Wade Allison, Emeritus Professor of Physics, Oxford University, UK: Nuclear energy can affect life when a nucleus decays, releasing energy as radiation. Everything, even our own bodiees, contains some natural radioactivity, and nuclear radiation shines on us from space too. If it had been really dangerous, life would have died out aeons ago, when radiation flux was more intense than it is today. To survive the oxidative damage caused by radiation and oxygen, life has evolved a series of amazingly clever design features and strategies.