A nuclear reactor designed to burn up surplus Cold War plutonium has been closed by the US Department of Energy. Initially it was meant to cost $1bn. So far it has cost $4bn. To complete and operate would cost $25-34bn.
An unexpected outcome of the Fukushima nuclear disaster is that the UK's Sellafield nuclear site - already the world's biggest plutonium repository - is set to store even more of the radioactive, fissionable metal.