Perhaps the most elegant solution of all would be to pitch excess plutonium into space, firing it into the Sun.
America will need to dispose of more than 50 tons of excess plutonium.
If fast neutron reactors are not available (the normal case), excess plutonium is usually discarded, and forms the longest-lived component of nuclear waste.
And 134 tons of excess plutonium, which the Russians are willing to destroy, are just sitting in storage.
American and Russian officials recently fought over arcane rules that would govern a program to dispose of that 134 tons of excess plutonium.
The Energy Department confirmed today that it would follow a dual track to dispose of excess plutonium from nuclear weapons.
A variation of the thorium idea may allow the Department of Energy to use excess plutonium in commercial nuclear power plants, also without creating byproducts suitable for weapons.
You argue that if excess plutonium from old warheads is used as reactor fuel, it becomes radioactive and thus harder to make into bombs.
But they would have to let the International Atomic Energy Agency inspect such production, and insure that excess plutonium is stored securely.
MOX also provides a means of using excess weapons-grade plutonium (from military sources) to produce electricity.