Bacteria can make underground nuclear waste repositories safer

Naturally occurring bacteria could consume pent-up hydrogen gas in nuclear waste repositories to prevent radioactive leaks, say researchers at EPFL. Scientists may have found an unexpected ally in the long-term disposal of nuclear waste: bacteria. In a recent study, a research team led by EPFL discovered a microbial community made up of seven species of bacteria that live naturally hundreds of meters underground in the very rock layers that have been chosen to host Swiss nuclear waste. Far from posing a threat, they found that, by tweaking the design of nuclear waste repositories, the bacteria could be used to increase their safety by consuming hydrogen that accumulates as the steel canisters bearing the waste corrode. If left unchecked, the gas pressure build up that could affect the integrity of the host rock. They published their findings in the journal Nature . It takes about two hundred thousand years for the radioactivity of spent nuclear fuel to revert to the levels of naturally occurring uranium.