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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."
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.
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.
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.