Dr James Hansen is rightly admired for his scientific and political work drawing attention to climate change. His advocacy of nuclear power ‒ and in particular novel Generation IV nuclear concepts ‒ deserves serious scrutiny.

In a nutshell, Dr Hansen (among others) claims that some Generation IV reactors are a triple threat: they can convert weapons-usable (fissile) material and long-lived nuclear waste into low-carbon electricity. Let's take the weapons and waste issues in turn.