The unexpected influence of microbiology on the disposal of radioactive waste

The safe disposal of radioactive waste in repositories constructed deep underground might not sound like a topic that requires much input from microbiologists, but a surprising amount of work has been carried out around the world on how microorganisms might be beneficial or harmful for the safe containment of such waste. The UK has a legacy of radioactive waste from activities such as power generation, medical applications, defence and research. This material is currently securely stored at sites around the UK. The UK government, and those of many other countries have identified that the best and safest approach to long‐term management of this waste, in particular, higher activity waste, is through ‘geological disposal’ (placing the waste in carefully engineered chambers deep underground). This repository will be constructed between 200 m and 1000 m below the surface, in a geological setting that has been carefully selected for its ability to contain the waste for hundreds of thousands of years and will isolate waste until harmful radionuclides have decayed sufficiently. The repository itself will be highly engineered and contain multiple barriers (the last of which is the mass of rock between it and the surface) designed to limit any release of radionuclides. The UK government published a White Paper in 2014 setting out how it will implement geological disposal and is currently undertaking a national exercise collating information about the different types of rocks that occur to depths of about 1000 m beneath England, Wales and Northern Ireland.