TOLERANCE TO NUCLEAR RADIATION. “Exposure to high environmental radiation dose also leads to substantial energy expenditure in repairing radiation-induced damage. Bacterium Deinococcus radiodurans is the focus of numerous studies and is the most radioresistant microbe with a lethal dose (LD10) at 15 kGy.”
https://royalsocietypublishing.org/doi/10.1098/rsif.2016.0459