clipped from: news.bbc.co.uk   
A bottle discarded at a waste site in the US contains the oldest sample of bomb-grade plutonium made in a nuclear reactor, scientists say.

The type of plutonium in the bottle - known as Pu-239 - has a half-life (the time it takes for the radioactivity to fall by half) of 24,110 years.

Weapons-grade plutonium (American Chemical Society)