically significant exposure thresholds for even remote potential for damage to cellular structures? For fuck's sake, do you have any id

  • Re: (Score:5, Informative)

    by AWeishaupt (917501) on Saturday January 28, 2012 @12:11AM (#38847889)
    Uranium release from the UO2 fuel? So what? Uranium is harmless, it's hardly radioactive at all, it's abundant throughout nature, and it's naturally present in seawater. Surely any such analysis of the radiochemistry consequences of adding seawater to the BWR's coolant should focus on the fission products and their radiochemical mobility and transport, not on harmless, insignificant, uranium.
    • by quenda (644621)

      I think we may have a new record for the most trivial, inconsequential piece of "news" that made it to /. merely by being possibly related to Fukushima.

      • by MrKaos (858439)

        I think we may have a new record for the most trivial, inconsequential piece of "news" that made it to /. merely by being possibly related to Fukushima.

        No it's not insignificant. It's either very good news and it means that the radionuclides become less like micro-nutrients to living systems or it's very bad news and this effect make the radionuclides more readily absorbed by living systems, it remains to be seen.

    • Precisely. As an aside, the Uranium and Thorium present in seawater can be extracted for use in nuclear reactors. Not that we would run out of land-based resources for many thousands of years, but it is interesting that nuclear fuel is so energy dense that this is even economically viable. It could also be economically recovered from coal ash, and there is no shortage of that either.

      • by dbIII (701233) on Saturday January 28, 2012 @02:25AM (#38848281)

        As an aside, the Uranium and Thorium present in seawater can be extracted for use in nuclear reactors

        Yes, just as I could marry rich supermodel twins on the day I turn 90 while legally keeping another three wives. Possible, but incredibly difficult to do and entirely pointless. In other words your "can" doesn't match what is in the dictionary but instead has a definition of "somebody somewhere thought one step might be possible so I'm building an enormous fucking house of cards on it and pretending it's a solid pyramid".
        Going from that to pretending that anybody has even roughly worked out costs, and then suggesting it's "economically viable" is an incredible audacious lie. If you are an adult you should be ashamed of what you have written to try to trick people into thinking your pet cause is magic instead of reality. As for the ash thing, if you've actually fallen for that one instead of just trying another even more incredibly stupid lie try googling for Alex Gabbard to find that was yet another one of his works of fiction. If terrorists could easily build nuclear bombs out of coal then one would have been used by now.

        Here's a clue people - if we don't have a process devised that is in any way similar to what is going to be attempted there is no way to work out costs within an order of magnitude let alone work out if something is "economically viable". That's why private funding for leading edge technologies of any kind usually sucks because nobody knows how much things will cost and how much can be gained. "How much will it cost" is a question that can only really be answered reliably after a prototype or pilot plant.

        • by dbIII (701233) on Saturday January 28, 2012 @02:37AM (#38848325)
          There are many Uranium mines already in operation and a lot of accessable Thorium deposits. Getting the stuff from seawater is a hell of a lot more difficult and will be far more energy intensive and then you've still got the same sort of material that you get from digging up and gravity separating the ore.
          The "Uranium is running out" problem was a 1960s thing, partly real due to some reactor designs of the time being very fussy about the isotopes in the fuel, and partly political/military to provide an excuse to build expensive Plutonium fast breeders. Also many other Uranium deposits have been found and exploited since then.
          If nothing else we'll get a hell of a lot of Uranium as a side product from mining Copper in a few places so it makes no sense at all to go after the tiny concentrations in seawater.
        • Re: (Score:3, Interesting)

          by tp1024 (2409684)
          In fact, it's so incredibly difficult and expensive, that it had to be done by Japanese who figured out that it would cost $300 per kg - about 4-5 times of current market prices.

          So, you mean extrapolation of prices is a difficult and error prone process and they could easily be off by a factor of 10? You're right! But does it matter? No!

          1kg of Thorium/Uranium/Plutonium (it really doesn't matter much in breeding reactors) is sufficient to produce 1MW of electricity for one year. That's almost 9 million kW
          • by dbIII (701233)
            It's not even that - "it had to be done" didn't happen. Nobody extracted anything they just suggested it might be possible in a paper about the concentration of elements (not compounds, just elements) in seawater. It's a bit of a step from there to determine what form the Uranium is in AND THEN determine how you extract it as a metal. That makes any cost estimates an exercise in wishful thinking since they don't have a clue what is needed. Of course the original poster probably thinks it's in little nug
            • Re: (Score:2, Flamebait)

              by tp1024 (2409684)
              Wrong. [google.com]
              • "Artificial Seawater"
              • Instead of providing a source for your $300 per kilo you've put up a distraction. Shouldn't you be a bit disgusted with yourself?
                Back onto topic, the paper I saw years ago was some Japanese economist making a pile of wild guesses based on elemental content alone. If you have anything better (and the source for your $300 per kilo claim) then please put it up without demeaning yourself any furthur with petty little schoolboy tricks.
                • by tp1024 (2409684)
                  Well, there is, for example a three year old paper by Tamada [harvard.edu] describing the process in some detail. And besides, there was a paper published 48 years ago [umanitoba.ca] on the 8th place of the search result that I've shown before that described several methods for uranium extraction, including the predecessors of the approach pursued it Tamada's paper.

                  This casts some doubt on your ability to research the claims your are making. E.g.: "Nobody extracted anything they just suggested it might be possible", "That makes any co
                  • OK that's new but those dollar costs are for the oxide (not the metal) and the collection stage only which is still going to be a lot more expensive than digging it out of the ground. It's turned into one of those "would you believe" jokes as usual for nuclear fanboys stuck in the 1960s where the evidence given turns out to be for a far lesser claim than the fanboy pretends.
                    For those interested in truth instead of magic I'm going to point out that it's a hell of an expensive and energy intensive process to
                    • Yellowcake prices have spiked so it's selling at around $100 per kilo which is a lot more than usual. Mining and extraction costs are of course lower than that. Consider things like that before going on about how wonderful it is to have an optimistic sea water extraction cost three times that.
                      Of course the thing that really pisses me off is the implication that the $300 per kilo is the price for the fuel and pulling a bit of sleight of hand interchanging the element and the hard to reduce oxide. You guys
    • Uranium is harmless, it's hardly radioactive at all, it's abundant throughout nature

      U-238 yes, U-235 no. And nuclear fuel rods are enriched with a fair amount of the latter.

      • by khallow (566160)
        U-235 is not all that radioactive either and it's already a significant amount (several percent) of the uranium present in sea water.
        • by burne (686114)

          3-5% U-235 is typical ready-to-burn nuclear fuel. Raw ore contains 0.7% U-235. 'Enriching' uranium is quite hard and energy-wise very expensive.

          • by khallow (566160)
            My apologies. I'm still within a factor of ten which is good enough for this argument.
    • by mrmeval (662166)

      Prof Navrotsky and crew are the red headed step children of US Davis, studying ways to make nuclear energy more efficient because that's mandated by DOE to get fed grants, this allows the important scientists to study all the fluffy bunny green science. I'm not surprised.

    • Re: (Score:5, Informative)

      by AmiMoJo (196126) <mojo@world3AAA.net minus threevowels> on Saturday January 28, 2012 @07:24AM (#38849079) Homepage

      Uranium certainly isn't harmless as many people who inhaled or ingested it have found out. While it is mostly harmless outside your body because the skin blocks alpha radiation the problems begin when it gets inside and settles in your lungs or accumulates in your bones and organs. It will sit there for decades and case damage to bone, liver, kidney, and reproductive tissues.

      Uranium is a toxic metal and has been shown to produce birth defects and immune system damage in animals. Although it is hard to pin any particular cases of cancer on uranium there are very well known and understood health problems stemming from exposure to it and its decay products like radon. Obviously any creature living in the sea is at risk, as is anyone who eats them or drinks the water.

      Wikipedia has plenty of references: http://en.wikipedia.org/wiki/Uranium#Human_exposure [wikipedia.org]

      • by Anonymous Coward
        So what you're saying is, the Uranium that may have leached into the sea is so dangerous, all you have to do is drink a couple of million gallons of sea water and it'll kill you?
        • No, he's saying uranium isn't harmless.

          What you're saying is that low concentrations make it harmless in seawater.

          What I'm saying is "do you ever eat fish?". If you eat fish, you're eating whatever the fish ate, and whatever that ate, etc etc all the way down the food chain. At the bottom of the food chain is where the millions of gallons of sea water are drank.
          • by greg_barton (5551)

            There's already uranium in seawater, from entirely natural sources, so your fish argument is silly.

    • by MrKaos (858439)

      Uranium release from the UO2 fuel? So what? Uranium is harmless, it's hardly radioactive at all, it's abundant throughout nature, and it's naturally present in seawater. Surely any such analysis of the radiochemistry consequences of adding seawater to the BWR's coolant should focus on the fission products and their radiochemical mobility and transport, not on harmless, insignificant, uranium.

      Indeed, uranium isn't the only radionuclide that Fukushima ejected. Plutonium-239, strontium-90 and cesium-137 (amongst others) were likely candidates. If you seek out my other posts in this thread you'll find I've linked to the science already. [slashdot.org]

  • by sjwt (161428) on Saturday January 28, 2012 @12:24AM (#38847923)

    "Uranium in nuclear fuel rods is in a chemical form that is “pretty insoluble” in water, Navrotsky said, unless the uranium is oxidized to uranium-VI — a process that can be facilitated when radiation converts water into peroxide, a powerful oxidizing agent"

    So the real issue is when you first use a supply of emergency bleach to hold out until your supply of emergency seawater arrives, or god forbid you forget to tell the overnight cleaning crew not to open up the reactor and give a good bleaching?

    • by Guppy (12314)

      "Uranium in nuclear fuel rods is in a chemical form that is “pretty insoluble” in water, Navrotsky said, unless the uranium is oxidized to uranium-VI — a process that can be facilitated when radiation converts water into peroxide, a powerful oxidizing agent"

      Hmm... is there any way that the peroxide (or related free-radical products) could react with the chloride in sea-water to yield hypochlorites?

  • Interesting (Score:2, Insightful)

    by Anonymous Coward

    This could actually be a potential problem for the spread of contamination. Haven't seen Burn's paper yet, but the general theory seems sound.

    Water radiolysis yield these common products
    H2O ---> e-(aq), H*, H2, *OH, H2O2, HO2, H+
    with it's primary products being the H* and *OH radicals which then react with each other to form H2 and H2O2. So peroxide is easily produced.

    In the Fukishima accident, they were concerned with spent fuel rods (extremely radioactive with several trans-uranic elements) in the unco

  • by tp1024 (2409684) on Saturday January 28, 2012 @02:48AM (#38848379)
    You mean minute quantities in addition to the 4.5 billion tons of Uranium already in the oceans? Exactly what does it take to make people realize that Uranium is a perfectly natural part of the Earth?
    • Exactly what does it take to make people realize that Uranium is a perfectly natural part of the Earth?

      Exactly what does it take to make people realize that artificially high local concentrations may have different effects than natural background levels?

      • by tp1024 (2409684) on Saturday January 28, 2012 @03:28AM (#38848487)
        Their existence, while not sufficient, would go a long way. To quote the article: "there is no evidence of long-distance uranium contamination from the plant."

        Why is the existence not sufficient? The radioactivity in Uranium ores, that is indeed problematic in the (comparably) extremely high concentrations that can be found in sub-surface mines, is *not* caused by the Uranium itself. This is exactly the paradox that made Marie Curie investigate what does make this stuff so radioactive. Because the Uranium sure wasn't enough. And the answer turned out to answer to names like radium, radon, polonium, lead-214, lead-210 and a bunch of other elements and isotopes building up over tens of thousands to millions of years or so, with the decay of Uranium to Radium being the crucial step that is just not going to occur in Fukushima Daiichi in historical time periods.
        • by symbolset (646467) *
          The statement would be more convicing with evidence they had looked for evidence.
          • by Solandri (704621)

            The statement would be more convicing with evidence they had looked for evidence.

            Why? The way science works, you assume the hypothesis which results in an observable result is false, then look for evidence that it is true. So the burden of proof is upon those trying to show that uranium has leached into the seawater and spread to distances in concentrations measurably above natural background levels.

            Even if you're skeptical of their finding that the hypothesis is false, heck even if it turns out that

  • by pingbak (33924) on Saturday January 28, 2012 @02:57AM (#38848399)

    Sure, uranium could leach into the ocean. But at what concentration? And at what expected half life?

    Uranium has a long half life, so the risk is tolerable. Estimates have been that more uranium is in sea water than will ever be mined. Good reason for some people to stay put of the water, More space for the rest of us to play, I guess.

    I'm always surprised at the number of people who think that long lived isotopes are more dangerous than short lived ones.

    • I'm always surprised at the number of people who think that long lived isotopes are more dangerous than short lived ones.

      I can't speak for anyone else, but I lack a lot of knowledge on the science of these issues. Generally speaking, the only time I hear Uranium is in association with man-made nuclear projects. Rarely do I hear Uranium in association with micro-nutrients and naturally occurring sea particles. Until this article appeared, I had never read that there was so much of it in the planet's waters

  • Why is it that pretty much all nuclear disasters were from stupid mistakes?
    I mean, whos bright idea was it to place the backup diesel gensets in the basement right next to the ocean?
    That obvious design flaw should had been fixed at least 20 years ago.
    • by Jayemji (1054886)
      Because it pretty much always takes a stupid mistake to generate a nuclear disaster. Reactors are generally quite safe unless you really screw the pooch.
      • by rubycodez (864176)
        in fact, you have to screw more than one pooch to have a reactor disaster, they are pretty much proof against any single horrible fuck-up. congrats to TEPCO on screwing three (at least) pooches that made this disaster.
    • by symbolset (646467) *
      Well normally I'm on the other side of this one, but hindsight is 20:20.
    • Re:Meh.... (Score:4, Insightful)

      by Solandri (704621) on Saturday January 28, 2012 @12:51PM (#38850307)
      They weren't right next to the ocean. They were about 8 meters above the previous highest recorded tsunami level in that area, so assumed to be safe from flooding. I mean, what are you going to do? The largest recorded tsunami was 524 metershigh [geology.com]. Are you going to require every nuclear plant to be relocated at least 525 meters above sea level because of this "obvious design flaw"?

      The not-so-obvious design flaw was that the generators were all in the same location. So although they had multiple generators for redundancy in case some failed, that redundancy was made useless by a common failure mode. You want them in different locations, different makes, with different parts and connectors, and running off of different fuel tanks.
  • by Anonymous Coward

    "Sea Water Could Cause Uranium Pollution" sounds like the opposite of "Uranium Could Cause Sea Water Pollution". Bad, bad sea water, polluting our uranium!

  • The sky is falling. Again!
  • Look it up. Natural seawater contains 3 tons of Uranium per cubic kilometer (3 ppb). How much ocean is within 1 km of the Fukushima plant?

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