Information supplied by Brian Van Straalen, Computational Research Division, Lawrence Berkeley Lab, USA, crd.lbl.gov, August 2004

There are actually two kinds of breeder reactors.

How do we get the Plutonium-239 for our atomic bombs? We built reactors fueled with Uranium-238 whose only job is to create Plutonium-239. These systems are some of the best-guarded plants in the world. Our weapons grade Plutonium is safe. And we use the stuff over and over and over, as necessary, to keep our supply of weapons grade Plutonium up to date and available.

A fast breeder reactor intended for energy production would not use this process. It produces a mixture of Plutonium-239, 240, 241 and 242 as well as U-238 and residue U-235, as well as a mish-mash of other short lived radioactive isotopes.
It is essentially impossible to separate out the Plutonium-239 from the other isotopes in sufficient purity to use it for bomb making. The British tried it, the Russians tried it, the French tried it, and we tried it, but nobody did it very well, even though we had the best scientists and all the money in the world to throw at it.
For energy purposes it is just important to enrich the heavy isotopes all together, not seperate them.

If you try to make a bomb with such a mixture of Plutonium isotopes, forget about it - it won't work, ever. We're talking about the laws of physics, Greenpeace notwithstanding. Unless you have pure Plutonium-239, your bomb will fizzle. So throwing away all that valuable nuclear fuel to prevent terrorists from making a bomb that won't work anyway is just plain dumb.

A fast breeder reactor is capable of producing much more energy and only produces short lived (30 to 40 year half-life) radioactive waste.