Growing interest in nuclear power is often hindered by the question of what to do with the radioactive byproducts. One solution is to bury them. In Mol, Belgium, at the HADES research center, scientists have discovered communities of microbes living in the clay surrounding structures that house nuclear waste. Some species of microorganisms are known to have detrimental effects on the materials used for these structures. Researchers have delved hundreds of meters underground in search of what kinds of microbial communities are present, and what relationship they might have with the poisonous compounds we've introduced to them
Despite very low energy and nutrient levels, scientists were surprised to find rich communities of metabolically active microbes. They captured images of the organisms using a scanning electron microscope, something that previous studies had attempted, but failed to do. In fact, of the ten samples taken at 225 meters below the surface, all ten SEM images showed signs of life. Beyond the initial discovery, scientists were further interested in the diversity of the communities. Rated on a diversity index, the communities observed had an above average number of species. This is important because it supports recent claims that microbial growth can be considerably diverse in subterranean clay environments, usually thought to be too low on nutrients to be such hosts. Furthermore, the diversity itself was diverse, so to speak; as the abundance of essential nutrients shifted, so did the type of microorganism with the metabolism to thrive on it.
And about the radioactive waste? The researchers found all of the communities to be healthy and functioning as would be expected. But in the case of storing poisonous compounds in (possibly) degradable containers, this might not necessarily be a good thing. More needs to be done to understand these communities.