Some of those countries don't have nuclear weapons. What do they produce plutonium for?

They don't all produce separated plutonium, this also includes those that produce enriched uranium, which is also fissile.

The three reasons to produce fissile material are weapons, non-explosive military uses and civilian power reactors. Even many of the weapons states aren't producing new fissile material for weapons these days, they have more than enough.

Reactors?