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Cleaning Uranium Waste with Bacteria
Roland Piquepaille writes "Nuclear bombs can kill people even if they're not used. In the U.S. alone, the Department of Energy estimates that more than 2,500 billion liters of groundwater are contaminated with uranium as a consequence of nuclear weapons production. In "Uranium 'pearls' before slime," scientists from the Pacific Northwest National Laboratory (PNNL) say they discovered that some common bacteria could "convert deadly heavy metal into less threatening nano-spheres." In fact, these bacteria can convert soluble radioactive uranium into a non-toxic solid form called uraninite. Still, more research needs to be done before using these bacteria on a large scale, but it's a step in the good direction. Read more for additional references and photos showing how Shewanella oneidensis can help us to decontaminate groundwater at nuclear waste sites."
Didn't anybody ever watch TROMA's "The Toxic Advenger". What's going to happen to these bugs after they've eaten all the plutonium and come after the people? Oh, the humanity!
If one were to input this common bacteria into a operating nuclear reactor, would that mean that the reactor would clean itself the longer it operated? Of couse there would have to be a way to seperate core material from already used fuel to prevent the bacteria from shutting it down. But if it were possible, wouldn't this be be more efficent than summarily throwing away the whole fuel rod assembly? Look forward to seeing your all's response's.
We cannot simply exploit these living animals for our own selfish needs. These bacteria need to be allowed free range so they can live healthy, happy, natural lives without human oppression. We have a consistent track record of exploiting animals for our own use - even torturing them for our own entertainment. These bacteria need to be protected immediately! Oh won't someone please think of the bacteria!
"Nuclear bombs can kill people even if they're not used. In the U.S. alone, the Department of Energy estimates that more than 2,500 billion liters of groundwater are contaminated with uranium as a consequence of nuclear weapons production. Ok, let's be scientific here. First, the proposed problem is not that unused nuclear bombs can kill people themselves, but that the production of nuclear weapons creates a radioactive byproduct that is alleged to be dangerous. Where is this byproduct located? Is it contaminating known in use reservoirs? Is it all far away from any humans that would use this groundwater? Or is it somewhere in between? Assuming people are ingesting the radioactive byproduct, how many rads are they irradiated with? Is it a neglible amount? Are they dying in their showers? This story hasn't bothered to be consistent with its own terminology, and I don't think it's too early to call it hysterical fearmongering sans hard data.
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All these awesome science stories, cutting edge stuff that not even digg or fark dares to post.
(looks closer) Oh. Its a roland piquapallawhatever submitted story.
(is eaten by a grue)
If you want to get a decent dose from uranium you are either going to need a lot of uranium around you or a very long time to be exposed.
Look at how wildfire has actually thrived in the radioactive area contaminated by the Chernobyl accident. That radioactive area is called the Chernobyl zone and has been devoid of people for more than 20 years. The absense of people (who are known killers of wildlife) has enabled wildlife to re-populate the Chernobyl zone.
In the long run, the stupidity (also known as nuclear weapons and global warming) of man may exterminate mankind, but nature will survive. Heed the wisdom of the Native Americans: "The earth does not belong to man; man belongs to the earth."
No uraninite.
God spoke to me.
Second, U-238 is 99.28% of natural uranium. U-235 is 0.72% Weapons grade, or enriched uranium is natural uranium that has a much higher percentage of U-235.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
Uranium (natural, enriched, or depleted) is both chemically toxic and radioactive. The article talks about using bacteria to reduce chemical toxicity of this metal. The radioactivity will remain. Chemical toxicity of uranium waste will kill you before its radioactivity does. This is not to say that radioactivity is not a concern.
Depleted uranium, for example, is only about half as radioactive as naturally-occurring uranium. However, its radioactivity has a cumulative effect. If you are breathing depleted uranium particles or drinking water contaminated with depleted uranium, the radioactive particles will be deposited in your body and radioactivity levels and its effects on your health will grow with time.
Depleted uranium is used by the US (among a few other countries) in anti-armor ammunition. Hundreds of tons of this stuff have been dispersed in Kosovo, Iraq, and Afghanistan. When that artillery shell hits a tank, its depleted uranium content burns and turns into radioactive aerosol, which can stay in the air for days and can be carried by wind dozens of miles. When this radioactive dust eventually settles, it penetrates underground with rainfall and contaminates ground water.
It was also discovered that, for example, depleted uranium ammunition used by the US in Kosovo, contains trace elements of enriched plutonium, which is not good news either. If you want to test the long-term effects of radioactive waste in ground water on yourself but don't feel like moving to Kosovo, Maryland would be an adequate alternative.
I want these motherfucking bacteria off this motherfucking uranium.
Reading through the comments so far, there seems to be some misunderstanding of the work by the PNNL crowd and of bioremediation in general. My research group here at Argonne National Laboratory (which outside of Chicago) collaborates with the folks from PNNL. In fact, I am writing this very early on a Sunday morning while measuring the oxidation state of uranium using X-ray Absorption Spectroscopy at the Advanced Photon Source in samples from a collaborator at Oak Ridge National Laboratory, which, like PNNL, is a center of research into uranium bioremediation.
First, a few words about the concept of bioremediation. The Department of Energy became interested in bioremediation of metallic contamination after the extensive success of bioremediative techniques for cleaning up organic contamination -- things like benzene or trichloroethylene. The basic idea is that you dose the ground with bacteria that can metabolize the organic contaminant, let the bugs happily live their lives, then in the end the ground is much cleaner than before. Variations on this technique are in wide use for many organic contaminants and in many places around the world.
The Department of Energy's started several years ago to fund research into using similiar concepts to clean up ground water contamination associated with various sites where materials for nuclear weapons or nuclear fuel were produced. There are several sites in the US where the groundwater has elevated levels of uranium and other metals. Bioremediation is attractive because it involves remediation in situ. The ground doesn't need to be dug up, which introduces a whole slew of other problems into the mix.
Unfortunately, metals are different from organics. When a bacterium metabolizes benzene, the benzene goes away. When a dissimilatory metal reducer, like Shewanella, respires on a uranium compound, the most it can do is change the chemical state of uranium. It is impossible to turn the uranium into some other element. As several other posters have pointed out, uraninite (the end product of Shewnella's respiration of uranium compounds) is still radioactive and it is still toxic.
However, uraninite is not soluble. The uranium in the ground water is in a soluble form and therefore will flow through the ground and find its way into rivers and into drinking water supplies. Uraninite is highly insoluble. When Shewnella converts soluble uranium into uraninite, the uraninite particles adhere to the rocks in the ground.
Thus uranium bioremediation is a containment-in-place strategy. The danger of the contaminated sites is that the contamination will spread. The uranium-polluted site will still be polluted after the Shewnella has done its thing, but at least the uranium will not move out of the contaminated site. And that's the point of the DOE's bioremediation strategy -- to keep a problem that exists from spreading and becoming a bigger problem.
2.5 trillion liters is a vanishingly small amount compared to all the fresh water (not to mention sea water) on Earth. There are 1.4 trillion cubic kilometers of sea water and about 6 billion cubic kilometers of fresh water.
How much nuclear waste is there? Less than 250,000 tons, or 250 million kilograms, of high level waste in the whole world. If even as much as one one-hundredth of this waste were actually contaminating the groundwater in question, it would be at a concentration by weight of approximately (2.5 million kg) / (2.5 trillion kg) = 1:1,000,000.
You could drink a liter of this mixture, with no more ionizing radiation than you get from spending a day in a granite building breathing radon-contaminated air, or living for a few days at the altitude of Denver.
Small quantities of radiation are harmless. The linear no-threshold model of radiation dosimetry is a crock. Life evolved in a constant bath of terrestrial and cosmic radiation, and has very efficient mechanisms for repairing DNA damage from it.
(All quantities gleaned from Wikipedia)
Too much Law; not enough Order.