Environment

Newly-discovered waste-eating bacteria could help in nuclear waste disposal

Newly-discovered waste-eating ...
A bacteria found in England that can survive in harsh alkaline conditions could be used to stabilize nuclear waste disposal sites (Image: Shutterstock)
A bacteria found in England that can survive in harsh alkaline conditions could be used to stabilize nuclear waste disposal sites (Image: Shutterstock)
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A bacteria found in England that can survive in harsh alkaline conditions could be used to stabilize nuclear waste disposal sites (Image: Shutterstock)
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A bacteria found in England that can survive in harsh alkaline conditions could be used to stabilize nuclear waste disposal sites (Image: Shutterstock)

"Extremophile" bacteria have been found thriving in soil samples from a highly alkaline industrial site in Peak District of England. Although the site is not radioactive, the conditions are similar to the alkaline conditions expected to be found in cement-based radioactive waste sites. The researchers say the capability of the bacteria to thrive in such conditions and feed on isosaccharinic acid (ISA) make it a promising candidate for aiding in nuclear waste disposal.

In Europe, intermediate-level waste (ILW) generally refers to material that contains high amounts of radioactivity that requires shielding, but not cooling. It includes resins, chemical sludge, metal nuclear fuel cladding and contaminated materials from reactor decommissioning, and is often disposed of by being solidified in cement or bitumen before being buried in underground vaults.

However, when ground waters eventually reach these waste materials, they react with the cement and become highly alkaline. This prompts a series of chemical reactions that trigger the breakdown of various cellulose-based materials present in the waste, resulting in the production of, amongst other things, ISA.

This is a concern because ISA has the ability to react with a wide range of unstable and toxic radioactive isotopes. If it binds to radioactive isotopes such as uranium, the toxic material become far more soluble, increasing the risk it will flow out of the underground vaults and make its way to the surface where it could contaminate drinking water or enter the food chain.

It is this process researchers at the University of Manchester believe the waste-eating bacteria could derail thanks to their ability to live in the highly alkaline conditions and use the ISA as a source of food and energy. They are also able to switch their metabolism to breathe using other chemicals in water, such as nitrate and iron, when there is no oxygen available – which is likely in underground nuclear waste disposal vaults.

The group is studying the biological processes the bacteria use to survive under such extreme conditions, as well as the stabilizing effects they have on radioactive waste.

"We are very interested in these Peak District microorganisms," says Professor Jonathan Lloyd, from the University of Manchester's School of Earth, Atmospheric and Environmental Sciences. "Given that they must have evolved to thrive at the highly alkaline lime-kiln site in only a few decades, it is highly likely that similar bacteria will behave in the same way and adapt to living off ISA in and around buried cement-based nuclear waste quite quickly.

"Nuclear waste will remain buried deep underground for many thousands of years so there is plenty of time for the bacteria to become adapted. Our next step will be to see what impact they have on radioactive materials. We expect them to help keep radioactive materials fixed underground through their unusual dietary habits, and their ability to naturally degrade ISA."

The team's findings appear in the Multidisciplinary Journal of Microbial Ecology.

Source: University of Manchester

9 comments
zevulon
the headline on it's face is nonsense. nuclear waste, 99% of the waste out there by weight and 'tail risk' of massive catastrophic problems, is just spent fuel rod assemblies that are cooling in pools , most of which are located in or near reactor cores in operation. there is nothing bacteria can do to this waste to make it safer. safer means vitrification and or casking it, or , in a real fantasy world------'burning' it in fast breeder or other 'recycling' reactors. the final method of dealing with this waste to ensure it does not pose a risk of exploding off in a melt down at a reactor ( as in fukushima), is simply to ship it out to the deep ocean, preferably over a deep ocean trench that subducts into the mantle like the marianas, and to simply dump it into the deep ocean letting it sink 5 miles or more down in the water column. most people consider this wrong or unethical or dangerous, but it in fact is farther and more inaccesible than the moon. once at that depth, it would be totally unrecoverable . and radionucleotides don't float upwards. teh assemblies would sink. bacteria won't solve anything. and decades of billions of dollars spent on digging 'empty caves' like yucca mountain will not yield a solution to nuclear waste storage.
Slowburn
@ zevulon Using current tech 97% of a spent fuel rod is a valuable commodity and the rest can be neutron bombarded until useful or becoming a short half-life to harmless. Calling know processes "fantasy" is a good indication on the mental levels of the anti-nuclear crowd and there dedication to rational debate. The fleet that was scuttled after the nuclear tests in the pacific because the ships were too hot to handle became safe after about fifty years which would indicate that irradiated steal from the reactor core should be safe after less than four hundred years and the Yucca Mountain facility can guarantee that no matter what the Green movement has to say.
Ramon
@slowburn thanks for degrading my mental levels, inso doing ,preventing any good discussion about nulcear energy. Anyway, safe garding nuclear waste for 400 years is an interesting job, I think many companies will be interested in that: work guaranteed for 400 years ! BUT : I think its fair/economical responsible and logical to ask the companies which produce(d) the waste generating profit, to make a deposit in a fund to guarantee that those costs are securly covered for the full 400 years and in no way any of these costs will be for the tax payer anywere in future.
Brian M
@zevulon Nothing misleading in the headline - article is about bacteria that may reduce the risk of isosaccharinic acid(ISA) in intermediate waste that needs shielding but not cooling. There are no claims that bacteria can reduce the radioactivity levels of the waste!
Mel Tisdale
I am not sufficiently knowledgeable about nuclear processes to join in the squabble between the above commenters. What I do know is that we need nuclear power of some sort if we are to combat climate change in any meaningful way. Wind farms and solar panels are widely thought not to be up to the task. We need an honest discussion regarding just what climate change is really going to mean to our species and what solutions are realistically available (Is thorium as good as it seems to be? Is there enough uranium if is isn't? Is there enough time to build the reactors? Etc. Etc. One problem is that so much of mainstream media is desperate for revenue that it can be bought off by rich oil tycoons who are billionaires and can hardly be said to need the extra profits. The result is that the politicians, who themselves are often for sale, don't have a the public outcry that they should be facing. One good thing, if 'good' is appropriate, is that climate change is widely believed to be snapping at our ankles more and more and so the time will soon come when children will be able to accuse their parents of not acting responsibly when they had the chance. At least I will be able look my son in the face and say in all honesty that "I tried." I would just prefer it to be the case that my son is never suffering so much from climate change that he feels the need to challenge me and my generation.
zevulon
slowburn, i am the opposite of an environmentalist. i call fast breeders fantasy because they are political impossibilities. people like yourself emphasize what is technologicially possible. this is nice. i know what you know about this, more or less. what you fail to inform yourself about is why the entrenched stakeholders have the persistent ability over decades to prevent, or help prevent sensible solutions. yucca mountain is nonsense, because if you read the history of yucca, the money allocated to yucca was done so for a covert military poject. there never was an intention to bury nuclear waste. it was a huge massive 10 billion dollar lie. there is AMPLE evidence of this, which points to the reality that nuclear waste disposal simply is a political football that can be used by politicians to steal money. digging holes in the ground is nonsense. first this is first. build a mobile casking plant, a mobile vitrification plant, or a method of loading the waste onto ships/barges that will be sunk in the deep ocean. those are verifiable plans that are done directly TO the waste. no nonsense of digging massive cave tunnels that are never EVER photographed or audited. we can leave that political chicanery to history. TO brian,- you are correct. but the spirit of scientific 'research' should be to solve meaningful problems. science has been a business like any other businesses, and scientists will take money any way they know how. unfortunately bioremediation of nuclear waste is utter nonsense research from the practical perspective of addressing a major issue. a VERY MAJOR issue. and if anything i'm using this nonsense impracticality to bring attention to priorities. there is nothing misleading about valid science being impractical and drawing away attention from the PRIORITIES of society in solving major problems. you are correct. but there is something called framing the debate. articles about nuclear waste like this frame the 'debate' simply by ignoring the 'debate'. as if there is none. there is a debate. it is VERY IMPORTANT. nuclear waste storage is , without question , one of the bigger problems of the united states, in the not so long run. while many do gooders out there who give speeches for google and get paid to get ph.ds in burning u235 thorium and intermediate radionucleotides----------in the real world , there are actual pools located all over the u.s. with millions of tons. yes millions, of fuel assemblies boiling/evaporating water. many of the so called 'environmental' problems of the u.s. are complete lies manufactured by the media to push a cause and advertising and money making for someone somewhere. taxes, carbon credits, etc.... always money to be made. but why is it , with such a massive problem of fuel assemblies, TICKING TIME BOMBS ( whether by the statistically guaranteed processes of rotting/rusting/accident or by being subject to attack by theives, or even the highly unlikely terrorists/foreign governments) of epic proportion everywhere in the u.s. , nothing is being done about it other than using it as an excuse to dig 10 billion dollar holes int he ground and fund practically useless bioremediattion research like that above?
ezeflyer
Anything that helps control nuke waste just gives Big Nuke reasons to make more nuke waste.
Slowburn
@ Ramon Personally I am tired of having rational thought being shouted down being called good discussion. If you want good discussion denounce and silence the people on your side that make it impossible. Fukushima Daiichi road out an earthquake more than ten time more powerful than what was thought possible for where it was built and a tsunami that over topped all the tsunami barriers along that section of coast apparently contaminated the fuel supply to the backup generators causing them to fail and the resulting loss of electricity causing the pumps to stop causing a meltdown is being used as "proof" that we must never build another nuclear powerplant to a design that uses the reactor core's heat to provide passive coolant circulation. I like gamma emitters like neutron bombarded steel for other jobs. Make the water intakes for powerplants to public water supplies from gamma emitting steel and you won't have a problem with bio-fouling. Put in ballistic tanks and you won't accidentally create a problem with invasive species. Would you say burying the "waste" at say Fort Knox deep under live firing ranges cost taxpayers money to guard?
Anumakonda Jagadeesh
Breakthrough in controlling Nuclear waste. Dr.A.Jagadeesh Nellore(AP),India