Comment by GuB-42

The problem with the stuff that powers mars rovers (RTG) is that gives off constant power. If your RTG gives off 100W, you will always get 100W, no more, no less, until it progressively decays on the scale of decades. You can't even turn it off.

The energy density is great, but the power density is really bad. For most applications, you still want a battery in addition to the RTG.

I don't know how easy it is to make a nuclear bomb from them, it is not the right isotope. You can probably make a nuclear exploding thing, like a dirty bomb, but not the nuclear bombs we know.