Nuclear waste eaters: Scientists discover hazardous waste-eating bakteria

Tiny single-cell organisms discovered living underground could help with the problem of nuclear waste disposal, say researchers involved in a study at The University of Manchester. 

Although bacteria with waste-eating properties have been discovered in relatively pristine soils before, this is the first time that microbes that can survive in the very harsh conditions expected in radioactive waste disposal sites have been found.

The disposal of our nuclear waste is very challenging, with very large volumes destined for burial deep underground. The largest volume of radioactive waste, termed 'intermediate level' and comprising of 364,000m3 (enough to fill four Albert Halls), will be encased in concrete prior to disposal into underground vaults.

When ground waters eventually reach these waste materials, they will react with the cement and become highly alkaline. This change drives a series of chemical reactions, triggering the breakdown of the various 'cellulose' based materials that are present in these complex wastes.

One such product linked to these activities, isosaccharinic acid (ISA), causes much concern as it can react with a wide range of radionuclides -- unstable and toxic elements that are formed during the production of nuclear power and make up the radioactive component of nuclear waste.

If the ISA binds to radionuclides, such as uranium, then the radionuclides will become far more soluble and more likely to flow out of the underground vaults to surface environments, where they could enter drinking water or the food chain. However, the researchers' new findings indicate that microorganisms may prevent this becoming a problem.